abled higher data rates for users that have high SINR. A mobile device measures the strength of the signal Broadband Telecommunications Technologies and Management received from a base station, produces a parameter known as the signal quality indicator (SQI), and reports it back to the base station. Based on this parameter, the base station then decides the appropriate transmission rate for that mobile device. A different way of controlling the transmission rate is through the use of different channel coding schemes. The lower the coding rate (e.g. 1/3 or 1/2), the more protection the coding scheme provides to the transmitted data. However this comes at the expense of lower transmission rates, as more redundant bits are added for the purpose of error correction. If the channel is of high quality, then higher cod- ing rates (e.g. 3/4 or 7/8) are sufficient. This results in higher effective data rates. The HSDPA W-CDMA standard specifies an adaptive modulation and coding (AMC) rate. Each AMC rate includes a spreading factor, coding rate and modulation method, the combination of which results in a unique transmission rate. The AMC rate is controlled based on information conveyed through the SQI sent by a mobile device. Most mobile communication technologies until Release 5 of the W-CDMA standard were primarily designed for voice communication. They were based on circuit-switched technology in that a dedicated end-to-end channel was established for a voice call. This was logical because a voice call is a continuous process which fully utilises a circuit when the call is active. In con- trast, data communications use packet switching, which is characterised by periods of active and inactive usage. HSDPA uses packet-switching technology as it is better suited to supporting data communications. In voice communication, the capacity parameter of interest is the maximum number of users that can be accommodated simultaneously. In packet-switched data communications the parameters of interest are the peak transmission rate, 