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VoWi-Fi calls to users

Early adopters deploy voice over wireless to gain mobility and cost savings.

By Susan Breidenbach, Network World
May 03, 2004 12:00 AM ET

Network World - Organizations venturing into pre-standard VoWi-Fi waters are being driven by a critical need for real-time voice and data services. The retail, logistics/warehousing, manufacturing and education sectors are among the early adopters, but healthcare is leading the charge.

Rice Memorial Hospital was early onto the wireless voice bandwagon, installing a proprietary analog radio frequency system from SpectraLink in 1995 to augment cellular coverage throughout the facility. By late 2002 some of the SpectraLink gear had been discontinued, and replacing broken items was becoming a problem.

The Willmar, Minn., hospital wanted to move to an IP network that would support voice. "But we were also looking to improve our cellular coverage in the building, and MobileAccess had a converged platform that could do both," says Jon Barber, the hospital's telecom manager.

MobileAccess uses a hybrid fiber/coaxial backbone to distribute voice and data services to mobile users. Signals from the cellular WAN and the Wi-Fi LAN are carried on this backbone to broadband antennas that can radiate multiple kinds of services simultaneously. Fewer access points are required because each can have four antennas.

"You can put in a single infrastructure, and then add different signal types later," Barber says. "And all the [access points] are put in the wiring closet, so they are easier to get to."

Rice was the first fully integrated system MobileAccess installed, so "it was a painful process," recalls Barber. Voice requires a much stronger signal than data on a wireless LAN, because the packets have to be transmitted right the first time, and in a fixed order. After a year and a half, users are still discovering problem spots that must be filled in by adding an access point or an antenna.

The hospital is now in the midst of integrating a new nurse call system with the SpectraLink Wi-Fi handsets, and Barber is looking forward to SpectraLink's forthcoming pure- IP upgrade that eliminates the gateway between the handsets and the PBX.

"That will get rid of equipment in the switch room, and free up a lot of digital ports on my PBX," Barber says.

While Rice was evaluating MobileAccess, Condell Medical Center was looking to replace an aging wireless voice network based on proprietary Avaya access points.

Condell took a more typical route, beefing up its existing Cisco wireless data LAN to support voice. The Libertyville, Ill., medical center implemented a virtual LAN (VLAN) to give voice traffic priority, and added 10 to 15 access points - a $10,000 upgrade. The big cost was handsets, and Condell spent $250,000 replacing obsolete SpectraLink handsets with Wi-Fi models.

"We started deploying the phones last year, and it was like opening the floodgate," says Sue Mesmer, communications supervisor for the hospital. Every employee who spends time scurrying around the hospital saw the benefits immediately, and the 170 phones that were originally planned quickly expanded to 280.

The VoWi-Fi handsets are making people and processes more efficient, and the hospital is finding more uses for them. These include "code blue" broadcasts when there is an emergency, as well as integration with the nurse call system and a new patient-tracking application. The handsets have all the features of a desktop phone, and usage can be restricted according to job category. For example, the nurses can make outside calls, but the housekeeping staff can't.

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