Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective ...Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective and reliable to guarantee successful packet delivery.Based on the data delivery structure,most of the existing multicast routing protocols can be classified into two folders:tree-based and mesh-based.We observe that tree-based ones have high forwarding efficiency and low consumptions of bandwidth,and they may have poor robustness because only one link exists between two nodes.As a treebased multicast routing protocol,MAODV(Multicast Ad hoc On-demand Vector) shows an excellent performance in lightweight ad hoc networks.As the load of network increases,QoS(Quality of Service) is degraded obviously.In this paper,we analyze the impact of network load on MAODV protocol,and propose an optimized protocol MAODV-BB(Multicast Ad hoc On-demand Vector with Backup Branches),which improves robustness of the MAODV protocol by combining advantages of the tree structure and the mesh structure.It not only can update shorter tree branches but also construct a multicast tree with backup branches.Mathematical analysis and simulation results both demonstrate that the MAODV-BB protocol improves the network performance over conventional MAODV in heavy load ad hoc networks.展开更多
A new multicast routing algorithm based on the hybrid genetic algorithm (HGA) is proposed. The coding pattern based on the number of routing paths is used. A fitness function that is computed easily and makes algorith...A new multicast routing algorithm based on the hybrid genetic algorithm (HGA) is proposed. The coding pattern based on the number of routing paths is used. A fitness function that is computed easily and makes algorithm quickly convergent is proposed. A new approach that defines the HGA's parameters is provided. The simulation shows that the approach can increase largely the convergent ratio, and the fitting values of the parameters of this algorithm are different from that of the original algorithms. The optimal mutation probability of HGA equals 0.50 in HGA in the experiment, but that equals 0.07 in SGA. It has been concluded that the population size has a significant influence on the HGA's convergent ratio when it's mutation probability is bigger. The algorithm with a small population size has a high average convergent rate. The population size has little influence on HGA with the lower mutation probability.展开更多
The electronic system in a comprehensive shipboard has a extremely wide bandwidth. It supports synchronized and asynchronous data transmission, muhimedia correspondence, and videophone conferencing. In order to guaran...The electronic system in a comprehensive shipboard has a extremely wide bandwidth. It supports synchronized and asynchronous data transmission, muhimedia correspondence, and videophone conferencing. In order to guarantee the security and correspondent real time of the communication, choosing a multicast routing protocol based on different applications is a key problem in terms of the complexity of the system. A simulation model was first designed for existing multicast routing protocols in NS-2 and analysis was performed on their corresponding application environments. The experiments proved that PIM-DM based on the shortest-path tree protocol is suitable for communication in the field of comprehensive shipboard. Further work that is necessary is also discussed.展开更多
A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicas...A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.展开更多
The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the...The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.展开更多
There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-la...There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-layer satellite MPLs networks. It has advantages of saving space and reducing extra charge.展开更多
Providing end-to-end delay guarantees in traditional Internet is a complex task due to the distributed nature of TCP/IP protocols. Software Defined Networking(SDN) gives a new dimension to improve QoS(Quality of Servi...Providing end-to-end delay guarantees in traditional Internet is a complex task due to the distributed nature of TCP/IP protocols. Software Defined Networking(SDN) gives a new dimension to improve QoS(Quality of Service) as it can benefit from its flexibility, programmability and centralized view. In this paper, we provide delay-guaranteed data transmission service instead of "best efforts" service for a topic-based publish/subscribe system by means of exploring these specific features of SDN. We attribute this routing problem in such conditions to Delay-Constraint Lowest Cost Steiner Tree(DCLCST) problem. To solve it, we compute the shortest delay paths from source node to every subscribe node and the shortest cost paths from every subscribe node to any other node using dijkstra algorithm. Then we construct a delay-constraint least cost steiner tree for per-topic based on these paths as multicast tree. We also present experimental results to demonstrate the effectiveness of the algorithms and methods we proposed.展开更多
For the research of mobile Ad hoc network (MANET), hardware in the loop simulation (HILS) is introduced to improve simulation fidelity. The architectures and frameworks of HILS system are discussed. Based on HILS and ...For the research of mobile Ad hoc network (MANET), hardware in the loop simulation (HILS) is introduced to improve simulation fidelity. The architectures and frameworks of HILS system are discussed. Based on HILS and QualNet network simulator, two kinds of simulation frameworks for MANET multicast emergency communication network are proposed. By running simulation under this configuration and doing experiments with on-demand multicast routing protocol (ODMRP), unicast and multicast functions of this protocol are tested. Research results indicate that HILS method can effectively reduce the difficulty of system modeling and improve precision of simulation, and can further accelerate transition from design to system deployment.展开更多
基金This work is supported by the NSFC （National Natural Science Foundation of China） No. 61371068 and No. 61172130, the National 863 program No.2011AA11A102-04-02 and Shenzhen Technology Research and Development Program No. CXZZ20120830100839333.
