Ahmed K. Elhakeem

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By most predictions, fourth-generation wireless systems will be composed of heterogeneous networks. Two important constituent networks will be wireless LAN (WLAN) and cellular mobile radio systems (e.g., UMTS). WLAN is designed for low-range, high/medium data rate access and can be used as a complement to larger cellular mobile radio systems. In this paper,(More)
Ongoing technological advances in portable devices, coupled with the need for continuous connectivity while mobile, have made ad-hoc networks a compelling research and development topic. Performance evaluation of the IEEE 802.11’s ad-hoc mode of operation, as a dominating WLAN protocol, requires a thorough investigation, particularly in a multi-hop(More)
A new code synchronization algorithm is proposed in this paper for the secondary cell-search stage in wideband CDMA systems. Rather than using the Cyclically Permutable (CP) code in the Secondary Synchronization Channel (S-SCH) to simultaneously determine the frame boundary and scrambling code group, the new synchronization algorithm implements the same(More)
Multicasting has become increasingly important with the emergence of Internet-based applications such as IP telephony, audio/video conferencing, distributed databases and software upgrading. IP multicasting is an efficient way to distribute information from a single source to multiple destinations at different locations. In practice IP is considered as a(More)
Abstract--The expected number of retransmissions is a very important parameter to evaluate the multicast performance. It is often used to estimate other performance parameters such as the bandwidth consumption and delay. A simple and efficient evaluation to these parameters is helpful for design of multicast protocols. In this work, we will derive a good(More)