PERFORMANCE OF PRMA-DR PROTOCOL FOR MULTIMEDIA TRAFFIC

Abstract

The adoption of radio channel access schemes, efficient in supporting multimedia services, is a key issue in the design of future third generation cellular systems. Packet Reservation Multiple Access-Dynamic Reservations (PRMA-DR) is a multiple access protocol_ which explicitly supports multimedia traffic efficiently. Its structure is based on traditional PRMA++ protocol. But in addition to what PRMA++ provides, PRMA-DR provides a flexible dynamic approach in the choice of the percentage of bandwidth to be used for reservations. Separation between reservation and information channels, along with dynamic adaptation of the percentage of reservation bandwidth within a frame to traffic condition, guarantees the required QoS to multimedia services. In this dissertation, the performance of the PRMA-DR multiple access protocol for third generation cellular multimedia communications has been evaluated. For bandwidth allocation it uses a simple technique called Complete Sharing (CS). The base station has a priority based queue. It places the requests in the queue depending upon the priorities, so that QoS is maintained for different traffic classes. For dynamic adaptation of R-slots to traffic load fluctuations, it uses a load-to-Nr (number of reservation slots) look-up table whose figures are a priori evaluated according to a quality metric Q, and a dynamic R-slot adoption algorithm. The PRMA-DR protocol has been simulated using C++ on the Linux platform to evaluate the performance. It is observed that PRMA-DR protocol supports higher channel load that is around 0.85, while maintaining access delay and packet dropping probability within limits.