• United States
by Susan Breidenbach

Howdy, pardner!

May 03, 20048 mins
Cellular NetworksNetworking

PBX, WLAN and handset makers step together to choreograph voice-over-wireless solutions.

Today’s nascent voice-over-Wi-Fi market offers mobility-hungry companies a growing array of pre-standard products, often backed by troika partnerships that the handset, wireless LAN infrastructure and PBX players are forming to piece together complete solutions.

VoWi-Fi calls to users

Early adopters deploy voice over wireless to gain mobility and cost savings.

VoWiFi standards situation

Voice over Wi-Fi (aka VoWLAN) refers to the provisioning of IP voice services across 802.11-based wireless LANs. Several IEEE 802.11 working groups are finishing up some key enabling standards, such as 802.11e’s Wireless Multimedia Extensions. Meanwhile, today’s products often use proprietary technology.

It is voice that is driving WLAN deployment, and a lengthening lineup of industry behemoths and innovative start-ups are clamoring for customers. While InStat/MDR expects the VoWi-Fi installed base to more than double this year, from 75,000 to 170,000, it’s clear that supply still outweighs demand.

Those ready to buy must sort through the value propositions that various vendor alliances bring to the table. Or they can turn to Cisco, which is taking on all the VoWi-Fi players with a single-vendor approach. These decisions are being made while the standards bodies still seek common ground for security and quality of service.

“In the absence of complete and usable standards, that’s where you get partnerships,” says Jonathan Cohen, director of product line management for Avaya’s communications appliances division. “We have to do special things to the handsets and have special relationships with the wireless access point vendors to get voice to work over something that isn’t optimized for real time.” Avaya partnered with heavyweights Proxim and SpectraLink.

Wireless handset pioneer SpectraLink is the most sought-after partner in the VoWi-Fi industry. PBX vendors want to offer a range of handset options, and SpectraLink’s product line includes everything from small, stripped-down models to ruggedized devices with push-to-talk capabilities. Now that Symbol Technologies is focused on voice-enabling mobile terminals, the choices have pretty much come down to reselling SpectraLink’s handsets or building your own.

SpectraLink recently enhanced its 802.11 offerings with a docking station that includes an integrated speakerphone and charging cradle. The vendor boasts another asset in its SpectraLink Voice Priority protocol, which is supported by established vendors and WLAN start-ups alike.

Wireless infrastructure options

In choosing a WLAN partner, PBX giants Nortel and NEC rejected market leader Proxim in favor of start-up Airespace. The WLAN switch vendor touts real-time performance (sub-50-millisec handoffs), dynamic radio frequency management, and radio frequency fingerprinting that enables E911 support.

NEC was the first to recognize the potential of Airespace’s technology, inking a co-development deal “before they were even Airespace,” says Paul Weismantel, director of Enterprise Solutions for NEC. The relationship extends far beyond a simple OEM arrangement, resulting in customized product enhancements to quality of service (QoS), handset battery life, security and fast handoff. Other Airespace VoWi-Fi partners do not offer these exclusive technologies.

Airespace caught NEC’s eye because it “is the only WLAN system that manages the RF spectrum dynamically, monitoring everything and changing power and channel assignments to optimize [access point] performance,” Weismantel says.

Although Airespace is still awaiting its third birthday, there’s an even newer kid on the WLAN block. Meru Networks is shaking things up with pre-standard QoS technology that lets its access points support more than 100 clients and handle 30 simultaneous voice calls. The first products hit the market in the fourth quarter of 2003.

“When others talk QoS, they are referring to prioritization,” asserts Kamal Amand, vice president of sales and marketing at Meru. “We manage collisions in the air, doing fine-grained QoS both downstream from [access point] to client and upstream from client to [access point]. No one else does the latter without using proprietary technology on the client.”

Meru’s proprietary QoS technology is implemented in its switches, minimizing the number of devices to be upgraded when the 802.11e QoS standard is completed. The standard is currently scheduled to be released in two phases, with the Wireless Multimedia Extensions slated for the June timeframe, followed by the Wireless Scheduled Multimedia specifications toward the end of the year.

