Abstract: 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.

Abstract: 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.

Abstract: A terminal executes a random access procedure with a target base station depending on a pre-random access channel (pre-RACH) command in a handover preparation step executed between a source base station currently accessed by the terminal and the target base station when the terminal receives the pre-RACH command from the source base station through layer2 (L2) signaling in the handover preparation step.

Abstract: A ground radio station (GRS) apparatus and a radio station apparatus included in an unmanned aerial vehicle (UAV) are provided. The GRS apparatus may include an antenna configured to transmit and receive a radio frequency (RF) signal, an RF and/or intermediate frequency (IF) (RF/IF) chain configured to perform a conversion between the RF signal and a baseband signal, a baseband transceiving processor configured to transmit and receive the baseband signal, and a BB-IF interface configured to map the baseband signal to the RF/IF chain or the baseband transceiving processor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method in which a terminal that supports a multi-carrier manages a primary carrier, including: receiving a primary carrier change command from a base station; and changing the primary carrier from a serving primary carrier to a target primary carrier.

Abstract: A method and apparatus of receiving system information of an SeNB, including configuring connection to an MeNB and receiving a RRC Connection Reconfiguration message including the system information of a cell included in a SCG controlled by the SeNB, and a method of sharing frame offset between a MCG controlled by an MeNB and an SCG controlled by an SeNB connected to the MeNB through non-ideal backhaul, including measuring system frame number (SFN) and subframe number (SN) of a cell included in the SCG and sharing the frame offset, which is determined based on the SFN and the SN, with the MeNB or the SeNB are provided.

Abstract: A transmitter in a mobile communication system configures a short transmission time interval (TTI) using some transmission symbols in a subframe including a plurality of transmission symbols, multiplexes and transmits a reference signal and some of transmission data in a first symbol of the transmission symbols having the short TTI, and transmits the remainder of the transmission data in the remaining symbols except the first symbol.

Abstract: Disclosed herein are a method and an apparatus for transmitting an uplink signal. The method for transmitting an uplink signal includes: transmitting an uplink data in at least one symbol included in a short transmit time interval (sTTI) including 7 symbols or less; and transmitting a demodulation reference signal (DMRS) for the uplink data through an even-numbered subcarrier or an odd-numbered subcarrier in one symbol in which the uplink data is not transmitted, among the symbols included in the sTTI.

Abstract: Disclosed herein is a method for configuring a subframe by a transmitting apparatus in a mobile communication system, including: configuring the subframe consisting of a downlink control information transmission interval in which control information of a downlink is transmitted, a data transmission interval in which data are transmitted, an uplink control information transmission interval in which control information of an uplink is transmitted, and a response signal transmission interval in which a response signal to data reception is transmitted; and transmitting the subframe.

Abstract: A terminal executes a random access procedure with a target base station depending on a pre-random access channel (pre-RACH) command in a handover preparation step executed between a source base station currently accessed by the terminal and the target base station when the terminal receives the pre-RACH command from the source base station through layer2 (L2) signaling in the handover preparation step.

Abstract: Provided are a method and an apparatus for requesting uplink persistent scheduling in a mobile communication system. A terminal generates a semi-persistent scheduling (SPS) buffer status report (BSR) including a size of data and further including at least one of an SPS transmission point in time and an SPS period after configuring SPS between the terminal and a base station, and requests SPS allocation while transmitting the SPS BSR to the base station. The size of the data indicates a size of data that are to be transmitted per SPS period.

Abstract: A communication system configured to send data using an interference alignment scheme is disclosed herein. The disclosed communication system includes an MS and a BS. The disclosed BS sends data using a transmission beamforming matrix that minimizes intra-cell interference. The disclosed MS receives the data using a reception beamforming matrix that minimizes inter-cell interference. The BS sends information about a reference beamforming matrix to the MS, and sends a pilot signal to the MS using the reference beamforming matrix. The MS estimates an effective channel using the reference beamforming matrix, and calculates the intensity of an interference signal from an interference BS.

Abstract: A communication method for a third device that controls a first link established directly between a first device and a second device is provided. The third device allocates a first link identifier for identifying the first link. The third device transmits first information including the first link identifier to the first device and the second device. The third device receives, from the first device and the second device, second information including allocation acceptance information indicating the acceptance or rejection of allocation of the first link identifier.

Abstract: A base station defines a short TTI (transmission time interval) equal to the length of one subslot as the minimum unit of a time resource for data transmission in a subframe including a plurality of subslots, determines the RS type the terminal will use for transmission, among a plurality of RS types, based on the positions of RSs (reference signals) within the short TTI, and sends information on the RS type the terminal will use for transmission to the terminal.

Abstract: A method and an apparatus for transmitting the physical uplink control channel including an uplink control channel expressed by product of a uplink control information and a sequence and demodulation reference signal expressed by a sequence having different cyclic shift values through a short resource block are provided.

Abstract: Disclosed is an authentication method of a wireless mesh network capable of reducing overload and communication delay during authentication procedure by performing authentication between nodes without accessing an authentication server. The authentication method of a wireless mesh network according to an exemplary embodiment of the present disclosure includes: selecting, by a new node, a first neighbor node among one or more adjacent nodes; transmitting, by the new node, an authentication request message including a public key of the new node; authenticating, by the first neighbor node, the public key of the new node; transmitting, by the first neighbor node, an authentication response message including a public key of the first neighbor node to the new node; and authenticating, by the new node, the public key of the first neighbor node; transmitting, by the new node, an authentication identification message to the first neighbor node.

Abstract: Disclosed herein are a method of beamforming and a 3D antenna array. The method includes: transmitting a first control channel; receiving first feedback information on a first antenna set and a first precoding scheme of a plurality of antenna sets included in the 3D antenna array, which are determined based on the first control channel, from a first communication node different from the communication node; and beamforming a traffic channel to be transmitted to the first communication node using the first antenna set and the first precoding scheme.