摘要：The coexistence of LTE, WiFi and WiMax forms the heterogeneous network (HetNet) nowadays. The most common problem in HetNet is the load balance between different types of network, which would be even more difficult when the users' demand is considered. For the purpose of this paper, we proposed a load balance algorithm based on utility function (LBUF). This algorithm considers network load level and users' demand at the same time. A self-adaptive threshold is defined for dynamically controlling the load between the networks according to the number of loads in the whole network. What's more, the LBUF algorithm needs to gather the global information of the HetNet, and the software-defined network (SDN) is able to provide the data we need. So the LBUF algorithm is suggested being installed in the SDN controller. The numerical simulation results demonstrated the fast convergence of our approaches.
