Time synchronization of a wireless network

Patent metadata

Field	Value
Publication number	US-11070348-B1
Application number	US-201916716224-A
Country	US
Kind code	B1
Filing date	Dec 16, 2019
Priority date	Dec 16, 2019
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

Apparatuses, methods, and systems for synchronizing nodes of a wireless network are disclosed. One method includes identifying synchronization paths between synchronization reference nodes of the wireless network and each non-reference node of the wireless network, wherein each synchronization path includes one or more wireless hops between the synchronization reference nodes and the non-reference node, determining a number of timing slots needed for supporting each of the identified synchronization paths, and selecting at least one of the synchronization paths between each non-reference node and at least one of the synchronization reference nodes based on a number of wireless hops of each of the identified synchronization paths and the determined number of timing slots needed to support each of the identified synchronization paths.

First claim

What is claimed:

1. A method of synchronizing nodes of a wireless network, comprising:
identifying synchronization paths between one or more synchronization reference nodes of the wireless network and each non-reference node of the wireless network, wherein each synchronization reference node receives a synchronization signal or is designated as a source of the synchronization signal, and each non-reference node does not directly receive the synchronization signal and is not designated as a source of the synchronization signal, wherein each synchronization path includes one or more wireless hops between the one or more synchronization reference nodes and the non-reference node;
determining a number of timing slots needed for supporting each of the identified synchronization paths; and
selecting at least one of the synchronization paths between each non-reference node and at least one of the synchronization reference nodes based on a number of wireless hops of each of the identified synchronization paths and the determined number of timing slots needed to support each of the identified synchronization paths;
wherein at least one of the synchronization reference nodes or at least one intervening non-reference node includes an antenna array that forms a beamforming pattern having multiple beams.

2. The method of claim 1 , further comprising the one or more synchronization reference nodes communicating the synchronization signal to each of the non-reference node through the selected at least one of the synchronization paths.

3. The method of claim 1 , wherein selecting at least one of the synchronization paths between each non-reference node and one or more synchronization reference nodes is further based on selecting a redundant number of synchronization paths between each non-reference node and the one or more synchronization reference nodes.

4. The method of claim 1 , wherein at least one of the selected at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is different than a data path to the non-reference nodes.

5. The method of claim 1 , further comprising the at least one of the synchronization reference nodes or at least one intervening non-reference node that includes that antenna array that forms the beamforming pattern having multiple beams broadcasting a synchronization signal to non-reference nodes through the multiple beams.

6. The method of claim 1 , wherein selecting at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is further based on maintaining synchronization errors between the synchronization reference nodes and the non-reference node within a selected threshold.

7. The method of claim 1 , wherein selecting at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is further based on maintaining synchronization errors between the synchronization reference nodes and the non-reference node of a local region within a selected threshold.

8. The method of claim 7 , wherein the local region is based on levels of interference based on antenna patterns of the synchronization reference nodes and the non-reference nodes.

9. The method of claim 1 , further comprising at least one of the synchronization reference nodes and the non-reference nodes characterizing beamforming patterns between the synchronization reference nodes and the non-reference nodes, and wherein a central network controller performs the selecting at least one of the synchronization paths between each non-reference nodes and at least one of the synchronization reference nodes additionally based on the characterized beamforming patterns.

10. A wireless network, comprising:
a plurality of synchronization reference nodes;
a plurality of non-reference nodes;
a controller, wherein the controller operates to:
identify synchronization paths between one or more synchronization reference nodes of the wireless network and each non-reference node of the wireless network, wherein each synchronization reference node receives a synchronization signal or is designated as a source of the synchronization signal, and each non-reference node does not directly receive the synchronization signal and is not designated as a source of the synchronization signal, wherein each synchronization path includes one or more wireless hops between the synchronization reference nodes and the non-reference node;
determine a number of timing slots needed for supporting each of the identified synchronization paths; and
select at least one of the synchronization paths between each non-reference node and at least one of the synchronization reference nodes based on a number of wireless hops of each of the identified synchronization paths and the determined number of timing slots needed to support each of the identified synchronization paths;
wherein at least one of the synchronization reference nodes or at least one intervening non-reference node includes an antenna array that forms a beamforming pattern having multiple beams.

11. The wireless network of claim 10 , wherein one or more synchronization reference nodes communicate a synchronization signal to each of the non-reference node through the selected at least one of the synchronization paths.

12. The wireless network of claim 10 , wherein selecting at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is further based on selecting a redundant number of synchronization paths between each non-reference node and one or more of the synchronization reference nodes.

13. The wireless network of claim 10 , wherein at least one of the selected at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is different than a data path to the non-reference nodes.

14. The wireless network of claim 10 , wherein the at least one of the synchronization reference nodes or the intervening non-reference nodes that includes that antenna array that forms the beamforming pattern having multiple lobes broadcasting a synchronization signal to non-reference nodes through the multiple beams.

15. The wireless network of claim 10 , wherein selecting at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is further based on maintaining synchronization errors between the synchronization reference nodes and the non-reference node within a selected threshold.

16. The wireless network of claim 10 , wherein selecting at least one of the synchronization paths between each non-reference node and one of the synchronization reference nodes is further based on maintaining synchronization errors between the synchronization reference nodes and the non-reference node of a local region within a selected threshold.

17. The wireless network of claim 16 , wherein the local region is based on levels of interference based on antenna patterns of the synchronization reference nodes and the non-reference nodes.

18. The wireless network of claim 16 , wherein the local region is based on levels of interference based on interference measurements between the synchronization reference nodes and the non-reference nodes.

Assignees

• Facebook Inc

Inventors

• Huang Po-Han
• Gomadam Krishna
• Dunn Brian
• Singla Anubhav
• Sun Fan

Classifications

• H04L12/189

  in combination with wireless systems (selective distribution or broadcast in wireless communication networks H04W4/06) · CPC title

• H04J3/0679

  by determining clock distribution path in a network · CPC title

• H04W56/0015 Primary

  one node acting as a reference for the others · CPC title

• H04B7/0617

  for beam forming · CPC title

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title