Cross-layer optimization for CDMA/TDD wireless mesh networks

This paper proposes a new cross-layer optimization algorithm for wireless mesh networks (WMNs). CDMA/TDD (code division multiple access/time division duplex) is utilized and a couple of TDD timeslot scheduling schemes are proposed for the mesh network backbone. Cross-layer optimization involves simultaneous consideration of the signal to interference-plus-noise ratio (SINR) at the physical layer, traffic load estimation and allocation at medium access control (MAC) layer, and routing decision at the network layer. Adaptive antennas are utilized by the wireless mesh routers to take advantage of directional beamforming. The optimization formulation is subject to routing constraints and can be solved by general nonlinear optimization techniques. Comparisons are made with respect to the classic shortest-path routing algorithm in the network layer. The results reveal that the average end-to-end successful packet rate (SPR) can be significantly improved by the cross-layer approach. The corresponding optimized routing decisions are able to reduce the traffic congestion. Copyright (C) 2010 John Wiley & Sons, Ltd.