UMA + RCS

In the early days of the UMA Today blog, there was much time and energy spent on articulating how IMS for applications other than telephony is actually complementary to UMA.

IMS, of course, means a lot of things to a lot of people, but for mobile operators today (UMA’s target audience), IMS is typically viewed as a means to deliver new revenue generating services above and beyond standard voice and SMS.

In response to this, leading operators and vendors intent on IMS tried to pare down the ‘Immense Menacing Squid’ as some used to refer to it, into pre-packaged set of applications that could be quickly and easily digested by a mobile operator.

The result is RCS, or the Rich Communications Suite. Announced about 6 months ago, RCS looks to wrap up IMS-based ‘rich call’ services, ‘rich’ instant messaging and enhanced address book services together into a single client that can be used on handsets today.

The implication of *today* is that it must be able to run over today’s 3G network, which in turn implies that it will use the existing circuit services network for voice, not a new IMS/SIP based telephony (a la MMTel). It stands to reason that if RCS works with standard 3G telephony, then it should work fine with UMA.

So what does all this pre-amble lead too?

I was on the GSMA site checking out the RCS section, when I happened across the release 1 specifications. I downloaded the “Technical Realisation v1.0” document and was quite surprised to see this:

Along with this text in section 2:

Note about Generic Access Network (GAN)

Generic Access to A/Gb interface provides a secure mechanism, using the SIM credentials, to access the mobile operator core network (both packet and circuit switched) using any unlicensed spectrum technology via a generic IP network. In fact, access to mobile operator core network via GAN is fully transparent from RCS perspective, and as such it does not lead to any particular limitation or impact from service point of view.

As a consequence, from access network perspective, this [GAN] technology is fully part of the scope of RCS, whatever Release is addressed, irrespective of the release.

Hey! Someone has seen the light. There is now proof from the GSMA that UMA and IMS are complementary, not competitive, technologies, at least when it comes to new service delivery.