Short paper: A LTE-direct broadcast mechanism for periodic vehicular safety communications

LTE-Direct is an upcoming LTE rel. 12 extension to allow UEs to communicate directly without going through an eNB. LTE-Direct is expected to be used in future LTE-A networks for unicast Proximity Services, and has not been envisioned so far for broadcast transmissions. In this paper, we propose an eMBMS-inspired mechanism to allocate LTE-Direct resources for dedicated broadcast/multicast vehicular safety communications. The mechanism does not require any connection procedure for LTE-Direct broadcast transmissions, and proposes to reserve identical LTE downlink resources over multiple eNB for dedicated communications between UEs. We apply this concept to the periodic broadcast of BSM/CAM and illustrate that the mechanism´s flexibility and extensibility makes LTE-Direct a good complementary technology to DSRC for periodic vehicular safety communications.