Even though a new standard has emerged that adds quality of service to voice over wireless LAN (WLAN) deployments,...
one company is demonstrating that there can be advantages to nonstandardized VoWi-Fi QoS.
Two years ago, Pacific Sunwear of California Inc. opened a new headquarters in Anaheim, Calif., that was three times the size of its previous office. Managers who used to be easy to reach were often away from their desks for long periods during the day. Phones went unanswered, and voice mail messages went unheard.
"People would call someone, leave a message and then never hook up with them," said Ron Ehlers, Pacific Sunwear's vice president of information services.
The retail clothing company considered giving cell phones to managers, but they were too expensive and coverage was often inadequate. Two-way radios were also an option, but they could not interface with the phone system. Eventually, Pacific Sunwear decided to add voice calling to its WLAN system.
At the beginning of 2002, the company deployed wireless VoIP phones. Managers were able to carry their phones with them, making them available throughout the building. The problem was solved, Ehlers said, for about six months. By mid-year, the office's wireless network was clogged by voice traffic.
"We had a problem with access points getting overloaded with traffic," Ehlers said. "When that happened, we had real problems with dropped calls."
About six months after the wireless VoIP implementation, Ehlers turned to a Sunnyvale, Calif.-based vendor, Meru Networks Inc. Meru offers a nonstandard WLAN system that is designed to help businesses deploy a large number of wireless phones on their networks, which avoids problems with dropped calls and poor call quality.
Meru's network of access points appears as a single AP to a client trying to log on and to the centralized controller that manages the network. That way, there are no problems when roaming between access points. Meru's system can see all of the calls and data traffic trying to access the network, and allocates space accordingly.
Because of this approach, there is no interference between the access points either, something that can be problematic in large deployments.
Joel Vincent, a director of product marketing with Meru, said the 802.11e standard does not address many of these issues. The standards-based approach, Vincent said, simply makes all the phone transmissions more aggressive. Therefore, after a certain number of phones try to access the network, they simply cancel each other out.
And access points will still interfere with one another, he added, especially 802.11b/g access points that have only three channels to work with.
But William Terrill, a senior analyst with Midvale, Utah-based Burton Group, disagreed. With one of the iterations of 802.11e, access points have different priorities for traffic, Terrill said. Given the kinds of deployments that are occurring today, he said the 802.11e approach should be sufficient.
While Meru's nonstandard approach allows access points to handle 60 wireless phone calls at a time -- twice as many as an 802.11e approach would allow -- the added capacity isn't significant because most companies don't need it, Terrill said.
Despite Pacific Sunwear's success, Rachna Ahlawat, a senior analyst with Gartner Inc., said many businesses shy away from investing in nonstandards-based technologies.
"If you have an older WLAN infrastructure, you have to throw thousands of dollars worth of equipment away" in order to implement voice over WLAN, she said. "Then you have to install Meru equipment on top of that."
Still, Pacific Sunwear had little choice but to take a proprietary approach. At the time of the deployment, 802.11e didn't exist, and Ehlers said ripping and replacing old equipment for Meru's equipment made good business sense.
"I knew it was proprietary going into it, but it solved a business need," Ehlers said.
Craig Mathias, a principal with Ashland, Mass.-based research firm Farpoint Group, said businesses should be more concerned with solving a business need than putting off that solution until a standard arrives.
But even Ehlers said if he were deploying the system today, he might make a different decision.
"In general," he said, "I'd prefer a standard, if it was available."