The Advent of the Hallway Warrior

In-house wireless voice-data convergence is bringing cost savings, greater functionality The convergence of wireless LANs and IP telephony has the potential to create a new corporate breed: the "hallway warrior," connected to the organization and the world by a single voice/data wireless device. Voice over Wireless LAN (VoWLAN) combines the familiar benefits of in-building mobile calling with those of running both voice and wireless over a single, centrally managed in-building network and of utilizing integrated voice-data applications. The promise of VoWLAN is embodied in portable handsets that can encompass the features of a wide range of devices: desk telephones, pagers, PDAs, laptops, walkie-talkies, RFID readers, barcode scanners and more. In-building wireless is far from new. Walkie-talkies have been with us for decades, and are still used, for example, by fast-food workers. Nortel’s Companion and similar systems that linked the mobile handset to the PBX were widely adopted in the nineties. Telus’s push-to-talk Mike service has won adoption in the construction industry and some other sectors. There have been efforts to equip high-rise office towers with cellular transmitters for more effective in-building cellphone use. But all these options face major limitations, including the cost of airtime for cellular options and the retreat of the circuit-switched technology on which the wireless PBX was based. Wireless IP TelephonyVoice over WLAN is emerging as the wireless IP-PBX—that is, the wireless form of corporate IP telephony. Despite some growing pains, it is becoming the new standard for in-building wireless. Worldwide sales of VoIP Wi-Fi handsets reached US$45 million in 2004, as 113,000 units were shipped, according to Infonetics Research. The research firm predicts that VoWLAN is poised for takeoff. Until now, "most of the activity has been in markets that don’t necessarily get a lot of attention," says Ben Guderian, marketing vice-president for the dominant Wi-Fi handset supplier, SpectraLink Corp. of Boulder, Colorado. "We’ve been kind of a low flyer—health care, retail and what we classify as industrial, which is primarily manufacturing, distribution centers, warehouses, those kinds of things," Guderian says. But now, widespread wireless LAN adoption in the general enterprise is "starting to create a little more horizontal market." Why Wi-Fi?For many applications, the benefits of VoWLAN as a form of in-building wireless are self-explanatory. "The primary benefit of Voice over WLAN architecture is mobility," says Tracy Fleming, Avaya Canada’s National IP Telephony Practice Leader. "In the hospital, where it has really taken off, nursing is the key application. The nurse walking down the hall can actually see on her handset that Mr. Smith in room 1234 has pushed the button and can take the call." Thanks to voice-data integration, there is no barrier to using such a mobile device not only to take the call but to access patient records and note down observations. Voice over Wi-Fi can be enhanced by "find me, follow me" applications using spatial location or location based tracking. In this way, customer calls can be routed directly to a roving employee who meets appropriate criteria: present, available, familiar with the customers, trained on the solution, or closest to the inventory. According to Andrew Fisher, president of Ottawa-based NewHeights Software, "The real win is when you build location-based tracking into your call routing, so calls are completed according to where you are, when you are there, who you are with and what you are doing." Quality of ServiceBut when wireless voice calls are running over a shared voice-data network, measures are needed to assure Quality of Service (QoS)—that is, to give priority to voice. "There are huge Quality of Service issues in traditional data networks," says Fleming. "When you move into wireless LAN, you actually compound the problems. Traditional wireless LAN technologies like 802.11b are essentially shared systems, so there is no Quality of Service metrics in those systems at all. That is why we are moving quickly into newer technologies like 802.11a which is preferred for Voice over Wireless LAN technology, and 802.11i, which addresses security and some QoS concerns," he says. VoWLAN Quality of Service makes networks designed for data assign voice packets a higher priority. SpectraLink Voice Protocol (SVP) has become a de facto "pre-standard standard," licensed to Mitel, Nortel, Avaya and others. It will probably soon be replaced by a standard, 802.11e, that will not only allow prioritization of voice traffic over data but also allow network managers to anticipate scheduling for heavy loading of access points. Ready for Wireless Voice?Speaking in February to the VoiceCon 2005 conference, George Sullivan, Avaya’s chief technology officer for global managed services, said the typical enterprise WLAN today is not ready for voice. To make it ready, "you’re going to spend 15% to 30% more than you would have ordinarily for infrastructure." In most situations where the network is several years old, says Brantz Myers, Cisco Systems Canada’s director of enterprise and voice marketing, "we would typically see a pretty substantial network refresh required" at the start. "Once we do that then we would just apply wireless access points into the ceiling." Positioning the access points for optimized coverage is, of course, a challenge in itself. Voice traffic does not require a great deal of bandwidth, but it needs to operate in real time, so many locations will require additional access points to maintain Quality of Service. Coverage surveys should also take into account any special requirements. NewHeight’s Andrew Fisher points to a large warehouse VoWLAN implementation in France that had to be substantially reconfigured because access points could not hand off calls quickly enough to workers speeding by on in-line skates. "You need to think about how many wireless phones you’re going to have on the floor," says Myers. "Are there any areas where people tend to cluster? For example, a nursing station is where you might have several people all standing at the same time with phones on their belt, whereas around the ward they would be distributed more sparsely." SecurityStung by the inadequacies of an early standard, Wired Equivalent Privacy (WEP), WLAN managers are rightly concerned about security. However, Wi-Fi Protected Access (WPA) has provided some comfort, and the recently ratified 802.11i should provide more, along with a measure of flexibility. 