The start-up is partnering with SpectraLink on the handset side, but providing its own support for the various PBXs. “The PBX integration only takes about half an hour,” Amand says. “We are just a transport.”

Meru also has tackled one of the biggest VoWi-Fi handset problems: power. In March, Meru announced sleep-mode drivers it says can more than double talk time between recharges.

The WLAN vendor is joined by a host of other start-ups that are eyeing the VoWi-Fi opportunity eagerly and hope to make up in innovation what they lack in size and market share. These include Aruba Wireless Networks, Chantry, Legra Systems and Trapeze Networks.

WLAN veteran Proxim is building a next-generation Wi-Fi platform designed from the ground up to support voice. With this new infrastructure, Proxim is refocusing on the convergence of VoWi-Fi and the public cellular networks, and working with Avaya and Motorola to develop an environment that supports roaming between LAN and WAN.

Voice client choices

A lot of the waves on the client side are coming from Vocera Communications, which is going after the hands-free niche with a “wearable” device. The Vocera badge can be clipped to a pocket or lapel, or worn around the neck. It is activated by pushing a button, and then controlled with voice commands.

Calls can be made to phone numbers or names, and a one-to-many option allows real-time broadcasts to groups. This can be handy when there is a code-blue emergency in a hospital, a security incident in a retail environment or a line down in a manufacturing plant.

The Vocera badges and application server can operate independently as a stand-alone communication system, but PBX integration is required if they are to send or receive outside calls. Vocera is similarly agnostic to the specific WLAN infrastructure being used.

Softphone specialist TeleSym also is eschewing formal relationships with PBX vendors, and instead using connectivity software that can integrate with any PBX, says Mike Houston, senior product marketing manager. “We will be making some announcements regarding the WLAN infrastructure players in the weeks ahead, however.”

Like the Vocera badges, the TeleSym softphones do not need the PBX to exchange calls with other IP phones within the campus. They use a call registry to make Session Initiation Protocol-based calls. Houston characterizes the TeleSym product as a high-end softphone with quality-management capabilities. “We recognize the logical limits of trying to manage all the voice quality in the network core. We use client-side quality management that complements QoS technology by helping out at the edge.”

The client everyone is waiting for is the dual-mode phone that will be able to roam between the Wi-Fi and public cellular environments. Motorola announced its Seamless Mobility device in conjunction with Avaya and Proxim, and is working with NEC.

Motorola has demonstrated a prototype that is roughly the size of a cell phone, and the company claims to have solved the battery-life problem. The other major challenge was fitting a multi-band radio into the device.

“There are two 802.11 spectrums inside it along with a GSM spectrum,” says Chris White, director of business development and alliances for Motorola’s seamless mobility group. “Consider the antenna; you need to accommodate all those frequencies. These were not small hurdles to overcome.”

Motorola expects to release the phone before year-end, and White says people will be “pleasantly surprised” by its price, but declined to elaborate.

An estimated 40% of the U.S. workforce is now mobile, making it ripe for VoWi-Fi. But, existing products are full of proprietary shortcuts, and mix-and-match interoperability is probably years away.

“IP telephony and WLANs are still plagued by their own immaturities, which get compounded when the two are combined,” concludes Chris Kozup, an industry analyst with Meta Group. The industry is taking a technology designed for latency-forgiving data traffic and trying to re-engineer it to meet real-time voice requirements. Major issues that remain include security, QoS, management and scalability.

The cost of handsets is another inhibitor. “We thought the price would come down to $500, but the average street price in 2003 was $566,” says Gemma Paulo, senior analyst for In-Stat/MDR. “SpectraLink is not budging, and probably won’t until the QoS standard kicks in.” And 802.11e leaves plenty of unanswered questions.

On the bright side, 10% of users with WLAN infrastructures are running some voice over them, and another 50% say they are considering it, according to an In-Stat/MDR survey of 358 businesses. This may indicate a groundswell of interest in pre-standard solutions.

“Enterprises with a lot of mobile employees within the campus have to ask themselves, ‘Who’s using it already, and why?'” says Phil Redmond, an industry analyst with Gartner. “What is my competition doing, what is my industry doing, and is my company behind the curve?”

Breidenbach is a freelance writer in Nevada. She can be reached at