Abstract:
A method for performing random access in a wireless communication system is provided. The method includes transmitting a preamble for random access in uplink, receiving a random access response message including back-off information as a response to the preamble, and performing back-off using the back-off information when the random access has failed.
Abstract:
The present invention provides a method of receiving a timing advance command by a user equipment in a wireless communication system. A terminal receives information on a time advance group from a base station, and also receives the tuning advance command corresponding to the time advance group from the base station.
Abstract:
A method for random access to a base station by a user equipment (UE) in a mobile communication system using carrier aggregation in which communication is conducted over a plurality of component carriers, and a terminal for the method are disclosed. When the UE performs a contention-based random access procedure in the mobile communication system to which CA technology is applied, the UE considers an uplink grant signal as a contention resolution message when receiving the uplink grant signal from a eNB only when the uplink grant signal is received through a downlink CC corresponding to an uplink CC used to transmit a random access preamble or a third message, to thereby prevent contention resolution from being erroneously ended.
Abstract:
A method is described for operating a device in a wireless communication system. The device communicates with a base station using a subframe for the device only; detects, by the device, a problem with a connection between the device and the base station. The device starts a timer upon detecting the problem with the connection between the device and the base station. The device releases a restriction of using the subframe for the device only, if the timer expires. The problem with the connection between the device and the base station is associated with a radio link failure. The detection of a problem with the connection between the device and the base station comprises detecting consecutive out-of-sync indications.
Abstract:
A method of performing contention resolution associated with a random access procedure includes transmitting, by the mobile communication terminal, a random access preamble; receiving, by the mobile communication terminal, a random access response; transmitting, by the mobile communication terminal, an uplink message and starting a contention resolution timer once the uplink message is transmitted; and receiving, by the mobile communication terminal, a physical downlink control channel (PDCCH), wherein the mobile communication terminal considers whether a contention resolution is successful or not by using either a cell radio network temporary identity (C-RNTI) on the PDCCH or a UE Contention Resolution Identity on a downlink shared channel (DL-SCH) associated with the PDCCH, wherein the mobile communication terminal considers the contention resolution successful and stops the contention resolution timer when the C-RNTI on the PDCCH matches the uplink message, and when the UE Contention Resolution Identity on the DL-SCH matches the uplink message.
Abstract:
A method for random access to a base station by a user equipment (UE) in a mobile communication system using carrier aggregation in which communication is conducted over a plurality of component carriers, and a terminal for the method are disclosed. When the UE performs a contention-based random access procedure in the mobile communication system to which CA technology is applied, the UE considers an uplink grant signal as a contention resolution message when receiving the uplink grant signal from a eNB only when the uplink grant signal is received through a downlink CC corresponding to an uplink CC used to transmit a random access preamble or a third message, to thereby prevent contention resolution from being erroneously ended.
Abstract:
There is provided a method for enabling a user equipment (UE) to transition between a non-discontinuous reception (Non-DRX) level and at least one discontinuous reception (DRX) level. The UE in a DRX level wakes up periodically to monitor a scheduling channel. The method includes receiving a DRX indicator in a Non-DRX level with continuously monitoring the scheduling channel and transitioning from the Non-DRX level to a DRX level indicated by the DRX indicator. The UE can transition between multiple DRX levels by an explicit command/signaling.
Abstract:
A method of processing control information in a mobile communication system is disclosed, by which an RRC connection setup can be quickly completed and by which control information can be processed without an unnecessary standby of a mobile terminal. The present invention includes the steps of receiving a plurality of protocol data units transmitted plural time from a transmitting side via one common logical channel by an RLC (radio link control) entity operating in a UM (unacknowledged mode) and having a receiving window and a timer, reordering a plurality of the received protocol data units using sequence numbers of a plurality of the received protocol data units, the receiving window and the timer, reassembling at least one service data unit by processing a plurality of the re-ordered protocol data units, and delivering the at least one service data unit.
Abstract:
A method for transmitting radio resources in a mobile communication system is disclosed. The method includes receiving a random access channel (RACH) preamble from a plurality of UEs and transmitting response information associated with the received preambles over a common channel wherein the plurality UEs can access the common channel and receive corresponding information. If a HARQ scheme is used when a UE transmits data to the eNode-B using uplink radio resources allocated over the RACH, the eNode-B does not pre-allocate uplink radio resources required for re-transmission and performs allocation of radio resources for a first transmission of HARQ. If the re-transmission is required, the eNode-B allocates the radio resources required for the re-transmission with the NACK signal. If re-transmission is not required, the present invention can reduce an amount of wasted radio resources.
Abstract:
According to one embodiment, a method of performing a re-establishment procedure in a mobile communication system includes: receiving at least one packet data convergence protocol (PDCP) control plane data unit; performing an integrity check on the at least one PDCP control plane data unit; identifying an integrity check failure with regard to the at least one PDCP control plane data unit; and performing a re-establishment procedure if the integrity check failure is identified to exist with regard to the at least one PDCP control plane data unit.