US 12,256,274 B2
Evolved packet core to 5G core roaming using N9 interface
Irfan Ali, Palo Alto, CA (US); Ravi Shankar Mantha, Bangalore (IN); Ravi Kiran Guntupalli, Cumming, GA (US); and Jis Abraham, Bangalore (IN)
Assigned to Cisco Technology, Inc., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Jun. 22, 2022, as Appl. No. 17/846,729.
Claims priority of application No. 202121046119 (IN), filed on Oct. 10, 2021.
Prior Publication US 2023/0114175 A1, Apr. 13, 2023
Int. Cl. H04W 36/00 (2009.01); H04M 15/00 (2024.01); H04W 8/02 (2009.01); H04W 36/30 (2009.01); H04W 92/06 (2009.01)
CPC H04W 36/0066 (2013.01) [H04M 15/8038 (2013.01); H04W 8/02 (2013.01); H04W 36/0016 (2013.01); H04W 36/304 (2023.05); H04W 92/06 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system for supporting roaming between LTE Evolved Packet Core (EPC) network and 5G network of a first mobile network operator by stand alone (SA) 5G core (5GC) network of a second network operator, the system comprising:
at least one memory, storing instructions, which when executed by the system, cause the system to:
determine that a UE is attempting to connect to an LTE network operated by the first mobile network operator;
establish a connection between a serving gateway of the LTE network of the first mobile network operator with a Visited Session Management Function (vSMF) of the 5G network of the first mobile network operator by communicating over an S5 interface for control plane;
communicate between the serving gateway and the vSMF to anchor mobility between the LTE network and the 5G network in the vSMF;
communicate between the vSMF and home SMF (hSMF) in a home operator using 5G roaming interfaces comprising interfaces N9 and N16;
communicate with the hSMF, by the vSMF, over the N16 interface for control plane to configure quality of service rules for handover between the LTE network and the 5G network;
form a N9 tunnel from a home User Plane Function (hUPF) of the 5GC network of the second network operator to a visited user plane function (vUPF) of the 5G network of the first mobile network operator for forwarding indirect data;
form a S5 tunnel from the vUPF of the 5G network of the first mobile network operator to the serving gateway of the LTE network of the first mobile network operator; and
forward the indirect data from the hUPF of the 5GC network of the second network operator during handover between the LTE network and the 5G network using the S5 tunnel in the first mobile network operator.