Optimum baseband resource switching interval determination method in C-RAN

The cloud radio access network (C-RAN) has become a promising architecture for future wireless communication system. In general C-RAN architecture, baseband units processing resource are centralized to form the baseband resource pool, which connects to remote radio units (RRUs) with the switching unit. In accordance with the traffic variation, the necessary on-state baseband resources are allocated to the RRUs in demand through the switching operation. This feature makes the system power variation accord with the traffic variation, which can reduce the unnecessary energy cost and save operating expense for mobile network operators. In practical implementation, switching intervals exist between adjacent switching operations. Shorter switching intervals bring the power variation closer to the traffic variation. However, frequent switching also brings about more overhead. Unlike simply setting the switching into a fixed value as in the literature, this paper proposes a method for calculating the optimum switching interval for the best cost saving effect for a given traffic pattern. Moreover, a fast calculating method is proposed for easy implementation.