针对公路上路侧单元(road side unit,RSU)部署稀疏且通信范围有限所导致的用户在通信盲区内无法访问Internet的问题,对高速公路场景下的车辆在RSU覆盖区下载数据进行模型研究,文章提出了一种P2P加速传输补偿的协助下载方法。该方法充分...针对公路上路侧单元(road side unit,RSU)部署稀疏且通信范围有限所导致的用户在通信盲区内无法访问Internet的问题,对高速公路场景下的车辆在RSU覆盖区下载数据进行模型研究,文章提出了一种P2P加速传输补偿的协助下载方法。该方法充分利用了车辆间P2P共享传输和协助车辆携带剩余的传输数据来提高系统的吞吐量,并结合数据冗余分配算法协调车辆因车速的不稳定性引起的丢包率过高的问题。仿真结果表明,该方法提高了协助车辆的精确性、传输成功率和速率稳定性,避免过多的选择车辆导致的系统资源浪费;车辆携带冗余数据虽然占用了一些系统资源,但系统容错率相应地得到了补偿性的提高。展开更多
Distributing real-time video stream in large scale group communication over Interuet poses several challenging problems due to the complex network dynamics, stringent requirement of delay and loss. This paper proposes...Distributing real-time video stream in large scale group communication over Interuet poses several challenging problems due to the complex network dynamics, stringent requirement of delay and loss. This paper proposes a novel peer-to-peer scheme, named TeamCast, to combat with these issues. Constructing multiple diverse application layer multicast (ALM) trees to transmit multiple independent complementary descriptions produced by multiple description coding (MDC) simultaneously, TeamCast improves error resilient ability in the presence of various levels of packet loss caused by unpredictable congestion of Internet and node failure, as well as enlarges system capacity. The results of extensive simulations indicate that TeamCast achieves low latency, scalability, and fault tolerance for the delivery of live media stream.展开更多
In order to solve the problem that the existing data scheduling algorithm cannot make full use of neighbors' bandwidth resources when allocating data request among several senders in the multisender based P2P stre...In order to solve the problem that the existing data scheduling algorithm cannot make full use of neighbors' bandwidth resources when allocating data request among several senders in the multisender based P2P streaming system,a peer priority based scheduling algorithm is proposed.The algorithm calculates neighbors' priority based on peers' historical service evaluation as well as how many wanted data that the neighbor has.The data request allocated to each neighbor is adjusted dynamically according to the priority when scheduling.Peers with high priority are preferred to allocate more data request.Experiment shows the algorithm can make full use of neighbors' bandwidth resources to transmit data to reduce server pressure effectively and improve system scalability.展开更多
文摘针对公路上路侧单元(road side unit,RSU)部署稀疏且通信范围有限所导致的用户在通信盲区内无法访问Internet的问题,对高速公路场景下的车辆在RSU覆盖区下载数据进行模型研究,文章提出了一种P2P加速传输补偿的协助下载方法。该方法充分利用了车辆间P2P共享传输和协助车辆携带剩余的传输数据来提高系统的吞吐量,并结合数据冗余分配算法协调车辆因车速的不稳定性引起的丢包率过高的问题。仿真结果表明,该方法提高了协助车辆的精确性、传输成功率和速率稳定性,避免过多的选择车辆导致的系统资源浪费;车辆携带冗余数据虽然占用了一些系统资源,但系统容错率相应地得到了补偿性的提高。
基金Major State Basic Research Development Program of China(973 Program,No.2005CB321903)
文摘Distributing real-time video stream in large scale group communication over Interuet poses several challenging problems due to the complex network dynamics, stringent requirement of delay and loss. This paper proposes a novel peer-to-peer scheme, named TeamCast, to combat with these issues. Constructing multiple diverse application layer multicast (ALM) trees to transmit multiple independent complementary descriptions produced by multiple description coding (MDC) simultaneously, TeamCast improves error resilient ability in the presence of various levels of packet loss caused by unpredictable congestion of Internet and node failure, as well as enlarges system capacity. The results of extensive simulations indicate that TeamCast achieves low latency, scalability, and fault tolerance for the delivery of live media stream.
基金Supported by the National High Technology Research and Development Program of China(No.2009AA01A339,2008AA01A317)the National Natural Science Foundation of China for Distinguished Young Scholars(No.60903218F0208)the Science and Technology Support Plan of China(No.2008BAH28B04)
文摘In order to solve the problem that the existing data scheduling algorithm cannot make full use of neighbors' bandwidth resources when allocating data request among several senders in the multisender based P2P streaming system,a peer priority based scheduling algorithm is proposed.The algorithm calculates neighbors' priority based on peers' historical service evaluation as well as how many wanted data that the neighbor has.The data request allocated to each neighbor is adjusted dynamically according to the priority when scheduling.Peers with high priority are preferred to allocate more data request.Experiment shows the algorithm can make full use of neighbors' bandwidth resources to transmit data to reduce server pressure effectively and improve system scalability.