CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

2.3. Other Wireless

Two more products fall into the wireless networking category: Bluetooth and cellular. Bluetooth is used as a communication link between different devices, and cellular is used for remote dialup networking or Internet access. In both cases, using these wireless devices is very different than the 802.11 wireless networking protocols, which are designed to be a short-range extension of a LAN (local area network).

2.3.1. Bluetooth

Bluetooth follows the standards set out in the IEEE 802.15.1 specification. As a personal area network (PAN), Bluetooth is designed primarily for use in very small areas or short ranges, such as on a person's body. You have probably seen cordless cellular phone headsets, which operate over the space between the headset in the ear and a phone carried on the hip or in a purse. Most wireless links for today's cell phones and PDAs use Bluetooth. You might not immediately think of these links as being on a network — after all, you are not surfing the Internet or transferring files — but you are transferring data, in some form, between the devices. There are three classes of devices on Bluetooth networks:

• Class 1 devices operate at 100 milliwatt (mW) and have a range of 100 meters.

• Class 2 devices operate at 2.5 mW and have a range of 10 meters.

• Class 3 devices operate at 1 mW and have a range of about 1 meter.

  NOTE

  Most devices are Class 3. Class 3 Bluetooth devices include telephone and computer headsets, PDA-to-PC synchronization, printers, ...