Communication between a UE and wirelessly interconnected base stations

1 . A method in a first base station for communicating with a user equipment (UE) via the first base station and a second base station, the method comprising:

transmitting, via a wireless backhaul link to the second base station, a configuration for concurrent communication between the UE and a group of base stations including the first base station and the second base station,

the configuration directing the second base station to operate in an Active Coordination Set (ACS) with the first base station, the ACS configured to provide joint transmission and/or joint reception to the UE, and

the configuration indicating a time-frequency resource for a second subsequent downlink transmission from the second base station to the UE;

configuring the first base station to operate as an integrated access and backhaul (IAB)-donor and the second base station to operate as an IAB-node; and

communicating data with the UE (i) directly over a radio interface using the time-frequency resource, and (ii) over the wireless backhaul link and via the second base station.

2 . The method of claim 1 , wherein the transmitting includes:

transmitting the configuration to the UE and the second base station, over a shared radio link.

3 . The method of claim 1 , wherein the transmitting includes:

transmitting, to the second base station in a signal including the configuration, data for the second subsequent downlink transmission to the UE.

4 . The method of claim 1 , wherein the configuration indicates, for at least one of a first subsequent downlink transmission from the first base station or the second subsequent downlink transmission from the second base station, one or more of:

(i) a modulation and coding scheme (MCS),

(ii) a beam multiplexing scheme, or

(iii) a frequency multiplexing scheme.

5 . The method of claim 1 , wherein the communicating includes:

jointly transmitting, with the second base station, downlink data over a data channel.

6 . The method of claim 1 , wherein the communicating includes:

receiving a first uplink transmission via the radio interface and a second uplink transmission from the second base station via the wireless backhaul link, the method further comprising:

soft-combining the first uplink transmission with the second uplink transmission to obtain uplink data transmitted from the UE.

7 . The method of claim 6 , further comprising:

buffering the first uplink transmission until the second uplink transmission is received.

8 . A method for supporting concurrent communication between a user equipment (UE) and a group of base stations including a first base station and the second base station, the method implemented in the second base station and comprising:

receiving, from the first base station via a radio interface, a configuration for concurrent communication between the UE and the group of base stations including an indication of a time-frequency resource for a second subsequent downlink transmission to be transmitted from the second base station jointly with a first subsequent downlink transmission from the first base station to the UE;

configuring, in accordance with the configuration, the second base station to operate in an Active Coordination Set (ACS) with the first base station, the ACS configured to provide joint transmission and/or joint reception to the UE;

configuring the second base station to operate as an integrated access and backhaul (IAB)-node with the first base station as a corresponding IAB-donor; and

communicating, in accordance with the configuration, data between the first base station and the UE, including:

communicating the data with the first base station via the radio interface, and

communicating the data with the UE directly over a radio link between the second base station and the UE.

9 . The method of claim 8 , further comprising:

receiving, from the first base station in a signal including the configuration, data for the second subsequent downlink transmission to the UE; and

transmitting the data to the UE via the radio link.

10 . The method of claim 8 , wherein the configuration indicates, for at least one of the first subsequent downlink transmission or the second subsequent downlink transmission, one or more of:

(i) a modulation and coding scheme (MCS),

(ii) a beam multiplexing scheme, or

(iii) a frequency multiplexing scheme.

11 . The method of claim 8 , wherein the configuration indicates an uplink grant for transmitting, via the radio interface, a subsequent uplink transmission received from the UE over the radio link.

12 . The method of claim 8 , wherein the communicating includes:

receiving an uplink transmission from the UE via the radio link; and

transmitting the uplink transmission to the first base station via the radio interface.

13 . An apparatus in a first base station for communicating with a user equipment (UE) via the first base station and a second base station, comprising:

a transceiver;

a memory; and

a processor coupled to the memory and the transceiver, the processor configured to:

transmit, via a wireless backhaul link to the second base station, a configuration for concurrent communication between the UE and a group of base stations including the first base station and the second base station, the configuration directing the second base station to operate in an Active Coordination Set (ACS) with the first base station, the ACS configured to provide joint transmission and/or joint reception to the UE, and the configuration indicating a time-frequency resource for a second subsequent downlink transmission from the second base station to the UE;

configure the first base station to operate as an integrated access and backhaul (IAB)-donor and the second base station to operate as an IAB-node; and

communicate data with the UE (i) directly over a radio interface using the time-frequency resource, and (ii) over the wireless backhaul link and via the second base station.

14 . The apparatus of claim 13 , wherein the processor is further configured to:

transmit the configuration to the UE and the second base station, over a shared radio link.

15 . The apparatus of claim 13 , wherein the processor is further configured to:

transmit, to the second base station in a signal including the configuration, data for the second subsequent downlink transmission to the UE.

16 . The apparatus of claim 13 , wherein the processor is further configured to:

jointly transmit, with the second base station, downlink data over a data channel.

17 . The apparatus of claim 13 , wherein the processor is further configured to:

receive a first uplink transmission via the radio interface and a second uplink transmission from the second base station via the wireless backhaul link; and

soft-combine the first uplink transmission with the second uplink transmission to obtain uplink data transmitted from the UE.

18 . The apparatus of claim 17 , wherein the processor is further configured to:

buffer the first uplink transmission until the second uplink transmission is received.

19 . An apparatus for supporting concurrent communication between a user equipment (UE) and a group of base stations including a first base station and the second base station, the apparatus implemented in the second base station and comprising:

a transceiver;

a memory; and

a processor coupled to the memory and the transceiver, the processor configured to:

receive, from the first base station via a radio interface, a configuration for concurrent communication between the UE and the group of base stations including an indication of a time-frequency resource for a second subsequent downlink transmission to be transmitted from the second base station jointly with a first subsequent downlink transmission from the first base station to the UE;

configure, in accordance with the configuration, the second base station to operate in an Active Coordination Set (ACS) with the first base station, the ACS configured to provide joint transmission and/or joint reception to the UE;

configure the second base station to operate as an integrated access and backhaul (IAB)-node with the first base station as an IAB-donor; and

communicate, in accordance with the configuration, data between the first base station and the UE, including to:

communicate the data with the first base station via the radio interface, and

communicate the data with the UE directly over a radio link between the second base station and the UE.

20 . The apparatus of claim 19 , wherein the processor is further configured to:

receive, from the first base station in a signal including the configuration, data for the second subsequent downlink transmission to the UE; and

transmit the data to the UE via the radio link.

21 . The apparatus of claim 19 , wherein the configuration indicates, for at least one of the first subsequent downlink transmission or the second subsequent downlink transmission, one or more of:

(i) a modulation and coding scheme (MCS),

(ii) a beam multiplexing scheme, or

(iii) a frequency multiplexing scheme.

22 . The apparatus of claim 19 , wherein the configuration indicates an uplink grant for transmitting, via the radio interface, a subsequent uplink transmission received from the UE over the radio link.

23 . The apparatus of claim 19 , wherein the processor is further configured to:

receive an uplink transmission from the UE via the radio link; and

transmit the uplink transmission to the first base station via the radio interface.