车载网中保证服务质量的混合信道访问控制优化策略

Qo S Guaranteed HCCA Scheme Optimization in VANET (Vehicular Ad-hoc Network)

在车载网中,为了保证数据传输的服务质量,一个稳定高效的信道访问策略是十分必要的.据此,在802.11p协议的链路层信道访问控制协议HCCA策略的基础上,提出一种基于马尔科夫决策过程的紧急数据优先的策略(URF-HCCA)来保证数据传输的服务质量.该策略采用按需分配资源的方式来减少系统的传输冗余和传输延迟.此外,它还引入了基于延迟预测的接入控制模型.仿真结果表明,与其他几种策略相比,URF-HCCA优化策略可以很好的满足传输的服务质量需求,提高信道利用率、降低平均传输延迟以及系统的丢包率.

To guarantee data transmission quality of service in VANET environment,a stable channel access scheme is very necessary. This paper proposes an urgent request first HCCA scheme （ URF-HCCAA ） based on Markov Decision Process model in medium access control layer to optimize transmission quality of service. Besides,it also importsan admission control scheme based on delay prediction model. The simulation results show that, comparing with other scheduling schemes, URF-HCCA scheme could better satisfy the quality of service requirements.imorove channel utilitv.decreasethe transmission delay and hacker loss rate.