Patent ID: 10136352

Abstract:
Provided is a method of sending and receiving signals for a user equipment (UE) in a mobile communication system. The method may include: receiving a service reject message from a Mobility Management Entity (MME) under congestion; sending a message containing at least one piece of information determined based on the service reject message to a Mobile Switching Center (MSC); receiving a message containing camping cell information from a base station (eNB); and camping on a cell indicated by the camping cell information. In one embodiment, when an MM back-off timer is applied to the UE utilizing CSFB (or SMS over SGs) at the time of network congestion, the MSC or 2G/3G RAN node is notified that the MM back-off timer is running in the UE, so that the UE may camp not on an LTE cell but on a 2G/3G cell after CS service reception. Hence, it is possible to prevent call drops for MT services that may be caused by UE location registration failure due to the MM back-off timer.