Network Slice Mobility Management

A second base station (BS), comprising one or more processors and memory storing instructions that, when executed by the one or more processors, cause the second base station to:

• receive, from a core network node and in response to sending a path switch request message, a path switch acknowledge message comprising one or more identifiers of one or more partially allowed network slices for a wireless device, wherein the one or more partially allowed network slices are not supported in one or more tracking area (TAs) of a registration area (RA) of the wireless device;
• determine, based on a third BS supporting the one or more partially allowed network slices, a handover of the wireless device to the third BS;
• and
• send, to the third BS, and based on the determining, a handover request message comprising the one or more identifiers.

A method comprising:

• receiving, by a wireless device:
• one or more system information blocks comprising one or more identifiers of one or more tracking area (TAs) of a registration area (RA) of the wireless device;
• and
• one or more non-access stratum (NAS) messages comprising one or more slice identifiers of one or more partially allowed network slices for the wireless device;
• receiving, from a first base station (BS), a first radio resource control (RRC) message indicating handover to a second cell of a second BS;
• sending, to the second BS, a second RRC message indicating completion of the handover;
• receiving, from the second BS, a third RRC message indicating a second handover to a third cell of a third BS supporting the one or more partially allowed network slices, wherein:
• the one or more slice identifiers of the one or more partially allowed network slices are indicated by a path switch acknowledge message;
• and
• the one or more partially allowed network slices are unsupported in the one or more TAs of the RA;
• and
• sending, to the third BS, a fourth RRC message indicating completion of the second handover.