This document summarizes a research paper about congestion control, routing, and scheduling in wireless networks with interference cancellation capabilities. It discusses using successive interference cancellation (SIC) to allow multiple concurrent transmissions and increase network capacity. The paper formulates the joint congestion control, routing, and scheduling problem and solves it in a distributed manner using dual decomposition. It develops a decentralized algorithm for link scheduling under the physical SINR interference model that coordinates local transmissions and achieves similar results to centralized greedy maximal scheduling. The paper evaluates the performance gains from SIC and shows that network flows can achieve up to twice their rates compared to networks without interference cancellation.
A New Paradigm for Load Balancing in WMNsCSCJournals
In this paper, we address the problem of load balancing in Wireless Mesh Networks. We consider a Cluster Based Wireless Mesh Architecture in which the WMN is divided into clusters that could minimize the updating overhead during topology change due to mobility of mesh nodes or congestion of load on a cluster. Each cluster contains a gateway that has complete knowledge about group memberships and link state information in the cluster. The gateway is often elected in the cluster formation process. We consider load of gateways and try to reduce it. As a matter of fact when a gateway undertakes to be an interface for connecting nodes of a wireless mesh network to other networks or internet, there would be some problems such as congestion and bottleneck, so we introduce a new paradigm for these problems. For solving bottleneck we use clustering to reduce load of gateways and after that by use of dividing cluster we prevent from bottleneck on gateways. We study how to detect congestion on a gateway and how can reduce loads of it that preventing from bottleneck on gateway and therefore increasing throughput of network to encountering many loads. So we propose an algorithm to detect bottleneck and remedies for load balancing in Wireless Mesh Networks. We also use Ns2-Emultion for implementing and testing the framework. Some qualitative results are provided to prove the correctness and the advantages of our framework.
Defeating jamming with the power of silence a gametheoretic analysisranjith kumar
Dear Student,
DREAMWEB TECHNO SOLUTIONS is one of the Hardware Training and Software Development centre available in
Trichy. Pioneer in corporate training, DREAMWEB TECHNO SOLUTIONS provides training in all software
development and IT-related courses, such as Embedded Systems, VLSI, MATLAB, JAVA, J2EE, CIVIL,
Power Electronics, and Power Systems. It’s certified and experienced faculty members have the
competence to train students, provide consultancy to organizations, and develop strategic
solutions for clients by integrating existing and emerging technologies.
ADD: No:73/5, 3rd Floor, Sri Kamatchi Complex, Opp City Hospital, Salai Road, Trichy-18
Contact @ 7200021403/04
phone: 0431-4050403
The novel applications of sensor networks impose some requirements in wireless sensor network design. With the energy efficiency and lifetime awareness, the throughput and network delayalso required to support emerging applications of sensor networks. In this paper, we propose
throughput and network delay aware intra-cluster routing protocol. We introduce the back-up links in the intra-cluster communication path. The link throughput, communication delay, packet loss ratio, interference, residual energy and node distance are the considered factors in finding efficient path of data communication among the sensor nodes within the cluster. The
simulation result shows the higher throughput and lower average packet delay rate for the proposed routing protocol than the existing benchmarks. The proposed routing protocol also shows energy efficiency and lifetime awareness with better connectivity rate.
The document proposes a clustering-based approach to dynamically allocate bandwidth in wireless networks. It extracts student data from a university's course timetable to predict user distributions over time. It then applies K-means clustering to group buildings into wireless nodes based on expected user loads. This clusters student devices and allows wireless nodes to adapt their bandwidth allocation according to predicted user demands at different times. The approach is tested on a university campus network, extracting student data to predict building loads and applying K-means clustering to allocate optimal bandwidth across wireless nodes over time.
Distance Based Cluster Formation for Enhancing the Network Life Time in ManetsIRJET Journal
This document proposes a distance-based clustering algorithm to improve network lifetime in mobile ad hoc networks (MANETs). The algorithm randomly selects initial cluster heads, then assigns nodes to the closest cluster head based on distance. Simulations in NS-2 and MATLAB analyze energy consumption and residual energy over time. Results show energy use is directly proportional to distance from the cluster head. Nodes near cluster heads conserve more energy, extending network lifetime through load balancing.
MULTI-CLUSTER MULTI-CHANNEL SCHEDULING (MMS) ALGORITHM FOR MAXIMUM DATA COLLE...IJCNCJournal
Interference during data transmission can cause performance degradation like packet collisions in Wireless Sensor Networks (WSNs). While multi-channels available in IEEE 802.15.4 protocol standard WSN technology can be exploited to reduce interference, allocating channel and channel switching
algorithms can have a major impact on the performance of multi-channel communication. This paper presents an improved Fuzzy Logic based Cluster Formation and Cluster Head (CH) Selection algorithm with enhanced network lifetime for multi-cluster topology. The Multi-Cluster Multi-Channel Scheduling
(MMS) algorithm proposed in this paper improves the data collection by minimizing the maximum interference and collision. The presented work has developed Cluster formation and cluster head (CH) selection algorithm and Interference-free data communication by proper channel scheduled. The extensive
simulation and experimental outcomes prove that the proposed algorithm not only provides an interference-free transmission but also provides delay minimization and longevity of the network lifetime, which makes the presented algorithm suitable for energy-constrained wireless sensor networks.
Wireless mesh networks offer high bandwidth Internet access for mobile users anywhere and at any time.
It is an emerging technology that uses wireless multi-hop networking to provide a cost-efficient way for
community or enterprise users to have broadband Internet access and share network resource. In this paper,
we have tried to give a comparative analysis of various Gateway Placement approaches which can be
helpful in understanding which approach will be useful in which situation.
A New Paradigm for Load Balancing in WMNsCSCJournals
In this paper, we address the problem of load balancing in Wireless Mesh Networks. We consider a Cluster Based Wireless Mesh Architecture in which the WMN is divided into clusters that could minimize the updating overhead during topology change due to mobility of mesh nodes or congestion of load on a cluster. Each cluster contains a gateway that has complete knowledge about group memberships and link state information in the cluster. The gateway is often elected in the cluster formation process. We consider load of gateways and try to reduce it. As a matter of fact when a gateway undertakes to be an interface for connecting nodes of a wireless mesh network to other networks or internet, there would be some problems such as congestion and bottleneck, so we introduce a new paradigm for these problems. For solving bottleneck we use clustering to reduce load of gateways and after that by use of dividing cluster we prevent from bottleneck on gateways. We study how to detect congestion on a gateway and how can reduce loads of it that preventing from bottleneck on gateway and therefore increasing throughput of network to encountering many loads. So we propose an algorithm to detect bottleneck and remedies for load balancing in Wireless Mesh Networks. We also use Ns2-Emultion for implementing and testing the framework. Some qualitative results are provided to prove the correctness and the advantages of our framework.
Defeating jamming with the power of silence a gametheoretic analysisranjith kumar
Dear Student,
DREAMWEB TECHNO SOLUTIONS is one of the Hardware Training and Software Development centre available in
Trichy. Pioneer in corporate training, DREAMWEB TECHNO SOLUTIONS provides training in all software
development and IT-related courses, such as Embedded Systems, VLSI, MATLAB, JAVA, J2EE, CIVIL,
Power Electronics, and Power Systems. It’s certified and experienced faculty members have the
competence to train students, provide consultancy to organizations, and develop strategic
solutions for clients by integrating existing and emerging technologies.
ADD: No:73/5, 3rd Floor, Sri Kamatchi Complex, Opp City Hospital, Salai Road, Trichy-18
Contact @ 7200021403/04
phone: 0431-4050403
The novel applications of sensor networks impose some requirements in wireless sensor network design. With the energy efficiency and lifetime awareness, the throughput and network delayalso required to support emerging applications of sensor networks. In this paper, we propose
throughput and network delay aware intra-cluster routing protocol. We introduce the back-up links in the intra-cluster communication path. The link throughput, communication delay, packet loss ratio, interference, residual energy and node distance are the considered factors in finding efficient path of data communication among the sensor nodes within the cluster. The
simulation result shows the higher throughput and lower average packet delay rate for the proposed routing protocol than the existing benchmarks. The proposed routing protocol also shows energy efficiency and lifetime awareness with better connectivity rate.
The document proposes a clustering-based approach to dynamically allocate bandwidth in wireless networks. It extracts student data from a university's course timetable to predict user distributions over time. It then applies K-means clustering to group buildings into wireless nodes based on expected user loads. This clusters student devices and allows wireless nodes to adapt their bandwidth allocation according to predicted user demands at different times. The approach is tested on a university campus network, extracting student data to predict building loads and applying K-means clustering to allocate optimal bandwidth across wireless nodes over time.
Distance Based Cluster Formation for Enhancing the Network Life Time in ManetsIRJET Journal
This document proposes a distance-based clustering algorithm to improve network lifetime in mobile ad hoc networks (MANETs). The algorithm randomly selects initial cluster heads, then assigns nodes to the closest cluster head based on distance. Simulations in NS-2 and MATLAB analyze energy consumption and residual energy over time. Results show energy use is directly proportional to distance from the cluster head. Nodes near cluster heads conserve more energy, extending network lifetime through load balancing.
MULTI-CLUSTER MULTI-CHANNEL SCHEDULING (MMS) ALGORITHM FOR MAXIMUM DATA COLLE...IJCNCJournal
Interference during data transmission can cause performance degradation like packet collisions in Wireless Sensor Networks (WSNs). While multi-channels available in IEEE 802.15.4 protocol standard WSN technology can be exploited to reduce interference, allocating channel and channel switching
algorithms can have a major impact on the performance of multi-channel communication. This paper presents an improved Fuzzy Logic based Cluster Formation and Cluster Head (CH) Selection algorithm with enhanced network lifetime for multi-cluster topology. The Multi-Cluster Multi-Channel Scheduling
(MMS) algorithm proposed in this paper improves the data collection by minimizing the maximum interference and collision. The presented work has developed Cluster formation and cluster head (CH) selection algorithm and Interference-free data communication by proper channel scheduled. The extensive
simulation and experimental outcomes prove that the proposed algorithm not only provides an interference-free transmission but also provides delay minimization and longevity of the network lifetime, which makes the presented algorithm suitable for energy-constrained wireless sensor networks.
Wireless mesh networks offer high bandwidth Internet access for mobile users anywhere and at any time.
It is an emerging technology that uses wireless multi-hop networking to provide a cost-efficient way for
community or enterprise users to have broadband Internet access and share network resource. In this paper,
we have tried to give a comparative analysis of various Gateway Placement approaches which can be
helpful in understanding which approach will be useful in which situation.
This document summarizes a research paper on clustering schemes for mobile ad hoc networks (MANETs). It discusses some of the key challenges in managing MANETs, including bandwidth and power constraints and dynamic topology. It then reviews several existing clustering algorithms, including those based on connectivity, power awareness, bandwidth adaptation, and minimizing cluster numbers. It proposes a new performance metric and algorithm that uses this metric to ensure all nodes receive optimum performance while maintaining an optimal number of clusters. The performance metric considers both bandwidth available and distance to the cluster head. The algorithm aims to adapt clustering as new nodes join or leave the network.
MULTI-HOP BANDWIDTH MANAGEMENT PROTOCOL FOR MOBILE AD HOC NETWORKSIJMIT JOURNAL
An admission control scheme should play the role of a coordinator for flows in a data communication network, to provide the guarantees as the medium is shared. The nodes of a wired network can monitor the medium to know the available bandwidth at any point of time. But, in wireless ad hoc networks, a node must consume the bandwidth of neighboring nodes, during a communication. Hence, the consumption of bandwidth by a flow and the availability of resources to any wireless node strictly depend upon the neighboring nodes within its transmission range. We present a scalable and efficient admission control scheme, Multi-hop Bandwidth Management Protocol (MBMP), to support the QoS requirements
in multi-hop ad hoc networks. We simulate several options to design MBMP and compare the performances of these options through mathematical analysis and simulation results, and compare its effectiveness with the existing admission control schemes through extensive simulations.
Power Aware Cluster to Minimize Load In Mobile Ad Hoc NetworksIJRES Journal
Mobile ad hoc networks (MANETs) are popularly known to their mobility and ease of usage. These networks are a set of identical nodes that move freely to communicate among networks and they are represented as a set of clusters. However, their wireless and active natures cause them to be more susceptible to various types of security attacks and transmission energy consumption so that they drop out of the network easily. Now-a-days the major challenge of MANETS is to endow with the assurance to the secure network services and also to provide a nearby balance of load for the cluster-heads. To meet this confront, certificate revocation with load balancing is an important central component to provide security and energy conservation in the network communications. In this paper, we focus on load balancing clustering to widen the lifetime of the cluster-head for a maximum time before allowing it to withdraw so as to distribute the responsibility to other legitimate nodes in the cluster to act as a cluster-head along with the issue of certificate revocation process. For quick, accurate, secure certificate revocation and to conserve energy, we propose the CCRV with Load Balancing Clustering scheme where we can reduce the burden of the cluster along with secure certificate revocation. In particular, to minimize the transmission energy consumption, we use the master slave model to operate the network with longer lifetime and we propose load balancing mechanism to enhance the lifetime of the cluster-head.
