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Wireless LANs Find Their Voice

Voice-over-IP technology operating over wireless LANs has redefined voice communications, offering greater mobility and dramatic savings.

By Bob Brewin
May 17, 2004 12:00 PM ET

Computerworld - The combination of wireless LANs and IP-based telephony has forever changed the definition of mobile phones and how they're used in the enterprise.

Today, a wireless voice-over-IP (VoIP) phone operating over a WLAN can look much like a typical cordless phone. And thanks to accelerated hardware and software development, these phones are morphing into wireless IP headsets and Star Trek-like voice-activated communicators and software phones, also known as softphones, that are just another program on a laptop or handheld computer.

This hardware and software was designed to piggyback on proliferating enterprise WLANs, including new voice-grade WLAN software, access points and switches from a growing number of manufacturers.

These developments have transformed WLAN VoIP from a bleeding-edge technology in 2001 to a technology close to maturity today, says Shawn Wilde, director of worldwide operations at Trimble Navigation Ltd., a Sunnyvale, Calif.-based manufacturer of Global Positioning System receivers. Trimble began using wireless IP phones globally last year.

As WLAN VoIP technology has matured, the number of vendors that offer mobile VoIP phones and the WLAN infrastructure designed to support them has increased. Cisco Systems Inc. last year introduced its first VoIP handset and additions to its Internetworking Operating System designed to support WLAN IP voice systems.

In early March, Alcatel in Paris and Nortel Networks Ltd. in Brampton, Ontario, entered the market. Both companies will base handsets on technology developed by industry pioneer SpectraLink Corp. in Boulder, Colo. Both will resell WLAN switches and access points from San Jose-based Airespace Inc.

Market Heats Up

Vocera's voice-activated communicators
Vocera's voice-activated communicators
Airespace is one of a handful of start-ups that, along with established companies such as Cisco, Symbol Technologies Inc. and Proxim Corp., are vying to provide the quality of service and roaming infrastructure needed to support VoIP in the enterprise WLAN environment.

Chris Kozup, an analyst at Meta Group Inc., cautions that supporting VoIP calls over a WLAN presents a far bigger challenge than providing wireless data services, especially when users roam and their calls need to be handed off from one subnetwork to another. This requires the handset or softphone to obtain a new dynamic IP address, which must happen in 100 milliseconds or less, or the call is dropped.

Some companies, such as Cisco, have developed proprietary fast-roaming protocols, but Ritch Watson, director of VoIP at Holtsville, N.Y.-based Symbol, says the first industrywide meeting to discuss roaming standards was just held in March.

Despite this challenge, early enterprise adopters of WLAN VoIP say the technology delivers bottom-line savings and increases mobility in ways they couldn't have imagined.

St. Agnes HealthCare, a 299-bed hospital in Baltimore, deployed WLAN VoIP communicators from Vocera Communications Inc. in Cupertino, Calif., in lieu of installing a new paging or nurse-call system. The hospital equipped nurses, nurse technicians and care-unit secretaries with Vocera hardware last year and realized dramatic improvements in productivity, says William Greskovich, St. Agnes' CIO and vice president of operations.

The Vocera system consists of 2-oz. voice-activated VoIP communications badges. Voice traffic is directed by the system software, which runs on an Intel-based server at St. Agnes. The badges can be clipped to a shirt pocket or collar to provide a hands-free communications system, Greskovich says.

Nurses and other employees log in via a voice-recognition system with their badges and can call other employees by saying their names. The system also tracks users based on their proximity to 120 Cisco access points in the hospital, Greskovich says. To locate one another, nurses speak a simple voice command to find "Nurse X." The system responds, "Nurse X is on the fifth floor," and another command connects the nurses.

The hospital's phone directory is loaded into Vocera's software, making a hands-free call quick and easy, Greskovich says. To call the blood bank or pharmacy, nurses say the department's name and are connected. Staffers can make outside calls by saying the number, and they are then connected through a Vocera interface to the hospital's private branch exchange (PBX), he says.

