Advanced priority statistical multiplexer

A method for transmitting high priority data and low priority data over a communications link in a hybrid data frame of length Fn bytes, the communications link having a baud rate, the communications link transferring bytes equal to Y bits, and the communications link having a byte transfer period equal to Y divided by the baud rate, the method comprising the steps of:

• a. determining a high priority packet time;
• b. determining a maximum number of bytes transferred across the communications link in one high priority packet time by dividing the high priority packet time by the byte transfer period;
• c. determining a worst case number of high priority data bytes transferred across the communications link in one high priority packet time;
• d. subtracting the worst case number of high priority data bytes from the maximum number of bytes to obtain an interrupt boundary byte count;
• and
• e. transmitting high priority data bytes and low priority data bytes, comprising the substeps of:
• 1) setting a frame length count equal to the frame length;
• 2) transmitting header information;
• 3) if there are high priority data bytes to be transferred across the link, transmitting high priority data bytes, concluding with a final high priority data byte, and decrementing the frame length count for each high priority data byte transmitted;
• 4) if there are low priority data bytes to be transferred across the link, transmitting K low priority data bytes, K not exceeding the interrupt boundary byte count, and decrementing the frame length count K times;
• 5) waiting V byte transfer periods, wherein V equals the interrupt boundary byte count minus K;
• and
• 6) repeating steps 3), 4) and 5) until the frame length count is equal to zero.

A method for demultiplexing frames of packetized high priority data and low priority data, the low priority data packed into a hybrid frame in interrupt boundary byte count (IBBC) increments, the method comprising the steps of:

• a. determining a frame length, Fn;
• b. setting a frame length counter to Fn;
• c. reading an identification byte;
• d. decoding the identification byte to determine whether high priority or low priority data is being received;
• e. if low priority data is being received, reading Y low priority data bytes and subtracting Y from the frame length counter, wherein Y is not greater than the interrupt boundary byte count;
• and
• f. if high priority data is being received:
• 1. determining a length of the high priority data, X;
• 2. reading X bytes of high priority data;
• 3. subtracting X from the frame length counter;
• and
• 4. if the frame length counter is a positive, nonzero number, continuing to demultiplex at step c, else terminating the demultiplex.

An apparatus for multiplexing low priority data and high priority data comprising:

• aggregate module means for multiplexing high priority and low priority data;
• low priority packet module means for transceiving low priority data;
• low priority common memory means, connected to the low priority packet module means and the aggregate module means, for buffering low priority data transceived by the aggregate module means and the low priority packet module means;
• high priority packet module means for transceiving high priority data;
• and
• high priority common memory means, connected to the high priority packet module means and the aggregate module means, for buffering low priority data transceived by the aggregate module means and the high priority packet module means.

An apparatus for multiplexing low priority data and high priority data comprising:

• an aggregate module for multiplexing high priority and low priority data;
• a low priority packet module for transceiving low priority data;
• a low priority common memory, connected to the low priority packet module and the aggregate module, for buffering low priority data transceived by the aggregate module and the low priority packet module;
• a high priority packet module for transceiving high priority data;
• and
• a high priority common memory, connected to the high priority packet module and the aggregate module, for buffering low priority data transceived by the aggregate module and the high priority packet module.

A method for multiplexing high priority data, intermediate priority data, and low priority data for transmission across a communications link, the link having a maximum bandwidth with a byte transfer period equal to an amount of time needed to transfer one byte of data over the communications link, the method comprising the steps of:

• a. determining a high priority packet time;
• b. determining a maximum number of bytes transferred in one high priority packet time;
• c. determining a worst case number of high priority data bytes transferred in one high priority packet time;
• d. subtracting the worst case number of high priority bytes from the maximum number of bytes to obtain an interrupt boundary byte count;
• e. storing high priority data in a first memory, intermediate priority data in a second memory, and low priority data in a third memory;
• and
• f. multiplexing high priority data, intermediate priority data, and low priority data, wherein the step of multiplexing comprises the substeps of:
• 1. if there is high priority data, transmitting the high priority data, including a final high priority data byte;
• 2. transmitting J bytes of intermediate priority data and low priority data, wherein J is not greater than the interrupt boundary byte count;
• 3. waiting N byte transfer periods, wherein N equals the interrupt boundary byte count minus J;
• and
• 4. returning to step 1.