Ad Hoc网络分层结构中,媒体接入控制(MAC)协议规定了节点共享有限的无线带宽资源,直接影响到Ad Hoc网络的总体性能。介绍了各类MAC协议,以及影响协议性能的关键技术。同时分析了这些关键技术应用于各类MAC协议的优缺点,提出了关键技术...Ad Hoc网络分层结构中,媒体接入控制(MAC)协议规定了节点共享有限的无线带宽资源,直接影响到Ad Hoc网络的总体性能。介绍了各类MAC协议,以及影响协议性能的关键技术。同时分析了这些关键技术应用于各类MAC协议的优缺点,提出了关键技术在工程应用中应当遵循的规则和条件,有助于专用MAC协议研究与设计。展开更多
低压电力线通信(Low Voltage Power Line Carrier Communication,LVPLC)的介质访问控制(Medium Access Control,MAC)协议是影响网络吞吐量的重要因素。针对LVPLC精确人工蛛网网络中由于非对称PLC信道影响而导致吞吐量相对较低的问题,改...低压电力线通信(Low Voltage Power Line Carrier Communication,LVPLC)的介质访问控制(Medium Access Control,MAC)协议是影响网络吞吐量的重要因素。针对LVPLC精确人工蛛网网络中由于非对称PLC信道影响而导致吞吐量相对较低的问题,改进了已有的p-载波侦听多路访问协议(p-persistent Carrier Sense Multiple Access,p-CSMA),提出了一种自适应载波侦听多路访问(Adaptive Carrier Sense Multiple Access,ACSMA)协议来优化有限负载下的吞吐量。该协议可通过动态调整概率,降低了数据包的冲突概率,优化了电力线信道的传输状态,最大限度地提高了吞吐量。仿真实验结果表明,ACSMA显著提升了多种通信状态下的吞吐量。展开更多
This paper proposes a novel adaptive time division vehicular ad-hoc networks. ATSA divides different sets multiple access （TDMA） slot assignment protocol （ATSA） for of time slots according to vehicles moving in op...This paper proposes a novel adaptive time division vehicular ad-hoc networks. ATSA divides different sets multiple access （TDMA） slot assignment protocol （ATSA） for of time slots according to vehicles moving in opposite directions. When a node accesses the networks, it choices a frame length and competes a slot based on its direction and location to communication with the other nodes. Based on the binary tree algorithm, the frame length is dynamically doubled or shortened, and the ratio of two slot sets is adjusted to decrease the probability of transmission collisions. The theoretical analysis proves ATSA protocol can reduce the time delay at least 20% than the media access control protocol for vehicular ad-hoc networks （VeMAC） and 30% than the ad-hoc. The simulation experiment shows that ATSA has a good scalability and the collisions would be reduced about 50% than VeMAC, channel utilization is significantly improved than several existing protocols.展开更多
文摘低压电力线通信(Low Voltage Power Line Carrier Communication,LVPLC)的介质访问控制(Medium Access Control,MAC)协议是影响网络吞吐量的重要因素。针对LVPLC精确人工蛛网网络中由于非对称PLC信道影响而导致吞吐量相对较低的问题,改进了已有的p-载波侦听多路访问协议(p-persistent Carrier Sense Multiple Access,p-CSMA),提出了一种自适应载波侦听多路访问(Adaptive Carrier Sense Multiple Access,ACSMA)协议来优化有限负载下的吞吐量。该协议可通过动态调整概率,降低了数据包的冲突概率,优化了电力线信道的传输状态,最大限度地提高了吞吐量。仿真实验结果表明,ACSMA显著提升了多种通信状态下的吞吐量。
基金supported by the National Natural Science Foundation of China (61202099, 61073180)the National Science and Technology Major Project (2010ZX03006-004)+1 种基金the Science and Technology Project of Henan province (102102210026)Ph.D.Programs Foundation of Henan University of Technology(2009BS021)
文摘This paper proposes a novel adaptive time division vehicular ad-hoc networks. ATSA divides different sets multiple access （TDMA） slot assignment protocol （ATSA） for of time slots according to vehicles moving in opposite directions. When a node accesses the networks, it choices a frame length and competes a slot based on its direction and location to communication with the other nodes. Based on the binary tree algorithm, the frame length is dynamically doubled or shortened, and the ratio of two slot sets is adjusted to decrease the probability of transmission collisions. The theoretical analysis proves ATSA protocol can reduce the time delay at least 20% than the media access control protocol for vehicular ad-hoc networks （VeMAC） and 30% than the ad-hoc. The simulation experiment shows that ATSA has a good scalability and the collisions would be reduced about 50% than VeMAC, channel utilization is significantly improved than several existing protocols.