Distributed Three Hop Routing Protocol for Enhancing Routing Process in WSNpaperpublications3
Abstract: For Hybrid wireless network there is need of efficient data routing protocol for improvement of network capability and scalability. By using Distributed Three Hop routing protocol (DTR), we improve capacity of Hybrid network and Reduce overhead. In early Two- Hop Transmission protocol is used for eliminate route maintenance and limited number of hop in routing for Hybrid Wireless Network but it only considers the node transmission within a single cell while DTR can Also deals with Inter-cell communication in real word. DTR is Top-quality from Other routing Protocol to analyses the hybrid wireless networks with the parametric quantity such as throughput, QoS, packet loss, overhead (due to traffic), channel quality, load balancing, routing delivery, scalability and power consumption. DTR also has a congestion control algorithm to avoid load congestion in base station in the case of unbalanced traffic distributions in networks. DTR makes significantly lower overhead by eliminating route monitoring and maintenance. To enhance the efficiency of routing protocol in wireless network Weight Based Data Assignment technique is used for data allocation in distributed routing protocol using the technique of least delay detection to maintain less data congestion in the network . for that DTR divides a message data stream into segments and transmits the segments in a distributed manner.
Keywords: Data Fragmentation, Responses Delay, Hybrid Wireless Network, Three of Routing Protocol, Fuzzy Logic.
Title: Distributed Three Hop Routing Protocol for Enhancing Routing Process in WSN
Author: Amruta A. Mandhare, Kashmira J. Mayekar, Sayali L. Khanekar, Sarika V.Bodake, Sayali S. Bale.
ISSN 2350-1022
International Journal of Recent Research in Mathematics Computer Science and Information Technology
Paper Publications
This document summarizes the results of a study investigating energy consumption in mobile ad hoc networks (MANETs). It analyzes how varying packet size affects several network performance metrics through simulations. The simulations show that as packet size increases, packet delivery ratio decreases and packet loss ratio increases, due to greater network congestion. Throughput initially increases with packet size but then decreases. Control overhead and average energy consumption both rise with larger packet sizes. Increasing packet size negatively impacts network reliability and energy efficiency. The document concludes that packet size is an important factor influencing the performance of data transmission in MANETs.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Congestion in Wireless Sensor Networks has negative impact on the Quality of Service.
Congestion effects the performance metrics, namely throughput and per-packet energy
consumption, network lifetime and packet delivery ratio. Reducing congestion allows better
utilization of the network resources and thus enhances the Quality of Service metrics of the
network. Traffic Aware Dynamic Routing to Alleviate Congestion in Wireless Sensor Networks
reduces congestion by considering one hop neighbor routing in the network. This paper
proposed an algorithm for Quality of Service Based Traffic-Aware Data forwarding for
congestion control in wireless sensor networks based on two hop neighbor information. On
detection of congestion, the algorithm forwards data packets around the congestion areas by
spreading the excessive packets through multiple paths. The path with light load or under
loaded nodes is efficiently utilized whenever congestion occurs. The main aspect of the
algorithm is to build path to the destination using two independent potential fields depth and
queue length. Queue length field solves the traffic-aware problem. Depth field creates a
backbone to forward packets to the sink. Both fields are combined to yield a hybrid potential
field to make dynamic decision for data forwarding. Network Simulator used for simulating the
algorithm is NS2. The proposed algorithm performs better.
Clustering effects on wireless mobile ad hoc networks performancesijcsit
A new era is dawning for wireless mobile ad hoc networks where communication will be done using a
group of mobile devices called cluster, hence clustered network. In a clustered network, protocols used by
these mobile devices are different from those used in a wired network; which helps to save computation
time and resources efficiently. This paper focuses on Cluster-Based Routing Protocol and Dynamic Source
Routing. The results presented in this paper illustrates the implementation of Ad-hoc On-Demand Distance
Vector routing protocol for enhancing mobile nodes performance and lifetime in a clustered network and to
demonstrate how this routing protocol results in time efficient and resource saving in wireless mobile ad
hoc networks.
Dear Student,
DREAMWEB TECHNO SOLUTIONS is one of the Hardware Training and Software Development centre available in
Trichy. Pioneer in corporate training, DREAMWEB TECHNO SOLUTIONS provides training in all software
development and IT-related courses, such as Embedded Systems, VLSI, MATLAB, JAVA, J2EE, CIVIL,
Power Electronics, and Power Systems. It’s certified and experienced faculty members have the
competence to train students, provide consultancy to organizations, and develop strategic
solutions for clients by integrating existing and emerging technologies.
ADD: No:73/5, 3rd Floor, Sri Kamatchi Complex, Opp City Hospital, Salai Road, Trichy-18
Contact @ 7200021403/04
phone: 0431-4050403
An Adaptive Cluster Head Election Algorithm for Heterogeneous Mobile Ad-hoc N...IJLT EMAS
This document proposes an adaptive cluster head election algorithm for heterogeneous mobile ad-hoc networks. It begins by discussing how mobile ad-hoc networks can be homogeneous or heterogeneous based on node capabilities. The effects of heterogeneity, including issues with coverage area, link stability and lifetime, are analyzed. An algorithm is then suggested that considers node mobility, power and transmission range to adaptively elect cluster heads in heterogeneous networks. The proposed algorithm is simulated and evaluated based on parameters like cluster formation overhead and cluster lifetime under different transmission ranges. The results show the algorithm can help ensure stable cluster formations and address issues caused by node heterogeneity in mobile ad-hoc networks.
A Survey Paper on Cluster Head Selection Techniques for Mobile Ad-Hoc NetworkIOSR Journals
This document summarizes several cluster head selection techniques for mobile ad-hoc networks (MANETs). It discusses techniques that select the cluster head based on attributes like node ID, degree of connectivity, mobility, load balancing, and power consumption. Some techniques aim to improve stability and reduce overhead by minimizing cluster changes. Each technique has advantages like simplicity or load balancing, and disadvantages like additional messaging or inability to eliminate ties between nodes. The survey provides a comparison of the techniques on their selection criteria and merits and demerits.
QoS controlled capacity offload optimization in heterogeneous networksjournalBEEI
An efficient resource allocation mechanism in the physical layer of wireless networks ensures that resources such as bandwidth and power are used with high efficiency in spite of low delay and high edge user data rate. Microcells in the network are typically set with bias settings to artificially increase the Signal-to-Interference-Plus-Noise Ratio, thus encouraging users to offload to the microcell. However, the artificial bias settings are tedious and often suboptimal. This work presents a low complexity algorithm for maximization of network capacity with load balancing in a heterogeneous network without the need for bias setting. The small cells were deployed in a grid topology at a selected distance from macrocell to enhance network capacity through coverage overlap. User association and minimum user throughput were incorporated as constraints to enable closer simulation to real word Quality of Service requirements. The results showed that the proposed algorithm was able to maintain less than 10% user drop rate. The proposed algorithm can increase user confidence as well as maintain load balancing, maintain the scalability, and reduce power consumption of the wireless network.
Dear Student,
DREAMWEB TECHNO SOLUTIONS is one of the Hardware Training and Software Development centre available in
Trichy. Pioneer in corporate training, DREAMWEB TECHNO SOLUTIONS provides training in all software
development and IT-related courses, such as Embedded Systems, VLSI, MATLAB, JAVA, J2EE, CIVIL,
Power Electronics, and Power Systems. It’s certified and experienced faculty members have the
competence to train students, provide consultancy to organizations, and develop strategic
solutions for clients by integrating existing and emerging technologies.
ADD: No:73/5, 3rd Floor, Sri Kamatchi Complex, Opp City Hospital, Salai Road, Trichy-18
Contact @ 7200021403/04
phone: 0431-4050403
Analysing Mobile Random Early Detection for Congestion Control in Mobile Ad-h...IJECEIAES
This research paper suggests and analyse a technique for congestion control in mobile ad hoc networks. The technique is based on a new hybrid approach that uses clustering and queuing techniques. In clustering, in general cluster head transfers the data, following a queuing method based on a RED (Random Early Detection), the mobile environment makes it Mobile RED (or MRED), It majorly depends upon mobility of nodes and mobile environments leads to unpredictable queue size. To simulate this technique, the Network Simulator 2 (or NS2) is used for various scenarios. The simulated results are compared with NRED (Neighbourhood Random Early Detection) queuing technique of congestion control. It has been observed that the results are improved using MRED comparatively.
IMPROVING PACKET DELIVERY RATIO WITH ENHANCED CONFIDENTIALITY IN MANETijcsa
In Mobile Ad Hoc Network (MANET), the collection of mobile nodes gets communicated without the need of any customary infrastructure. In MANET, repeated topology changes and intermittent link breakage
causes the failure of existing path. This leads to rediscovery of new route by broadcasting RREQ packet.The number of RREQ packet in the network gets added due to the increased amount of link failures. This result in increased routing overhead which degrades the packet delivery ratio in MANET. While designing
routing protocols for MANET, it is indispensable to reduce the overhead in route discovery. In our previous
work[17], routing protocol based on neighbour details and probabilistic knowledge is utilized, additionally
the symmetric cipher AES is used for securing the data packet. Through this protocol, packet delivery ratio
gets increased and confidentiality is ensured. But there is a problem in secure key exchange among the
source and destination while using AES. To resolve that problem, hybrid cryptographic system i.e.,
combination of AES and RSA is proposed in this paper. By using this hybrid cryptographic scheme and the
routing protocol based on probability and neighbour knowledge, enhanced secure packet delivery is
ensured in MANET
Algorithmic Construction of Optimal and Load Balanced Clusters in Wireless Se...M H
This paper proposes a clustering algorithm - Ba-lanced Minimum Radius Clustering (BMRC) - for use in large scale, distributed Wireless Sensor Networks (WSN). Cluster balancing is an intractable problem to solve in a distributed manner, and distribution is important, by reason of both avoiding specialised node vulnerability and minimising message overhead.The BMRC algorithm described here distributes several of the cluster balancing functions to the cluster-heads. In proposing this algorithm, several tentative claims have been made for it, namely that it is suitable for arbitrary number of cluster heads; that its pecifies a way to elect cluster heads and use them to create the local models; that it accomplishes optimal balanced clusters in distributed manner; that it is scalable and it uses the number-of-hops as a clustering parameter; that it is energy efficient. These claims were studied and verified by simulation.
Congestion is said to occur in the network when the resource demands exceed the capacity and packets are lost due to too much queuing in the network. During congestion, the network throughput may drop to zero and the path delay may become very high. A congestion control scheme helps the network to recover from the congestion state. In fact, security plays a vital role in Wireless Ad hoc network. This paper presents a systematic literature review to provide comprehensive and unbiased information about various current model Congestion Control conceptions, proposals, problems and solutions in Ad hoc for safety transportation. For this purpose, a total of 33 articles related to the security model in Congestion Control published between 2008 and 2013 were extracted from the most relevant scientific sources (IEEE Computer Society, ACM Digital Library, Springer Link and Science Direct). However, 18 articles were eventually analyzed due to several reasons such as relevancy and comprehensiveness of discussion presented in the articles. Using the systematic method of review, this paper succeeds to reveal the main security threats and Error control, challenges for security, security requirement in Congestion Control in Wireless Ad hoc network (CCWAN) and future research within this scope.
Improving the network lifetime of mane ts through cooperative mac protocol de...Pvrtechnologies Nellore
The document proposes a novel cooperative MAC (CMAC) protocol called DEL-CMAC for improving the network lifetime of mobile ad hoc networks (MANETs). DEL-CMAC incorporates a distributed utility-based best relay selection strategy based on location information and residual energy. It also includes a cross-layer optimal transmitting power allocation scheme to conserve energy while maintaining throughput. Additionally, it provides an innovative network allocation vector setting to deal with interference from varying transmitting powers during cooperation. Simulation results show DEL-CMAC significantly prolongs network lifetime under different scenarios compared to the IEEE 802.11 standard and other throughput-focused CMAC protocols.
Balancing stable topology and network lifetime in ad hoc networksIAEME Publication
This document summarizes a research paper that proposes a new topology control method called Network Connectivity based Topology Control (NCTC) to improve network lifetime in mobile ad hoc networks. The method aims to balance energy consumption and node connectivity in two phases: 1) minimizing interference between links, and 2) estimating an energy-efficient topology based on minimal weight paths. Simulation results using the NS2 simulator show that NCTC achieves better network lifetime, packet delivery ratio, lower overhead, and end-to-end delay compared to existing methods.
Los especialistas recomiendan comer adecuadamente con frutas y vegetales, tomar vitaminas como la C, hacer ejercicio y caminar al menos 30 minutos diarios, lavarse las manos a menudo y tomar aire fresco para evitar enfermarse. El documento luego sugiere mantener altos niveles de alcohol para mantener alejados los gérmenes, aunque esto claramente no es un consejo médico válido.
The document discusses the North East Better Health at Work Award (BHAWA), which recognizes employers that address health issues in the workplace. The award is free and open to all employers in the region. It has 4 levels - Bronze, Silver, Gold, and Continuing Excellence - with criteria at each level to build a portfolio. Over 400 employers have participated, including large companies. The award helps employers promote physical and mental health, reduce absenteeism, and create a healthier workplace culture.
The document provides information about resume samples, cover letters, interview questions, and other resources for housing inspectors. It lists top resume types including chronological, functional, curriculum vitae, combination, targeted, professional, new graduate, and executive resumes. It also provides links to additional materials on resume writing, cover letters, interview preparation, and sample interview questions for housing inspector roles.
This document summarizes a research paper on clustering schemes for mobile ad hoc networks (MANETs). It discusses some of the key challenges in managing MANETs, including bandwidth and power constraints and dynamic topology. It then reviews several existing clustering algorithms, including those based on connectivity, power awareness, bandwidth adaptation, and minimizing cluster numbers. It proposes a new performance metric and algorithm that uses this metric to ensure all nodes receive optimum performance while maintaining an optimal number of clusters. The performance metric considers both bandwidth available and distance to the cluster head. The algorithm aims to adapt clustering as new nodes join or leave the network.
