NR PDCP preservation upon RRC resume/suspend

1. A method for use in a user equipment (UE) of resuming a radio bearer in a wireless communication network, the method comprising:

establishing a radio resource control (RRC) connection with a network node, including establishing a signaling radio bearer 1 (SRB1) with a Packet Data Convergence Protocol (PDCP) configuration corresponding to a first radio access technology;

responsive to receiving a connection suspend message from the network node, storing the PDCP configuration and suspending SRB1;

after suspending SRB1, converting SRB1 to a second PDCP configuration corresponding to a second radio access technology;

responsive to receiving a connection resume message via the SRB1, determining whether the connection resume message includes PDCP configuration information corresponding to the first radio access technology for SRB1;

upon determining the connection resume message includes the PDCP configuration information corresponding to the first radio access technology, configuring SRB1 with the PDCP configuration; and

resuming SRB1.

2. The method of claim 1 , wherein the first radio access technology comprises New Radio (NR).

3. The method of claim 1 , wherein the second radio access technology comprises Long Term Evolution (LTE).

4. The method of claim 1 , wherein the connection resume message is received from a second network node that is different than the network node.

5. The method of claim 1 , wherein configuring SRB1 comprises using the PDCP configuration information in the connection resume message and the stored PDCP configuration.

6. The method of claim 5 , wherein the PDCP configuration information in the connection resume message takes precedence over the stored PDCP configuration.

7. The method of claim 1 , wherein the PDCP configuration information in the connection resume message includes security information different from a previous security information used prior to suspension of SRB1.

8. The method of claim 7 , wherein the security information comprises security key information or security algorithm information.

9. A user equipment (UE) capable of resuming a radio bearer in a wireless communication network, the UE comprising processing circuitry operable to:

establish a radio resource control (RRC) connection with a network node, including establishing a signaling radio bearer 1 (SRB1) with a Packet Data Convergence Protocol (PDCP) configuration corresponding to a first radio access technology;

responsive to receiving a connection suspend message from the network node, store the PDCP configuration and suspend SRB1;

after suspending SRB1, establish SRB1 with convert SRB1 to a second PDCP configuration corresponding to a second radio access technology;

responsive to receiving a connection resume message via the SRB1, determine whether the connection resume message includes PDCP configuration information corresponding to the first radio access technology for SRB1;

upon determining the connection resume message includes the PDCP configuration information corresponding to the first radio access technology, configure SRB1 with the PDCP configuration; and

resume SRB1.

10. The user equipment of claim 9 , wherein the first radio access technology comprises New Radio (NR).

11. The user equipment of claim 9 , wherein the second radio access technology comprises Long Term Evolution (LTE).

12. The user equipment of claim 9 , wherein the connection resume message is received from a second network node that is different than the network node.

13. The user equipment of claim 9 , wherein the processing circuitry is operable configure SRB1 by using the PDCP configuration information in the connection resume message and the stored PDCP configuration.

14. The user equipment of claim 13 , wherein the PDCP configuration information in the connection resume message takes precedence over the stored PDCP configuration.

15. The user equipment of claim 9 , wherein the PDCP configuration information in the connection resume message includes security information different from a previous security information used prior to suspension of SRB1.

16. The user equipment of claim 15 , wherein the security information includes security key information or security algorithm information.

17. A non-transitory computer readable medium having stored thereon machine-readable instructions executable to cause a machine to perform operations comprising:

establishing a radio resource control (RRC) connection with a network node, including establishing a signaling radio bearer 1 (SRB1) with a Packet Data Convergence Protocol (PDCP) configuration corresponding to a first radio access technology;

responsive to receiving a connection suspend message from the network node, storing the PDCP configuration and suspending SRB1;

after suspending SRB1, converting SRB1 to a second PDCP configuration corresponding to a second radio access technology;

responsive to receiving a connection resume message via the SRB1, determining whether the connection resume message includes PDCP configuration information corresponding to the first radio access technology for SRB1;

upon determining the connection resume message includes the PDCP configuration information corresponding to the first radio access technology, configuring SRB1 with the PDCP configuration; and

resuming SRB1.

18. The non-transitory computer readable medium of claim 17 , wherein the first radio access technology comprises New Radio (NR).

19. The non-transitory computer readable medium of claim 17 , wherein the second radio access technology comprises Long Term Evolution (LTE).