Performance evaluation of channel access protocols in overlapping ECMA-368 Wireless Personal Area Networks

Medium Access Control (MAC) protocols for Wireless Local Area Networks (WLANs) as well as Wireless Personal Area Networks (WPANs) like Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) are known to provide stable distributed channel access for multiple users. The wide acceptance of wireless systems operating in licensed-exempt frequencies demands for efficient spectrum usage of the scarce radio resources. In partially overlapping network scenarios where channel reuse becomes possible, the non-deterministic behavior prevents random access protocols from exploiting substantial reuse gain. This paper studies the performance of the Distributed Reservation Protocol (DRP) and the Prioritized Contention Access (PCA), a CSMA/CA Protocol, as specified in the Ultra Wideband (UWB) standard ECMA-368. The focus is in particular on channel reuse efficiency and the given result motivates to use DRP to substantial improve spectrum efficiency in scenarios, where a minimal reuse distance is desired. It is shown, that a gain of more than 50% is attained due to the deterministic channel access of DRP in comparison to PCA in partially overlapping network scenarios.