FMC, UC, UMA: Making sense of the acronyms
Before I delve too deeply into this topic, let's clarify the terminology lest we become hopelessly entangled in a confusing morass of acronyms.
FMC: Broadly defined, FMC integrates wired and wireless telecommunications. There are many examples of FMC products. The simplest and most widely deployed example is the "mobile extension" PBX feature. Mobile extension treats the mobile device as an enterprise phone by intercepting incoming calls and routing them to the mobile device.
Dual-mode FMC: This form of fixed mobile convergence relies upon dual-mode phones (i.e., mobile cellular and Wi-Fi) and phone-based clients to enable users to seamlessly roam between a wireless LAN (WLAN) and a cellular network. Examples include Agito's RoamAnywhere, and DiVitas' Mobile Unified Communication.
Mobile unified communications (UC): Mobile UC integrates mobile phones with UC solutions by installing a client on the phone that communicates with a UC server. The mobile client provides a softphone-like UC interface to the user. Examples include Siemens' Openscape Mobility, Cisco's Unified Mobile Communicator, and Avaya's One-X Mobile. Many UC vendors broadly use this term to include FMC and dual-mode FMC solutions.
Unlicensed mobile access (UMA): UMA permits dual-mode Wi-Fi cellular phones to roam
between WLANs and mobile cellular networks. However, unlike enterprise dual-mode FMC solutions, UMA
works only with GSM
networks (e.g., AT&T and T-Mobile) and not with CDMA2000 networks (e.g.,
Sprint Nextel or Verizon). Also, the mobile operator, not the enterprise, controls the
inter-network call handoff.
The benefits of dual-mode FMC
Dual-mode fixed mobile convergence vendors promote many benefits. Oftentimes, however, these benefits are difficult to realize or are achieved without using dual-mode phones:
Save money: Dual-mode FMC solutions offer the potential to save the enterprise money by reducing mobile cellular minutes of use when voice calls roam to the Wi-Fi network. But there are several reasons why the savings may not be as great as expected.
- The enterprise may need to broaden WLAN coverage. A voice-ready WLAN must provide broad coverage to areas such as stairwells, restrooms and closets, whereas a data-only WLAN does not necessarily need coverage in these areas. Therefore, any savings may be offset by increased WLAN equipment costs.
- The enterprise may need to modify WLAN design. Voice applications are very sensitive to packet loss, jitter and latency. A voice-ready WLAN must be designed to minimize these parameters for the expected call volume, otherwise call quality (e.g., mean opinion score) will suffer. Conversely, data-only applications are much less sensitive to these parameters.
- The enterprise may need to invest in additional training and tools. A help desk that supports voice must be prepared to quickly diagnose and solve voice quality problems. This may require investment in voice-specific tools such as the AirMagnet VoFi Analyzer (AirMagnet is now owned by Fluke).
Improve voice coverage: In areas where cellular coverage is poor, a dual-mode FMC solution can improve voice coverage. However:
- Improved coverage may require equipment investment. As described above, the enterprise may need to invest in additional infrastructure and tools.
- Cost-effective alternatives exist. Oftentimes, wireless operators will heavily discount the installation of a distributed antenna system in order to win enterprise business.
- New technology may help. Femtocells are still bleeding-edge technology, but someday they may provide a cost-effective alternative to voice over WLAN.
Reduce roaming charges: Many dual-mode FMC solutions can intelligently route international mobile calls through trunks connected to the premises-based PBX, saving per-minute international roaming costs. But many FMC solutions, such as Ascendent Systems' Voice Mobility Suite, also provide this capability without requiring the use of Wi-Fi phones.
Integrated enterprise telephony: Mobile users often endure inconveniences such as dependence on two phones (i.e., desktop and mobile), two phone numbers, and two voice mailboxes. Dual-mode FMC solutions can solve this problem by integrating the mobile phone into the enterprise telephony system. They can also extend PBX-like features (e.g., call hold/forwarding/transfer) to a mobile phone, but many FMC solutions provide this feature without requiring the use of Wi-Fi phones.
Dual-mode fixed mobile convergence has not been widely embraced by the enterprise because many of the benefits are either difficult to realize or can be achieved using alternative FMC solutions. Dual-mode FMC is therefore likely to remain a niche, and mobile phones that operate over cellular networks (circuit-switched and packet-switched) will be the dominant form of voice communication.
About the author: Paul DeBeasi is a senior analyst at the Burton Group and has more than 25 years of experience in the networking industry. Before joining the Burton Group, Paul founded ClearChoice Advisors, a wireless consulting firm, and was the VP of product marketing at Legra Systems, a wireless-switch innovator. Prior to Legra, he was the VP of product marketing at startups IPHighway and ONEX Communications and was also the frame relay product line manager for Cascade Communications. Paul began his career developing networking systems as a senior engineer at Bell Laboratories, Prime Computer and Chipcom Corp. He holds a BS in systems engineering from Boston University and a master of engineering degree in electrical engineering from Cornell University. Paul is a well-known conference speaker and has spoken at many events, among them Interop, Next Generation Networks, Wi-Fi Planet and Internet Telephony.
This was first published in August 2009