UMA Today Magazine: Services Delivered Page 25

other major vendors have developed fully compliant
infrastructure solutions that are also available to support
commercial UMA deployments. Additionally, a large and
growing ecosystem of enabling technology companies,
including NXP, Texas Instruments, Infineon, Netrake,
Reefpoint, Audiocodes and Nethawk, have announced
UMA solutions.

Conversely, the VCC effort was initiated within 3GPP

in June 2005. While it has made some progress, as of
the end of 2006 only the requirements stage has been
fully completed, which is the first of three stages in the
standardization process (requirements, architecture and
protocols). As it is not possible to know the precise timing
for completion of the standardization process, most
industry insiders predict completion near the end of 2007.

Once the standard is fully defined, the vendor

community can complete development and begin
interoperability testing solutions. For technologies as
complex as VCC, it typically takes a year from standards
completion for mature, compliant, interoperable
infrastructure and device solutions to become
commercially available, making VCC deployments
possible sometime in 2008.

EVoLUTIon PATH To "ALL IMS" SERVIcE
coRE

Understandably, operators are reluctant to invest

in transitional technologies, especially those seen to have
a limited lifespan. It is essential any new technology be
supportive of operator plans to evolve their networks.
For example, the solution should serve a continuing role
aligned with other RAN technology evolutions as operators

make the transition to IMS for the majority of their
services, including mobile telephony.

UMA supports all major mobile core mobile network

evolution initiatives, including the transition to IMS
telephony. When IMS-based mobile telephony is
deployed, UMA will still function as the access technology
providing seamless access to (and mobility of) services
between the macro and Wi-Fi networks. As a result,
operator investment in UMA is leveraged through all
currently defined stages of mobile network evolution.

On the other side, VCC is a transitional technology.

The purpose of VCC is to enable voice calls to transition
between two core domains (an existing circuit-based core
and an upcoming IMS-based voice core) until delivery of
real-time VoIP services is technically and economically
feasible on macro cellular networks. Once delivery of real-
time VoIP services is viable over macro networks, the need
for VCC will be eliminated. In addition, as mentioned
above, once mobile operators upgrade their mobile radio
networks to support real time VoIP, UMA is the technology
that will enable access to, and mobility of, IMS telephony
between mobile and Wi-Fi networks.

Within the mobile industry, history has shown time

and again that attempts to force two different service
"domains" together typically fail to provide sufficient
transparency to be widely adopted. One recent example
is GAIT (GSM ANSI-136 Interoperability Team). While
the GAIT effort resulted in a set of specifications enabling
the development of dual-mode GSM/TDMA phones,
most operators determined the service restrictions were
too great to be acceptable for subscribers.

When examining the key decision criteria operators use

to select a DMH approach, it quickly comes clear why
the majors are selecting UMA. When it comes to the
end-user experience, deployment cost and complexity,
solution maturity, industry support and evolution path,
UMA delivers.

SPRING 2007

UMA ToDAY