In the old days (1990s) of "unified messaging" a big, overarching program had to be written to gather email, voicemail and faxes into a single inbox and enable a response. It was assumed that the user was tied to the desktop. Indeed, at the time, that was touted as a �feature� (e.g., "Day traders! You don�t have to walk to-and-from a fax machine anymore!"). Today, the concept of FMC (Fixed-Mobile Convergence) has brought mobility to UC, via the 3GPP�s VCC (Voice Call Continuity) specifications describing how a voice call can be maintained as a user�s mobile phone (usually conceived of now as a dual-mode device) moves between circuit-switched and packet-switched radio domains. This occurred first in the form of UMA (Unlicensed Mobile Access) for GSM/WiFi (News - Alert) roaming, and now the larger, more general IMS (IP-based Multimedia Subsystem) architecture, which itself allows for more services to be added to those accessible by UC systems, opens up the possibility of triple-or-more-mode phones that could switch among various kinds of networks in an ad hoc manner.

In European countries, there was some initial interest in using DECT (News - Alert) (Digital European Cordless Telephone) and Bluetooth instead of WiFi for the "office" connection. For example, BT�s rebranded Cellnet (BT Cellnet) launched a dual mode DECT/GSM commercial service called OnePhone in May 1999. An Ericsson (News - Alert) dual-mode phone (Ericsson TH688 handset) operated outdoors on the BT Cellnet GSM network as a conventional digital cellular telephone. Within the office or home, however, the phone ran in DECT-mode with a standard domestic DECT GAP base station that�s made by Siemens; a separate DECT handset (from Siemens, who first popularized DECT immensely) was also available as part of the package. The Ericsson phone could answer two numbers: one mobile and one fixed. However, under BT's (News - Alert) Flexinumber scheme, subscribers were given one number-prefixed 070 that automatically redirects them to whichever mode the phone is in at the time of the call

Another way to add FMC to UC is to place wireless femtocells (formerly called Access Point (News - Alert) Base Stations) that use an Ethernet or broadband connection to link to the Internet or an intranet. Femtocells can provide voice and data services just as a conventional large cellular base station, but on a small scale with the ease of an WiFi access point deployment, so they can fit in a SOHO. There are CDMA-2000 and WiMAX (News - Alert) solutions being developed in this area. Within corporate offices, WiFi appears to be becoming the favored FMC phone system used "internally".

UC users could do with a slick form of mobility, since mobile phone usage in the office has reached preposterous proportions. According to Nokia (News - Alert), 50 percent of employees use a mobile phone for work. Other reports reveal that 28 percent use mobile phones as their primary phone and more than 40 percent of a business mobile phone user�s time is spent away from the desk, with nearly half of that time still on company premises. Moreover, 25 percent of mobile phone users use their mobile phones while seated at their desk.

This had led companies such as XO Communications (www.xo.com) and Sotto Wireless (www.sotowireless.com) to jointly develop Unwired Office, a service that gives employees one-number access for integrated wireless voice, email, calendar and contacts, and unlimited domestic long distance and in-building cellular usage.

At NextPoint (News - Alert) (www.nextpoint.com), the new combination of NextTone and Reef Point Systems, Mark Neider, Senior Director, says, "What we�re seeing is convergence at the edge of the network. To me, that�s very telling. Operators want to converge different functional elements together. It helps them from a cost, delivery and support perspective, but it also gives them some competitive leverage on the access side � being able to interwork with many different types of end devices in many different ways. So, to me, IMS is a component of it, but FMC is more of a telling term for what�s happening, since that�s exactly what�s happening in the networks today � convergence. IMS is just one of those protocols or architectures that are being implemented."

"Despite an overall movement toward IMS, there are still quite a few adopters of the UMA concept. The ones that I�ve noticed are France Telecom (News - Alert) and T-Mobile here in the U.S. UMA isn�t the only game in town, but it�s got some good subscriber traction. In fact, we�ve we know of some customers who signed up for T-Mobile (News - Alert) service using UMA and they�re pleased with the voice quality, the connectivity. Very positive feedback. So I think UMA is here to stay. But again, it is only one of many architectures or technologies that will be placed on the network edge which leads back to the idea of convergence."

Aaron Sipper (News - Alert), Director of Product Marketing at NextPoint, says, "UMA is just one flavor of FMC and the other item applicable to this topic would dual mode phones and deploying WiFi against the mobile network."

"From my perspective," continues Sipper, "IMS is appealing to operators from the perspective of the reusability of the core and recapturing it for different purposes. So you can have multiple applications leveraging the same common infrastructure as opposed to building out siloed networks. So, in a nutshell, IMS enables the operator to potentially reduce the cost of owning and operating a flexible network that can be shaped and formed to address new and emerging applications. FMC opens up and exploits new territory for the operators via a mobile strategy in terms of unified communications, because UC has been a fixed-line type of service, if you think about it. A sort of "fixed- VoIP" to a large degree. Voice and data have gone pretty much anywhere, but still, I see UC as having been more �fixed� until recently. Now, FMC brings in a mobile context, which is the �right� context for things such as unified communications."

