New standard for seamless WLAN/WAN roaming: is it an answer in search of a question?

In the mobile era, the Holy Grail of tetherless corporate communications is the ability to seamlessly travel among and across business WLANs, WANs, and cellular stations, all the while maintaining data and voice access to business apps.

Three industry vendors with varied areas of expertise have now teamed up to make such levels of access a reality. Motorola, Proxim, and Avaya recently announced that the companies will work to create a standards-based solution--including hardware and software--that will allow business users to maintain a connection when leaving the corporate WLAN, with data transferred to public WLAN or a cell phone network until the LAN is accessible again. While there are a few existing products that support both cellular and WLAN protocols, the new triumvirate, with expertise in critical areas and deep product penetration in key markets, is being watched closely.

Though it has no official name yet, internally the vendors refer to the technology as the Seamless Mobility Solution (SMS). SMS will provide cellular, VoIP, and WLAN connectivity in data and voice products, though initially the focus is on dual-mode cell phones developed by Motorola The jointly developed, standards-based solutions will support contiguous voice and data service to users across enterprise networks, public cellular networks, and public hotspot WLANs based on 802.11 technology (WiFi).

The converged infrastructure solutions, officials say, will tap into a new and widening enterprise market that demands key technologies to boost the performance of enterprise communications. The IP Telephony application will be enabled by Avaya MultiVantage Software; Motorola will create network mobility management components that control the hand-off between local (WLAN) and cellular networks; and Proxim will provide voice-enabled WiFi WLAN infrastructure, quality of service software, and centralized management systems to facilitate hand-offs between access points. Trials of the joint solution are expected in the second half of this year, with commercial rollout expected early in 2004.

"As the only wireless networking company offering integrated, end-to-end connectivity, we are big supporters of convergent solutions such as this," Angela Champness, senior vice president and general manager of Proxim's LAN Division, said in a statement announcing the partnership. "We have already integrated VoIP into our wireless WAN products and this is a logical next step in the development of our WLANs. Businesses will enjoy increased employee productivity and the opportunity for significant cost savings through convergent networks that can scale to their needs."

The technology will support a number of products aimed at corporate users who need to maintain access to their networks while out of the office. These new solutions include a WiFi/cellular dual-system phone from Motorola, Session Initiation Protocol (SIP) enabled IP Telephony software from Avaya, and voice-enabled WLAN infrastructure from Proxim.

This last piece of the puzzle is, perhaps, the most interesting and innovative. In essence, it would allow a user to talk on a mobile phone--using a VoIP session-by sending the voice signal across a WiFi network. The network could then "hand off" the signal to a cellular network or a WAN, based on service availability.

"The vision is to enable mobility for voice and data, enabling a user to cross networks while the application is running," says Leigh Chinitz, chief technology officer of Proxim's LAN Division. "Right now, VoIP is the focus." Chinitz notes that, while the SMS will be standards-based (WiFi on the networking side, GSM and CDMA on the cell side), the companies are working on enhancements that will deal with some of the more thorny problems in dual-mode handset design. "Battery life is an issue when you are on a LAN, and we need to meet user expectations of handset battery life," Chinitz says.

The Dreaded "C" Word

Underlying the technology is the proposition that local and roaming data and voice sessions no longer need to be considered "separate" entities running on separate networks and utilizing distinct hardware. With the advent of wireless networking and public hotspots connected to the Internet, there's much to be gained by combining network access in a low-cost phone that can jump effortlessly from one network to another.

If that sounds like convergence popping up once again, well, you'll get no argument from the three companies. Officials contend that such multi-topology, multi-platform services will increase network efficiencies, enhance communications, and ultimately result in cost savings for business. Cost-savings can be achieved through reduced network management expenses, lower usage charges and device consolidation, officials say. User efficiencies will result from increased accessibility to the business network and greater mobility through seamless wireless access to business networks, applications, and information within or outside of a work campus. These solutions will also provide enhanced communications capabilities, such as on-demand conference calling and speech access to critical business applications such as email, calendars and corporate directories.

Another impetus is the growth in cellular phone use, and the difficulty in getting good cellular signals indoors. "Typically it is the cellular operator's responsibility to expand indoor signal range [by building more towers], but this is expensive and carriers are not doing it," Proxim's Chiniiz says. Since enterprises are building WLANs with VoIP support anyway, Chinitz contends, SMS seeks to expand the virtual enterprise while at the same time freeing up cellular networks for wide area uses, which is what they were intended for.

VoIP Growth Spurt?

The Motorola/Proxim/Avaya partnership comes at what might be viewed as a particularly risky time for a new telecommunications venture. The past several years have been miserable for telecoms, and VoIP in particular has shown more stagnation than growth. "It's been a tough year for telecom vendors and carriers, as capital expenditures have been slashed and network builds have been scaled back," says a new report by Tom Valovic, director of IP Telephony at research firm DC. But, Valovic adds, the long-term prospects for voice-over-packet technology remain excellent, despite the telecom downturn.

