Abstract: Proposed is a federated learning system. The federated learning system comprises: a central server configured to transmit at least one global parameter of a global model to each client device, receive at least one local parameter of a local model trained from each of client devices, and update the global model using the at least one local parameter; and a plurality of client devices configured to train the local model by applying a loss between a predicted value of the global model and a predicted value of the local model possessed by itself to a loss function, and transmit at least one local parameter of the trained local model to the central server.

Abstract: Proposed is a federated learning system. The federated learning system may comprise: a central server configured to transmit a first parameter of an extractor in a federated learning model including the extractor and a classifier to each of a plurality of client devices, and receive a plurality of first parameters learned from the plurality of client devices to update the federated learning model; and the plurality of client devices configured to train each of the plurality of the first parameters of the federated learning model using a training data set stored in each of the plurality of client devices while maintaining a value of a second parameter value of the classifier in the federated learning model, and to transmit each of the plurality of the trained first parameters to the central server.

Abstract: Disclosed is a method and system for transmitting and receiving data in a communication system. The system includes a base station, and a relay station connecting the base station with at least one mobile station. The base station transmits data for a plurality of mobile stations to the relay station, and transmits the data to at least one mobile station belonging to the base station from among the plurality of mobile stations. The relay station receives the data from the base station, and transmits the data to at least one mobile station belonging to the relay station from among the plurality of mobile stations in the same interval as an interval where the base station transmits the data to the mobile station.

Abstract: An apparatus and method for transmitting/receiving a Channel Quality Information (CQI) in a communication system are provided. A Mobile Station (MS) receives first information indicating a representative MS selected from a group of MSs located within a preset range and in similar channel statuses, the group including the MS, determines from the first information whether the MS is designated as the representative MS, and transmits a CQI of the MS as a representative CQI of the MSs included in the group to a Base Station (BS), if the MS is designated as the representative MS.

Abstract: Disclosed is a system and method for transmitting data based on an operational state of a mobile station in a communication system. The method includes, when detecting a low battery state of the mobile station, storing one or more data packets to be transmitted to the mobile station, extracting at least one data packet, which has a transmission delay time larger than a difference between a maximum delay time and preset margin, from the one or more stored data packets, and transmitting at least a part of the extracted at least one data packet to the mobile station by using a resource allocated to the mobile station.

Abstract: Disclosed is a method and system for transmitting and receiving data in a communication system. The system includes a base station, and a relay station connecting the base station with at least one mobile station. The base station transmits data for a plurality of mobile stations to the relay station, and transmits the data to at least one mobile station belonging to the base station from among the plurality of mobile stations. The relay station receives the data from the base station, and transmits the data to at least one mobile station belonging to the relay station from among the plurality of mobile stations in the same interval as an interval where the base station transmits the data to the mobile station.

Abstract: Disclosed is a system and method for transmitting data based on an operational state of a mobile station in a communication system. The method includes, when detecting a low battery state of the mobile station, storing one or more data packets to be transmitted to the mobile station, extracting at least one data packet, which has a transmission delay time larger than a difference between a maximum delay time and preset margin, from the one or more stored data packets, and transmitting at least a part of the extracted at least one data packet to the mobile station by using a resource allocated to the mobile station.

Abstract: An apparatus and method for transmitting/receiving a Channel Quality Information (CQI) in a communication system are provided. A Mobile Station (MS) receives first information indicating a representative MS selected from a group of MSs located within a preset range and in similar channel statuses, the group including the MS, determines from the first information whether the MS is designated as the representative MS, and transmits a CQI of the MS as a representative CQI of the MSs included in the group to a Base Station (BS), if the MS is designated as the representative MS.