Performing listen-before-talk procedure during random access procedure
AssigneeOfinno, LLC
InventorEsmael Hejazi Dinan
Life of this patent
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Abstract
A wireless device initiates a random access procedure on an unlicensed cell. A listen-before-talk (LBT) procedure, for transmission of a preamble of the random access procedure, is performed. In response to the LBT procedure indicating a clear channel, the wireless device: transmits the preamble via a random access channel (RACH) of the unlicensed cell, and monitors a physical downlink control channel (PDCCH) for a random access response (RAR). In response to the LBT procedure indicating an LBT failure, the wireless device: does not monitor the PDCCH for the RAR, and performs a random access resource selection procedure.
Claims20
A method comprising:
- initiating, by a wireless device, a random access procedure on an unlicensed cell;
- performing a listen-before-talk (LBT) procedure for transmission of a preamble of the random access procedure;
- in response to the LBT procedure indicating a clear channel:
- transmitting the preamble via a random access channel (RACH) of the unlicensed cell;
- and
- monitoring a physical downlink control channel (PDCCH) for a random access response (RAR);
- and
- in response to the LBT procedure indicating an LBT failure:
- not monitoring the PDCCH for the RAR;
- and
- performing a random access resource selection procedure.
A wireless device comprising:
- one or more processors;
- and
- memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
- initiate a random access procedure on an unlicensed cell;
- perform a listen-before-talk (LBT) procedure for transmission of a preamble of the random access procedure;
- in response to the LBT procedure indicating a clear channel:
- transmit the preamble via a random access channel (RACH) of the unlicensed cell;
- and
- monitor a physical downlink control channel (PDCCH) for a random access response (RAR);
- and
- in response to the LBT procedure indicating an LBT failure:
- not monitor the PDCCH for the RAR;
- and
- perform a random access resource selection procedure.
A method comprising:
- transmitting, by a base station to a wireless device, a control order to initiate a random access procedure on an unlicensed cell;
- in response to a listen-before-talk (LBT) procedure indicating a clear channel for uplink transmission of a first preamble of the random access procedure:
- receiving, by the base station, the preamble via a random access channel (RACH) of the unlicensed cell;
- and
- transmitting, by the base station, a physical downlink control channel (PDCCH) for a random access response (RAR);
- and
- in response to the LBT procedure indicating an LBT failure:
- not transmitting, by the base station, the PDCCH for the RAR;
- and
- receiving, by the base station, a second preamble based on a random access resource selection procedure.
Dependencies are inferred from the claim text.