WS501 Product Reference Guide for Android™ 14

Adaptive Frequency Hopping

Adaptive Frequency Hopping (AFH) is a method of avoiding fixed frequency interferers, and can be used with Bluetooth voice. 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.

Hop Sequence Modification - Avoids interference by selectively reducing the number of hopping channels.

Channel Maintenance - A method for periodically re-evaluating the channels.

When AFH is enabled, the Bluetooth radio “hops around” (instead of through) the 802.11b high-rate channels. AFH coexistence allows enterprise devices to operate in any infrastructure.

The Bluetooth radio in this device operates as a Class 1 device power class. The maximum output power is

5

mW and the expected range is 20 m (65.5 ft). A definition of ranges based on power class is difficult to obtain due to power and device differences, and whether in open space or closed office space.

It is not recommended to perform Bluetooth wireless technology inquiry when high rate 802.11b operation is required.