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In the Long Term Evolution system, Discontinuous Transmission and Reception (DRX/DTX) has been introduced to extend the terminal battery lifetime. In this paper, we research the power-saving provided by our proposed mechanism and the impact on the system performance under the dynamic scheduling joint the delivery of unicast and E-MBMS services. The simulation results show that this mechanism can increase the user throughput and energy efficiency, as well as maintain fairness among users..

A random periodic spectrum sensing scheme is proposed for cognitive radio networks. The sensing period is extended to a general form as a random variable. A generalized Markov analytical model for sensing period optimization is presented, and the optimal sensing period to maximum rewards generated by the channel is derived. Numerical examples show that sensing period does affect the maximum rewards of the channel, and the analytical model is justified by its analytical flexibility since it uses a general sensing period and hence the model can be easily adapted for the analysis of many different applications.

Disseminating spatial data and delivering GIS functionality via Internet has become common-place. However, building a popular online mapping services system that serving staggering amount of Internet users remains as a challenge. This paper describes the Internet mapping architecture based on cluster technology enhanced by mapping-oriented load balancing algorithm.