An IP Address Passing Protocol for Vehicular Ad Hoc Networks with Network Fragmentation

• Main Authors: Wei-Han Yi, 易衛漢
• Other Authors: Yuh-Shyan Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/13265671822704477310

碩士 === 國立臺北大學 === 通訊工程研究所 === 98 === The goal of the vehicle mobility management is to effectively reduce handoff delay problem, and keep moving vehicle connecting to the Internet for VANETs. In VANETs, when the vehicles can not continuously communicate with the intended vehicle through directly or multi-hop relays from the vehicle on the lanes of same or opposite direction, network fragmentation occurs. When the vehicle is going to leave the target BS's communication region, the vehicle can not pass IP to next vehicle through existing IP passing protocol because of network fragmentation, so the vehicle can not acquire IP address from the vehicle in front it, when it enters target BS's communication region. In addition, IP acquisition time and network overhead may increase, and create serious handoff delay and packet loss, so the vehicle may break off the real time service, such as VoIP or IPTV. Therefore, how to postpone the time of releasing IP to DHCP server is a very important issue, named IP lifetime. When the network fragmentation occurs, if may cause the handoff latency and packet loss problems, and these problems can lower down the throughput of the network. To overcome these problems, we propose an address passing protocol for VANETs with network fragmentation. In a highway, since each vehicle is moving in a fixed direction at a high speed, our protocol can extend IP lifetime and select a faster way to get its IP address. The vehicle can acquire a new IP address through multi-hop relays from the vehicles on the lanes of the same or opposite direction, and thus reduce handoff delay and maintain the connectivity to the Internet. Simulation results have shown that the proposed scheme is able to reduce IP acquisition time, handoff latency, packet loss rate, and extension of IP lifetime.