一种支持单向链路的PUMA改进组播路由协议

摘要

Studies show that asymmetric and unidirectional links are common in MANETs.However,most routing protocols are designed for bidirectional links.Therefore,we present an improved routing for unidirectional links (PUMAUD),a multicast routing protocol that collects information about the unidirectional links on a path to make routing decisions.The collected information can furthermore be used for more effective neighborhood management and better communication quality.We adopted NS2 to simulate PUMA-UD and compared with the original PUMA (Protocol for Unified Multicasting through Announcement) and FLOOD in the same scene with unidirectional links.Simulated results indicate that PUMA-UD is superior to PUMA and FLOOD in packet delivery rate and end-to-end delay when network load increases.%研究表明在无线自组网场景中通常存在非对称、单向链路,但是目前大部分路由协议都是针对双向链路设计的.故针对单向链路问题,提出改进的组播路由算法PUMA-UD,收集单向链路信息进行路由选择,这有利于邻域管理且提高通信质量.使用NS2仿真平台进行仿真验证,将改进后的协议与原PUMA和FLOOD进行比较,结果显示当网络负载增大时,PUMA-UD在报文投递率和端到端延时方面优于PUMA和FLOOD.