A Performance Evaluation of PPP Multiplexing Within UTRAN

Abstract

Efficient use of transport resources while minimizing transport delay is important problem within UTRAN because the size of most UTRAN traffic is small compared to the total protocol overheads, and optimization method inevitably introduces delays. AAL2 has been used as a multiplexing scheme to fully exploit fixed-sized ATM cell payload. During the work of 3GPP to introduce IP transport option in UTRAN, PPP Multiplexing (PPPMux) is agreed to be the most efficient solution for this purpose. However, there are relatively small amount of works on the performance of PPPMux in this context. In this paper, we analyze the performance of PPPMux in terms of multiplexing delay and link utilization expressed as average PPPMux frame size. The performance of the scheme is evaluated in various operating conditions considering maximum multiplexing timer, maximum PPPMux frame size, and traffic input rate. The results show that link utilization can be increased while multiplexing delay is tightly bounded below maximum waiting time by using the feature that frame size of PPPMux can vary.