为降低通信冲突和信道干扰,对Mult-i Radio Mult-i Channel传感器网络无冲突信道进行研究,结果证实在网络通信半径大于3倍的网络最大功率通信半径的前提下,Sensor节点规模满足2倍网络功率级数加1的环境下,网络无冲突信道分配的信道数达...为降低通信冲突和信道干扰,对Mult-i Radio Mult-i Channel传感器网络无冲突信道进行研究,结果证实在网络通信半径大于3倍的网络最大功率通信半径的前提下,Sensor节点规模满足2倍网络功率级数加1的环境下,网络无冲突信道分配的信道数达到网络信道冲突图的最大值。文章通过对无冲突信道算法的运用,最终证实其可以有效地提高传感器网络的工作效率,大幅度提升网络的吞吐量。展开更多
To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer ro...To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer routing (JCACR), is presented. Firstly, this paper introduces a new concept called channel utilization percentage (CUP), which is for measuring the contention level of different channels in a node’s neighborhood, and deduces its optimal value for determining whether a channel is overloaded or not. Then, a metric parameter named channel selection metric (CSM) is designed, which actually reffects not only the channel status but also corresponding node’s capacity to seize it. JCACR evaluates channel assignment by CSM, performs a local optimization by assigning each node a channel with the smaller CSM value, and changes the working channel dynamically when the channel is overloaded. Therefore, the network load balancing can be achieved. In addition, simulation shows that, when compared with the protocol of weighted cumulative expected transfer time (WCETT), the new protocol can improve the network throughput and reduce the end-to-end average delay with fewer overheads.展开更多
Improving capacity and reducing delay are the most challenging topics in wireless ad hoc networks. Nodes that equip multiple radios working on different channels simultaneously permit ef-fective utility of frequency s...Improving capacity and reducing delay are the most challenging topics in wireless ad hoc networks. Nodes that equip multiple radios working on different channels simultaneously permit ef-fective utility of frequency spectrum and can also reduce interference. In this paper, after analyzing several current protocols in Multi-Radio Multi-Channel (MR-MC) ad hoc networks, a new multi-channel routing metric called Integrative Route Metric (IRM) is designed. It takes channel load, inter-flow, and intra-flow interference into consideration. In addition, an MR-MC routing protocol based on Interference-Aware and Channel-Load (MR-IACL) is also presented. The MR-IACL can assign channels and routings for nodes according to channel load and interference degree of links, and optimize channel distribution dynamically to satisfy the features of topology changing and traffic frequent fluctuation during network running. The simulation results show that the new protocol outperforms others in terms of network throughput, end-to-end delay, routing overhead, and network lifetime.展开更多
A channel assignment algorithm with awareness of link traffic is proposed in multi-radio multi-channel wireless mesh networks. First, the physical interference model based on the signal-to-interference-plus-noise rati...A channel assignment algorithm with awareness of link traffic is proposed in multi-radio multi-channel wireless mesh networks. First, the physical interference model based on the signal-to-interference-plus-noise ratio and successful transmission condition is described. The model is more suitable for a wireless communication environment than other existing models. Secondly, a pure integer quadratic programming (PIQP) model is used to solve the channel assignment problem and improve the capacity of wireless mesh networks. Consequently, a traffic- aware static channel assignment algorithm(TASC) is designed. The algorithm adopts some network parameters, including the network connectivity, the limitation of the number of radios and the successful transmission conditions in wireless communications. The TASC algorithm can diminish network interference and increase the efficiency of channel assignment while keeping the connectivity of the network. Finally, the feasibility and effectivity of the channel assignment solution are illustrated by the simulation results. Compared witb similar algorithms, the proposed algorithm can increase the capacity of WMNs.展开更多
