Patent ID: 7860391
Filing Date: 2010-12-28
Classification: H04J

Abstract:
1. A wavelength division multiplexed (WDM) communication system comprising: a first WDM communication link connecting a first gateway node and a second gateway node, said first WDM communication link extending in part through a substantially inaccessible region; a second WDM communication link connecting a third gateway node and a fourth gateway node, said second WDM communication link extending in part through said substantially inaccessible region; a fifth gateway node on a first side of said substantially inaccessible region in optical communication with the first gateway node and the third gateway node; a sixth gateway node on a second side of said substantially inaccessible region in optical communication with the second gateway node and the fourth gateway node; a first client node on the first side of said substantially inaccessible region in optical communication with said fifth gateway node; a second client node on a second side of said substantially inaccessible region in optical communication with said sixth gateway node; and a first cross-gateway link between said first gateway node and said third gateway node configured to provide redundant communications on said first side of said substantially inaccessible region; a second cross-gateway link between said second gateway node and said fourth gateway configured to provide redundant communications on said second side of said substantially inaccessible region; and wherein said first gateway node is in optical communication with said third gateway node via said first cross-gateway link and said second gateway node is in optical communication with said fourth gateway node via said second cross-gateway link; wherein said first client node is configured to transmit a client signal destined for said second client node along a primary path from said fifth gateway node to the first gateway node and across said substantially inaccessible region along said first WDM communication link to said second gateway node and to said sixth gateway node which is configured to route said client signal to said second client node; wherein upon a failure of said first WDM communication link, said fifth gateway node is configured to direct said client signal from the first client node through said third gateway node and across said substantially inaccessible region along said second WDM communication link to said fourth gateway node and to said sixth gateway node which is configured to route said client signal to said second client node; and wherein upon said failure, said fifth gateway node is configured to provide redundant communication for said client signal to said third gateway node by routing the client signal to said first gateway node which is in turn configured to route the client signal to said third gateway node via said first cross-gateway link.