Analytic approximation of the effective bandwidth for best-effort services in UMTS networks

The introduction of third generation mobile communication systems allows the service providers to offer a large variety of services which are in the Universal Mobile Telecommunication System subsumed under the categories conversational, streaming, interactive and background class. While the conversational and streaming classes have a guaranteed bandwidth and delay, the interactive and background class consume the remaining system capacity. On the downlink this system capacity is limited by the base station transmit power and on the uplink by the interference. In our analysis we approximate the capacity which the services with quality of service leave for best-effort services belonging to the interactive class. The background class is neglected. We focus our analysis on the downlink since for UMTS the expected traffic is assumed to be asymmetric with the bulk of it towards the mobile station and derive the distribution of the bandwidth available for best-effort users according to a spatial user distribution.