The paper presents an experiment-based characterization of passive suppression and active self-interference cancellation mechanisms in full-duplex wireless communication systems. The authors consider passive suppression due to antenna separation and active cancellation in analog and/or digital domains. They find that the average amount of cancellation increases as the received self-interference power increases, and show that for a constant signal-to-interference ratio (SIR) at the receiver antenna, the rate of a full-duplex link increases with self-interference power. They also demonstrate that applying digital cancellation after analog cancellation can sometimes increase self-interference, making it more effective when selectively applied based on measured suppression values. Additionally, they characterize the probability distribution of the self-interference channel before and after cancellation. The study includes a detailed analysis of the impact of different self-interference cancellation mechanisms on the performance of full-duplex wireless communication systems, with a focus on the achievable rate performance in two-way full-duplex systems. The results highlight the importance of combining passive suppression and active cancellation to achieve higher rates and provide insights into the design of optimal training for computation of cancellation coefficients.The paper presents an experiment-based characterization of passive suppression and active self-interference cancellation mechanisms in full-duplex wireless communication systems. The authors consider passive suppression due to antenna separation and active cancellation in analog and/or digital domains. They find that the average amount of cancellation increases as the received self-interference power increases, and show that for a constant signal-to-interference ratio (SIR) at the receiver antenna, the rate of a full-duplex link increases with self-interference power. They also demonstrate that applying digital cancellation after analog cancellation can sometimes increase self-interference, making it more effective when selectively applied based on measured suppression values. Additionally, they characterize the probability distribution of the self-interference channel before and after cancellation. The study includes a detailed analysis of the impact of different self-interference cancellation mechanisms on the performance of full-duplex wireless communication systems, with a focus on the achievable rate performance in two-way full-duplex systems. The results highlight the importance of combining passive suppression and active cancellation to achieve higher rates and provide insights into the design of optimal training for computation of cancellation coefficients.