Method for keeping mobile initiated connection only mode user equipment in connected mode

A method performed by an access and mobility management function (AMF) in a communication system, the method comprising:

• transmitting, to a base station, a message including first information indicating that a mobile initiated communication only (MICO) mode is allowed for a terminal and second information on a time value for maintaining the terminal in a radio resource control (RRC) connected state;
• receiving, from the base station, a request message for releasing an N2 connection between the AMF and the base station after a timer according to the time value is expired, in case that the time value is larger than a value of an RRC inactive timer;
• and
• receiving, from the base station, the request message for releasing the N2 connection after the timer according to the value of the RRC inactive timer is expired, in case that the time value is not larger than the value of the RRC inactive timer,
• wherein the RRC inactive timer is used for determining an RRC connection inactivity of the terminal.

A base station in a communication system, the base station comprising:

• a transceiver;
• and
• a controller configured to:
• receive, from an access and mobility management function (AMF), a message including first information indicating that a mobile initiated communication only (MICO) mode is allowed for a terminal and second information on a time value for maintaining the terminal in a radio resource control (RRC) connected state,
• in case that the time value is larger than a value of an RRC inactive timer, determine to release an N2 connection between the base station and the AMF after a timer according to the time value is expired, and transmit, to the AMF, a request message for releasing the N2 connection, and
• in case that the time value is not larger than the value of the RRC inactive timer, determine to release the N2 connection between the base station and the AMF after the timer according to the value of the RRC inactivity inactive timer is expired, and transmit, to the AMF, the request message for releasing the N2 connection,
• wherein the RRC inactive timer is used for determining an RRC connection inactivity of the terminal.

An access and mobility management function (AMF) in a communication system, the AMF comprising:

• a transceiver;
• and
• a controller configured to:
• transmit, to a base station, a message including first information indicating that a mobile initiated communication only (MICO) mode is allowed for a terminal and second information on a time value for a maintaining the terminal in a radio resource control (RRC) connected state,
• control the transceiver to receive, from the base station, a request message for releasing an N2 connection between the AMF and the base station after a timer according to the time value is expired, in case that the time value is larger than a value of an RRC inactive timer, and
• control the transceiver to receive, from the base station, the request message for releasing the N2 connection after the timer according to the value of the RRC inactive timer is expired, in case that the time value is not larger than to the value of the RRC inactive timer,
• wherein the RRC inactive timer is used for determining an RRC connection inactivity of the terminal.