Bandwidth Allocation and Recovery for Uplink Access in IEEE 802.16 Broadband Wireless Networks

IEEE 802.16 was created to meet the need of highspeed wireless access in metropolitan-scale areas. Due to air interference and dynamic queue state changes in subscriber stations, the idling UL-subframe problem, uplink hole problem, and padding waste problem are inevitable in 802.16 point-to- multipoint networks. To the best of our knowledge, this is the first work that seriously studies these issues. In this paper, we proposed the UBAR protocol, which employs the proportionally fair sharing scheme to utilize bandwidth efficiently, and adopts the timeout-based UL-MAP retransmission scheme with uplink bandwidth reallocation algorithms to simultaneously solve three bandwidth waste problems. Simulation results reveal that the uplink good put of UBAR in error-prone environments can be very close to that in an error-free environment.