Cisco Unified Wireless IP Phone 7925G Series Deployment Guide
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The number of calls may vary depending on the data rate, initial channel utilization, and the environment.
Max # of Streams
802.11 Mode
Data Rate
13
802.11a or 802.11g + Bluetooth Disabled
6 Mbps
20
802.11a or 802.11g + Bluetooth Disabled
12 Mbps
27
802.11a or 802.11g + Bluetooth Disabled
24 – 54 Mbps
When using Coexistence (802.11b/g + Bluetooth), call capacity is reduced to the following:
Max # of Streams
802.11 Mode
Data Rate
4
802.11b/g + Bluetooth Enabled
11, <12-54> Mbps
7
802.11g + Bluetooth Enabled
12, <18-54> Mbps
Note:
It is highly recommended to use 802.11a if using Bluetooth.
Prior to release 1.3(3), only 2 bi-directional RTP streams were supported when using Coexistence.
Dynamic Transmit Power Control (DTPC)
To successfully exchange packets between the wireless IP phone and the access point, Dynamic Transmit Power Control
(DTPC) should be enabled.
When using an access point that supports DTPC, set the client power to match the local access point power.
Do not use default setting of Max power for client power on Cisco autonomous access points as that will not advertise DTPC to
the client.
If the access point does not support DTPC, then the Cisco Unified Wireless IP Phone 7925G Series will use the highest
available transmit power depending on the current 802.11 mode and data rate.
The transmit power on the Cisco Unified Wireless IP Phone 7925G Series can also optionally be configured to match the
highest transmit power of an access point in the wireless LAN. This setting prevents one-way audio when RF traffic is heard in
one direction only.
By default the Cisco Unified Wireless IP Phone 7925G Series will use the highest available transmit power by default (i.e. 17
dBm / 50 mW for 2.4 GHz and 16 dBm / 40 mW for 5 GHz).
The access point’s radio transmit power should not have a transmit power greater than what the Cisco Unified Wireless IP
Phone 7925G Series can support.
