Method for reducing power consumption of a terminal in cellular system

A method for supporting discontinuous reception operation of a terminal in a base station in wireless communication system, comprising of:

• receiving preferred information for low power-consuming operation from the terminal;
• configuring parameters for performing the discontinuous reception operation of the terminal which is capable of transmitting/receiving data to/from the base station;
• transmitting the configured parameters to the terminal;
• and
• transmitting messages to the terminal,
• wherein the parameters are configured to support discontinuous reception operation by the terminal in an active state,
• wherein the messages are discontinuously monitored according to a discontinuous reception cycle by the terminal,
• wherein uplink synchronization is sustained until a predetermined timer is expired and the uplink synchronization is not sustained after the predetermined timer is expired in the active state being capable of transmitting/receiving data to/from the base station,
• wherein the parameters are configured by the base station based on the preferred information.

A method for discontinuous reception operation of a terminal in wireless communication system, comprising of:

• transmitting preferred information for low power-consuming operation to a base station;
• receiving performing information of whether performing the discontinuous reception operation from the base station;
• and
• performing, in an active state, the discontinuous reception operation based on the performing information,
• wherein messages from the base station are monitored discontinuously according to a discontinuous reception cycle,
• wherein uplink synchronization is sustained until a predetermined time is expired and the uplink synchronization is not sustained after the predetermined time is expired in the active state,
• wherein the performing information is configured by the base station based on the preferred information.

A method for supporting discontinuous reception operation of a terminal in a base station in wireless communication system, comprising of:

• receiving preferred information for low power-consuming operation from the terminal;
• configuring performing information of whether performing the discontinuous reception operation of the terminal which is capable of transmitting/receiving data to/from the base station;
• transmitting the configured performing information to the terminal;
• and
• transmitting messages to the terminal,
• wherein the performing information is configured to support discontinuous reception operation by the terminal in an active state,
• wherein the messages are discontinuously monitored according to a discontinuous reception cycle by the terminal,
• wherein uplink synchronization is sustained until a predetermined timer is expired and the uplink synchronization is not sustained after the predetermined timer is expired in the active state being capable of transmitting/receiving data to/from the base station,
• wherein the performing information is configured by the base station based on the preferred information.

A communication method by a terminal, the method comprising:

• receiving, at the terminal, a first message comprising a first parameter from a base station;
• determining, at the terminal, that a first period of time has passed without receiving a downlink control channel for the terminal from the base station, wherein the first period of time is determined based on the first parameter;
• and
• in response to the determination that the first period of time has passed without receiving the downlink control channel for the terminal from the base station, initiating, at the terminal, a first discontinuous reception (DRX) operation,
• wherein the first DRX operation comprises monitoring the downlink control channel for the terminal during a first duration of time and not monitoring the downlink control channel for the terminal during a second duration of time.

A terminal, comprising:

• a circuitry which is configured to:
• cause the terminal to receive a first message comprising a first parameter from a base station;
• determine that a first period of time has passed without receiving a downlink control channel for the terminal from the base station, wherein the first period of time is determined based on the first parameter;
• and
• cause the terminal to, in response to the determination that the first period of time has passed without receiving the downlink control channel for the terminal from the base station, initiate a first discontinuous reception (DRX) operation,
• wherein the first DRX operation comprises monitoring the downlink control channel for the terminal during a first duration of time and not monitoring the downlink control channel for the terminal during a second duration of time.

A communication device for a terminal, the communication device comprising:

• a circuitry which is configured to:
• cause the terminal to receive a first message comprising a first parameter from a base station;
• determine that a first period of time has passed without receiving a downlink control channel for the terminal from the base station, wherein the first period of time is determined based on the first parameter;
• and
• cause the terminal to, in response to the determination that the first period of time has passed without receiving the downlink control channel for the terminal from the base station, initiate a first discontinuous reception (DRX) operation,
• wherein the first DRX operation comprises monitoring the downlink control channel for the terminal during a first duration of time and not monitoring the downlink control channel for the terminal during a second duration of time.