Call Processing Method, Call Server, Base Station, and Call System

A call processing method, comprising:

• receiving, by a base station, a paging message from a mobility management entity instructing to page a called terminal;
• paging, by the base station, the called terminal according to the paging message;
• sending, by the base station to the mobility management entity, a paging response message indicating that the called terminal is in a power saving state and cannot be paged by the base station when the called terminal is in the power saving state and cannot be paged by the base station;
• continuously paging, by the base station, the called terminal;
• and
• triggering, by the base station, the mobility management entity to send addressing information of the called terminal to a call server when it is determined, in a continuous paging process, the called terminal is woken up from the power saving state, the addressing information of the called terminal indicating that the called terminal is woken up from the power saving state and is paged by the base station.

A call server, comprising:

• a receiver configured to receive a first call request of a calling terminal for a called terminal;
• a non-transitory computer-readable storage medium coupled to the receiver and configured to store programming instructions;
• and
• at least one processor coupled to the receiver and the non-transitory computer-readable storage medium, the programming instructions causing the at least one processor to be configured to:
• trigger according to the first call request, a mobility management entity to control a base station to page the called terminal;
• perform call waiting according to a paging response message when the paging response message from the mobility management entity indicating that the called terminal is in a power saving state and cannot be paged by the base station is received;
• and
• establish a session coupling between the calling terminal and the called terminal according to addressing information of the called terminal when the addressing information of the called terminal from the mobility management entity is received in a call waiting process, the addressing information of the called terminal indicating that the called terminal is woken up from the power saving state and is paged by the base station.

A base station, comprising:

• a receiver configured to receive a paging message from a mobility management entity instructing to page a called terminal;
• a non-transitory computer-readable storage medium coupled to the receiver and configured to store programming instructions;
• at least one processor coupled to the receiver and the non-transitory computer-readable storage medium, the programming instructions causing the at least one processor to be configured to page the called terminal according to the paging message;
• and
• a transmitter coupled to the at least one processor and configured to send a paging response message indicating that the called terminal is in a power saving state and cannot be paged by the base station to the mobility management entity when the called terminal is in the power saving state and cannot be paged by the base station, and
• the programming instructions further causing the at least one processor to be configured to:
• continuously page the called terminal;
• trigger the mobility management entity to send addressing information of the called terminal to a call server when it is determined, in a continuous paging process, that the called terminal is woken up from the power saving state, the addressing information of the called terminal indicating that the called terminal is woken up from the power saving state and is paged by the base station.