MULTI-HOP BANDWIDTH MANAGEMENT PROTOCOL FOR MOBILE AD HOC NETWORKSIJMIT JOURNAL
An admission control scheme should play the role of a coordinator for flows in a data communication network, to provide the guarantees as the medium is shared. The nodes of a wired network can monitor the medium to know the available bandwidth at any point of time. But, in wireless ad hoc networks, a node must consume the bandwidth of neighboring nodes, during a communication. Hence, the consumption of bandwidth by a flow and the availability of resources to any wireless node strictly depend upon the neighboring nodes within its transmission range. We present a scalable and efficient admission control scheme, Multi-hop Bandwidth Management Protocol (MBMP), to support the QoS requirements
in multi-hop ad hoc networks. We simulate several options to design MBMP and compare the performances of these options through mathematical analysis and simulation results, and compare its effectiveness with the existing admission control schemes through extensive simulations.
Power Aware Cluster to Minimize Load In Mobile Ad Hoc NetworksIJRES Journal
Mobile ad hoc networks (MANETs) are popularly known to their mobility and ease of usage. These networks are a set of identical nodes that move freely to communicate among networks and they are represented as a set of clusters. However, their wireless and active natures cause them to be more susceptible to various types of security attacks and transmission energy consumption so that they drop out of the network easily. Now-a-days the major challenge of MANETS is to endow with the assurance to the secure network services and also to provide a nearby balance of load for the cluster-heads. To meet this confront, certificate revocation with load balancing is an important central component to provide security and energy conservation in the network communications. In this paper, we focus on load balancing clustering to widen the lifetime of the cluster-head for a maximum time before allowing it to withdraw so as to distribute the responsibility to other legitimate nodes in the cluster to act as a cluster-head along with the issue of certificate revocation process. For quick, accurate, secure certificate revocation and to conserve energy, we propose the CCRV with Load Balancing Clustering scheme where we can reduce the burden of the cluster along with secure certificate revocation. In particular, to minimize the transmission energy consumption, we use the master slave model to operate the network with longer lifetime and we propose load balancing mechanism to enhance the lifetime of the cluster-head.
Distributed Three Hop Routing Protocol for Enhancing Routing Process in WSNpaperpublications3
Abstract: For Hybrid wireless network there is need of efficient data routing protocol for improvement of network capability and scalability. By using Distributed Three Hop routing protocol (DTR), we improve capacity of Hybrid network and Reduce overhead. In early Two- Hop Transmission protocol is used for eliminate route maintenance and limited number of hop in routing for Hybrid Wireless Network but it only considers the node transmission within a single cell while DTR can Also deals with Inter-cell communication in real word. DTR is Top-quality from Other routing Protocol to analyses the hybrid wireless networks with the parametric quantity such as throughput, QoS, packet loss, overhead (due to traffic), channel quality, load balancing, routing delivery, scalability and power consumption. DTR also has a congestion control algorithm to avoid load congestion in base station in the case of unbalanced traffic distributions in networks. DTR makes significantly lower overhead by eliminating route monitoring and maintenance. To enhance the efficiency of routing protocol in wireless network Weight Based Data Assignment technique is used for data allocation in distributed routing protocol using the technique of least delay detection to maintain less data congestion in the network . for that DTR divides a message data stream into segments and transmits the segments in a distributed manner.
Keywords: Data Fragmentation, Responses Delay, Hybrid Wireless Network, Three of Routing Protocol, Fuzzy Logic.
Title: Distributed Three Hop Routing Protocol for Enhancing Routing Process in WSN
Author: Amruta A. Mandhare, Kashmira J. Mayekar, Sayali L. Khanekar, Sarika V.Bodake, Sayali S. Bale.
ISSN 2350-1022
International Journal of Recent Research in Mathematics Computer Science and Information Technology
Paper Publications
This document summarizes the results of a study investigating energy consumption in mobile ad hoc networks (MANETs). It analyzes how varying packet size affects several network performance metrics through simulations. The simulations show that as packet size increases, packet delivery ratio decreases and packet loss ratio increases, due to greater network congestion. Throughput initially increases with packet size but then decreases. Control overhead and average energy consumption both rise with larger packet sizes. Increasing packet size negatively impacts network reliability and energy efficiency. The document concludes that packet size is an important factor influencing the performance of data transmission in MANETs.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Congestion in Wireless Sensor Networks has negative impact on the Quality of Service.
Congestion effects the performance metrics, namely throughput and per-packet energy
consumption, network lifetime and packet delivery ratio. Reducing congestion allows better
utilization of the network resources and thus enhances the Quality of Service metrics of the
network. Traffic Aware Dynamic Routing to Alleviate Congestion in Wireless Sensor Networks
reduces congestion by considering one hop neighbor routing in the network. This paper
proposed an algorithm for Quality of Service Based Traffic-Aware Data forwarding for
congestion control in wireless sensor networks based on two hop neighbor information. On
detection of congestion, the algorithm forwards data packets around the congestion areas by
spreading the excessive packets through multiple paths. The path with light load or under
loaded nodes is efficiently utilized whenever congestion occurs. The main aspect of the
algorithm is to build path to the destination using two independent potential fields depth and
queue length. Queue length field solves the traffic-aware problem. Depth field creates a
backbone to forward packets to the sink. Both fields are combined to yield a hybrid potential
field to make dynamic decision for data forwarding. Network Simulator used for simulating the
algorithm is NS2. The proposed algorithm performs better.
Clustering effects on wireless mobile ad hoc networks performancesijcsit
A new era is dawning for wireless mobile ad hoc networks where communication will be done using a
group of mobile devices called cluster, hence clustered network. In a clustered network, protocols used by
these mobile devices are different from those used in a wired network; which helps to save computation
time and resources efficiently. This paper focuses on Cluster-Based Routing Protocol and Dynamic Source
Routing. The results presented in this paper illustrates the implementation of Ad-hoc On-Demand Distance
Vector routing protocol for enhancing mobile nodes performance and lifetime in a clustered network and to
demonstrate how this routing protocol results in time efficient and resource saving in wireless mobile ad
hoc networks.
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An Adaptive Cluster Head Election Algorithm for Heterogeneous Mobile Ad-hoc N...IJLT EMAS
This document proposes an adaptive cluster head election algorithm for heterogeneous mobile ad-hoc networks. It begins by discussing how mobile ad-hoc networks can be homogeneous or heterogeneous based on node capabilities. The effects of heterogeneity, including issues with coverage area, link stability and lifetime, are analyzed. An algorithm is then suggested that considers node mobility, power and transmission range to adaptively elect cluster heads in heterogeneous networks. The proposed algorithm is simulated and evaluated based on parameters like cluster formation overhead and cluster lifetime under different transmission ranges. The results show the algorithm can help ensure stable cluster formations and address issues caused by node heterogeneity in mobile ad-hoc networks.
A Survey Paper on Cluster Head Selection Techniques for Mobile Ad-Hoc NetworkIOSR Journals
This document summarizes several cluster head selection techniques for mobile ad-hoc networks (MANETs). It discusses techniques that select the cluster head based on attributes like node ID, degree of connectivity, mobility, load balancing, and power consumption. Some techniques aim to improve stability and reduce overhead by minimizing cluster changes. Each technique has advantages like simplicity or load balancing, and disadvantages like additional messaging or inability to eliminate ties between nodes. The survey provides a comparison of the techniques on their selection criteria and merits and demerits.
QoS controlled capacity offload optimization in heterogeneous networksjournalBEEI
An efficient resource allocation mechanism in the physical layer of wireless networks ensures that resources such as bandwidth and power are used with high efficiency in spite of low delay and high edge user data rate. Microcells in the network are typically set with bias settings to artificially increase the Signal-to-Interference-Plus-Noise Ratio, thus encouraging users to offload to the microcell. However, the artificial bias settings are tedious and often suboptimal. This work presents a low complexity algorithm for maximization of network capacity with load balancing in a heterogeneous network without the need for bias setting. The small cells were deployed in a grid topology at a selected distance from macrocell to enhance network capacity through coverage overlap. User association and minimum user throughput were incorporated as constraints to enable closer simulation to real word Quality of Service requirements. The results showed that the proposed algorithm was able to maintain less than 10% user drop rate. The proposed algorithm can increase user confidence as well as maintain load balancing, maintain the scalability, and reduce power consumption of the wireless network.
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Trichy. Pioneer in corporate training, DREAMWEB TECHNO SOLUTIONS provides training in all software
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Power Electronics, and Power Systems. It’s certified and experienced faculty members have the
competence to train students, provide consultancy to organizations, and develop strategic
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Analysing Mobile Random Early Detection for Congestion Control in Mobile Ad-h...IJECEIAES
This research paper suggests and analyse a technique for congestion control in mobile ad hoc networks. The technique is based on a new hybrid approach that uses clustering and queuing techniques. In clustering, in general cluster head transfers the data, following a queuing method based on a RED (Random Early Detection), the mobile environment makes it Mobile RED (or MRED), It majorly depends upon mobility of nodes and mobile environments leads to unpredictable queue size. To simulate this technique, the Network Simulator 2 (or NS2) is used for various scenarios. The simulated results are compared with NRED (Neighbourhood Random Early Detection) queuing technique of congestion control. It has been observed that the results are improved using MRED comparatively.
IMPROVING PACKET DELIVERY RATIO WITH ENHANCED CONFIDENTIALITY IN MANETijcsa
In Mobile Ad Hoc Network (MANET), the collection of mobile nodes gets communicated without the need of any customary infrastructure. In MANET, repeated topology changes and intermittent link breakage
causes the failure of existing path. This leads to rediscovery of new route by broadcasting RREQ packet.The number of RREQ packet in the network gets added due to the increased amount of link failures. This result in increased routing overhead which degrades the packet delivery ratio in MANET. While designing
routing protocols for MANET, it is indispensable to reduce the overhead in route discovery. In our previous
work[17], routing protocol based on neighbour details and probabilistic knowledge is utilized, additionally
the symmetric cipher AES is used for securing the data packet. Through this protocol, packet delivery ratio
gets increased and confidentiality is ensured. But there is a problem in secure key exchange among the
source and destination while using AES. To resolve that problem, hybrid cryptographic system i.e.,
combination of AES and RSA is proposed in this paper. By using this hybrid cryptographic scheme and the
routing protocol based on probability and neighbour knowledge, enhanced secure packet delivery is
ensured in MANET
Algorithmic Construction of Optimal and Load Balanced Clusters in Wireless Se...M H
This paper proposes a clustering algorithm - Ba-lanced Minimum Radius Clustering (BMRC) - for use in large scale, distributed Wireless Sensor Networks (WSN). Cluster balancing is an intractable problem to solve in a distributed manner, and distribution is important, by reason of both avoiding specialised node vulnerability and minimising message overhead.The BMRC algorithm described here distributes several of the cluster balancing functions to the cluster-heads. In proposing this algorithm, several tentative claims have been made for it, namely that it is suitable for arbitrary number of cluster heads; that its pecifies a way to elect cluster heads and use them to create the local models; that it accomplishes optimal balanced clusters in distributed manner; that it is scalable and it uses the number-of-hops as a clustering parameter; that it is energy efficient. These claims were studied and verified by simulation.
Congestion is said to occur in the network when the resource demands exceed the capacity and packets are lost due to too much queuing in the network. During congestion, the network throughput may drop to zero and the path delay may become very high. A congestion control scheme helps the network to recover from the congestion state. In fact, security plays a vital role in Wireless Ad hoc network. This paper presents a systematic literature review to provide comprehensive and unbiased information about various current model Congestion Control conceptions, proposals, problems and solutions in Ad hoc for safety transportation. For this purpose, a total of 33 articles related to the security model in Congestion Control published between 2008 and 2013 were extracted from the most relevant scientific sources (IEEE Computer Society, ACM Digital Library, Springer Link and Science Direct). However, 18 articles were eventually analyzed due to several reasons such as relevancy and comprehensiveness of discussion presented in the articles. Using the systematic method of review, this paper succeeds to reveal the main security threats and Error control, challenges for security, security requirement in Congestion Control in Wireless Ad hoc network (CCWAN) and future research within this scope.
Improving the network lifetime of mane ts through cooperative mac protocol de...Pvrtechnologies Nellore
The document proposes a novel cooperative MAC (CMAC) protocol called DEL-CMAC for improving the network lifetime of mobile ad hoc networks (MANETs). DEL-CMAC incorporates a distributed utility-based best relay selection strategy based on location information and residual energy. It also includes a cross-layer optimal transmitting power allocation scheme to conserve energy while maintaining throughput. Additionally, it provides an innovative network allocation vector setting to deal with interference from varying transmitting powers during cooperation. Simulation results show DEL-CMAC significantly prolongs network lifetime under different scenarios compared to the IEEE 802.11 standard and other throughput-focused CMAC protocols.
Balancing stable topology and network lifetime in ad hoc networksIAEME Publication
This document summarizes a research paper that proposes a new topology control method called Network Connectivity based Topology Control (NCTC) to improve network lifetime in mobile ad hoc networks. The method aims to balance energy consumption and node connectivity in two phases: 1) minimizing interference between links, and 2) estimating an energy-efficient topology based on minimal weight paths. Simulation results using the NS2 simulator show that NCTC achieves better network lifetime, packet delivery ratio, lower overhead, and end-to-end delay compared to existing methods.
