网络编码被认为是改善网络性能的新兴技术。在车联网 VANETs 中，带宽被认为是最重要的网络资源。为此，利用网络编码技术提高 VANETs 中非安全应用的带宽利用率。当两个源节点同时向同一区域广播数据时，转发节点( Relay )就利用网络编码技术降低重播次数和带宽消耗。当转发节点 Relay 接收到数据包时，它有两个选择：等待编码机会，节省带宽；或直接发送数据包，降低时延。针对这两个选择，提出了两个不同的时延控制方案，分别命名为缓冲区域控制方案 BSCS 和时间控制方案 TCS ，用于降低数据包每一跳的时延和提高带宽利用率。仿真结果表明，两个方案能较好地控制时延，且带宽利用率提高了38%。%Network coding is an emerging technique known to improve the network performance in many aspects . In Vehicular Ad-hoc Networks ( VANET ) , the bandwidth is considered to be one of the most important network resources . This paper proposes a net-work coding technique to improve the bandwidth utilization for non-safety applications in VANET . In a scenario where there are two sources broadcasting the data into the same area at the same time , the relay will use the network coding technique to decrease the number of rebroadcasting events and the consumption of the bandwidth . However , a fundamental problem for the relay when it receives a packet , is whether to wait for a coding opportunity and save the bandwidth or send the packet directly and reduce the delay . In order to address such tradeoff , we introduce two versions of our protocol , named buffer size control scheme ( BSCS ) and time control scheme ( TCS ) . By both versions we aim to control the delay that is experienced by the packet at each hop , while achieving better bandwidth utilization . Up to 38% improvement in the bandwidth utilization has been recorded , and both schemes have shown a considerable amount of control on the imposed delay .
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