Reducing the energy consumption of cellular wireless access networks is not only necessary for the global environment but also makes commercial sense for telecommunication operators. Since access networks are designed to support peak time traffic, the base stations that are under-utilized during low traffic periods can be switch off because traffic profile is time varying. This paper proposes an optimized heuristic algorithm to put the base station in sleep mode i.e. decreasing the no. of active base station fraction percentage without sacrificing the required quality of service and maintaining the connectivity.