Method and system for optimizing ims pdn connection in communication system

A method for optimizing an internet protocol (IP) multimedia subsystem (IMS) packet data network (PDN) connection, the method comprising:

• receiving, by at least one data network element of a communication network from a user equipment, a request for establishing an IMS PDN connection and an internet PDN connection;
• allocating, by the at least one data network element to a user equipment (UE), a primary IP address corresponding to the IMS PDN connection and a secondary IP address corresponding to the internet PDN connection;
• receiving, by an IMS from the UE, information on the secondary IP address over the internet PDN connection, before disconnecting the IMS PDN connection by the communication network;
• and
• while the IMS PDN connection is disconnected, transmitting, by the IMS to the UE, a mobile terminated (MT) call notification using the secondary IP address, over the internet PDN connection after detecting a MT call directed to the UE, wherein the IMS PDN connection is established by the UE, based on the MT call notification.

A user equipment (UE) for optimizing an internet protocol (IP) multimedia subsystem (IMS) packet data network (PDN) connection, the UE comprising:

• at least one processor comprising processing circuitry;
• and
• memory including one or more storage mediums storing instructions,
• wherein the instructions that, when executed by the at least one processor individually or collectively, cause the UE to:
• establish an IMS PDN connection and an internet PDN connection with at least one data network element of a communication network, wherein a primary IP address corresponding to the IMS PDN connection and a secondary IP address corresponding to the internet PDN connection are allocated to the UE by the at least one data network element;
• transmit to an IMS, information on the secondary IP address over the internet PDN connection before the IMS PDN connection is disconnected by the communication network;
• receive from the IMS, a mobile terminated (MT) call notification using the secondary IP address over the internet PDN connection while the IMS PDN connection is disconnected;
• and
• establish the IMS PDN connection based on the MT call notification.

An internet protocol (IP) multimedia subsystem (IMS) for optimizing IMS packet data network (PDN) connection, wherein the IMS comprising:

• at least one processor comprising processing circuitry;
• and
• memory including one or more storage mediums storing instructions,
• wherein the instructions that, when executed by the at least one processor individually or collectively, cause the IMS to:
• receive, from a user equipment (UE), information on a secondary IP address among a primary IP address corresponding to an IMS PDN connection with the UE and the secondary IP address corresponding to an internet PDN connection with the UE, over the internet PDN connection before the IMS PDN connection is disconnected by at least one data network element, wherein the primary IP address and the secondary IP address are allocated by the by at least one data network element;
• transmit, to the UE, a mobile terminated (MT) call notification using the secondary IP address, over the internet PDN connection after detecting a MT call directed to the UE while the IMS PDN connection is disconnected;
• and
• establish the IMS PDN connection based on the MT call notification.