A method and a user equipment (UE) are described for controlling timers in a wireless communication system including a first type network communicating based on a number of orthogonal frequency-division multiplexing (OFDM) symbols and a second type network which is different from the first type network. An update message is received that activates an idle mode signaling reduction (ISR) function of the UE. If the ISR function is activated in the UE, a periodic tracking area updating (P-TAU) timer is started, which is used to periodically notify availability of the UE. If the P-TAU timer expires and a mobility management backoff (MM-BO) timer is running, a deactivate ISR timer corresponding to the first type of network is started. The MM-BO timer is configured to start when a MM-BO time value is received at the UE.