Patent ID: 11937140
Assignee: APPLE INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. A cellular network element, comprising:
a network port; and
a processor coupled to the network port;
wherein the cellular network element is configured to:
establish a protocol data unit (PDU) session with a wireless device;
transmit, to the wireless device, signaling indicating one or more quality of service (QoS) flow descriptions for the PDU session with the wireless device;
determine that the PDU session may flow at least in part between the wireless device and a long term evolution (LTE) base station;
receive, from the wireless device, a request for modification of the one or more QoS flow descriptions for the PDU session; and
provide a PDU session modification reject message in response to the request for modification, wherein the PDU session modification reject message includes a cause code for invalid mapped evolved packet service (EPS) bearer QoS, and wherein the invalid mapped EPS bearer QoS is associated with an incorrect QoS;
receive a service request from the wireless device, wherein the service request is for one or more network services or applications that are not supported by a fifth generation core (5GC) network but are supported by an evolved packet core (EPC) network; and
transmit, to the wireless device, a PDU session release message indicating to release the PDU session, wherein the PDU session release message includes a cause code indicating to fallback to evolved packet service (EPS), and wherein the PDU session release message further includes a mapped EPS bearer context information element indicating EPS bearer mapping information for the PDU session.