US 5,442,623 A · Passive protected self healing ring network

Abstract

A self healing, passive protected ring network and a method of operation are disclosed. The ring network includes a plurality of active nodes interconnected by optical fibers into a working ring. The ring network also includes a passive optical fiber protection ring which interfaces with the working ring through a small number of optical switches located at each node. In the event of a failure in the optical fibers or nodes of the working ring, the optical switches are set to interconnect the protection ring to the nodes on either side of the failure and to bypass all other nodes. It is a particular advantage of the present invention that the protection ring may be installed without modifying or adding to the active electronic equipment at each node and remains unchanged when the working ring's equipment is upgraded to a higher line transmission rate.

Claims10

Dependent claims

A self healing SONET network comprising

a plurality of active electronic nodes interconnected by optical fibers into a working ring, each of said nodes including an add-drop multiplexer, and
a passive protection optical fiber ring comprising a first protection optical switch associated with each of said active nodes and having a bypass state for permitting the protection ring to bypass the corresponding node and an interconnection state in which optical signals are transmitted between said protection ring and said working ring,
each said active electronic node further comprising
a first working optical switch having a normal state in which optical signals are received from said working ring into said node and a protection state in which optical signals are received from said protection ring into said node, via said first protection optical switch of said protection ring associated with said node and
a second working optical switch having a normal state in which optical signals are transmitted from said node to said working ring and a protection state in which optical signals are transmitted from said node to said protection ring, via said first protection optical switch of said protection ring associated with said node.

2 more elements

A self-healing SONET ring network comprising

a plurality of active nodes interconnected by optical fibers to form an active working ring, each of said nodes including an add-drop multiplexor,
a passive only protection optical fiber ring having a by-pass state distinct from each of said nodes, said add-drop multiplexors not being included in said protection optical fiber ring, and
means located at each of said nodes for interconnecting said active working and said passive only protection rings, said interconnecting means including optical switching means in said active working ring, optical switching means in said passive only protection ring, and optical fibers interconnecting said active working ring optical switching means and said passive only protection ring optical switching means, whereby said interconnecting means has a by-pass state in which said passive only protection ring by passes said node in normal operation of the ring network and an interconnection state in which optical signals are interconnected between said active working and said passive only protection rings through said active working ring optical switching means and said passive only protection ring switching means in the event of a failure in the ring network.

Dependencies are inferred from the claim text.

Passive protected self healing ring network

Life of this patent

Passive protected self healing ring network

Life of this patent

Abstract

Claims10