Cellular networks serve as the backbone of global communication, providing critical access to telephony and the Internet, often in regions lacking alternatives. However, the growing complexity of these networks, driven by architectural innovations (e.g., Voice over IP, eSIMs) and commercial dynamics (e.g., roaming, virtual operators, zero-rating), remains poorly understood due to the lack of open, scalable, and geographically diverse measurement tools and independent measurement studies. Moreover, access to mobile networks today is no longer limited to the traditional radio interface. Technologies like Voice-over-WiFi (VoWiFi) offer alternative connectivity paths via third-party Internet infrastructure, extending operator reach into environments with limited cellular coverage. At the same time, over-the-top (OTT) messaging services such as WhatsApp and Signal have become central to modern communication, accounting for a substantial share of global messaging and voice traffic while bypassing traditional operator-controlled channels entirely. This dissertation addresses these challenges by introducing new approaches for independent, scalable, and reproducible measurements of mobile communication systems without requiring cooperation from network or platform operators. We design, implement, and open-source measurement platforms that enable controlled experiments across cellular radio networks, operator-provided services, and OTT messaging applications.

翻译：蜂窝网络作为全球通信的支柱，在缺乏替代方案的地区提供电话和互联网的关键接入。然而，由于缺乏开放、可扩展且地理多样化的测量工具及独立测量研究，由架构创新（如IP语音、eSIM）和商业动态（如漫游、虚拟运营商、零费率）驱动的网络日益复杂性仍难以被充分理解。此外，当前对移动网络的接入已不再局限于传统无线电接口。VoWiFi（语音WiFi）等技术通过第三方互联网基础设施提供替代连接路径，将运营商覆盖范围扩展至蜂窝信号有限的区域。与此同时，WhatsApp和Signal等OTT即时通讯服务已成为现代通信的核心，占据全球消息和语音流量的相当大份额，同时完全绕过了传统运营商控制的信道。本论文通过引入新方法来解决这些挑战，这些方法可在无需网络或平台运营商配合的情况下，对移动通信系统进行独立、可扩展且可重现的测量。我们设计、实现并开源了测量平台，支持在蜂窝无线网络、运营商提供的服务以及OTT消息应用中进行受控实验。