"In terms of integration and interworking, even though the core is IMS, you would automatically assume that what�s IMS is also IETF in a way," says Sipper, "because everything that operators deploy in the core that�s IMS-compliant is also IETFcompliant. All operators have a vested interest in providing hosted UC services as well as integrating with IP PBX systems in the enterprises that already have UC capabilities. So I could see an enterprise strategy where a standardized, hardened core such as IMS with IETF extensions works in conjunction with IP PBXs and SIP on the enterprise side to offer extensions to the mobile handsets to make them part of the IT administrative domain. On the residential side, however, everything is typically completely hosted by the network operator for the end user for a SOHO application, or a personal service."

"This is a great topic," says Sipper, "because the mobile operators traditionally do not have a leg into the enterprise space. They don�t have really good strategies. The big operators are in there, obviously, and they�re offering services and capabilities, but now you have things such as UMA that has paired itself very well with RIM�s Blackberry. A UMA-type approach or any FMC-type approach provides the mobile operator with the tools to go into an enterprise and capture its business through UC. Whether an operator deploys IMS or not really depends on the operator and where we are in terms of a timeline. I don�t think IMS is all that ready, but it does have a lot of promise."

"So, in terms of FMC and unified communications, I think it�s a great strategy for penetrating the enterprise space," concludes Sipper.

An Enterprise Phenomenon
Tony Rybczynski (News - Alert) is Director of Strategic Enterprise Technologies at Nortel. He says, "However you define UC, we�re are talking about the enterprise end user. I don�t think I�ve seen much of UC applied for the individual consumer. IMS is certainly, in general terms, is one of the giant technology areas that certainly covers both environments. As IMS relates to UC and the enterprise market, some common technologies come into play. Certainly SIP is extremely important in both. But as we move into the enterprise and SMB area and understand what the real implications of UC are, we believe that the transformation dimensions come from taking UC and embedding it into various business applications and processes. In both environments, we�re seeing SIP as being the common �language� between devices but in terms of being able to do things relative to any sort of application environment, we�re seeing Web Services and SOA [Service Oriented Architecture] coming into play. So from a technology perspective we�re seeing a certain parallelism. IMS and UC are thus complementary. From a technology perspective there�s a lot of commonality."

"Additionally, a big component of any UC solution is certainly mobility," says Rybczynski, "and mobility by definition extends between the enterprise and carrier environments. Nortel (News - Alert) is well-positioned as being very significant in the enterprise, in carriers and in mobility across both domains. In Europe, Korea and elsewhere mobility is even more advanced, at least in terms of the true broadband experience which people are seeking out. So there�s a natural linkage to mobility."

Eric Bezille, Nortel�s IMS Marketing Leader, says, "You can click on a name in your desktop and establish a call right away. Everyone can benefit from UC functionality. You can also extend this into the mobile domain by having call management technology. IMS can extend that service and have it continue to your domain. You can start a call from the mobile side and when you enter a corporate WiFi region the call can be handed over to the local system. Another scenario is to start the call on your mobile, walk into your office and sit at your desk, then click on a button on your desktop, and the call is dropped from your mobile and transferred straight away to your laptop or desktop. All of these things can be done under the auspices of things such as IMS and UMA. These technologies are all complementary to UC."

UMA is Still a Contender
Kineto Wireless (News - Alert) (www.kineto.com) has long been the master of implementing UMA technologies. They�ve been the key innovator behind the 3GPP UMA standard as well as the leading supplier of UMA-compliant core network solutions to operators worldwide and to UMA-compliant client software solutions to mobile device manufacturers.

Steve Shaw (News - Alert), Associate VP of Marketing at Kineto Wireless, says, "UMA is about making your mobile phone work better and cost less when you�re indoors and can communicate over WiFi. To the extent that applications would then run better and perhaps cost less because UMA has delivered the service indoors, I think UC applications and services absolutely benefit from that. If you�re in the business of putting UC into your enterprise, you�re going to want your users to be able to use that anywhere, whether they�re on their mobile phones, their deskphones or their laptops, and whether they�re inside the office or outside it. UMA makes applications on the mobile work better � faster performance, higher throughput � when you�re indoors, and it costs less, because it�s running over the IP network and therefore the mobile operator charges you less for using the services. So UMA perfectly complements UC."

"UMA is simply an access technology," says Shaw, "It�s transport. To the extent that transport has any impact on the applications that it�s carrying, we�re simply making the application run better, but there�s no other impact. Transport and applications rarely �collide�, and in the case of UMA and UC, they don�t collide at all. UC is just another application or suite of applications carried by UMA."

"As the FMC market matures, UMA is evolving to universal mobile access with the introduction of new UMA-based services beyond dualmode handsets," says Shaw. "Mobile operators today are aggressively seeking new ways to leverage UMA-based technologies to launch new services including femtocells, WiMAX, terminal adaptors, and softmobiles. All of this, of course, increases the places UC can go."

An Alphabet Soup of Happiness
IMS, UMA, FMC, VCC � These acronyms - okay, they�re really "initialisms" since they consist of the initial letters of a series of words, pronounced in sequence � expand upon the services encompassed by unified communications (in the case of IMS) and (in the case of FMC, UMA and VCC), imbues UC with the ability to roam about anywhere at anytime. Although these technologies have been cast in SMB and enterprise roles, they�ll ultimately take UC even into the home, as the dividing line between our business and private lives becomes blurred.

Richard "Zippy" Grigonis is Executive Editor of TMC's IP Communications Group.

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