The multi-radio multi-channel wireless mesh network (MRMC-WMN) draws general attention because of its excellent throughput performance, robustness and relative low cost. The closed interactions among power control ...The multi-radio multi-channel wireless mesh network (MRMC-WMN) draws general attention because of its excellent throughput performance, robustness and relative low cost. The closed interactions among power control (PC), channel assignment (CA) and routing is contributed to the performance of multi-radio multi-channel wireless mesh networks (MRMC-WMNs). However, the joint PC, CA and routing (JPCR) design, desired to achieve a global optimization, was poor addressed. The authors present a routing algorithm joint with PC and CA (JPCRA) to seek the routing, power and channel scheme for each flow, which can improve the fairness performance. Firstly, considering available channels and power levels, the routing metric, called minimum flow rate, is designed based on the physical interference and Shannon channel models. The JPCRA is presented based on the genetic algorithm (GA) with simulated annealing to maximize the minimum flow rate, an non-deterministic polynomial-time hard (NP-Hard) problem. Simulations show the JPCRA obtains better fairness among different flows and higher network throughput.展开更多
Opportunistic Routing (OR) involves multiple forwarding candidates to relay packets by taking advantage of the broadcast nature and multi-user diversity of a wireless medium. Compared with Traditional Routing (TR), OR...Opportunistic Routing (OR) involves multiple forwarding candidates to relay packets by taking advantage of the broadcast nature and multi-user diversity of a wireless medium. Compared with Traditional Routing (TR), OR is more suitable in the case of an unreliable wireless link and can evidently improve the end-to-end throughput of Wireless Mesh Networks (WMNs). In this paper, we focus on OR in Multi-Radio Multi-Channel WMNs (MRMC-WMNs). This problem has not been well examined and is considerably more challenging than the OR in single-radio wireless networks considered in the existing literature. First, we validate the advantage of OR in MRMC-WMNs. Second, we propose Low-complexity Channel Assignment for Opportunistic Routing (LcCAOR), which assigns channels to flows according to the interference state of every node. Third, we implement the LcCOAR in a fully distributed manner. The simulation result shows that compared with OR in Single-Radio Single-Channel WMNs (SRSC-WMNs), the proposed OR can significantly enhance the throughput to 87.11% and 100.3% in grid and tree WMNs, respectively.展开更多
Opportunistic routing (OR) involves multiple candidate forwarders to relay packets by taking advantage of the broadcast nature and multi-user diversity of the wireless medium. Compared with traditional routing (TR...Opportunistic routing (OR) involves multiple candidate forwarders to relay packets by taking advantage of the broadcast nature and multi-user diversity of the wireless medium. Compared with traditional routing (TR), OR is more suitable for the unreliable wireless link, and can evidently improve the end to end throughput. At present, there are many achievements concerning OR in the single radio wireless network. However, the study of OR in multi-radio wireless network stays the beginning stage. To demonstrate the benefit of OR in multi-radio multi-channel network, we propose a new route metric -- multi-channel expected anypath transmission time (MEATT), which exploits the channel diversity and resource of multiple candidate forwarders for OR. Based on the new metric, a distributed Mgorithm named Channel Aware Opportunistic Routing (CAOR) is proposed. The simulation results demonstrate that MEATT improves 1.14 and 1.53 times of the average throughput than existing expected anypath transmission time (EATT)and metric of interference and channel switching cost (MIC) respectively. The average delay of MEATT is 17% and 40% lower than those of EATT, MIC, respectively.展开更多
Providing each node with one or more multi-channel radios offers a promising avenue for enhancing the network capacity by simultaneously exploiting multiple non-overlapping channels through different radio interfaces ...Providing each node with one or more multi-channel radios offers a promising avenue for enhancing the network capacity by simultaneously exploiting multiple non-overlapping channels through different radio interfaces and mitigating interferences through proper channel assignment. However, it is quite challenging to effectively utilize multiple channels and/or multiple radios to maximize throughput capacity. The National Natural Science Foundation of China(NSFC) Project61128005 conducted comprehensive algorithmic-theoretic and queuing-theoretic studies of maximizing wireless networking capacity in multi-channel multi-radio(MC-MR) wireless networks under the protocol interference model and fundamentally advanced the state of the art. In addition, under the notoriously hard physical interference model, this project has taken initial algorithmic studies on maximizing the network capacity, with or without power control. We expect the new techniques and tools developed in this project will have wide applications in capacity planning, resource allocation and sharing, and protocol design for wireless networks, and will serve as the basis for future algorithm developments in wireless networks with advanced features, such as multi-input multi-output(MIMO) wireless networks.展开更多
