Signaling Method To Enable Controlled TX Deferring In Mixed License and Unlicensed Spectrum In Carrier Aggregation In Future LTE-A Networks

• US 20140036818A1
• Filed: 08/09/2013
• Published: 02/06/2014
• Est. Priority Date: 02/11/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Renesas Mobile Corporation (Renesas Electronics Corporation)
• Inventors: KOSKELA, Timo, HAKOLA, Sami Jukka, TURTINEN, Samuli, GAO, Chunyan
• Granted Patent: US 9,258,811 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

The present invention discloses a signaling method, an apparatus and a computer program for controlled transmission signal deferring utilizing both licensed and unlicensed frequency bands for carrier aggregation. In the method, a connection is established between a User Equipment and a base station. For example, based on a sensed interference level, a transmission deferring indication is generated regarding a secondary component carrier locating on an unlicensed band, in case the secondary component carrier is occupied. This indication may be generated and sent either by the base station or by the User Equipment. Finally, the secondary component carrier is deactivated for data transmission, for deferring data transmission for a certain time period. After the deferring time has passed, the data transmission can be re-performed on the same secondary component carrier, or through switching to another secondary component carrier in unlicensed spectrum.

Claims

1. A method, comprising:

establishing a connection between a User Equipment (UE) and a base station (eNB) utilizing licensed and unlicensed frequency bands;

generating a transmission deferring indication regarding a first component carrier locating on an unlicensed band, in case the first component carrier is occupied; and

deactivating data transmission on the first component carrier according to the transmission deferring indication for deferring the data transmission on the first component carrier.

2. The method according to claim 1, further comprising:

transmitting deferred data on a second component carrier after a deferring time has passed.

3. The method according to claim 1, wherein the transmission deferring indication is triggered by noticed interference exceeding a predetermined threshold on the first component carrier.

4. The method according to claim 1, wherein the transmission deferring indication is User Equipment specific or component carrier specific.

5. The method according to claim 2, wherein the second component carrier is the same as the first component carrier, the component carrier becoming unoccupied during the deferring time.

6. The method according to claim 1, wherein the transmission deferring indication is sent by the base station (eNB) via Physical Downlink Control Channel (PDCCH).

7. The method according to claim 1, further comprising:

starting a timer for a Hybrid Automatic Repeat Request (HARQ) process for uplink data transmission; and

in case the base station (eNB) does not schedule a data transmission for the deferred HARQ process before the timer expires;

flushing a HARQ buffer; and

indicating data transmission as failed.

8. The method according to claim 1, wherein the User Equipment (UE) decides whether the first component carrier locating on an unlicensed band is occupied, by sensing available resources on an uplink transmission.

9. The method according to claim 8, wherein the transmission deferring indication is sent via physical uplink shared channel (PUSCH) of a primary component carrier (PCC) using a licensed frequency band, and where the first component carrier is a secondary component carrier (SCC).

10. The method according to claim 3, further comprising:

lowering a modulation and coding scheme (MCS) because of the noticed interference in the User Equipment (UE); and

including a lowered MCS information in the transmission deferring indication sent to the base station (eNB).

11. The method according to claim 2, further comprising:

scheduling deferred data transmission onto other carrier via new Downlink Control Information (DCI) format using the PDCCH.

12. The method according to claim 1, wherein the User Equipment (UE) indicates via Physical Uplink Control Channel (PUCCH) whether the User Equipment (UE) is transmitting on the licensed frequency band.

13. The method according to claim 1, further comprising:

marking a component carrier as heavily occupied when recurrent transmission deferring indications have been generated; and

scheduling a non-heavily occupied component carrier for the data transmission.

14. The method according to claim 1, further comprising:

gathering information regarding the unlicensed frequency bands, comprising used and available resources on the bands, in the base station (eNB).

15. An apparatus, further comprising a processor configured to:

establish a connection between a User Equipment (UE) and a base station (eNB) utilizing licensed and unlicensed frequency bands;

generate and send either in downlink or uplink direction a transmission deferring indication regarding a first component carrier locating on an unlicensed band, in case the first component carrier is occupied; and

deactivate data transmission on the first component carrier, according to the transmission deferring indication for deferring the data transmission on the first component carrier.

16. The apparatus according to claim 15, wherein the processor is configured to send the transmission deferring indication on a primary component carrier (PCC) on the licensed frequency band while the first component carrier is a secondary component carrier (SCC).

17. The apparatus according to claim 15, wherein the apparatus is configured to sense interference on resources on an unlicensed band, and based on that, to trigger the transmission deferring indication.

18. The apparatus according to claim 15, wherein the transmission deferring indication covers the uplink data transmission by the User Equipment (UE).

19. The apparatus according to claim 15, wherein the transmission deferring indication covers all resources on the unlicensed spectrum or resources on the first component carrier only.

20. The apparatus according to claim 15, wherein the processor is configured to transmit the deferred data either on a second component carrier or on the first component carrier, depending on the occupying condition of resources on the first component carrier.

21. The apparatus according to claim 15, wherein the apparatus is implemented in the base station (eNB), and further, the processor is configured to send the transmission deferring indication via Physical Downlink Control Channel (PDCCH).

22. The apparatus according to claim 15, wherein the apparatus is implemented in the User Equipment (UE), and further, the processor is configured to send the transmission deferring indication via physical uplink shared channel (PUSCH) of a primary component carrier using a licensed frequency band.

23. A computer program comprising code adapted to perform the following steps, when executed on a data-processing system, comprising:

establishing a connection between a User Equipment (UE) and a base station (eNB) utilizing licensed and unlicensed frequency bands;

generating a transmission deferring indication regarding a first component carrier locating on an unlicensed band, in case the first component carrier is occupied; and

deactivating data transmission on the first component carrier according to the transmission deferring indication for deferring the data transmission on the first component carrier.

24. The computer program according to claim 23, wherein the computer program is stored on a computer readable medium.