We propose a novel distributed load balancing algorithm (D-LBSB) for the hot cell problem in cellular mobile networks. As an underlying approach, we start with a fixed channel assignment scheme where each cell is initially allocated a set of C (local) channels, each to be assigned on demand to a user in the cell. A cell is classified as 'hot', if the degree of coldness of a cell (defined as the ratio of the number of available channels to the total number of channels for that cell) is less than or equal to some threshold value, h. Otherwise the cell is 'cold'. D-LBSB proposes to migrate unused channels from suitable cold cells to the hot ones through a distributed channel borrowing algorithm. A Markov model for an individual cell is developed, where the state is determined by the number of occupied channels in the cell. The probability of a cell being hot and the call blocking probability in a cell are derived. Detailed simulation experiments are carried out in order to evaluate our proposed methodology. The performance of D-LBSB is compared with the fixed channel assignment, simple borrowing, and three existing strategies with load balancing (namely, directed retry, CBWL and centralized LBSB). By a rigorous analysis in terms of running time and message complexity, it is shown that D-LBSB performs better than centralized LBSB in an overloaded system. Also D-LBSB performs significantly better than all the other schemes in terms of call blocking probability under moderate and heavy loads.
A distributed load balancing algorithm for deduplicated storage
