Patent ID: 9634762
Date: 2017-04-25
CPC Classifications: H04B,H04Q

Claim:
1. 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 measured 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; determining, executed by a processor, when the first quality information is above a predetermined threshold, the first route is reachable; retrieving measured second quality information representing a quality of the optical signal 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; retrieving measured third quality information representing a quality of the optical signal 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; comparing, executed by the processor, the second quality information with the third quality information; when the third quality information is greater than or equal to the second quality information, determining, executed by the processor, the second route is reachable; and when the third quality information is less than the second quality information, determining, executed by the processor, the second route is not reachable.