Radio link failure handling for dual connectivity

• US 10,397,935 B2
• Filed: 06/07/2018
• Issued: 08/27/2019
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Heo, Youn Hyoung, Zhang, Yujian
• Primary Examiner(s): O Connor, Brian T
• Application Number:
  US16/003,019
• Publication Number:
  US 20180288778A1
• Time in Patent Office: 446 Days
• CPC Class Codes: H04B 17/17 Detection of non-compliance or faulty performance, e.g. response deviations H04B17/18 takes precedence
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/0215 based on user or device properties, e.g. MTC-capable devices services for machine-to-machine communication [M2M] or machine type communication [MTC] H04W4/70; wireless resource selection or allocation plan definition based on terminal or device properties H04W72/51
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/50 Service provisioning or reconfiguring
• CPC Class Codes: H04W 4/60 Subscription-based services using application servers or record carriers, e.g. SIM application toolkits
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/06 based on traffic conditions
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/18 : Selecting a network or a communication service
• CPC Class Codes: H04W 52/346 : distributing total power among users or channels
• CPC Class Codes: H04W 56/001 : Synchronization between nodes
• CPC Class Codes: H04W 56/002 : Mutual synchronization
• CPC Class Codes: H04W 60/00 : Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 60/02 : by periodical registration
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/51 : based on terminal or device properties
• CPC Class Codes: H04W 72/52 : based on load
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: H04W 72/56 : based on priority criteria
• CPC Class Codes: H04W 74/004 : in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/0833 : Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/14 : Direct-mode setup
• CPC Class Codes: H04W 76/15 : Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/18 : Management of setup rejection or failure
• CPC Class Codes: H04W 76/19 : Connection re-establishment
• CPC Class Codes: H04W 8/005 : Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/06 : Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/183 : Processing at user equipment or user record carrier
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: H04W 88/16 : Gateway arrangements
• CPC Class Codes: H04W 88/18 : Service support devices; Network management devices
• CPC Class Codes: H04W 92/20 : between access points
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Embodiments of an evolved Node B (eNB) and methods for radio link failure handling for dual connectivity are generally described herein. A method performed by circuitry of a User Equipment (UE) may include connecting at a UE, to a Master eNB (MeNB) and connecting to a Secondary eNB (SeNB). The method may include determining at the UE, that one of the connections has a Radio Link Failure and determining at the UE, that the other of the connections remains connected to the UE. The method may include refraining from initiating a Radio Resource Control (RRC) re-establishment procedure while at least one of the connections does not have a radio link failure.

Claims

1. An apparatus of a user equipment (UE), the apparatus configured to transmit and receive communications with a Master evolved Node-B (MeNB) and a Secondary evolved Node-B (SeNB) when in a dual connectivity (DC) configuration, the apparatus comprising:

processing circuitry, the processing circuitry configured to;

detect a radio link failure (RLF) for the SeNB;

encode for transmission to the MeNB, a radio resource control (RRC) indication that the connection with the SeNB has experienced RLF;

release a serving cell configuration of the SeNB in response to a request from the MeNB, upon determining the connection with the SeNB has experienced the RLF; and

maintain connection with radio bearers for the MeNB in a non-DC configuration, after release of the serving cell configuration of the SeNB; and

memory coupled to the processing circuitry, the memory configured to store the RRC indication.

2. The apparatus of claim 1, wherein the processing circuitry is further configured to:

suspend radio bearers for the SeNB based on the detected RLF for the SeNB; and

reset a media access control (MAC) layer associated with communications with the SeNB.

3. The apparatus of claim 2, wherein the radio bearers for the SeNB include a data radio bearer (DRB).

4. The apparatus of claim 2, wherein the radio bearers for the SeNB include a split DRB.

5. The apparatus of claim 1, wherein the processing circuitry is configured to:

determine the connection with the SeNB has the RLF based on an expiration of an out-of-sync timer indicating lack of synchronization with the SeNB.

6. The apparatus of claim 1, wherein the processing circuitry is configured to:

determine the connection with the SeNB has the RLF based on a random access problem indication received from a media access control (MAC) layer.

7. The apparatus of claim 1, wherein the processing circuitry is configured to:

decode an indication from a radio link control (RLC) layer of the SeNB that a maximum number of retransmissions has been reached for a secondary cell group (SCG) of the SeNB; and

determine a connection with the SeNB has the RLF based on the decoded indication.