文摘Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective and reliable to guarantee successful packet delivery.Based on the data delivery structure,most of the existing multicast routing protocols can be classified into two folders:tree-based and mesh-based.We observe that tree-based ones have high forwarding efficiency and low consumptions of bandwidth,and they may have poor robustness because only one link exists between two nodes.As a treebased multicast routing protocol,MAODV(Multicast Ad hoc On-demand Vector) shows an excellent performance in lightweight ad hoc networks.As the load of network increases,QoS(Quality of Service) is degraded obviously.In this paper,we analyze the impact of network load on MAODV protocol,and propose an optimized protocol MAODV-BB(Multicast Ad hoc On-demand Vector with Backup Branches),which improves robustness of the MAODV protocol by combining advantages of the tree structure and the mesh structure.It not only can update shorter tree branches but also construct a multicast tree with backup branches.Mathematical analysis and simulation results both demonstrate that the MAODV-BB protocol improves the network performance over conventional MAODV in heavy load ad hoc networks.
文摘A new multicast routing algorithm based on the hybrid genetic algorithm (HGA) is proposed. The coding pattern based on the number of routing paths is used. A fitness function that is computed easily and makes algorithm quickly convergent is proposed. A new approach that defines the HGA's parameters is provided. The simulation shows that the approach can increase largely the convergent ratio, and the fitting values of the parameters of this algorithm are different from that of the original algorithms. The optimal mutation probability of HGA equals 0.50 in HGA in the experiment, but that equals 0.07 in SGA. It has been concluded that the population size has a significant influence on the HGA's convergent ratio when it's mutation probability is bigger. The algorithm with a small population size has a high average convergent rate. The population size has little influence on HGA with the lower mutation probability.
基金Supported by the Performance Simulation and Computation Complexity on Computer Network Foundation (No.F2004060)
文摘The electronic system in a comprehensive shipboard has a extremely wide bandwidth. It supports synchronized and asynchronous data transmission, muhimedia correspondence, and videophone conferencing. In order to guarantee the security and correspondent real time of the communication, choosing a multicast routing protocol based on different applications is a key problem in terms of the complexity of the system. A simulation model was first designed for existing multicast routing protocols in NS-2 and analysis was performed on their corresponding application environments. The experiments proved that PIM-DM based on the shortest-path tree protocol is suitable for communication in the field of comprehensive shipboard. Further work that is necessary is also discussed.
文摘A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.
文摘The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.
基金National863 Program for High Technique Research Development Project( 2 0 0 2 AA712 0 3 1)
文摘There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-layer satellite MPLs networks. It has advantages of saving space and reducing extra charge.
基金supported in part by the National Natural Science Foundation of China under Grants U1804164, 61902112 and U1404602in part by the Science and Technology Foundation of Henan Educational Committee under Grants 19A510015, 20A520019 and 20A520020the Doctoral Research Project of Henan Normal University under Grant 5101119170149
文摘Providing end-to-end delay guarantees in traditional Internet is a complex task due to the distributed nature of TCP/IP protocols. Software Defined Networking(SDN) gives a new dimension to improve QoS(Quality of Service) as it can benefit from its flexibility, programmability and centralized view. In this paper, we provide delay-guaranteed data transmission service instead of "best efforts" service for a topic-based publish/subscribe system by means of exploring these specific features of SDN. We attribute this routing problem in such conditions to Delay-Constraint Lowest Cost Steiner Tree(DCLCST) problem. To solve it, we compute the shortest delay paths from source node to every subscribe node and the shortest cost paths from every subscribe node to any other node using dijkstra algorithm. Then we construct a delay-constraint least cost steiner tree for per-topic based on these paths as multicast tree. We also present experimental results to demonstrate the effectiveness of the algorithms and methods we proposed.
文摘For the research of mobile Ad hoc network (MANET), hardware in the loop simulation (HILS) is introduced to improve simulation fidelity. The architectures and frameworks of HILS system are discussed. Based on HILS and QualNet network simulator, two kinds of simulation frameworks for MANET multicast emergency communication network are proposed. By running simulation under this configuration and doing experiments with on-demand multicast routing protocol (ODMRP), unicast and multicast functions of this protocol are tested. Research results indicate that HILS method can effectively reduce the difficulty of system modeling and improve precision of simulation, and can further accelerate transition from design to system deployment.
