自组织网络中UPMA协议的群间仿真

基于有效竞争预约接入、无冲突轮询传输的思想,结合分层分布式网络结构为自组织网络提出了依据用户妥善安排的多址接入(UPMA)协议,UPMA协议可以支持节点移动性和多跳网络拓扑,并使用网络仿真工具OPNET仿真评估了它的群间通信性能.该协议利用分群算法将多跳网络拓扑形成轮询所需要的两跳分群结构,包括预约接入和无冲突的轮询服务阶段.有分组发送的节点在每帧的竞争接入时隙中竞争接入.如果成功,则进入轮询服务过程;否则,在本帧重新开始的接入阶段中进行冲突避免和分解的预约接入过程.仿真结果表明,UPMA协议显著提高了多跳群间的业务传输效率,可以提供较高的端到端信道利用率、较低的端到端平均消息时延和较小的平均消息丢弃率.

Intercluster simulation of UPMA protocol for self-organizing networks

Based on the concept of contention reservation,polling transmission and combining distributed clustering network architecture,an user-dependent perfect-scheduling multiple access(UPMA) protocol for supporting node mobility and multihop architecture in wireless self-organizing networks was described,and its performance of intercluster communication was simulated by OPNET.By clustering algorithms,two-hop cluster architecture for polling mechanism was formed to support multihop network topology.The protocol includes reservation access phase and polling phase in channel period.In the protocol,the nodes with packets to send contend to reserve channel resources during access slots of every frame.If successful,they were polled to transmit their packets in subsequent frames.If not,collision avoidance and resolution process was used for efficient access.The simulation results show that the proposed protocol can greatly improve multihop transmission efficiency,and achieve higher end-to-end channel utilization,lower average end-to-end message delay and less average message dropping rate.