Internet protocol technology that merges multiple voice and data functions over an 802.11-enabled Wi-Fi network is expected to take off in 2004 and new versions of the old standby — walkie-talkies — will go along for the ride. On top of that, technology prices will come down as capabilities go up.

But make no mistake about it; these will not be your local Civil Defense warden's walkie-talkies — nor will they need to be. They'll be used in large enclosed spaces — retail environments, warehouses, hospitals and government facilities — as part of a growing communications scheme that uses the 802.11 wireless network.

The types and styles of VoIP walkie-talkies range from traditional units that clip onto a belt and enable peer-to-peer conversations to Star Trek-like communication badges that hang on lanyards or clip to shirt pockets. Some units receive text messages — sometimes detailed — and some can function as retail scanners. The universal drawback is that none of them operate outside the Wi-Fi network.

“Certainly, a [traditional] walkie-talkie works great for people who leave the facility and walk out into the parking lot,” said Ben Guderian, marketing director for SpectraLink, which includes VoIP walkie-talkies among its IP-enabled phone product line. “In the Wi-Fi scenario, you have to have coverage out into those areas and sometimes that can add quite a bit of cost to put access points outdoors.”

On the other hand, Wi-Fi networks are superior in several aspects.

“If I'm down in the basement of a high-rise building and you're on the 70th floor, it's unlikely we'll communicate with a walkie-talkie. But if I have Wi-Fi access points throughout that entire building, then we can communicate anywhere because I communicate with the nearest access point,” Guderian said.

Vertical Networks implements the IP PBX, call routing and call forwarding — as well as keeps track of calls — for large retailers that install and use Wi-Fi for voice and data communications. The company uses SpectraLink phones integrated with walkie-talkie functionality to deliver phone-like functions such as Caller ID and voice messaging.

Multi-functional VoIP phones with integrated walkie-talkies can also link back to the PSTN for two-way conversations with the outside world, said Scott Pickett, Vertical's co-founder, chief technology officer and executive vice president. Such functionality can be used to keep roaming floor managers in instant touch with customers calling with inventory questions.

“In the retail area, it's about customer responsiveness,” Pickett said.

In the VoIP walkie-talkie space it's also about features and cost, of course. Pickett sees “an onslaught of new wireless IP phone vendors from Southeast Asia” hitting the U.S. shores this year with “very inexpensive designs that are going to be really well received by the market.”

These new phones will be met by existing U.S. products from companies like Symbol Technologies, whose product line currently includes VoIP walkie-talkies that split frequencies into 255 individual channels.

“In walkie-talkie mode in a wireless infrastructure, these channels are partitioned by groups,” explained Rich Watson, Symbol's telephony product marketing director. “Each person within a group can belong to one or more of these channels.”

While some vendors cited excessive ongoing background voice traffic as a reason to deploy VoIP walkie-talkies with individualized addresses, Watson said “one-to-many functionality ends up being a feature that our customers rely on.”

Thus, Symbol customers can split the signals into channels that represent different departments within the organization. “You get a lot more functionality over a standard walkie-talkie,” he said.

Symbol's product even lets multi-taskers monitor multiple channels and, unlike most walkie-talkies, offers a minimal level of audio replay.

“If you're interacting with a customer and some audio activity comes in, you reach over and punch one of the hot keys and it will replay the last 30 or 60 seconds of audio,” he said.

Perhaps the most futuristic of the VoIP-enabled walkie-talkies comes from Vocera Communications, a three-and-a-half-year-old California company that sells communications “badges” that clip to lanyards or shirt pockets. These badges are voice-enabled units that permit the following: person-to-person conversations; outgoing calls through voice recognition and the IP PBX; and the reception of incoming calls. The units also contain — of course, they're part of an IP network — a small LCD for text messaging.

“We don't think of ourselves as a walkie-talkie,” said Brent Lang, Vocera's vice president of communications. “We have some of the aspects of a walkie-talkie — particularly the broadcast capability — but unlike a walkie-talkie, which is always broadcasting to everyone, our broadcasts are very directed.”

According to Lang, Vocera has combined the best aspects of a cell phone, a walkie-talkie, a hands-free speaker-phone and a text pager in one system.

“The difference between our radio and a walkie-talkie radio is that our radio is transmitting IP packets rather than transmitting broadcast-type traditional radio frequency packets,” he said. “From a wireless perspective, there's a lot of similarities.”

And a lot of dissimilarities. Because they're part of multi-function data units, most VoIP-enabled walkie-talkies have more features than traditional non-IP radios. They're also restricted to indoor environments and networks that operate in the crowded 2.4 GHz spectrum. While many interference problems have been overcome, concerns exist that the units will collide with laptops transferring data, although Lang said that has not been the case in the locations where Vocera has deployed products, sometimes to more than 1000 users.

Another potential problem concerns cost. While VoIP-enabled walkie-talkies are “relatively easy to implement,” they're probably not the most cost-effective way to proceed, admitted SpectraLink's Guderian.

“Our approach could be more expensive because you have to have a Wi-Fi network to support this,” he admitted. “If you think about a traditional two-way radio, I might just need to buy a couple of low-end radios and I don't have to have any infrastructure to support those.”

Even so, some larger facilities using trunked two-way systems and base stations also can get pretty expensive.

Add it all up and voice services — almost an afterthought for Wi-Fi in its earliest stages — should give the technology the lift it needs to soar in 2004.

“If you had asked me two years ago, I would have said voice never sells the Wi-Fi network — ever,” said Symbol's Watson. “We're now seeing companies at the point of making a Wi-Fi decision where voice becomes a key factor. It's not the deciding one, but it becomes a key factor.”

And VoIP walkie-talkies are a factor in that.