Applying rapid fluctuation model to analysis of wireless channel utilization in GSM networks

Wireless channel utilization is an important indicator for network capacity and wireless resource usage; it is also the key to network evaluation and optimal assignment of wireless resources in GSM network optimization. A rapid fluctuation model is presented to describe the rapid variation features of the traffic in each cell in networks. On the basis of this model, the cells with similar features of traffic variation are grouped into one class, and all the cells in networks are then precisely clustered into more than one class. It is found by the K-S goodness-of-fit tests that with a particular call blocking probability, the traffic carried by a cell or a class of cells approximately follows the normal distribution. For each cell class, the confidence interval iteration algorithm and the 1-minute-granularity traffic data are employed to calculate the best-fit carried traffic and then analyze its wireless channel utilization. We applied the methods mentioned above to evaluating the wireless channel utilization of the GSM networks of Guangdong Mobile in Guangdong Province. The results revealed that the cells with the same numbers of available channels but in different cell classes have different characteristics of traffic fluctuation, and differ in wireless channel utilization, thus the approach offered in the paper is more efficient and precise.