[nuand]

OFDM 802.11 rates already have a significant amount of Forward Error Correction. 802.11g uses a convolution encoder and Viterbi Decoder [1], and 802.11 HT rates (n, ac, ad) can also use Low Density Parity Codes (LDPC) [2]. The problem with Forward Error Correction is that it can't deal with too many sequential errors, so many modems use something known as an interleaver. An reorders bits as they are sent over the air, so instead of sending LSB to MSB or vice versa you are sending bits in a random yet mutually known order. This causes link quality issues such as interference to not interfere with continuous bits (to the benefit of the FEC decoder). The problem with an interleaver is that it causes latency to go up. If you interleave based on 256 bits of 2048bits, you can't decode blocks of data until you've received all of this bits. So the 288 bit interleaver that 802.11 uses won't cause many problems if you're streaming but if you are interleaving data across multiple packets you will notice a spike in video latency.

[1] https://en.wikipedia.org/wiki/Viterbi_algorithm [2] https://en.wikipedia.org/wiki/Low-density_parity-check_code