DREAM: IEEE 802.11p/WAVE extended access mode in drive-thru vehicular scenarios

The 802.11p standard has been recently ratified to provide Wireless Access in Vehicular Environments (WAVE). According to the WAVE alternating channel access scheme, singleradio devices must tune into a common frequency during the control channel (CCH) interval, to exchange safety and control packets, and regularly (every 50 ms) switch to one of the available service channels (SCHs) for non-safety data exchange. In order to improve non-safety data delivery performance, the extended access mode has been recently proposed by the standardization groups in order to allow vehicles to stay tuned on the SCH as long as they need before switching on the CCH. In this paper we identify some drive-thru scenarios as possible use cases for the extended access scheme, and propose some enhancements to this scheme with the aim of improving channel utilization and non-safety applications performance without penalizing the delivery of safety messages on the CCH.