Communication system

• US 6,731,656 B1
• Filed: 10/15/1999
• Issued: 05/04/2004
• Est. Priority Date: 10/16/1998
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Marconi Communications Limited (Marconi Holdings Company Limited)
• Inventors: Arden, Laurence, Slater, Iain J
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): JAIN, RAJ K
• Application Number:
  US09/419,414
• Time in Patent Office: 1,663 Days
• Field of Search: 370/536, 370/537, 370/477, 370/539, 370/541, 370/464-467
• US Class Current: 370/536
• CPC Class Codes: H04J 2203/008 Support of video
• CPC Class Codes: H04J 2203/0085 Support of Ethernet
• CPC Class Codes: H04J 2203/0094 Virtual Concatenation
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04J 3/1617 carrying packets or ATM cells

Abstract

A communications system utilizes, inverse multiplexing to transfer wide band signals over a plurality of narrow band links. To enable efficient use of the available links, incoming data whether or not cell or packet based, is inverse multiplexed in a byte format regardless of packet boundaries into virtual containers. Overhead signals are generated to enable the original data to be reassembled at the receiving end.

Claims

1. A communication system having a synchronous digital hierarchy path between two nodes, the path having virtual containers of a predetermined bandwidth, they system comprising:

means at one of the nodes, for receiving input data including packet based data having a bandwidth greater than said predetermined bandwidth, and means for inverse multiplexing said data in a byte format regardless of packet boundaries onto a plurality of the virtual containers for transmission to the other of the nodes;

means at the other node, for receiving and reassembling said data;

means for compensating for delays caused by different path lengths of individual virtual containers, said plurality of virtual containers being in a phase relationship; and

means at the one node, for inserting into each virtual container overhead bytes which are indicative of the phase relationship.

2. The system as claimed in claim 1, wherein successive bytes are inserted in turn into each of the virtual containers for transmission to the other node.

3. The system as claimed in claim 1, wherein the plurality of virtual containers which carry data derived from a given input broadband data signal includes the overhead bytes to so identify such containers to facilitate reassembly of said data signal.

4. The system as claimed in claim 3, and means for utilizing a three level sequence numbering system to track a sequence of the overhead bytes, one level utilizing a TU or AU pointer to identify a reference byte, a second level using an LSI number to identify a repeating sequence of virtual containers, and a third level using a frame number indicator (FNUM) for identification of differing path delays.

5. The system as claimed in claim 4, and means at the other node, for reordering data utilizing LSI and FNUM, whereby the bytes having a lower FNUM value exit first, and the bytes with the same FNUM value but a lower LSI number exit before those with a higher LSI number.

6. The system as claimed in claim 1, and the one node being adapted to receive a plurality of input data streams, each having a different bandwidth and signal format.

7. The system as claimed in claim 6, and means for increasing or reducing a number of the virtual containers associated with transport of a particular input data stream in dependence upon changes in a type and/or bandwidth of input data which is received.

8. The system as claimed in claim 1, wherein the virtual containers have differing bandwidths.