US 12,075,305 B2
User plane setup during 5G system to evolved packet system handover
Qian Chen, Mölndal (SE); Juying Gan, Shanghai (CN); Stefan Rommer, Västra Frölunda (SE); Ann-Christine Sander, Skepplanda (SE); and Paul Schliwa-Bertling, Ljungsbro (SE)
Assigned to Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Filed on Feb. 22, 2023, as Appl. No. 18/112,865.
Application 18/112,865 is a division of application No. 17/268,396, abandoned, previously published as PCT/CN2019/100377, filed on Aug. 13, 2019.
Claims priority of application No. PCT/CN2018/100512 (WO), filed on Aug. 14, 2018.
Prior Publication US 2023/0284114 A1, Sep. 7, 2023
Int. Cl. H04W 36/00 (2009.01); H04W 8/08 (2009.01); H04W 36/32 (2009.01); H04W 48/16 (2009.01)
CPC H04W 36/32 (2013.01) [H04W 8/08 (2013.01); H04W 36/0022 (2013.01); H04W 48/16 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method for handover of one or more Protocol Data Unit, PDU, sessions of a User Equipment, UE, from a 5th Generation, 5G, System, 5GS, to an Evolved Packet System, EPS, wherein the one or more PDU sessions comprise at least one PDU session without a User Plane, UP, connection, the method comprising:
at a Next Generation Radio Access Network, NG-RAN, node of the 5GS:
sending, to an Access and Mobility Function, AMF, of the 5GS, a handover required message for handover of the UE to an Evolved Universal Terrestrial Radio Access Network, E-UTRAN, of the EPS, the handover required message comprising a source to target transparent container that comprises information that indicates one or more bearers corresponding to 5G Quality of Service, QoS, flows for data forwarding;
at the AMF:
receiving the handover required message from the NG-RAN node; and
sending a forward relocation request to a Mobility Management Entity, MME, of the EPS, the forward relocation request comprising Packet Data Network, PDN, connection information for one or more Session Management Functions, SMFs, holding the at least one PDU session without a UP connection;
at the MME:
receiving the forward relocation request from the AMF; and
sending, to an E-UTRAN node of the EPS, a handover request, the handover request comprising information that indicates one or more bearers requested by the MME for the handover; and
at the E-UTRAN node:
receiving the handover request from the MME; and
for each bearer of the one or more bearers requested by the MME in the handover request, allocating resources for the bearer even if the bearer is not one of the one or more bearers indicated in the source to target transparent container.