基于反馈方式的车辆间合作下载方法研究

车联网中基于商业数据内容服务的下载越来越受到重视,如车载办公（office-on-wheels）和车载娱乐（entertainment-on-wheels）.由于路边接入点AP（access point）在道路上分布稀疏相互间隔较远（一般间隔几公里以上）,通过V2I（vehicle-to-infrastructure）车辆到路边接入点的通信下载一直处于一种断断续续的情况.考虑到地理位置相近的车辆可以形成“车辆簇”,文中提出了一种基于反馈方法的簇内车辆合作进行文件下载的机制,分析推导了该方法下载完整个文件所需循环次数的概率分布和均值.最后仿真验证了理论推导分析的正确性,与基于随机方式的车辆合作下载对比大大缩短了单个车辆下载文件的时间.

Feedback-Based Collaborative Downloading Method in VANET

In VANET,commercial data service based data downloading,such as office-on-wheels and entertainment-on-wheels,is getting more and more attention.As roadside access points （APs） are sparsely spread out and are about a few kilometers apart from each other,the file downloading through vehicle-to-infrastructure（V2I） is intermittent.Considering that the geographical proximity of vehicles can form a ＇vehicle cluster＇,a feedback based cooperative downloading method among in-cluster vehicles is proposed for file downloading.The probability distribution and the mean values of the numbers of cycles needed in downloading the whole file are deduced.The simulation verifies the correctness of the theoretical analysis.Compared with random-based collaborative downloading,the proposed scheme can reduce the downloading time.