Abstract:
Disclosed are channel management methods in a multicarrier structure in a mobile communication system. Uplink (UL) and downlink (DL) channel management methods in a carrier aggregation environment are used as the channel management methods. In DL, a base station determines a component carrier (CC) of an unstable radio channel state, stops data retransmission by the CC, and notifies a terminal of retransmission stop. In UL, the base station determines a CC of an unstable radio channel state and instructs the terminal to stop data retransmission by the CC, and the terminal stops the data retransmission and initializes a retransmission buffer. Using the channel management methods in the mobile communication system employing the multicarrier structure, an increase in the number of unnecessary retransmissions is prevented, so that unnecessary retransmission and power consumption of the terminal can be reduced and the waste of radio resources and the degradation of base station performance due to unnecessary retransmission can be prevented.
Abstract:
Disclosed is a method for transmitting a discovery signal in device-to-device communication. In phase 1, for devices at a long range, a discovery signal is transmitted by dividing a band like in OFDMA, and in phase 2, for devices at a short range, the discovery signal is transmitted by using a full band.
Abstract:
A method and an apparatus for beam failure recovery in a communication system. The method for beam failure recovery includes the steps of: searching for a plurality of candidate beams when a beam failure is detected; transmitting a beam failure recovery request signal to a base station by using beam #1 of the plurality of candidate beams; receiving a beam failure recovery response signal in response to the beam failure recovery request signal via beam #1 from the base station; and transmitting an SR requesting a resource for transmission of multi-beam setting information to the base station, where the multi-beam setting information includes indexes of one or more beams excluding beam #1 of the plurality of candidate beams.
Abstract:
Provided is a method of transmitting and receiving data using a persistent allocation scheme in order to effectively support a voice service between a base station and a mobile terminal in a packet based mobile communication system. When an error occurs in transmitting control information that indicates whether to use a radio resource using the persistent allocation scheme, the base station may retransmit the control information and thereby maintain a communication quality.
Abstract:
Disclosed herein is a device-to-device discovery method in a wireless communication system. A device determines whether a first subframe for a physical layer uplink channel or signal and a second subframe for the discovery signal are the same. The device transmits the physical layer uplink channel or signal without transmitting or receiving the discovery signal, in the same subframe, when the first subframe and the second subframe are the same.
Abstract:
Methods for flow control in a network are disclosed. In a dual connectivity network environment where a master base station and a secondary base station exist, an operation method of a master base station may comprise transmitting a data frame including a plurality of data packets to a secondary base station; receiving, from the secondary base station, a delivery status frame requesting retransmission of error data packet among the plurality of data packets; and retransmitting the error data packet indicated by the delivery status frame to the secondary base station. Therefore, network performance can be enhanced.
Abstract:
There is provided a transmission/reception method of a base station in a device to device (D2D) communication environment in which terminals directly communicate with each other. The base station variably sets the transmission power intensity of a downlink signal over time. Furthermore, the base station broadcasts the downlink signal with set transmission power intensity.
Abstract:
Disclosed is a carrier management method for use in a carrier aggregation environment of a mobile communication system. In the method, a base station is configured to transmit a deactivation message for a secondary carrier to a terminal and change the secondary carrier to a deactivation state after a predetermined time from the transmission of the deactivation message. The terminal receives the deactivation message transmitted by the base station, and changes the secondary carrier to the deactivation state after a predetermined time from the transmission of the deactivation message. As the predetermined time, a predefined value may be used to prevent inconsistency of secondary-carrier state information that is managed by the base station and the terminal. If the carrier state management information is used, it is possible to prevent inconsistency of secondary-carrier states that are managed by the base station and the terminal and solve problems due to the inconsistency.
Abstract:
A device-to-device (D2D) communication method in a wireless mobile communication system is provided. A channel state measurement method for adaptive transmission of cellular network-based D2D communication, a data transmission/reception method of D2D communication, and a power control method for transmission power control of a D2D link in the D2D communication are provided. Specifically, cellular network-based D2D communication methods optimized for a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system are provided. The above-described methods are also applicable to various cellular mobile communication systems as well as the 3GPP LTE system.
Abstract:
Provided is a data transmission system using a carrier aggregation. The data transmission system may assign a radio resource based on a correspondence relationship between a downlink and an uplink, and may transmit data using the assigned radio resource.