Femtocell is a technology that allows users of wireless devices, such as cell phones, PDAs, laptops equipped with cellular communications capabilities, or the like, to install small base stations in the indoor environment using licensed spectrum in order to increase coverage and/or throughput. Femtocells may provide access between a wireless device and a mobile network operator (MNO) core network. For example, the femtocell may be coupled to the operator core network through the Internet. Femtocell base stations may be installed by customers of MNOs on the customer's premises. Aspects such as energy consumption and electromagnetic emission may therefore be important factors for customer acceptance of femtocell products. FIG. 1 illustrates a femtocell base station 110 operatively coupled to an operator core network 120 via an Internet connection 130. The femtocell 110 may operate as a base station for a wireless device 140. Alternatively, a macrocell 150 may operate as a base station for the wireless device 140.
Some technical standards related to Femtocell technology include 3GPP TS 25.367 V9.2.0, “Technical Specification Group Radio Access Network; Mobility Procedures for Home NodeB; Overall Description,” 3rd Generation Partnership Project, Stage 2 (Release 9), December, 2009; 3GPP TS 25.467 V9.1.0, “Technical Specification Group Radio Access Network; UTRAN architecture for 3G Home Node B (HNB),” 3rd Generation Partnership Project, Stage 2 (Release 9), December, 2009; and 3GPP TS 25.469 V9.0.0, “Technical Specification 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; UTRAN Iuh interface Home Node B Application Part (HNBAP) signalling,” 3rd Generation Partnership Project, (Release 9), December, 2009.
There are several differences between a femtocell base station and a traditional cellular base station. A femtocell base station typically connects to the core network using a broadband Internet connection such as DSL, cable or Optical Fibre. Additionally, a femtocell base station may be placed in a user's home or an office building, and typically does not belong to nor is it under direct control of a MNO. For example, an owner of a femtocell base station may want to restrict access to their femtocell since they pay the expense of maintenance and the broadband connection to their premises. As such, a closed subscriber group (CSG) is defined in 3GPP and other standard bodies (e.g., IEEE 802.16m) for a femtocell base station. In other words, a femtocell base station is typically accessible only to terminals which are members of this base station, except for emergency services.
The traditional practice of having radio equipment continually turned on can result in energy being wasted. In addition to wasting energy, always-on radio equipment can increase radio interference and radio emissions in nearby areas.
Some power-saving techniques have been proposed for non-femtocell base stations, such as macrocells. For example, Ericsson™ has introduced a Base Transceiver Station Power savings feature, wherein, during periods of low network traffic, those parts of the network that are not being used may be powered down. Alcatel-Lucent™ offers a feature called Dynamic Power Save which enables a GSM base station to monitor traffic activity on the network and switch off the amplifier when there is no information to transmit. However, these approaches are unsuitable for femtocell base stations, for example since they may require knowledge of the network traffic load and full ownership of the base stations by the MNO. Furthermore, such solutions may not fully leverage the potential capabilities of a femtocell, for example as enabled by the availability of closed subscriber groups.
Therefore there is a need for a solution that overcomes at least one of the deficiencies in the art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.