Los especialistas recomiendan comer adecuadamente con frutas y vegetales, tomar vitaminas como la C, hacer ejercicio y caminar al menos 30 minutos diarios, lavarse las manos a menudo y tomar aire fresco para evitar enfermarse. El documento luego sugiere mantener altos niveles de alcohol para mantener alejados los gérmenes, aunque esto claramente no es un consejo médico válido.
The document discusses the North East Better Health at Work Award (BHAWA), which recognizes employers that address health issues in the workplace. The award is free and open to all employers in the region. It has 4 levels - Bronze, Silver, Gold, and Continuing Excellence - with criteria at each level to build a portfolio. Over 400 employers have participated, including large companies. The award helps employers promote physical and mental health, reduce absenteeism, and create a healthier workplace culture.
The document provides information about resume samples, cover letters, interview questions, and other resources for housing inspectors. It lists top resume types including chronological, functional, curriculum vitae, combination, targeted, professional, new graduate, and executive resumes. It also provides links to additional materials on resume writing, cover letters, interview preparation, and sample interview questions for housing inspector roles.
The document outlines the sustainable practices used at a conference including using BPA-free corn plastic for mugs, recycled materials for bags, donating leftover materials to non-profits, using soy ink and recycled paper for program books, recycled trade show carpet, re-using table skirts and pipe and drape, lowering light and heat during setup and takedown, making signage reusable, using recycled foam core, encouraging a digital conference with no paper handouts, a digital press kit needing no paper, donating leftover books to Better World Books, and encouraging sustainable practices for all attendees through a Green Pledge.
This document discusses mobile client application solutions for mobile operators. It provides contact information for a company located in Rome, Italy that offers these solutions. The document expresses gratitude at the end.
This document provides guidance on lead generation and account management processes for TATA Tele Services sales representatives. It outlines steps for capturing lead information, checking if an account already exists and requesting account creation if needed, sharing or transferring accounts, verifying account details, creating sales opportunities, conducting feasibility assessments for connectivity, and generating service proposals with pricing quotes. The objective is to effectively propose enterprise solutions and generate quality sales leads that can be pursued.
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Met behulp van de koppelingenbibliotheek in SCIA Engineer definëert men met één enkele muisklik de Layher steigerkoppelingen. Controles worden uitgevoerd conform EN12810 en EN12811
This document provides 4 links to technical papers related to wireless sensor networks. The papers discuss topics such as secure data distribution in wireless sensor networks, optimizing watchdog systems for more energy efficient trust systems, using game theory to analyze defeating jamming attacks through strategic use of silence, and the design of a cost-aware secure routing protocol for wireless sensor networks called CASER.
This document is a resume for Alyssa M Amabile. It outlines her education, including a BA in Anthropology from San Francisco State University and an AA in Liberal Arts from Cuesta College. Her professional experience includes roles as a Project Coordinator at NanaWall Systems, a Marketing Coordinator and Server at Espana's Southwest Bar & Grill, a Personal Banker and Customer Service Representative at Wells Fargo, and a Student Research Assistant at San Francisco State University. She has strong analytical, organizational and project management skills.
Los especialistas recomiendan comer adecuadamente con frutas y vegetales, tomar vitaminas como la C, hacer ejercicio y caminar al menos 30 minutos diarios, lavarse las manos con frecuencia y tomar aire fresco para evitar enfermarse. El documento luego sugiere de manera humorística que mantener altos niveles de alcohol mata los gérmenes y previene enfermedades.
This document provides an overview of Sicily, describing its history of invasions and rulers from ancient times to the 19th century. It highlights key cities like Palermo, Monreale, Agrigento, Taormina, and Siracusa, noting their important historical and architectural sites. Photos show the natural beauty and agricultural products of Sicily, along with its cathedrals, temples, and other cultural attractions.
Top 8 informatics pharmacist resume samplesWonderGirls345
The document provides resources for informatics pharmacist interviews and resumes, including sample resumes of different formats (chronological, functional, combination, CV), interview questions, tips for writing effective resumes and preparing for interviews, and related career fields. The resources are from the website resume123.org and cover resumes, cover letters, interview preparation, and career development.
Site Investigation For Offshorewind Version 1 Oi 10 Rev 1mattijsdelange
This document discusses the multi-disciplinary approach to engineering and site investigations for offshore wind farms. It outlines the key steps in choosing a location, designing the layout, choosing the support structure, conducting preliminary site assessments, carrying out detailed site investigations including geophysical and geotechnical surveys, integrating the collected data, and using this information for final foundation design and installation. The presentation acknowledges contributions from several organizations and individuals and concludes by inviting questions.
Why service (design)? - The Developer's ConferenceIsrael Lessak
O documento discute como o design pode contribuir para a inovação em negócios ao contrastar as lógicas dominantes de bens e serviços e propor uma lógica dominante de serviço. Também descreve como o pensamento de design de serviço é abstrato e concreto, cocriativo e centrado no ser humano.
Dynamic Topology Re-Configuration in Multihop Cellular Networks Using Sequent...IJERA Editor
Cellular communications has experienced explosive growth in the past two decades. Today millions of people around the world use cellular phones. Cellular phones allow a person to make or receive a call from almost anywhere. Likewise, a person is allowed to continue the phone conversation while on the move. Cellular communications is supported by an infrastructure called a cellular network, which integrates cellular phones into the public switched telephone network. The cellular network has gone through three generations.The first generation of cellular networks is analog in nature. To accommodate more cellular phone subscribers, digital TDMA (time division multiple access) and CDMA (code division multiple access) technologies are used in the second generation (2G) to increase the network capacity. With digital technologies, digitized voice can be coded and encrypted. Therefore, the 2G cellular network is also more secure. The third generation (3G) integrates cellular phones into the Internet world by providing highspeed packet-switching data transmission in addition to circuit-switching voice transmission. The 3G cellular networks have been deployed in some parts of Asia, Europe, and the United States since 2002 and will be widely deployed in the coming years. The high increase in traffic and data rate for future generations of mobile communication systems, with simultaneous requirement for reduced power consumption, makes Multihop Cellular Networks (MCNs) an attractive technology. To exploit the potentials of MCNs a new network paradigm is proposed in this paper. In addition, a novel sequential genetic algorithm (SGA) is proposed as a heuristic approximation to reconfigure the optimum relaying topology as the network traffic changes. Network coding is used to combine the uplink and downlink transmissions, and incorporate it into the optimum bidirectional relaying with ICI awareness. Numerical results have shown that the algorithms suggested in this thesis provide significant improvement with respect to the existing results, and are expected to have significant impact in the analysis and design of future cellular networks.
TTACCA: TWO-HOP BASED TRAFFIC AWARE CONGESTION CONTROL ALGORITHM FOR WIRELESS...cscpconf
Congestion in Wireless Sensor Networks has negative impact on the Quality of Service.
Congestion effects the performance metrics, namely throughput and per-packet energy
consumption, network lifetime and packet delivery ratio. Reducing congestion allows better
utilization of the network resources and thus enhances the Quality of Service metrics of the
network. Traffic Aware Dynamic Routing to Alleviate Congestion in Wireless Sensor Networks
reduces congestion by considering one hop neighbor routing in the network. This paper
proposed an algorithm for Quality of Service Based Traffic-Aware Data forwarding for
congestion control in wireless sensor networks based on two hop neighbor information. On
detection of congestion, the algorithm forwards data packets around the congestion areas by
spreading the excessive packets through multiple paths. The path with light load or under
loaded nodes is efficiently utilized whenever congestion occurs. The main aspect of the
algorithm is to build path to the destination using two independent potential fields depth and
queue length. Queue length field solves the traffic-aware problem. Depth field creates a
backbone to forward packets to the sink. Both fields are combined to yield a hybrid potential
field to make dynamic decision for data forwarding. Network Simulator used for simulating the
algorithm is NS2. The proposed algorithm performs better.
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Optical network is an emerging technology for data communication
inworldwide. The information is transmitted from the source to destination
through the fiber optics. All optical network (AON) provides good
transmission transparency, good expandability, large bandwidth, lower bit
error rate (BER), and high processing speed. Link failure and node failure
haveconsistently occurred in the traditional methods. In order to overcome
the above mentioned issues, this paper proposes a robust software defined
switching enabled fault localization framework (SDSFLF) to monitor the
node and link failure in an AON. In this work, a novel faulty node
localization (FNL) algorithm is exploited to locate the faulty node. Then, the
software defined faulty link detection (SDFLD) algorithm that addresses the
problem of link failure. The failures are localized in multi traffic stream
(MTS) and multi agent system (MAS). Thus, the throughput is improved in
SDSFLF compared than other existing methods like traditional routing and
wavelength assignment (RWA), simulated annealing (SA) algorithm, attackaware RWA (A-RWA) convex, longest path first (LPF) ordering, and
biggest source-destination node degree (BND) ordering. The performance of
the proposed algorithm is evaluated in terms of network load, wavelength
utilization, packet loss rate, and burst loss rate. Hence, proposed SDSFLF
assures that high performance is achieved than other traditional techniques.
Mobile Agents based Energy Efficient Routing for Wireless Sensor NetworksEswar Publications
Energy Efficiency and prolonged network lifetime are few of the major concern areas. Energy consumption rated of sensor nodes can be reduced in various ways. Data aggregation, result sharing and filtration of aggregated data among sensor nodes deployed in the unattended regions have been few of the most researched areas in the field of wireless sensor networks. While data aggregation is concerned with minimizing the information transfer from source to sink to reduce network traffic and removing congestion in network, result sharing focuses on sharing of information among agents pertinent to the tasks at hand and filtration of aggregated data so as to remove redundant information. There exist various algorithms for data aggregation and filtration using different mobile agents. In this proposed work same mobile agent is used to perform both tasks data aggregation and data filtration. This approach advocates the sharing of resources and reducing the energy consumption level of sensor nodes.
CFMS: A CLUSTER-BASED CONVERGECAST FRAMEWORK FOR DENSE MULTI-SINK WIRELESS SE...ijwmn
Convergecast is one of the most challenging tasks in Wireless Sensor Networks (WSNs). Indeed, this data
collection process must be conducted while copying with packet collisions, nodes’ congestion or data
redundancy. These issues always result in energy waste which is detrimental to network efficiency and
lifetime. This paper is aimed to address these problems in large-scale multi-sink WSNs. Inspired by our
previous work MSCP, we designed a lightweight protocol stack that seamlessly combines clustering, pathvector routing, sinks’ duty cycling, data aggregation and transmission scheduling in order to minimise
message overhead and packet losses. Simulation results show that this solution can mitigate delay while
significantly increasing packet delivery and network lifetime.
CFMS: A Cluster-based Convergecast Framework for Dense Multi-Sink Wireless Se...ijwmn
Convergecast is one of the most challenging tasks in Wireless Sensor Networks (WSNs). Indeed, this data
collection process must be conducted while copying with packet collisions, nodes’ congestion or data
redundancy. These issues always result in energy waste which is detrimental to network efficiency and
lifetime. This paper is aimed to address these problems in large-scale multi-sink WSNs. Inspired by our
previous work MSCP, we designed a lightweight protocol stack that seamlessly combines clustering, pathvector routing, sinks’ duty cycling, data aggregation and transmission scheduling in order to minimise
message overhead and packet losses. Simulation results show that this solution can mitigate delay while
significantly increasing packet delivery and network lifetime.
CFMS: A CLUSTER-BASED CONVERGECAST FRAMEWORK FOR DENSE MULTI-SINK WIRELESS SE...ijwmn
Convergecast is one of the most challenging tasks in Wireless Sensor Networks (WSNs). Indeed, this data
collection process must be conducted while copying with packet collisions, nodes’ congestion or data
redundancy. These issues always result in energy waste which is detrimental to network efficiency and
lifetime. This paper is aimed to address these problems in large-scale multi-sink WSNs. Inspired by our
previous work MSCP, we designed a lightweight protocol stack that seamlessly combines clustering, pathvector routing, sinks’ duty cycling, data aggregation and transmission scheduling in order to minimise
message overhead and packet losses. Simulation results show that this solution can mitigate delay while
significantly increasing packet delivery and network lifetime.
Analysis of Neighbor Knowledge Based Bcast Protocol Performance For Multihop ...pijans
Reliable group communication is a challenging issue for most Mobile Ad-hoc Networks (MANETs) due to
dynamic nature of wireless mobile nodes, group key establishment and management, ensuring secure
information exchange and Quality of Service (QoS) in data transfer. Recently multicast and broadcast
routing protocols are emerging for supporting QoS aware group communication. In MANETs QoS
requirements can be quantified by a set of measurable pre-specified service attributes such as packet
delivery ratio, end-to-end delay, packet loss probability, network control overhead, throughput,
bandwidth, power consumption, service coverage area etc. In this paper, the performance of a neighbor
knowledge based broadcast protocol is analyzed using different QoS metrics (packet delivery ratio, end-toend delay, packet loss probability and network control overhead). BCAST is used as broadcast protocol.
The performance differentials are analyzed using NS-2 network simulator for varying number of data
senders (multicast group size) and data sending rate (offered traffic to the network) over QoS aware group
communication. Simulation results show that BCAST performs well in most cases and provides robust
performance even with high traffic environments.
Analysis of Neighbor Knowledge Based Bcast Protocol Performance For Multihop ...pijans
This document analyzes the performance of a neighbor knowledge based broadcast protocol called BCAST in mobile ad hoc networks using network simulator NS-2. It varies the number of data senders (multicast group size) and data sending rate to analyze packet delivery ratio, end-to-end delay, packet loss probability, and network control overhead. The simulation results show that BCAST generally performs well and provides robust performance even with high traffic loads.
