Reducing latency in an unlicensed frequency spectrum

• US 10,292,137 B1
• Filed: 10/12/2016
• Issued: 05/14/2019
• Est. Priority Date: 10/12/2016
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Zappaterra, Luca, Zhou, Yu, Naim, Muhammad Ahsan
• Primary Examiner(s): Nguyen, Minh Trang T
• Application Number:
  US15/291,095
• Time in Patent Office: 944 Days
• Field of Search: None
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 1/0018 based on latency requirement
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Reducing latency in a wireless network includes initiating a sensing period for measuring signal indicators of a plurality of frequency channels of an unlicensed spectrum, determining that one of the plurality of frequency channels is able to sustain a traffic load, interrupting the sensing period, and scheduling one or more cellular subframes during the remainder of the sensing period using the one of the plurality of frequency channels.

Claims

1. A method for reducing latency in a wireless network, the method comprising:

measuring, during a sensing period, a first signal indicator of a first frequency channel deployed by an access node; and

scheduling one or more cellular subframes in the first frequency channel during the sensing period based upon the first signal indicator meeting a load threshold,

wherein the sensing period comprises an initial portion of a master frame.

2. The method of claim 1, further comprising measuring a second signal indicator of a second frequency channel during the sensing period based upon the first signal indicator not meeting the threshold.

3. The method of claim 2, further comprising scheduling the one or more cellular subframes using the second frequency channel during the sensing period based upon the second signal indicator meeting the threshold.

4. The method of claim 2, further comprising measuring a third signal indicator of a third frequency channel during the sensing period based upon the second signal indicator not meeting the threshold.

5. The method of claim 1, wherein scheduling the one or more cellular subframes comprises switching the first frequency channel from a first operating mode to a second operating mode, and scheduling the one or more cellular subframes using the second operating mode.

6. The method of claim 5, wherein:

the first operating mode comprises Wi-Fi,

the second operating mode comprises cellular data, and

the first frequency channel is a portion of an unlicensed frequency spectrum.

7. The method of claim 1, wherein the load threshold is based on a traffic load of the access node.

8. The method of claim 7, further comprising determining, based on the traffic load, a number of additional cellular subframes to be scheduled in the first frequency channel subsequent to the sensing period.

9. The method of claim 8, further comprising determining that a latency requirement of the traffic load meets a latency threshold, and scheduling one or more of the additional cellular subframes immediately after the sensing period.

10. The method of claim 1, wherein the one or more cellular subframes comprise any combination of downlink subframes or uplink subframes.

11. A system for scheduling resources in a wireless network, the system comprising:

an access node deploying a plurality of frequency channels using an unlicensed frequency band; and

a processor coupled to the access node, the processor for configuring the access node to perform operations comprising;

determining a traffic load of the access node;

for a defined time period, sequentially determining if each of the plurality of frequency channels is able to sustain the traffic load; and

upon determining that one of the plurality of frequency channels is able to sustain the traffic load, scheduling one or more cellular subframes in said one of the plurality of frequency channels prior to expiration of the defined time period.

12. The system of claim 11, wherein sequentially determining if each of the plurality of frequency channels is able to sustain the traffic load is based on a signal strength indicator of each of the plurality of frequency channels.

15. The system of claim 11, wherein the one or more cellular subframes is scheduled in said one of the plurality of frequency channels using a operating mode that is different from a default operating mode of said one of the plurality of frequency channels.

16. The system of claim 15, wherein the operations further comprise scheduling additional cellular subframes immediately subsequent to expiration of the defined time period.

17. The system of claim 15, wherein the operations further comprise switching to the default operating mode immediately subsequent to expiration of the defined time period.

13. The system of 12, wherein the operations further comprise determining a historical trend of signal strength indicators for each frequency channel.

14. The system of claim 13, wherein the sequential determination is performed in decreasing order of the historic trend of signal strength indicators.

18. A processing node for scheduling resources in a wireless network, the processing node being configured to perform operations comprising:

initiating a sensing period for measuring signal indicators of a plurality of frequency channels of an unlicensed spectrum;

determining that one of the plurality of frequency channels is able to sustain a traffic load; and

scheduling one or more cellular subframes during the sensing period using the one of the plurality of frequency channels.

19. The processing node of claim 18, wherein the traffic load is based on application requirements of one or more wireless devices, the application requirements further comprising a latency requirement.

20. The processing node of claim 19, wherein the operations further comprise scheduling additional downlink subframes immediately subsequent to expiration of the defined time period based on the latency requirement.