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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.compeleceng.2010.02.003 Byline: Imam Al-wazedi, Ahmed K. Elhakeem Keywords: WCDMA; TDMA; TDD; Mesh networks Abstract: Wide band mesh or star oriented networks have recently become a subject of greater interest. Providing wideband multimedia access for a variety of applications has led to the inception of mesh networks. Classic access techniques such as FDMA and TDMA have been the norm for such networks. CDMA maximum transmitter power is much less than TDMA and FDMA counter parts, which is an important asset for mobile operation. In this paper we introduce a code division multiple access/time division duplex technique CDMA/TDD for such networks. The CDMA approach is an almost play and plug technology for wireless access, making it amenable for implementation by the mesh network service station, SS. Further it inherently allows mesh network service stations to use a combination of turbo coding and dynamic parallel orthogonal transmission to improve network efficiency. We outline briefly the new transmitter and receiver structures then evaluate the efficiency, delay and delay jitter. By analysis we show the advantages over classic counter parts with respect to the total network efficiency achievable especially for larger number of hops. Author Affiliation: Department of ECE, Concordia University, Montreal, Quebec, Canada Article History: Received 1 April 2009; Revised 31 October 2009; Accepted 5 February 2010 Article Note: (footnote) [star] Reviews processed and proposed for publication to the Editor-in-Chief by Associate Editor Dr. A. El-Osery.

A new congestion control scheme is analyzed for an ATM multiplexer node. This scheme is based on the leaky bucket and virtual leaky bucket techniques, and utilizes the interaction between the ATM and higher layers, in a hybrid asynchronous transfer mode/time division multiple access (ATM/TDMA) network. The transport users are assumed to be generic ATM sources, who modulate their end-to-end flow control parameters, i.e. protocol data unit size in case of video and voice users, and window size in case of data users, based on the congestion status. Simple analytical formulas are derived for congestion criteria, to represent the required bandwidth to support various classes of service, i.e. video, voice, data, etc. with their own performance requirements. An ATM multiplexer node buffer is analyzed using a modulated poisson process queuing model with bulk arrival and bulk service of cells. The ATM multiplexer node congestion performance criteria, i.e. the mean probabilities of ATM multiplexer node congestion, cell generation, cell discarding, buffer content and buffer overflow, are evaluated with and without the congestion control schemes. Key words: Asynchronous transfer mode, time division multiple access, ATM multiplexer node, admission control, leaky bucket, virtual leaky bucket, congestion control, bandwidth, protocol data unit, quality of service.