Parallel (Viterbi)

• Constant decode time
• Limited constraint length - complexity O(2^k)

• Well suited for hardware implementation - chips commercially available
• Best for channels limited by thermal or thermal-like noise, e.g., satellite or spread spectrum

Sequential (Fano, Stack)

• Variable decoding time, depends on error rate; either faster or slower than Viterbi
• Allows very long constraint lengths (k = 32 common)

• With k large, nil probability of incorrect decode (timeout more likely)
• Good for software implementation, especially when error rate is low