Bitstream management
OwnerPer Lindgren, Christer Bohm +1inventors
InventorsPer Lindgren, Christer Bohm, Lars Gauffin
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Abstract
The present invention relates to the transferring of data via a shared medium between nodes in a time multiplexed network, wherein said data is transferred in time slots in one or more bitstreams. To obtain an efficient network, the synchronization of parallel bitstreams is of great importance. A high degree of utility is provided by time slot reuse. The above-mentioned characteristics are obtained by regenerating each bitstream as a whole in a node. This also solves problems with dispersion, attenuation, clock gap and clock extraction. The invention is preferably provided using WDM in a DTM network.
Claims39
Method for transferring data in time slots in at least two parallel bitstreams along one or more shared optical media between nodes in a time multiplexed network, comprising the steps of:
- reading, in a node, at least one incoming of said bitstreams as a whole;
- preventing further optical propagation of said incoming bitstream along the shared medium;
- regenerating and transmitting the bitstream as an outgoing bitstream from the node;
- and
- arranging at least one other of said parallel bitstreams to bypass said node without regeneration or essential modification thereof.
Method as claimed in any one of the preceding claims, wherein said network is circuit-switched.
Method as claimed in any one of the preceding claims, wherein said node is arranged to read time slots of said other bitstream, which thus passes said node without being essentially modified or regenerated.
Method as claimed in any one of the preceding claims, wherein said at least one bitstream and said other bitstream are transferred on two different wavelengths in an optical waveguide.
Method for transferring data via a shared medium between nodes in a time multiplexed network according to any one of the preceding claims, wherein:
- data are transferred in time slots in a first and a second bitstream;
- the first and the second bitstream are transferred using wavelength division multiplexing;
- the first and the second bitstream arrive at a node on a first and a second wavelength via at least one optical carrier;
- the wavelengths are separated into the first wavelength V1, transferring the first bitstream, and the second wavelength V2, transferring the second bitstream;
- the first wavelength V1 is converted into electronic form and prevented from further propagation to other nodes;
- data generated in said node is written into predefined time slots in the first bitstream, resulting in a modified bitstream;
- the modified first bitstream is converted into optical form having the wavelength V1;
- the second wavelength V2, transferring the second bitstream, is brought together with the first wavelength V1, transferring the modified first bitstream, for further propagation to other nodes.
Device for transferring data in time slots in at least two parallel bitstreams along one or more shared optical media between nodes in a time multiplexed network, comprising:
- receiving means for reading at least one incoming of said bitstreams as a whole;
- filtering means for preventing further propagation of the incoming bitstream along the shared medium;
- and
- regenerating means for regenerating and transmitting the bitstream as an outgoing bitstream;
- said device being arranged to pass at least one other of said parallel bitstreams by said node without regeneration or essential modification thereof.
Method for synchronising communication in time slots in a time multiplexed network, wherein data is transferred in two or more parallel bitstreams, comprising the steps of:
- generating a first bitstream in a first node;
- providing the first bitstream with a synchronisation pattern defining a frame rate;
- generating at least one second bitstream in a second nod;
- and
- synchronising, in said second node, the start of a frame in the second bitstream to the start of a frame in the first bitstream.
System for synchronisation of communication in time slots in parallel bitstreams in a time multiplexed network, comprising:
- a first node, called master node, being arranged to generate at least a first bitstream and to provide the first bitstream with a synchronisation pattern to define a frame rate;
- a second node, called slave node, being arranged to generate at least one second bitstream and to synchronise the start of a frame in the second bitstream to the start of a frame in the first bitstream.
Method for using time slots in a time multiplexed network, comprising:
- dividing nodes in said network into clusters;
- using a first bitstream for communication between nodes in a first cluster;
- preventing propagation of the first bitstream from the first cluster to other clusters.
System for using time slots for transferring data via a shared medium in the form of an optical waveguide in a time multiplexed network, characterised by:
- the nodes in said network being divided into clusters;
- a first wavelengths being allocated for communication between nodes in a first cluster;
- and comprising means for preventing communication transferred on said first wavelength between nodes in said first cluster from propagating to other clusters using the same wavelength.
Dependencies are inferred from the claim text.