Radio link failure handling for dual connectivity

Patent metadata

Field	Value
Publication number	US-9674852-B2
Application number	US-201414491639-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Oct 31, 2013
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

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.

First claim

What is claimed is:

1. A first evolved Node B (eNB), the first eNB connected to a User Equipment (UE), the first eNB comprising:
hardware processing circuitry arranged to:
receive, from the UE, an indication of a Radio Link Failure at a second eNB, the UE in a dual connectivity state with the first eNB and the second eNB, wherein the indication indicates that the UE is to refrain from initiating a Radio Resource Control (RRC) re-establishment procedure between the UE and the second eNB; and
communicate to the second eNB a command to 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.

2. The first eNB of claim 1 , 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).

3. The first eNB of claim 2 , 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.

4. The first eNB of claim 2 , wherein the hardware processing circuitry of the MeNB is further arranged to transmit a Radio Resource Control reconfiguration message to the UE to remove the SCell from a set of cells serving the UE.

5. The first eNB of claim 1 , wherein the first eNB is a Secondary eNB (SeNB) and the second eNB is a Master eNB (MeNB), and wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell).

6. The first eNB of claim 5 , wherein operations to suspend at least one radio bearer used by the second eNB include operations to suspend a Signaling Radio Bearer 1 (SRB 1 ) and a Signaling Radio Bearer 2 (SRB 2 ) used by the MeNB.

7. The first eNB of claim 5 , wherein the hardware processing circuitry of the SeNB is further arranged to relay a Radio Resource Control reconfiguration message from the MeNB to the UE to suspend the at, least one radio bearer.

8. The first eNB of claim 5 , wherein the hardware processing circuitry of the SeNB is further arranged to receive instructions to initiate a handover from the MeNB to suspend the at least one radio bearer.

9. The first eNB of claim 5 , wherein the hardware processing circuitry of the SeNB is further arranged to use a UE context for the UE, the UE context maintained by the MeNB.

10. The first eNB of claim 5 , wherein the hardware processing circuitry of the SeNB is further arranged to receive the Radio Link Failure indication over a logical channel.

11. The first eNB of claim 5 , wherein the MeNB is further arranged to receive an indication of a random access problem from the UE.

12. The first eNB of claim 11 , wherein the indication is received by the MeNB using a Radio Resource Control (RRC) message.

13. The first eNB of claim 11 , wherein the indication is received by the MeNB using a MAC control element, and wherein the MAC control element has zero bytes or the MAC control element includes information indicating:
a random access problem in the SeNB, a radio link control error in the SeNB, or a radio link monitoring error in the SeNB.

14. User Equipment (UE) adapted for communication with an evolved Node B (eNB), the UE comprising:
a transceiver arranged to transmit and receive communication with a Master eNB (MeNB) and a Secondary eNB (SeNB) in a dual connectivity state; and
a processor, coupled to the transceiver, arranged to:
determine that one of a connection to the MeNB and a connection SeNB has a Radio Link Failure;
determine that the other one of the connection to the MeNB and the connection to the SeNB does not have a Radio Link Failure; and
prevent initiation, by the UE, of a Radio Resource Control (RRC) re-establishment procedure between the UE and the one of the connection to the MeNB and the connection to the SeNB that has the Radio Link Failure while the other one of the connection to the MeNB and the connection to the SeNB does not have a Radio Link Failure and remains connected to the UE.

15. The UE of claim 14 , wherein the connection that has a Radio Link Failure is the MeNB and the connection that remains connected is the SeNB, and wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell), and wherein the UE is further arranged to transmit a Radio Resource Control (RRC) message to the MeNB indicating that the SeNB has a Radio Link Failure.

16. The UE of claim 14 , wherein the connection that has a Radio Link Failure is the SeNB and the connection that remains connected is the MeNB, and wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell).

17. The UE of claim 16 , wherein the UE is further arranged to receive a Radio Resource Control reconfiguration message originating from the MeNB sent through the SeNB.

18. The UE of claim 16 , wherein the UE is further arranged to receive a handover command message originating from the MeNB through the SeNB.

19. The UE of claim 16 , wherein the UE is further arranged to receive a handover command message originating from the MeNB through a new cell, wherein the new cell is not the PCell or the SCell.

20. The UE of claim 16 , wherein the UE is further arranged to reconnect to the MeNB when a MeNB channel condition exceeds a threshold.

21. At least one non-transitory machine-readable medium including instructions for operation of a computing system, which when executed by a machine, cause the machine to:
connect, at a User Equipment (UE), to a Master evolved Node B (MeNB);
connect, at the UE, to a Secondary eNB (SeNB), in a dual connectivity state;
determine, at the UE, that one of the connections has a Radio Link Failure;
determine, at the UE, that the other of the connections does not have a Radio Link Failure; and
refrain, at the UE, from initiating a Radio Resource Control (RRC) re-establishment procedure between the UE and the one of the connections that has the Radio Link Failure while the other of the connections does not have a Radio Link Failure and remains connected to the UE.

22. The at least one machine-readable medium of claim 21 , wherein the connection that has a Radio Link Failure is the SeNB and the connection that remains connected is the MeNB, and wherein the MeNB is associated with a Primary Cell (PCell) and the SeNB is associated with a Secondary Cell (SCell).

23. The at least one machine-readable medium of claim 22 , further comprising, operations to receive, at the UE, a Radio Resource Control (RRC) reconfiguration message originating from the MeNB sent through the SeNB.

24. User Equipment (UE) adapted for communication with an evolved Node B (eNB), the UE comprising:
a transceiver arranged o transmit and receive communication with a Master eNB (MeNB) and a Secondary eNB (SeNB), in a dual connectivity state; and
a processor, coupled to the transceiver, arranged to perform operations in connection with a connection to a .MeNB and a connection. to a SeNB:
determine that one of a connection to the MeNB and a connection to the SeNB has a Radio Link Failure;
determine that the other one of the connection to the MeNB and the connection to the SeNB does not have a Radio Link Failure; and
communicate indirectly to the one of the connection to the MeNB and the connection to the SeNB to suspend at least one radio bearer used by the one o

Assignees

• Intel Ip Corp

Inventors

• Heo Youn Hyoung
• Zhang Yujian

Classifications

• H04W72/51

  based on terminal or device properties · CPC title

• H04W72/52

  based on load · CPC title

• H04W72/542

  using measured or perceived quality · CPC title

• H04W72/56 Primary

  based on priority criteria · CPC title

• H04W36/305

  Handover due to radio link failure (control signalling for hand-off failure H04W36/0079) · CPC title