Strong framing protocol for HDLC and other run-length codes

Ideal for use in high-speed wide-area networks, such as HDLC as defined in ISO Standard 3309, a strong framing method for data packets significantly improves undetected error probability. In a run-length code type data communication scheme, wherein frame delimiter strings, abort strings and idle strings, are transmitted as control symbols, the method includes providing the frame delimiter string as a multi-symbol construct for delimiting the transmitted data, providing the abort strings and idle strings to respectively include minimum run lengths which are substantially longer than the individual symbols in the multi-symbol construct, transmitting data with control symbols as a bit sequence, and receiving and analyzing the transmitted data at the data-receiving device to detect the presence of bit errors.