St. Agnes commissioned First Consulting Group Inc. in Long Beach, Calif., in December to assess the Vocera system's effect on workflow and nurses' satisfaction. The study found that the system saves unit secretaries 1,446 hours, nurses 1,146 hours and nurse technicians 626 hours each year.

That works out to about 1.7 full-time equivalents per unit, or a savings of $74,000 per unit each year, Greskovich says. The system cost about $200,000 for the server software and $300 per badge for each of the 350 badges.

Greskovich says the Vocera system has also reduced intercom voice pages, which can be annoying to patients and staff alike. He said he believes that the Vocera system will help St. Agnes cut more hours and improve workflow this year as staffers such as maintenance personnel and security guards are added to the system.

Always On, Anywhere
Trimble Navigation has deployed a more conventional IP system: 40 of Cisco's 7920 wireless IP phones plus 20 Cisco softphones, all of which work over the company's global Internet-based virtual private network. Wilde says Trimble initially deployed the devices to IT staffers who aren't tethered to their desks.

The IP phones provide easy global connectivity, he adds. When Wilde travels to Trimble's research and development facility in New Zealand, for example, he takes his 7920 with him. When Wilde turns on the phone in New Zealand, it connects through a WLAN to Trimble's global network with the same number he uses in Sunnyvale.

The same thing happens when Wilde uses his 7920 in the company's plant in Germany, making it easier for anyone at Trimble to track him down using his standard office phone number, rather than trying to determine which country he's in and then dialing a long international phone number.

When Wilde makes an outgoing call from New Zealand, the device places the call through the PBX in Sunnyvale. Using the 7920 overseas "has definitely chipped away at my cell phone bill," he says.

Besides giving the 7920s to the IT staff and department managers, Trimble has also deployed them to workers in shipping facilities who aren't near a desk phone. The device gives these workers the connectivity and functionality of a desk phone while allowing them to be mobile, Wilde says.

Wilde adds that he wants to deploy IP phones to office and plant staff but plans to wait until he can assess the price versus performance and capabilities of combined cellular and IP phones. Such models are expected from both Motorola Inc. and Nokia Corp. later this year.

Student Body in Motion
Dartmouth College in Hanover N.H., plans to use its WLAN infrastructure to fulfill all of its students' and staffers' voice, data and video needs, according to Brad Noblet, the college's director of technical services.

Dartmouth has already deployed a wide range of VoIP clients, including 80 Cisco 7920 phones, 1,000 Cisco softphones and 100 Vocera badges. Noblet says Dartmouth also has a contract with TeleSym Inc. in Bellevue, Wash., for 600 of its SymPhone clients.

These clients operate over 500 Cisco access points, including some installed specifically to serve maintenance staff, such as in the extensive network of steam tunnels throughout the campus.

Noblet says he decided to build Dartmouth's network infrastructure around WLANs rather than wired networks because a college campus is "one of the most mobile environments," with students in constant motion between dorms, classrooms, dining halls and the library.

Noblet has bold plans to beef up the campus WLAN infrastructure to support all 4,000 students with their own softphones integrated into laptops or handheld computers. Currently, faculty, administrators and support staffers are the primary users of the VoIP hardware, he adds.

Noblet says he plans to boost bandwidth and coverage over the next 18 months, with 1,500 access points supported by the Cisco infrastructure as well as new wireless switches and low-cost access points from Aruba Wireless Networks Inc. in San Jose. When it's complete, the campus WLAN will support the majority of voice, data and video services and be one of the first and largest converged networks of its kind in the U.S., he says.

This grand vision may take longer to achieve in traditional office-based environments, according to vendors and analysts. Bill Rossi, vice president of Cisco's wireless networking business unit, says demand for WLANs and wireless VoIP still remains low in what he calls the "carpeted office."

Kozup agrees, saying that in the near future, WLAN VoIP will follow the path blazed by data WLAN installations. Users in health care, higher education and retail will be the most likely early adopters, he says.


Read more about Mobile/Wireless in Computerworld's Mobile/Wireless Topic Center.



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