Chapter 3 Using Bluetooth; Introduction; Adaptive Frequency Hopping - Motorola MC7090CN User Manual

Chapter 3
Chapter 3
Using Bluetooth

Introduction

Bluetooth-equipped devices can communicate without wires, using frequency-hopping spread spectrum
(FHSS) radio frequency (RF) to transmit and receive data in the 2.4 GHz Industry Scientific and Medical (ISM)
band (802.15.1). Bluetooth wireless technology is specifically designed for short-range (30 feet/10 meters)
communication and low power consumption.
EDAs with Bluetooth capabilities can exchange information (e.g., files, appointments, and tasks) with other
Bluetooth enabled devices such as phones, printers, access points, and other mobile computers. To use the
Bluetooth phone as a modem, create a dial-up modem connection between the Bluetooth mobile computer
and a Bluetooth enabled phone.
Zebra mobile computers with Bluetooth technology use the StoneStreet Bluetooth stack. To program Bluetooth
within the EDA refer to the Microsoft Embedded Visual C++ help.

Adaptive Frequency Hopping

Adaptive Frequency Hopping (AFH) is a method of avoiding fixed frequency interferers. All devices in the
piconet (Bluetooth network) must be AFH-capable in order for AFH to work. There is no AFH when connecting
and discovering devices. Avoid making Bluetooth 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 channel-by-channel basis, or
•
pre-defined channel mask.
Link Management - Coordinates and distributes the AFH information to the rest of the Bluetooth network.
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Hop Sequence Modification - Avoids interference by selectively reducing the number of hopping
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channels.
Channel Maintenance - A method for periodically re-evaluating the channels.
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When AFH is enabled, the Bluetooth radio "hops around" (instead of through) the 802.11b high-rate channels.
AFH coexistence allows Zebra mobile computers to operate in any infrastructure.
The Bluetooth radio in this EDA operates as a Class 2 device power class. The maximum output power is
2.5mW and the expected range is 32.8 feet (10 meters). A definition of ranges based on power class is difficult
to obtain due to power and device differences, and whether one measures open space or closed office space.
It is not recommended to perform Bluetooth wireless technology inquiry when high rate
NOTE
802.11b operation is required.
Using Bluetooth