Automatic Wireless Configuration

Some WLAN controllers offer automatic configuration features that allow you to dynamically adjust transmit power levels and wireless channels used by the access points.

To tune the configuration for your Vocera system consider the following:

Dynamic Transmit Power Adjustment—If an access point goes offline, its neighboring access points will increase their power to compensate for the coverage hole. If not tuned properly for Vocera, the Dynamic Transmit Power Adjustment feature can cause neighboring APs to increase their power, resulting in transmit power asymmetry in some coverage areas, which in turn may cause choppy audio or one-way audio on badge calls.

Vocera suggests limiting the Dynamic Transmit Power adjustment according to the device and frequency as shown in the following:

Device and Frequency	Maximum Adjustment
B3000n Transmit Power 5GHz	Max 16dBm (40mW) - Min 13dBm (20mW)
B3000n Transmit Power 2.4 GHz	Max 17dBm (50mW) - Min 12dBm (16mW)
B3000 Transmit Power only in 2.4 GHz	Max 15dBm (30mW) - Min 11dBm (12.5mW)

Dynamic Channel Assignment—If the adaptive wireless network detects an interference that conflicts with the channel of the access point, it may change the channel of some or all of the access points on the network. There is no mechanism for the access point to inform the badge that it is changing its channel. When the access point changes its channel, the badge may take several seconds to discover that the access point it is associated with is no longer on that channel and it will begin its roaming process to find a suitable access point.

For more information on tuning Radio Resource Management (RRM) algorithms for Cisco CAPWAP deployments, refer to Best Practices for Cisco Unified Wireless Networks (CAPWAP).

If you decide to use automatic AP configuration features, it is important that you perform a complete voice quality site survey after the configuration. You may need to tune the settings. Resurvey the system to verify proper coverage and power levels.