Measurement-based replanning of cell capacities in GSM networks

Due to the scarcity of the spectral resources and mobility of the portables, the call attempts may be blocked during call initiation or terminated during the hand-off process. When the blocking ratio exceeds some grade of service level, the capacity of the congested cell must be replanned using the call attempt data. However, most of the time, the measurements are inflated by the redials and the retrials. During the replanning process, the first step should be to calculate the effective load from the measured cumulative call statistics. In this paper, we provide simple-to-implement analytical models that compute the average number of retrials and redials per original call attempt using only the operations and maintenance center measurements. The effective load is then determined through appropriate scaling. That way, unnecessary waste of channels to sustain retrials and redials is avoided during the cellular capacity replanning phase.