Mobile and Cellular Networks from the Edge

Sat, 01 Nov 2014 00:00:00 +0000

Project Overview

For most people on Earth, the Internet is reached over a cellular network. Yet cellular infrastructure is among the hardest of all networks to observe: the interesting behaviour happens inside operator networks that publish little, use private addressing, and terminate traffic at gateways whose location bears no simple relation to the user’s.

The consistent move in this thread is to measure from the client, where a handset can see what an outside prober cannot, and to keep asking a question that outsiders usually assume away: for a mobile user, where is the network actually, and what does that cost?

Cellular Networks in the Internet

Cell Spotting mapped where cellular traffic enters the Internet, showing that the gateways serving mobile users are far more concentrated and far less local than the geography of their users implies. Behind the Curtain followed the consequence into content delivery: if a CDN sees a query arriving from a distant gateway, the replica it picks is wrong for the user holding the phone — the same problem our DNS work had found on fixed lines, sharper in cellular.

Anycast on the Move asked what happens to anycast routing when the client itself is moving, and Where Things Roam turned to cellular IoT and M2M connectivity, a population of devices that roams permanently by design.

Aggregators and Roaming

Roaming is no longer a bilateral arrangement between two operators. A layer of global aggregators now sits between the SIM and the networks that serve it, which changes the performance a device gets and makes the path it takes hard for anyone to predict. Our MobiSys paper laid out a taxonomy of these aggregators and measured their roaming performance and optimization, and the later TNSM article extends the comparison.

The Mobile Web

Mobile web performance has been shaped as much by intermediaries as by protocols. AMP up your Mobile Web Experience characterized what Google’s Accelerated Mobile Pages actually delivers, separating the gains attributable to the format from those attributable to serving from Google’s cache. Reining in Mobile Web Performance looked at what document and permission policies can recover, and Mobile AD(D) examined app session times, which determine what an ad — or any load — is worth paying for.

Connectivity in Motion

In-flight Internet is a useful extreme case: a satellite path, a shared cell with a hundred passengers, and a network stack designed for none of it. Mile High WiFi was a first look at in-flight connectivity in the wild, and When IPs Fly made the case for rethinking airline communication rather than treating the aircraft as an ordinary subscriber.

Papers

Cellular networks in the Internet

Behind the Curtain – Cellular DNS and Content Replica Selection — IMC 2014
Behind the Curtain: The Importance of Replica Selection in Next Generation Cellular Networks — SIGCOMM 2014 (poster)
Cell Spotting: Studying the Role of Cellular Networks in the Internet — IMC 2017
Anycast on the Move: A Look at Mobile Anycast Performance — TMA 2018
Where Things Roam: Uncovering Cellular IoT/M2M Connectivity — IMC 2020

Aggregators and roaming

Global Mobile Network Aggregators: Taxonomy, Roaming Performance and Optimization — MobiSys 2022
A Comparative Analysis of Global Mobile Network Aggregators — IEEE TNSM, 2025

The mobile web

Mobile AD(D): Estimating Mobile App Session Times for Better Ads — HotMobile 2015
AMP up your Mobile Web Experience — MobiCom 2019
Reining in Mobile Web Performance with Document and Permission Policies — HotMobile 2022

Connectivity in motion

When IPs Fly: A Case for Redefining Airline Communication — HotMobile 2016
Mile High WiFi: A First Look at In-Flight Internet Connectivity — WWW 2018

Coverage

In-flight WiFi — Northwestern McCormick News, ChicagoInno, and the Chicago Tribune (2016)
The in-flight browsing extension — Network World, New Atlas, ScienceDaily, CACM News, Indian Express, and Travel+Leisure (2017)
Phone usage — Northwestern McCormick News and ACM TechNews (2016)

People

Lead & PI

Fabián E. Bustamante (Northwestern University)

Students

Collaborators

Andra Lutu (Telefónica Research)
Sergi Alcalá-Marín, Marcelo Bagnulo (Universidad Carlos III de Madrid)
Özgü Alay (University of Oslo)
Moritz Steiner (Akamai)
Vishnu Navda, Ranjita Bhagwan, Saikat Guha (Microsoft Research India)

Cellular | Aqualab - Northwestern University