Use of FDD SCell to mitigate interference to uplink TDD PCell

1 . A method comprising:

determining, by a gNodeB (gNB), that interference to an uplink time division duplexing (TDD) carrier between a user equipment (UE) and a PCell of the gNB exceeds a threshold; and

in response to the determining, instructing, by the gNB, the UE to move uplink TDD traffic from the uplink TDD carrier to an uplink FDD carrier with an SCell of the gNB, with the UE connected to both the PCell and SCell using carrier aggregation,

wherein the moving is performed without switching the PCell to an FDD carrier.

2 . The method of claim 1 , further comprising determining that the interference has fallen below the threshold and, in response, instructing the UE to move the uplink TDD traffic back to the uplink TDD carrier.

3 . The method of claim 1 , wherein the interference is caused by tropospheric ducting.

4 . The method of claim 1 , wherein the determining is based at least in part on a predicted interference level or on a signal to interference and noise ratio.

5 . The method of claim 1 , wherein the instructing includes a scheduler of the gNB instructing the UE to send the uplink TDD traffic over the uplink FDD carrier while maintaining the uplink TDD carrier.

6 . The method of claim 1 , further comprising determining a congestion measure for the uplink FDD carrier and performing the instructing of the UE to move the uplink TDD traffic based at least in part on the congestion measure.

7 . The method of claim 6 , further comprising, when the congestion measure exceeds a threshold, either refraining from performing the instructing of the UE to move the uplink TDD traffic or adding a second SCell of the gNB and instructing the UE to move the uplink TDD traffic to an uplink FDD carrier with the second SCell.

8 . A gNodeB (gNB) comprising:

one or more processors; and

a plurality of programming instructions that, when executed by the one or more processors cause the gNB to perform operations including:

determining that interference to an uplink time division duplexing (TDD) carrier between a user equipment (UE) and a PCell of the gNB exceeds a threshold; and

in response to the determining, instructing the UE to move uplink TDD traffic from the uplink TDD carrier to an uplink FDD carrier with an SCell of the gNB, with the UE connected to both the PCell and SCell using carrier aggregation,

wherein the moving is performed without switching the PCell to an FDD carrier.

9 . The gNB of claim 8 , wherein the operations further comprise determining that the interference has fallen below the threshold and, in response, instructing the UE to move the uplink TDD traffic back to the uplink TDD carrier.

10 . The gNB of claim 8 , wherein the interference is caused by tropospheric ducting.

11 . The gNB of claim 8 , wherein the determining is based at least in part on a predicted interference level or on a signal to interference and noise ration.

12 . The gNB of claim 8 , wherein the instructing includes a scheduler of the gNB instructing the UE to send the uplink TDD traffic over the uplink FDD carrier while maintaining the uplink TDD carrier.

13 . The gNB of claim 8 , wherein the operations further comprise determining a congestion measure for the uplink FDD carrier and performing the instructing of the UE to move the uplink TDD traffic based at least in part on the congestion measure.

14 . The gNB of claim 13 , wherein the operations further comprise, when the congestion measure exceeds a threshold, either refraining from performing the instructing of the UE to move the uplink TDD traffic or adding a second SCell of the gNB and instructing the UE to move the uplink TDD traffic to an uplink FDD carrier with the second SCell.

15 . A non-transitory computer storage medium having a plurality of programming instructions stored thereon that, when executed by one or more processors of a gNodeB (gNB) cause the gNB to perform operations comprising:

determining that interference to an uplink time division duplexing (TDD) carrier between a user equipment (UE) and a PCell of the gNB exceeds a threshold; and

in response to the determining, instructing the UE to move uplink TDD traffic from the uplink TDD carrier to an uplink FDD carrier with an SCell of the gNB, with the UE connected to both the PCell and SCell using carrier aggregation,

wherein the moving is performed without switching the PCell to an FDD carrier.

16 . The non-transitory computer storage medium of claim 15 , wherein the operations further comprise determining that the interference has fallen below the threshold and, in response, instructing the UE to move the uplink TDD traffic back to the uplink TDD carrier.

17 . The non-transitory computer storage medium of claim 15 , wherein the determining is based at least in part on a predicted interference level or on a signal to interference and noise ration.

18 . The non-transitory computer storage medium of claim 15 , wherein the instructing includes a scheduler of the gNB instructing the UE to send the uplink TDD traffic over the uplink FDD carrier while maintaining the uplink TDD carrier.

19 . The non-transitory computer storage medium of claim 15 , wherein the operations further comprise determining a congestion measure for the uplink FDD carrier and performing the instructing of the UE to move the uplink TDD traffic based at least in part on the congestion measure.

20 . The non-transitory computer storage medium of claim 19 , wherein the operations further comprise, when the congestion measure exceeds a threshold, either refraining from performing the instructing of the UE to move the uplink TDD traffic or adding a second SCell of the gNB and instructing the UE to move the uplink TDD traffic to an uplink FDD carrier with the second SCell.