Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overl...Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service(QoS). While the former has recently been investigated, the conflict of QoS restraints and resource optimization remains unsolved. Recent studies have shown that overlay paths can give better latency, loss rate and TCP throughput. In this paper, a multi-dimensional QoS objective model based on the analysis of multiple QoS constraints has been presented, and a routing algorithm to optimise the overlay resource of its nodes and links is then proposed.In fact, the algorithm obtained multiple QoS values using probability theory to achieve the routing according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.展开更多
In this paper, the requirements of routing due to the multimedia applications are briefly discussed. In order to solve the QoS constrained routing effectively and efficiently, the scheme of routing based on Hopfield n...In this paper, the requirements of routing due to the multimedia applications are briefly discussed. In order to solve the QoS constrained routing effectively and efficiently, the scheme of routing based on Hopfield neural network is proposed after the analysis of related work. Then the QoS routing algorithm for unicast based on Hopfield NN is described and the result of emulation is given. At last, multicast QoS routing considerations based on Hopfield NN are proposed.展开更多
Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming in- creasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algor...Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming in- creasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this al- gorithm are less than that of Shortest Path First (SPF) with different delay bound.展开更多
The concept of network centric warfare (NCW) and the distributed equal-node network architecture in NCW are introduced in this paper. The data flow requirement model in NCW is presented. Based on synthetic analysis ...The concept of network centric warfare (NCW) and the distributed equal-node network architecture in NCW are introduced in this paper. The data flow requirement model in NCW is presented. Based on synthetic analysis of network resource, the QOS (Quality of Service) parameters and their characters, the high requirement of real-time synchronization in NCW, the single QOS routing constraint, and the network latency between the detector and weapon control station, are presented. To take an example for 3-node brigade (regiment) level NCW demonstration platform, the algorithm of end-to-end network latency and path information in NCW are presented. The algorithm program based on Server/Client architecture is developed. The optimal path is the link whose latency between the detector and weapon control station is the smallest. This paper solves the key issue and satisfies the needs on network latency in NCW. The study results can be widely applied in the decision of the optimal path which is based on multiple service provision points.展开更多
A wireless ad-hoc network is a self-organized wireless network without fixed or backbone infrastructure. All nodes have routing capability and use peer-to-peer packet transmission or forward packets to other node usin...A wireless ad-hoc network is a self-organized wireless network without fixed or backbone infrastructure. All nodes have routing capability and use peer-to-peer packet transmission or forward packets to other node using multi hop communication. Now days mobile ad-hoc networks are being used for different applications and traffics, so it require quality of service (QoS) support in routing protocol. In this paper, a modified QoS routing protocol using directional antenna has been proposed. High and normal priority can be assigned based on type of traffic. All the nodes in the path used by high priority flow are reserved as high priority flow for that flow and normal priority flow will avoid the paths used by high priority flows. If no disjoint paths are available, there may be two possibilities: Normal priority flows are blocked and other is, normal priority flows are allow using the coupled path with high priority flow. Blocking the normal priority flow, QoS routing protocol improves the performance of high priority flow. This concept may be use in emergency communication. Simulation results show that by assigning the priorities to flows, performance of high priority flows are improved and it will further improved by blocking the normal priority flow.展开更多
A heuristic theoretical optimal routing algorithm (TORA) is presented to achieve the data-gathering structure of location-aided quality of service (QoS) in wireless sensor networks (WSNs). The construction of TO...A heuristic theoretical optimal routing algorithm (TORA) is presented to achieve the data-gathering structure of location-aided quality of service (QoS) in wireless sensor networks (WSNs). The construction of TORA is based on a kind of swarm intelligence (SI) mechanism, i. e. , ant colony optimization. Firstly, the ener- gy-efficient weight is designed based on flow distribution to divide WSNs into different functional regions, so the routing selection can self-adapt asymmetric power configurations with lower latency. Then, the designs of the novel heuristic factor and the pheromone updating rule can endow ant-like agents with the ability of detecting the local networks energy status and approaching the theoretical optimal tree, thus improving the adaptability and en- ergy-efficiency in route building. Simulation results show that compared with some classic routing algorithms, TORA can further minimize the total communication energy cost and enhance the QoS performance with low-de- lay effect under the data-gathering condition.展开更多
