Optical switch and protocols for use therewith
First Claim
1. A method of establishing a connection along a path in a communications network, the communications network comprising a plurality of switching nodes interconnected by optical links, the path being defined between a first one of the switching nodes and a second one of the switching nodes via at least one intermediate switching node, the at least one intermediate switching node being disposed between a respective first link and a respective second link of the path, the method comprising, at the at least one intermediate switching node:
- maintaining an association between the respective first link and a respective first wavelength, the first wavelength being available on the respective first link;
receiving a message from a one of;
the second one of the switching nodes and another intermediate switching node, the message indicative of an association between the respective second link and a respective second wavelength, the respective second wavelength being available on the respective second link;
mapping the combination of the respective first link and the respective first wavelength to the combination of the respective second link and the respective second wavelength; and
storing the result of mapping in a memory element.
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Accused Products
Abstract
A method of establishing a data connection between terminal switching nodes in a network and switching nodes for implementing the method. The method involves switching nodes participating in a network layer wavelength routing (WR) protocol to determine the next hop switching node for every possible combination of terminal nodes based on the network topology. The method also involves the switching nodes participating in a network layer wavelength distribution (WD) once the data connection is to be established. The WR protocol determines the path used through the network, while the WD protocol assigns wavelengths on each link between switching nodes. The wavelengths may be different on different optical links. The switching nodes include wavelength converters with an optical switch or optoelectronic converters with a digital electronic switch. A digital electronic switch can also provide signal reformatting. Advantages of using potentially different wavelengths along various segments of a single end-to-end connection yields increased wavelength efficiency.
3 Citations
14 Claims
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1. A method of establishing a connection along a path in a communications network, the communications network comprising a plurality of switching nodes interconnected by optical links, the path being defined between a first one of the switching nodes and a second one of the switching nodes via at least one intermediate switching node, the at least one intermediate switching node being disposed between a respective first link and a respective second link of the path, the method comprising, at the at least one intermediate switching node:
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maintaining an association between the respective first link and a respective first wavelength, the first wavelength being available on the respective first link; receiving a message from a one of;
the second one of the switching nodes and another intermediate switching node, the message indicative of an association between the respective second link and a respective second wavelength, the respective second wavelength being available on the respective second link;mapping the combination of the respective first link and the respective first wavelength to the combination of the respective second link and the respective second wavelength; and storing the result of mapping in a memory element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of establishing a connection along a path in a communications network, the communications network comprising a plurality of switching nodes interconnected by optical links, the path being defined between a first one of the switching nodes and a second one of the switching nodes via at least one intermediate switching node, the at least one intermediate switching node being disposed between a first link and a second link of the path, the method comprising, at the at least one intermediate switching node:
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receiving a connection request message from the first one of the switching nodes over a first link; determining whether there is a free wavelength available between the first one of the switching nodes and the at least one intermediate switching node over the first link; if there is a free wavelength available, the free wavelength is determined to be the first wavelength, and generating an association between the first wavelength and the first link; sending a connection request message to the second one of the switching nodes; receiving a message from a one of;
the second one of the switching nodes and another intermediate switching node, the message indicative of an association between the second link and a second wavelength, the second wavelength being available on the second link between the at least one intermediate switching node and a one of;
the second one of the switching nodes and the other intermediate switching node;mapping the association of the first link and the first wavelength to the association of the second link and the second wavelength; and storing the mapping in a memory element. - View Dependent Claims (12, 13, 14)
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Specification