FMC: IMS and UMA (15/05/07)

One of the topics that came up during a discussion with a client is how would IMS replace UMA. My opinion is that UMA is something for present while IMS would be something for future. Doing some digging up afterwards turned up some interesting results.



An article in TMCNet confirmed my opinion. The following is a snippet of discussion with Steve Shaw, marketing director of Kineto wireless, it can be seen that UMA:

Shaw explained that carriers first started building IMS in order to standardize the process for wirelessly delivering the types of data services that IP enables—including push-to-talk, videoconferencing, and mapping.

As development of IMS got underway, Shaw told TMCnet, carriers realized that it could have applications for traditional voice services as well, and the specifications grew to become a potential enabler of FMS.

Today, IMS is generally viewed as the way in which all networks—both fixed and mobile—will evolve to become completely IP-based.

The problem is that, although IMS has lots of promise for many applications (including FMS), it is not yet fully developed and the number of specifications involved is still growing.

“IMS isn’t a specification, it’s a journey,” Shaw said

He added that IMS eventually will solidify and deliver on its promise, but that probably will take another decade or more.

Although beginning the transition to IMS-based systems now may theoretically be a good long-term investment, for many carriers the cost simply cannot yet be justified. That leaves them looking for a non-IMS way to cost-effectively deliver FMS now.

UMA, For Now

As a fully-developed specification capable of delivering low-cost FMS service today, UMA is the no-brainer choice for most operators, Shaw told TMCnet.

“UMA is unbelievably inexpensive and low-impact. There is really nothing else that has the same approach,” he said.

UMA isn’t perfect, of course, and cannot provide all the functionality that IMS promises to someday deliver.

Shaw noted that some companies who build IMS-based applications have positioned UMA as being a temporary solution, and one that operators will regret investing in because new specifications will come along and render UMA obsolete.

That could end up being true, but operators still need a way to cost-effectively deliver FMS now, and for the time being UMA is the only specification available to do that.

Shaw added that 3GPP has started work on a second-generation version of UMA—dubbed eUMA—that will add more functionality including the ability to natively connect into high-speed data portions of 3G networks.

There are couple of white papers from Kineto wireless which are an interesting reading. The first is "How UMA Enables Broadband IMS" and the other is "The Complementary Roles of UMA and IMS in Fixed-Mobile
Convergence"

I found another old article from last year talking about the same thing.