US 11,722,288 B2
Time synchronization path selection device and time synchronization path selection method
Kaoru Arai, Tokyo (JP); Hiroki Sakuma, Tokyo (JP); Masahiro Nakagawa, Tokyo (JP); and Shunichi Tsuboi, Tokyo (JP)
Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (JP)
Appl. No. 17/413,863
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Dec. 6, 2019, PCT No. PCT/JP2019/047787
§ 371(c)(1), (2) Date Jun. 14, 2021,
PCT Pub. No. WO2020/129701, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 2018-235731 (JP), filed on Dec. 17, 2018.
Prior Publication US 2022/0060310 A1, Feb. 24, 2022
Int. Cl. H04L 7/00 (2006.01); H04J 3/06 (2006.01); H04W 40/02 (2009.01); H04W 56/00 (2009.01)
CPC H04L 7/0016 (2013.01) [H04J 3/0679 (2013.01); H04W 40/02 (2013.01); H04W 56/001 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A time synchronization route selection apparatus having a function of a time synchronization apparatus used in a time transmission system in which time synchronization packets are transmitted and received by time synchronization apparatuses, and times of the time synchronization apparatuses are synchronized based on time information of transmission and reception, wherein in the time transmission system, the time synchronization apparatuses having different types of apparatus performances are included, and a plurality of routes of the time synchronization packets from a time reference apparatus to the time synchronization route selection apparatus via the time synchronization apparatuses are present, each time synchronization apparatus located upstream on each route performs notification of performance information indicating an apparatus performance of the time synchronization apparatus to a time synchronization apparatus located downstream with respect thereto, and the time synchronization route selection apparatus includes:
a determination index calculation unit, including one or more processors, configured to calculate a determination index for each route by referencing the performance information notified from the time synchronization apparatuses located upstream on the route, wherein the determination index calculation unit is configured to:
use precision classes registered in advance in the time synchronization apparatuses as the performance information notified from the time synchronization apparatuses, and
calculate the determination index for each route based on a spec value defined for each precision class, and a number of time synchronization apparatuses corresponding to the spec value; and
a route selection unit, including one or more processors, configured to, based on the calculated determination index for each route, select a route for transmitting and receiving the time synchronization packets from a plurality of routes of the time synchronization packets to the time synchronization route selection apparatus.