Cell Planning with Capacity Expansion in Mobile Communications: A Tabu Search Approach

Scope and Purpose: For cell planning in wireless mobile communication, it is essential to consider the location and capacity of each base station to cover traffic demands in a specified region. The location of each base station is related to the coverage area and the coverage is mainly determined by the minimum received signal power from subscribers. Also the total traffic demand in the region has to be covered by selected base stations in a certain level. We consider the cell planning to cover increased traffic demands. The problem is formulated as an integer linear programming.
A tabu search heuristic is investigated to solve the problem. Intensification procedure is employed to select proper location of each base station. The capacity is controlled in the process of diversification. Cell planning in AMPS (Advanced Mobile Phone Service) and CDMA (Code Division Multiple Access) environments are examined with the procedure presented. The effectiveness of the tabu search is illustrated by various computational results.

Abstract: A cell planning problem with capacity expansion is examined in wireless communications. The problem decides the location and capacity of each new base station to cover expanded and increased traffic demand. The objective is to minimize the cost of new base stations. The coverage by the new and existing base stations is constrained to satisfy a proper portion of traffic demands. The received signal power at the base station also has to meet the receiver sensitivity. The cell planning is formulated as an integer linear programming problem and solved by a Tabu Search algorithm.
In the tabu search intensification by add and drop move is implemented by short-term memory embodied by two tabu lists. Diversification is designed to investigate proper capacities of new base stations and to restart the tabu search from new base station locations.
Computational results show that the proposed tabu search is highly effective. 10% cost reduction is obtained by the diversification strategies. The gap from the optimal solutions is approximately 1?5 % in problems that can be handled in appropriate time limits.


Full Paper