V2V SYSTEM WITH A HYBRID PHYSICAL LAYER

摘要

A vehicle-to-vehicle (V2V) communication transponder for use in V2V communication, safety and anti-collision systems using a hybrid protocol combining time-division multiplexed access (TDMA), with collision sense multiple access (CSMA) protocol. The TDMA frame is broken into regions, a priority and emergency TDMA region, and a non-priority CSMA region. The sizes of the TDMA regions change dynamically based on demand, with the CSMA region using the remaining time slots. Transponders self-select time slots; selected slots are held until a new time slot selection criteria; all transponders participate in notifying a transponder of a time slot message collision. An inter-transmission guard time may be dynamic based on range. Embodiments are free of MAC and IP addresses. No central authority or road-side equipment (RSU) is required. Embodiments include equipped vehicles and V2V system using the transponder.

主权项

1. A vehicle-to-vehicle (V2V) communication transponder adapted to operated in a first vehicle wherein the transponder is adapted to accept as input a subject vehicle position and a subject vehicle heading, and wherein the transponder is adapted to transmit V2V safety messages comprising: (i) the subject vehicle position; (ii) the subject vehicle heading; and (iii) a subject vehicle speed; wherein the improvement is:
the transponder uses a basic time interval (“frame”) of predetermined duration wherein the frame repeats continuously; wherein the frame comprises n time slots of predetermined duration, enumerated and contiguous; wherein the frame is subdivided into a priority class region comprising contiguous time slots from a first time slot S1 to a last time slot S2; and a non-priority class region comprising contiguous time slots from a first time slot S3 to a last time slot S4; wherein the range S1 to S2 and the range S3 to S4 do not overlap; wherein the transponder transmits only time-critical V2V safety messages in the priority class region; wherein the transponder broadcasts a V2V safety message in a self-selected time slot in the priority class region in every frame; wherein the self-selected time slot is the same time slot for every frame until a new time slot is self-selected by the transponder; wherein the transponder manages message broadcasts in the non-priority class region using CSMA protocol.