Dynamics of Path Losses Between a Mobile Terminal and Multiple Base Stations in a Cellular Environment

We investigate the dynamics of the path losses between a mobile terminal and a small group of base stations, when the mobile traverses an area containing zones where different base stations have the least path loss to the mobile. While moving through the area, the mobile measures signals transmitted by each base station. The measurements involve calculating a running average of the measured signal power over a fixed time period. It is presumed that based on these measurements, and typically other inputs, the wireless network supporting the mobile makes handoff decisions. Practical handoff algorithms tend to be specific to match the features of the particular wireless standard. The purpose is to always support the terminal by the base station having the least path loss to the mobile, while at the same time minimize the number of handoffs. Since these are typically conflicting requirements, a practical handoff algorithm is a trade-off between the two requirements. In this paper, we do not attempt to analyze the performance of a practical algorithm. Instead, we focus on the average number of times per unit distance traveled that a moving mobile must switch base station in order to always be served by the base station with the least path loss. This is, in fact, the basis for any good handoff algorithm, and could serve as a benchmark for comparison and evaluation of practical algorithms.