The Geo Networking protocol provides single-hop and multi-hop communication in vehicular ad hocnetworks based on IEEE 802.11p/ITS-G5. It has been standardized by the ETSI Technical Committee ITS as part of its Release 1 set of specifications and is expected to be deployed in the next years. This paper presents a performance evaluation of the Geo Networking protocol in its recently published version. Our study assesses the performance of the broadcast forwarding algorithms for multi-hop packet transport that are used to disseminate information in geographical areas for road safety and traffic efficiency applications.
From the algorithms specification in the standard, we derive six variants with different combinations of protocol mechanisms with increasing complexity and assess their performance in terms of reliability, latency, and overhead. The algorithms are evaluated in a reference freeway scenario with bidirectional road traffic and a realistic trace-based mobility model with varying vehicle density. The obtained results indicate that the combination of contention-based and greedy forwarding shows the best overall performance; further functional improvements have a limited performance gain in the studied scenario.