Design of fast restoration multipath routing in VANETs

Vehicular ad hoc networks (VANETs) using WLAN technology have recently received considerable attention. One of the critical research challenges consists of the design of scalable routing algorithms that are robust to frequent path breakage caused by high mobility of vehicles. In this paper, we propose a multipath routing protocol for VANET named Fast Restoration On-demand Multipath Routing (FROMR). Different from previous researches which emphasize path disjointness, FROMR focuses on rapidly building an alternate path if the original route is broken. In order to reduce the amount of control messages as well as increase the path robustness, FROMR partitions the geographic region into squares of equal-size called grids. Inside each grid, a vehicle which is expected to stay for the longest duration is selected as the grid leader. Only grid leaders are responsible for route discovery, maintenance and restoration. Experimental results show that the proposed FROMR protocols outperform the popular AODV protocol in terms of packet delivery ratio, throughput, route lifetime, and control overhead.