Remote managers brace for Bluetooth

May 14, 2001 —

During the next year, all kinds of equipment used by remote workers will begin sporting a short-range radio interface called Bluetooth. Get ready for some toothaches.

Bluetooth is starting to emerge in headsets and cell phones and in adapter cards and interfaces for handhelds, desktops, laptops and printers. Research firm Cahners In-Stat, of Scottsdale, Ariz., predicts 100 million Bluetooth products will ship next year, leaping to nearly one billion in 2005. But potential problems abound, including partial security, no standard roaming feature, buggy interoperability and interference with wireless LANs.

Originally conceived as a wireless replacement for cables, Bluetooth now is being touted as a voice and data wireless network, even an alternative to 802.11b wireless LANs. The latter is a controversial claim not only because of Bluetooth's design, but also its 30-foot range, 1M bit/sec throughput, and a limit of seven simultaneous connections. But many IEEE groups are putting the final touches on a set of 802.15 standards defining personal-area networks, the core of which is the Bluetooth specification.

Britain's Red-M offers an example of a Bluetooth net. Its Linux-based 3000AS, a small, $3,000 device, accepts up to seven Bluetooth connections and forges a wide-area VPN link, using ISDN or DSL, between two locations. It incorporates a Web server and has an administrative program that remote network managers can access from a browser and set up user IDs and access rights. Axis Communications of Sweden offers a similar product.

It seems incredible a wireless link of less than 1M bit/sec would be viable, but for remote sites it could be, compared with 56K bit/sec for fast modems and 144K bit/sec for ISDN links. But initial Bluetooth products will raise potential problems for IT groups.

For one thing, Bluetooth's security is partial, focusing on encrypting data transmissions. The specification supports 128-bit encryption, says Graham Carter, Red-M's product marketing manager. He says, Bluetooth can be configured so users enter a personal identification number to identify themselves, but it's still unclear to what degree that will complicate the users' interaction or slow performance.

Bluetooth also lacks the superior security features basic to 802.11b wireless LANs, says Charles Dittmer, director of communications technology for Compaq's commercial notebook division. "It's not really a wireless LAN."

And Bluetooth currently doesn't support roaming -- the ability to keep a connection and a session intact as you move through a wireless voice or data network. If you move outside your group of eight Bluetooth devices, called a "pico net," your device has to negotiate a new connection. Bluetooth vendors are building roaming features, but none are part of the specification.

Interoperability may also be a problem for some of the first wave of Bluetooth gear. Users may find they can't transfer a file or receive a phone call, perhaps because the manufacturers used different versions of the Bluetooth specification or faulty drivers. Vendors say they're quickly moving to Version 1.1 and say interoperability bugs have been fixed.

But if 802.11b wireless LANs are already deployed in branch offices, there's a chance of interference when Bluetooth devices show up because both radio technologies use the 2.4-GHz band, already crowded by microwave ovens and cordless phones. Vendors also claaim when devices using different technologies are near each other, users of either might see performance slowdown, but no packet loss.

One other issue to watch is the number of Bluetooth "profiles" a device supports. Each profile describes a different Bluetooth use or application, such as file transfer. Unless both devices support the file transfer profile, you can't perform that action.

The profile problem
While Bluetooth allows for a range of capabilities (called profiles), not all Bluetooth-enabled devices include all these nine profiles.
Generic access: The foundation for discovering and connecting to another Bluetooth device.
Service directory application: Describes how an application on one device can find and use applications on another.
Serial port: To set up an emulated serial cable connection between two peer devices.
Synchronization: Lets two devices update and merge data such as appointments and phone numbers.
Dial-up networking: Lets a Bluetooth device wirelessly connect to a modem.
LAN access: A Bluetooth Network World