
US
: Unlicensed Mobile Access (UMA) technology provides access to GSM
and GPRS mobile services over unlicensed spectrum technologies, including
Bluetooth and 802.11. By deploying UMA technology, service providers
can enable subscribers to roam and handover between cellular networks
and public and private unlicensed wireless networks using dual-mode
mobile handsets. With UMA, subscribers receive a consistent user experience
for their mobile voice and data services as they transition between
networks.
In order to promote
the widespread adoption of UMA technology, a number of leading companies
within the wireless industry have jointly developed a set of open
specifications. These specifications are available through this Web
site, and may be used by vendors and carriers of wireless communications
systems and applications to develop and deploy interoperable solutions.
In addition to
developing and maintaining the initial specifications, the participating
companies are actively working with the 3GPP standards organization
to use the specifications as the basis for the development of a formal
standard.
How UMA Technology Works
Enlarge Diagram
A mobile subscriber
with a UMA-enabled, dual-mode handset moves within range of an unlicensed
wireless network to which the handset is allowed to connect.
Upon connecting, the handset contacts the UMA Network Controller (UNC)
over the broadband IP access network to be authenticated and authorized
to access GSM voice and GPRS data services via the unlicensed wireless
network.
If approved, the subscriber’s current location information stored
in the core network is updated, and from that point on all mobile
voice and data traffic is routed to the handset via the Unlicensed
Mobile Access Network (UMAN) rather than the cellular radio access
network (RAN).
ROAMING: When a UMA-enabled subscriber moves outside the range of
an unlicensed wireless network to which they are connected, the UNC
and handset facilitate roaming back to the licensed outdoor network.
This roaming process is completely transparent to the subscriber.
HANDOVER: If a subscriber is on an active GSM voice call or GPRS data
session when they come within range (or out of range) of an unlicensed
wireless network, that voice call or data session can automatically
handover between access networks with no discernable service interruption.
Handovers are completely transparent to the subscriber.