Open Access

Opportunistic Nonorthogonal Packet Scheduling in Fixed Broadband Wireless Access Networks

  • Mahmudur Rahman1Email author,
  • Halim Yanikomeroglu1,
  • Mohamed H Ahmed2 and
  • Samy Mahmoud1
EURASIP Journal on Wireless Communications and Networking20062006:080493

DOI: 10.1155/WCN/2006/80493

Received: 14 October 2005

Accepted: 13 March 2006

Published: 18 June 2006


In order to mitigate high cochannel interference resulting from dense channel reuse, the interference management issues are often considered as essential part of scheduling schemes in fixed broadband wireless access (FBWA) networks. To that end, a series of literature has been published recently, in which a group of base stations forms an interferer group (downlink transmissions from each base station become dominant interference for the users in other in-group base stations), and the scheduling scheme deployed in the group allows only one base station to transmit at a time. As a result of time orthogonality in transmissions, the dominant cochannel interferers are prevented, and hence the packet error rate can be improved. However, prohibiting concurrent transmissions in these orthogonal schemes introduces throughput penalty as well as higher end-to-end packet delay which might not be desirable for real-time services. In this paper, we utilize opportunistic nonorthogonality among the in-group transmissions whenever possible and propose a novel transmission scheduling scheme for FBWA networks. The proposed scheme, in contrast to the proactive interference avoidance techniques, strives for the improvements in delay and throughput efficiency. To facilitate opportunistic nonorthogonal transmissions in the interferer group, estimation of signal-to-interference-plus-noise ratio (SINR) is required at the scheduler. We have observed from simulations that the proposed scheme outperforms the reference orthogonal scheme in terms of spectral efficiency, mean packet delay, and packet dropping rate.


Authors’ Affiliations

Communications and Wireless Systems (BCWS) Centre, Department of Systems and Computer Engineering, Carleton University
Faculty of Engineering and Applied Science, Memorial University of Newfoundland


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© Mahmudur Rahman et al. 2006

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.