8. The apparatus of claim 1, wherein the processing circuitry is configured to:

refrain from initiating a radio resource control (RRC) re-establishment procedure between the UE and the SeNB while a connection between the UE and the MeNB does not have an RLF.

9. The apparatus of claim 1, wherein the processing circuitry is configured to:

upon detecting the RLF with the SeNB, apply one of the following;

a default physical channel configuration or a default semi-persistent scheduling configuration to maintain a connection with the MeNB.

10. The apparatus of claim 1, wherein the processing circuitry is configured to:

reconfigure at least one radio bearer served by the SeNB in response to the request from the MeNB.

11. An apparatus of a first evolved Node-B (eNB), the apparatus comprising processing circuitry coupled to memory, the processing circuitry configured to:

decode a radio resource control (RRC) indication from a user equipment (UE) that a connection between the UE and a second eNB has experienced a radio link failure (RLF), the UE in a dual connectivity state with the first eNB and the second eNB; and

encode a configuration message for transmission to the UE, to release a secondary cell group of the second eNB and suspend at least one radio bearer, the at least one radio bearer used prior to being suspended by the second eNB to communicate with the UE.

12. The apparatus of claim 11, wherein the at least one radio bearer is one of a data radio bearer (DRB) or a split DRB.

13. The apparatus of claim 11, wherein the first eNB is a Master eNB (MeNB) and the second eNB is a Secondary eNB (SeNB), and wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell).

14. The apparatus of claim 13, wherein operations to suspend the at least one radio bearer used by the second eNB include operations to suspend all radio bearers used by the SeNB.

15. An apparatus of a user equipment (UE), the apparatus comprising:

processing circuitry coupled to memory, the processing circuitry configured to;

detect a radio link failure (RLF) for a Secondary evolved Node-B (SeNB), while the UE is in a dual connectivity (DC) state with the SeNB and a Master evolved Node-B (MeNB), wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell); and

upon detecting the RLF;

encode for transmission to the MeNB, a radio resource control (RRC) indication that the connection with the SeNB has experienced RLF;

decode a Radio Resource Control reconfiguration message from the MeNB to remove the SCell from a set of cells serving the UE; and

maintain connection with radio bearers for the MeNB in a non-DC configuration, after release of a serving cell configuration of the SeNB.

16. The apparatus of claim 15, wherein the processing circuitry is configured to:

suspend radio bearers for the SeNB, wherein the radio bearers for the SeNB include a data radio bearer (DRB) or a split DRB; and

reset a media access control (MAC) layer associated with communications with the SeNB.

17. The apparatus of claim 15, wherein the processing circuitry is configured to:

determine the connection with the SeNB has the RLF based on an expiration of an out-of-sync timer indicating lack of synchronization with the SeNB.

18. The apparatus of claim 15, wherein the processing circuitry is configured to:

determine the connection with the SeNB has the RLF based on a random access problem indication received from the MAC layer associated with communications to the SeNB.

19. The apparatus of claim 15, wherein the processing circuitry is configured to:

decode an indication from a radio link control (RLC) layer of the SeNB that a maximum number of retransmissions has been reached for the SCell of the SeNB; and

determine a connection with the SeNB has the RLF based on the decoded indication.

20. A non-transitory computer readable storage device including instructions stored thereon, which when executed by one or more processors of a User Equipment (UE), cause the UE to perform operations to:

detect a radio link failure (RLF) for a Secondary evolved Node-B (SeNB), while the UE is in a dual connectivity (DC) state with a secondary cell (SCell) of the SeNB and a primary cell (PCell) of a Master evolved Node-B (MeNB);

encode for transmission to the MeNB, a radio resource control (RRC) indication that the connection with the SeNB has experienced RLF;

release a serving cell configuration of the SeNB in response to a request from the MeNB, upon determining the connection with the SeNB has experienced the RLF; and

maintain connection with radio bearers for the MeNB in a non-DC configuration, after release of the serving cell configuration of the SeNB.

21. The non-transitory computer readable storage device of claim 20, wherein the instructions further cause the UE to perform operations to:

determine the connection with the SeNB has the RLF based on an expiration of an out-of-sync timer indicating lack of synchronization with the SeNB.

22. The non-transitory computer readable storage device of claim 20, wherein the instructions further cause the UE to perform operations to:

suspend radio bearers for the SeNB, wherein the radio bearers for the SeNB include a data radio bearer (DRB) or a split DRB; and

reset a media access control (MAC) layer associated with communications to the SeNB.