One illustrative method of for use in controlling network resources in a wireless network involves assigning, from a pool of IP addresses, a temporary IP address for a mobile station in the wireless network; calculating a ratio or percentage of the number of IP addresses and the total number of IP addresses in the pool; setting a timer value for the mobile station to an initial value that depends on the ratio or percentage of IP addresses such that, as the ratio or percentage increases, the initial value decreases; causing the temporary IP address and the timer value to be sent to the mobile station, which is adapted to register the temporary IP address with a home agent for IP mobility service; and communicating a termination request which terminates the IP mobility service if no request for re-registration is received from the mobile station upon expiration of the timer value.