CPCRT: Crosslayered and Power Conserved Routing Topology for congestion Cont...IOSR Journals
The document describes a proposed Crosslayered and Power Conserved Routing Topology (CPCRT) for congestion control in mobile ad hoc networks. The CPCRT aims to improve transmission performance by distinguishing between packet loss due to link failure versus other causes, while also conserving power used for packet transmission. It builds upon an earlier Crosslayered Routing Topology (CRT) approach by incorporating power conservation. The CPCRT is intended to identify the root cause of packet loss, avoid unnecessary congestion handling from link failures, allow congestion handling at specific high-traffic nodes rather than all nodes, and optimize resource and power usage for packet routing in mobile ad hoc networks.
INTERFERENCE-AWARE CHANNEL ASSIGNMENT FOR MAXIMIZING THROUGHPUT IN WMN pijans
Wireless Mesh network (WMN) is dynamically self-organizing and self-configured, with the nodes in the
network automatically establishing an ad-hoc network and maintaining the mesh connectivity. The ability
to use multiple-radios and multiple channels can be cashed to increase aggregate throughput of wireless
mesh network. Thus the efficient use of available interfaces and channels without interference becomes
the key factor. In this paper we propose interference aware clustered based channel assignment schemes
which minimizes the interference and increases throughput. In our proposed scheme we have given
priority to minimize interference from nearby mesh nodes in interference range than maximizing channel
diversity. We simulated our proposed work using NS-3 and results show that our scheme improves
network performance than BFSCA and Distributed Greedy CA.
This document provides a literature review of various methods proposed by researchers to improve energy efficiency and security in wireless sensor networks (WSNs). It summarizes several key energy efficient routing protocols like LEACH, PEGASIS and TEEN, as well as security threats like denial of service attacks, wormhole attacks, and Sybil attacks. The document reviews several studies that have developed algorithms and schemes to reduce energy consumption through techniques like dynamic clustering, mobile agent clustering, and randomized routing. It also discusses schemes to prevent security issues like false data injection and improve data authentication. The conclusion states that future work needs to focus on improving battery power and providing better fault tolerance and protection from severe security threats in WSNs.
Energy Proficient and Security Protocol for WSN: A Reviewtheijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
Fast Data Collection with Interference and Life Time in Tree Based Wireless S...IJMER
This document discusses techniques for fast data collection in wireless sensor networks using a tree-based topology. It specifically focuses on minimizing the schedule length for aggregated convergecast (where data is aggregated at each hop) and raw-data convergecast (where packets are individually relayed to the sink).
It first considers time scheduling on a single channel, and then combines scheduling with transmission power control and multiple frequencies to further reduce interference and schedule length. It provides lower bounds on schedule length when interference is eliminated, and proposes algorithms that achieve these bounds.
Evaluation of different channel assignment methods, routing tree topologies, interference models, and their impact on schedule length is also presented. The key findings are that combining scheduling, power control,
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IMPLEMENTING PACKET BROADCASTING ALGORITHM OF MIMO BASED MOBILE AD-HOC NETWOR...IJNSA Journal
With the rapid growth of wireless communication infras,,tructure over the recent few years, new challenges has been posed on the system and analysis on wireless adhoc networking. Implementation of MIMO communication in such type of network is enhancing the packet transmission capabilities. There are different techniques for cooperative transmission and broadcasting packet in MIMO equipped Mobile Adhoc Network. We have employed a model network in the OPNET environment and propose a new scheduling algorithm based on investigating the different broadcasting algorithm. The new broadcasting algorithm improves the packet transmission rate of the network based on energy performance of the network and minimizes the BER for different transmission mode which is illustrated in this paper. The simulations are done in MATLAB and OPNET environment and the simulated result for the packet transmission rate are collected and shown in the tabular form. Also simulate the network for generating a comparative statement for each mobile node. And performance analysis is also done for the model network. The main focus is to minimize BER and improve information efficiency of the network.
Teletraffic Analysis of Overflowed Traffic with Voice only in Multilayer 3G W...IRJET Journal
This document presents a study analyzing the traffic overflow performance of a three-layered wireless mobile network with microcells, macrocells and satellite cells handling voice-only traffic. The three-layered hierarchical network structure is described, with microcells overlaid by macrocells and macrocells overlaid by satellite cells. An existing call admission control scheme is evaluated that prioritizes voice calls, including handling call blocking probabilities, channel utilization, and call dropping probabilities across the different cell layers under varying traffic parameters. Analytical models are developed and numerical calculations are performed to analyze the performance of the call admission control scheme in the three-layered network handling overflowed voice traffic.
Similar to Congestion control, routing, and scheduling 2015 (20)
The American Academy of Neurology now recommends injections of botulinum toxin (Botox) to treat chronic migraines, based on new studies showing a small 15% reduction in migraine frequency. Specifically, the AAN endorses injections of onabotulinumtoxin A. This recommendation comes six years after the FDA approved Botox for migraines, when the AAN previously said evidence was insufficient. Botox is a purified toxin that reduces muscle contractions and pain when used in small amounts.
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This document outlines the hardware and software configuration for a system, including a Pentium processor running at 1.1 GHz with 256 MB RAM and 20 GB hard disk as the hardware configuration, and Windows 95/98/2000/XP as the operating system with vm ware, Hadoop and Mongo DB as the software configuration.
This document discusses the challenges of building a network infrastructure to support big data applications. Large amounts of data are being generated every day from a variety of sources and need to be aggregated and processed in powerful data centers. However, networks must be optimized to efficiently gather data from distributed sources, transport it to data centers over the Internet backbone, and distribute results. The unique demands of big data in terms of volume, variety and velocity are testing whether current networks can keep up. The document examines each segment of the required network from access networks to inter-data center networks and the challenges in supporting big data applications.
The document lists 9 academic papers related to android computing from 2015. The papers cover topics such as android malware detection using decompiled source code, the impact of API changes on user ratings of android apps, analyzing permission leakage between android apps, using smartphones to crowdsource image sensing, secure barcode-based visible light communication for smartphones, recommending friends in social networks semantically, analyzing obfuscated smartphone malware, controlling photo sharing on social networks, and continuous user identity verification for secure internet services.
This document proposes a real-time big data analytical architecture for remote sensing applications to address scalability issues in handling huge amounts of data. The architecture includes a remote sensing data acquisition unit to collect raw data, a data processing unit to filter and load balance the useful data, and a data analytics decision unit to compile results and generate decisions. It also describes algorithms for filtration and load balancing, processing and calculation, aggregation and compilation, and decision making.
k-means clustering aims to partition n observations into k clusters in which each observation belongs to the cluster with the nearest mean, serving as a prototype of the cluster. This results in a partitioning of the data space into Voronoi cells.
Hasbe a hierarchical attribute based solution for flexible and scalable acces...parry prabhu
The document proposes a Hierarchical Attribute-Set-Based Encryption (HASBE) scheme to provide scalable and flexible access control for outsourced data in cloud computing. HASBE extends Ciphertext-Policy Attribute-Set-Based Encryption with a hierarchical user structure for scalability. It also supports compound attributes for flexibility and fine-grained access control. HASBE employs multiple expiration times to more efficiently revoke users compared to existing schemes. The security of HASBE is formally proven based on CP-ABE security. The scheme is implemented and experiments show it efficiently and flexibly handles access control for outsourced cloud data.
The document lists 9 academic papers related to android computing from 2015. The papers cover topics such as android malware detection using decompiled source code, the impact of API changes on user ratings of android apps, analyzing permission leakage between android apps, using smartphones to crowdsource image sensing, secure barcode-based visible light communication for smartphones, recommending friends in social networks semantically, analyzing obfuscated smartphone malware, controlling photo sharing on social networks, and continuous user identity verification for secure internet services.
Privacy preserving public auditing for regenerating-code-based cloud storageparry prabhu
This document proposes a public auditing scheme for cloud storage using regenerating codes to provide fault tolerance. It introduces a proxy that is authorized to regenerate authenticators in the absence of data owners, solving the regeneration problem. The scheme uses a novel public verifiable authenticator generated by keys that allows regeneration using partial keys, removing the need for data owners to stay online. It also randomizes encoding coefficients with a pseudorandom function to preserve data privacy.
The document describes 5 database tables with their field names and data types:
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This project document outlines a student project that was implemented based on a referenced paper. It includes sections on the project objective, abstract, literature survey of several relevant papers, a description of the proposed system, advantages of the proposed system, and references. The student's name, registration number, and guidance are listed at the top.
Java requirements include a Pentium IV 2.4 GHz processor, 40GB hard disk, 15" VGA color monitor, and 256MB RAM for hardware. The software requirements are Windows XP for the operating system, JSP for the front end, and SQL Server for the back end database.
system requirement for network simulator projectsparry prabhu
This document outlines the system requirements for hardware including a processor over 500 MHz, 128MB of RAM, 10GB of hard disk space, and 650MB of compact disk space. It also lists the software requirements including an operating system of Windows 2000/XP or Fedora 8.0, the TCL coding++ programming package, and the VMware Workstation tools.
system requirements for android projectsparry prabhu
The system requirements document outlines the minimum hardware and software specifications. The hardware requires an Intel Pentium 4 CPU clocked at 3.0 GHz or higher, 512 MB of RAM, a 40 GB hard drive, a 15-inch color monitor, and an internet keyboard. The software requires the Android operating system and an Android SDK version 2.3 or higher to develop applications for an Android mobile device.
Sri Guru Hargobind Ji - Bandi Chor Guru.pdfBalvir Singh
Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
afterwards, Guru Arjan was arrested, tortured and killed by order of the Mogul Emperor
Jahangir.
• Guru Hargobind's succession ceremony took place on 24 June 1606. He was barely
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• As ordered by Guru Arjan Dev Ji, he put on two swords, one indicated his spiritual
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• He had a long tenure as Guru, lasting 37 years, 9 months and 3 days
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We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
Online train ticket booking system project.pdfKamal Acharya
Rail transport is one of the important modes of transport in India. Now a days we
see that there are railways that are present for the long as well as short distance
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system. The Online Train Ticket Management System will help in reserving the
tickets of the railways to travel from a particular source to the destination.
2. QU et al.: WIRELESS NETWORKS WITH INTERFERENCE CANCELATION CAPABILITIES 3109
Clearly, efficient link scheduling together with SIC help in
promoting better spatial reuse as well as transmission con-
currence, resulting in increased throughput performance. In
this paper, we consider a wireless network where nodes are
endowed with SIC capabilities, and we study the problem of
link scheduling, under the SINR interference model, in the
context of a cross-layer network design.
We consider a network utility maximization (NUM) problem
(similar to [25] and [26]) in a multihop wireless network and
decouple the cross-layer optimization into congestion control
and routing/scheduling subproblems. The congestion control
subproblem can easily be solved at the source node of each flow
by only using local information, and following a back pressure
framework, the routing/scheduling subproblem is converted
into a weight scheduling problem where the weight information
can be illustrated as some scale of the queue length at each
node. However, as mentioned earlier, previous work has shown
that the link scheduling under a binary interference model is
an NP-hard problem [2] and under the SINR model as NP-
complete [5], both with and without SIC, and polynomial-time
approximation algorithms are presented (e.g., [10] and [24]).
Scheduling methods such as maximum weight scheduling [11]
and greedy maximal scheduling (GMS) [12] have shown to
achieve 100% throughput in most practical wireless networks
with the second method being more amenable to distributed
implementation. In this paper, we will consider the GMS ap-
proach for solving the link scheduling problem under the SIC
constraints and the physical interference model; now, given the
complexity of the scheduling problem in centralized settings,
we develop a decentralized method for solving it. Our main
contributions are as follows. First, we revise the interference
localization method in [19] and show that it can be used to
maintain the interference constraints in a network with SIC
capabilities. Second, we present a search-based method for
determining the minimum interference neighborhood of each
link. Our design reveals that the network throughput perfor-
mance is mainly dependent on how much local information
can be coordinated at each communication link. We show that
our decentralized algorithm yields the same maximal schedule
obtained by the centralized GMS method.
The rest of this paper is organized as follows. In Section II,
we briefly survey the work related to cross-layer optimization
with and without SIC. Our system model, the interference
localization technique, and problem formulation are presented
in Section III. Section IV presents the dual decomposition for
decoupling the cross-layer design problem as well as the design
of our decentralized scheduling method. Finally, numerical
results are presented in Section V, and conclusions are drawn
in Section VI.
II. RELATED WORK
Recently, there have been growing interests to exploit inter-
ference among adjacent concurrent transmissions to increase
the network throughput. Mitran et al. in [13] formulated a
cross-layer design optimization to solve the joint problem of
routing and scheduling in a multihop wireless network with
advanced physical-layer techniques for interference cancela-
tion, such as SIC, superposition coding, and dirty-paper coding.
The authors formulated the problem of routing and scheduling
under the physical interference model as a max–min optimiza-
tion problem and developed a column generation method for
solving it efficiently. The authors have shown that SIC signifi-
cantly improves the network performance and, in particular, the
max–min per node throughput. Jiang et al. in [18] noted that
SIC is a very promising interference exploitation technique for
increasing the network throughput due to its ability in enabling
multiple concurrent transmissions. Upon developing a cross-
layer optimization framework for the routing and scheduling
problem, the authors studied the optimal interaction between
interference exploitation, through SIC, and interference avoid-
ance, through link scheduling. The authors have shown that
substantial performance gains can be achieved when both tech-
niques are combined.
