NETWORK SLICE RESELECTION
Systems, methods, and instrumentalities are disclosed for network slice selection and/or reselection. A WTRU may receive updated assistance information for network slice selection and/or reselection. The WTRU may apply local policies to determine when to use the updated assistance information to access a network slice. The WTRU may determine whether to contact an existing network slice function or a new network slice function to establish a connection to a network slice. Based on the determination, the WTRU may transmit different information to the network. The network slice selection and/or reselection may be initiated by a WTRU or by a network.
1 . A method implemented in a wireless transmit/receive unit (WTRU), the method comprising:
the WTRU receiving a message from a network, wherein the message comprises updated network slice information for the network;
the WTRU determining that at least a first network slice being utilized by the WTRU can no longer be used by the WTRU based on the updated slice information, wherein the WTRU is served by a first access and mobility management function (AMF) of the network for at least the first network slice, the WTRU having a temporary identifier associated with the first AMF;
the WTRU updating network slice selection assistance information (NSSAI) based on the updated network slice information;
the WTRU determining to replace the first network slice with a second network slice based on the updated network slice information and one or more policies configured for the WTRU;
the WTRU determining whether the first AMF should serve the WTRU for the second network slice; and
the WTRU contacting the first AMF or a second AMF to establish a connection to the second network slice, wherein:
on a condition that the WTRU determines that the first AMF should serve the WTRU for the second network slice, the WTRU transmits a connection or registration message comprising the updated NSSAI to the first AMF, and
on a condition that the WTRU determines that the first AMF should not serve the WTRU for the second network slice, the WTRU deletes the temporary identifier and transmits a connection or registration message comprising the updated NSSAI to the second AMF.
2 . The method of claim 1 , wherein the updated NSSAI identifies a type of service provided by the second network slice.
3 . The method of claim 2 , wherein the type of service includes at least one of an enhanced Mobile Broadband (eMBB) service, an ultra-reliable low latency communications (UR-LLC) service, or a massive Internet of Things (mIoT) service.
4 . The method of claim 1 , wherein, on a condition that the WTRU determines that the first AMF should not serve the WTRU for the second network slice, the method further comprising the WTRU detaching from the first AMF.
5 . The method of claim 1 , wherein the one or more policies include information regarding a list of one or more network slices that the WTRU is permitted to access.
6 . The method of claim 1 , wherein the WTRU determining to replace the first network slice with the second network slice comprises the WTRU selecting the second network slice from the list of one or more network slices that the WTRU is permitted to access.
7 . The method of claim 1 , wherein the message received from the network includes an indication that the first network slice is congested.
8 . The method of claim 7 , further comprising the WTRU waiting for a duration of a back-off timer before contacting the first AMF or the second AMF to establish a connection to the second network slice.
9 . The method of claim 1 , wherein the temporary identifier is included in the connection or registration message sent to the first AMF on a condition that the WTRU determines that the first AMF should serve the WTRU for the second network slice.
10 . The method of claim 1 , wherein the updated network slice information is received in response to a subscription change or a mobility change associated with the WTRU.
11 . A wireless transmit/receive unit (WTRU) comprising:
a processor configured to:
receive a message from a network, wherein the message comprises updated network slice information for the network;
determine that at least a first network slice being utilized by the WTRU can no longer be used by the WTRU based on the updated slice information, wherein the WTRU is served by a first access and mobility management function (AMF) of the network for at least the first network slice, the WTRU having a temporary identifier associated with the first AMF;
update network slice selection assistance information (NSSAI) based on the updated network slice information;
determine to replace the first network slice with a second network slice based on the updated network slice information and one or more policies configured for the WTRU;
determine whether the first AMF should serve the WTRU for the second network slice; and
contact the first AMF or a second AMF to establish the connection to the second network slice, wherein:
on a condition that the WTRU determines that the first AMF should serve the WTRU for the second network slice, the WTRU transmits a connection or registration message comprising the updated NSSAI to the first AMF, and
on a condition that the WTRU determines that the first AMF should not serve the WTRU for the second network slice, the WTRU deletes the temporary identifier and transmits a connection or registration message comprising the updated NSSAI to the second AMF.
12 . The WTRU of claim 11 , wherein the updated NSSAI identifies a type of service provided by the second network slice.
13 . The WTRU of claim 12 , wherein the type of service includes at least one of an enhanced Mobile Broadband (eMBB) service, an ultra-reliable low latency communications (UR-LLC) service, or a massive Internet of Things (mIoT) service.
14 . The WTRU of claim 11 , wherein, on a condition that the WTRU determines that the first AMF should not serve the WTRU for the second network slice, the processor is further configured to detach from the first AMF.
15 . The WTRU of claim 11 , wherein the one or more policies include information regarding a list of one or more network slices that the WTRU is permitted to access.
16 . The WTRU of claim 11 , wherein the processor being configured to determine to replace the first network slice with the second network slice comprises the processor being configured to select the second network slice from the list of one or more network slices that the WTRU is permitted to access.
17 . The WTRU of claim 11 , wherein the message received from the network includes an indication that the first network slice is congested.
18 . The WTRU of claim 17 , wherein the processor is further configured to wait for a duration of a back-off timer before contacting the first AMF or the second AMF to establish a connection to the second network slice.
19 . The WTRU of claim 11 , wherein the temporary identifier is included in the connection or registration message sent to the first AMF on a condition that the WTRU determines that the first AMF should serve the WTRU for the second network slice.
20 . The WTRU of claim 11 , wherein the updated network slice information is received in response to a subscription change or a mobility change associated with the WTRU.