Enabling circuit-switched services during mobility management congestion control

Abstract

A method is provided that includes causing transmission of a first mobility management (MM) message from a UE to a core network including packet-switched (PS) and circuit-switched (CS) domains. The method may include causing transmission of the first MM message to a PS-domain component, and receiving a rejection message from the PS-domain component in response thereto. The rejection message indicates congestion as a cause for rejection of the first MM message, and indicates whether circuit-switched services are permitted or forbidden during running of the back-off timer. In response to receipt of the rejection message, the method may include running a back-off timer. While the back-off timer is running in an instance in which the rejection message indicates that circuit-switched services are permitted, the method may include causing transmission of a second MM message from the UE to a CS-domain component. A corresponding apparatus and computer-readable storage medium are also provided.

1 . An apparatus comprising:
 at least one processor; and   at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least:   cause transmission of a first mobility management message from user equipment to a core network including a packet-switched domain and a circuit-switched domain, the apparatus being caused to cause transmission of the first mobility management message including being caused to cause transmission of the first mobility management message to a component of the packet-switched domain;   receive a rejection message at the user equipment from the packet-switched domain component in response to the first mobility management message, the rejection message indicating congestion as a cause for rejection of the first mobility management message, and indicating whether circuit-switched services are permitted or forbidden during running of the back-off timer; and   run a back-off timer in response to receipt of the rejection message, the back-off timer indicating a time during which the user equipment defers transmission of any further mobility management messages to the packet-switched domain component,   wherein the indication in the rejection message that circuit-switched services are permitted enables the apparatus to cause transmission of a second mobility management message from the user equipment to a component of the circuit-switched domain, while the back-off timer is running.   
     
     
         2 . The apparatus of  claim 1 , wherein the apparatus being caused to receive the rejection message includes being caused to receive the rejection message including a value of the back-off timer, and
 wherein the apparatus being caused to run the back-off timer includes being caused to run the back-off timer starting with the value.   
     
     
         3 . The apparatus of  claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to further:
 cause transmission of the second mobility management message from the user equipment to the component of the circuit-switched domain, the apparatus being caused to cause transmission of the second mobility management message in an instance in which the rejection message indicates that circuit-switched services are permitted, and while the back-off timer is running.   
     
     
         4 . The apparatus of  claim 3 , wherein the apparatus being caused to cause transmission of the first mobility management message includes being caused to cause transmission of a request to attach to the packet-switched domain, perform a routing area update or receive a packet-switched service. 
     
     
         5 . The apparatus of  claim 1 , wherein the at least one processor and at least one memory are components of a mobile phone, and one or more of the at least one processor is directly or indirectly connected to one or more other components of the mobile phone. 
     
     
         6 . The apparatus of  claim 5 , wherein the one or more other components of the mobile phone include:
 user interface circuitry; and   user interface software configured to facilitate user control of at least some functions of the mobile phone through use of a display.   
     
     
         7 . An apparatus comprising:
 at least one processor; and   at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least:   receive a first mobility management message at a core network from user equipment, the core network including a packet-switched domain and a circuit-switched domain, the first mobility management message being received at a component of the packet-switched domain;   detect congestion in the core network; and in response thereto,   cause transmission of a rejection message from the packet-switched domain component to the user equipment in response to receipt of the first mobility management message, the rejection message indicating congestion as a cause for rejection of the first mobility management message,   wherein receipt of the rejection message at the user equipment causes the user equipment to run a back-off timer indicating a time during which the user equipment defers transmission of any further mobility management messages to the packet-switched domain component,   wherein the rejection message further indicates whether circuit-switched services are permitted or forbidden during running of the back-off timer, and   wherein in an instance in which the rejection message indicates that circuit-switched services are permitted, receipt of the rejection message at the user equipment enables the user equipment to transmit a second mobility management message from the user equipment to a component of the circuit-switched domain while the back-off timer is running.   
     
