Channel decoding makes use of redundancy in the coded bits. However, any redundancy in the information bitstream can also improve the decoding process. This paper shows that a careful examination of communication standards (including the headers added by the network layers) exhibits some fields which can be considered as redundant, either based on already received packets, or on the standard. The efficient use of this knowledge in the channel decoding process is denoted as protocol-assisted channel decoding. Assuming perfect synchronization and available channel state information, the proposed method applied on 802.11a PHY and MAC layers provides a substantial link budget improvement without modifying the standard, while the introduction of an additional interleaver provides additional bit error rate improvements.