Ring network communication structure on an optical carrier and reconfigurable node for said structure

Claim 2

Communication structure as claimed in claim 1, characterized in that, in the absence of failures, said at least one first wavelength (λ₁) on said at least one second optical carrier (3B) and said at least one second wavelength (λ₂) on said at least one first optical carrier (3A), are utilised as protection wavelengths to transport low-priority traffic.

Claim 3

Communication structure as claimed in any of the previous claims, characterized in that at least some of said nodes (2A, ..., 2F) comprise signal insertion-extraction devices (13).

Claim 4

Reconfigurable node for a ring network communication structure, said node presenting a first and a second side where a respective connection ends, each connection comprising at least one first (3A) and one second (3B) optical carrier, characterized in that the node comprises: - first (10A) and second (10B) wavelength demultiplexing means operating at said at least one first (λ₁) and one second (λ₂) wavelength and associated respectively to said at least one first optical carrier (3A) on said first side and to said at least one second optical carrier (3B) on said second side, - first (120A) and second (120B) wavelength multiplexing means operating at said at least one first (λ₁) and one second (λ₂) wavelength and associated respectively to said at least one first optical carrier (3A) on said second side and to said at least one second optical carrier (3B) on said first side, and - optical signal switching means (11A, 11B, 12A, 12B) connected between said first (10A) and a second (10B) demultiplexing means and said first (120A) and second (120B) multiplexing means; said switching means (11A, 11B, 12A, 12B) being selectively reconfigurable between a regular operation configuration, at least one first protection configuration, which can be adopted in the presence of a failure on the respective connection on said second side, and at least one second protection configuration, which can be adopted in the presence of a failure on the respective connection on said first side.

Claim 5

Node as claimed in claim 4, characterized in that said switching means (11A, 11B, 12A, 12B) are reconfigurable so that: - in said regular operation configuration, said first (10A) and second (10B) demultiplexing means as well as said first (120A) and second (120B) multiplexing means are active, the incoming optical signals at said at least one first wavelength (λ₁) present on said at least one first carrier (3A) on said first side pass to said at least one first carrier (3A) on said second side, through said first demultiplexing means (10A), said switching means (11A, 12A) and said first multiplexing means (120A), and the incoming optical signals at said at least one second wavelength (λ₂) present on said at least one second carrier (3B) on said second side pass to said at least one second carrier (3B) on said first side, through said second demultiplexing means (10B), said switching means (11B, 12B) and said second multiplexing means (120B), - in said first protection configuration, said second demultiplexing means (10B) and said first multiplexing means (120A) are inactive and incoming signals at said at least one first (λ₁) and one second (λ₂) wavelength, present on said at least one first carrier (3A) on said first side, pass to said at least one second carrier (3B) on said first side through said first demultiplexing means (10A), said switching means (11A, 12B), and said second multiplexing means (120B), - in said second protection configuration, said first demultiplexing means (10A) and said second multiplexing means (120B) are inactive, and incoming signals at said at least one first (λ₁) and one second (λ₂) wavelength, present on said at least one second carrier (3A) on said second side, pass to said at least one first carrier (3A) on said second side through said second demultiplexing means (10A), said switching means (11A, 12B) and said first multiplexing means (120B).

Claim 6

Node as claimed in claim 4 or claim 5, characterized in that said first and second demultiplexing means (10A, 10B), said switching means (11A, 11B, 12A, 12B) and said first and second multiplexing means (120A, 120B) operate in such a way that, in the presence of a failure on a connection not adjacent to the node itself, the incoming signals at said at least one first (λ₁) and one second (λ₂) wavelength, present on said at least one first carrier (3A) on said first side, pass to said at least one first carrier (3A) on said second side through said first multiplexing means (120A), while the incoming signals at said at least one first (λ₁) and one second wavelength (λ₂), present on said at least one second carrier (3B) on said second side, pass to said at least one second carrier (3B) on said first side through said second demultiplexing means (10B), said switching means (11A, 11B, 12A, 12B) and said second multiplexing means (120B).

Claim 7

Node as claimed in any one of claims 4 to 6, characterized in that said switching means comprise: - at least one first switch (11A) operating between said first demultiplexing means (10A) and said first multiplexing means (120A) in said regular operation configuration and in said at least a first protection configuration; said at least one first switch (11A) operating instead between said second demultiplexing means (10B) and said first multiplexing means (120A) in said at least one second protection configuration; and - at least one second switch (11B) operating between said second demultiplexing means (10B) and said second multiplexing means (120B) in said regular operation configuration and in said at least one second protection configuration; said at least one second switch (11B) operating instead between said first demultiplexing means (10A) and said second multiplexing means (120B) in said at least one first protection configuration.

Claim 8

Node as claimed in any one of claims 4 to 7, characterized in that it comprises a signal insertion and extraction device (13) including first receiving means (14A) and first transmitting means (15A) operating at said at least one first wavelength (λ₁), and second receiving means (15B) and second transmitting means (14B) operating at said at least one second wavelength (λ₂), and in that said switching means comprise at least one first switching stage (11A, 11B) arranged to operate between whichever of said first (10A) and said second (10B) demultiplexing means is currently active and said first (14A) and second (15B) receiving means, and a second switching stage (12A, 12B) arranged to operate between said first (15A) and second (14B) transmitting means and at least one of said first (120A) and said second (120B) multiplexing means which is currently active.

Claim 9

Node as claimed in claim 8, characterized in that, in said regular operation configuration, said first switching stage (11A, 11B) conveys respective signals from said first (10A) and second (10B) demultiplexing means towards respective first (14A) and second (15B) receiving means, while in said at least one first and one second protection configuration said first switching stage (11A, 11B) conveys said respective signals from whichever of said first (10A) and second (10B) demultiplexing means is currently active towards respective first (14A) and second (15B) receiving means.

Claim 10

Node as claimed in claim 8 or claim 9, characterized in that in said regular operation configuration, said second switching stage (12A, 12B) conveys respectively signals between said first (15A) and second (14B) transmitting means and said first (120A) and second (120B) multiplexing means, while in said at least one first and one second protection configuration, said second switching stage (12A, 12B) conveys said respective signals between said first (15A) and second (14B) transmitting means and whichever of said first (120A) and second (120B) multiplexing means is currently active.