Dynamic Guard Bandwidth Scheme for Wireless Broadband Networks

−In future wireless broadband networks, bandwidth demands could fluctuate abruptly due to movement of high data rate users. Dynamic bandwidth reservation plays a key role in ensuring that mobile calls are not disrupted after they are admitted into the network. We propose a dynamic guard bandwidth scheme that adapts the amount of guard bandwidth in both wired and wireless links according to real-time handoff predictions made by individual mobile terminals, leveraged by the expected widespread availability of GPS-capable wireless devices in the near future. We describe procedures for approximating irregular handoff-request boundary, and for estimating a mobile's remaining time to handoff and target handoff cell. Guard bandwidth is adjusted on the fly only when a handoff is anticipated to occur shortly. The scheme is robust against modifications in handoff parameters, as well as changes in terrain and manmade features that could affect radio propagation. It also caters for heterogeneous bandwidth requirements. Admission control algorithms for both new calls and handoff calls are provided. Simulation results show that our scheme is able to meet specified forced termination probability under high offered load, and that resources are not reserved unnecessarily.