In the Internet, a group of replicated servers is commonly used in order to improve the scalability of network service. Anycast service is a new network service that can improve network load distribution and simplify ...In the Internet, a group of replicated servers is commonly used in order to improve the scalability of network service. Anycast service is a new network service that can improve network load distribution and simplify certain applications. In this paper, the authors described a simple anycast service model in the Internet without significant affecting the routing and protocol processing infrastructure that was already in place, and proposed an anycast QoS routing algorithm for this model. The algorithm used randomized method to balance network load and improve its performance. Several new techniques are proposed in the algorithm, first, theminimum hops for each node are used in the algorithm, which are used as metric for computing the probability of possible out links. The metric is pre computed for each node in the network, which can simplify the network complexity and provide the routing process with useful information. Second, randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the delay of the routing path. the authors assess the quality of QoS algorithm in terms of the acceptance ratio on anycast QoS requests, and the simulation results on a variety of network topologies and on various parameters show that the algorithm has good performances and can balance network load effectively.展开更多
The A'Prune quality of service (QoS) routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints, The A'Prune is considered to be one of the practical routing algorithms for inte...The A'Prune quality of service (QoS) routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints, The A'Prune is considered to be one of the practical routing algorithms for intelligent optical networks because of its flexibility in handling many practical constraints, This article gives detailed performance studies of the algorithm through extensive simulation experiments. We found that both the running time and the memory space requirements of the algorithm are large, especially when the network size increases, in this article, we also propose an approach to improving the performance of the A'Prune algorithm. The improvements should make the A'Prune algorithm more attractive for practical use in intelligent optical networks.展开更多
Quality of service (QoS) routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology ch...Quality of service (QoS) routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology changes. The multicast routing problem with multiple QoS constraints is discussed, which may deal with the delay, bandwidth and cost metrics, and describes a network model for researching the ad hoc networks QoS multicast routing problem. It presents a distributed QoS multicast routing protocol (DQMRP). The proof of correctness and complenty analysis of the DQMRP are also given. Simulation results show that the multicast tree optimized by DQMRP is better than other protocols and is fitter for the network situations with frequently changed status and the realtime multimedia application. It is an available approach to multicast routing decision with multiple QoS constraints.展开更多
The unique anywhere, anytime wireless communication support offers, tremendous potential for the next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality of Service (QoS) has been the ever deman...The unique anywhere, anytime wireless communication support offers, tremendous potential for the next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality of Service (QoS) has been the ever demanding task of wireless communication to satisfy the application requirements. Geographical routing employs a greedy forwarding technique to deliver the packets to the destination and to owe the communication void, it fails to render the expected level of QoS. Opportunistic routing technique effectively utilizes the advantages of broadcasting nature of the wireless medium and selects a set of forwarding candidates instead of relying on a greedy node. To improve the efficiency of QoS routing in sparse and highly dynamic network topology, this paper proposes the Void-Aware Position based Opportunistic Routing (VAPOR). The VAPOR maintains 2-hop neighbor information to take a routing decision, but it is limited to 1-hop information when the node density is high. It efficiently balances the storage overhead and communication delay due to void and it increases the network throughput even under a sparse network. To provide a certain assurance level for packet reachability, VAPOR decides the potential forwarders based on the forwarding probability that measures link stability, capacity, and connectivity factor. It adaptively favors a path that avoids frequent link failure and unreliable link usage. By limiting the propagation area of duplicate packets, VAPOR reduces wastage of network resources, and ittakes the advantage of concurrent batch forwarding to avoid further duplication and unnecessary delay.展开更多
To meet the bandwidth requirement for the multicasting data flow in ad hoc networks, a distributed on- demand bandwidth-constrained multicast routing (BCMR) protocol for wireless ad hoc networks is proposed. With th...To meet the bandwidth requirement for the multicasting data flow in ad hoc networks, a distributed on- demand bandwidth-constrained multicast routing (BCMR) protocol for wireless ad hoc networks is proposed. With this protocol, the resource reservation table of each node will record the bandwidth requirements of data flows, which access itself, its neighbor nodes and hidden nodes, and every node calculates the remaining available bandwidth by deducting the bandwidth reserved in the resource reservation table from the total available bandwidth of the node. Moreover, the BCMR searches in a distributed manner for the paths with the shortest delay conditioned by the bandwidth constraint. Simulation results demonstrate the good performance of BCMR in terms of packet delivery reliability and the delay. BCMR can meet the requirements of real time communication and can be used in the multicast applications with low mobility in wireless ad hoc networks.展开更多
