Method, device, and system for core network device re-allocation in wireless network
This disclosure generally relates performing UE authentication and registration with the core network, and in particular, to supporting secure interactions between the UE and the target AMF when the UE is re-allocated to the target AMF from an initial AMF. The Access Network element stores a candidate AMF list, and optionally, the original Registration Request message from the UE. The initial AMF, once determines an AMF re-allocation is needed, instruct the UE to re-start the registration procedure with the core network according to the stored candidate AMF list. With the solutions provided in this disclosure, the message interactions between the UE and the target AMF are integrity protected, without the need to upgrade the UE and without using an indirect connection of the core network.
1 . A method for performing secure re-allocation of a User Equipment (UE) from an initial core network element to a target core network element in a communication network, performed by an access network element, the method comprising:
receiving, from the UE, a third initial UE message indicative of registration request, the third initial UE message being used for requesting registration with the initial core network element;
receiving a first message comprising a candidate core network element list from the initial core network element, the candidate core network element list comprising the target core network element;
storing the candidate core network element list and the third initial UE message;
transmitting, to the initial core network element, a response message to the first message;
receiving, from the UE, a first initial UE message indicative of registration request, the first initial UE message being and being used for requesting registration with the target core network element;
selecting the target core network element from the candidate core network element list; and
transmitting a second initial UE message indicative of registration request to the target core network element, wherein the second initial UE message is based on the third initial UE message and triggers a registration procedure between the UE and the target core network element.
2 . The method of claim 1 , wherein before receiving the first initial UE message, the method further comprises:
transmitting, by the initial core network element to the UE, a second message indicative of registration; and
in response to receiving the second message, transmitting, by the UE, the first initial UE message to the access network element.
3 . The method of claim 2 , wherein the second message comprises one of:
a UE configuration update command carrying a registration indication;
a registration accept message carrying a registration indication; or
a registration reject message.
4 . The method of claim 1 , wherein the access network element comprises one of a gNodeB (gNB), an evolved NodeB (eNB), or a nodeB.
5 . The method of claim 1 , wherein the initial core network element comprises an Access and Mobility Management Function (AMF).
6 . The method of claim 1 , wherein the target core network element comprises an AMF.
7 . The method of claim 1 , wherein the first message comprises a Non Access Stratum (NAS) message.
8 . A computer program product comprising a non-transitory computer-readable program medium with computer code stored thereupon, the computer code, when executed by one or more processors, causing the one or more processors to implement a method of claim 1 .
9 . A network node comprising a memory for storing computer instructions and a processor in communication with the memory, wherein, when the processor executes the computer instructions, the processor is configured to cause the network node to:
receive, from the UE, a third initial UE message indicative of registration request, the third initial UE message being used for requesting registration with the initial core network element;
receive a first message comprising a candidate core network element list from an initial core network element, the candidate core network element list comprising a target core network element;
store the candidate core network element list and the third initial UE message;
transmit, to the initial core network element, a response message to the first message;
receive, from the UE, a first initial UE message indicative of registration request, the first initial UE message being used for requesting registration with the target core network element;
select the target core network element from the candidate core network element list; and
transmit a second initial UE message indicative of registration request to the target core network element, wherein the second initial UE message is based on the third initial UE message and triggers a registration procedure between the UE and the target core network element.