"The overall market is projected to increase at a compound annual growth rate of 45 percent to reach a revenue base of $15.1 billion by the year 2007," Valovic notes. "IDC is projecting the best growth in enterprise systems such as LP-PBXs. For this year, the current forecast shows a 66 percent increase in equipment sales to enterprises."

While the new solution from the three companies does rely on wireless carriers for WAN access to some degree, initially the VoIP portion is expected to be handled within the enterprise, using Proxim access points and Avaya software. However, DC feels that telecoms will begin to create and support new enterprise-class VoIP solutions this year, which would be a boon to the three companies' efforts.

"IDC believes that 2003 will present a major window of opportunity for both IP-PBX vendors and carriers looking to roll out IP Centrex and VoIP VPN services," Valovic's report says. "A number of carriers such as Verizon, SBC, and WorldCom have already made key announcements in 2002."

Phillip Redman, a research director at Gartner Group, agrees. "Inevitably, VoIP convergence happens in the enterprise, and then at home," he says. "In 10 years, wireless and mobile local access will be a check-off item for those users that want it-freely supported by every telecom infrastructure provider and integrated onto all platforms." But Redman notes that, as the first effort to promise a seamless handoff from one network to another, SMS may experience some not-insignificant challenges.

"The vendors face some roadblocks," Redman said in a research note. "To succeed, the collaboration must secure buy-in from wireless service providers, once the product is ready for market. In addition, standards are still emerging for WiFi Quality of Service, so first implementations may still rely on proprietary developments." Redman adds that while the vendors have not publicly announced a partnership with any wireless operator, he believes that Nextel has already signed on to the initiative. (Motorola's network systems group, which made the joint announcement, has close ties to Nextel.)

Another potential problem is the varied cellular service contracts that enterprises maintain. As Gartner notes, enterprises often have relationships with a number of wireless carriers to ensure the best possible coverage areas for widely distributed employees. 'This solution would not offer enough to encourage such enterprises to switch," Redman says. "Also, a limited number of phone models will be available, and with the high power consumption of WiFi, we are skeptical about a power management solution."

Lukewarm Hotspots

Another somewhat questionable proposition is the stated goal of the Seamless Mobility Solution consortium to create cell phones that can operate on public WiFi networks. If the VoLP market has been standing still, the public WiFi (or "hotspot") market has been going in reverse. No one has yet figured out how to make money with hotspots, and few users have been willing to pony up the steep subscription fees to use them. Dual-mode handsets are basically unavailable, and few mobile carriers support VoIP services over WiFi.

Some of this may change, however, with the rollout of Cometa Networks, a joint effort by IBM, AT&T, and Intel to create a national hotspot network, announced in December. Proxim's Chinitz, while declining to comment directly on any possible partnership between the three SMS vendors and the Cometa group, nevertheless says that "we are all aware of Cometa, and we are talking to them." Chinitz makes the additional point that, like the history of cell phone service, a critical mass of service areas may be needed before the technology really takes off-the dreaded chicken-and-egg scenario that has become all too familiar in high tech.

Of the three companies, Proxim was the only vendor to have announced a product for the SMS architecture at press time. The company is currently developing Maestro, a wireless LAN platform that enables distributed deployment of wireless-enabled switches at the edge of the network that integrate advanced mobility, security, network management, voice-over-WLAN, and power-over-Ethernet services.

Proxim officials describe Maestro as a "self aware" learning network that constantly monitors network growth and user density, dynamically adjusting bandwidth, access control, quality of service, and other parameters as mobile users roam throughout the enterprise. Among Maestro's expected features are support for roaming across subnets; security and granular access control using a centrally located policy administrator and distributed policy enforcers; and configuration management tools that automatically push configuration parameters from the centralized controller to Maestro switches. Maestro switches deliver access point-specific parameters to the APs, which can be remotely converted from intelligent to light, reducing the cost of deployments, according to Proxim.

Proxim says that its existing access points, including the ORiNOCO AP-2000 and AP-2500, will work with Maestro, once it becomes available later this year.

Are enterprises demanding WiFi-cellular roaming, or is the Seamless Mobility Solution an answer in search of a question? That remains to be seen. But until enterprise-class VoIP and public WiFi hotspots become prevalent, the seamless mobility initiative is likely to remain a technology that targets-and is adopted by-a niche market. This is not to say that roaming among varied wireless networks isn't desirable: It will clearly be a convenience for some highly mobile executives with fancy phones working for large enterprises. The rest of us, however, may have to make do with today's decidedly low-tech solution to poor signal quality: "I'll call you right back."

www.avaya.com

www.cometanetworks.com

www.motorola.com

www.proxim.com