ملخص: 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. In this paper, we do not attempt to analyze the performance of a practical handoff algorithm. Instead, we focus on the average number of times per meter traveled that a moving mobile must switch base stations in order to be always served by the base station with the least path loss. The switching rate is a function of the mobiles location with respect to the base stations and the velocity of the mobile. For low velocities, the multipath fading is not averaged out completely and, therefore, affects the measured results, while at high velocities the multipath fading is averaged out, but the resolution of the measurement is compromised, and any possible handoff will be delayed (in terms of location). In the sequel, we assume that the multipath fading has been averaged out, so we have a simple propagation channel model composed of two parts: a distance attenuation and a shadow loss. We also assume the validity of certain correlation and autocorrelation models describing statistical relationships between the path losses of the links involved.

لغة: إنجليزية