221 research outputs found

    Network layer solutions for a content-centric internet

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    Nowadays most people exploit the Internet to get contents such as web pages, music or video files. These users only value “what” they download and are not interested about “where” content is actually stored. The IP layer does the opposite and cares about the “where” and not about the “what”. This contrast between the actual usage of the Internet and the service offered by the IP layer is deemed to be the source of several problems concerning usability, performance, security and mobility issues. To overcome this contrast, research on the Future Internet is exploring novel so-called content-centric architectures, where the network layer directly provides users with contents, instead of providing communication channels between hosts. In this paper, we identify the main functionalities of a content-centric network (CONET), we discuss pros and cons of literature proposals for an innovative, content-centric network layer and we draw our conclusions, stating some general requirements that, in our opinion, a CONET should satisfy

    Will the Proliferation of 5G Base Stations Increase the Radio-Frequency 'Pollution'?

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    A common concern among the population is that installing new 5G Base Stations (BSs) over a given geographic region may result in an uncontrollable increase of Radio-Frequency 'Pollution' (RFP). To face this dispute in a way that can be understood by the layman, we develop a very simple model, which evaluates the RFP at selected distances between the user and the 5G BS locations. We then obtain closed-form expressions to quantify the RFP increase/decrease when comparing a pair of alternative 5G deployments. Results show that a dense 5G deployment is beneficial to the users living in proximity to the 5G BSs, with an abrupt decrease of RFP (up to three orders of magnitude) compared to a sparse deployment. We also analyze scenarios where the user equipment minimum detectable signal threshold is increased, showing that in such cases a (slight) increase of RFP may be experienced

    Streaming H.264 scalable video over data distribution service in a wireless environment

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    The Data Distribution Service (DDS) middleware is enjoying a rapid adoption in high-performance, mission-critical networks. At the same time, the H.264 Scalable Video Coding (SVC) has been recently standardized and it is deemed to be an effective solution for video streaming over a channel with time-varying bandwidth, like the wireless one. In these conditions, it is critical to adapt the video bit-rate to the actual wireless capacity, and bit-rate adaptation is extremely simple for a H.264 SVC video. In this paper we devise, evaluate and demonstrate a technique for streaming H.264 SVC video over a DDS middleware. The contribution is threefold: i) we design a structure of the DDS data-unit able to carry H.264 SVC video-units; ii) we devise a receiver-driven rate-control mechanism based on our DDS data-unit and exploiting specific DDS functionality; iii) we implement and show the effectiveness of our mechanism in an 802.11 wireless scenario, comparing our proposal with other solution

    Is It Safe Living in the Vicinity of Cellular Towers? Analysis of Long-Term Human EMF Exposure at Population Scale

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    We focus on the ElectroMagnetic Field (EMF) exposure safety for people living in the vicinity of cellular towers. To this aim, we analyze a large dataset of long-term EMF measurements collected over almost 20 years in more than 2000 measurement points spread over an Italian region. We evaluate the relationship between EMF exposure and the following factors: (i) distance from the closest installation(s), (ii) type of EMF sources in the vicinity, (iii) Base Station (BS) technology, and (iv) EMF regulation updates. Overall, the exposure levels from BSs in the vicinity are below the Italian EMF limits, thus ensuring safety for the population. Moreover, BSs represent the lowest exposure compared to Radio/TV repeaters and other EMF sources. However, the BS EMF exposure in proximity to users exhibits an increasing trend over the last years, which is likely due to the pervasive deployment of multiple technologies and to the EMF regulation updates. As a side consideration, if the EMF levels continue to increase with the current trends, the EMF exposure in proximity to BSs will saturate to the maximum EMF limit by the next 20 years at a distance of 30 meters from the closest BS

    Check before storing: what is the performance price of content integrity verification in LRU caching?

