A multi-channel Beacon Forwarding approach in dual radio Vehicular Ad-Hoc Networks

Dual radios in Vehicular Ad-Hoc Networks (VANETS) enable the usage of multiple communication channels simultaneously. This results in a higher network capacity in contrast to single radio setups. However, using multiple channels simultaneously leads to Adjacent Channel Interference (ACI) by generating noise in nearby channels. This noise increases the packet loss probability and leads to highly unreliable communication channels. In dual radio setups the impact of ACI is significant e.g. if one radio is receiving on the control channel (CCH) while the other radio performs a transmission on a nearby service channel 2 (SCH2). To reduce ACI on CCH, we propose to use a decreased transmit power on SCH2. However, doing so SCH2 suffers from an increased packet loss probability in contrast to CCH and hence is considered to be a highly unreliable communication channel. To utilize SCH2 and even increase the level of awareness for safety critical applications, we introduce a novel multi channel communication approach using Selective Beacon Forwarding (SBF). Our approach is following the service announcement idea of IEEE 1609.3 [4] and applies forwarding of beacons on SCH2 upon request. We evaluate our scheme called Beacon Forwarding as a Service (BFaaS) based on simulations and show that it increases the level of awareness by up to 50% compared to common beaconing strategies.