WIFI-coordinated LAA-LTE

• US 9,907,085 B2
• Filed: 09/23/2015
• Issued: 02/27/2018
• Est. Priority Date: 09/26/2014
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Li, Yong, Drory, Guy, Cohen, Yonatan, Yang, Baoguo, Fischer, Matthew, Levy, Sharon, Verma, Sindhu, Adhikari, Shubhodeep
• Primary Examiner(s): Pham, Chi H
• Assistant Examiner(s): Agureyev, Vladislav
• Application Number:
  US14/862,838
• Publication Number:
  US 20160095110A1
• Time in Patent Office: 888 Days
• Field of Search: None
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A method includes detecting, using a WiFi access point, channel use data indicating traffic on a plurality of channels of an unlicensed LTE band in a wireless network. The method further includes providing the channel use data to a Long Term Evolution (LTE) access point. The method further includes selecting, using the LTE access point, a channel for use in transmitting data by the LTE access point from among the plurality of channels based on the channel use data from the WiFi access point. The method further includes providing, from the LTE access point, an indication of an upcoming transmission configured to transmit data on the channel to the WiFi access point. The method further includes broadcasting one or more messages from the WiFi access point to one or more WiFi nodes, the one or more messages configured to prevent the WiFi nodes from transmitting on the channel.

Claims

1. A method, comprising:

determining, by a WiFi access point of a small cell, channel use data indicating traffic on a plurality of channels of an unlicensed Long Term Evolution (LTE) band in a wireless network;

transmitting, by the WiFi access point, the channel use data to a LTE access point of the small cell;

receiving, at the LTE access point, the channel use data from the WiFi access point;

selecting, using the LTE access point, a channel for use in transmitting data by the LTE access point from among the plurality of channels using the received channel use data from the WiFi access point;

at a second time prior to a first time, determining, by the WiFi access point, whether the channel is available for the LTE access point to transmit the data for a duration after the first time;

in response to determining the channel is available, reserving, by the WiFi access point, the channel for transmission for the duration after the first time; and

transmitting, by the LTE access point, the data during a transmission window between the first time and an end of the duration; and

providing, from the LTE access point to the WiFi access point, an indication of an upcoming transmission on the selected channel of the unlicensed LTE band.

2. The method of claim 1, the step of selecting the channel comprising selecting a first channel for which the channel use data indicates a lower level of traffic than one or more second channels reflected in the channel use data.

3. The method of claim 1, further comprising broadcasting one or more messages from the WiFi access point to one or more WiFi nodes, the one or more messages configured to prevent the WiFi nodes from transmitting on the channel.

4. The method of claim 3, wherein the indication of an upcoming transmission comprises the duration, and wherein the one or more messages comprise one or more clear-to-send messages configured to prevent the WiFi nodes from transmitting on the channel for at least the transmission duration.

5. The method of claim 4, wherein a first message of the one or more messages is directed to a recipient node of the transmission, and wherein the first message is configured to cause the recipient node to transmit a second message to one or more second WiFi nodes outside of a range of the WiFi access point configured to prevent the one or more second nodes from transmitting on the channel.

6. The method of claim 4, wherein the indication comprises a quality of service priority parameter for the transmission, and wherein the method further comprises, by the WiFi access point, adding a request associated with the indication to a queue with a plurality of other requests, each having one of a plurality of quality of service priority parameters, and prioritizing use of the channels among the request and the plurality of other requests using the plurality of quality of service priority parameters.

7. A method comprising:

determining, at a Long Term Evolution (LTE) access point of a small cell configured to transmit data over an unlicensed LTE band, a first transmission window in which to transmit data to one or more devices over a channel of the unlicensed LTE band beginning at a first time, wherein the LTE access point shares the channel with a WiFi access point of the small cell, wherein the channel is selected by;

determining, by the WiFi access point, channel use data indicating traffic on a plurality of channels of the unlicensed LTE band;

transmitting, by the WiFi access point, the channel use data to the LTE access point;

receiving, at the LTE access point, the channel use data from the WiFi access point;

selecting, using the LTE access point, the channel using the received channel use data from the WiFi access point;

at a second time prior to the first time, determining, by the WiFi access point, whether the channel is available for the LTE access point to transmit the data for a duration after the first time based on a channel assessment;

in response to determining the channel is available, reserving, by the WiFi access point, the channel for transmission for the duration after the first time; and

transmitting, by the LTE access point, the data during the first transmission window between the first time and an end of the duration.

8. The method of claim 7, further comprising:

determining whether a remaining time within the first transmission window after transmission of the data is complete exceeds a threshold; and

cancelling reservation of the remaining time of the first transmission window in response to determining that the remaining time exceeds the threshold.

9. The method of claim 7, further comprising:

determining a timeframe between a third time at which the channel assessment is completed and the first time; and

reserving the channel for transmission for the duration after the first time in response to determining the timeframe exceeds a threshold timeframe.

11. The method of claim 7, further comprising:

determining whether the channel assessment will be complete by the first time; and

if the channel assessment will not be complete by the first time;

proceeding with transmitting the data during the first transmission window starting at the first time regardless of whether the channel assessment is complete;

waiting for the channel assessment to complete, reserving the channel for transmission after completion of the channel assessment, and transmitting the data within the first transmission window beginning at a third time after the first time;

or

skipping the first transmission window and attempting transmission of the data in a subsequent transmission window.

