Random access method and apparatus therefor
AssigneeLG Electronics Inc.
InventorsJoonkui Ahn, Suckchel Yang, Yunjung Yi
Life of this patent
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Abstract
A disclosure of the present specification provides a random access method for an unlicensed band. The method comprises the steps of: transmitting, by a user equipment (UE), a random access preamble in a first cell of the unlicensed band; and receiving, by the UE, a random access response in a second cell, wherein the second cell may be a first cell, a cell of the unlicensed band, included in a cell group to which the first cell belongs, or a cell of the unlicensed band, included in a timing advance group (TAG) within the cell group, to which the first cell belongs.
Claims4
A random access method for an unlicensed band, the method comprising:
- transmitting, by a user equipment (UE), a random access preamble in a first cell of the unlicensed band;
- and
- receiving, by the UE, a random access response in a second cell,
- wherein the second cell is a cell of the unlicensed band, which is included in a cell group to which the first cell belongs, or a cell of the unlicensed band, which is included in a timing advance group (TAG) within the cell group to which the first cell belongs,
- wherein the second cell is a cell of the unlicensed band in which downlink transmission for the UE is scheduled most quickly after the random access preamble is transmitted in the cell group,
- wherein the random access response includes information related to an uplink transmission timing and a transmit power of the UE, and
- wherein the random access response further includes an uplink (UL) grant that is used to transmit a scheduled message in a third cell,
- adjusting, by the UE, the uplink transmission timing and the transmit power of the UE based on the information included in the random access response;
- and
- transmitting, by the UE, the scheduled message in the third cell according to the UL grant in the random access response,
- wherein the third cell is one of a plurality of licensed band cells or unlicensed band cell that is determined based on information of the first cell related to a cell identifier, a sequence, a timing, and a frequency resource.
An apparatus for performing a random access by using an unlicensed band, the apparatus comprising:
- a transceiver;
- and a processor configured to:
- control the transceiver to transmit a random access preamble in a first cell of the unlicensed band, and control the transceiver to receive a random access response in a second cell,
- wherein the second cell is a cell of the unlicensed band, which is included in a cell group to which the first cell belongs, or a cell of the unlicensed band, which is included in a timing advance group (TAG) within the cell group to which the first cell belongs,
- wherein the second cell is a cell of the unlicensed band in which downlink transmission by a base station is scheduled most quickly after the random access preamble is transmitted in the cell group,
- wherein the random access response includes information related to an uplink transmission timing and a transmit power of the UE, and
- wherein the random access response further includes an uplink (UL) grant that is used to transmit a scheduled message in a third cell,
- adjust the uplink transmission timing and the transmit power of the UE based on the information included in the random access response;
- and
- control the transceiver to transmit the scheduled message in the third cell according to the UL grant in the random access response,
- wherein the third cell is one of a plurality of licensed band cells or unlicensed band cell that is determined based on information of the first cell related to a cell identifier, a sequence, a timing, and a frequency resource.
Dependencies are inferred from the claim text.