Network-assisted idle procedure in closed subscribed group cell

A femtocell that provides cellular coverage in the local areas using licensed spectrum has attracted much interest in the cellular network architecture and was expected to deploy extensively in near future. However, the femtocells hasn´t widely deployed yet because several problems are not clearly solved. First the additional energy consumption is caused by femtocells due to their continuous receptions and transmissions, different with wireless LAN access point with discontinuous processing. Secondly, the continuous transmissions of reference signals for cell coverage can cause interference between cells, which may degrade the overall network throughput. In this paper these problems are solved by a novel network-assisted idle mode procedure that allows the femtocell processing to be turned off completely or in part when the femtocell does not need to turn on, based on mobility of the registered subscribers.