	US 12,081,643 B2
	Methods for nanosecond-scale time synchronization over a network
Philip A. Kratz, Redwood City, CA (US); Mainak Chowdhury, Redwood City, CA (US); Alexander Hooshmand, Redwood City, CA (US); and Daniel M. Jacker, Redwood City, CA (US)
Assigned to ZaiNar, Inc., Redwood City, CA (US)
Filed by ZaiNar, Inc., Redwood City, CA (US)
Filed on Feb. 1, 2022, as Appl. No. 17/590,621.
Application 17/590,621 is a continuation of application No. 17/025,635, filed on Sep. 18, 2020, granted, now 11,271,713.
Application 17/025,635 is a continuation of application No. 16/405,922, filed on May 7, 2019, granted, now 10,833,840, issued on Nov. 10, 2020.
Claims priority of provisional application 62/734,978, filed on Sep. 21, 2018.
Claims priority of provisional application 62/668,219, filed on May 7, 2018.
Prior Publication US 2022/0158816 A1, May 19, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 7/00 (2006.01); H04L 7/04 (2006.01); H04L 7/08 (2006.01); H04W 64/00 (2009.01)

CPC H04L 7/08 (2013.01) [H04L 7/0016 (2013.01); H04L 7/041 (2013.01); H04W 64/003 (2013.01)]

20 Claims

1. A transceiver comprising:

a transmit chain;

a receive chain;

self-receive hardware coupling the transmit chain to the receive chain;

a first clock; and

a processor configured to:

generate a first synchronization signal via the transmit chain;

sample a first self-receive signal via self-receive hardware and the receive chain;

calculate a time-of-arrival of the first self-receive signal based on the first clock;

sample a second synchronization signal via the receive chain, the second synchronization signal transmitted by a second transceiver;

calculate a time-of-arrival of the second synchronization signal based on the first clock; and

calculate a time bias between the first clock and a second clock of the second transceiver based on the time-of-arrival of the first self-receive signal and the time-of-arrival of the second synchronization signal.