Data transmitting apparatus, data receiving apparatus and data transmission control apparatus

A data transmitting method for isochronous transmission wherein a transmitting medium needs to be allocated a bandwidth when the isochronous transmission takes place, said method comprising:

• the first bandwidth determining step which calculates a maximum size of a packet for isochronous data from a maximum transmitting data size, land determines a necessary bandwidth for transmitting the packet from the maximum size of the packet for the isochronous data and a data rate of the transmitting medium;
• a second bandwidth determining step which determines an overhead bandwidth from a propagation delay identifier value using a corresponding table between the propagation delay identifier and the overhead bandwidth;
• an adding step which adds the bandwidth from the first bandwidth determining step and the bandwidth from the second bandwidth determining step and;
• an allocation step which allocates a corresponding bandwidth to the added value calculated at the adding step.