High-speed rail (HSR) systems potentially provide a more efficient way of door-to-door transportation than airplane. However, they also pose unprecedented challenges in delivering seamless Internet service for on-board passengers. In this paper, we conduct the first large-scale disconnection-centric measurement study of TCP performance over LTE on HSR. Our measurement targets the main HSR route in China operating at 300/350 km/h. We performed extensive data collection obtaining 378.3 GB data collected over 56639 km of trips. Leveraging such a unique dataset, we measure important performance metrics such as TCP goodput, latency and loss rate across different congestion control algorithm, mobile carrier, and different train speed. We further develop the LTE disconnection taxonomy, and conduct a in-depth correlation study between TCP stall and LTE disconnection. Our findings reveal the networking performance on today's HSR environment 'in the wild', as well as identify several root causes of performance inefficiencies, which together highlight the need to develop dedicated protocol mechanisms that are friendly to extreme mobility.
Bibliographical noteFunding Information:
Manuscript received December 11, 2019; revised March 15, 2020; accepted April 28, 2020. Date of publication July 2, 2020; date of current version November 20, 2020. This work was supported in part by the National Key Research and Development Plan, China under Grant 2016YFB1001200, in part by the National Natural Science Foundation of China under Grant 61802007, in part by the 111 Project under Grant B14025, and in part by Microsoft Research Asia. (Corresponding author: Chenren Xu.) Chenren Xu, Jing Wang, Zhiyao Ma, Yihua Cheng, and Yunzhe Ni are with the Department of Computer Science and Technology, Peking University, Beijing 100871, China (e-mail: email@example.com).
- LTE disconnection
- TCP stall
- high mobility
- high-speed railway