Worst-case performance of cellular channel assignment policies

Many cellular channel assignment policies have been proposed to improve efficiency beyond that resulting from fixed channel allocation. The performance of these policies, however, has rarely been compared due to a lack of formal metrics, particularly under nonhomogeneous call distributions. In this paper, we introduce two such metrics: the worst-case number of channels required to accommodate all possible configurations of N calls in a cell cluster, and the set of cell states that can be accommodated with M channels. We first measure two extreme policies, fixed channel allocation and maximum packing, under these metrics. We then prove a new lower bound, under the first metric, on any channel assignment policy. Next, we introduce three intermediate channel assignment policies, based on commonly used ideas of channel ordering, hybrid assignment, and partitioning. Finally, these policies are used to demonstrate the tradeoff between the performance and the complexity of a channel allocation policy.