Methods and systems for encoding a frame utilizing at least two line-codes having different minimal Hamming distances. The method includes maintaining over the frame absolute value of running disparity lower than or equal to K, while: encoding a first part of the frame utilizing a first line-code having a binary code word length N′ and a minimal Hamming distance D′; and encoding a second part of the frame utilizing a second line-code having a binary code word length N″ and a minimal Hamming distance D″ lower than D′. Where the value of K is lower than both N′/2 and N″/2.