Sorry for the late reply. Thank you for your interest in our work! And also thank you so much for providing the pointers on related literature! They are really helpful and we will look into these work later.

We did simulate the FqCoDel using the built-in implementation of ns-3. Two of the issues that we found are that (i) some CCAs are not responsive to packet losses, especially for latency-sensitive CCAs -- GCC seems to need a loss rate of >10% to trigger the loss controller; and (ii) if the CCA on the sender is not ECN-compatible, additional packet retransmissions will further occupy the buffer space, leading to longer duration of congestion.

We did not compare FqCoDel in the testbed experiments on WiFi AP due to the reasons above. We do hope to test with more cases and baselines in the real implementations in the future.

If there are any further questions, please do not hesitate to contact us. Thank you!