Will TCP work in mmWave 5G Cellular Networks?

TL;DR

This paper investigates the effectiveness of TCP in mmWave 5G networks, highlighting the challenges posed by intermittent links and analyzing how various factors influence TCP performance through comprehensive simulations.

Contribution

It provides a detailed simulation-based analysis of TCP performance in mmWave 5G, considering multiple parameters and identifying key open challenges.

Findings

TCP performance varies significantly with different congestion control algorithms.

Handover and multi-connectivity impact TCP stability in mmWave networks.

Open challenges remain in optimizing TCP for highly variable mmWave links.

Abstract

The vast available spectrum in the millimeter wave (mmWave) bands offers the possibility of multi-Gbps data rates for fifth generation (5G) cellular networks. However, mmWave capacity can be highly intermittent due to the vulnerability of mmWave signals to blockages and delays in directional searching. Such highly variable links present unique challenges for adaptive control mechanisms in transport layer protocols and end-to-end applications. This paper considers the fundamental question of whether TCP - the most widely used transport protocol - will work in mmWave cellular systems. The paper provides a comprehensive simulation study of TCP considering various factors such as the congestion control algorithm, including the recently proposed TCP BBR, edge vs. remote servers, handover and multi- connectivity, TCP packet size and 3GPP-stack parameters. We show that the performance of TCP on mmWave links is highly dependent on different combinations of these parameters, and identify the open challenges in this area.