Method and user equipment for performing attach request procedure

Patent metadata

Field	Value
Publication number	US-11178589-B2
Application number	US-201816769166-A
Country	US
Kind code	B2
Filing date	Dec 31, 2018
Priority date	Jan 2, 2018
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

One disclosure of the present specification provides a method in which a user equipment (UE) performs an attach request procedure. The method comprises a step of transmitting an attach request message to a second system when an intersystem change from a first system to the second system is required in a state where a back-off timer associated with a data network name (DNN) based congestion control is running. The attach request message may include information on a packet data unit (PDU) session used by the UE in the first system. The information on the PDU session may be used so as not for the attach request message to be rejected by a second network, even if the back-off timer associated with the DNN-based congestion control is running.

First claim

What is claimed is:

1. A method for performing an attach request procedure, the method performed by a user equipment (UE) and comprising:
transmitting an attach request message to a second system when an intersystem change from a first system to the second system is required in a state where a back-off timer associated with a data network name (DNN) based congestion control is running,
wherein the attach request message includes information on a packet data unit (PDU) session used by the UE in the first system, and
the information on the PDU session is used so as not for the attach request message to be rejected by a second network, even if the back-off timer associated with the DNN-based congestion control is running.

2. The method of claim 1 , further comprising:
overriding the back-off timer which is running when the intersystem change from the first system to the second system is required.

3. The method of claim 1 , wherein the information on the PDU session includes identification information for one or more PDU sessions used in the first system.

4. The method of claim 1 , wherein the information on the PDU session is included in an information element field in the attach request message.

5. The method of claim 1 , wherein the information on the PDU session is included in a protocol configuration option (PCO) in a session management (SM) container in the attach request message.

6. The method of claim 1 , wherein the first network is a 5 th generation system (5GS) and the second network is an evolved packet system (EPS).

7. A method for performing an attach request procedure, the method performed by a mobility management entity (MME) and comprising:
receiving an attach request message from user equipment (UE) which requires an intersystem change from a first system to a second system in a state where a back-off timer associated with a data network name (DNN) based congestion control is running;
overriding the back-off timer which is running when the attach request message includes information on a packet data unit (PDU) session which the UE uses in the first system; and
transmitting, to the UE, an accept message for the attach request message.

8. The method of claim 7 , further comprising:
performing a procedure for packet data network (PDN) connection creation for the corresponding PDU session based on the information on the PDU session.

9. The method of claim 7 , wherein the information on the PDU session includes identification information for one or more PDU sessions used in the first system.

10. The method of claim 7 , wherein the information on the PDU session is included in an information element field in the attach request message.

11. The method of claim 7 , wherein the information on the PDU session is included in a protocol configuration option (PCO) in a session management (SM) container in the attach request message.

12. The method of claim 7 , wherein the first network is a 5th generation system (5GS) and the second network is an evolved packet system (EPS).

13. A user equipment (UE) for performing an attach request procedure, the UE comprising:
a transceiver; and
a processor including the transceiver,
wherein the processor performs
a process of transmitting an attach request message to a second system when an intersystem change from a first system to the second system is required in a state where a back-off timer associated with a data network name (DNN) based congestion control is running,
wherein the attach request message includes information on a packet data unit (PDU) session used by the UE in the first system, and
wherein the information on the PDU session is used so as not for the attach request message to be rejected by a second network, even if the back-off timer associated with the DNN-based congestion control is running.

14. A mobility management entity (MME) for performing an attach request procedure, the MME comprising:
a transceiver; and
a processor controlling the transceiver,
wherein the processor performs
receiving an attach request message from user equipment (UE) which requires an intersystem change from a first system to a second system in a state where a back-off timer associated with a data network name (DNN) based congestion control is running,
overriding the back-off timer which is running when the attach request message includes information on a packet data unit (PDU) session which the UE uses in the first system, and
transmitting, to the UE, an accept message for the attach request message.

Assignees

• Lg Electronics Inc

Inventors

• Park Sangmin
• Kim Laeyoung
• Kim Taehun
• Kim Jaehyun
• Ryu Jinsook
• Youn Myungjune

Classifications

• H04W28/0289

  Congestion control (load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12) · CPC title

• H04W88/06

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W60/04

  using triggered events · CPC title

• H04W92/02

  Inter-networking arrangements · CPC title

• H04W28/0226 Primary

  based on location or mobility (handoff or reselection H04W36/00; mobile application services making use of the location of users or terminals H04W4/02) · CPC title