Back to results
US 2020/0404708 A1Published application
Channel Access Mechanism for Random Access Channel in Unlicensed Spectrum
AssigneeHuawei Technologies Co., Ltd.
InventorsJiayin Zhang, Mohamed Adel Salem, Liqing Zhang
Life of this patent
Estimating the term…
Abstract
Method and devices are provided for a channel access mechanism for accessing a network on a random access channel (RACH). Methods involve defining a listen-before-talk (LBT) category to be used as part of a contention based procedure and how a contention window that is part of the LBT can be dynamically adjusted.
Claims20
A method for wireless communications occurring in an unlicensed spectrum for accessing a network, the method comprising:
- transmitting, by an apparatus, a first message in a random access channel (RACH) resource, the first message including a random access preamble;
- and
- setting, by the apparatus, a contention window size (CWS) for a listen-before-talk (LBT) category 4 (CAT4) contention procedure or type 1 UL channel access procedure for an uplink (UL) transmission subsequent to the first message, the UL transmission to be based on receipt of a second message to be received from a base station during a specified message reception time window.
A method for wireless communications occurring in an unlicensed spectrum for accessing a network comprising:
- transmitting, by an apparatus, a first message in a random access channel (RACH) resource, the first message including a random access preamble and using a category 4 (CAT4) contention procedure having a contention window size (CWS);
- receiving, by the apparatus, a second message from a base station that includes an indication that a type of listen-before-talk (LBT) contention procedure to be used for a subsequent uplink (UL) transmission is CAT4;
- and
- maintaining, by the apparatus, the CWS used for a first UL transmission for the subsequent UL transmission.
1 more element
A method for wireless communications occurring in an unlicensed spectrum comprising:
- transmitting in a four step procedure for accessing a random access channel (RACH), by an apparatus, a first message including a random access preamble;
- in response to the first message, receiving, by the apparatus, a second message from a base station including an uplink (UL) grant and an indication of a type of listen-before-talk (LBT) contention procedure that the apparatus is to use for a third message;
- transmitting, by the apparatus, the third message on a granted UL resource;
- and
- in response to the third message, receiving, by the apparatus, a fourth message from the base station.
2 more elements
A method for wireless communications occurring in an unlicensed spectrum comprising:
- transmitting in a two-step procedure for accessing a network, by a base station to an electronic device (ED), configuration information, the configuration information comprising one or more of:
- an indication of a time-frequency resource on a random access channel (RACH) at which the ED may transmit a first message, the indication comprising a physical random access channel (PRACH) starting offset to transmit a PRACH preamble inside or outside of base station acquired channel occupancy time (COT),
- an indication of a time-frequency resource allocation in an uplink data channel comprising one or more of:
- a physical uplink shared channel (PUSCH) starting position, or a PUSCH ending symbol,
- a channel access type, or
- a channel access priority class.
3 more elements
An apparatus comprising:
- one or more processors;
- and
- a non-transitory computer readable storage medium storing programming for execution by the one or more processors, the programming including instructions to:
- transmit a first message in a random access channel (RACH) resource, the first message including a random access preamble;
- and
- set a contention window size (CWS) for a listen-before-talk (LBT) category 4 (CAT4) contention procedure or type 1 UL channel access procedure for an uplink (UL) transmission subsequent to the first message, the UL transmission to be based on receipt of a second message to be received from a base station during a specified message reception time window.
3 more elements
An apparatus comprising:
- one or more processors;
- and
- a non-transitory computer readable storage medium storing programming for execution by the one or more processors, the programming including instructions to:
- transmit a first message in a random access channel (RACH) resource, the first message including a random access preamble and using a category 4 (CAT4) contention procedure having a contention window size (CWS);
- receive a second message from a base station that includes an indication that a type of listen-before-talk (LBT) contention procedure to be used for a subsequent uplink (UL) transmission is CAT4;
- and
- maintain the CWS used for a first UL transmission for the subsequent UL transmission.
4 more elements
An apparatus comprising:
- one or more processors;
- and
- a non-transitory computer readable storage medium storing programming for execution by the one or more processors, the programming including instructions to:
- transmit in a four step procedure for accessing a random access channel (RACH) a first message including a random access preamble;
- in response to the first message, receive a second message from a base station including an uplink (UL) grant and an indication of a type of listen-before-talk (LBT) contention procedure that the apparatus is to use for a third message;
- transmit the third message on a granted UL resource;
- and
- in response to the third message, receive, a fourth message from the base station.
5 more elements
A base station comprising:
- one or more processors;
- and
- a non-transitory computer readable storage medium storing programming for execution by the one or more processors, the programming including instructions to:
- transmit in a two-step procedure for accessing a network, to an electronic device (ED), configuration information, the configuration information comprising one or more of:
- an indication of a time-frequency resource on a random access channel (RACH) at which the ED may transmit a first message, the indication comprising a physical random access channel (PRACH) starting offset to transmit a PRACH preamble inside or outside of base station acquired channel occupancy time (COT),
- an indication of a time-frequency resource allocation in an uplink data channel comprising one or more of:
- a physical uplink shared channel (PUSCH) starting position, or a PUSCH ending symbol,
- a channel access type, or
- a channel access priority class.
6 more elements
Dependencies are inferred from the claim text.