The Cisco Unified WCS or NCS can be utilized to verify signal strength and coverage.
Configuring Data Rates
It is recommended to disable rates below 12 Mbps for 802.11a and below 11 Mbps for 802.11b/g deployments where capacity
and range are factored in for best results.
Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Deployment Guide
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