New results on the real-time transmission problem

A new concept is presented for the treatment of real-time transmission problems. It basically consists of a modification of the flow of information. The resulting quantity, which we call the forward flow of information, is smaller than the flow of information according to the usual definition except for special cases. We derive various negative coding theorems in which the forward flow of information is used. These bounds are sharper than those previously known for transmission with finite delay.