Cisco 8821

Bluetooth uses integrated Adaptive Frequency Hopping (AFH) to avoid interference. Every 625 microseconds
(1/1,000,000 of a second) the channel changes or hops to another frequency within the 2402 to 2480 MHz
range. This equals 1600 hops every second.
The phones contain a Bluetooth module and 802.11 WLAN module. This coexistence greatly reduces and
avoids radio interference between the Bluetooth and 802.11b/g radio.
Bluetooth devices fit into to three different power classes, as shown in the following table.
Table 21: Bluetooth Maximum Permitted Transmit Power and Range by Class
RangeMaximum permitted transmit power (mW, dBm)Class
Up to 100 meters100 mW, 20 dBmClass 1
Up to 10 meters2.5 mW, 4 dBmClass 2
Up to 1 meter1 mW, 0 dBmClass 3
Bluetooth Class 2.0 with Extended Data Rate (EDR) is a short-range wireless technology that is supported
by the wireless IP phones. The phones support the Hands-Free Profile Version 1.5.
Because of potential interference issues, we recommend that you:
•
Use 802.11a that operates in the 5 GHz band.
•
Reduce the proximity of other 802.11b/g devices, Bluetooth devices, microwave ovens, and large metal
objects.
•
Use the phone on the same side of the body as the Bluetooth-enabled headset.
The Cisco Wireless IP Phone 8821-EX has not been tested or certified to use any Bluetooth accessories
in hazardous environments.
Caution
For information about pairing headsets, see Headset Usage, on page 135.
For more information about Bluetooth and hands-free profiles, see http://www.bluetooth.com.
Headset Usage
Although Cisco performs some internal testing of third-party wired and Bluetooth wireless headsets for use
with the wireless phone, Cisco does not certify or support products from headset or handset vendors. Because
of the inherent environmental and hardware inconsistencies in the locations where phones are deployed, there
is not a single “best” solution that is optimal for all environments. Cisco recommends that customers test the
headsets that work best in their environment before deploying a large number of units in their network.
The Cisco Wireless IP Phone 8821-EX has not been tested or certified to use any Bluetooth accessories,
including headsets, in hazardous environments.
Caution
Cisco Wireless IP Phone 8821 and 8821-EX Administration Guide for Cisco Unified Communications Manager
135
Technical Specifications
Headset Usage