Master of Engineering

Traffic Prediction Based Access Control Using Different Video Traffic Models in 3G CDMA High Speed Data Newtworks In Proceeding of the 2006 international Conference on Communications and Mobile Computing (Vancouver, British Columbia, Canada, July 03 – 06, 2006). IWCMC ’06. ACM Press

The evolution of 3G Code Division Multiple Access (CDMA) network towards higher data rates is through the introduction of High Speed Downlink Packet Access (HSDPA) enhancement to the existing 3rd Generation Partnership Project (3GPP) standards. In this paper, an access control protocol is proposed for an integrated voice, video and non real-time data traffic on the forward link (cell-site to mobile). The protocol involves predicting the residual capacity available for the HSDPA traffic. This paper evaluates the performance of three video traffic models in predicting the number of data packets that could be scheduled at the next time slot. All three video traffic models exploit the frame properties of Motion Picture Experts Group (MPEG) traffic. The traffic models are based on Markovian, Autogressive (AR) and two-sided Markov Renewal Model (TSMR) processes. The performances of the proposed estimation schemes are compared with estimation scheme using static guard margin. Findings of this paper can be used to improve the downlink performance of non-real time data traffic in the presence of MPEG video traffic in 3G CDMA networks.

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Forward Error Control in Wireless Local Area Networks

In this project, we investigate the performance improvement of applying the Forward Error Control (FEC) to the IEEE 802.11b Wireless LAN standard. In the IEEE 802.11b standard, bit error introduced by the channel noise is protected by Cyclic Redundancy Check (CRC) and results in packet loss. Reliable end-to-end connection is provided by higher layer protocols such as TCP, whose performance is severely degraded by the bit error rate in the channel. We evaluate the performance of two different approaches of FEC implementation, Reed Solomon code, and Turbo code over TCP Wireless LAN. From the OPNET simulations, we concluded that both implementations reduce the packet loss and the congestion in the network.

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