Joint optimization of radio repeater location and linking in WLL systems with 2.3 GHz frequency band

This paper considers the problem of choosing the optimum location for WLL radio repeaters in wireless local loop (WLL) systems. According to the field measurement results, more coverage holes occur within the cell coverage areas in the WLL frequency band, i.e., 2.3 GHz, as a result of weaker diffraction effects at the higher frequency. The phenomenon is critical in urban and suburban environments. One of the solutions for overcoming the phenomenon is to use WLL radio repeaters. WLL radio repeaters should be located optimally within the cells and be linked optimally with WLL terminals by fiber optic lines. The problem is formulated as a large combinatorial optimization model that determines the radio repeater locations minimizing the total system cost and satisfying the required received radio signal strength. The propagation model proposed by JTC is incorporated in the model in order to determine the locations that satisfy the requirement. A heuristic algorithm is developed to solve the model and numerical tests are performed for the performance of algorithm.