Analytical Performance Evaluation of DENM Loss in V2V Sidechannel Communications

This paper presents an analysis of loss of decentralized environmental notification messages (DENMs) in a vehicle-to-vehicle scenario in which DENMs are transferred over subchannels of the sidelink specifically allocated to DENM transmission. A simple but meaningful Markov chain model of DENM generation that captures a major requirement of DENM generation and simultaneously recognizes the potentially bursty nature and correlation in the DENM generation process is presented. DENM loss is determined according to a capture model, and closed-form formulae are presented for state dependent probability mass function of the number of DENMs lost as a function of the system parameters. To the best of our knowledge, mass functions of loss of DENMs have not appeared in the literature to date. It is shown that the stochastic equilibrium loss distribution at a given offered load and number of vehicles is independent of the burstiness of the DENM generation process. Numerical examples show how the correlation coefficient of the number of transmitting vehicles is affected by the expected length of the burst period and the number of vehicles generating DENMs at a fixed level of offered load. It is concluded that stochastic equilibrium loss information is inadequate for traffic engineering for DENM transmission.