Flexible VoWiFi Technology Comes of Age

Wireless mobility boosts productivity and increases public safety in Marion County, Fla.

Wireless voice technologies — only recently considered too exotic, unfinished, hopelessly expensive or otherwise impractical — are rapidly becoming a mainstream flexible alternative to wired infrastructures.

Voice over wireless data networks (VoWiFi) is a piece of the expanding communications quilt of overlapping technologies, offering people ubiquitous connectivity regardless of their location or the type of device they’re using. This flexibility is starting to have a dramatic impact on the way that government organizations deliver services to their citizens. It can streamline inspection services, empower caseworkers, increase public safety and generally make government more efficient and responsive.

Florida’s Marion County recognized the benefits of wireless flexibility and voice/data convergence early, implementing its first wireless LANs in the mid-1990s before the 802.11 standard was ratified and embracing Voice over Internet Protocol in 2000. Once these technologies were in place and manufacturers started delivering faster Wi-Fi based on 802.11a, VoWiFi became a natural extension.

“It’s a lot cheaper and easier to put in wireless, and the wireless technology is also just a lot more flexible,” says Hugh Honts, assistant director of the information systems department for the Marion County Board of County Commissioners. “A lot of our buildings are donated or were confiscated and aren’t always easy to retrofit or cable.”

It was a relatively simple matter to add Wi-Fi phones to the existing IP telephony environment, which is based on Avaya’s S8500 Media Server, Communication Manager, and Converged Communications Server. The county now uses VoWiFi primarily to enhance customer service and public safety, and about 20 percent of its 94 sites are equipped with it. These include the public-library system, information systems, building planning, fleet management and the agricultural center.

The fire department’s command vehicles and command-center trailers are equipped with a VoWiFi infrastructure that uses satellite or cellular networks to provide voice service at disaster sites. The trailers can establish a virtual private network that connects to the main county network or — if such a connection is not available — operates as a standalone voice system with PBX capabilities.

VoWiFi is also being used to enhance communications outside of emergency services. Librarians can roam the stacks with wireless phones, and employees in the agricultural and fleet-management departments can make or receive calls from anywhere within their large facilities. Permitting-services agents can walk out among customers and take their phones with them, and fieldworkers with softphones and headsets can use the built-in Wi-Fi technology in their notebook computers.

Phone Preferences

There are three basic handset options for VoWiFi: a PC-based softphone, a single-mode Wi-Fi phone and a dual-mode phone that can access both cellular and Wi-Fi networks. The softphones — software that basically turns a notebook or other mobile device into a telephone — are the cheapest alternative and provide very good voice quality, Honts says. Softphones are used by mobile Marion County employees who take their notebook computers everywhere; other mobile employees are equipped with wireless handsets designed specifically for use with Wi-Fi data networks.

Marion County is not using dual-mode phones yet, although they are clearly the way of the future. Infonetics Research reports that Wi-Fi phone sales leveled off a bit in 2007, probably because of the advent of dual-mode phones. And Infonetics expects the number of fixed/mobile convergence subscribers to skyrocket, from 188,000 in 2006 to 38.2 million in 2010. Users won’t have to deal with multiple phones, numbers and voice-mail interfaces, and a Frost & Sullivan study indicates that organizations will save 15 percent to 40 percent on cell-phone charges.

At the moment, though, dual-mode phones are still quite expensive, and seamless roaming between cellular and Wi-Fi networks remains an issue, cautions wireless-industry analyst Joanie Wexler. “The big problem is the cellular guys,” adds Guy Clinch, a solutions director for government markets at Avaya. “When customers move onto the Wi-Fi networks, they aren’t burning carrier minutes. It’s a market problem, not a technology problem.”

Siemens stands out among the big voice-system vendors as the first to ship technology that seamlessly moves a voice session from one type of network to the other when users talking on mobile phones walk into and out of Wi-Fi-equipped buildings. Its HiPath Mobile Connect client software is installed on dual-mode phones and is carrier-agnostic. In other VoWiFi platforms, such seamless roaming is not yet supported. Dual-mode phones can be used, but in one mode or the other. In October, Avaya delivered seamless roaming in partnership with Nokia, but it is available only on Nokia handsets.

“We demo’d some of the dual-mode phones, but we still don’t have a real reason to buy them,” Honts reports. “However, we are in the middle of a $45 million expansion of our judicial center that has us rethinking the dual-mode phone issue. The judges and their staffs circulate among five different counties, including ours, so it might make sense for them to have dual-mode phones.”

Meanwhile, Marion County is integrating regular mobile phones with its voice infrastructure through Avaya’s EC500 Extension to Cellular solution. The product basically pushes PBX functionality out to cell phones, giving employees complete access to full desktop-phone features and letting them use a single number and single voice-mail system across mobile and desktop phones.

“We can even change our cell-phone carrier behind the scenes, and no one knows the difference,” Honts says. “We just reprogram the Avaya IP PBX, and the cell phones still ring when someone calls the office number.”

Pitfalls and Payoffs

Voice is a critical application, and many existing IP telephony and Wi-Fi infrastructures can’t support it in their current state. “Make sure your VoIP is working well before you start branching out to new media,” advises Honts. “And we run voice over 802.11a rather than -b or -g, so we don’t get interference from anyone who walks into the network with a laptop.”

Wexler advises organizations to think ahead about their phone strategy. For example, is there any need to buy wired IP desk phones for areas that have Wi-Fi coverage? And how many different phones do you want to buy for each person? While VoWiFi can be very cost-effective in smaller environments, its scalability as a complete replacement for wired voice across large environments has yet to be proved.

Also, while it may seem simple and inexpensive to add voice to Wi-Fi, data wireless LANs typically don’t cover every nook and cranny. For example, you don’t need data coverage in a stairwell, but people might want to maintain voice connections there. “Some organizations calculate that it would cost them half a million dollars to upgrade their Wi-Fi infrastructure for voice,” says Wexler. It might actually be cheaper for such organizations to pay for the extra cellular minutes or even implement an in-building cellular solution.

Security can also be a stumbling block. “We expected [wireless] LAN technology to take off a lot faster than it did, and security was one factor holding it back,” recalls Nora Freedman, a senior analyst with IDC. Organizations need to make sure history doesn’t repeat itself with VoWiFi. For example, security can be enhanced by segregating voice traffic on a separate virtual LAN. Then voice calls can never go anywhere else on the wireless LAN, and guests coming on to the VoWiFi network can’t get anywhere but to the IP PBX.

Freedman also cautions organizations to consider the need to record voice calls for quality assurance or auditing purposes. “We haven’t heard much about such capabilities in VoWiFi,” she says.

Above all, it is important to make a good business case for VoWiFi. “It is expensive to put those phones in people’s hands,” Honts says. “But by doing so, you might be able to save hiring two extra people or increase public safety quite a bit.”

In fact, says Avaya’s Clinch, VoWiFi’s wireless flexibility and IP recoverability improves public safety and homeland security by enhancing the Internet’s inherent survivability. “Keeping people chained to desks in rows of cubicles is not only inefficient but also potentially dangerous,” he says. “Government can’t afford to have a single point of failure these days, and wireless voice solutions liberate organizations from fixed facilities and offer multiple connectivity options.”

Dec 13 2007