Use Your Frequency Wisely: Explore Frequency Domain for Channel Contention and ACK
The promise of high speed (over 1Gbps) wireless transmission rate at the physical layer can be significantly compromised with the current design of 802.11 DCF. There are three overheads in the 802.11 MAC that contribute to the performance degradation: DIFS, random backoff and ACK. Motivated by the recent progress in OFDM and self-interference cancellation technologies, in this paper, the authors propose a novel MAC design called REPICK (REversed contention and PIggy-backed ACK) to collectively address all the three overheads. The key idea in their proposal is to take advantage of OFDM subcarriers in the frequency domain to enhance the MAC efficiency.