Planet WNL-9331 User Manual page 32

After you finish the settings, click 'Apply' to apply new settings, and click 'OK' to close
configuration utility.
Turn on CCKM: Check this box to enable CCKM (Cisco
Centralized Key Management), which enables wireless clients to
roam between CCKM-enabled access points in very short time.
Enable Radio Measurements: When you're connecting to
CCX-compatible access point, check this box to enable radio
measurement function to improve wireless connectivity.
Non-Serving Channel Measurements Limit: When you're
connecting to CCX-compatible access point, check this box to
enable measurement on unused radio channels to improve
wireless connectivity.