Ahmed M. Safwat

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SUMMARY In this paper, we propose a new protocol for wireless mobile ad hoc networks, which establishes a dynamic wireless mobile infrastructure. The proposed protocol, namely, the virtual base stations (VBS) protocol, mimics and maintains the operation of the conventional "xed infrastructure in cellular networks. In the VBS protocol, a mobile node is(More)
Relaying is a fundamental concept in multi-hop wireless ad hoc networks whereby communications between mobile terminals are carried out through intermediate nodes. The small distance and the potential high transmission rate between the relaying entities draws our attention to the significance of multi-hop relaying in hot and/or dead spots. Consequently,(More)
In this paper, we propose a new protocol for wireless mobile ad hoc communications, which establishes a dynamic wireless mobile infrastructure to mimic and maintain the operation of the ®xed infrastructure in cellular networks, namely, the Virtual Base Stations (VBS) infrastructure-creation protocol. In the VBS protocol, a mobile station is elected from a(More)
Wireless mobile ad hoc stations have limited battery capacity. Hence, ad hoc routing protocols ought to be energy conservative. However, The simulation studies carried out for table-driven and on-demand ad hoc routing protocols fall short of examining essential power-based performance metrics, such as average node and network lifetime, energy-based protocol(More)
On the contrary to present conjectures, our medium access control (MAC)-based performance studies revealed that battery capacity may not be used as the sole means for achieving energy-based fairness and system longevity for wireless mobile multi-hop ad hoc and sensor networks. Moreover, energy conservation may be attained only if valuable MAC (and PHY)(More)
Using directional antennas in wireless ad hoc networks can significantly improve network performance. However, the deafness problem greatly limits the network performance. This paper thoroughly investigates two types of deafness problems, one of which is reported for the first time in this paper. This paper also proposes a new MAC scheme, namely DMAC-DA, to(More)
We recently devised a novel Ad hoc-Cellular (A-Cell) wireless network architecture consisting of mobile and fixed/conventional base stations and developed efficient mechanisms for routing, DCA, scheduling and CAC [21], [23], [24], [25]. We anticipate that such network architectures and schemes will play a vital role in enhancing future cellular(More)