Downlink Dimensioning for the HSDPA Standard

Analytic derivation of downlink dimensioning for a wireless network employing the "High Speed Downlink Packet Access" [HSDPA] standard is presented. This standard is currently being developed by the 3GPP partnership as the next evolution of WCDMA [1], [2]. The approach taken determines the maximum possible cell radius such that the probability of outage at the "worst" location in the covered area will not exceed a preset value under full load condition. When in this condition, all the "Base Stations" [BS] are on the air transmitting data to the corresponding mobiles. This paper makes two reasonable approximations: a) A mobile is always supported by one of the three closest BSs, and b) Interference is contributed only by the three closest BSs. Results are presented in the form of curves derived by numerical integration of integrals derived in the paper. This can straightforwardly be done with a computer program capable of numerical integration.