Ring/mesh optical network

An optical network, comprising:

• a plurality of optical cross-connect switches, including first, second, and third optical cross-connect switches;
• a plurality of spare optical channels, and
• a plurality of working optical channels, wherein
• said plurality of optical cross-connect switches are optically coupled in a ring configuration using said plurality of working optical channels and said plurality of spare optical channels such that N spare optical channels and N working optical channels are provided between each pair of adjacent optical cross-connect switches in said ring configuration, N being an integer greater than two, thereby forming an optical ring network, and in the event any of said N working optical channels provided between a first pair of adjacent optical cross-connect switches are not available for carrying data traffic said plurality of optical cross-connect switches are switched to loop-back said data traffic from said working channels onto said plurality of spare optical channels except said N spare optical channels provided between said first pair of adjacent optical cross-connect switches wherein said plurality of optical cross-connect switches are switched to form N spare optical channel rings using said N spare optical channels provided between said each pair of adjacent optical cross-connect switches in said ring configuration.

An optical network, comprising:

• a plurality of optical cross-connect switches, including first, second, and third optical cross-connect switches, wherein at least two of said plurality of optical cross-connect switches are optically coupled to one or more optical cross-connect switches that format of a mesh network;
• a plurality of spare optical channels, wherein one of said plurality of spare optical channels is shared with said mesh network such that in the event of a failure in said mesh network said one of said plurality of spare optical channels carries data traffic originating in said mesh network;
• a plurality of working optical channels, wherein said plurality of optical cross-connect switches are optically coupled in a ring configuration using said plurality of working optical channels and said plurality of spare optical channels such that N spare optical channels and N working optical channels are provided between each pair of adjacent optical cross-connect switches in said ring configuration, N being an integer greater than zero, thereby forming an optical ring network, wherein said optical ring network includes means for establishing a priority of use of said spare optical channel shared with said mesh network such that said spare optical channel shared with said mesh network is utilized by said mesh network only when there are no failures in said optical ring network;
• and
• in the event any of said N working optical channels provided between a first pair of adjacent optical cross-connect switches are not available for carrying data traffic, said plurality of optical cross-connect switches are switched to loop-back said data traffic from said working channels onto said plurality of spare optical channels except said N spare optical channels provided between said first pair of adjacent optical cross-connect switches.

A method for creating an optical network that exhibits the simplicity and fast switching of an ADM ring network and offers the spare efficiency and ease of growth characteristics of a mesh network, comprising the steps of:

• optical coupling a plurality of optical cross-connect switches in a ring configuration using a plurality of working optical channels and a plurality of spare optical channels such that a spare optical channel and a working optical channel is provided between each pair of adjacent optical cross-connect switches in said ring configurations;
• transmitting data traffic between a first pair of adjacent optical cross-connect switches using said working optical channel provided between said first pair of adjacent optical cross-connect switches;
• optically coupling at least two of said plurality of optical cross-connect switches to one or more optical cross-connect switches that form part of an optical mesh network;
• in the event said working optical channels provided between said first pair of adjacent optical cross-connect switches is not available for transmitting data traffic, transmitting said data traffic between said first pair of adjacent optical cross-connect switches using said plurality of spare optical channels except said spare optical channel provided between said first pair of adjacent optical cross-connect switches;
• and
• switching said plurality of optical cross-connect switches to form a spare optical channel ring using said plurality of spare optical channels.

A method for enabling an optical cross-connect switch to participate in both a ring configuration and a mesh configuration, comprising the steps of:

• provisioning a first set of ports in the optical cross-connect switch to support ring traffic;
• provisioning a second set of ports in the optical cross-connect switch to support mesh traffic
• connecting a set ports in to a first working optical channel;
• connecting second port from said first set to a first spare optical channel;
• connecting a third port from said first set to a second working optical channel;
• connecting a fourth port from said first set to a second spare optical channel;
• connecting a fifth port from said first set to a first network node;
• connecting a sixth port from said first set to a second network node;
• switching said fifth port to said first port, wherein an optical signal transmitted from said first network node is transmitted onto said first working optical channel;
• switching said sixth port to said third port, wherein an optical signal transmitted from said second network node is transmitted onto said second working optical channel;
• and
• switching said second port to said fourth port, thereby connecting said first spare optical channel to said second spare optical channel.