Hospitals in the US are finding voice over wireless LANs to be just what the doctor -- and more to the point, the nurses -- ordered. While VoWi-Fi technology is hardly commonplace yet, its growing acceptance in life-or-death situations is a testament to the value of convergence and mobility.

At the moment, most of the case studies are in the US, but some, such as George Eliot Hospital are emerging in the UK.

But why do it? Hospitals are places where staff are mobile, suggesting a wireless solution, but there are also sensitive electronic systems, so certain wireless technologies such as mobile phones are ruled out.

"Healthcare has high-value people in information-intensive jobs who move around constantly and play different roles at different times," says Eric Brown, a vice president at Forrester Research. "It's the perfect combination for VoWi-Fi."

VoWi-Fi also helps boost productivity by eliminating the need for nurses to waste time searching for phones to use. "Hospitals need VoWi-Fi because nurses don't sit behind desks," says Craig Mathias, principal analyst at Farpoint Group.

Here are some highlights of the US experiences of VoWi-Fi in healthcare.

Pioineers got there in 2001!
The need to improve communications and provide better access to resources drove Overlake Hospital Medical Centre of Bellevue, Washington, onto VoWi-Fi's bleeding edge three years ago.

"Our two biggest issues were roaming and security," says Kent Hargrave, chief information officer of the 337-bed hospital. Overlake settled on Airespace for its 802.11b/g WLAN infrastructure, citing superior roaming capabilities, ease of implementation and management, and scalability. "It also cost about 50 percent of the other solutions," Hargrave says.

The client devices and voice switches at Overlake are mixed. Clinicians needing hands-free communication are equipped with Vocera badges, while handsets include Cisco 7290s and the Avaya/SpectraLink 3626.

Cisco's Call Manager is deployed in one department while an Avaya Media Server serves the rest of the hospital. The Avaya product is the current favourite, integrating with Overlake's Avaya PBX and extending voice mail and call forwarding to the wireless network. But increasing wireless handset use to enter medical data via XML eventually could tip the scales in Cisco's favour, Hargrave adds.

Because Overlake deployed its WLAN before the 802.11i standard was finalised, the hospital shored up security by implementing Wi-Fi Protected Access (WPA) and configuring the access points so they don't broadcast Server Set Identifiers. Products based on 802.11i will be evaluated as they become commercially available.

Adding voice meant firmware upgrades
Children's Hospital Central California in Madera let VoWi-Fi mature a bit before jumping on board. The 255-bed pediatric hospital started putting voice on its 802.11b WLAN in mid-2003.

The network includes an Avaya PBX, SpectraLink-manufactured Avaya 3606 and 3626 handsets and Cisco 1200 access points. Wired Equivalent Privacy security is enhanced by segregating the phones on a separate virtual LAN.

A pilot project revealed bugs requiring firmware upgrades. The centralised Dynamic Host Configuration Protocol (DHCP) servers weren't on the same subnet with the phones, and requests had to go across routers in packets of at least 300 bytes. The phones wouldn't allow packets that large until SpectraLink developed a fix.

Similarly, Cisco had to tweak its access points to reduce an SNMP polling latency that went unnoticed when the WLAN was data-only. The access points were pausing the radio signal for about a second whenever they received a request from the WaveLink Mobile Manager management application.

"Still, it only took a one-month pilot to get these bugs worked out," reports Joseph Egan, Children's' network engineer. Children's is now testing a push-to-talk feature on the 3626 phones to broadcast Code Blue alerts that summon emergency teams.

VoWi-Fi cuts the device complexity
At the UC Davis Medical Center (UCDMC) in Sacramento, a wireless hospital-wide implementation began this spring.

"We've been using phones, voice mail, e-mail, individual pagers, group pagers, nurse-call pagers, overhead paging, intercom systems, radios, cell phones, fax, text messaging and clinical messaging on our EMR (electronic medical records) system," says Lisa Trask, a registered nurse and an associate director in UCDMC's patient care services division. "It's insane."

The healthcare organisation is reducing device types and communication methods to three basic sets. Desk workers have traditional phones. Mobile clinicians who have no on-call responsibilities outside the hospital get Vocera badges. And on-call administrators and clinicians get cell phones -- ultimately the multiservice handsets that can roam between cellular and Wi-Fi networks.

"Over the next several years, we plan to reduce phone lines by 40 percent and pagers by 90 percent," Trask says. "Bandwidth is our biggest consideration, and we are upgrading to 802.11g next year."

The VoWi-Fi initiative dovetails with UCDMC's implementation of an EMR system and migration to electronic order entry and clinician documentation. The hospital is working with vendors on a voice-login interface that clinicians can use to dictate directly into the EMR system from the Vocera devices.

Building in VoWi-Fi from the start
Unlike most early VoWi-Fi adopters, Indiana Heart Hospital (IHH) in Indianapolis was designed from the ground up to use IP telephony.

The hospital was opened in 2002, with a Cisco infrastructure and SpectraLink handsets. Data runs over 802.11a, and voice is on a separate 802.11b VLAN.

Bedside charting and order entry are now done via 350 wired PCs that blanket IHH. But going forward, IHH is moving to Cisco's XML-enabled handsets.

"The marriage of voice and data on a wireless appliance will be huge," asserts Kevin Hartzburg, telecom manager for the Community Health Network, to which IHH belongs.

Are the paybacks real?
Egan and Hartzburg agree that if a network already includes a robust WLAN infrastructure and wired VoIP, the cost of VoWi-Fi should be little more than the price of the handsets. While volume discounts vary, hospitals can buy Vocera badges and Cisco 7920 handsets for less than US$500, including the software license and extra batteries.

In general, though, hospitals are not finding hard-dollar savings. The payoff is recaptured clinician time, and less tangible returns such as enhanced communication and increased staff and patient satisfaction.