A method of handling a communication session, comprising: at a wireless mobile communications device: receiving an indication of current signal strength of an access point for a wireless local area network, WLAN; retrieving a signal strength threshold associated with said access point; if said communication session is currently carried by said WLAN and said current signal strength is below said signal strength threshold, attempting to switch said communication session from said WLAN to a cellular network; adjusting a failure rate associated with said access point based on whether said attempting to switch said communication session from said WLAN to said cellular network failed; where said attempting to switch results in a switch, adjusting a switch rate associated with said access point so that said switch rate reflects the number of switches per minute of said communication session from said WLAN to said cellular network and the number of such switches per minute of previous communication sessions over a preceding time window; and based on said failure rate and said switch rate (H4, Table 9), selectively adjusting said signal strength threshold associated with said access point. at a wireless mobile communications device: receiving an indication of current signal strength of an access point for a wireless local area network, WLAN; retrieving a signal strength threshold associated with said access point; if said communication session is currently carried by said WLAN and said current signal strength is below said signal strength threshold, attempting to switch said communication session from said WLAN to a cellular network; adjusting a failure rate associated with said access point based on whether said attempting to switch said communication session from said WLAN to said cellular network failed; where said attempting to switch results in a switch, adjusting a switch rate associated with said access point so that said switch rate reflects the number of switches per minute of said communication session from said WLAN to said cellular network and the number of such switches per minute of previous communication sessions over a preceding time window; and based on said failure rate and said switch rate (H4, Table 9), selectively adjusting said signal strength threshold associated with said access point. receiving an indication of current signal strength of an access point for a wireless local area network, WLAN; retrieving a signal strength threshold associated with said access point; if said communication session is currently carried by said WLAN and said current signal strength is below said signal strength threshold, attempting to switch said communication session from said WLAN to a cellular network; adjusting a failure rate associated with said access point based on whether said attempting to switch said communication session from said WLAN to said cellular network failed; where said attempting to switch results in a switch, adjusting a switch rate associated with said access point so that said switch rate reflects the number of switches per minute of said communication session from said WLAN to said cellular network and the number of such switches per minute of previous communication sessions over a preceding time window; and based on said failure rate and said switch rate (H4, Table 9), selectively adjusting said signal strength threshold associated with said access point.