Performing a Site Survey Verification
Requirements for an Optimal Wireless Voice Environment
Note
Cisco Wireless IP Phone 7920 Administration Guide for Cisco CallManager Release 3.3 or Later
6-18
Chapter 6
Configuring the Wireless Network Settings on the Cisco Wireless IP Phone 7920
When you perform a post-installation site survey, use the following guidelines to
verify that you have adequate access point coverage for roaming Cisco Wireless
IP Phones. These guidelines will help you have a successful voice deployment in
your wireless environment.
For more detailed information about the wireless voice requirements, refer to the
Cisco Wireless IP Phone 7920 Design and Deployment Guide
•
Minimum of two access points on non-overlapping channels appear in the
7920 Site Survey utility at all times.
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No more than one AP per overlapping channel with a radio signal strength
indicator (RSSI) less than 35.
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Two of the APs, including the connected (C) AP must have an RSSI of greater
than 35. Two APs insure that phones can roam easily and that a backup AP is
available when one AP is busy or unavailable.
The available link speed must be at 11 Mbps at all times.
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AP coverage should overlap by 20 percent.
The packet error rate (PER) should be no higher than one percent.
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The minimum signal to noise ratio (SNR) should be 25 db.
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The transmit power should be the same for both the AP and phones.
All APs must have diversity antennas and must use the diversity setting.
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In a high traffic area such as a conference room, use additional APs to balance
the load.
Related Topics
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Site Survey Verification Steps, page 6-15
Overview of a Wireless LAN, page 1-4
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Interacting with the Cisco Aironet Access Point, page 2-2
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Voice Quality in a Wireless Network, page 2-5
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