An energy-aware data offloading scheme in cloud radio access networks

Mobile data offloading has become an important issue for mobile cellular network in recent years. Existing energy-aware data offloading scheme for mobile cellular network makes the offloading decision only according to the current local information of the user equipment (UE) and thus the UE cannot switch to a more efficient way to offload even other UEs have released their transmission resources later on. Hence, in this paper, a centralized offloading scheme based on cloud radio access networks (C-RAN) is proposed so as to make the offloading more efficient. The C-RAN based centralized offloading scheme considers all the situation of UEs of a baseband unit (BBU) at the same time and thus the BBU can do a better offloading decision for those UEs. At the beginning, each UE, who needs offloading, sends an offloading request to the BBU. When there is any UE released the transmission resource, the corresponding BBU will try to fulfill the pending offloading requests of the UEs. The corresponding BBU considers the pending UEs´ transmission rate and energy consumption of the cellular network as well as the Wi-Fi network, and then makes offloading decisions for those UEs so as to save more energy and achieve higher throughput at the macroscopic level. Extensive simulations have been conducted to illustrate that the proposed energy-aware data offloading scheme can reduce the energy consumption and turnaround time, and enhance the transmission throughput.