# US 11,445,401 B2 · Session management in wireless communication system

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- Number: US 11,445,401 B2
- Document ID: US11445401B2
- Status: Granted
- Kind: B2
- Application number: 16/795,421
- Filed: 2020-02-19
- Published: 2020-08-27
- Granted: 2022-09-13
- Earliest claimed: 2019-02-22
- Assignees: Mediatek Inc.
- Applicants: Mediatek Inc.
- Inventors: Chien-Chun Huang-Fu; Yu-Chieh Tien; Chi-Hsien Chen; Shang-Ru Mo
- Web page: https://patentgrep.com/patent/US11445401B2

## CPC

- H04W 28/0268: {using specific QoS parameters for wireless networks, e.g. QoS class identifier [QCI] or guaranteed bit rate [GBR] (negotiating SLA or negotiating QoS H04W28/24)}
- H04W 76/22: Manipulation of transport tunnels
- H04W 28/12: using signalling between network elements
- H04W 76/25: Maintenance of established connections
- H04W 80/10: adapted for {application} session management, e.g. SIP [Session Initiation Protocol] {(connection management H04W76/00; arrangements for session management H04L67/14)}
- H04W 76/11: Allocation or use of connection identifiers
- 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 can include receiving a non-access stratum (NAS) message for establishing or modifying a protocol data unit (PDU) session at a user equipment (UE) from a core network, determining whether there is a quality of service (QoS) flow description resulting from the establishment or modification of the PDU session that is associated with a guaranteed bit rate (GBR) QoS flow of the PDU session, and invalid, and when it is determined that there is the invalid QoS flow description associated with the GBR QoS flow of the PDU session, performing an error handling operation.

## Claims

### Claim 1

A method, comprising:
receiving a non-access stratum (NAS) message for establishing or modifying a protocol data unit (PDU) session at a user equipment (UE) from a core network;
determining there is an invalid quality of service (QoS) flow description resulting from the establishment or modification of the PDU session upon
the NAS message including a flow description operation of create new QoS flow description or modify existing QoS flow description, and
determining that the QoS flow description is associated with a guaranteed bit rate (GBR) QoS flow of the PDU session and lacks at least one of mandatory parameters; and
upon determining that there is the invalid QoS flow description, performing an error handling operation to handle the invalid QoS flow description,
wherein the error handling operation includes:
when there is no default QoS rule associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, if a QoS rules Information Element (IE) of the NAS message contains at least one valid QoS rule, or a QoS flow description IE of the NAS message contains at least one other valid QoS flow description, further processing one or more requests corresponding to the at least one valid QoS rule, or the at least one other valid QoS flow description without diagnose an error to trigger a reject to the NAS message,
completing a procedure for establishing or modifying the PDU session,
deleting the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters, and
initiating a UE requested PDU session modification procedure by sending a PDU session modification request message with a 5G session management (5GSM) cause #84 syntactical error in the QoS operation to delete the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters.

### Claim 2 (depends on 1)

The method of claim 1, wherein the mandatory parameters include:
guaranteed flow bit rate for uplink (GFBR UL),
guaranteed flow bit rate for downlink (GFBR DL),
maximum flow bit rate for uplink (MFBR UL), and
maximum flow bit rate for downlink (MFBR DL).

### Claim 3 (depends on 1)

The method of claim 1, wherein
the QoS flow description is determined to be associated with the GBR QoS flow when a 5G QoS identifier (5QI) in the QoS flow description has a GBR resource type or a delay-critical GBR resource type, or when a QoS flow identifier (QFI) in the QoS flow description has a value of a 5QI having a GBR resource type or a delay-critical GBR resource type.

### Claim 4 (depends on 1)

The method of claim 1, wherein the NAS message is a PDU session modification command message, or a PDU session establishment accept message.

### Claim 5 (depends on 1)

The method of claim 1, wherein the error handling operation includes:
when the invalid QoS flow description associated with the GBR QoS flow of the PDU session is associated with a default QoS rule of the PDU session, initiating a process to release the PDU session.

