53,336 research outputs found
A Cross-Layer Descent Approach for Resilient Network Operations of Proliferated LEO Satellites
With the proliferated low-Earth-orbit (LEO) satellites in
mega-constellations, the future Internet will be able to reach any place on
Earth, providing high-quality services to everyone. However, high-quality
operations in terms of timeliness and resilience are lacking in the current
solutions. This paper proposes a multi-layer networking approach called
"Cross-Layer Descent (CLD)". Based on the proposed system model, principles,
and measures, CLD can support foundational services such as telecommand (TC)
transmissions for various network operation missions for LEO satellites
compliant with the Consultative Committee for Space Data Systems (CCSDS)
standards. The CLD approach enhances timing and resilience requirements using
advanced communication payloads. From the simulation-based analysis, the
proposed scheme outperforms other classical ones in resilience and latency for
typical TC missions. The future work and conclusive remarks are discussed at
the end.Comment: 2023 IEEE Wireless Communications and Networking Conference (WCNC),
26--29 March 2023, Glasgow, U
A Survey on Multimedia-Based Cross-Layer Optimization in Visual Sensor Networks
Visual sensor networks (VSNs) comprised of battery-operated electronic devices endowed with low-resolution cameras have expanded the applicability of a series of monitoring applications. Those types of sensors are interconnected by ad hoc error-prone wireless links, imposing stringent restrictions on available bandwidth, end-to-end delay and packet error rates. In such context, multimedia coding is required for data compression and error-resilience, also ensuring energy preservation over the path(s) toward the sink and improving the end-to-end perceptual quality of the received media. Cross-layer optimization may enhance the expected efficiency of VSNs applications, disrupting the conventional information flow of the protocol layers. When the inner characteristics of the multimedia coding techniques are exploited by cross-layer protocols and architectures, higher efficiency may be obtained in visual sensor networks. This paper surveys recent research on multimedia-based cross-layer optimization, presenting the proposed strategies and mechanisms for transmission rate adjustment, congestion control, multipath selection, energy preservation and error recovery. We note that many multimedia-based cross-layer optimization solutions have been proposed in recent years, each one bringing a wealth of contributions to visual sensor networks
Practical issues for the implementation of survivability and recovery techniques in optical networks
Ideological and Temporal Components of Network Polarization in Online Political Participatory Media
Political polarization is traditionally analyzed through the ideological
stances of groups and parties, but it also has a behavioral component that
manifests in the interactions between individuals. We present an empirical
analysis of the digital traces of politicians in politnetz.ch, a Swiss online
platform focused on political activity, in which politicians interact by
creating support links, comments, and likes. We analyze network polarization as
the level of intra- party cohesion with respect to inter-party connectivity,
finding that supports show a very strongly polarized structure with respect to
party alignment. The analysis of this multiplex network shows that each layer
of interaction contains relevant information, where comment groups follow
topics related to Swiss politics. Our analysis reveals that polarization in the
layer of likes evolves in time, increasing close to the federal elections of
2011. Furthermore, we analyze the internal social network of each party through
metrics related to hierarchical structures, information efficiency, and social
resilience. Our results suggest that the online social structure of a party is
related to its ideology, and reveal that the degree of connectivity across two
parties increases when they are close in the ideological space of a multi-party
system.Comment: 35 pages, 11 figures, Internet, Policy & Politics Conference,
University of Oxford, Oxford, UK, 25-26 September 201
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