摘要
In this paper, we propose an analytical model for the distributed reservation protocol (DRP), which is defined in the WiMedia specification for ultra-wideband (UWB)-based wireless personal area networks (WPANs). We model the tagged user as a discrete-time queue with vacations, which captures the joint behavior of a queue length variation and a time-varying UWB channel due to shadowing under a given reservation pattern. Furthermore, we consider two reservation methods: hard reservation and soft reservation. With the hard reservation, a time slot is exclusively used by the owner, whereas the unused time slots can be accessed by other users using the soft reservation. Closed-form expressions of important performance metrics such as the mean service time, the waiting time, and the throughput are derived. Through numerical results, we validate the accuracy of the proposed analytical model and investigate the interaction between the DRP and various system parameters. This paper should provide insights into the performance of the DRP and useful guidelines to further improve the protocol to support isochronous applications with a tight delay requirement in UWB-based WPANs. © 2009 IEEE.