IMDEA Networks Institute Digital Repository
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Apps, Trackers, Privacy, and Regulators: A Global Study of the Mobile Tracking Ecosystem
Get PDFThird-party services form an integral part of the mobile ecosystem: they ease application development and enable features such as analytics, social network integration, and app monetization through ads. However, aided by the general opacity of mobile systems, such services are also largely invisible to users. This has negative consequences for user privacy as third-party services can potentially track users without their consent, even across multiple applications. Using real-world mobile traffic data gathered by the Lumen Privacy Monitor (Lumen), a privacy enhancing app with the ability to analyze network traffic on mobile devices in user space, we present insights into the mobile advertising and tracking ecosystem and its stakeholders. In this study, we develop automated methods to detect third-party advertising and tracking services at the traffic level. Using this technique we identify 2,121 such services, of which 233 were previously unknown to other popular advertising and tracking blacklists. We then uncover the business relationships between the providers of these services and characterize them by their prevalence in the mobile and Web ecosystem. Our analysis of the privacy policies of the largest advertising and tracking service providers shows that sharing harvested data with subsidiaries and third-party affiliates is the norm. Finally, we seek to identify the services likely to be most impacted by privacy regulations such as the European General Data Protection Regulation (GDPR) and ePrivacy directives.TRUEpu
Demo: Electrosense - Spectrum Sensing with Increased Frequency Range
Get PDFThis demo introduces an expansion board for Electrosense, a system for crowdsourced spectrum monitoring and analysis. The first generation of Electrosense sensor nodes, was based on a low cost Software Defined Radio (SDR) dongle with a frequency range limited to 24 MHz - 1.7 GHz. The new generation adds a custom made down-converter that extends the capabilities of the SDR dongle, enabling spectrum monitoring from almost DC up to 6 GHz. The low cost of the proposed sensor nodes allows for a large scale deployment which generates a massive amount of RF spectrum data. A server backend performs storage and data analysis. All the data and the results are available through an public open API. The goal of the demo is to introduce the hardware platform and illustrate how a combination of the default sensor and the expansion board can be used to flexibly scan multiple frequency bands.TRUEpu
Statistical Multiplexing and Traffic Shaping Games for Network Slicing
Get PDFNext-generation wireless architectures are expected to enable slices of shared wireless infrastructure, which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services’ spatial loads, it is highly desirable to achieve efficient statistical multiplexing among such slices. We study a simple dynamic resource sharing policy, which allocates a “share” of a pool of (distributed) resources to each slice-share constrained proportionally fair (SCPF). We give a characterization of SCPF’s performance gains over static slicing and general processor sharing. We show that higher gains are obtained when a slice’s spatial load is more “imbalanced” than, and/or “orthogonal” to, the aggregate network load, and that the overall gain across slices is positive. We then address the associated dimensioning problem. Under SCPF, traditional network dimensioning translates to a coupled share dimensioning problem, which characterizes the existence of a feasible share allocation, given slices’ expected loads and performance requirements. We provide a solution to robust share dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users’ performance via admission control, which maximizes their carried loads subject to performance requirements. We show that this can be modeled as a “traffic shaping” game with an achievable Nash equilibrium. Under high loads, the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF versus static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and the range of validity of our high-load equilibrium analysis.pu
Personal Insights on Three Research Directions in Networked Systems
Get PDFIn this work, we draw from our research and industry experience in the design of networked systems and define research directions that can simplify management and better exploit network infrastructure. We introduce problems both on data and control planes related to the design of a single network element and network-wide behaviors, concentrating on three directions: processing a single packet with packet classifiers, processing streams of packets in network switches, and network-wide control plane optimization. In particular, we consider efficient representations of packet classifiers, expressive implementations of buffer management policies, the composition of heterogeneous control planes, network virtualization, and extension of the network stack to support interactive applications. For the considered research directions outlined here, we formulate problems that, we believe, are important in the design of network systems. The purpose of this work is to attract system researchers to specific problems introduced in this paper.TRUEpu
Collaborative Data Delivery for Smart City-oriented Mobile Crowdsensing Systems
Get PDFThe huge increase of population living in cities calls for a sustainable urban development. Mobile Crowdsensing (MCS) leverages participation of active citizens to improve performance of existing sensing infrastructures. In typical MCS systems, sensing tasks are allocated and reported on individual-basis. In this paper, we investigate on collaboration among users for data delivery as it brings a number of benefits for both users and sensing campaign organizers and leads to better coordination and use of resources. By taking advantage from proximity, users can employ D2D communications like Wi-Fi Direct that are more energy efficient than 3G/4G technology. In such scenario, once a group is set, one of its member is elected to be the owner and perform data forwarding to the collector. The efficiency of forming groups and electing suitable owners defines the efficiency of the whole collaborative-based system. This paper proposes three policies optimized for MCS that are compliant with current Android implementation of Wi-Fi Direct. The evaluation results, obtained using CrowdSenSim simulator, demonstrate that collaborative-based approaches outperform significantly individual-based approaches.TRUEpu
On the energy efficiency of rate and transmission power control in 802.11
Get PDFRate adaptation and transmission power control in 802.11 WLANs have received a lot of attention from the research community, with most of the proposals aiming at maximising throughput based on network conditions. Considering energy consumption, an implicit assumption is that optimality in throughput implies optimality in energy efficiency, but this assumption has been recently put into question. In this paper, we address via analysis, simulation and experimentation the relation between throughput performance and energy efficiency in multi-rate 802.11 scenarios. We demonstrate the trade-off between these performance figures, confirming that they may not be simultaneously optimised, and analyse their sensitivity towards the energy consumption parameters of the device. We analyse this trade-off in existing rate adaptation with transmission power control algorithms, and discuss how to design novel schemes taking energy consumption into account.pu