Now, the asymptotic transmission capacity of ad hoc net-
works with SIC is studied in [15] and [16]; the former con-
sidered that all signals within one hop from transmitters can be
successfully decoded, and the latter supposed a more realistic
SIC model in their analysis. Sen et al. in [17] studied the extent
of throughput gains that is possible under SIC from a MAC-
layer perspective. They argued that only little gains could be
achieved in restricted scenarios (mainly for upload traffic in
wireless local area networks). Furthermore, when transmitters
choose their bit rates independently, not much gain can be
achieved. However, the authors showed (in a two-transmitter
scenario) that one way to maximize the gain is through transmit
power level selection such that the feasible bit rate is equal for
both transmissions. Lv et al. in [22] proposed a layered protocol
model and a layered physical model (to model the interference)
and studied the problem of link scheduling to characterize the
advantages of SIC. The authors analyzed the capacity of a net-
work with SIC and demonstrated the importance of designing
SIC-aware scheduling. It was shown that significant through-
put gains (20%–100%) can be obtained in chain/cell network
topologies. The problem of link scheduling with interference
cancelation using the SINR interference model is studied in
[23] where Yuan et al. assumed multiuser decoding receivers.
The authors showed that the optimal scheduling problem with
(successive or parallel) interference cancelation is NP-hard
and developed compact linear programming (LP) methods for
obtaining exact solutions. The authors showed that in the lower
SINR regime, interference cancelation yields significant im-
provements. Similarly, in [24], Goussevskaia and Wattenhofer
studied the same problem but developed approximation algo-
rithms for solving the scheduling problem in polynomial time.
SIC has shown to achieve up to 20% performance gains over
networks that do not have interference cancelation capabilities.
It should be noted that all of the aforementioned methods
solve the link scheduling problem in a centralized manner;
given the complexity of the problem, decentralized methods are
more practical. In [25], a distributed method that jointly adapts
decisions made by different layers is proposed. Chen et al.
presented then a dual driven decomposition approach for the
original problem, which is further decomposed into two sub-
problems (one for congestion control and another for routing/
scheduling), and the three are correlated through Lagrangian
3. 3110 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 64, NO. 7, JULY 2015
multipliers. A fully distributed algorithm following the
decomposition is then presented. In [31] and [32], Joo and
Shroff and Joo et al., respectively, revised the distributed
scheduling methods in wireless networks and classified them
into different categories. For the graph-based interference
model, the authors mainly focused on the problem of schedul-
ing and proposed a revision of the GMS algorithm to satisfy the
distributed design. For the more practical interference model,
Le et al., in [19], investigated the link scheduling problem by
considering GMS; to simplify the complex relationship govern-
ing the interference, the authors presented a method to localize
the interference around each link, thereby each link coordinates
its scheduling within a local neighborhood while maintain-
ing scheduling feasibility. The authors subsequently devel-
oped a decentralized scheduling method, which was shown to
yield maximal link scheduling similar to the centralized GMS
method. These decentralized methods did not however consider
network with interference cancelation capabilities.
Note that our work is similar to [25] and [26] in that we
try to design an efficient distributed cross-layer method to
improve the performance of wireless multihop networks. Our
work, however, differs from previous work in that we consider
networks with SIC capabilities in our distributed cross-layer
design with the SINR interference model. This makes the
design of a decentralized method more complicated because of
the particularity of the SIC constraints.
III. SYSTEM MODEL
A. Network Model
We consider a network of N nodes and L links; we assume
stationary nodes, each equipped with SIC capability. Let dn,n
be the Euclidean distance between two nodes n and n , and let
Gnn be the channel gain from n to n such that Gnn = d−pl
n,n ,
where pl is the path-loss index. The transmission power at each
node is assumed to be fixed and equal to Pw. Let F be the set of
flows in the network, where each flow f (f ∈ F) is identified by
a source s(f) and a destination d(f) and a transmission rate yf .
B. Interference Model With SIC
In the physical interference model (also known as the ad-
ditive interference model), in the presence of concurrent trans-
missions on neighboring links, one transmission (e.g., on link i)
is successful if the SINR at the intended receiver is above a
certain threshold β. Then, the physical interference model can
be formulated as
SINRt(i),r(i) =
PwGt(i),r(i)
η + ∀ n∈NA−t(i) PwGn,r(i)
≥ β (1)
where η is the background noise power. NA is the set of all
active nodes in the network, and t(i) and r(i) are the transmitter
and the receiver of link i. β is the minimum SINR threshold
that must be maintained to support a successful transmission
on link i while guaranteeing a tolerable bit error rate. If the
SINR requirement is not met, then the received packet cannot
be correctly extracted from the received signal. In this paper,
we assume β ≥ 1.
Now, SIC allows a signal to be correctly decoded in the
presence of other concurrent transmissions. Here, the receiver
starts decoding the strongest signal from the combined received
signal; then, the decoded signal is subtracted, and the process
is repeated on the residual signal until the signal of interest is
either decoded or no more decoding is possible. This technique
therefore allows a signal to be correctly received given that
other stronger signals are decoded first. Next, we illustrate the
SINR constraints in the presence of SIC. Consider two links
i and i adjacent to each other. Denote by P1
r(i)(P2
r(i)) the
strength of the signal received at destination r(i) from t(i)
(respectively, from t(i )) and suppose P2
r(i) > P1
r(i). Here, r(i)
will attempt to decode the signal received from t(i ) first; this
signal can be decoded if
SINR2
r(i) =
P2
r(i)
η + P1
r(i)
≥ β. (2)
If the signal of t(i ) is successfully decoded at r(i), then r(i)
will subtract it from the combined signal and will attempt to
decode the signal arriving from t(i), i.e.,
SINR1
r(i) =
P1
r(i)
η
≥ β. (3)
The given procedure can be generalized in a straightforward
manner to any number of transmissions.
C. Link Scheduling With Interference Localization
We consider a time-division-multiple-access-based MAC
layer where time is divided into slots of equal length, and each
time slot has two parts: a schedule and a transmission. The
schedule part has several intervals, and each interval is further
divided into minislots. We define the set of links that can be
concurrently active in the same time slot (without violating the
SINR requirements) as a (feasible) configuration (or conf for
short). Then, our objective is to generate a new configuration
during the “schedule” period under SIC constraints and trans-
mits data during the “transmission” period (each active link will
transmit one packet during the “transmission” period). Note
that, in a wireless network without SIC capabilities, in [19],
Le et al. noted that only those concurrent transmissions within
a neighborhood of a particular link may create significant
cumulative interference at the receiver of this link. Accordingly,
they presented an “interference localization” technique that
allowed them to decentralize the link scheduling problem. The
authors presented a method to determine for each link a neigh-
borhood such that interference from active links outside this
neighborhood will have negligible impact on received signal
at the receiver of this link. Namely, for link l, the maximum
interference that can be tolerated is
Imax
l =
PwGt(l),r(l)
β
− η. (4)
Let INl and nINl denote the interference neighborhood
and noninterference neighborhood of link l. INl is a circle
4. QU et al.: WIRELESS NETWORKS WITH INTERFERENCE CANCELATION CAPABILITIES 3111
centered around the receiver of l and whose radius will be
determined later. All links whose transmitters are inside INl
will be able to exchange information (therefore coordinate)
with the transmitter of link l for scheduling purposes. nINl
(complement of INl) contains the set of links whose cumula-
tive interference is assumed to be negligible at rl. Le et al. in
[19] have shown that given a constant (0 < < 1), for link l
to be feasible, the upper bound on the interference coming from
active links located in INl should not exceed (1 − )Imax
l , and
the total interference coming from links located in nINl cannot
exceed Imax
l . Therefore, when all active links in some set are
feasible, we obtain a feasible configuration.
Now, to account for the SIC property of the nodes in the
network, we first revise the interference localization technique
presented earlier as follows. For a particular link l, we divide the
network into three regions: the strongest signal area, the inter-
ference area, and the noninterference area. The strongest signal
area (Al) refers to a circular area with radius dt(l),r(l) centered
around the receiver of link l. The interference area refers to the
ring-like area (INl − Al) with radius from dt(l),r(l) to a certain
length λ(l) (λ(l) ≥ dt(l),r(l)) centered around the receiver of
link l. The noninterference area denotes the region outside the
interference area (nINl). Next, we introduce the definition of
vector
−→
λ .
Definition 1: For any feasible link l, λ(l) denotes the lower
bound of the radius of the interference neighborhood (INl)
such that the total interference coming from links located in
the noninterference area does not exceed Imax
under SIC
constraints.
We assume that each link l (l ∈ L) is able to communicate
with any link whose transmitter is located in INl, or any link l
such that t(l) ∈ INl , to exchange link weight information and
coordinate the link scheduling. Definition 1 implies that there is
a relationship between and
−→
λ (we will present a procedure to
compute
−→
λ based on in the following section). Furthermore,
can be used to control the potential scheduling overload, and
we will verify in Section V that will have a significant effect
on the achievable network performance.
Note that, in any feasible configuration, we assume that all
“active” links l (such that t(l ) ∈ Al) have stronger received
signals at r(l) than the signal arriving from t(l), and therefore,
using SIC, r(l) is capable of successively decoding those
signals prior to decoding the signal arriving from t(l).
Definition 2: Given a certain
−→
λ , Θ(
−→
λ ) is a class of schedul-
ing algorithms such that a particular scheduling method will
belong to Θ(
−→
λ ) if it yields an active schedule satisfying
the following constraints: 1) For any active link l ∈ L, the
total interference coming from active transmitters located in
INl − Al does not exceed (1 − )Imax
(l); and 2) let k de-
note the link from any active transmitter located in Al to
r(l); then, the cumulative interference at r(k) = r(l) coming
from active transmitters located in INk − Ak does not exceed
(1 − )Imax
(k).
The second constraint in the given definition implies that all
active transmitters within the neighborhood of r(l) (i.e., in Al)
should have their signals decoded at r(l) prior to decoding the
signal arriving from t(l). Here, r(l) will attempt to success-
fully decode each of these arriving signals (using SIC); this is
possible because for each signal, we assume that the cumulative
interference from active transmitters located in INk − Ak does
not exceed (1 − )Imax
(k), which is required for successful
decoding of the signal of t(k) at r(l).
Combining Definitions 1 and 2, it can be shown that for any
(0 < < 1), there exists a vector
−→
λ and a class of scheduling
methods Θ(
−→
λ ) such that any scheduling algorithm belonging
to Θ(
−→
λ ) will result in a feasible schedule satisfying the SIC
constraints. This is summarized in the following theorem.
Theorem 1: Given any 0 < < 1, there exists a vector λ
that satisfies Definition 1, and the result of schedule Θ(λ) that
satisfies Definition 2 is feasible under SIC constraints.
D. Problem Formulation
Following the given discussion, we assume that all active
links in one conf can simultaneously transmit. Denote by E
the set of all possible configurations/schedules, where each
conf is indexed by e. Each conf (e) is represented by a
|L|-dimensional rate vector −→r e
, where for each link l, re
l can
be defined as
re
l =
c, if l ∈ e
0, otherwise
(5)
where c is a constant link transmission rate. We define the
feasible rate region Γ as the convex hull of these rate vectors.
We assume through time sharing that all interior points of Γ
are attainable. We define a link-flow matrix v to describe the
routing of flows in the network, where each element vlf ∈
v(∀ l ∈ L, f ∈ F) corresponds to the fraction of flow f deliv-
ered over link l. We assume a utility function U(yf ) to be twice
differentiable, increasing, and strictly concave [25]. Our design
target can be summarized in the following utility maximization
problem:
[OBJECTIVE]
max
yf ≥0,∀ f∈F
f∈F
U(yf ). (6)
Similar to [26], a feasible routing must satisfy two constraints:
the interference and link capacity constraints (7) and the flow
balance constraints (8).
[CONSTRAINTS]
f∈F
vlf ∈ Γ ∀ l ∈ L (7)
yif + Υ−
if ≤ Υ+
if ∀ i ∈ N, f ∈ F (8)
where yif (i ∈ N, f ∈ F) denotes the node-flow variable such
that yif = yf when i = s(f), and otherwise yif = 0. Υ−
if =
l∈L:r(l)=i vlf and denotes the fraction of flow f incoming
into node i, and Υ+
if = l ∈L:t(l )=i vl f denotes the fraction
of flow f outgoing of node i.
5. 3112 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 64, NO. 7, JULY 2015
IV. DISTRIBUTED CROSS-LAYER DESIGN WITH
SUCESSIVE INTERFERENCE CANCELLATION
A. Dual Decomposition
Similar to [25] and [26], we resort to the dual driven
Lagrangian decomposition approach to get a distributed so-
lution. For completeness, we briefly describe the process of
decomposition, and the detailed demonstration can be found in
[25]. Consider the dual problem of primal problem (6), i.e.,
min
uif ≥0,∀ i∈N,f∈F
D(u) (9)
with partial dual function
D(u) = max
yf ≥0,v∈Γ
×
⎧
⎨
⎩
f∈F
U(yf ) −
f∈F i∈N
uif yif + Υ−
if − Υ+
if
⎫
⎬
⎭
(10)
where uif is a Lagrangian multiplier, and u = [uif ]i∈N,f∈F .
