Ni, Qiang and Vinel, Alexey and Xiao, Yang and Turlikov, Andrey and Jiang, Tao (2007) Investigation of bandwidth request mechanisms under point-to-multmipomint mode of WiMAX networks. IEEE Communications Magazine, 45 (5). pp. 132-138. ISSN 0163-6804
Full text not available from this repository.Abstract
The WiMAX standard specifies a metropolitan area broadband wireless access air interface. In order to support QoS for multimedia applications, various bandwidth request and scheduling mechanisms are suggested in WiMAX, in which a subscriber station can send request messages to a base station, and the base station can grant or reject the request according to the available radio resources. This article first compares two fundamental bandwidth request mechanisms specified in the standard, random access vs. polling under the point-to-multipoint mode, a mandatory transmission mode. Our results demonstrate that random access outperforms polling when the request rate is low. However, its performance degrades significantly when the channel is congested. Adaptive switching between random access and polling according to load can improve system performance. We also investigate the impact of channel noise on the random access request mechanism.