Medium Access Scheme with Power Control to Improve Performance of FlashLinQ

Device-to-Device (D2D) communications has been considered to reduce heavy traffic load on Base Station (BS) since it enables devices to directly communicate with each other without a relay of BS. Recently, Qualcomm Inc. introduced FlashLinQ (FLQ) for D2D communications, which has a radio frame based on Orthogonal Frequency Division Multiplex (OFDM). In FLQ, D2D User Equipments (DUEs) distributively access to medium based on Signal to Interference Ratio (SIR). When DUEs operate on a real-time service such as Voice over Internet Protocol (VoIP) or File Transfer Protocol (FTP), DUE with low link quality may cause excessive yielding for medium access of other links. Thus, the service requirements of the other links cannot be guaranteed. In order to solve this problem, we propose a medium access scheme including transmission power control for DUEs in FLQ. In the proposed scheme, DUEs determine their transmission power based on the number of neighbor DUEs, and try accessing to medium with the controlled transmission power. Through simulations, we evaluate performance of the proposed scheme by comparing those of the conventional FLQ and Probabilistic Medium Access Scheme (PMAS). We show that the proposed scheme can improve performance of FLQ by simulation results.