Abstract:
There are provided a method for processing an exceptional case of establishing a default bearer and a device therefor in order to solve a problem in that a user equipment cannot actually receive an IP service by accessing a packet network while failing in establishing the default bearer in a mobile communication system. A method for processing an exceptional case of establishing a default bearer in a mobility management entity includes: receiving a network attachment request from a user equipment; transmitting a network attachment acceptance including an activation request of the default bearer to the user equipment in response to the network attachment request; and cancelling a network attachment procedure when a completion response to the activation request of the default bearer is not received from the user equipment within a predetermined time.
Abstract:
Disclosed are a method and an apparatus for controlling distributed transmission power in device-to-device (D2D) communication. The D2D devices individually control their transmission power for the D2D communication link. In addition, a first terminal calculates the transmission power based on the measured channel gain and interference-plus-noise level. The first terminal determines optimal transmission power based on the calculated transmission power by the first terminal, and transmits a transmission power change message including the optimal transmission power to a second terminal. Next, the second terminal transmits a D2D signal based on the optimal transmission power.
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:
A method for synchronization by a D2D terminal in a D2D communication network through receiving a first D2D synchronization signal from at least one D2D synchronization source and performing synchronization according to a synchronization timing reference provided through the first D2D synchronization signal, and a method for negotiating whether to perform a role as a synchronization source with another D2D synchronization source through determining, when a D2D synchronization signal and a D2D synchronization channel are received from at least one D2D synchronization source, whether to maintain a role as the independent synchronization source based on negotiation information for negotiation between synchronization sources included in the D2D synchronization channel, and operating as a relaying synchronization source when the role as the independent synchronization source is not maintained, are provided.
Abstract:
A communication method of a terminal and a base station including a relay is provided. When the terminal attempts a connection to the base station, relays on a communication path include and transmit identifiers thereof in a first message, and the relays and the base station can simply set a communication path to the terminal. When the base station transmits data to the terminal, if the base station includes and transmits an identifier of the terminal in the data, each relay that is located on a communication path forwards data through a preset communication path.