After review of the document the only settings I wa able to change was the DTIM Period from 1 to 2 and the tx rate for 5Ghz to 18 - 24. Did not have any other options for the other settings when it came to the radio profile. The settings in red below was what I was able to change on the AP105 model, I attached the screen shot below. I was not even able to enter them at the terminal session for the voice profile. After the two settings I put the 7921g phones on Auto 802.11a and restart. They seem to connect faster and they did not drop the call with roaming. I will continue to monitor until maybe you guys review and see somthing i'm missing.
Like:
wlan ssid-profile "<792X SSID profile name>" essid "<792X SSID name>" opmode wpa2-aes dtim-period 2 a-basic-rates 6 12 24 a-tx-rates 6 9 12 18 24 max-retries 3 max-tx-fail 25 disable-probe-retry wmm deny-bcast ! rf dot11a-radio-profile "<802.11a radio profile name>" arm-profile "<802.11a arm profile name>" ! rf arm-profile "802.11a arm profile name>" max-tx-power 18 min-tx-power 12 voip-aware-scan ! rf ht-radio-profile <802.11a