Unlicensed Mobile Access (UMA) is an architecture and a set of specifications that provides convergence of cell-based mobile radio GSM/CDMA networks with IP-based fixed wireless access networks. Examples of fixed wireless networks include IEEE 802.11 a/b/g WLANs, IEEE 802.16 WMANs (WiMAX), IEEE 802.20 Ultra Wideband, IEEE 802.15.1 Bluetooth WPANs, and Near-Field Sensor Networks. UMA subscribers are provided with total location, mobility, and service transparency.
UMA specifications allow development of high performance voice, data, and multimedia services over WLANs that are located in homes, offices, hot-spots, or metropolitan areas. UMA uses dual-mode, tri-mode, or multi-mode mobile phones for communications over unlicensed spectrum technologies such as IEEE 802.11x WLANs, Bluetooth WPANs, and WiMAX.
Unlicensed Mobile Access Networks (UMANs) are parallel radio access architectures that interface with the existing terrestrial mobile public network components. UMAN allows transparent handover to and from GSM/GPRS/EDGE Radio Access Networks (GERAN) and Wireless Local/Personal Area Networks (WLANs and WPANs). A specialized UMA Network Controller (UNC) or Generic Access Network Controller (GANC) is needed. This controller has similar functionality and connectivity as the Base Station Controllers (BSCs) in core mobile networks. Since the land-based mobile core network remains unchanged, it is possible to deliver full service and operational transparency across fixed-mobile networks. Standard Access Points and broadband IP-based networks are used for communications. The high-level UMA-based network architecture is shown BELOW;
Two components make up the new UMAN network: the dual mode Mobile Stations (MS), generally in the form of mobile handsets and portable terminals, and the UMA Network Controller (UNC).UNCs are collocated with mobile core network components and their coverage depends on the area designated to support WLAN/GSM convergent services. UNCs support discovery, registration, intra-system handover to other UNCs and inter-system handover between WLANs/WPANs and the GSM/GPRS EDGE Radio Access Network (GERAN). In the illustration above, the public land-based Mobile Core Network (MCN) is represented by the Mobile Switching Center (MSC), Home/Visiting Location Registers (HLR/VLR), and the Authentication, Authorization and Accounting (AAA) server. All these components provide well-known roaming and security features in traditional cellular mobile networks. Voice services are provided through the “A” interface while data services are provided through the “Gb” interface, via the SGSN.