Dynamic soft-combine zone configuration in a multicast CDMA network

Focusing on multicast transmission in a CDMA based 3G system, we address a soft-combine zone configuration problem. The problem is to find a limited number of cells supporting soft-combine such that each cell has at least one neighboring cell, which also supports soft-combine, while the sum of traffic demands of the selected cells is maximized. We show that this problem is NP-hard, introduce an integer programming formulation, and develop an algorithm generating upper and lower bounds for the soft-combine zone configuration problem, which enables the optimal zone configuration easy to solve in real-time fashion