Chapter 4 Using Bluetooth
Introduction
Bluetooth-equipped devices can communicate without wires, using frequenc y-hopping spread spectrum (FHSS)
radio frequency (RF) to transmit and receive data in the 2.4 GHz Industr y Scientific and Medical (ISM) band
(802.15.1). Bluetooth wireless technology is specifically designed for shor t-range (30 feet/10 meters)
communication and low power consumption.
MC75s with Bluetooth capabilities can exchange information (e.g., files, appointm ents, and tasks) with other
Bluetooth enabled devices such as phones, printers, access points, and other mobil e computers. To use the MC75
as a modem, create a dial-up modem connection between a computer and MC75.
Motorola mobile computers with Bluetooth technology use the StoneStreet Bluetooth stack. To program Bluetooth
within the MC75 refer to the Enterprise Mobility Developer Kit (EMDK) Help.

Adaptive Frequency Hopping

Adaptive Frequency Hopping (AFH) is a method of avoiding fixed frequency in terferers, and can be used with
Bluetooth voice. All devices in the piconet (Bluetooth network) must be A FH-capable in order for AFH to work.
There is no AFH when connecting and discovering devices. Avoid making Blue tooth connections and discoveries
during critical 802.11b communications. AFH for Bluetooth consists of four main sections:
•
Channel Classification - A method of detecting an interference on a chan nel-by-channel basis, or pre-defined
channel mask.
•
Link Management - Coordinates and distributes the AFH information to the rest of the Bluetooth network.
•
Hop Sequence Modification - Avoids interference by selectively reduc ing the number of hopping channels.
•
Channel Maintenance - A method for periodically re-evaluating the chan nels.
When AFH is enabled, the Bluetooth radio “hops around” (instead o f through) the 802.11b high-rate channels. AFH
coexistence allows Motorola mobile computers to operate in any infrastr ucture.