Method, device and software for digital inverse multiplexing

A device for sending a packet of digital data consisting of data elements, comprising:

• a transmission module, adapted for transmitting the data elements;
• a memory module, adapted for storage of the packet of digital data;
• a reading module, adapted for reading each time two data elements from two parts of the memory module, one data element from the rear part of the front subarea of the packet, and one data element from the front part of the rear subarea of the packet;
• an operator, adapted for converting said two data elements, A and B, into one third data element C to be transmitted, said operator performing an operation F(A,B)=C, which operation F is such that there exist operations G, H for which G(A,C)=B and H(B,C)=A, and
• a construction module, adapted for receiving the data elements of the reading module, supplying the data elements to the operator, and receiving the resulting data element from the operator and supplying the data element to the transmis-sion module.

A device for receiving a packet of digital data consisting of data elements, comprising:

• a receiving module, adapted for receiving at least three flows of data elements;
• a memory module, adapted for storage of the data elements;
• an operator, adapted for converting two data elements A and B in one data element C, said operator performing an operation F(A,B)=C, which operation F is such that there exist operations G, H for which G(A,C)=B and H(B,C)=A;
• a counting module, adapted for tallying the quantity of data elements that have been received from each flow;
• a decision module, adapted for determining whether all data elements that are necessary for reconstructing the complete packet of digital data are present and to determine which part of the packet has to be determined by means of reconstruction, and
• a reconstruction module for retrieving each time two data elements A and B from the memory means, one of the data elements originating from one of the flows and the other data elements originating from one of the other flows, which reconstruction module is connected to the operator for supplying said data elements A and B to the operator, discharging the resul-ting data element C of the operator and writing the resulting data element C to the memory module.

An apparatus comprising a machine-readable medium containing instructions which, when executed by a machine, cause the machine to perform operations comprising:

• splitting a packet of digital data elements into a front sub-packet and a rear sub-packet;
• sending at least three flows:
• a first flow wherein the packet of digital data is sent starting from the front end;
• a second flow wherein the packet of digital data is sent staring from the rear, and;
• a third flow of third data elements C obtained from each time a first data element A from the rear part of the front sub-packet and a second data element B from the front part of the rear sub-packet that are reduced into one third data element by means of an operation F(A,B)=C which operation F is such that there exist operations G, H for which G(A,C)=B and H(B,C)=A;
• sending from a transmitting device the first, second and third flow to a first, second and third receiving device, respectively, and wherein the first, second and third receiving device forward their respective flows to the other two receiving devices;
• retrieving two data elements from the memory means, one data element from the rear part of the front subarea of the packet, and one data element from the front part of the rear subarea of the packet;
• converting said two data elements into one data element by means of the operation F(A,B);
• transmitting a wanted flow of data elements, and
• receiving and processing an instruction from a receiver of a flow of data elements to stop transmitting.

An apparatus comprising a machine-readable medium containing instructions which, when executed by a machine, cause the machine to perform operations comprising:

• receiving a packet of digital data that is sent in at least three flows of data elements;
• writing the data elements of the flows of data elements to the memory means;
• tallying the quantity of data elements that have been received from each flow;
• determining whether all data elements that are necessary for reconstructing the complete packet of digital data are present and to determine which part of the packet has to be determined by means of reconstruction;
• converting two data elements into one data element by means of an operation F(A,B)=C which operation F is such that there exist operations G, H for which G(A,C)=B and H(B,C)=A;
• retrieving each time two data elements from the memory means, for supplying said data elements to the operator routine, for discharging the resulting data element from the operator routine, and writing the resulting data element to the memory means.