Fixed Mobile Convergence

IMS (the IP-based Multimedia Subsystem) has long been touted as the inevitable destiny of the telecom industry, a standards-based common services architecture for both wireline and wireless broadband networks enabling telcos, mobile network operators and even third-party service providers to quickly and inexpensively hatch a bevy of real-time interactive multimedia services that can run on both desktop and mobile devices. But IMS adoption has been slow in the telecom world, and there are competitors: UMA (GAN), Web 2.0/Web Services/WOA, SOA, etc. All of these can both complement and challenge IMS, and each other, depending on how they’re implemented.

 

IMS was originally a 3G mobile network technology, created by the 3rd Generation Partnership Project (3GPP), but its value was immediately recognized by wireline network providers, who were building IP-based next-gen communications networks for VoIP that, like IMS, rely on the Session Initiation Protocol (SIP). IMS also makes possible dual-mode services and Fixed-Mobile Convergence (News - Alert) (FMC), thanks to the Voice Call Continuity (VCC) standard. To be specific, in a Fixed Mobile Substitution (FMS) scenario, calls are carried as VoIP over WiFi (or a femtocell) and a broadband connection, and when the user roams outside of the local wireless network range, the VCC technology kicks in and seamlessly hands over the call to the outdoor cellular network. (In the future, when WiMAX (News - Alert) and LTE 4G networks are up and running, VCC may serve as the foundation for a way to hand off calls between 4G and legacy 3G and 2.5G networks.)

 

However, in order to maintain the familiar cellular voice experience while connected to WiFi, various other service features also have to be replicated in the IP domain to run over WiFi, such as SMS and other forms of messaging. Moreover, some mobile carriers, fearing that people talking over WiFi part of the time will reduce voice revenues, have instead adopted Unlicensed Mobile Access (UMA) technology, known with the 3GPP as GAN (Generic Access Network).

 

UMA is an economical, legacy-based transport solution, originated and championed by Kineto Wireless (News - Alert). Originally posed as a way to route GSM/UMTS voice calls over WiFi and dual-mode phones, it actually supports 3GPP connectivity from a dual-mode phone or laptop softphone over WiFi or femtocells that ultimately connect to an IP network. Since it’s just a transport “tunnel” to the core network, UMA can run over WiMAX, LTE, HSPA or what-not. But because it’s a legacy network-friendly system (its architecture resembles the typical wireless network operator’s radio access network), it does tend to confine you to your particular mobile carrier’s legacy network. Unlike IMS, UMA didn’t originally support SIP, but today both SIP and IMS can be deployed on top of UMA.

 

UMA has been associated with dual-mode handsets and WiFi, but UMA can also be made to work with femtocells, those little local 3G base stations in the home or office. Dual-mode phone technology will probably be increasingly incorporated into cellular handsets, so that mobile devices will ultimately be able to work with any carrier in any kind of WiFi/femtocell scenario (tri-mode? quad-mode?).

 

Many carriers therefore jumped on the UMA/GAN bandwagon as a “quick fix” to prove that they could do cutting-edge fixed-mobile substitution. BT (News - Alert), for example, long before it unveiled its 21CN plans, launched its Fusion service based on UMA. Later, BT began to charge headlong toward IMS, running into some interoperability and second-source problems along the way. There is therefore a mythos that UMA/GAN is a “transitional” technology, and that IMS is therefore the “end game” for all network operators and providers everywhere. For many carriers and service provider this is true. But others see IMS as the last bastion (or last gasp, depending on how you look at it) of telcos protecting their turf by relegating the next-gen services layer to a separate, telco-influenced development platform distinct from the Internet.

 

Another SIP-based environment can be used to both develop and weave together (or “mashup”) services. This comes under the rubric of “Web 2.0”, which involves SOA (Service-Oriented Architectures) and Web Services / WOA (Web-Oriented Architectures). Whereas WOA tends to focus on the user interface at the endpoints, SOA, the descendant of distributed computing and modular programming, is a system-level, distributed computing design style, and can be implemented in any decentralized technology such as CORBA, DCOM, RMI, SOAP, etc. The SOA style of development “de-silos” application functionality into reusable individual units or services which can be reused and can pass data among each other over a network as they participate in business processes. Thus, one can easily do mashups. Contrast this with IMS, which also de-silos applications only insofar as the provider can quickly develop various services using IMS standards and SIP, but exposing components of the actual core service to others would be extremely difficult. SOA doesn’t need a special protocol or demonstrate any sort of interoperability to get two applications to work together. Instead, the description of the exchange of data is standardized, not the exchange itself, so connections can be devised between applications based on differing protocols – these “connections” in SOA are the Web Services, most of which still employ XML (the eXtended Markup Language) to provide the standard description model. Recently such things as XLANG and XAML have been developed, enabling complex web transactions among and between multiple web services.

