  Due to massive available spectrum in the millimeter wave (mmWave) bands,
cellular systems in these frequencies may provides orders of magnitude greater
capacity than networks in conventional lower frequency bands. However, due to
high susceptibility to blocking, mmWave links can be extremely intermittent in
quality. This combination of high peak throughputs and intermittency can cause
significant challenges in end-to-end transport-layer mechanisms such as TCP.
This paper studies the particularly challenging problem of bufferbloat.
Specifically, with current buffering and congestion control mechanisms, high
throughput-high variable links can lead to excessive buffers incurring long
latency. In this paper, we capture the performance trends obtained while
adopting two potential solutions that have been proposed in the literature:
Active queue management (AQM) and dynamic receive window. We show that, over
mmWave links, AQM mitigates the latency but cannot deliver high throughput. The
main reason relies on the fact that the current congestion control was not
designed to cope with high data rates with sudden change. Conversely, the
dynamic receive window approach is more responsive and therefore supports
higher channel utilization while mitigating the delay, thus representing a
viable solution.
