Avaya’s vision of seamless roaming from Wi-Fi to GSM is still just a vision

One of the major topics of discussion over the past year has been the vision of a handset that lets users make phone calls on internal wireless networks and continue talking while they’re on the cellular network.

Seamless roaming is more than a dual-mode handset with an 802.11 card that lets

users connect to Wi-Fi hotspots or internal wireless access points, and to the cellular networks. Seamless roaming would allow a salesperson, for example, to talk on a cell phone outside a building, enter the building and have the call connect to the internal wireless local-area network and then disconnect from the cellular network.

If you were under the impression that such services were already available, it’s not because you’re hallucinating. It’s probably because you remember Avaya’s big announcement last summer, in which the equipment manufacturer said it would resell Motorola’s CN620 handset to corporate users in North America by the end of 2004.

The launch has since been delayed to next year (please see story, page 24). By contrast, Cisco Systems Inc. has been relatively quiet on seamless roaming; executives will only say they’ll make announcements in 2005.

Making seamless roaming work is easier said than done. Internal wireless networks based on IEEE 802.11 are completely different from cellular networks based on either global system for mobile communications (GSM) or code division multiple access (CDMA). Making a handset that works on both networks (such as the HP iPaq Pocket PC h6315) is one thing.

Getting a device like the Motorola CN620 to roam between the networks is a much more difficult task. For one, you’d have to find a carrier to offer a service plan on its network. The CN620 works on GSM networks only, and Rogers Wireless Inc. is the only Canadian carrier offering GSM to the business market. Rogers executives have said they’re watching this technology but have yet to announce plans to offer a service. If a vendor launches a seamless roaming product that works well, it would probably be the biggest networking news story of 2005. Otherwise, it will remain no more than a vision.

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