Information on Bluetooth

Apart from the "big three" 802.11 protocols, users and installers of WiFi really don't need to worry about many other protocols (except for Bluetooth, which can prove useful in many products that connect with your WLAN, such as personal digital assistants or smart phones). I present just a few of the more interesting standards here in brief to give you an idea of the scope of standardization and the direction that wireless may be heading.

802.11i

Experts have exposed weaknesses in the current Wired Equivalent Privacy (WEP) algorithm implemented in current WLANs. 802.1li is a new security supplement to the 802.11 MAC standard. 802.11i will address security holes in the 802.1 la, b, and g protocols and improve encryption, key management, distribution, and user authentication. This standard is worth remembering, because these improvements to security may be available as firmware and later hardware upgrades for your existing Wi-Fi network.

802.11n

IEEE has recognized the 802.1 in working group, which has begun investigating the next-generation wireless standard in the 802.llx wireless standards family. 802.1 In is still approximately three years away, but reportedly will provide over 100 Mbps throughput. That is 100 Mbps of actual throughput, not a data rate. For example, the data rate for 802.llg is 54 Mbps, but the actual throughput is typically half of that.
Bluetooth and 802.15.1

Bluetooth is a wireless personal area networking (WPAN) technology developed by the Bluetooth Special Interest Group (founded by Nokia, Ericsson, IBM, Intel, and Toshiba). Its goal is to enable users to connect many different computing and telecommunications devices easily and simply, without the cables. It operates in the unlicensed 2.4 GHz band of the radio spectrum. Developers named Bluetooth for the Danish King Harald Blatand (Bluetooth) who unified Denmark and Norway in the tenth century. Like King Bluetooth, the Bluetooth standard means to unify; in this case, the telecom and computing industries.

Bluetooth does not compete directly with 802.1 lx standards; its range is too short and its throughput speed too slow (1 Mbps) to fill 802.11x's shoes. Bluetooth devices can coexist peacefully and in some cases interoperate with a Wi-Fi network. Bluetooth is a complementary standard to 802.llx.

Whereas Wi-Fi technology replaces Ethernet cables and connects computers in a WLAN, Bluetooth connects peripherals without all those annoying cables. Keyboards, optical mice, printers, digital cameras, and PDAs mat employ Bluetooth are already available. All of these devices can communicate and operate without user intervention. The devices know how to connect and do it by themselves.

Bluetooth devices connect to create small ad hoc networks called piconets. In a piconet, the device that initiates connection becomes the master. Depending on the connection (data, voice, or data and voice) each master in a piconet can manage up to seven slave devices.

If a Bluetooth device listens for other Bluetooth devices broadcasting and doesn't hear anything, it configures itself as a router (master) and broadcasts an "I'm here" signal telling other devices how to connect. If another device comes into range, a PDA for example, and it hears the master device's "I'm here" broadcast, it connects to the master and identifies itself. As other devices come into range they identify themselves to the master and share information about their capabilities and services. If a device with an active Internet connection were to join a piconet, the other devices might take advantage of this capability and check (or send) e-mail.

A Bluetooth device can be a member of multiple piconets at one time, but can only be a master in one. When piconets share one or more devices, they become a scatternet. A maximum of ten fully loaded piconets can be part of a scatternet at any one time.

These devices can connect and disconnect without the user having to lift a finger, or even knowing that it has occurred. You won't have to worry about your PDA talking to every strange Bluetooth device it meets; Bluetooth is safe and devices employ a number of security layers, including an authentification process called pairing, and adequate encryption.

The IEEE licensed a portion of the Bluetooth specification when creating the 802.15.1 standard, creating a standard that is fully compatible with the existing Bluetooth spec giving Bluetooth greater support in the WPAN market. As the Bluetooth SIG further develops the standard, the IEEE will likely incorporate these changes into the 802.15.1 family of standards.

On the web: The Bluetooth Web site provides information about Bluetooth-capable products. For more information, visit www. Bluetooth. com.

Now that you have a good grasp of the key wireless networking standards, you can make informed decisions when you are planning your WLAN and purchasing equipment. However, wireless networking is only half of the wireless story.