# US 12,772,157 B2 · Method for network node and network node

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- Number: US 12,772,157 B2
- Document ID: US12772157B2
- Status: Granted
- Kind: B2
- Application number: 18/445,769
- Filed: 2022-06-01
- Published: 2024-08-01
- Granted: 2026-10-20
- Earliest claimed: 2021-06-25
- Assignees: NEC Corporation
- Applicants: NEC Corporation
- Inventors: Iskren Ianev; Toshiyuki Tamura; Kundan Tiwari
- Web page: https://patentgrep.com/patent/US12772157B2

## CPC

- H04W 48/18: Selecting a network or a communication service
- H04W 36/0022: {for transferring data sessions between adjacent core network technologies}
- H04W 36/13: {Cell handover without a predetermined boundary, e.g. virtual cells}
- H04W 36/144: {over a different radio air interface technology}
- H04W 48/16: Discovering, processing access restriction or access information
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method of a Session Management Function (SMF) apparatus includes communicating with a Network Slice Admission Control Function (NSACF) apparatus and sending a message to the NSACF apparatus for a Network Slice Admission Control (NSAC). The message includes information related to a handover from Evolved Packet System (EPS) to 5th Generation System (5GS) and information indicating the NSACT is not supported in the EPS.

## Claims

### Claim 1

A method performed by a Network Slice Admission Control Function (NSACF), the method comprising:
receiving, from an Access and Mobility Management Function (AMF), a request including an identifier of a User Equipment (UE);
based on UE admission being above a threshold, checking a presence of an indication in the request, wherein the indication is related to the UE already being registered and mobility of the UE from an Evolved Packet System (EPS) to a 5G System (5GS); and
based on the presence of the indication in the request, accepting the request.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
updating a number of UE registered for a network slice in a case where the indication is present.

### Claim 3 (depends on 1, 2)

The method according to claim 1 or claim 2, wherein the threshold is a threshold level related to a maximum number of UE registered with a Single Network Slice Selection Assistance Information (S-NSSAI).

### Claim 4

A Network Slice Admission Control Function (NSACF) comprising:
a memory storing instructions; and
at least one processor configured to process the instructions to:
receive, from an Access and Mobility Management Function (AMF), a request including an identifier of a User Equipment (UE),
based on UE admission being above a threshold, check a presence of an indication in the request, wherein the indication is related to the UE already being registered and mobility of the UE from an Evolved Packet System (EPS) to a 5G System (5GS), and
based on the presence of the indication in the request, accept the request.

### Claim 5 (depends on 4)

The NSACF according to claim 4, wherein the at least one processor is further configured to process the instructions to:
update of a number of UE registered for a network slice in a case where the indication is present.

### Claim 6 (depends on 4, 5)

The NSACF according to claim 4 or claim 5, wherein the threshold is a threshold level related to a maximum number of UE registered with a Single Network Slice Selection Assistance Information (S-NSSAI).