Bluetooth Technology - Cisco 7925G Administration Manual

Bluetooth Technology

Bluetooth Technology
The Cisco Unified Wireless IP Phones are full-feature telephones and a qualified Bluetooth wireless devices
(Qualified Device ID [QDID] B014396) and provide voice communication over the same wireless LAN that
your computer uses. In addition to basic call-handling features, your phone operates with Bluetooth wireless
headsets, including certain hands-free call features.
Bluetooth devices operate in the unlicensed Industrial Scientific Medicine (ISM) band of 2.4 GHz, which is
the same as the 802.11b/g band. This unlicensed band in most countries includes the frequency range from
2400 to 2483.5 MHz. Bluetooth enables low bandwidth wireless connections within a range of 10 meters.
The best performance is in the 1 to 2 meter range. Synchronous voice channels are provided by using circuit
switching and asynchronous data channels are provided by using packet switching.
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 1: Bluetooth Maximum Permitted Transmit Power and Range by Class
Class
Class 1
Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Administration Guide
10
Maximum permitted transmit power (mW, dBm)
100 mW, 20 dBm
Cisco Unified Wireless IP Phone
Range
Up to 100 meters