Link adaptation and power control for streaming services in EGPRS wirelessnetworks

Using the MPEG-4 advanced audio coder (AAC) music as an example of streamin g applications, we investigate the improvement of error performance for the streaming service by link-adaptation and power-control techniques in an en hanced general packet radio services (EGPRS) cellular network. A low packet error rate and variability are essential in providing a short error-burst length so that error concealment techniques can be effectively applied to m usic packets. In this paper, we study the effects of a combined link adapta tion and power control scheme (referred to as the error-based scheme) for a chieving a target error rate and reducing error variability. By simulation, we compare the error performance of the error-based scheme at both the EGP RS block and AAC frame level with another adaptation algorithm (referred to as the throughput-based scheme) with a goal of maximizing overall network throughput. It is found that when offered with a similar traffic load, the former scheme can provide noticeable improvement of music quality over the throughput-based scheme. To achieve a similar AAC frame error rate, our res ults also show that the error-based scheme can increase the link throughput over the throughput-based scheme by 66.7% in one of our examples. These re sults reveal that by aiming at required error targets and thus reducing err or variability, the error-based scheme for link adaptation and power contro l are helpful in improving quality and capacity for streaming applications.