The Pinellas County (Fla.) Sheriff's Department is poised to demonstrate how public-safety agencies can transition from total dependence on cellular phones and mobile radios to systems that emphasize Wi-Fi and voice-over-Internet protocol technologies.

The sheriff's department has built a Wi-Fi-enabled network throughout its correctional facility in Clearwater, locating access points in hallways so correctional officers equipped with Wi-Fi-enabled voice-over-IP phones can be reached in the remotest areas of the facility.

“We implemented a wireless network to track the inmates, but there are some areas where we would have to run wires all over the place for phones and data,” explained Tom Baumgartner, a network analyst for the sheriff's department.

The Pinellas County facility holds both transient prisoners destined for more secure locations and a generally less dangerous population of inmates working off shorter sentences among its more than 3100 residents. The walls are reinforced concrete; the cells have bars. Cellular phones are useless and “mobile radios won't get back in there either,” without “a lot of infrastructure to make the radios work,” Baumgartner said.

Baumgartner worked with Cisco Systems' Wi-Fi VoIP phones that are compatible with both Cisco and Symbol Technologies access points; then he used wireless infrastructure provider Wavelink's technology to trunk the system into different voice and data channels to make sure that voice was prioritized when needed.

Baumgartner also plans to use a system that Cisco developed for schools that notifies principals of 911 calls via voice-over-IP phones. That would come in handy “when a deputy has a problem and needs to get on the phone and can't get a radio,” he said.

Currently 61 access points are scattered throughout the multi-building facility, with some in hallways and some connecting buildings. A new $30 million addition will add about 80 more access points, Baumgartner said. While he only has 10 operating phones now, more are on order.

The access points are locked safely out of reach of prisoners who would, given the opportunity, be a little tougher on infrastructure than the typical corporate client. “There is a whole set of infrastructure that is hardened and ruggedized for fierce environments,” said Eric Hermelee, Wavelink's marketing vice president.

In most cases, this hardening is intended for military environments and harsh industry settings like construction sites. A prison setting is unusual, but applicable.

The Wi-Fi system also must overcome the power outages that accompany the frequent lightning strikes the facility takes. Even a short outage causes electronic items to revert to their factory settings. Wavelink's gear automatically reconfigures the system as part of its ongoing monitoring capability, rerouting traffic through different access points to maintain connectivity.

“You can see the mobile devices roam from access point to access point using the MAC address,” said Baumgartner. However, both Baumgartner and Hermelee emphasized that the use of Wi-Fi has its limitations.

“We're looking at maybe taking some traffic off the radios that we have because they're so jammed up all the time it's hard to get on them,” said Baumgartner. “I can use some of the voice-over-IP group calls internally, and that would work really great. Just think of a phone as another mobile unit; it can do group calls. They're really cool.”

But they're not replacing traditional radios. “It's not an either/or,” Hermelee said. “Public safety is augmenting their capabilities and their ability to deliver new applications and take advantage of the high speed and economics of Wi-Fi to augment the infrastructure. That's the transition that's happening.”

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