Listen (on the Frequency Domain) Before You Talk
Conventional WiFi networks perform channel contention in time domain. This is known to be wasteful because the channel is forced to remain idle, while all contending nodes are backing off for multiple time slots. This paper proposes to break away from convention and recreate the backing off operation in the frequency domain. The basic idea is to pretend that OFDM subcarriers are integer numbers, and thereby, view today's random backoff process as equivalent to transmitting on a randomly chosen subcarrier. By employing a second antenna to listen to all the subcarriers, each node can determine whether its chosen integer (or subcarrier) is the smallest among all others.