Electronics and Telecommunications Research Institute

Tae Chul Hong

Hee Wook Kim

Kwang Jae Lim

Ho Jin Lee

Do-Seob Ahn

Kun Seok Kang

Kunseok Kang

Do Seob Ahn

Disclosed is a channel assignment method of a communication system for controlling an unmanned aerial vehicle (UAV), the method including receiving assignment data and an interference analysis criterion from a spectrum authority; performing an interference analysis and selecting a control and non-payload communication (CNPC) channel based on the assignment data and the interference analysis criterion; and requesting the spectrum authority for assigning the CNPC channel.

Method of assigning channel for UAS control and non-payload communication (CNPC) system

A channel access method in an unmanned aerial vehicle (UAV) control and non-payload communication (CNPC) system is provided. The channel access method may include setting an uplink frequency and a downlink frequency to each of a ground station and an airborne radio station, and performing, by the ground station and the airborne radio station, an initial access using the uplink frequency or the downlink frequency.

Channel access method in unmanned aerial vehicle (UAV) control and non-payload communication (CNPC) system

A handover method and a control transfer method are provided. A handover method of performing an inter-cell handover between a first ground station and a second ground station may include setting a first channel to the second ground station, measuring, by an airborne radio station, a second channel and reporting a measurement result to the first ground station, sending, by the first ground station, a handover request to at least one of a ground control station (GCS) or a control and non-payload communication (CNPC) network, determining, by the at least one of the GCS or the CNPC network, whether to perform a handover, and transmitting, by the at least one of the GCS or the CNPC network, a handover instruction to the airborne radio station based on a result of the determining.

Handover method and control transfer method

In a satellite and terrestrial integrated communication system in which a satellite communication system and a terrestrial communication system share and use an identical frequency band, an interference to a mobile earth station (MES) of the satellite communication system using an identical frequency by an uplink signal transmitted to a base station of the terrestrial communication system by a user equipment (UE) may be mitigated. When a communication of the MES is requested, a satellite communication apparatus to perform resource block (RB) allocation for a satellite communication in the satellite and terrestrial integrated system may include a controller configured to allocate a first RB to the MES, and a communicator configured to transmit a use notification of the first RB to at least one terrestrial base station located in an interference range of an uplink signal of the MES.

Apparatus and method for uplink power control of satellite and terrestrial integrated communication system

A system and method for wireless communication that schedules a connection time of a terminal based on a delay time is provided. A base station of the system for wireless communication may include a delay time determiner to determine a delay time of a terminal, based on preamble information for a plurality of terminal groups based on location information of the terminal, and a scheduler to schedule a connection time for the terminal to connect to the base station, using the delay time.

System and method for random access wireless communication

A memory management method for receiving a multi channel hybrid automatic repeat request (HARQ) packet may enable smooth communication and reduce costs by maintaining a small memory size of a receiver in a communication system using a HARQ including a plurality of channels.

Memory management method and apparatus for receiving multi channel hybrid automatic repeat request (HARQ) packet

In a satellite communication system having a long round-trip delay time, a user terminal reports initial buffer status information when the communication between the satellite and the use terminal started. When a trigger, a timer or padding requiring buffer status information report is generated, the user terminal checks whether there are data to be re-transmitted due to transmission failure from the previous BSR. When transmission-failed data exists, the user terminal sets buffer status amount, which is reported through BSR, as a value that is obtained by adding the amount of transmission-failed data to the amount of newly added after previous report. When there are no transmission-failed data, the user terminal reports BSR which is set as the amount of newly added data to the buffer after previous report. For discriminating entire buffer status reporting and the increased amount of data reporting, the reserved index of a header file is used.

Buffer status reporting method for uplink scheduling and communication system using the same

Provided are a mobile communication system and a cell reselection method of a mobile communication terminal. The mobile communication system includes two or more communication systems using different transmission modes and a mobile communication terminal connectable to the two or more communication systems. The mobile communication terminal measures received signal strength of a satellite communication cell when being switched to an idle mode, divides priority of a satellite communication system using the measured received signal strength and location information of the mobile communication terminal, and sets a first threshold value necessary for cell reselection of the satellite communication system.

Mobile communication system and cell reselection method thereof

Disclosed is a hierarchical random access method for a wireless communication system having a significantly large cell. According to the present invention, a length of a preamble sequence and a length of a reference slot may be designed based on a terminal having greatest capacity of adjusting a timing error arrived at a base station, and a slot length may be designed to be an integer multiple of the length of the reference slot depending on a timing error correction capacity, thereby enabling terminals to use various slot lengths.

Hierarchical random acces method for wireless communication system having significantly large cell

Disclosed is an interaction method between an automatic repeat request (ARQ) and a hybrid automatic repeat request (HARQ) in a system having a long roundtrip delay. A transmission window for the ARQ is operated using inner feedback information from the HARQ, and a waiting window is operated using ARQ status information.

Interaction method between ARQ and HARQ for systems with long roundtrip delay

A method and mobile communication terminal for handover in a mobile communication network including at least one mobile communication base station and a communication satellite. The handover method includes the steps of: (a) calculating a signal power received from a currently communicating mobile communication base station among the at least one mobile communication base station, (b) calculating a signal power received from each of the communication satellite and the at least one mobile communication base station except the base station of step (a), (c) selecting a mobile communication base station having the highest among the calculated signal powers except the signal power received from the communication satellite and the signal power received from the base station of step (a), and (d) when the signal power calculated in step (a) is below a predetermined minimum handover power, a difference between the signal power of the selected mobile communication base station and the signal power calculated in step (a) is equal to or below a first terrestrial handover sensitivity, and there is no other mobile communication base station capable of communicating with the mobile communication terminal, performing handover to the communication satellite.

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Daejeon, South Korea

Tae Chul Hong