Radio resource management schemes for combined GSM/GPRS mobile systems

Data services like Web browsing, e-mail and file transfer are becoming more and more popular in cellular systems. In contemporary systems like Global System for Mobile communications (GSM), data transfer has been circuit-switched, that is, physical resources are allocated to a user for the entire call/session duration. However, this is inefficient in case of bursty traffic, where bursts are separated by long intervals of inactivity. This has been the main reason for the introduction of General Packet Radio Service (GPRS), which on the one hand acts as a mobile access network to the Internet, while on the other hand it enables the operator to offer a wide variety of value-added services [Wireless Access Protocol (WAP) over GPRS, e/m-banking, aft-commerce, push services, etc.] efficiently. However, in contemporary commercial implementations of GPRS the radio resource allocation algorithm does not take into account the Quality of Service (QoS)-related service characteristics-although such information is exchanged between the terminal and the network-and consequently all service requests are treated the same way (`best effort'). In this paper, we propose and evaluate via a simulation platform various Radio Resource Management (RRM) schemes capable of differentiating the handling of `service requests' (in uplink and downlink), taking into account the GPRS-related QoS parameters (precedence, reliability, delay, mean and peak throughput). The evaluation is performed for a range of voice (circuit-switched) traffic loads, number of Transmit Receive eXchange (TRXs), offered data (packet-switched) services characteristics, number of dedicated Packet Data Channels (PDCHs), and so on, taking into account the respective QoS requirements for both service types (circuit- and packet-switched). Copyright (C) 2003 John Wiley Sons, Ltd.