Adaptation of Terminal to Base Station Assignment to Terminal Activities and Rain Event in Broadband Fixed Wireless Access Systems

Abstract:
In point-multipoint systems the signal to interference plus noise ratio highly depends on the assignment of terminal stations (TS) to base stations (BS). The Broadband Fixed Wireless Access (BFWA) systems operate at high carrier frequencies, i.e. microwave domain. In this frequency range wave propagation is highly influenced by precipitation, especially rain. Applying site diversity can mitigate rain attenuation effects, when downlink signal level decreases below a threshold, terminal station can be assigned to an other base station, though in point-multipoint systems this base station re-assignment can raise uplink interferences at other terminals. Present contribution provides a special diversity method which adopts genetic algorithm to dynamically optimize TS-BS assignments in BFWA service area from interference point of view. Efficiency of applying various objective functions are compared considering different aspects.