Virtual concatenation of PDH signals
AssigneesPMC-Sierra, Inc., Agere Systems Inc.
InventorsSteven Gorshe, Nevin Jones
Life of this patent
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Abstract
Asynchronous/plesiochronous digital hierarchy (PDH) signals, such as DS1 and E1, are transported using virtual concatenation. The packetized data signals are frame encapsulated and subsequently inverse multiplexed into a plurality of PDH frames. An overhead packet is inserted in the transmitted frames to enable the receiver to determine the status of the frames and extract the differential delay experienced by various frames as they are routed through virtually concatenated channels. The extracted delays enables the receiver to realign the various frames of the PDH signal to reconstitute the originally transmitted signals that travel through different paths of the transport network linking the source and sink of the virtually concatenated channel.
Claims27
A method for transmitting data over a plurality of PDH signals configured to be virtually concatenated, the method comprising:
- encapsulating the data packets;
- inverse multiplexing said encapsulated data packets into N PDH signals each comprising P frames;
- inserting a different one of M groups of overhead bits in each of at least one frame or a subframe of each of the M groups of the P frames;
- and
- transmitting each of the MxP frames.
An apparatus configured to transmit data packets over a plurality of asynchronous plesiochronous digital hierarchy (PDH) signals via a virtual concatenation channel, the apparatus comprising:
- an encapsulation module configured to encapsulate the data packets;
- an inverse multiplexer configured to inverse multiplex said encapsulated data packets into N PDH signals each comprising P frames;
- an overhead processor configured to insert a different one of M groups of overhead bits in each of at least one frame or a subframe of each of the M groups of the P frames;
- and
- a transmitter configured to transmit each of the MxP frames.
A method for providing link capacity adjustment scheme (LCAS) to virtually concatenated asynchronous plesiochronous digital hierarchy signals (PDH), the method comprising:
- using control packets defined for SONET/SDH high-order LCAS;
- using one or more multiframe counters defined for SONET/SDH H4 byte for differential delay timing, delineation of the control packets and member status information;
- and
- using PDH signal multiframe as part of differential delay timing to increase the overhead bandwidth available for the control packet with control packet's CRC used to delineate the control packets.
Dependencies are inferred from the claim text.