Then, (10) can be further decomposed into the following two
subproblems:
D1(u) = max
yif ≥0
f∈F i∈N
(U(yif ) − yif uif ) (11)
D2(u) = max
v∈Γ
f∈F i∈N
uif Υ−
if − Υ+
if . (12)
Here, D1(u) can be solved by (13), which is the standard rate
control problem at the source node of each flow, i.e.,
yf = U −1
(uf ) (13)
where uf = uif if node i = s(f). For the routing/scheduling
problem D2(u), we have the following identity:
D2(u) = max
v∈Γ
l∈L
vlf∗ max
f∈F
ut(l)f − ur(l)f (14)
where f∗
= arg maxf∈F {ut(l)f − ur(l)f }, l ∈ L.
Based on (14), the routing/scheduling problem can be solved
by the following two-step process.
Step 1) For each link l, we can use local informa-
tion u to find a flow f∗
that satisfies f∗
=
arg maxf∈F {ut(l)f − ur(l)f }. Let wl = ut(l)f∗ −
ur(l)f∗ be the weight of link l. Here, wl can also
be interpreted as the scaled queue length at link l
with flow f∗
. In each time slot, the links in one
conf can be active to send data to the receivers (we
assume one packet transmission per active link per
time slot). The given algorithm can be interpreted as
a back pressure process to solve the routing problem.
Step 2) We convert (14) into its reduced form as follows:
D2(u) = max
v∈Γ
l∈L
vlf∗ wl. (15)
The formulation of (15) can be seen as an ordinary link
scheduling problem where each link is associated with its
weight wl. However, it is difficult to solve the scheduling prob-
lem because the interference relationship under the physical
interference model (SINR) is nonconvex and combinatorial. In
the sequel, we present a simplified distributed link scheduling
method taking into account the SIC constraints and using the
interference localization technique presented earlier. We first
propose a method to calculate the vector
−→
λ under a certain ,
and then, a distributed scheduling method is proposed under
SIC constraints.
B. Identifying the Interference Neighborhood
Here, we present a binary-search-based method to determine
vector
−→
λ under a certain value of . Recall that, according
to Definition 1, λ(l) is the lower bound of the radius of the
interference neighborhood INl, which guarantees that, under a
feasible scheduling method (see Definition 2), the total interfer-
ence coming from links in the noninterference region (nINl)
does not exceed Imax
. For a link l, denote dmax
(l) as the
distance from the farthest node in the network to the receiver of
link l. The search procedure for link l starts from dmax
(l), and
we use a bisection search method to reduce the gap between
the current search radius and the optimal λ(l). At every level
of current radius, we have to determine the maximum inter-
ference coming from the active links whose transmitters are
located outside the current radius. One simple way to decide the
maximum interference is to sum up the received signals from
all transmitters outside the current radius; it should be noted
that since some of these transmitters may not be active in our
configuration, this calculated maximum interference represents
an upper bound. An alternative approach is to solve a simple
SIC-based scheduling problem on the links whose transmitters
are located outside the current radius. We repeat this procedure
(of updating the radius of interference neighborhood) for link
l until a tolerable performance is attained. This procedure is
illustrated in Algorithm 1. Note that Algorithm 1 is a central-
ized procedure that needs to be performed only once for a static
wireless network.
All links in the area outside the current radius are initially
stored in a link set Ψ. For current link l, we associate weight
attribute wal(l ) = PwGt(l ),r(l), ∀ l ∈ Ψ and 0 otherwise. We
also define a binary variable pi(i ∈ L), which is equal to 1 when
link i is active, and otherwise, it is zero. Then, we define our
optimization objective as
Maximize :
i∈L
wal(i)pi. (16)
Similarly, we define another binary variable qt(j)(j ∈ L),
which is equal to 1 when node t(j) is an active transmitter,
and otherwise, it is zero. Let L+
n be the set of links whose
transmitter is node n and L−
n be the set of links whose receiver
is node n. Therefore, we have
qt(j) =
i∈L+
t(j)
pi (17)
i∈L+
n
pi ≤ 1. (18)
6. QU et al.: WIRELESS NETWORKS WITH INTERFERENCE CANCELATION CAPABILITIES 3113
In this paper, we only consider the half-duplex mode at each
node. Then, our half-duplex constraints can be written as
pi + pj ≤ 1 ∀ n ∈ N : i ∈ L−
n, j ∈ L+
n . (19)
Similar to [18], we use the concept of residual-SINR or r-SINR
for short. Due to its interference cancelation capability, a
receiver node can sequentially cancel all interfering signals,
which are stronger than the one of interest; therefore, one only
needs to consider the interference from senders whose signals
are weaker than that of the intended one. The r-SINR can be
defined as
r_SINRt(i),t(i) =
PwGt(i),r(i)
Gt(k),r(i)≤Gt(i),r(i)
k=i,t(i)=t(k) PwGt(k),r(i)qk + η
.
(20)
Indeed, when scheduling variable vp
i = 1 (link i is active), this
implies that all other stronger received signals from adjacent
senders at r(i) have been correctly decoded, and the decoding
of the signal of interest at link i is also successful. Namely, if
vp
i = 1, then the following two constraints should be satisfied:
r_SINRt(i),r(i) ≥ β, (pi = 1, i ∈ L) (21)
r_SINRt(j),r(i) ≥ β, j =i, t(j)=t(i), Gt(j),t(i) ≥Gt(i),r(i),
pj = 1, j, i ∈ L) . (22)
To convert the SIC constraints into an LP format, we define a bi-
nary variable ρi,t(j) to describe the relationship of pi and qt(j).
Let ρi,t(j) = 1 if and only if pi = 1 and qt(j) = 1; otherwise, it
is zero. Then, the relationship can be written as follows:
pi ≥ ρi,t(j) (23)
qt(j) ≥ ρi,t(j) (24)
ρi,t(j) ≥ pi + qt(j) − 1. (25)
Now, we can use mathematical programming to describe
constraints (21) and (22) as
PwGt(j),r(i) −
Gt(j),r(i)≥Gt(k),r(i)
t(k)=t(j)
βPwGt(k),r(i)qt(k) − βη
≥ 1 − ρi,t(j) Mi,t(j)
Mi,t(j) = PwGt(j),r(i)
−
Gt(j),r(i)≥Gt(k),r(i)
t(k)=t(j)
βPwGt(k),r(i) − βη (26)
PwGt(i),r(i) −
Gt(i),r(i)≥Gt(k),r(i)
t(k)=t(i)
βPwGt(k),r(i)qk − βη
≥ (1 − pi)Hi
Hi =PwGt(i),r(i) −
Gt(i),r(i)≥Gt(k),r(i)
t(k)=t(i)
βPwGt(k),r(i)−βη. (27)
Algorithm 1: Determination of Interference Neighbourhood
1 Initialize (0 < < 1);
2 Initialize itrCut;
3 for l : l ∈ L do
4 Initialize curr.decision = 1;
5 Initialize curr.radius = dmax
(l);
6 Initialize success.radius = dmax
(l);
7 Initialize curr.decision = 1;
8 for i = 1 to itrCut do
9 curr.interval = (dmax
(l) − dt(l),r(l))/2i
;
10 curr.radius = curr.radius + (1 − curr.
decision) ∗ curr.interval − curr.decision ∗
curr.radius;
11 Generate wal based on curr.radius;
12 Solve optimal objective (16) under constraints
(17)–(19), (23)–(27);
13 if (16) > Imax
then
14 curr.decision = 0;
15 else
16 success.radius = curr.radius;
17 curr.decision = 1;
18 end
19 λ(l) = success.radius;
20 end
21 end
C. Distributed Scheduling Algorithm With SIC
Based on Algorithm 1, we can calculate
−→
λ under a certain
value of . Let Δ1
l be the set of all links k such that t(l) is
located in Ak, Δ2
l be the set of all links k such that t(l) is
located in INk − Ak, and Δl = Δ1
l Δ2
l . At the beginning
of each scheduling period, each link l broadcasts its weight
information (wl) to links in Δl and ΔIN
l [the set of links whose
transmitters are located in the interference neighborhood of link
l (i.e., in INl)]. We further divide ΔIN
l into two link sets:
ΔIN1
l and ΔIN2
l . The former denotes the set of links k such
that t(k) is located in Al, and the latter denotes the set of links
k such that t(k ) is located in INl − Al. The weight of link
l is computed as illustrated in Section IV-A. We assume that
each link l(l ∈ L) maintains two local link sets, i.e., the current
active link set (currsl for short) and a candidate link set (cansl
for short). The former contains links that have been added
into a feasible configuration conf in a particular scheduling
period, and the latter contains links that are candidate links
to be added into conf. At the beginning of each scheduling
period, we initialize currsl = ∅ and cansl = {l, Δl ΔIN
l }.
Each scheduling period consists of several intervals, and in each
interval, each link l makes a decision as to whether it should
be added into currsl or removed from cansl. Therefore, the
purpose of our scheduling method is to generate a new con-
figuration that satisfies the SIC constraints under the physical
interference model such that the sum of the weights of the
links in this configuration is the largest possible. Our scheduling
method follows the classical GMS method but is implemented
in a distributed manner.
7. 3114 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 64, NO. 7, JULY 2015
To make sure that the new configuration, which has been
generated, satisfies the SIC constraints under the physical in-
terference model, each link will execute two main procedures
as follows. At the beginning of each scheduling interval, each
link l (l ∈ cansl) compares its weight to the weights of links
in cansl. If link l has the largest weight among all links in
cansl, it will run Algorithm 2 to try to add itself into currsl.
The detailed process is illustrated next. Link l first broadcasts a
REQ message to links in Δl. Any link in Δl will add link l into
a local auxiliary link set (auxs for short); now, any link l ∈
{currsl auxsl} will determine whether it remains feasible
under SIC constraints upon adding link l to the current schedule
as follows. For each link l ∈ {currsl auxsl}, we define the
SIC link set (sicsl for short) as the set of links whose trans-
mitters are in ΔIN1
l {currsl auxsl } and receivers are
r(l ). According to Theorem 1, any link l ∈ {currsl auxsl}
satisfies SIC constraints if 1) the total interference (I1) coming
from ΔIN2
l is ≤ (1 − )Imax
(l ) and 2) all links k ∈ sicsl
are feasible (i.e., total interference (I2) coming from ΔIN2
k is
≤ (1 − )Imax
(k)).
According to the given procedure, if any link l ∈
{currsl auxsl} does not satisfy the SIC constraints, then
link l will send an ERROR message to link l indicating that link
l cannot be added to the configuration (that is, link l is causing
strong interference making the current schedule not feasible).
If link l ∈ auxsl does not receive any ERROR message from
its neighbors, it adds itself into currsl, removes itself from
cansl, auxsl, and broadcasts a SUCCESS message to all its
neighbors to update their local link sets (cans, currs, and
auxs). Otherwise, it removes itself from cansl, auxsl and
broadcasts a REMOVE message to all its neighbors to update
their local link sets (cans, auxs). The given process enforces
that when adding a new link to a feasible configuration, the
current schedule remains feasible under SIC constraints.
The main purpose of our second procedure is to remove links
in cans (e.g., link l ∈ cansl), which have no chance of being
added into currs. After the new conf is generated at each
interval, all links l (l ∈ cansl) need to make a decision as to
whether they satisfy SIC constraints as follows. For each link
l ∈ cansl, we define another SIC link set (sicsl for short) as
the set of links whose transmitters are in ΔIN1
l currsl and
receiver is r(l). Similar to the process in the first procedure,
any link l ∈ cansl does not satisfy SIC constraints if 1) the
total interference (I1) coming from ΔIN2
l is > (1 − )Imax
(l)
or 2) for any link k ∈ sicsl is infeasible (i.e., total interference
(I2) coming from ΔIN2
k is > (1 − )Imax
(k )). After the given
process, if there is a link l in cansl that does not satisfy
SIC constraints, then link l will remove itself from cansl and
broadcast a REMOVE message to all its neighbors to update
their local link sets (cans, currs). The given process makes
sure that each link in cans satisfies SIC constraints with the
current schedule.
In our distributed implementation, we set the number of inter-
vals per scheduling period to a fixed value. In each scheduling
interval, each link will run Algorithms 2 and 3 to generate new
feasible schedule/configuration during the scheduling period.
Once a schedule is obtained, links that have been selected will
transmit in the transmission period one packet each.
Algorithm 2: Distributed Scheduling Method With SIC
(Link l)
1 Link l broadcast REQ message to all links in Δl;
2 for link l in Δl {currsl auxsl} do
3 if link l received REQ message from link l then
4 Link l adds link l into auxsk;
5 Link l calculates cumulative interference I1;
6 if I1 > (1 − )Imax
(l )) then
7 Link l broadcasts ERROR message to link l;
8 else
9 Generate sicsl ;
10 for k : k ∈ sicsl do
11 Link k temporarily calculates cumulative
interference I2;
12 if I2 > (1 − )Imax
(k) then
13 Link l broadcasts ERROR message to link l;
14 end
15 end
16 end
17 end
18 end
19 if Link l receives no ERROR messages then
20 currsl = currsl l;
21 cansl = cansl − l;
22 auxsl = auxsl − l;
23 link l broadcasts a SUCCESS message to all its neigh-
bors to update their local link sets(cans, currs, auxs);
24 Goto Algorithm 3;
25 else
26 cansl = cansl − l;
27 link l broadcasts a REMOVE message to all its neigh-
bors to update their local link sets(cans, auxs);
28 end
Algorithm 3: Distributed Scheduling Method With SIC
(Part II)
1 for link k in Δl cansl do
2 if link k received a SUCCESS message from link l then
3 Link k calculates cumulative interference I1;
4 if I1 > (1 − )Imax
(k)) then
5 Link k broadcasts a REMOVE message to its neigh-
bors to update their local link sets(cans);
6 else
7 Generate sicsk;
8 for i : i ∈ sicsk do
9 Link i calculates cumulative interference I2;
10 if I2 > (1 − )Imax
(i) then
11 Link k broadcasts a REMOVE message to its
neighbors to update their local link sets(cans);
12 end
13 end
14 end
15 end
16 end
8. QU et al.: WIRELESS NETWORKS WITH INTERFERENCE CANCELATION CAPABILITIES 3115
D. Joint Transport, Routing, and Scheduling With SIC
Consider the dual problem (9) and suppose that the function
D(u) is not necessarily differentiable. Therefore, (9) can be
solved using the subgradient method. Now, it is easy to verify
that
v+
if (u) − yif (u) + v−
if (u) (28)
is a subgradient of D(u) at point u. Thus, based on the subgradi-
ent method, the update algorithm can be formulated as follows:
uif (t+1)= uif (t)+α v+
if (u(t))− yif (u(t))+v−
if (u(t))
+
(29)
where α is a positive step size. Equation (29) achieves optimal-
ity when α is set to a sufficiently small value [25]. The given
dual algorithm (presented in Section IV-A) solves the cross-
layer problem through a distributed manner where at the trans-
port layer, nodes in the network individually update their prices
according to (29) and the source of each flow f individually
adjusts its rate (y) according to the local congestion price (u);
for solving the routing/scheduling subproblem, we generate a
new conf at each time slot by using Algorithms 2 and 3, which
work in a distributed manner. We summarize our joint conges-
tion control, routing, and scheduling with SIC in Algorithm 4.
