(This article originally appeared in the April 2008 issue of Internet Telephony magazine.)
The term “Fixed Mobile Convergence (News - Alert)” (FMC) is clearly defined in the carrier world. It means seamless transition of calls in progress between cellular and WiFi connections on a dual-mode mobile phone. The technologies used are UMA
(Kineto’s Unlicensed Mobile Access) or the VCC (Voice Call Continuity) part of the IMS (IP Multimedia Subsystem (News - Alert)) specification. A natural side effect of carrier FMC is that the phone has a single phone number spanning both the cellular and WiFi
networks. Carrier FMC also has data session continuity to complement the voice session continuity, but the defining characteristic of carrier FMC remains seamless session continuity between the cellular network and WiFi (News - Alert) through the Internet.
One might think that Enterprise FMC would be as clearly defined, but it’s not. For years vendors without seamless session continuity solutions have used the term “Enterprise FMC” for various other capabilities instead. This means that when you hear the term “Enterprise FMC,” you need to drill down a little to find out what is actually being talked about. There are three main capabilities that have been described as Enterprise FMC:
Mobility extends the features and functionality of the enterprise PBX (News - Alert) out to mobile phones, making them behave like PBX deskphones, but over the cellular network.
Device Handoff is session continuity over multiple devices, so a single voice session might start on a cell phone and transition to a PBX phone or vice versa. These transitions are not “seamless,” since they require the user to press a button or make a menu choice.
VCC (just like in the carrier world) is session continuity on a single device (a dual-mode phone) over multiple network connections, so a single voice session can start on the cellular network and automatically transition to a WiFi connection or vice versa.
Some PBX Mobility products use dual mode phones, but still fall short of VCC. Like VCC solutions, they have a user interface that looks and works the same for cellular calls and WiFi calls, but the WiFi-cellular handoff isn’t automatic; like Device Handoff solutions, the user must transfer the call manually.
In addition to requiring dual-mode phones, VCC requires a device that embodies the call continuity control function. This is the server that anchors a call, seamlessly routing it over the WiFi connection or the cellular connection as needed. The location of this device is a defining difference between Enterprise FMC and consumer FMC. In all implementations of consumer FMC, this device is in the carrier network. In Enterprise FMC this device is on the customer premises, like the PBX.
Michael Stanford has been an entrepreneur and strategist in Voice-over-IP for over a decade. His strengths are technical depth, business analytic skills and the ability to communicate clearly. In his current consulting practice, Michael specializes in VoIP wireless networks, both WiFi and WiMAX. Internet Telephony Magazine recognized him as one of “The Top 100 Voices of IP Communications” and VoIP News (News - Alert) named him one of “The 50 Most Influential People in VoIP”.