No abstract

Inferring the quality of streaming video applications is important for Internet service providers, but the fact that most video streams are encrypted makes it difficult to do so. We develop models that infer quality metrics (\ie, startup delay and resolution) for encrypted streaming video services. Our paper builds on previous work, but extends it in several ways. First, the models work in deployment settings where the video sessions and segments must be identified from a mix of traffic and the time precision of the collected traffic statistics is more coarse (\eg, due to aggregation). Second, we develop a single composite model that works for a range of different services (\ie, Netflix, YouTube, Amazon, and Twitch), as opposed to just a single service. Third, unlike many previous models, our models perform predictions at finer granularity (\eg, the precise startup delay instead of just detecting short versus long delays) allowing to draw better conclusions on the ongoing streaming quality. Fourth, we demonstrate the models are practical through a 16-month deployment in 66 homes and provide new insights about the relationships between Internet "speed'' and the quality of the corresponding video streams, for a variety of services; we find that higher speeds provide only minimal improvements to startup delay and resolution.

Exploration and mapping is a fundamental capability of a swarm of robots: robots enter an unknown area, explore it, and collectively build a map of it. This capability is important regardless of whether the robots are crawling, flying, or swimming. Existing exploration and mapping algorithms tend to either be inefficient, or rely on having a dense swarm of robots. This paper introduces Atlas, an exploration and mapping algorithm for sparse swarms of robots, which completes a full exploration even in the extreme case of a single robot. We develop an open-source simulator and show that Atlas outperforms the state-of-the-art in terms of exploration speed and completeness of the resulting map.

No abstract

The increasing composition of mobile devices and mobile applications in the Internet requires us to revisit the traditional principles of fixed, host-centric communications, when designing a next-generation architecture. To support this major shift, we define in this paper a set of basic service abstractions that should be afforded by a future Internet that is centered upon the notion of self-certifying globally unique IDs (GUID) for all network principals -hosts, content, services, etc. alike. We followup with a specific set of network service APIs that provide full access to the proposed abstractions, and implement these on Linux and Android hosts that connect to an instantiation of the future Internet architecture proposal -MobilityFirst [5]. Using performance benchmarks and the implementation of representative use cases we show that the API is flexible and can enable efficient and robust versions of present and future applications.