Impact of Rate Control on the Capacity of an Iub Link: Multiple Service Case

This paper studies the capacity and utilization of the downlink of the Iub interface, which lies between the Radio Network Controlled (RNC) and the base station (NodeB) in a UMTS network. In an earlier work, we presented simulation results that indicate that the Iub link utilization is very low with bursty web browsing data especially if each data user is allowed to peak at 384 Kbps. Thus, we introduced a rate control algorithm by which the MAC layer constrains the peak rate of a user based on current load conditions. In this paper, we extend that study to the case where multiple service classes (64, 128, and 384 Kbps) are multiplexed on the same Iub link.