Safety Message Transmission in Vehicular Communication Networks
Emerging vehicular safety applications require low latency communications and reliable packet dissemination for life saving safety messages. Significant developments have taken place over the past few years. IEEE WAVE and ISO CALM have been developed as international standards for ITS applications. Both WAVE and CALM support multichannel operations and use CSMA/CA as channel access mechanism. WAVE may impose a latency of 54 milliseconds for enabling multi-channel operations. CSMA/CA method can experience unpredictable delay and packet drop when channel is congested.