This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem b...This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time ap-plications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.展开更多
The multicast routing problem with multiple QoS constraints in networks with uncertain parameters is discussed, and a network model that is suitable to research such QoS multicast routing problem is described. The QMR...The multicast routing problem with multiple QoS constraints in networks with uncertain parameters is discussed, and a network model that is suitable to research such QoS multicast routing problem is described. The QMRGA, a multicast routing policy for Internet, mobile network or other highperformance networks is mainly presented, which is based on the genetic algorithm(GA), and can provide QoSsensitive paths in a scalable and flexible way in the network environment with uncertain parameters. The QMRGA can also optimize the network resources such as bandwidth and delay, and can converge to the optimal or nearoptimal solution within few iterations, even for the network environment with uncertain parameters. The incremental rate of computational cost can be close to a polynomial and is less than exponential rate. The performance measures of the QMRGA are evaluated by using simulations. The results show that QMRGA provides an available approach to QoS multicast routing in network environment with uncertain parameters.展开更多
A QoS routing protocol based on mobility prediction is proposed. The protocol selects the steadiest path based on mobility prediction and QoS requirements on bandwidth, delay, and so forth. The main properties of the ...A QoS routing protocol based on mobility prediction is proposed. The protocol selects the steadiest path based on mobility prediction and QoS requirements on bandwidth, delay, and so forth. The main properties of the protocol as follows. (1) Each node just broadcasts its own information, so the packet is very small and can get to the destination in a very short time. (2) When another path is built for the same QoS requirements, the original path has higher priority. (3) The update messages are reduced by using mobility prediction. (4) Data packets carry the information of link change using piggyback, which is helpful for forecasting the link status more accurately. (5) When source node gets Resource Reserve and reconnect packets at the same time, it selects reconnect packet over Resource Reserve packet. The results of simulation show that the protocol has good network performance with low control overload, and efficiently supports transmitting multimedia with QoS requirements in mobile ad hoc networks.展开更多
An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, whi...An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, which combines ant quantity system (AQS) with ant colony optimization (ACO) that is used in AntNet routing algorithm. In dynamic topology networks, the AMQRA achieves timely optimization for concave metric QoS constraint and fast convergence. The proposed routing algorithm is simulated in Iridium satellite constellation on OPNET. The results show that AMQRA not only outperforms the AntNet in convergence rate in dynamic topology networks but also can optimize concave metric QoS constraint and reasonably allot bandwidth to the load to avoid networks congestion.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61071126the National Science and Technology Major Projects of New Generation Broadband Wireless Mobile Communication Network under Grants No.2010ZX0300400201,No.2010ZX03003-001,No.2010ZX03004-001-01,No.2011ZX03002-001-02
文摘Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service(QoS). While the former has recently been investigated, the conflict of QoS restraints and resource optimization remains unsolved. Recent studies have shown that overlay paths can give better latency, loss rate and TCP throughput. In this paper, a multi-dimensional QoS objective model based on the analysis of multiple QoS constraints has been presented, and a routing algorithm to optimise the overlay resource of its nodes and links is then proposed.In fact, the algorithm obtained multiple QoS values using probability theory to achieve the routing according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.
文摘In this paper, the requirements of routing due to the multimedia applications are briefly discussed. In order to solve the QoS constrained routing effectively and efficiently, the scheme of routing based on Hopfield neural network is proposed after the analysis of related work. Then the QoS routing algorithm for unicast based on Hopfield NN is described and the result of emulation is given. At last, multicast QoS routing considerations based on Hopfield NN are proposed.
基金Supported by the National Natural Science Foundation of China (No.60372013).
文摘Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming in- creasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this al- gorithm are less than that of Shortest Path First (SPF) with different delay bound.
文摘The concept of network centric warfare (NCW) and the distributed equal-node network architecture in NCW are introduced in this paper. The data flow requirement model in NCW is presented. Based on synthetic analysis of network resource, the QOS (Quality of Service) parameters and their characters, the high requirement of real-time synchronization in NCW, the single QOS routing constraint, and the network latency between the detector and weapon control station, are presented. To take an example for 3-node brigade (regiment) level NCW demonstration platform, the algorithm of end-to-end network latency and path information in NCW are presented. The algorithm program based on Server/Client architecture is developed. The optimal path is the link whose latency between the detector and weapon control station is the smallest. This paper solves the key issue and satisfies the needs on network latency in NCW. The study results can be widely applied in the decision of the optimal path which is based on multiple service provision points.
