A Complete Transmission Acknowledgement Scheme for VANETs

One of the distinct features of a Vehicular Ad Hoc Network (VANET) over a typical Mobile Ad Hoc Network (MANET) is its high processing capability due to no battery constraint. Reliable communication is very important in VANETs for providing safety messages, warning messages and other critical information for driver´s assistance. However, congestion may occur due to continuous acknowledgement for providing reliability. Moreover, nodes might interact with each other for a very short duration of time due to different speeds and direction. Sending acknowledgements instead of actual data during that critical time will cause loss of packets. Realizing such constraints, we propose Complete Transmission Acknowledgement Scheme (CTAS) an efficient acknowledgement scheme that utilizes processing capability of vehicular nodes. In our proposed scheme, an acknowledgement is sent by the receiving node after the complete transmission of all the packets by the sending node. We further analyze the correctness and efficiency properties of the proposed Automatic Repeat reQuest (ARQ) scheme. When compared to present acknowledgement schemes, better throughput and packet delivery ratio is achieved.