14. The method of claim 7, further comprising:

synchronizing the start of the first transmission window with the start of a WiFi transmission window of a WiFi access point beginning at the first time;

transmitting, at the second time, a channel reservation signal configured to reserve the channel for transmission starting at the first time; and

transmitting a filler signal after the channel reservation signal configured to prevent one or more WiFi devices from transmitting on the channel before transmission by the LTE access point, the filler signal transmitted for at least a portion of a timeframe between an end of transmission of the channel reservation signal and the first time.

15. The method of claim 7, further comprising:

determining whether a second frequency channel is available for transmission by the LTE access point during a second transmission window after the first transmission window; and

in response to determining the second frequency channel is available, transmitting a channel reservation signal configured to reserve the second frequency channel for transmission after transmission in the first transmission window.

16. The method of claim 7, further comprising determining at least one of a set of frequency channels over which to transmit data and a burst time per frequency channel based on one or more of:

a number of devices transmitting data on the set of frequency channels;

a total data load on the set of frequency channels;

or

an amount of data transmitted by the LTE access point and one or more other LTE access points on the set of frequency channels.

10. A method comprising:

determining, at a Long Term Evolution (LTE) access point configured to transmit data over an unlicensed LTE band, a first transmission window in which to transmit data to one or more devices over a channel of the unlicensed LTE band beginning at a first time;

at a second time prior to the first time, determining whether the channel is available for transmission of the data for a duration after the first time based on a channel assessment in response to determining the channel is available, reserving the channel for transmission for the duration after the first time;

determining a timeframe between a third time at which the channel assessment is completed and the first time; and

transmitting the data during the first transmission window between the first time and an end of the duration, wherein transmitting the data during the first transmission window comprises transmitting the data without reserving the channel for transmission in response to determining the timeframe is less than a threshold timeframe.

12. A method comprising:

determining, at a Long Term Evolution (LTE) access point configured to transmit data over an unlicensed LTE band, a first transmission window in which to transmit data to one or more devices over a channel of the unlicensed LTE band beginning at a first time;

at a second time prior to the first time, determining whether the channel is available for transmission of the data for a duration after the first time based on a channel assessment;

in response to determining the channel is available, reserving the channel for transmission for the duration after the first time; and

transmitting the data during the first transmission window between the first time and an end of the duration;

detecting channel characteristics of the channel;

activating a first mode of the LTE access point in which the LTE access point coordinates one or more LTE transmissions and one or more WiFi transmissions on the channel, the first mode activated in response to detecting a first condition of the channel characteristics;

activating a second mode of the LTE access point in which the LTE access point communicates with a WiFi access point and the WiFi access point coordinates the LTE transmissions and the WiFi transmissions on the channel, the second mode activated in response to detecting a second condition of the channel characteristics; and

activating, at the LTE access point, a third mode of the LTE access point in which the LTE access point and the WiFi access point each conduct a portion of the coordination of the LTE transmissions and the WiFi transmissions on the channel, the third mode activated in response to detecting a third condition of the channel characteristics.

13. The method of claim 12, wherein:

detecting the first condition of the channel characteristics comprises detecting WiFi traffic on the channel exceeds LTE traffic on the channel by at least a threshold value;

detecting the second condition of the channel characteristics comprises detecting LTE traffic on the channel exceeds WiFi traffic on the channel by at least a threshold value; and

detecting the third condition of the channel characteristics comprises detecting LTE traffic on the channel is within a threshold value of WiFi traffic on the channel.

17. A method, comprising:

determining, at a Long Term Evolution (LTE) access point of a small cell configured to transmit data over an unlicensed LTE band, a transmission window in which to transmit data to one or more devices over a channel of the unlicensed LTE band beginning at a first time, wherein the LTE access point shares the channel with a WiFi access point of the small cell, wherein the channel is selected by;

determining, by the WiFi access point, channel use data indicating traffic on a plurality of channels of the unlicensed LTE band;

transmitting, by the WiFi access point, the channel use data to the LTE access point;

receiving, at the LTE access point, the channel use data from the WiFi access point;

selecting, using the LTE access point, the channel using the received channel use data from the WiFi access point;

calculating, by the LTE access point, a transmission window size corresponding to one or more timeslots available for transmission in the channel;

at a second time prior to the first time, determining, by the WiFi access point, whether the channel is available for the LTE access point to transmit the data for a duration after the first time based on a channel assessment;

in response to determining the channel is available, informing, by the WiFi access point, the LTE access point to transmit a preamble sequence and reserve the channel;

transmitting, by the LTE access point, the preamble sequence to synchronize the LTE access point with one or more nodes;

reserving, by the LTE access point, the channel for transmission by transmitting a reservation frame, the length of the reservation of the channel based on the transmission window size; and

transmitting, by the LTE access point, the data during the transmission window between the first time and the end of a transmission window.

18. The method of claim 17, wherein the channel assessment comprises:

an energy detection process configured to detect interference in the channel, wherein the channel is declared as busy if the interference exceeds an energy detection threshold; and

a preamble and reservation frame detection process configured to detect a preamble sequence and/or reservation frame in the channel, wherein the channel is declared as busy if a preamble sequence and/or reservation frame is detected.

19. The method of claim 17, wherein the reservation frame comprises a duration field, the duration field indicating a period of time lasting until the end of the transmission window.

20. The method of claim 17, wherein a last preamble in the preamble sequence comprises a length field that indicates a period of time lasting until the end of the transmission window.