WiFi-Nano: Reclaiming WiFi Efficiency Through 800 Ns Slots
The increase in WiFi physical layer transmission speeds from1 Mbps to 1 Gbps has reduced transmission times for a 1500 byte packet from 12 ms to 12 ?s. However, WiFi MAC overheads such as channel access and acks have not seen similar reductions and cumulatively contribute about 150 ?s on average per packet. Thus, the efficiency of WiFi has deteriorated from over 80% at 1 Mbps to under 10% at 1 Gbps. In this paper, the authors propose WiFi-Nano, a system that uses 800 ns slots to significantly improve WiFi efficiency. Reducing slot time from 9 ?s to 800 ns makes backoffs efficient, but clear channel assessment can no longer be completed in one slot since preamble detection can now take multiple slots.