Periodic Timer Synchronization Logic For RRC Inactive State

Patent metadata

Field	Value
Publication number	US-2018317194-A1
Application number	US-201816030540-A
Country	US
Kind code	A1
Filing date	Jul 9, 2018
Priority date	Mar 24, 2017
Publication date	Nov 1, 2018
Grant date	—

Abstract

A method performed by an AMF is provided. The method includes determining an elapsed time value (δRAN). The method further includes determining whether the elapsed time value is less than a negotiated NAS periodic timer (τNAS-per). The AMF is configured such that, as a result of the AMF determining that δRAN<τNAS-per, the AMF transitions the UE to CM-IDLE state and starts a NAS periodic timer with a value equal to τNAS-per−δRAN.

First claim

1 . A method performed by an access and mobility management function (AMF), the method comprising:
determining an elapsed time value (δ RAN ); and determining whether the elapsed time value (δ RAN ) is less than a negotiated NAS periodic timer (τ NAS-per ), wherein the AMF is configured such that, as a result of the AMF determining that δ RAN <τ NAS-per , the AMF transitions a user equipment (UE) to CM-IDLE state and starts a NAS periodic timer with a value equal to τ NAS-per −δ RAN .

2 . The method of claim 1 , wherein the AMF is further configured such that as a result of the AMF determining that τ NAS-per ≤δ RAN , the AMF transitions the UE to CM-IDLE state and clears a Paging Proceed Flag (PPF) associated with the UE.

3 . The method of claim 2 , wherein the AMF is further configured such that as a result of the AMF determining that τ NAS-per ≤δ RAN and δ RAN <τ NAS-per +τ det , the AMF starts a NAS periodic timer at a value equal to τ det −(δ RAN −τ NAS-per ), wherein τ det is a NAS implicit detach timer.

4 . The method of claim 2 , wherein the AMF is further configured such that as a result of the AMF determining that δ RAN >τ NAS-per +τ det , the AMF implicitly detaches the UE.

5 . The method of claim 1 , where determining the elapsed time value (δ RAN ) comprises receiving from an access network (AN) a user equipment (UE) context release request including an elapsed time value (δ RAN ).

6 . A method performed by an access and mobility management function (AMF), the method comprising:
receiving from an access network (AN), a N2 UE context release request associated with a UE and including an elapsed time value (δ RAN ) indicating the amount of time that elapsed between the AN starting a periodic timer for use in monitoring the UE and the AN transmitting the N2 UE context release request.

7 . The method of claim 6 , further comprising:
determining that a user equipment (UE) is ready to transition to a CM-CONNECTED, RRC-Active state; and in response to determining that the UE is ready to transition to a CM-CONNECTED, RRC-Active state, sending to an access network (AN) a UE context request including a NAS periodic timer and a NAS registration area.

8 . A method performed by an access network (AN) the method comprising:
determining that a user equipment (UE), has transitioned to CM-CONNECTED, RRC-Inactive state; in response to determining that the UE has transitioned to CM-CONNECTED, RRC-Inactive state, starting a periodic update timer; determining to remove a UE-RAN context associated with the UE; and in response to determining to remove the UE-RAN context associated with the UE, sending to an access and mobility management function (AMF) a N2 UE context release request including an elapsed time value (δ RAN ) of the periodic update timer.

9 . The method of claim 8 , further comprising:
sending to the AMF a UE context response comprising a periodic RAN update timer value indicating the period RAN update timer value that the RAN intends to configure the UE with.

10 . The method of claim 8 , further comprising notifying the AMF that the UE has entered into the RRC inactive state.

11 . A method performed by an access network (AN), the method comprising:
receiving from an access and mobility management function (AMF) a user equipment (UE) context request including a NAS periodic timer and a NAS registration area, indicating that a UE is ready to transition to a CM-CONNECTED, RRC-Active state; setting up an RRC connection between the UE and the AN; determining that the UE has transitioned to CM-CONNECTED, RRC-Inactive state; in response to determining that the UE has transitioned to CM-CONNECTED, RRC-Inactive state, starting a periodic update timer; determining to remove a UE-RAN context associated with the UE; and in response to determining to remove the UE-RAN context associated with the UE, sending to the AMF a N2 UE context release request including an elapsed time value (δ RAN ) of the periodic update timer.

12 . The method according to claim 11 , further comprising:
sending to the AMF a UE context response comprising a periodic RAN update timer value indicating the period RAN update timer value that the RAN intends to configure the UE with.

13 . The method according to claim 11 , further comprising notifying the AMF that the UE has entered into the RRC inactive state.

14 . An access and mobility management function (AMF) configured to perform the method of claim 1 , wherein the AMF comprises:
a receiver; a transmitter; a data storage system; and a data processing apparatus comprising a processor, wherein the data processing apparatus is coupled to the data storage system, the transmitter, and the receiver.

15 . The AMF of claim 14 , wherein the data processing apparatus is further configured to, as a result of determining that τ NAS-per ≤δ RAN , transition the UE to CM-IDLE state and clear a Paging Proceed Flag (PPF) associated with the UE.

16 . The AMF of claim 14 , wherein the data processing apparatus is further configured to, as a result of determining that τ NAS-per ≤δ RAN and δ RAN <τ NAS-per +τ det , start a NAS periodic timer at a value equal to τ det −(δ RAN −τ NAS-per ), wherein τ det is a NAS implicit detach timer.

17 . The AMF of claim 14 , wherein the data processing apparatus is further configured to, as a result of determining that δ RAN >τ NAS-per +τ det , implicitly detach the UE ( 102 ).

18 . An access network (AN) configured to perform the method of claim 11 , the AN comprising:
a receiver; a transmitter; a data storage system; and a data processing apparatus comprising a processor, wherein the data processing apparatus is coupled to the data storage system, the transmitter, and the receiver.

19 . The AN of claim 18 , wherein the data processing apparatus is further configured to send to the AMF a UE context response comprising a periodic RAN update timer value indicating the period RAN update timer value that the RAN intends to configure the UE with; and notify the AMF that the UE has entered into the RRC inactive state.

Assignees

• Chen Qian
• Karlsson Josefin
• Ramle Peter
• Schliwa Bertling Paul
• Ericsson Telefon Ab L M

Inventors

• Chen Qian
• Karlsson Josefin
• Ramle Peter
• Schliwa-Bertling Paul

Classifications

• H04W60/04 Primary

  using triggered events · CPC title

• H04W76/27 Primary

  Transitions between radio resource control [RRC] states · CPC title

• H04W64/00

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title

• H04W8/08

  Mobility data transfer · CPC title

• H04W52/0212

  managed by the network, e.g. network or access point is leader and terminal is follower · CPC title