MUPF: Multiple unicast path forwarding in content-centric VANETs

Abstract

Vehicular ad-hoc networks (VANETs) with traditional TCP/IP architecture cannot manage mobile nodes effectively. Inspired by information-centric networking (ICN), content-centric VANETs have emerged as a promising architecture to address the challenges of traditional IP-based communications in VANETs. However, several issues need to be solved with regard to this architecture. Among them, inflexible routing schemata based on IP addresses, inefficient traffic caused by network broadcast, and volatility in the network environment cause low network performance in VANETs. By focusing on the content routing of the VANETs, we propose a multiple unicast path-forwarding scheme, MUPF, in which we aim to build multiple stable unicast forwarding paths in content-centric VANETs. The main design concepts of MUPF are as follows: (1) By introducing the idea of ICN, we avoid using the fixed-communication “host-to-host” method employed in IP; MUPF applies a content-centric routing process to request for and reply to packets. (2) We have evaluated the often-occurring broadcast in VANETs, which is thought to have a bad impact on network performance; hence, MUPF uses multiple unicast forwarding paths to deliver the packets instead of a simple broadcast. (3) Considering the highly volatile feature of VANETs, wherein the links are easily broken when the nodes leave, combined with the nodes’ motion parameters and link quality metrics, MUPF can choose some more reliable nodes as next hops to improve the time tolerance of each routing path. In terms of average response time, the performance improvement achieved by MUPF is ∼10%, 15–20%, and 60% compared to CCVN, V-NDN, and TCP/IP, respectively. In terms of the cache-hit ratio, MUPF achieves an improvement of ∼8% and 13.8% over CCVN and V-NDN, respectively; it also decreases network traffic significantly.