802.11i can authenticate users by name and password, or dynamically apply shared key sets and user policies that change with users as they roam from location to location. Rohan Mahy, chief voice architect at Airespace, a wireless LAN company, told VoiceCon 2005 that VoWLAN security should be as ubiquitous as the rest of the infrastructure supporting the mobile device. InteroperabilityInteroperability is another critical VoWLAN factor, because the technology will be installed in environments with multi-vendor networks. "That is what people want to have," says SpectraLink’s Guderian. Compatibility is important, both within the wireless LAN infrastructure and for communicating with the telephone switch. "Those are two areas where we have made a lot of investments in order to make this all work," Guderian says. Good standards are in place on the wireless LAN side, he adds. "The 802.11 standards, in their various flavours, dealing with things like security and Quality of Service are well done and have good industry backing. On the telephony side, unfortunately, we are dealing with a bunch of proprietary protocols." Proprietary protocols from vendors such as Nortel or Cisco predominate over Voice over IP standards like SIP, Guderian says. "To us, it is somewhat of a competitive advantage, because we’ve established the relationships with the companies that allow us to support their protocols. We have done the proprietary protocols for Cisco, Avaya, Nortel, Alcatel and others, so that means we have good interoperability with a depth of integration that gives you all the features, bells and whistles that you expect to have on a digital Voice over IP telephone set." Has VoWLAN’s Hour Struck?At VoiceCon 2005, Avaya’s George Sullivan advised potential VoWLAN users to resist the temptation to load mobile devices with features, and perhaps most importantly, to avoid using senior executives as guinea pigs for the new technology. SpectraLink’s Guderian agrees. "The areas where we have had success owe a lot to simplicity," he says. "We have a handset that isn’t filled with the bells and whistles that you would find on a consumer cellphone, but is much more tied to the business features you’d find in an office environment or for use in a hospital." That makes a huge difference, Guderian says, "because people can use it like their ordinary telephone. They understand how to put a call on hold and pick up another call, and they don’t have to learn a whole new paradigm around that." Avaya’s Tracy Fleming agrees on the importance of avoiding complexity. Voice over Wireless LAN will grow explosively, he says, "once it becomes brutally simple. We’ve seen a lot of these technologies in the past and they’ve been relegated to the technology elite, because it took two or three steps to make them work. When I can put it in a doctor’s hand and they don’t ever have to worry about it, that is when you will see mass adoption." The shape and size of wireless devices is an important factor. Vocera Communications Inc. of Cupertino, California, has sold its "badge" solution to more than 80 hospitals. The medical worker pushes a single button on a "Star Trek"-style device clipped to her tunic to activate voice-recognition software and complete an outgoing call. Incoming calls, announced by a tone and the caller’s name, can be accepted or declined. VoWLAN technology will bring organizations a greatly expanded range of mobility choices and, in many cases, significant cost savings. But it also offers, at this stage, the challenge of system complexity in a fast-changing technical and standards environment. To unlock this potential for the broad enterprise market, vendors must achieve greater simplicity and reliability. In a marketplace that promises to be hotly competitive, progress in this direction should be rapid. But any organization considering VoWLAN must consider its hazards as well as its promise, in the framework of a careful comparison of vendor offerings. Dual-System Handsets Will Suit Both Road and HallwayDual-system PBX wireless handsets that combine cellular and Wi-Fi capability will equip users to be both hallway and road warriors, with a single device, reducing airtime charges while increasing convenience of use. The handsets are designed to transition calls without interruption from the enterprise wireless LAN to the cellular network beyond its walls, and vice versa, and to run both modes off a single phone number. Motorola’s CN 620A leading contender in this market is the CN 620 handset from Motorola, with Avaya and Proxim providing the necessary gateway/wireless access point and management software systems. The product’s Canadian launch is planned for later this year. Avaya Canada’s Tracy Fleming illustrates the possibilities in terms of a BMW sales representative: "The system finds me wherever I am—maybe I take the call on the Don Valley Parkway, but I drive into the BMW dealership at the base of the 404. As I walk into the building, the call automatically switches from the cellular network to the wireless LAN without dropping the call." In reverse, the building’s Wi-Fi network would deliver calls to the cellular device. This is not a costly specialized product for the call centre or senior executive, Fleming says. "It is general productivity functionality for the average salesperson." The system is GSM-only, and Rogers is the only Canadian cellular provider on that standard, so the cellco’s cooperation would seem necessary. Cellular networks are of course engineered to block access from unauthorized devices. Some of the carrier’s revenue comes from calls made on company property, and this would be lost in a dual-mode set-up. Cellco ResponseRogers has no comment for now, but it is not obvious they will embrace the dual-system devices. Yet according to Avaya’s George Sullivan, GSM providers not only have the capacity to support cell handoffs to an enterprise PBX, they have an incentive to do so, because the more employees who have a dual mode device, the more minutes of cellular airtime they will use. Just as cellphone users don’t return to their desks to make important calls, dual mode users won’t wait until they are within range of their corporate LAN to make their calls, Sullivan says. Hot Spot Link-UpDual mode handsets also open the possibility of carriers affiliating with wireless "hot spot" providers to provide billing options for uninterrupted connectivity. As Frost and Sullivan’s Ron Gruia says, "Once you do find that carrier, and once that model is in place, then this is going to be very powerful. Then you will see very interesting applications." Additional pressure on GSM-based cellular providers may come when the Motorola, Avaya and Proxim consortium release their planned CDMA version of the CN 620. —RB

The Advent of the Hallway Warrior

News | 03/29/2005 5:00 am EST

To keep reading, get a free trial.

Already a Subscriber?

Reuse & Permissions

Inside The Wire Report

Information

Hill Times Publishing

Get in Touch With Us