Patent ID: 7177371

Claim:
A method of transmitting data over a communication network comprising: (a) dividing the data into a plurality of distinct data streams, (b) modulating each data stream into a single transmission signal at different respective modulation levels, (c) transmitting the signal, and (d) including keeping a record of acknowledgements or retransmission requests from particular terminal for a first portion of data and subsequent portions destined for the particular terminal, and periodically revising the modulation level used for data transmissions to the particular terminal based at least on the record of acknowledgements or retransmission requests, wherein the record of acknowledgements or retransmission requests is used to produce a representation N of the number of data portions in a continuous sequence of successfully received data portions which is uninterrupted by data portions which have failed to be received and wherein the method includes considering using a lower modulation level for subsequent transmissions to the particular terminal when N has reached a predetermined threshold value; wherein the predetermined threshold value for N is chosen using the formula N - ( 1 E ) - 1 where E is an error rate approximation, and N is the number of data portions in a continuous sequence of successfully received data portions which is uninterrupted by data portions which have failed to be received.