Optimized Hybrid Resource Allocation in Wireless Cellular Networks with and without Channel Reassignment

In a cellular network, the channel assignment is a mechanism that assigns channels to mobile users in order to establish a communication between a mobile terminal and a base station. It is important to determine an optimal allocation of channels that makes efficient use of channels, which are limited resources, and minimizes call-blocking and call-dropping probabilities. In this paper, we present two efficient integer linear program (ILP) formulations that optimally allocate a channel to an incoming call from a pool of available channels such that the "hard" and "soft" constraints are satisfied. The first formulation does not allow channel reassignment of existing calls, while the second formulation allows such reassignment. Our formulations can handle hard constraints, that includes both co-site and adjacent channel constraints, in addition to the standard co-channel constraints. The simplified problem (with only co-channel constraints) can be treated as a special case of our formulation. In addition to the above hard constraints, we also consider soft constraints such as the packing condition, resonance condition and limiting rearrangements to further improve performance. Experimental results on a benchmark 49 cell environment with 70 channels are used to validate our approach.