Wireless communications for asymmetric services

1. A method comprising:

determining, by a wireless device:

a first slice service type (SST) for uplink traffic associated with an application; and

a second SST for downlink traffic associated with the application;

sending, by the wireless device to a base station, a first establishment request message for a first packet data unit (PDU) session associated with the first SST;

receiving, by the wireless device from the base station, a first response message indicating, for the first PDU session, an internet protocol (IP) address;

sending, by the wireless device to the base station, a second establishment request message for a second PDU session associated with the second SST, wherein the second establishment request message indicates that the second PDU session is associated with the first PDU session; and

receiving, by the wireless device from the base station, a second response message indicating, for the second PDU session, the IP address.

2. The method of claim 1 , further comprising:

sending, by the wireless device to the base station via the first PDU session, a first data packet comprising the IP address; and

receiving, by the wireless device from the base station via the second PDU session, a second data packet comprising the IP address.

3. The method of claim 1 , wherein the second establishment request message comprises a session correlation indication indicating that the second PDU session is associated with the first PDU session.

4. The method of claim 1 , wherein the second establishment request message indicates that a first network slice for the first PDU session is associated with a second network slice for the second PDU session.

5. The method of claim 1 , wherein the first PDU session is for the uplink traffic and the second PDU session is for the downlink traffic.

6. The method of claim 1 , wherein the second establishment request message indicates that the first PDU session is associated with a first service type and the second PDU session is associated with a second service type different from the first service type.

7. The method of claim 1 , wherein the second establishment request message comprises at least one of:

a PDU session identifier of the first PDU session;

the IP address;

first single network slice selection assistance information (S-NSSAI) of the first PDU session; or

a first network slice instance identifier for the first S-NSSAI.

8. The method of claim 1 , wherein the wireless device sends the first establishment request message and the second establishment request message to an access and mobility management function (AMF) device via the base station.

9. A method comprising:

sending, by a wireless device to a base station, a first establishment request message for a first packet data unit (PDU) session, associated with a first slice service type (SST), for uplink traffic associated with an application;

receiving, by the wireless device from the base station, a first response message indicating, for the first PDU session, an internet protocol (IP) address;

sending, by the wireless device to the base station, a second establishment request message for a second PDU session, associated with a second SST, for downlink traffic associated with the application, wherein the second establishment request message indicates that the second PDU session is associated with the first PDU session;

receiving, by the wireless device from the base station, a second response message indicating, for the second PDU session, the IP address;

sending, by the wireless device to the base station via the first PDU session, a first data packet comprising the IP address; and

receiving, by the wireless device from the base station via the second PDU session, a second data packet comprising the IP address.

10. The method of claim 9 , further comprising determining, based on a service request associated with the application:

the first SST for the uplink traffic associated with the application; and

the second SST for the downlink traffic associated with the application.

11. The method of claim 9 , wherein the second establishment request message comprises a session correlation indication indicating that the second PDU session is associated with the first PDU session.

12. The method of claim 9 , wherein the second establishment request message indicates that a first network slice for the first PDU session is associated with a second network slice for the second PDU session.

13. The method of claim 9 , wherein the first PDU session is for the uplink traffic and the second PDU session is for the downlink traffic.

14. The method of claim 9 , wherein the second establishment request message comprises at least one of:

a PDU session identifier of the first PDU session;

the IP address;

first single network slice selection assistance information (S-NSSAI) of the first PDU session; or

a first network slice instance identifier for the first S-NSSAI.

15. A method comprising:

receiving, by a first device from a second device, a first establishment request message for a first packet data unit (PDU) session, associated with a first slice service type (SST), for uplink traffic of an application;

determining, for the first PDU session, an internet protocol (IP) address;

receiving, from the second device, a second establishment request message for a second PDU session, associated with a second SST, wherein the second establishment request message indicates that the second PDU session is for downlink traffic of the application;

determining, based on the first PDU session and the second PDU session being for a same application, that the IP address is used for the second PDU session; and

sending, to the second device and for the second PDU session, the IP address.

16. The method of claim 15 , wherein the first device is a session management function (SMF) device and the second device is an access and mobility management function (AMF) device.

17. The method of claim 15 , further comprising:

sending, to a first user plane function (UPF) device for the first PDU session, a first user plane rule comprising the IP address; and

sending, to a second UPF device for the second PDU session, a second user plane rule comprising the IP address.

18. The method of claim 15 , wherein the second establishment request message comprises at least one of:

a PDU session identifier of the first PDU session;

the IP address;

first single network slice selection assistance information (S-NSSAI) of the first PDU session; or

a first network slice instance identifier for the first S-NSSAI.

19. The method of claim 15 , wherein the second establishment request message indicates that a first network slice for the uplink traffic is associated with a second network slice for the downlink traffic.

20. The method of claim 15 , wherein the second establishment request message indicates that the first PDU session is associated with a first service type and the second PDU session is associated with a second service type different from the first service type.