US 6,147,968 AGranted

Method and apparatus for data transmission in synchronous optical networks

AssigneeNortel Networks Limited

InventorsEvert De Moer, Peter Phelps, Bruce Dunn, Gary L. Swinkels, Louis-Rene Pare

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present invention relates to a switching node for use in a synchronous optical network ring, where the ring is transporting data divided into first size blocks, for example OC-192 optical signals, characterized by data blocks of size 192. The switching node includes several primary receive and send connections, for receiving and transmitting inter-ring optical signals divided into second size blocks, for example OC-48 optical signals, characterized by data blocks of size 48. The switching node further includes a secondary receive and send connection for receiving and transmitting intra-ring optical signals divided into first size blocks. A critical component of the switching node is the main controller, responsible for routing incoming intra-ring first size blocks towards a primary send connection. The main controller divides a first size block into smaller second size blocks, observes the second size blocks for the presence of concatenated data and, in the case where there is presence of concatenated data, routes the second size block as a single unit towards the adjacent network ring. In the case where there is absence of concatenated data, the routing controller routes the group of data forming the second size block as independent data elements towards the adjacent network ring.

Claims21

Dependent claims

A switching node for use in a synchronous optical network ring transporting data divided into first size blocks, said switching node including:

a plurality of primary receive connections for receiving inter-ring optical signals divided into second size blocks, where a second size block is smaller than a first size block, a second size block including a header section and a payload section, the header section including a mark related to at least a portion of the payload section, the mark being indicative as to whether the portion of the payload section is concatenated data or non concatenated data, when the portion of the payload section is non concatenated data it includes a plurality of independent data elements;
a plurality of primary send connections for transmitting inter-ring optical signals divided into second size blocks;
a secondary receive connection for receiving intra-ring optical signals divided into first size blocks;
a secondary send connection for transmitting intra-ring optical signals divided into first size blocks;
a main controller for routing of first size blocks towards the primary send connections, said main controller being operative to:
a) divide an incoming first size block into at least two second size blocks;
b) observe the mark in the header section of a second size block to determine whether the payload section of the second size block includes concatenated data and acquiring either one of two data transmission modes in dependence of the mark;
i) If the mark is indicative of presence of concatenated data in the payload section of the second size block, said main controller acquires a first data transmission mode where the concatenated data is routed as a single unit towards a particular primary send connection;
and
ii) If the mark is indicative of absence of concatenated data in the payload section of the second size block, said main controller acquires a second data transmission mode permitting routing of independent data elements contained in the payload section of the second size block towards different primary send connections.

7 more elements

A method for managing the transmission of optical signal concatenated payloads in a switching node of a synchronous optical network ring transporting data divided into first size blocks, said switching node including:

a plurality of primary receive connections for receiving inter-ring optical signals divided into second size blocks, where a second size block is smaller than a first size block, a second size block including a header section and a payload section, the header section including a mark related to at least a portion of the payload section, the mark being indicative as to whether the portion of the payload section is concatenated data or non concatenated data, when the portion of the payload section is non concatenated data it includes a plurality of independent data elements;
a plurality of primary send connections for transmitting inter-ring optical signals divided into second size blocks;
a secondary receive connection for receiving intra-ring optical signals divided into first size blocks;
a secondary send connection for transmitting intra-ring optical signals divided into first size blocks;
said method comprising the steps of:
a) receiving an incoming first size block;
b) dividing said first size block into at least two second size blocks, where a second size block includes a header section and a payload section;
c) processing a second size block to determine whether the payload section of said second size block includes concatenated data;
d) routing the second size block towards an adjacent optical network ring in dependence of the presence of concatenated data, if there is presence of concatenated data said concatenated data is routed as a single unit towards a particular primary inter-ring connection, if there is absence of concatenated data the data contained in said payload section of the second size block may be routed as independent data elements towards different primary inter-ring connections.

6 more elements

Dependencies are inferred from the claim text.