Abstract: Cloud radio access network (C-RAN) based on software defined radio (SDR) and virtual machine (VM) migration is a flexible architecture in the fifth generation of mobile communications system (5G). Based on the system model, we propose an optimization algorithm to choose the best base band unit (BBU) working load instead of configuring it as a constant value according to experience. The switching quality is also introduced to control the extra resource cost caused by the switching process. Simulation results show that the proposed algorithm can calculate the optimized working range for each BBU and keep the BBUs working in optimized range with low switching costs.

Key words: cloud radio access network, software defined radio, load balance, optimization algorithm