Putting Your Office in Your Pocket

Computerworld - Editor's note: This is the first of a two-part series looking at supporting highly mobile professionals in two modern hospitals with mobile voice and data technology. The second part will look at how these hospitals are leveraging VoIP for internal communications.

"Desktop automation is fine," says Kathi Diver, nurse-manager at 310-bed St. Agnes Hospital in Baltimore, "but what do you do when your staff doesn't have desks?"

The need to resolve that dilemma is exactly why wireless networking is appealing to hospitals, she says. She should know. An early adopter of Wi-Fi, St. Agnes installed its initial 802.11 infrastructure in 1998, originally to support a nurse documentation system. Since then, use has grown steadily throughout the hospital to include access to its Meditech medical application suite, McKesson Picture Archiving and Communications System (PACS) medical image system and an extensive internal VoIP communications system from Vocera Communications Inc. that lets medical staff contact one another throughout the institution.

St. Agnes started with a small Wi-Fi vendor but moved to Cisco Systems Inc. fairly early in its wireless experience. Now, however, it's looking at adding Wi-Fi telephone handsets to its mix, and as a result it is moving to Meru Networks Inc., a small Sunnyvale, Calif.-based Wi-Fi system vendor that offers a central wireless network controller.

"We have always been served well by our network vendors," says Bill Greskovich, the hospital's CIO. "Cisco's a great company. But Meru has some interesting technology in packet switching that manages the network for better results."

One concern at St. Agnes was that weak points in the network might become dead spots in the VoIP system. Most Wi-Fi network managers try to fix these by adding more access points (AP), but that also creates interference between points. To minimize that problem, organizations do extensive coverage plans that can become a major part of the expense of building a network. In hospitals, these are often complicated by the nature of the older buildings at the core of many medical institutions, which often have thick walls with a great deal of steel rebar that interferes with wireless signals. In addition, hospital radiology departments often have lead-lined walls, and hospital buildings tend to have complex floor plans and are therefore harder to cover than normal office buildings.

Meru's answer is its central controller, which manages the network as a whole for even coverage with minimal interference, balancing the APs to minimize weak areas and interference. It also manages the network as a single channel, so that a device sees the entire network as a single AP. This facilitates smooth handoffs between access points for users who may be on a voice connection while moving through the facility, another concern at St. Agnes.