Listen before talk (LBT) configuration for wireless communication in unlicensed frequency bands
View Patent ↗Apparatus, systems, and methods provide for transmitting a Sounding Reference Signal (SRS) or other reference signal over a cellular network operating on an unlicensed radio band. Specifically, an apparatus, such as a User Equipment (UE) or Base Station (eNB), determines one or more channel sensing metrics for a radio channel. Based on the channel sensing metrics, the apparatus then determines a Listen Before Talk (LBT) mode and/or a LBT sensing time. The UE then performs a LBT process using the LBT mode and the LBT sensing time. If the UE determines that the radio channel is not occupied, the UE transmits a signal, such as a control signal (e.g., a Sounding Reference Signal (SRS)), over the radio channel.
1. A method for determining Listen Before Talk (LBT) characteristics for operating on an unlicensed radio band of a cellular network, the method comprising:
determining one or more channel sensing metrics for a radio channel, wherein the one or more channel sensing metrics include at least a channel occupancy metric;
based on the one or more channel sensing metrics, determining (i) a LBT mode or (ii) a LBT sensing time;
performing a LBT process using at least one of (i) the LBT mode or (ii) the LBT sensing time determined; and
when allowed according to the LBT process, performing a transmission on the radio channel.
2. The method of claim 1 , wherein determining the one or more channel sensing metrics comprises determining a link quality metric.
3. The method of claim 1 , wherein the LBT sensing time comprises an initial Contention Window Size (CWS) or a fixed sensing time period.
4. The method of claim 1 , wherein determining (i) the LBT mode or (ii) the LBT sensing time comprises:
comparing a first channel sensing metric of the one or more channel sensing metrics to a threshold value; and
based on comparing the first channel sensing metric to the threshold value, determining the LBT mode.
5. The method of claim 1 , wherein the LBT mode requires a Contention Window (CW).
6. The method of claim 1 , wherein the LBT mode requires a fixed sensing time period.
7. The method of claim 1 , wherein determining (i) the LBT mode or (ii) the LBT sensing time comprises:
comparing a first channel sensing metric of the one or more channel sensing metrics to a threshold value; and
based on comparing the first channel sensing metric to the threshold value, determining the LBT sensing time.
8. The method of claim 1 , wherein:
determining the one or more channel sensing metrics comprises determining, by a Base Station (eNB), the one or more channel sensing metrics;
determining (i) the LBT mode or (ii) the LBT sensing time comprises determining, by the eNB, (i) the LBT mode or (ii) the LBT sensing time based on the one or more channel sensing metrics; and
the method comprises transmitting, by the eNB, (i) the LBT mode or (ii) the LBT sensing time to a User Equipment (UE).
9. The method of claim 8 , wherein:
determining (i) the LBT mode or (ii) the LBT sensing time comprises determining, by the eNB, (i) the LBT mode and (ii) the LBT sensing time based on the one or more channel sensing metrics; and
transmitting (i) the LBT mode or (ii) the LBT sensing time comprises transmitting, by the eNB, (i) the LBT mode and (ii) the LBT sensing time to a User Equipment (UE).
10. The method of claim 1 , comprising performing, by a User Equipment (UE), the LBT process using (i) the LBT mode and (ii) the LBT sensing time;
wherein determining the one or more channel sensing metrics comprises determining, by the UE, the one or more channel sensing metrics; and
wherein determining (i) the LBT mode or (ii) the LBT sensing time comprises determining, by the UE, (i) the LBT mode or (ii) the LBT sensing time based on the one or more channel sensing metrics.
11. The method of claim 10 , wherein determining (i) the LBT mode or (ii) the LBT sensing time comprises determining, by the UE, (i) the LBT mode and (ii) the LBT sensing time based on the one or more channel sensing metrics.
12. The method of claim 10 , comprising receiving, by the UE, the LBT mode from a Base Station (eNB);
wherein determining (i) the LBT mode or (ii) the LBT sensing time comprises determining, by the UE, the LBT sensing time based on the one or more channel sensing metrics.
13. The method of claim 10 , wherein performing the LBT process comprises transmitting, by the UE, a signal at a time within a contention window or after a fixed sensing time period.
14. The method of claim 13 , wherein the signal comprises a control signal.
15. An apparatus configured to operate on an unlicensed radio band of a cellular network, the apparatus comprising:
a computing platform having a memory and a processor device in communication with the memory; and
a control application stored in the memory, executable by the processor device, and configured for:
determining one or more channel sensing metrics for a radio channel, wherein the one or more channel sensing metrics include at least a channel occupancy metric;
based on the one or more channel sensing metrics, determining (i) a Listen Before Talk (LBT) mode or (ii) a LBT sensing time;
performing a LBT process using at least one of (i) the LBT mode or (ii) the LBT sensing time determined; and
when allowed according to the LBT process, performing a transmission on the radio channel.
16. The apparatus of claim 15 , wherein the apparatus is a Base Station (eNB).
17. The apparatus of claim 15 , wherein the apparatus is a User Equipment (UE).
18. A cellular communication network configured to operate on an unlicensed radio band, comprising:
a Base Station (eNB) apparatus, the eNB comprising a computing platform having a memory, a processor device in communication with the memory, and a control application stored in the memory, executable by the processor device, and configured for:
determining one or more first channel sensing metrics for a radio channel wherein the one or more first channel sensing metrics include at least a channel occupancy metric;
based on the one or more first channel sensing metrics, determining a Listen Before Talk (LBT) mode; and
transmitting the LBT mode to a User Equipment (UE); and
the UE, the UE comprising a second computing platform having a second memory, a second processor device in communication with the second memory, and a second control application stored in the second memory, executable by the second processor device, and configured for:
receiving the LBT mode from the eNB;
determining one or more second channel sensing metrics for the radio channel;
based on the one or more second channel sensing metrics, determining a LBT sensing time; and
performing a LBT process using (i) the LBT mode and (ii) the LBT sensing time.