data services in the exact locations they spend most of
their time, at home and the office. For mobile operators,
UMA enables increased revenues through the acceleration
or control of fixed-to-mobile substitution (FMS) while at
the same time addressing the growing threat from new
VoIP service providers.
within the mobile community has
been the implementation and market
introduction of UMTS radio access
networks. Typically, operators launch
UMTS networks as a complement to an
existing GSM network. Additionally,
there are also stand-alone UMTS
operators (e.g., Hutchison 3G).
drivers include the ability to deliver
higher-speed mobile data services, as
well as increasing the voice capacity of
macro-radio networks.
UMA SUPPoRTS UMTS As UMA
was standardized in 3GPP, many operators
are curious to know how UMA will work
in concert with a UMTS network. One key
aspect to consider is mobility between
UMA/Wi-Fi and UMTS coverage areas.
From an overall network perspective,
seamless handover between UMA and
UMTS networks is supported in the
UMA standard today. From the GSM
core network's perspective, the UNC is
perceived as an additional BSC. Thus,
when a call currently handled by the
UNC is handed over to the UMTS RNC,
the process is the same as for calls being
handed over from a GSM BSC to the RNC.
UMA coMPLEMEnTS coVERAGE As
UMA enables the delivery of high-performance,
low-cost mobile services within homes and offices,
it provides a very effective complement to UMTS
network rollouts. As it leverages broadband access,
UMA (like UMTS) is capable of supporting high-
performance 3G services. In addition, as it leverages
existing in-building Wi-Fi networks, UMA enables
operators to address coverage and range issues of
their UMTS network rollouts.