     
         8 . The apparatus of  claim 7 , wherein the apparatus being caused to cause transmission of the rejection message includes being caused to cause transmission of the rejection message including a value of the back-off timer, and wherein receipt of the rejection message at the user equipment causes the user equipment to run the back-off timer starting with the value. 
     
     
         9 . The apparatus of  claim 7 , wherein the apparatus being caused to receive the first mobility management message includes being caused to receive a request to attach to the packet-switched domain, perform a routing area update or receive a packet-switched service. 
     
     
         10 . A method comprising:
 causing transmission of a first mobility management message from user equipment to a core network including a packet-switched domain and a circuit-switched domain, causing transmission of the first mobility management message includes causing transmission of the first mobility management message to a component of the packet-switched domain;   receiving a rejection message at the user equipment from the packet-switched domain component in response to the first mobility management message, the rejection message indicating congestion as a cause for rejection of the first mobility management message, and indicating whether circuit-switched services are permitted or forbidden during running of the back-off timer; and   running a back-off timer in response to receipt of the rejection message, the back-off timer indicating a time during which the user equipment defers transmission of any further mobility management messages to the packet-switched domain component,   wherein the indication in the rejection message that circuit-switched services are permitted enables the apparatus to cause transmission of a second mobility management message from the user equipment to a component of the circuit-switched domain, while the back-off timer is running,   wherein causing transmission of the first mobility management message, receiving the rejection message and running the back-off timer are performed by an apparatus including a processor and memory including computer program code, the memory and computer program code being configured to, with the processor, cause the apparatus at least cause transmission of the first mobility management message, receive the rejection message and run the back-off timer.   
     
     
         11 . The method of  claim 10 , wherein receiving the rejection message includes receiving the rejection message including a value of the back-off timer, and
 wherein running the back-off timer includes running the back-off timer starting with the value.   
     
     
         12 . The method of  claim 10  further comprising:
 causing transmission of the second mobility management message from the user equipment to the component of the circuit-switched domain, transmission of the second mobility management message being caused in an instance in which the rejection message indicates that circuit-switched services are permitted, and while the back-off timer is running. 
 
     
     
         13 . The method of  claim 12 , wherein causing transmission of the first mobility management message includes causing transmission of a request to attach to the packet-switched domain, perform a routing area update or receive a packet-switched service. 
     
     
         14 . A method comprising:
 receiving a first mobility management message at a core network from user equipment, the core network including a packet-switched domain and a circuit-switched domain, the first mobility management message being received at a component of the packet-switched domain;   detecting congestion in the core network; and in response thereto,   causing transmission of a rejection message from the packet-switched domain component to the user equipment in response to receipt of the first mobility management message, the rejection message indicating congestion as a cause for rejection of the first mobility management message,   wherein receipt of the rejection message at the user equipment causes the user equipment to run a back-off timer indicating a time during which the user equipment defers transmission of any further mobility management messages to the packet-switched domain component,   wherein the rejection message further indicates whether circuit-switched services are permitted or forbidden during running of the back-off timer,   wherein in an instance in which the rejection message indicates that circuit-switched services are permitted, receipt of the rejection message at the user equipment enables the user equipment to transmit a second mobility management message from the user equipment to a component of the circuit-switched domain while the back-off timer is running, and   wherein receiving the first mobility management message, detecting congestion in the core network and causing transmission of the rejection message are performed by an apparatus including a processor and memory including computer program code, the memory and computer program code being configured to, with the processor, cause the apparatus at least receive the first mobility management message, detect congestion in the core network and cause transmission of the rejection message.   
     
     
         15 . The method of  claim 14 , wherein causing transmission of the rejection message includes causing transmission of the rejection message including a value of the back-off timer, and wherein receipt of the rejection message at the user equipment causes the user equipment to run the back-off timer starting with the value. 
     
     
         16 . The method of  claim 14 , wherein receiving the first mobility management message includes receiving a request to attach to the packet-switched domain, perform a routing area update or receive a packet-switched service.