Handover Cost Optimization in Traffic Management for Multi-homed Mobile Networks

Abstract. In a multi-homed mobile network, the traffic management problem, which is to redistribute the traffic to different available wireless access networks at different geographic areas on a journey, is important and challenging. When a wireless access network is not available in an area, the traffic carried on that wireless access network has to be switched to other wireless access network(s) available in that area, which incurs a handover process associated with certain cost. In this paper, we study the traffic management problem for multi-homed mobile networks with the objective of minimizing the overall handover cost. Two different traffic distribution modes are considered in our study: the Fractional Flow Assignment (FFA) mode which assumes the bandwidth demand from one connection is infinitely splittable and can be assigned to different wireless access networks, and the Integral Flow Assignment (IFA) mode which assumes that at any time the bandwidth demand from each connection can only be assigned to a single wireless network. We show that the general FFA problem and the IFA problem are both NP-hard and propose optimal solutions to the four special cases of the FFA problem and heuristic solutions to the general FFA problem and the IFA problem. Extensive simulations are conducted to verify the impact of the capacity-demand ratio on the performance of the proposed solutions.