文摘A wireless ad-hoc network is a self-organized wireless network without fixed or backbone infrastructure. All nodes have routing capability and use peer-to-peer packet transmission or forward packets to other node using multi hop communication. Now days mobile ad-hoc networks are being used for different applications and traffics, so it require quality of service (QoS) support in routing protocol. In this paper, a modified QoS routing protocol using directional antenna has been proposed. High and normal priority can be assigned based on type of traffic. All the nodes in the path used by high priority flow are reserved as high priority flow for that flow and normal priority flow will avoid the paths used by high priority flows. If no disjoint paths are available, there may be two possibilities: Normal priority flows are blocked and other is, normal priority flows are allow using the coupled path with high priority flow. Blocking the normal priority flow, QoS routing protocol improves the performance of high priority flow. This concept may be use in emergency communication. Simulation results show that by assigning the priorities to flows, performance of high priority flows are improved and it will further improved by blocking the normal priority flow.
基金Supported by the Foundation of National Natural Science of China(60802005,50803016)the Science Foundation for the Excellent Youth Scholars in East China University of Science and Technology(YH0157127)the Undergraduate Innovational Experimentation Program in East China University of Science andTechnology(X1033)~~
文摘A heuristic theoretical optimal routing algorithm (TORA) is presented to achieve the data-gathering structure of location-aided quality of service (QoS) in wireless sensor networks (WSNs). The construction of TORA is based on a kind of swarm intelligence (SI) mechanism, i. e. , ant colony optimization. Firstly, the ener- gy-efficient weight is designed based on flow distribution to divide WSNs into different functional regions, so the routing selection can self-adapt asymmetric power configurations with lower latency. Then, the designs of the novel heuristic factor and the pheromone updating rule can endow ant-like agents with the ability of detecting the local networks energy status and approaching the theoretical optimal tree, thus improving the adaptability and en- ergy-efficiency in route building. Simulation results show that compared with some classic routing algorithms, TORA can further minimize the total communication energy cost and enhance the QoS performance with low-de- lay effect under the data-gathering condition.
基金TheNationalScienceFundforOverseasDistinguishedYoungScholars (No .6 992 82 0 1)FoundationforUniversityKeyTeacherbytheMinist
文摘In the Internet, a group of replicated servers is commonly used in order to improve the scalability of network service. Anycast service is a new network service that can improve network load distribution and simplify certain applications. In this paper, the authors described a simple anycast service model in the Internet without significant affecting the routing and protocol processing infrastructure that was already in place, and proposed an anycast QoS routing algorithm for this model. The algorithm used randomized method to balance network load and improve its performance. Several new techniques are proposed in the algorithm, first, theminimum hops for each node are used in the algorithm, which are used as metric for computing the probability of possible out links. The metric is pre computed for each node in the network, which can simplify the network complexity and provide the routing process with useful information. Second, randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the delay of the routing path. the authors assess the quality of QoS algorithm in terms of the acceptance ratio on anycast QoS requests, and the simulation results on a variety of network topologies and on various parameters show that the algorithm has good performances and can balance network load effectively.
文摘The A'Prune quality of service (QoS) routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints, The A'Prune is considered to be one of the practical routing algorithms for intelligent optical networks because of its flexibility in handling many practical constraints, This article gives detailed performance studies of the algorithm through extensive simulation experiments. We found that both the running time and the memory space requirements of the algorithm are large, especially when the network size increases, in this article, we also propose an approach to improving the performance of the A'Prune algorithm. The improvements should make the A'Prune algorithm more attractive for practical use in intelligent optical networks.
基金This project was supported by the National Natural Science Foundation of China (60172035 ,90304018) NSF of HubeiProvince (2004ABA014) and Teaching Research Project of Higher Educational Institutions of Hubei Province (20040231)
文摘Quality of service (QoS) routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology changes. The multicast routing problem with multiple QoS constraints is discussed, which may deal with the delay, bandwidth and cost metrics, and describes a network model for researching the ad hoc networks QoS multicast routing problem. It presents a distributed QoS multicast routing protocol (DQMRP). The proof of correctness and complenty analysis of the DQMRP are also given. Simulation results show that the multicast tree optimized by DQMRP is better than other protocols and is fitter for the network situations with frequently changed status and the realtime multimedia application. It is an available approach to multicast routing decision with multiple QoS constraints.
