According to NEC, its IP multimedia subsystem (IMS)-based femtocell systems consist of IMS Cores, femtocell gateways and femtocell access points. Softbank Mobile completed development of a commercial system in June 2008, and has already begun trial. The company plans to have IMS-based femtocell systems prepared for full commercial use commencing in January 2009.
NEC’s IMS-based femtocell system for Softbank Mobile uses an IMS configured with an SIP server to independently control communications from femtocells. The system distributes transmission load across the entire mobile network, regardless of the traffic load, and helps prevent congestion as femtocells spread and traffic increases.
The IMS framework is also compatible with backbone networks migrating to IP-based networks, and therefore facilitates the construction of all-IP networks for broadband, fixed and mobile communications.