Wi-Fi/cellular convergence presents challenges

The convergence of desktop and mobile phones into single go-anywhere gadgets that work on multiple wireless networks may seem just around the corner, but  large-scale deployments are still a long way off, according to IT professionals and vendors at Interop.

The concepts seem simple enough -- a Wi-Fi/cellular device that lets you keep talking as you walk out of a building (using a Wi-Fi VoIP network) and into the parking lot (covered by cellular), or vice-versa. Complex hand-off technology between networks, varying standards in handset technologies and a reluctance by carriers to give up billable cell phone minutes to customers with their own VoIP-enabled wireless LANs could present some barriers.

What is known as Fixed/Mobile convergence (FMC), "will be a big plus for end-users, because they'll be able to just communicate," said Craig J. Mathias, a Computerworld columnist  and principal of the Fairpoint Group, a consulting firm, who led Interop's wireless conference track.

As users move in and out of Wi-Fi and cellular network zones, calls would be passed off among corporate WLANs and carrier cellular networks. "You won't really know what particular network you're using," he said. This will also radically change how enterprise communications networks are built, and the types of services enterprises buy to support them.

"You won't need a desk phone anymore," Mathias said, "or the copper running to the desk, or a pure-wireline voice carrier, or even a PBX."

This potential shakeup of the traditional business/carrier services relationship is where the high-minded concept of FMC meets reality, others said.

"We're still probably three years away before this starts to become a common service," said Alan Cohen, senior director of mobility solutions at Cisco Systems Inc. Right now, carriers are hesitant to help out in this area because there isn't much in it for them, he said.  "Moving a call out of the cellular [cloud] and onto a campus Wi-Fi VoIP network takes billable minutes away from the carrier." This will take a huge push from users to get going. A Ford, GM or an IBM will have to start demanding this kind of service on a large scale.

One user who attended Interop is ready for fixed-mobile convergence now, but sees little support for it among carriers and equipment makers.

The campus at Northwestern Memorial Hospital in Chicago is as ready as any network for fixed-mobile convergence. The hospital recently installed a converged radio antennae infrastructure from Mobile Access, according to Dan Curran,  the hospital's IT director. This technology combines cellular, 802.11, RFID and any other type of over-the-air communications the hospital may want to deploy. Cellular network providers -- Sprint and Verizon among them -- come in loud and clear through the hospital's halls, as the Mobile Access antennae amplify the cellular signals internally. The Mobile Access antenna infrastructure also feeds the hospital's Cisco WLAN access points, which are deployed centrally in wiring closets instead of spread though the campus.

To cut its cell phone bills, Curran recently started giving out Cisco 802.11 IP phones to doctors, nurses and staff. "They loved it," Curran says. "But one of the issues was that if they made a phone call in the building, as soon as they step out, it goes dead." On top of that, end users we'e not pleased with having to carry two handsets -- cellular and 802.11 -- when roaming around the campus.

"We just need that simple device," that ties a desk extension to a mobile device, and changes from 802.11 to cellular as end-users roam outside buildings.

There are no shortages of simple devices that provide dual-mode connectivity. Dual-mode devices are made by Motorola, Cisco, Samsung, LG and other makers. ABI Research estimates that shipments of these wireless handsets will exceed 300 million units by 2011.

Various products also provide the cellular/VoIP handoffs, or some degree of dual-network tie-ins. Avaya offers an extension-to-cellular technology, allowing Motorola cell phones to log into a PBX network and impersonate in-office phones. Avaya is also working with carriers such as BellSouth on a hand-off service. BlackBerry-maker RIM has the Ascendant Voice Mobility Suite, which rings desk and cell phones simultaneously. Start-up DiVitas Networks offers an appliance that ties mobile and desktop phone extensions into a single device.

For other Interop attendees interested in fixed-mobile convergence, the devil is in other details for now.

The Visiting Nurse Services (VNS) of New York, which runs an Avaya VoIP network and a Cisco WLAN, uses the extension-to-cellular option, but Avaya's nascent Wi-Fi/cellular handoff had one problem. "It's all GSM-based," said Randy Cleghorne, director of IT planning and management at the VNS. All of the cell phones used by VNS employees run on CDMA mobile technology, which is not supported in the hand-off technology. "I would really like to see that cell option come along," she said.

One IT professional at Interop said he's not interested in converging Wi-Fi and cellular voice onto a single mobile handset  since most of the 400 or so employees in his organization use voice-enabled BlackBerrys as their primary communications device.

"The coverage is good, and it solves the mobility problem," said David Feldman, vice president and systems architect for hedge fund giant Tudor Investment Corp. in Greenwich, Conn. Instead of converging the desktop and cell phone, end-users at the company are looking for the next level of mobile device convergence, Feldman said -- streaming video and data to the BlackBerry screen.

To that end, Tudor is looking into delivering live streaming Bloomberg data -- market numbers, as well as some live video content -- to the tiny BlackBerry screens of the firms top 100 or so employees -- such as high-level investment executives and traders. Feldman said he is looking to deploy software from a company called Pyxis Mobile, which makes tools that allow streaming information and multimedia on mobile devices.

This story, "Wi-Fi/cellular convergence presents challenges" was originally published by Network World.

Copyright © 2006 IDG Communications, Inc.

Bing’s AI chatbot came to work for me. I had to fire it.
Shop Tech Products at Amazon