Current wireless protocols retransmit any packet that fails the 
checksum test, even when most of the bits are correctly received.
Prior work has recognized this inefficiency, however the proposed 
solutions (e.g., PPR, HARQ and SOFT) require changes to the hardware 
and physical layer, and hence are not usable in today WLANs and mesh 
networks. We introduce ZipTx, a new driver that improves the 
throughput of existing WLAN and mesh networks by exploiting the 
correctly received bits in corrupted packets. ZipTx differs from 
current drivers in three main ways: 1) instead of throwing away 
corrupted packets, it retains them and tries to correct their faulty 
bits; 2) it progressively transmits parity bits, allowing it to 
correct faulty packets without any information from the hardware 
about which bits are in error; and 3) it modifies the autorate 
algorithm to  account for partially received packets, allowing it 
to push to higher bit rates while still running reliably. We 
experiment with our ZipTx implementation in both outdoor and indoor 
environments, showing that ZipTx significantly improves the 
throughput.