Sensitivity of service coverage evaluation for WCDMA systems

A fundamental problem in third generation WCDMA network design is that of evaluating user service coverage and resource utilisation, or load, that a trial/candidate network design can sustain. A network design constitutes base station location and infrastructure configuration. It is convention to evaluate network designs using a range of traffic snapshots, each representing a different static geographical distribution of users with particular requests for heterogeneous services. However service coverage evaluation in WCDMA systems is non-trivial because per-link power allocations are required in response to interference from the power allocated to other users. We investigate the sensitivity of two fundamental variables associated with snapshot evaluation-priorities for admission and the mix of requested services. This is carried out in detail for the downlink scenario using a highly efficient offline evaluation technique that avoids recourse to lengthy simulation of online system power control. The results expose the significant influence that the variables have on the resultant evaluation of a candidate network design using a single traffic snapshot. This is important knowledge for network planning.