Research on periodical opening of small base-stations for energy conservation

The development of wireless traffic toward high data rates and high dynamism has brought great challenges to traditional cellular networks. Heterogeneous networks with small base-station sleeping are an effective solution to this problem, which balances service quality and network energy consumption. The scheduling of small base-stations should be based on the status information about the channel between users and small base-stations. However, once the small base-stations are turned off, they switch to the sleeping mode, thus the system is unable to obtain the aforementioned information. To solve this problem, this paper presents a periodical opening mechanism for small base-stations: the system periodically opens the small base-stations to obtain channel information between the users and the small base-stations; once the users send an access request via the macro base-stations, the system makes the correspondent decision on the basis of the channel information obtained when the small base-stations were open at the last time. The design of the opening cycle is a key factor influencing the effect of this mechanism. This paper divides the total energy consumption of the network into two parts, the energy consumption for periodical opening of small base-stations and the energy consumption for user service, and works out an optimal cycle design solution balancing the two parts and minimizing the total energy consumption.