OPTICAL TRANSMISSION SYSTEM, NODE APPARATUS, AND REACHABILITY DETERMINATION METHOD

• US 20140133849A1
• Filed: 10/01/2013
• Published: 05/15/2014
• Est. Priority Date: 11/14/2012
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: GOTO, Ryosuke, ISHII, Shigeru
• Granted Patent: US 9,319,132 B2
• Time in Patent Office: Days
• US Class Current: 398/26
• CPC Class Codes: H04B 10/0775 Performance monitoring and measurement of transmission parameters
• CPC Class Codes: H04B 10/0791 Fault location on the transmission path
• CPC Class Codes: H04B 10/0793 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04B 10/0795 Performance monitoring; Measurement of transmission parameters
• CPC Class Codes: H04B 10/07953 Monitoring or measuring OSNR, BER or Q
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0043 Fault tolerance

Abstract

A node apparatus is installed at a node located on a route from a start node to an end node, and includes: a parameter calculating unit configured to, upon receiving routing information specifying the route and a first parameter representing an amount of signal degradation, update the first parameter by using a second parameter representing an amount of signal degradation along a transmission route to an adjacent node, and generate a third parameter representing an amount of signal degradation along a transmission route between the start node and the node, specified by the routing information; and a determination unit configured to determine reachability of the route specified by the routing information in accordance with the third parameter and a fourth parameter representing an amount of signal degradation along a transmission route from the node to the end node specified by the routing information.

Claims

1. A node apparatus installed at a first node located on a route from a start node to an end node, the node apparatus comprising:

a parameter calculating unit configured to, upon receiving routing information specifying the route and a first parameter representing an amount of signal degradation, update the first parameter by using a second parameter representing an amount of signal degradation along a transmission route to an adjacent node, and generate a third parameter representing an amount of signal degradation along a transmission route between the start node and the first node, specified by the routing information; and

a determination unit configured to determine reachability of the route specified by the routing information in accordance with the third parameter generated by the parameter calculating unit and a fourth parameter representing an amount of signal degradation along a transmission route from the first node to the end node specified by the routing information.

2. The node apparatus according to claim 1, further comprising:

a storage unit configured to store an amount of degradation parameter representing an amount of signal degradation along a transmission line between the first node and an end node of a first route on which signals pass through the first node,

wherein a second route is specified by the routing information, and

wherein if signals pass through the first node on the second route, and if the end node of the first route and an end node of the second route match each other, the determination unit determines reachability of the second route by using the amount of degradation parameter stored in the storage unit as the fourth parameter.

3. The node apparatus according to claim 2,

wherein first span count information representing a number of spans along a transmission route between the first node and the end node of the first route is stored in the storage unit,

wherein the parameter calculating unit detects a number of spans along a transmission route between the start node of the second route and the first node by receiving, from an adjacent node on the second route, second span count information representing a number of spans that is incremented at each pass at each node, and detects a total number of spans of the second route in accordance with the first span count information and the second span count information, and

wherein the determination unit determines reachability of the second route in accordance with an amount of signal degradation determined by the third parameter, the fourth parameter, and the total number of spans of the second route.

4. The node apparatus according to claim 1, further comprising:

a transmitter configured to transmit the routing information and the third parameter to an adjacent node specified by the routing information.

5. An optical transmission system comprising:

a plurality of node apparatuses installed at first nodes located on a route from a start node to an end node, wherein each of the node apparatuses includes;

a receiver configured to receive, from an adjacent node, routing information specifying the route and a first parameter representing an amount of signal degradation;

a parameter calculating unit configured to update the first parameter by using a second parameter representing an amount of signal degradation along a transmission route to the adjacent node, and generate a third parameter representing an amount of signal degradation along a transmission route between the start node and the first node, specified by the routing information;

a determination unit configured to determine reachability of the route specified by the routing information in accordance with the third parameter generated by the parameter calculating unit and a fourth parameter representing an amount of signal degradation along a transmission route from the first node to the end node specified by the routing information; and

a transmitter configured to transmit the routing information and the third parameter to an adjacent node specified by the routing information.

6. A reachability determination method comprising:

detecting an overlap portion of a first route and a second route where a start node and an end node of the first route respectively match a start node and an end node of the second route;

retrieving first quality information representing a quality of an optical signal that is obtained when the optical signal is transmitted from the start node to the end of the first route, second quality information representing a quality that is obtained when the optical signal is transmitted along a partial route of the first route other than the overlap portion of the first route, and third quality information representing a quality that is obtained when the optical signal is transmitted along a partial route of the second route other than the overlap portion of the second route; and

determining reachability of the second route in accordance with the first quality information, the second quality information, and the third quality information.