 

Of course, SOA and IMS could be integrated, either via a loose Web Services adaptation layer (already used by non-IMS networks to connect with SOA) or by a more complete integration wherein IMS would rely totally on SIP-based Web Services for services delivery.

 

A Helping Hand

 

So there is a much bigger conundrum of how to run old services on new networks and new services on old ones. From the Internet/packet side, Web 2.0 is one approach. Another approach comes from AppTrigger, the company that invented the Application Session Controller, a purpose-built amalgam of media, signaling, call control, and a set of APIs for multi-network, converged application deployments. Their technology delivers time to market advantages, reduces application deployment costs, and provides feature transparency across disparate, evolving networks.

 

Patrick FitzGerald, Sr. Vice President, Global Sales and Marketing, says, “The market has very much embraced the idea that IMS is the end goal, but, fundamentally, how do you ‘get there’, what are the different migration strategies and what are the overall ‘baby steps’ you have to take to reach an ‘IMS-like’ architecture? Everybody on the Tier-1 side is driving toward some next-generation architecture and strategy and they will borrow heavily from the IMS architecture, but the end-game won’t be 100 percent pure-play IMS from an architectural perspective. Also, fundamental challenges they are encountering include, ‘How do I make that migration happen in a cost-effective, simply, easy-to-manage way?’ We see this in very pronounced terms relative to services and revenue. Fundamentally, the problem has been that within the IMS architecture, the bulk of revenue that’s being generated today by the service providers is through voice services, and the big idea within IMS was that they could recreate those voice services and then, beyond that, they could easily build some really interesting new services. In reality, however, the question in everyone’s mind is, ‘Do we need to recreate that? Or can we leverage that asset to be able to then begin to add new cool things on top of a well-understood voice service by the service provider?’ AppTrigger has maintained a thought leadership perspective on this.”

 

“We came to the market 24 months ago and talked to the market about things and realized that it’s not about IMS, it’s really about the overall migration and transition to the NGN world,” says FitzGerald. “We’ve always advocated that it’s all about preserving your revenue and preserving the applications that currently work and that subscribers always understand, but it’s also about augmenting things not only from a network layer/architectural perspective but also augmenting things from a services perspective so you can add new value-added features on top of existing offerings.”

 

“So for us it’s more about pragmatism than competition,” says FitzGerald. “What we’ve seen in the marketplace is that more and more vendors and service providers are beginning to think along those lines. Today imagine a wireless provider out there that furnishes voicemail to 18 million subscribers. But here’s the challenge from an IMS migration standpoint: the idea is to go and duplicate that voicemail service in the IMS network and so they’re essentially purchasing another voicemail solution and will provide that over the IMS network to the subscribers. Where this breaks down is when a service provider goes to implement that brand-new IMS-ready voicemail solution, and the reality is that there is no additional ARPU driven by installing this new voicemail system. So the service provider says, ‘Wait a minute, why would I spend seven or ten million dollars and take three years to deploy a brand-new system that offers the same features and functions of my existing system?’ And there’s not that many subscribers yet on the IMS side, because the handsets aren’t there and maybe the network isn’t built out enough to be able to support that many subscribers. So people began to looking at an alternative, and you started to see this through the 3GPP group, with people asking ‘Is there a way to leverage that existing asset and extend it over to the NGN buildout?’.”

 

“Fortunately, we came to market with the Applications Session Controller, a network element that sits between the services layer and the network layer, and it’s fundamentally built to manage any-to-any application network connectivity and all of the many permutations of message flow that may be required. In turn, we continue to enhance our message and we get more and more customer wins around that idea. We’re announcing what we call the Service Extender, which is our ability to take old applications and connect them to new networks, or take new applications and connect them to existing networks where all of the existing subscribers are.”

 

The IMS architecture may certainly dominate the world’s networks in 10 years, but it will either experience some stiff competition, or else it will have been modified to take into account the infinitely flexible world of Web Services and SOA.

 

Companies mentioned in this article:

 

AppTrigger

www.apptrigger.com

 

Kinteto Wireless

www.kineto.com