文摘为降低通信冲突和信道干扰,对Mult-i Radio Mult-i Channel传感器网络无冲突信道进行研究,结果证实在网络通信半径大于3倍的网络最大功率通信半径的前提下,Sensor节点规模满足2倍网络功率级数加1的环境下,网络无冲突信道分配的信道数达到网络信道冲突图的最大值。文章通过对无冲突信道算法的运用,最终证实其可以有效地提高传感器网络的工作效率,大幅度提升网络的吞吐量。
基金supported by the National Natural Science Foundationof China (60873195 61070220)+3 种基金the Natural Science Foundation of Anhui Province (070412049)the Outstanding Young Teacher Foundation of Anhui Higher Education Institutions of China (2009SQRZ167)the Natural Science Foundation of Anhui Higher Education Institutions of China (KJ2009B114)the Open Project Program of Engineering Research Center of Safety Critical Industry Measure and Control Technology (SCIMCT0802)
文摘To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer routing (JCACR), is presented. Firstly, this paper introduces a new concept called channel utilization percentage (CUP), which is for measuring the contention level of different channels in a node’s neighborhood, and deduces its optimal value for determining whether a channel is overloaded or not. Then, a metric parameter named channel selection metric (CSM) is designed, which actually reffects not only the channel status but also corresponding node’s capacity to seize it. JCACR evaluates channel assignment by CSM, performs a local optimization by assigning each node a channel with the smaller CSM value, and changes the working channel dynamically when the channel is overloaded. Therefore, the network load balancing can be achieved. In addition, simulation shows that, when compared with the protocol of weighted cumulative expected transfer time (WCETT), the new protocol can improve the network throughput and reduce the end-to-end average delay with fewer overheads.
基金Supported by the National Natural Science Foundation of China (No. 60873195, No. 61070220)the Research Fund for the Doctoral Program of Higher Education of China (No. 20090111110002)
文摘Improving capacity and reducing delay are the most challenging topics in wireless ad hoc networks. Nodes that equip multiple radios working on different channels simultaneously permit ef-fective utility of frequency spectrum and can also reduce interference. In this paper, after analyzing several current protocols in Multi-Radio Multi-Channel (MR-MC) ad hoc networks, a new multi-channel routing metric called Integrative Route Metric (IRM) is designed. It takes channel load, inter-flow, and intra-flow interference into consideration. In addition, an MR-MC routing protocol based on Interference-Aware and Channel-Load (MR-IACL) is also presented. The MR-IACL can assign channels and routings for nodes according to channel load and interference degree of links, and optimize channel distribution dynamically to satisfy the features of topology changing and traffic frequent fluctuation during network running. The simulation results show that the new protocol outperforms others in terms of network throughput, end-to-end delay, routing overhead, and network lifetime.
基金The National Basic Research Program of China(973Program)(No.2009CB320501)the Natural Science Foundation of Jiangsu Province(No.BK2010414)+1 种基金China Postdoctoral Science Foundation(No.20100480071)Specialized Research Fund for the Doctoral Program of Higher Education(No.20090092120029)
文摘A channel assignment algorithm with awareness of link traffic is proposed in multi-radio multi-channel wireless mesh networks. First, the physical interference model based on the signal-to-interference-plus-noise ratio and successful transmission condition is described. The model is more suitable for a wireless communication environment than other existing models. Secondly, a pure integer quadratic programming (PIQP) model is used to solve the channel assignment problem and improve the capacity of wireless mesh networks. Consequently, a traffic- aware static channel assignment algorithm(TASC) is designed. The algorithm adopts some network parameters, including the network connectivity, the limitation of the number of radios and the successful transmission conditions in wireless communications. The TASC algorithm can diminish network interference and increase the efficiency of channel assignment while keeping the connectivity of the network. Finally, the feasibility and effectivity of the channel assignment solution are illustrated by the simulation results. Compared witb similar algorithms, the proposed algorithm can increase the capacity of WMNs.
