RADIO TERMINAL, RADIO STATION, AND METHOD THEREOF

• US 20170318473A1
• Filed: 10/09/2015
• Published: 11/02/2017
• Est. Priority Date: 11/06/2014
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: FUTAKI, Hisashi
• Granted Patent: US 10,306,478 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/04 Wireless resource allocation

Abstract

A radio terminal (3) operates to perform a predetermined process regarding a first cell (Cell #2) on an unlicensed frequency (F2) based on a predetermined relationship between a frame timing of a first serving cell (Cell #1) using a licensed frequency (F1) and a frame timing of the first cell (Cell #2) using the unlicensed frequency (F2). This contributes, for example, to enabling a radio terminal to differentiate among two or more cells when these cells use the same cell identifier.

Claims

1. A radio terminal comprising:

a memory; and

at least one processor coupled to the memory and configured to perform a predetermined process regarding a first cell on an unlicensed frequency based on a predetermined relationship between a frame timing of a first serving cell using a licensed frequency and a frame timing of the first cell using the unlicensed frequency.

2. The radio terminal according to claim 1, wherein the predetermined relationship includes a relationship such that the frame timing of the first cell is aligned with the frame timing of the first serving cell.

3. The radio terminal according to claim 1, wherein the predetermined relationship includes a relationship such that the frame timing of the first cell is within a first offset from the frame timing of the first serving cell or the frame timing of the first cell is not within the first offset.

4. The radio terminal according to claim 3, wherein the at least one processor is configured to attempt to detect a cell on the unlicensed frequency and to determine whether a frame timing of the detected cell has the predetermined relationship with the frame timing of the first serving cell in order to determine whether the detected cell is to be subjected to the predetermined

5. The radio terminal according to claim 3, wherein the at least one processor is further configured to receive a set value of the first offset from a radio station of the first serving cell or from a radio station of a second serving cell different from the first serving cell.

6. The radio terminal according to claim 1, wherein the predetermined relationship includes a relationship such that the frame timing of the first cell is shifted from the frame timing of the first serving cell by a second offset.

7. The radio terminal according to claim 6, wherein the at least one processor is further configured to receive a set value of the second offset from a radio station of the first serving cell or from a radio station of a second serving cell different from the first serving cell.

8. The radio terminal according to claim 1, wherein the at least one processor is further configured to exclude, from being subjected to the predetermined process, a second cell that uses the unlicensed frequency and whose frame timing does not have the predetermined relationship with the frame timing of the first serving cell.

9. The radio terminal according to claim 1, wherein the at least one processor is configured to attempt to detect, on the unlicensed frequency, a second cell whose frame timing does not have the predetermined relationship with the frame timing of the first serving cell.

10. The radio terminal according to claim 9, wherein the second cell is a cell that is assigned with the same cell identifier as the first cell but that the radio terminal is not allowed to belong to.

11. The radio terminal according to claim 9, wherein the at least one processor is further configured to report detection of the second cell to a radio station of the first serving cell or to a radio station of a second serving cell different from the first serving cell.

12. The radio terminal according to claim 1, wherein the at least one processor is configured to, based on the predetermined relationship, differentiate the first cell from a second cell that uses the same cell identifier as the first cell but that the radio terminal is not allowed to belong to.

13. The radio terminal according to claim 1, wherein the predetermined process includes at least one of cell search, cell selection, cell reselection, detection of proximity to a cell, reporting of proximity to a cell, terminal measurement, reporting of a terminal measurement result, radio quality measurement, reporting of a radio quality measurement result, channel state measurement, reporting of a channel state measurement result, and sensing.

14. The radio terminal according to claim 1, wherein the at least one processor is configured to attempt to detect a cell on the unlicensed frequency and transmit, to a radio station of the first serving cell or to a radio station of a second serving cell different from the first serving cell, timing information regarding a frame timing of the detected cell and a cell identifier of the detected cell.

15. The radio terminal according to claim 14, wherein the timing information indicates a relationship between the frame timing of the detected cell and the frame timing of the first serving cell.

16. The radio terminal according to claim 14, wherein the timing information indicates a difference between the frame timing of the detected cell and the frame timing of the first serving cell.

17. The radio terminal according to claim 1, wherein the frame timing is (a) a time when the radio terminal receives a beginning of a radio frame or a subframe, (b) a time when one or a plurality of radio stations transmits the beginning of the radio frame or the subframe (c) a time when the radio station receives a synchronization signal, or (d) a time when one or a plurality of radio stations transmits the synchronization signal.

18. (canceled)

19. A radio station comprising:

a memory; and

at least one processor coupled to the memory, wherein

the at least one processor is configured to;

transmit, to a radio terminal, configuration information containing information regarding an offset between a frame timing of a first cell operated by the radio station on a licensed frequency and a frame timing of a second cell operated by the radio station on an unlicensed frequency; and

transmit, to the radio terminal, control information regarding a predetermined process performed by the radio terminal on the unlicensed frequency.

20. The radio station according to claim 19, wherein the information regarding the offset is used by the radio terminal to perform determination whether the second cell is to be subjected to the predetermined process.

21-23. -23. (canceled)

24. A method performed by a radio terminal comprising:

performing a predetermined process regarding a first cell on an unlicensed frequency based on a predetermined relationship between a frame timing of a first serving cell using a licensed frequency and a frame timing of the first cell using the unlicensed frequency.

25-46. -46. (canceled)