Fixed/mobile convergence: new hopes, new models: a reality check for wireless wonders

Telecommunications Americas, April, 2005 by Peter Jarich

Last year at a major telecom vendor's analyst conference, a breakout session was held on the topic of "convergence." In an attempt to be witty, one analyst explained that she wouldn't believe "convergence is real" until vendors could identify a VP of Convergence. The executive leading the session proudly pulled out a business card reading just that.

So here we are, convergence is real ... right?

A reluctance to believe in convergence as a commercial reality is easy to understand. The drivers are real enough: end-user demand for convenience (e.g., bill bundling, unified communications) combined with a desire to leverage diverse network assets (e.g., fixed/mobil). To this end, we've seen a number of attempts in the past: Cingular's FastForward, Verizon's iobi and wireless PBX solutions from multiple vendors. These products and services still exist. But, for the most part, uptake has been slow or has failed to deliver FMC (fixed/mobile convergence) in a meaningful way.

Against this backdrop of limited success, developments such as IMS (IP multimedia subsystems) present new hope for convergence. The idea of delivering or interworking multiple technologies using an IP network layer is, after all, the essence of "convergence." It also opens the door for nearly limitless converged applications: fixed-to-mobile gaming, fixed-to-mobile video, and unified messaging which leverages common presence, location and user profiles. But, this movement needs to walk before it can run. Today, one of the early front-runners appears to be fixed/mobile service roaming.

In principal, the concept of fixed/mobile service roaming is straight-forward and compelling. Equipped with a dual-mode mobile phone (a cell phone with WiFi in it), voice and data services would hand off between the wide-area 2G/3G network and a private or public WLAN network (see chart).

The potential benefits are clear: Indoor service quality would improve, mobile operators could off-load traffic from their networks, fixed-line operators could capture the demand for mobility. To this end, we've seen some early launches and trials (consider BT's Fixed-to-Mobile Convergence Alliance). But these early rumblings do not answer a number of important questions. What's different about FMC this time around? What's changed to make FMC work now? What solutions are fighting it out in the market and which are likely to succeed?

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From a market perspective, the changes are clear. Today, public high-speed data networks are nearly ubiquitous in major markets around the world. Between cable, DSL and 2.5/3G wireless, most people can get access to high-speed data around the clock. Likewise, WLAN networks are popping up everywhere, with WiFi unit sales topping an estimated 36 million last year. If you don't have a WLAN network at home and at work, you will soon.

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Separately, mobile replacement of fixed-line services continues to gain steam. Users increasingly are giving up their landlines in favor of mobiles; mobile operators want to drive the trend, fixed-line operators want to get those minutes back. Luckily, MVNOs support them in their efforts. As companies such as Virgin Mobile have validated the model, fixed-line and mobile operators alike have seen the value that MVNOs present as a way to offer a complete bundle of services, including mobility, while recapturing lost minutes to either mobile services or to VoIP services like Vonage.

In the network, things are also fairly clear. Motorola jumped into the market early, announcing work on an enterprise-based solution with Proxim and Avaya in January 2003. However, outside the enterprise, solutions fall into two categories based on where they're deployed: in an operator's packet core or RAN (radio access network).

The UMA (unlicensed mobile access) specifications, for example, deliver a RAN-based solution. Driven by technology from Kineto Wireless--though backed by Alcatel, Ericsson, Motorola, Nokia, Nortel and Siemens--the UMA spells out a network device known as the UMA network controller. It acts as a base station controller in an operator's network to enable the delivery of standard GSM/GPRS services over an IP access network to a WLAN access point.

In the core, vendors such as Bridgeport and Longboard offer solutions which essentially connect into operator softswitches or media gateways--and through them out to WLAN networks. Bridgeport supports connectivity into today's SS7 networks to tap into user identity information. Of course, as IMS comes online, each solution essentially can evolve into an IMS application server. Like the UMA, IMS is supported by most major telecom vendors, effectively adding vendors such as Lucent, NEC, Huawei and ZTE into the mix.

What's less clear is the question of which technology is the right choice for fixed/mobile roaming. Ultimately--though it may not be satisfying--the answer is likely to be, "it depends." The UMA and packet core FMC solutions deliver similar services. Both are based on industry standards--the UMA and IMS are each a part of the 3GPP specifications.