Method, system, and device for providing service

A system for providing a service, comprising:

• a delivery device, configured to deliver a network instruction to user equipment (UE);
• the UE, configured to initiate a call to a device for providing a service in a Circuit Switched (CS) domain after acquiring the network instruction delivered by the delivery device;
• and
• a device for providing a service, configured to provide the service after receiving the call from the UE.

A user equipment (UE), comprising:

• an acquisition module, configured to acquire a network instruction;
• and
• a processing module, configured to initiate a call in a circuit switched (CS) domain after the acquisition module acquires the network instruction;
• wherein
• the acquisition module is configured to send a session request message carrying a number and an identifier to a Proxy Call Session Control Function (P-CSCF), and acquire an instruction to not establish a session by using an ICCP signaling sent by the P-CSCF;
• and
• the processing module is configured to initiate an emergency call in the CS domain after the acquisition module acquires the instruction;

A user equipment (UE), comprising:

• an acquisition module, configured to acquire a network instruction;
• and
• a processing module, configured to initiate a call in a circuit switched (CS) domain after the acquisition module acquires the network instruction;
• wherein
• the acquisition module is configured to send a session request message carrying a number and an identifier to a P-CSC, and acquire a notification that the session is an emergency call sent by the P-CSCF;
• and
• the processing module is configured to determine not to establish a session by using an ICCP signaling and initiate an emergency call in the CS domain after the acquisition module acquires the notification.

A user equipment (UE), comprising:

• an acquisition module, configured to acquire a network instruction;
• and
• a processing module, configured to initiate a call in a circuit switched (CS) domain after the acquisition module acquires the network instruction;
• wherein
• the acquisition module is configured to send a session request message carrying user data and an identifier to a P-CSCF, and acquire an instruction of not establishing a session by using an ICCP signaling sent by the P-CSCF, wherein the user data comprises one or more of:
• a called number, a calling number, a terminal identifier, and location information;
• and
• the processing module is configured to initiate a call in the CS domain after the acquisition module acquires the instruction.