基金supported by the National Science and Technology Major Project of (2012ZX03003001-004)the Beijing Higher Education Young Elite Teacher Projectthe National Natural Science Foundation of China (61272516, 61272518 and 61302083)
文摘The multi-radio multi-channel wireless mesh network (MRMC-WMN) draws general attention because of its excellent throughput performance, robustness and relative low cost. The closed interactions among power control (PC), channel assignment (CA) and routing is contributed to the performance of multi-radio multi-channel wireless mesh networks (MRMC-WMNs). However, the joint PC, CA and routing (JPCR) design, desired to achieve a global optimization, was poor addressed. The authors present a routing algorithm joint with PC and CA (JPCRA) to seek the routing, power and channel scheme for each flow, which can improve the fairness performance. Firstly, considering available channels and power levels, the routing metric, called minimum flow rate, is designed based on the physical interference and Shannon channel models. The JPCRA is presented based on the genetic algorithm (GA) with simulated annealing to maximize the minimum flow rate, an non-deterministic polynomial-time hard (NP-Hard) problem. Simulations show the JPCRA obtains better fairness among different flows and higher network throughput.
基金supported by the National Basic Research Program of China (973) under Grant No.2012CB315801 the National Natural Science Foundation of China under Grants No.61003305,No.61173167,No.61173168,No.61070194 the Information Security Industrialization Fund from the National Development&Reform Commission of China (NDRC) under Grant No.NDRC[2009]1886
文摘Opportunistic Routing (OR) involves multiple forwarding candidates to relay packets by taking advantage of the broadcast nature and multi-user diversity of a wireless medium. Compared with Traditional Routing (TR), OR is more suitable in the case of an unreliable wireless link and can evidently improve the end-to-end throughput of Wireless Mesh Networks (WMNs). In this paper, we focus on OR in Multi-Radio Multi-Channel WMNs (MRMC-WMNs). This problem has not been well examined and is considerably more challenging than the OR in single-radio wireless networks considered in the existing literature. First, we validate the advantage of OR in MRMC-WMNs. Second, we propose Low-complexity Channel Assignment for Opportunistic Routing (LcCAOR), which assigns channels to flows according to the interference state of every node. Third, we implement the LcCOAR in a fully distributed manner. The simulation result shows that compared with OR in Single-Radio Single-Channel WMNs (SRSC-WMNs), the proposed OR can significantly enhance the throughput to 87.11% and 100.3% in grid and tree WMNs, respectively.
基金supported by the National Basic Research 973 Program of China under Grant No.2012CB315805the National Natural Science Foundation of China under Grant Nos.61173167,61003305,and 61173168the National Science and Technology Major Project of China under Grant No.2011ZX03002-005-02
文摘Opportunistic routing (OR) involves multiple candidate forwarders to relay packets by taking advantage of the broadcast nature and multi-user diversity of the wireless medium. Compared with traditional routing (TR), OR is more suitable for the unreliable wireless link, and can evidently improve the end to end throughput. At present, there are many achievements concerning OR in the single radio wireless network. However, the study of OR in multi-radio wireless network stays the beginning stage. To demonstrate the benefit of OR in multi-radio multi-channel network, we propose a new route metric -- multi-channel expected anypath transmission time (MEATT), which exploits the channel diversity and resource of multiple candidate forwarders for OR. Based on the new metric, a distributed Mgorithm named Channel Aware Opportunistic Routing (CAOR) is proposed. The simulation results demonstrate that MEATT improves 1.14 and 1.53 times of the average throughput than existing expected anypath transmission time (EATT)and metric of interference and channel switching cost (MIC) respectively. The average delay of MEATT is 17% and 40% lower than those of EATT, MIC, respectively.
基金supported in part by the National Natural Science Foundation of China under Grant No.61128005
文摘Providing each node with one or more multi-channel radios offers a promising avenue for enhancing the network capacity by simultaneously exploiting multiple non-overlapping channels through different radio interfaces and mitigating interferences through proper channel assignment. However, it is quite challenging to effectively utilize multiple channels and/or multiple radios to maximize throughput capacity. The National Natural Science Foundation of China(NSFC) Project61128005 conducted comprehensive algorithmic-theoretic and queuing-theoretic studies of maximizing wireless networking capacity in multi-channel multi-radio(MC-MR) wireless networks under the protocol interference model and fundamentally advanced the state of the art. In addition, under the notoriously hard physical interference model, this project has taken initial algorithmic studies on maximizing the network capacity, with or without power control. We expect the new techniques and tools developed in this project will have wide applications in capacity planning, resource allocation and sharing, and protocol design for wireless networks, and will serve as the basis for future algorithm developments in wireless networks with advanced features, such as multi-input multi-output(MIMO) wireless networks.