One embodiment provides a method for performing a mobility related procedure. The method may comprise: transmitting, by the UE configured with a 2nd/3rd generation mobile communication capability and 4th generation mobile communication capability, a mobility management request message to a first network entity in the 4th generation mobile communication network of a visited public land mobile network (VPLMN); receiving, by the UE and from the first network entity, a mobility management reject message including a rejecting cause value, a first timer and a second timer; if the rejecting cause value indicates that there is no suitable cell in the VPLMN, starting the first timer included in the mobility management reject message; if the first timer is expired, starting the second timer; and until the second timer is expired, disabling the 4th generation communication capability.