Patent ID: 9713009
Date: 2017-07-18
CPC Classifications: H04W

Claim:
1. A macro base station in a communications system which includes the macro base station, a plurality of UEs (user equipment), a plurality of small cells, and a network through which the macro base station, the UEs, and the small cells communicate with each other, the plurality of small cells within a macro coverage area of the macro base station, the macro base station comprising: a processor, a memory, and a small cell on/off module which is operable, for each small cell of the plurality of small cells, to: determine an interference metric for the small cell; if the determined interference metric meets a preset condition for the small cell, then determine a loss in signal strength to the UEs associated with the small cell caused by switching off the small cell; and judge whether to switch off the small cell based on at least one of the determined interference metric or the determined loss in signal strength, wherein for each UE i, the small cell on/off module is operable to determine a small cell j of the plurality of small cells that has a highest downlink reference signal received power (DL RSRP) value to the UE i, and the UE i would normally connect to the small cell j given by M(i)=argmaxi S(UEi, SCj), where UEi stands for UE i and SCj stands for small cell j, wherein for each small cell j, the small cell on/off module is operable to determine a set of UEs i, which would normally connect to the small cell j based on highest DL RSRP value, the set of UEs being denoted by N(j)={i|j=M(i)}, wherein for each small cell j, the small cell on/off module is operable to check if the set of UEs N(j) is empty or not and, if empty, then to switch off the small cell j, wherein if the set of UEs N(j) is not empty, then the small cell on/off module is operable to define the interference metric for small cell j as I(j)=Σi≠N(i) S(UEi, SCj), which sums up the DL RSRP values to all UEs which are not in N(j), and wherein the small cell on/off module is operable to check if the interference metric I(j) for the small cell j is above a preset first threshold and, if not, then to judge that the small cell j is not to be switched off.