Home // International Journal On Advances in Internet Technology, volume 3, numbers 1 and 2, 2010 // View article

The design and implementation of the Cyclic Scheduling Algorithm: A multi-channel MAC protocol

Authors:
Mthulisi Velempini
Mqhele. E. Dlodlo

Keywords: Channel bottleneck, Channel coordination, Channel saturation, Channel selection, Connectivity, Multiple Channel MAC

Abstract:
The realization that single channel MAC protocols do not offer adequate end-to-end throughput has prompted researchers to explore more scalable approaches such as multi-channel MAC protocols. Multi channel MAC protocols implementing a dedicated control channel offer promising solutions. However, it has been suggested that the use of a single control channel may lead to saturation problems. The saturation problem needs to be investigated. The paper proposes a cyclic scheduling algorithm, which schedules data transmission in phases. The scheme reduces the signalling overhead of the control channel and improves its capacity by reducing the effects of the channel switching delay and the idleness of the control channel. The scheme is connection oriented and implements the services of a network support systems, which provides the network with the required intelligence for data channels reservation. The scheme takes advantage of the integration of mesh routers and mesh clients in an overlaid wireless mesh networks (WMN). Mesh routers are also deployed in the ad hoc network of mesh clients to act as a network support backbone. The mesh routers forming the network support backbone are assumed to be within the communication range. We first analyze the control bottleneck problem of the proposed scheme as a channel selection and coordination problem requiring an effective channel scheduling technique. The scheduling techniques should be designed to minimize the effects of channel switching penalty on the control channel. The techniques should also increase the scheduling capacity of control channel. A single dedicated channel with at least two data channels and one transceiver system was considered in the analyses. The capacity of a single control channel is investigated as the number of data channels is increased from two to fourteen. Channel saturation is observed on data channels. Analytical results show that a single dedicated control channel causes no bottlenecks. Its capacity is affected by the saturation of data channels. The proposed scheme was also evaluated through NS 2 simulations. The numerical results show that the scheme is effective in reducing the signalling overhead.

Pages: 29 to 42

Copyright: Copyright (c) to authors, 2010. Used with permission.

Publication date: September 5, 2010

Published in: journal

ISSN: 1942-2652