The millimeter wave (mmWave) bands are likely to play a significant role in
next generation cellular systems due to the possibility of very high throughput
thanks to the availability of massive bandwidth and high-dimensional antennas.
Especially in Non-Line-of-Sight conditions, significant variations in the
received RF power can occur as a result of the scattering from nearby building
and terrain surfaces. Scattering objects come and go as the user moves through
the local environment. At the higher end of the mmWave band, rough surface
scatter generates cluster-based small-scale fading, where signal levels can
vary by more than 20 dB over just a few wavelengths. This high level of channel
variability may present significant challenges for congestion control. Using
our recently developed end-to-end mmWave ns3-based framework, this paper
presents the first performance evaluation of TCP congestion control in
next-generation mmWave networks. Importantly, the framework can incorporate
detailed models of the mmWave channel, beam- forming and tracking algorithms,
and builds on statistical channel models derived from real measurements in New
York City, as well as detailed ray traces