文摘The unique anywhere, anytime wireless communication support offers, tremendous potential for the next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality of Service (QoS) has been the ever demanding task of wireless communication to satisfy the application requirements. Geographical routing employs a greedy forwarding technique to deliver the packets to the destination and to owe the communication void, it fails to render the expected level of QoS. Opportunistic routing technique effectively utilizes the advantages of broadcasting nature of the wireless medium and selects a set of forwarding candidates instead of relying on a greedy node. To improve the efficiency of QoS routing in sparse and highly dynamic network topology, this paper proposes the Void-Aware Position based Opportunistic Routing (VAPOR). The VAPOR maintains 2-hop neighbor information to take a routing decision, but it is limited to 1-hop information when the node density is high. It efficiently balances the storage overhead and communication delay due to void and it increases the network throughput even under a sparse network. To provide a certain assurance level for packet reachability, VAPOR decides the potential forwarders based on the forwarding probability that measures link stability, capacity, and connectivity factor. It adaptively favors a path that avoids frequent link failure and unreliable link usage. By limiting the propagation area of duplicate packets, VAPOR reduces wastage of network resources, and ittakes the advantage of concurrent batch forwarding to avoid further duplication and unnecessary delay.
基金The Natural Science Foundation of Zhejiang Province(No.Y1090232)
文摘To meet the bandwidth requirement for the multicasting data flow in ad hoc networks, a distributed on- demand bandwidth-constrained multicast routing (BCMR) protocol for wireless ad hoc networks is proposed. With this protocol, the resource reservation table of each node will record the bandwidth requirements of data flows, which access itself, its neighbor nodes and hidden nodes, and every node calculates the remaining available bandwidth by deducting the bandwidth reserved in the resource reservation table from the total available bandwidth of the node. Moreover, the BCMR searches in a distributed manner for the paths with the shortest delay conditioned by the bandwidth constraint. Simulation results demonstrate the good performance of BCMR in terms of packet delivery reliability and the delay. BCMR can meet the requirements of real time communication and can be used in the multicast applications with low mobility in wireless ad hoc networks.
文摘This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time ap-plications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.
文摘The multicast routing problem with multiple QoS constraints in networks with uncertain parameters is discussed, and a network model that is suitable to research such QoS multicast routing problem is described. The QMRGA, a multicast routing policy for Internet, mobile network or other highperformance networks is mainly presented, which is based on the genetic algorithm(GA), and can provide QoSsensitive paths in a scalable and flexible way in the network environment with uncertain parameters. The QMRGA can also optimize the network resources such as bandwidth and delay, and can converge to the optimal or nearoptimal solution within few iterations, even for the network environment with uncertain parameters. The incremental rate of computational cost can be close to a polynomial and is less than exponential rate. The performance measures of the QMRGA are evaluated by using simulations. The results show that QMRGA provides an available approach to QoS multicast routing in network environment with uncertain parameters.
基金TheNationalHighTechnologyDevelopment"863"Program(No.2 0 0 1AA112051),TheNationalScienceFundforOverseasDistinguishedYoungScholars (No .6992 82 0 1)
文摘A QoS routing protocol based on mobility prediction is proposed. The protocol selects the steadiest path based on mobility prediction and QoS requirements on bandwidth, delay, and so forth. The main properties of the protocol as follows. (1) Each node just broadcasts its own information, so the packet is very small and can get to the destination in a very short time. (2) When another path is built for the same QoS requirements, the original path has higher priority. (3) The update messages are reduced by using mobility prediction. (4) Data packets carry the information of link change using piggyback, which is helpful for forecasting the link status more accurately. (5) When source node gets Resource Reserve and reconnect packets at the same time, it selects reconnect packet over Resource Reserve packet. The results of simulation show that the protocol has good network performance with low control overload, and efficiently supports transmitting multimedia with QoS requirements in mobile ad hoc networks.
基金the National Natural Science Foundation of China (60532030)
文摘An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, which combines ant quantity system (AQS) with ant colony optimization (ACO) that is used in AntNet routing algorithm. In dynamic topology networks, the AMQRA achieves timely optimization for concave metric QoS constraint and fast convergence. The proposed routing algorithm is simulated in Iridium satellite constellation on OPNET. The results show that AMQRA not only outperforms the AntNet in convergence rate in dynamic topology networks but also can optimize concave metric QoS constraint and reasonably allot bandwidth to the load to avoid networks congestion.