IMS is Down, but not Out

By Richard "Zippy"
Technology is a funny thing. You’re a prehistoric fellow who discovers fire, and somebody else invents the barbecue. You invent bread, and somebody else invents sliced bread. Similarly, IMS was conceived as the be-all and end-all of service architectures, a common platform for both wireline and wireless network operators so that proprietary, silo-ed, back-end network architectures could be replaced with a uniform, IP-based system making it quick, easy and above all inexpensive to deploy exciting new applications.

But now it’s looking that IMS is going to have to evolve in the face of a fast-changing telecom world.

The critical voices are many, and what they say can make an IMS aficionado cringe:

• IMS, a creation of the big carriers, is too voice-oriented.

• IMS is too complicated.

• IMS costs too much to implement, especially in today’s economically-floundering times.

• IMS is simply the IN (Intelligent Network) reborn.

• IMS products tend to be “old wine in new bottles” – slightly re-jiggered equipment with an IMS label on them.

• SOA, SaaS (News - Alert), Web 2.0 and Web Services can do an end-run around anything that IMS can do.

• ILECs and Tier-One carriers always get into trouble when they try to push “top-down” designed and decreed standards, such as ATM, and IMS is no exception.

• UMA, supposedly a quick fix to achieve IMS-like Fixed-Mobile Convergence (FMC) capabilities, is becoming quite popular.

Even some of IMS’ supporters get things wrong. IMS in and of itself doesn’t guarantee Quality of Service (QoS), let alone end-to-end Quality of Experience (QoE). (Indeed, QoS is becoming something of a red herring, as the average quality of many VoIP lines – such as the one I have from Cablevision – is actually better than some circuit switched lines.) IMS does make uniform billing and OSS possible, though any carrier will tell you that you can’t totally de-silo every application, and some applications must have an intimate integration with BSS and OSS and can’t simply be totally modularized and insulated from other workings of the back office.

Still, even die-hard critics of IMS give it a back-handed complement now and then. My friend Chris Gatch at Cbeyond (www.cbeyond.com) has written, “The good news is that just like ATM led to advances like MPLS for IP, so will IMS concepts help mainstream VoIP. The Home Subscriber Server or HSS, analogous to the Home Location Register or HLR in mobile, is a good idea, and I have no doubt the concept will survive in a standalone form in emerging mobile VoIP networks. Perhaps some of the optimizations around hierarchical identity will survive too… mobile networks optimized for data and QoS are not far away.”

Everybody seems to miss the fact that IMS is still slowly percolating through the world’s networks, transforming bits and pieces of them as it goes. It remains and a recognized world class recognized to build off, even if obliquely, such as the “Rich Communications Suite” (RCS) mentioned recently by Dean Bubley (News - Alert), and promulgated by carriers, a “lowest-common-denominator IMS mobile client, that incorporates a presence-enhanced address book with some IM capabilities and bits of file/image/video-sharing”.

IMS is not absolutely necessary to deploy all applications – heaven knows that the cable companies have demonstrated you don’t need it to offer triple and quad-play service bundles – and yet it appears that IMS allows an application to benefit from both wireline and wireless markets. Given that IMS came out of the 3G world and that the major trend these days is to bring more functionality and convenience to the mobile world, IMS remains the “rock” off of which new ideas should be cantilevered. But eventually, of course, under the influence and cross-pollination by web-based and mobile technologies, the IMS rock will probably be chiseled into something that looks a bit different than what we have today.

Richard Grigonis is Executive Editor of TMC’s (News - Alert) IP Communications Group.

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