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    In some network and application scenarios, it is useful to cache content in network nodes on the ïŹ‚y, at line rate. Resilience of in-network caches can be improved by guaranteeing that all content therein stored is valid. Digital signatures could be indeed used to verify content integrity and provenance. However, their operation may be much slower than the line rate, thus limiting caching of cryptographically veriïŹed objects to a small subset of the forwarded ones. How this aïŹ€ects caching performance? To answer such a question, we devise a simple analytical approach which permits to assess performance of an LRU caching strategy storing a randomly sampled subset of requests. A key feature of our model is the ability to handle traïŹƒc beyond the traditional Independent Reference Model, thus permitting us to understand how performance vary in diïŹ€erent temporal locality conditions. Results, also veriïŹed on real world traces, show that content integrity veriïŹcation does not necessarily bring about a performance penalty; rather, in some speciïŹc (but practical) conditions, performance may even improve

    'Pencil Beamforming Increases Human Exposure to ElectroMagnetic Fields': True or False?

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    According to a very popular belief-very widespread among non-scientific communities-the exploitation of narrow beams, a.k.a. 'pencil beamforming', results in a prompt increase of exposure levels radiated by 5G Base Stations (BSs). To face such concern with a scientific approach, in this work we propose a novel localization-enhanced pencil beamforming technique, in which the traffic beams are tuned in accordance with the uncertainty localization levels of User Equipment (UE). Compared to currently deployed beamforming techniques, which generally employ beams of fixed width, we exploit the localization functionality made available by the 5G architecture to synthesize the direction and the width of each pencil beam towards each served UE. We then evaluate the effectiveness of pencil beamforming in terms of ElectroMagnetic Field (EMF) exposure and UE throughput levels over different realistic case-studies. Results, obtained from a publicly released open-source simulator, dispel the myth: the adoption of localization-enhanced pencil beamforming triggers a prompt reduction of exposure w.r.t. other alternative techniques, which include e.g., beams of fixed width and cellular coverage not exploiting beamforming. The EMF reduction is achieved not only for the UE that are served by the pencil beams, but also over the whole territory (including the locations in proximity to the 5G BS). In addition, large throughput levels-adequate for most of 5G services-can be guaranteed when each UE is individually served by one dedicated beam

    Massive measurements of 5G exposure in a town: methodology and results

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    We target the problem of performing a large set of measurements over the territory to characterize the exposure from a 5G deployment. Since using a single Spectrum Analyzer (SA) is not practically feasible (due to the limited battery duration), in this work we adopt an integrated approach, based on the massive measurement of 5G metrics with a 5G smartphone, followed by a detailed analysis done with the SA and an ElectroMagnetic Field (EMF) meter in selected locations. Results, obtained over a real territory covered by 5G signal, reveal that 5G exposure is overall very limited for most of measurement locations, both in terms of field strength (up to 0.7 [V/m]) and as share w.r.t. other wireless technologies (typically lower than 15%). Moreover, our approach allows easily spotting measurement outliers, e.g., due to the exploitation of Dynamic Spectrum Sharing (DSS) techniques between 4G and 5G. In addition, the exposure metrics collected with the smartphone are overall a good proxy of the total exposure measured over the whole 5G channel. Moreover, the sight conditions and the distance from 5G base station play a great role in determining the level of exposure. Finally, a maximum of 130 [W] of power radiated by a 5G base station is estimated in the scenario under consideration

    The simplicity project: easing the burden of using complex and heterogeneous ICT devices and services

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    As of today, to exploit the variety of different "services", users need to configure each of their devices by using different procedures and need to explicitly select among heterogeneous access technologies and protocols. In addition to that, users are authenticated and charged by different means. The lack of implicit human computer interaction, context-awareness and standardisation places an enormous burden of complexity on the shoulders of the final users. The IST-Simplicity project aims at leveraging such problems by: i) automatically creating and customizing a user communication space; ii) adapting services to user terminal characteristics and to users preferences; iii) orchestrating network capabilities. The aim of this paper is to present the technical framework of the IST-Simplicity project. This paper is a thorough analysis and qualitative evaluation of the different technologies, standards and works presented in the literature related to the Simplicity system to be developed
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