Analytical Modeling of Wireless Communication Systems

3Safety Message Broadcasting

Transportation safety is one of the most important applications of vehicular networks. Vehicles can communicate information on traffic and road conditions with each other, as well as with fixed network nodes. Examples include warning messages that are generated by approaching emergency vehicles, stopped cars or vehicles stuck in a road tunnel because of an accident [SAF 04]. Typically, safety messages need to be broadcast to all vehicles traveling over a geographical area and need to be delivered with high reliability and minimal delay. It is therefore important to develop protocol solutions that meet such requirements.

In [FÜS 05], an innovative protocol architecture for vehicular ad hoc networks is proposed, which enables high interaction between protocol layers and great flexibility in setting the control parameters. Self-organization and routing in vehicular networks supporting safety applications are addressed in [CHI 02], while solutions at the medium access control (MAC) layer are studied in [XU 04, BOR 02, BOR 04, TOR 04, KOR 04, ZAN 04]. In particular, the works in [BOR 02, TOR 04, KOR 04, ZAN 04] deal with broadcast communications. In [KOR 04], an IEEE 802.11 based scheme is proposed to address the broadcast storm and the hidden terminal problems in urban areas. The use of IEEE 802.11e EDCA scheme for priority access is investigated in [TOR 04], where the authors study through simulation the broadcast reception rate in the presence of different ...