Signal transmission and reception method and apparatus and communication system
A signal transmission and reception method and apparatus and a communication system, the signal transmission and reception apparatus being applicable in an IAB-DU and includes a first receiver configured to receive uplink data transmitted to a parent node of an integrated access and backhaul (IAB) node via an uplink; and a first transmitter configured to transmit flow control feedback information to a child node of the integrated access and backhaul node, the flow control feedback information being used to indicate a load status of uplink transmission of the integrated access and backhaul node.
1 . A signal transmission and reception apparatus, applicable in an integrated access and backhaul node distributed unit (IAB-DU), comprising:
a first receiver configured to receive uplink data transmitted to a parent node of an integrated access and backhaul (IAB) node via an uplink; and
a first transmitter configured to transmit flow control feedback information to a child node of the integrated access and backhaul node, the flow control feedback information being used to indicate a load status of uplink transmission of the integrated access and backhaul node,
wherein the flow control feedback information includes the load status of the uplink transmission at a certain granularity.
2 . The apparatus according to claim 1 , wherein,
when a buffer load of the integrated access and backhaul node exceeds a first threshold or the integrated access and backhaul node receives a flow control request of the child node,
the first transmitter transmits the flow control feedback information to the child node.
3 . The apparatus according to claim 1 , wherein,
the first transmitter generates a backhaul adaptation protocol control protocol data unit (BAP control PDU) used for transmitting the flow control feedback information according to a flow control type configured in an F1 application protocol (F1 AP), and transmits the backhaul adaptation protocol control protocol data unit.
4 . The apparatus according to claim 3 , wherein,
in a case where the F1 application protocol has configured an egress backhaul radio link control (BH RLC) channel for the backhaul adaptation protocol control protocol data unit (BAP control PDU), the backhaul adaptation protocol control protocol data unit (BAP control PDU) is submitted to the egress backhaul radio link control (BH RLC) channel,
a backhaul radio link control channel identification information element (BH RLC CH ID IE) of the egress backhaul radio link control (BH RLC) channel is associated with a backhaul adaptation protocol control protocol data unit channel (BAP control PDU channel) information element (IE) with a value being a first value.
5 . The apparatus according to claim 3 , wherein,
a backhaul adaptation protocol (BAP) sublayer of the integrated access and backhaul node comprises a first protocol data unit type (PDU type), and
when the configured flow control is flow control performed by taking a logical channel group (LCG) as a granularity, the first protocol data unit type (PDU type) used by the first transmitter is flow control feedback by taking a logical channel group (LCG) as a granularity.
6 . The apparatus according to claim 1 , wherein,
contents of the flow control feedback information comprise:
an available buffer size; and/or
an available data rate; and/or
indication information used for indicating congestion; and/or
congestion clearance indication information.
7 . The apparatus according to claim 1 , the apparatus further comprising:
a second receiver configured to receive configuration information transmitted by a central unit of the integrated access and backhaul node donor (IAB-donor CU), the configuration information being used to configure a flow control type and/or contents of the flow control feedback information.
8 . The apparatus according to claim 7 , wherein,
the configuration information is transmitted via F1 AP.
9 . A signal transmission and reception apparatus, applicable in an integrated access and backhaul node mobile termination (IAB-MT), comprising:
a third receiver configured to receive flow control feedback information transmitted by a parent node, the flow control feedback information being used to indicate a load status of uplink transmission of the parent node; and
first processor circuitry, set in a backhaul adaption protocol (BAP) entity of the integrated access and backhaul (IAB) node, configured:
to pass down data to a lower layer according to the flow control feedback information, and
not to allocate data contained in the flow control feedback information or corresponding to a congested routing ID to the lower layer.
10 . The apparatus according to claim 9 , wherein,
in a case where the flow control feedback information indicates a congestion status by taking a backhaul radio link control (BH RLC) channel as a granularity,
the first processor circuitry does not pass down data mapped to an egress backhaul radio link control (BH RLC) channel indicated as being in a congestion status to the lower layer.
11 . The apparatus according to claim 9 , wherein,
in a case where the flow control feedback information indicates a congestion status by taking a routing ID as a granularity,
the first processor circuitry does not pass down data with a backhaul adaption protocol (BAP) header containing a routing ID indicated as being in a congestion status to the lower layer.
12 . The apparatus according to claim 9 , wherein,
in a case where the flow control feedback information indicates an available buffer size by taking a backhaul radio link control (BH RLC) channel as a granularity,
the first processor circuitry does not pass down data more than the available buffer size in the data mapped to each backhaul radio link control (BH RLC) channel in the flow control feedback information to the lower layer.
13 . The apparatus according to claim 9 , wherein,
in a case where the flow control feedback information indicates an available buffer size by taking a routing ID as a granularity,
the first processor circuitry, for a routing ID in the flow control feedback information, does not pass down data more than the available buffer size in data with a BAP header containing the routing ID to the lower layer.
14 . The apparatus according to claim 9 , wherein,
in a case where the integrated access and backhaul node receives congestion clearance indication information from the parent node,
the first processor circuitry passes down data to the lower layer according to the congestion clearance indication information;
wherein the congestion clearance indication information is used for indicating that uplink of the parent node is in a normal state.
15 . A signal transmission and reception apparatus, applicable in an integrated access and backhaul node mobile termination (IAB-MT), comprising:
a third receiver configured to receive flow control feedback information transmitted by a parent node, the flow control feedback information being used to indicate a load status of uplink transmission of the parent node; and
second processor circuitry, set in a medium access control (MAC) layer entity of an integrated access and backhaul node, configured:
to perform reporting of a buffer status report (BSR) and/or resource allocation of a logical channel according to the flow control feedback information,
not to calculate buffer information of data mapped to a congested routing ID or BH RLC channel or data corresponding to an LCG indicated as being congestion into the BSR, and/or
not to perform resource allocation on data not included in the BSR, or for data mapped to a congested routing ID or BH RLC channel, or data corresponding to the LCG indicated as being congestion in the LCP process.
16 . The apparatus according to claim 15 , wherein,
in a case where the flow control feedback information indicates a congestion status by taking a backhaul radio link control (BH RLC) channel as a granularity,
the second processor circuitry does not allocate a resource for a logical channel to which a backhaul radio link control (BH RLC) channel indicated as being in a congestion status corresponds.
17 . The apparatus according to claim 15 , wherein,
in a case where the flow control feedback information indicates a congestion status by taking a routing ID as a granularity,
the second processor circuitry does not allocate a resource for data with a backhaul adaptation protocol (BAP) header containing a routing ID indicated as being in a congestion status.
18 . The apparatus according to claim 15 , wherein,
in a case where the flow control feedback information indicates a congestion status by taking a logical channel group (LCG) as a granularity,
the second processor circuitry does not allocate a resource for a logical channel group (LCG) indicated as being in a congestion status.
19 . The apparatus according to claim 15 , wherein,
in a case where the flow control feedback information indicates an available data rate by taking a backhaul radio link control (BH RLC) channel as a granularity,
the second processor circuitry sets a prioritized bit rate (PBR) of a logical channel to which the backhaul radio link control (BH RLC) channel corresponds to be the smaller one in an original PBR of the logical channel and the available data rate.
20 . The apparatus according to claim 15 , wherein,
in a case where the integrated access and backhaul (IAB) node receives congestion clearance indication information from the parent node,
the second processor circuitry performs reporting of the buffer status report (BSR) and resource allocation of the logical channel according to the congestion clearance indication information;
wherein the congestion clearance indication information is used to indicate that uplink of the parent node is in a normal state.