Abstract
In this paper, we first introduce the notion of a critical block of hexagonal cellular network with 2-band buffering, where the channel interference does not extend beyond two cells. For a network with a given demand vector and frequency separation constraints, we present an algorithm for finding its critical block. A novel idea of partitioning the critical block into several smaller sub-networks with homogeneous demands has been introduced which provides an elegant way of assigning frequencies to the critical block. This idea of partitioning is then extended for the frequency assignment to the rest of the network. The proposed algorithm provides an optimal assignment for eight well-known benchmark instances including the most difficult two. It is shown to be superior to the existing frequency assignment algorithms, reported so far, in terms of both bandwidth and computation time.