Use of estimated arrival probability-related information to select target secondary nodes for early data forwarding for dual connectivity wireless communications

1 . A method comprising:

transmitting, by a master node (MN) to a target-secondary node (T-SN), a request for the target-secondary node (T-SN) to prepare a set of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) for a conditional PSCell change for the user device; and

transmitting, by the master node (MN) to a source-secondary node (S-SN) that provides dual connectivity for a user device, information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN),

wherein the information indicating or relating to an arrival probability is transmitted within a Xn-U Address Indication message.

2 . The method of claim 1 , further comprising:

receiving, by the master node (MN) from the source-secondary node (S-SN), a request for assistance information;

wherein the transmitting, by the master node (MN) to a source-secondary node, information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN), is performed based on the request for the assistance information.

3 . The method of claim 1 , wherein the information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN), comprises at least one of the following:

an estimated arrival probability for the user device to or towards the target-secondary node (T-SN);

information indicating a subset of target-secondary nodes (T-SNs) that the user device may access or connect to;

a priority value relating to or associated with the arrival probability of the cell change for the user device to the target-secondary node (T-SN); or

reference signal measurements performed by the user device of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) of the target-secondary node (T-SN) and location information of the user device to enable the source-secondary node (S-SN) to determine a target PSCell and/or a target secondary node (T-SN) that the user device may likely access or perform cell change to.

4 . The method of claim 1 , wherein:

the transmitting the request comprises transmitting, by the master node (MN) to each of a plurality of target-secondary nodes (T-SNs), a request for the target-secondary node (T-SN) to prepare a set of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) for a conditional PSCell change for the user device; and

the transmitting the information comprises transmitting, by the master node (MN) to the source-secondary node (S-SN) for each of the plurality of target-secondary nodes (T-SNs), information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN) to allow the source-secondary node (S-SN) to select a subset of the target-secondary nodes (T-SNs) for early data forwarding.

5 . An apparatus comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

transmit, by a master node (MN) to a target-secondary node (T-SN), a request for the target-secondary node (T-SN) to prepare a set of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) for a conditional PSCell change for the user device; and

transmit, by the master node (MN) to a source-secondary node (S-SN) that provides dual connectivity for a user device, information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN),

wherein the information indicating or relating to an arrival probability is transmitted within a Xn-U Address Indication message.

6 . The apparatus of claim 5 , further comprising:

receiving, by the master node (MN) from the source-secondary node (S-SN), a request for assistance information;

wherein the transmitting, by the master node (MN) to a source-secondary node, information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN), is performed based on the request for the assistance information.

7 . The apparatus of claim 5 , wherein the information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN), comprises at least one of the following:

an estimated arrival probability for the user device to or towards the target-secondary node (T-SN);

information indicating a subset of target-secondary nodes (T-SNs) that the user device may access or connect to; a priority value relating to or associated with the arrival probability of the cell change for the user device to the target-secondary node (T-SN); or reference signal measurements performed by the user device of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) of the target-secondary node (T-SN) and location information of the user device to enable the source-secondary node (S-SN) to determine a target PSCell and/or a target secondary node (T-SN) that the user device may likely access or perform cell change to.

8 . The apparatus of claim 5 , wherein:

the transmitting the request comprises transmitting, by the master node (MN) to each of a plurality of target-secondary nodes (T-SNs), a request for the target-secondary node (T-SN) to prepare a set of one or more candidate target primary cells of a secondary cell group (candidate target PSCells) for a conditional PSCell change for the user device; and

the transmitting the information comprises transmitting, by the master node (MN) to the source-secondary node (S-SN) for each of the plurality of target-secondary nodes (T-SNs), information indicating or relating to an arrival probability of a cell change for the user device to the target-secondary node (T-SN) to allow the source-secondary node (S-SN) to select a subset of the target-secondary nodes (T-SNs) for early data forwarding.

9 . A method comprising:

receiving, by a source-secondary node (S-SN) within a wireless network that is in communication with a user device as part of dual connectivity, information indicating that a conditional PSCell change has been configured for the user device for one or more candidate target primary cells of a secondary cell group (candidate target PSCells) controlled by each of a plurality of target-secondary nodes (T-SNs);

receiving, by the source-secondary node (S-SN) from a master node (MN), information indicating or relating to an arrival probability of a cell change for the user device to a candidate target PSCell controlled by one or more of the plurality of the target-secondary nodes (T-SNs); and

selecting, by the source-secondary node (S-SN) based on the received information, a subset of the plurality of target-secondary nodes (T-SNs) to perform early data forwarding from the source-secondary node (S-SN),

wherein the information indicating or relating to an arrival probability is transmitted within a Xn-U Address Indication message.

10 . The method of claim 9 , further comprising: performing, by the source-secondary node (S-SN) before a cell change has been performed, early data forwarding from the source-secondary node (S-SN) to each of the target-secondary nodes (T-SNs) of the selected subset.

11 . The method of claim 9 , further comprising: transmitting, by the source-secondary node (S-SN) to the master node (MN) a request for assistance information;

wherein the information indicating or relating to an arrival probability of a cell change is received by the source-secondary node (S-SN) based on the request for the assistance information.

12 . The method of claim 9 , wherein the information indicating or relating to an arrival probability of a cell change for the user device to a candidate target PSCell controlled by one or more of the plurality of the target-secondary nodes (T-SNs); comprises at least one of the following:

an estimated arrival probability for the user device for one or more of the plurality of the target-secondary nodes (T-SNs);

information indicating a subset of the plurality of target-secondary nodes (T-SNs) that the user device may access or connect to;

priority values relating to or associated with the arrival probability of the cell change for the user device to a candidate target PSCell(s) controlled by one or more of the plurality of target-secondary node (T-SNs); or

reference signal measurements performed by the user device of one or more PSCells controlled by the plurality the target-secondary node (T-SNs) and location information of the user device to enable the source-secondary node (S-SN) to determine a target PSCell and/or a target secondary node (T-SN) that the user device may likely access or perform cell change to.