Algorithm 4: Distributed Cross-Layer Design With SIC
1 Initialize max iteration count as itrmax;
2 Initialize y, v, u;
3 for i = 1 to itrmax do
4 for n ∈ N do
5 node n updates u by calculating (29);
6 end
7 for f ∈ F do
8 Source node of flow f updates y by calculating (13);
9 end
10 for l ∈ L do
11 link l updates wl;
12 end
13 Generate a feasible conf by Algorithms 2 and 3;
14 Data Transmission based on currently obtained
schedule;
15 end
E. Complexity Analysis
The whole procedure includes a centralized process for
identifying the interference neighborhood (see Algorithm 1)
and a link scheduling process under SIC, which is done in
a distributed manner at each iteration (see Algorithms 2 and
3). To analyze the complexity of the first part, we convert the
inverse LP (ILP) problem into a complete binary tree for the
worst case of solving the optimal objective (16). A route that
starts from the root of the tree to the leaf is a feasible solution
(or schedule). Based on backtracking, it is clear that the time
Fig. 1. Eight-node network topology.
complexity of a tree traversal search is O(2n
), where n is the
number of links in wal. However, in most cases, there is no need
for a complete traversal search, owing to the SINR constraints
between links. In practice, we can prune some invalid branches
(i.e., the branch-and-cut method [34]) to improve the efficiency
of the search.
For the run time complexity of the distributed scheduling
with SIC, we omit the communication overload during the
scheduling interval and only focus on the worst case compu-
tation analysis. As shown in Algorithms 2 and 3, it is easy to
verify that the time complexity of links in cansl is O(n) +
O(n2
) = O(n2
) (i.e., the weight comparison and the order of
SIC decoding), where n is the number of feasible neighbors
(i.e., active links) for link l. Given that there is no need to com-
pare the weight information in links in currsl auxsl sicsl,
their run time complexity is O(n2
). For each link that is not in
cansl currsl auxsl sicsl, it keeps silent and therefore
no calculation. Hence, the worst-case run time at each link is
O(n2
), which is polynomial.
V. NUMERICAL RESULTS
Here, we present numerical results to study the performance
of the cross-layer design method for solving the problem of
joint transport, routing, and scheduling (JTRS) in wireless
networks with interference cancelation. We are particularly in-
terested in studying the efficiency of the distributed scheduling
(JTRDS) method with SIC, and we present comparisons with
centralized scheduling methods [JTRCS; both Pick & Com-
pare (P&C) and GMS]. We also present comparisons of our
cross-layer design method with and without SIC to assess the
benefits of interference cancelation (JTRDS-SIC and JTRDS,
respectively). We use a CPLEX solver to solve the ILP problem
in Algorithm 1 to determine the radius of the interference
neighborhood for each link. For our evaluation, we consider two
random networks (Network 1 and Network 2), with eight nodes
(48 links) and 15 nodes (124 links), each randomly distributed
in a square region of 100 m × 100 m. The topologies of
the networks are shown in Figs. 1 and 2. Under the physical
interference model, the transmission power of each node is set
to Pw = 0.001 W. We assume the path-loss index pl = 4; the
background noise η is set to 10−10
W; the SINR threshold for
a successful transmission is β = 1, = 0.05 (unless otherwise
specified); and the transmission capacity of each link is c = 1
(packet/time slot). We assume that there are two flows and four
flows in Network 1 and Network 2, respectively.
9. 3116 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 64, NO. 7, JULY 2015
Fig. 2. Fifteen-node network topology.
Fig. 3. Utility achieved by JTRDS-SIC ( = 0.05) and JTRCS-SIC (P&C).
We start by evaluating the performance benefits of JTRDS-
SIC in Network 1. There are two flows in the network (Flow 1:
node 1 → node 8; Flow 2: node 3 → node 7). We compare our
distributed method with P&C, which is a centralized scheduling
method and is shown to achieve 100% throughput [19], [20]. In
the P&C scheduling method, we randomly generate a maximal
schedule under SIC constraints at each time slot (by randomly
selecting links to be included in the schedule as long as they
satisfy the interference constraints) and compare the current
schedule with the schedule generated in the previous time slot;
the schedule with larger weight (sum of the link weights) is
always selected for data transmission at each time slot. In our
distributed method, we set = 0.05. Figs. 3 and 4 show the
utility and the congestion price of both methods. Clearly, the
figures show that our distributed method quickly converges
to the optimal solution and oscillates around it; however, the
centralized P&C has slower convergence time, which is due to
the random selection of transmission links to be included in the
schedule. To better understand the obtained results, we look at
how these two methods route the two flows and the achievable
individual flow rate; the results are shown in Tables I and II. We
observe that both methods select different routes for the flows
and that flow 1 achieves an optimal rate of 0.8519 (using the
centralized P&C scheduling method), whereas flow 1 achieves
Fig. 4. Congestion prices of JTRDS-SIC ( = 0.05) and JTRCS-SIC (P&C).
TABLE I
AVERAGE RATES OF FLOWS THROUGH DIFFERENT
LINKS WITH JTRCS-SIC (P&C)
TABLE II
AVERAGE RATES OF FLOWS THROUGH DIFFERENT
LINKS WITH JTRDS-SIC
TABLE III
SOURCE NODE, DESTINATION NODE OF EACH FLOW IN THE NETWORK
a flow rate of 0.8332 using the proposed distributed scheduling
method and a gap of 2% between the two methods. Flow 2,
however, achieves the same flow rate of 1 in both methods. It
is to be noted that GMS achieves exactly similar results to our
method (results are omitted in the figures).
Next, we consider the larger network (Network 2) with four
flows (Flow1–Flow4: Table III). We start by studying the effect
of the parameter on the achievable flow rate. We numerically
solve our JTRDS-SIC in this 15-node network, and the obtained
results are shown in Fig. 5. We observe that when is smaller,
10. QU et al.: WIRELESS NETWORKS WITH INTERFERENCE CANCELATION CAPABILITIES 3117
Fig. 5. Flow rates (under JTRDS-SIC) versus .
Fig. 6. Average number of active links per schedule versus .
the achievable flow rates are higher, and as increases, the rate
decreases. Clearly, when is small, the interference neighbor-
hood of a link gets larger (see Fig. 7); therefore, a link l will be
able to coordinate its scheduling/transmission with more links
in its interference neighborhood, i.e., INl. This implies that,
ultimately, each selected schedule may contain, on average,
more active links (see Fig. 6), which, in turn, implies better
spectrum spatial reuse in the network. However, it should be
noted that a larger interference neighborhood may result in
higher scheduling overhead to coordinate the selection of the
schedule. Now, conversely, a larger implies a smaller inter-
ference neighborhood, and as a result, most of the links in the
network will be located outside the neighborhood of a particular
link, preventing any effective coordination in the selection of
the schedule and resulting in lower attainable flow rates.
The flow rate continues to decrease until it reaches a mini-
mum value (at = 0.7) beyond which it starts to increase. This
can be explained as follows. When = 0.7, as we mentioned
earlier, the radius of the interference neighborhood is small (see
Fig. 7), and thus, fewer links may exist within the (INl − Al)
area. Fig. 8 indicates that almost 0 links within that area may
be active. However, according to the protocol, the value of
the tolerable interference assigned to links within that area
Fig. 7. Average radius of neighborhood versus .
Fig. 8. Average number of active links in different areas versus .
is set to (1 − )Imax
; given that almost no links are active
within that area (see Fig. 8), this tolerable interference value
is wasted and would have been better off allocated to links
outside this interference neighborhood (i.e., nINl), where
the other transmission links are located. As increases, the
value of (1 − )Imax
decreases, and more tolerable interference
(i.e., Imax
) is allocated to those links outside the interference
neighborhood of link l, and such links will attempt to schedule
their transmissions concurrently with link l. Fig. 8 shows that
as increases, more links outside the neighborhood are active
in the schedule and none of the links within the interference
neighborhood are. This explains the behavior of the traffic flow
rates shown in Fig. 5 where beyond = 0.7, the rates start
to increase. Fig. 6 shows the average number of active links
per schedule, and as previously explained, smaller indicates
better coordination to construct the schedule and, therefore,
more active links per schedule, hence better spatial reuse, and
larger yields lower spatial reuse.
Finally, we study the benefits of SIC by comparing the
performance of JTRDS-SIC with JTRDS, where in the latter,
nodes do not have any SIC capabilities. The results (individual
flow rates) are shown in Fig. 9, and we use a value of = 0.3.
The selection of = 0.3 is motivated by Fig. 7 where we show
11. 3118 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 64, NO. 7, JULY 2015
Fig. 9. Achievable flow rates (JTRDS-SIC versus JTRS ( = 0.3)).
that both methods have close average radius for the interference
neighborhood. Fig. 9 shows that flows achieve much higher
rates in a network with SIC capabilities (almost twice the rate
is achieved by most of the flows). To better understand, we
observe from Fig. 6 that the JTRDS-SIC method (when =
0.3) has a much better schedule length than that of the JTRDS
method; indeed, the schedule length (i.e., number of active
links per selected schedule) of JTRDS-SIC is almost twice that
of JTRDS. This shows that SIC is effectively managing the
interference in the network and promoting transmission con-
currence, leading to better achievable flow rates in the network.
VI. CONCLUSION
In this paper, we have studied the benefits of SIC in improv-
ing the performance of wireless networks. We considered solv-
ing an NUM problem in the context of cross-layer optimization
of the joint congestion control, routing, and scheduling problem
under the SINR interference model. Through dual decompo-
sition, we divided our design problem into a congestion con-
trol subproblem and a routing/scheduling subproblem. Given
the complexity of the scheduling subproblem, we presented
a decentralized method for solving the link scheduling prob-
lem. Our decentralized method benefits from the interference
localization concept to help neighboring links coordinate their
transmissions, taking into account SIC constraints, and without
causing sufficient interference that may corrupt ongoing sched-
uled transmissions. Our approach to solving the joint design
problem is completely decentralized. We have numerically
solved the cross-layer optimization, and we have shown that
our distributed resource allocation method achieves very close
results to centralized methods (e.g., our achieved results are
below 2% from the centralized P&C scheduling method, which
achieves 100% throughput performance, and we obtain similar
results to the centralized GMS). We also studied the benefits
of SIC, and we have shown that the flows in the network may
achieve up to twice the achievable rates in a network with-
out SIC. We have shown that networks with SIC capabilities
promote better transmission concurrence and, therefore, better
spectrum reuse.
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Long Qu received the B.S. degree in communica-
tion engineering from Zhengzhou University, Henan,
China, in 2010. He is currently working toward
the Ph.D. degree in communication and information
systems with Ningbo University, Zhejiang, China.
From December 2012 to December 2013, he was
a visiting Ph.D. student with Concordia University,
Montreal, QC, Canada. His current research interests
include cross-layer design in wireless communica-
tion systems and wireless network optimization.
Jiaming He received the M.S. and Ph.D. degrees
from Zhejiang University, Hangzhou, China, in 1993
and 1996, respectively.
He is currently a Professor with Ningbo Univer-
sity, Zhejiang, China. His research interests include
broadband wireless communication systems.
Chadi Assi (SM’08) received the B.Eng. degree
from the Lebanese University, Beirut, Lebanon, in
1997 and the Ph.D. degree from the City University
of New York (CUNY), New York, NY, USA, in
2003.
He is currently a Full Professor with the Concor-
dia Institute for Information Systems Engineering,
Concordia University, Montreal, QC, Canada. Be-
fore joining Concordia University, he was a Visiting
Researcher with Nokia Research Center, Boston,
MA, USA, where he worked on quality of service in
passive optical access networks. His main research interests include networks
and network design and optimization. His current research interests include
network design and optimization, network modeling, and network reliability.
Dr. Assi is on the Editorial Board of the IEEE COMMUNICATIONS SUR-
VEYS AND TUTORIALS, IEEE TRANSACTIONS ON COMMUNICATIONS, and
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY. He was a recipient of
the prestigious Mina Rees Dissertation Award from CUNY in August 2002 for
his research on wavelength-division multiplexing optical networks.