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Satellite system can provide a high quality broadband communication services especially in the Internet access and multimedia applications. In order to realize an optimized system design, a novel design concept for broadband multimedia satellite system was proposed from Internet point of view. Based on the design concept a MAC protocol called RA-CFDAMA (random access-combined free/demand assigned...
Spectrum-agile radios, also known as cognitive radios, have a great potential to improve spectrum utilization by enabling dynamic access to the spectrum. A key challenge in operating these radios is how to implement an efficient medium access control (MAC) mechanism that adaptively and efficiently allocates transmission powers and spectrum according to the surrounding environment. In this work, we...
In this paper, we present a novel joint power/channel allocation scheme that uses a distributed pricing strategy to improve the network's performance. According to this scheme, the spectrum allocation problem is modeled as a non-cooperative game. A price-based iterative water-filling (PIWF) algorithm is proposed, which allows users to converge to the Nash Equilibrium (NE). This PIWF algorithm can...
Cognitive radios (CRs) have a great potential to improve spectrum utilization by enabling users to access the spectrum dynamically without disturbing licensed primary radios (PRs). A key challenge in operating these radios as a network is how to implement an efficient medium access control (MAC) mechanism that can adaptively and efficiently allocate transmission powers and spectrum among CRs according...
Improving the network throughput is a primary objective in mobile ad hoc networks (MANETs), which is motivated by the over-conservative nature of the 802.11 standard. Transmission power control (TPC) was proposed for improving spatial reuse and reducing energy consumption in MANETs. Previous TPC protocols either incur extra hardware cost (e.g., require multiple transceivers) or do not fully exploit...
HRPD-A adds new forward and reverse link rates and a forward link multi-user packet capability at the MAC layer. Completed simulations reveal the performance characteristics of this system in the 1.9 GHz frequency band. These characteristics consist of capacities of voice/IP traffic and mixed data and voice/IP traffic. Downlink data traffic models consist of FTP, HTTP (Web browsing), WAP, and video...
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