MAC Efficiency Enhancement with Prioritized Access Opportunity Exchange Protocol for 60 GHz Short-Range One-to-One Communications

This paper proposes a prioritized access opportunity exchange protocol for enhancing medium access control (MAC) efficiency in short-range one-to-one wireless communications on 60 GHz millimeter wave. A random back-off access protocol is widely spread for distributed wireless networks and is adopted in IEEE 802.11 WLAN standard. When many terminals try to access a wireless medium, the protocol works effectively in terms of fairness and throughput. However, when only two terminals try to access the wireless medium, it's overhead becomes large and the MAC efficiency is degraded. In this paper, an access protocol that minimizes the access overhead is proposed for one-to-one communications. In the proposed protocol, a prioritized access opportunity (PAOP) is exchanged between two terminals. A terminal having the PAOP (primary terminal; PT) can access the medium with the minimum period whereas a terminal not having the PAOP (secondary terminal; ST) has to wait the transmission by the PT. If the PT has no data but the ST has data to be transmitted, the PT gives the PAOP to the ST. Then the ST becomes the new PT that accesses the medium with the minimum period. Total throughput and transmission delay performance by the back-off access protocol and by the proposed protocol is evaluated by the computer simulations and the results show the effectiveness of the proposed method.