Systems and methods for buffer-based new radio dual connectivity setup

1 . A method performed by a master node (MN), comprising:

transmitting, by a master node central unit control plane (MN CU-CP) to a master node central unit user plane (MN CU-UP), a downlink buffer monitoring request message, wherein the downlink buffer monitoring request message indicates a threshold time;

receiving, by the MN CU-CP and from the MN CU-UP, a downlink buffer monitoring response message, wherein the downlink buffer monitoring response message indicates one or more data radio bearers (DRBs) having downlink buffers that exceed a data threshold by the threshold time, and wherein the downlink buffer monitoring response message indicates respective downlink buffer sizes of the downlink buffers;

receiving, by the MN CU-CP, and via a master node distributed unit (MN DU), a measurement report of a user equipment (UE) associated with a downlink buffer size among the respective downlink buffer sizes, wherein the measurement report is associated with secondary node (SN) candidates; and

establishing, by the MN CU-CP and based on the measurement report, a New Radio dual connectivity (NR-DC) for the UE by adding an SN from the SN candidates.

2 . The method of claim 1 , wherein the downlink buffer monitoring request message indicates a request for a monitoring of a downlink buffer status of the one or more DRBs, and the monitoring is without the NR-DC.

3 . The method of claim 1 , wherein the downlink buffer monitoring request message indicates a downlink buffer threshold and a periodic or trigger-based response request.

4 . The method of claim 1 , further comprising:

ranking, by the MN CU-CP, the UE, among a plurality of UEs, based on the UE being associated with a largest downlink buffer size among the respective downlink buffer sizes, wherein a request for the measurement report is transmitted to the UE based on the ranking of the UE.

5 . The method of claim 1 , further comprising:

transmitting, by the MN CU-CP and to the SN candidates, a request for a report regarding a potential capacity gain resulting from adding the SN candidates; and

selecting, by the MN CU-CP, the SN from the SN candidates based on the potential capacity gain associated with the SN, wherein the SN is a top-ranked SN from the SN candidates in terms of potential capacity gain.

6 . The method of claim 1 , wherein the UE is a first UE and the measurement report is a first measurement report, and further comprising:

transmitting, by the MN CU-CP to the MN DU, a request for the first measurement report of the first UE associated with a largest downlink buffer size among the respective downlink buffer sizes; and

transmitting, by the MN CU-CP to the MN DU, a request for a second measurement report of a second UE associated with a next largest downlink buffer size among the respective downlink buffer sizes;

receiving, by the MN CU-CP and from the second UE, the second measurement report; and

establishing, by the MN CU-CP and based on the second measurement report, an NR-DC for the second UE.

7 . The method of claim 1 , further comprising:

stopping, by the MN CU-CP, the NR-DC for the UE by removing the SN, wherein the SN is removed based on a downlink buffer associated with the UE no longer exceeding the threshold.

8 . The method of claim 1 , wherein a downlink buffer is associated with the MN CU-UP.

9 . A method performed by a master node (MN), comprising:

transmitting, by a master node central unit control plane (MN CU-CP) and to a master node distributed unit (MN DU), an uplink buffer monitoring request message, wherein the uplink buffer monitoring request message indicates a threshold time;

receiving, by the MN CU-CP and from the MN DU, an uplink buffer monitoring response message, wherein the uplink buffer monitoring response message indicates, for a user equipment (UE), a data radio bearer (DRB) having an uplink buffer that exceeds a data threshold for a time longer than the threshold time, wherein the uplink buffer monitoring response message indicates a corresponding uplink buffer size, and wherein the uplink buffer monitoring response message indicates a measurement report of the UE associated with secondary node (SN) candidates; and

establishing, by the MN CU-CP and based on the uplink buffer monitoring response message, a New Radio dual connectivity (NR-DC) for the UE by adding an SN from the SN candidates.

10 . The method of claim 9 , wherein the uplink buffer monitoring request message indicates a request for a monitoring of an uplink buffer status of the DRB, and the monitoring is without the NR-DC.

11 . The method of claim 9 , wherein the uplink buffer monitoring request message indicates an uplink buffer threshold and a periodic or trigger-based response request.

12 . The method of claim 9 , further comprising:

ranking, by the MN CU-CP, the UE, among a plurality of UEs, based on the UE being associated with a largest uplink buffer size among the plurality of UEs.

13 . The method of claim 9 , further comprising:

transmitting, by the MN CU-CP and to the SN candidates, a request for a report regarding a potential capacity gain resulting from adding the SN candidates; and

selecting, by the MN CU-CP, the SN from the SN candidates based on the potential capacity gain associated with the SN, wherein the SN is a top-ranked SN from the SN candidates in terms of potential capacity gain.

14 . The method of claim 9 , wherein the UE is a first UE, wherein the uplink buffer monitoring response message indicates, for a second UE, a DRB having an uplink buffer that exceeds the data threshold for the time longer than the threshold time, and wherein the second UE is associated with a next largest uplink buffer size among a plurality of UEs, and further comprising:

establishing, by the MN CU-CP, an NR-DC for the second UE.

15 . The method of claim 9 , further comprising:

stopping, by the MN CU-CP, the NR-DC for the UE by removing the SN, wherein the SN is removed based on an uplink buffer associated with the UE no longer exceeding the threshold.

16 . The method of claim 9 , wherein an uplink buffer is associated with the UE.

17 . A device, comprising:

one or more processors coupled to a memory storing instructions, configured to:

transmit, by the device, a buffer monitoring request message, wherein the buffer monitoring request message indicates a threshold time;

receive, by the device, a buffer monitoring response message, wherein the buffer monitoring response message indicates one or more data radio bearers (DRBs) having buffers that exceed a data threshold for a time longer than the threshold time, and wherein the buffer monitoring response message indicates respective buffer sizes;

receive, by the device, a measurement report of a user equipment (UE) associated with a buffer size among the respective buffer sizes, wherein the measurement report is associated with secondary node (SN) candidates; and

establish, by the device and based on the measurement report, a New Radio dual connectivity (NR-DC) for the UE by adding an SN from the SN candidates.

18 . The device of claim 17 , wherein a buffer status is an indication of a potential upcoming quality of experience (QoE) deterioration, wherein the potential upcoming QoE deterioration is related to a delay longer than allowed in a quality of service (QOS) policy.

19 . The device of claim 17 , wherein the buffers include one of downlink buffers or uplink buffers.

20 . The device of claim 17 , wherein the device is a master node (MN).