Modulation and signaling converter

A method of communicating between a first communication device and a second communication device over a communication link comprising a first transmission channel of a first type and a second transmission channel of a second type, the method comprising the steps of:

• (a) transmitting from the first communication device on the first transmission channel a first data block comprising a header portion containing first signaling information corresponding to the first type of transmission channel, for determining transmission characteristics of the first transmission channel;
• and a message portion containing message information bound for the second communication device;
• (b) receiving the first data block at an interface between the first and second transmission channels;
• and
• (c) transmitting from the interface on the second transmission channel a second data block comprising:
• a header portion containing second signaling information corresponding to the second type of transmission channel, for determining transmission characteristics of the second transmission channel;
• and a message portion containing said message information bound for the second communication device, wherein the interface begins transmission of the second data block before reception of the first data block is completed.

A data transmission structure for transmitting inter-device messages between first and second communication devices over a data communication link comprising plural different types of transmission channels, the structure comprising:

• a preamble containing signaling information for determining transmission channel characteristics, wherein the content of the signaling information varies during transmission between the first and second communication devices in accordance with the type of transmission channel carrying the data transmission structure;
• and
• a message block containing message information to be transmitted between the first and second communication devices, the message information contained in the message block remaining the same throughout transmission between the first and second communication devices;
• wherein the content of the signaling information to be transmitted within the preamble on each transmission channel of the communication link is independent of the message information contained in the message block, such that the data transmission structure permits an interface between two types of transmission channels in the communication link to initiate transmission of the preamble of the data transmission structure on one transmission channel before reception of the message block of the data transmission structure on another transmission channel is completed.