### Claim 6

A method, comprising:
receiving a protocol data unit (PDU) session modification command message from a core network requesting a flow description operation at a user equipment (UE) during a PDU session modification procedure;
when the flow description operation is create a new Quality of Service (QoS) flow description, or modify existing QoS flow description, determining there is an invalid QoS flow description of a guaranteed bit rate (GBR) QoS flow upon determining that the QoS flow description of the GBR QoS flow lacks at least one of mandatory parameters; and
upon determining that there is the invalid QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, performing an error handling operation to handle the invalid QoS flow description,
wherein the error handling operation includes:
when there is no default QoS rule associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, if a QoS rules Information Element (IE) of the PDU session modification command message contains at least one valid QoS rule, or a QoS flow description IE of the PDU session modification command message contains at least one other valid QoS flow description, further processing one or more requests corresponding to the at least one valid QoS rule, or the at least one other valid QoS flow description without diagnose an error to trigger a reject to the PDU session modification command message,
completing the PDU session modification procedure,
deleting the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters, and
initiating a UE requested PDU session modification procedure by sending a PDU session modification request message with a 5G session management (5GSM) cause #84 syntactical error in the QoS operation to delete the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters.

### Claim 7 (depends on 6)

The method of claim 6, wherein the mandatory parameters include:
guaranteed flow bit rate for uplink (GFBR UL),
guaranteed flow bit rate for downlink (GFBR DL),
maximum flow bit rate for uplink (MFBR UL), and
maximum flow bit rate for downlink (MFBR DL).

### Claim 8 (depends on 6)

The method of claim 6, wherein the error handling operation includes:
when a default QoS rule of the PDU session is associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, initiating a PDU session release procedure by sending a PDU session release request message with the 5G session management (5GSM) cause #84, syntactical error in the QoS operation.

### Claim 9

A method, comprising:
receiving a protocol data unit (PDU) session establishment accept message from a core network requesting a flow description operation at a user equipment (UE) during a PDU session establishment procedure requested by the UE;
when the flow description operation is create a new Quality of Service (QoS) flow description, determining there is an invalid QoS flow description of a guaranteed bit rate (GBR) QoS flow upon determining that the QoS flow description of the GBR QoS flow lacks at least one of mandatory parameters; and
upon determining that there is the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, performing an error handling operation to handle the invalid QoS flow description,
wherein the error handling operation includes:
when a default QoS rule of the PDU session is associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, initiating a PDU session release procedure by sending a PDU session release request message with a 5G session management (5GSM) cause #84 syntactical error in the QoS operation,
when there is no default QoS rule associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, initiating a UE requested PDU session modification procedure by sending a PDU session modification request message with the 5G session management (5GSM) cause #84 syntactical error in the QoS operation to delete the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters.

### Claim 10 (depends on 9)

The method of claim 9, wherein the mandatory parameters include:
guaranteed flow bit rate for uplink (GFBR UL),
guaranteed flow bit rate for downlink (GFBR DL),
maximum flow bit rate for uplink (MFBR UL), and
maximum flow bit rate for downlink (MFBR DL).

### Claim 11 (depends on 9)

The method of claim 9, wherein the error handling operation includes:
when there is no default QoS rule associated with the QoS flow description of the GBR QoS flow which lacks at least one of the mandatory parameters, if a QoS rules IE of the PDU session establishment accept message contains at least one valid QoS rule, or a QoS flow description IE of the PDU session contains at least one other valid QoS flow description, further processing one or more requests corresponding to the at least one valid QoS rule, or the at least one other valid QoS flow description.

### Claim 12 (depends on 9)

The method of claim 9, wherein the error handling operation includes:
deleting the QoS flow description which lacks at least one of the mandatory parameters and one or more QoS rules, if any, associated with the QoS flow description which lacks at least one of the mandatory parameters.