Some Design Parameters of Wireless Networks to Support Rich Media Applications

Abstract

The wireless networks have been in great demand for providing services requiring audio, video newlinestreaming, and on-demand rich media applications. To provide these kinds of services on mobile newlinedevices, a high capacity downlink is required in cellular system with quality-of-service (QoS) newlineprovisioning. The quality-of-services means acceptable data transfer rate, bit error rate (BER), newlineand signal to noise ratio (SNR). One of the imperatives for improving the quality-of-service newline(QoS) in high-speed networks is to reduce congestion. Congestion occurs when the resource in newlinedemand exceeds the capacity of the network. The present research work analyses the newlineperformance of a robust adaptive congestion control algorithm for available bit rate traffic in newlineAsynchronous Transfer Mode (ATM) networks and proposes an improvement in algorithm for newlinebetter performance. A 25-30% less data rate settling time has been achieved compared to the newlineexisting algorithm, resulting in congestion control, and improvement of QoS. newlineThe algorithm is made efficient by better management of resources (bandwidth, power) in newlinewireless networks. The orthogonal frequency division multiple access (OFDMA) system, which newlineis an efficient modulation and multiple access method used for next generation wireless newlinecommunication systems fulfills the above requirements. The communication systems support newlinedifferent types of users. Some users require on-demand services, real time applications and some newlineusers have other kinds of needs, where lesser resources and speed is desired. The main issue in newlineOFDMA systems is the allocation of sub-carriers and power among different types of users. In newlinethis thesis, several adaptive resource allocation algorithms for OFDMA system are analysed and newlinean algorithm that is sensitive to the requirements of different categories of users is proposed.