A Fog-based Distributed Look-up Service for Intelligent Transportation Systems

Future intelligent transportation systems and applications are expected to greatly benefit from the integration with a cloud computing infrastructure for service reliability and efficiency. More recently, fog computing has been proposed as a new computing paradigm to support low-latency and location-aware services by moving the execution of application logic on devices at the edge of the network in proximity of the physical systems, e.g. in the roadside infrastructure or directly in the connected vehicles. Such distributed runtime environment can support low-latency communication with sensors and actuators thus allowing functions such as real-time monitoring and remote control, e.g. for remote telemetry of public transport vehicles or remote control under emergency situations, respectively. These applications will require support for some basic functionalities from the runtime. Among them, discovery of sensors and actuators will be a significant challenge considering the large variety of sensors and actuators and their mobility. In this paper, a discovery service specifically tailored for fog computing platforms with mobile nodes is proposed. Instead of adopting a centralized approach, we pro-pose an approach based on a distributed hash table to be implemented by fog nodes, exploiting their storage and computation capabilities. The proposed approach supports by design multiple attributes and range queries. A prototype of the proposed service has been implemented and evaluated experimentally

Exploiting LTE D2D communications in M2M Fog platforms: Deployment and practical issues

Fog computing is envisaged as the evolution of the current centralized cloud to support the forthcoming Internet of Things revolution. Its distributed architecture aims at providing location awareness and low-latency interactions to Machine-to-Machine (M2M) applications. In this context, the LTE-Advanced technology and its evolutions are expected to play a major role as a communication infrastructure that guarantees low deployment costs, plug-and-play seamless configuration and embedded security. In this paper, we show how the LTE network can be configured to support future M2M Fog computing platforms. In particular it is shown how a network deployment that exploits Device-to-Device (D2D) communications, currently under definition within 3GPP, can be employed to support efficient communication between Fog nodes and smart objects, enabling low-latency interactions and locality-preserving multicast transmissions. The proposed deployment is presented highlighting the issues that its practical implementation raises. The advantages of the proposed approach against other alternatives are shown by means of simulation

A Configurable Protocol for Quantum Entanglement Distribution to End Nodes

The primary task of a quantum repeater network is to deliver entanglement among end nodes. Most of existing entanglement distribution protocols do not consider purification, which is thus delegated to an upper layer. This is a major drawback since, once an end-to-end entangled connection (or a portion thereof) is established it cannot be purified if its fidelity (F) does not fall within an interval bounded by Fmin (greater than 0.5) and Fmax (less than 1). In this paper, we propose the Ranked Entanglement Distribution Protocol (REDiP), a connection-oriented protocol that overcomes the above drawback. This result was achieved by including in our protocol two mechanisms for carrying out jointly purification and entanglement swapping. We use simulations to investigate the impact of these mechanisms on the performance of a repeater network, in terms of throughput and fidelity. Moreover, we show how REDiP can easily be configured to implement custom entanglement swapping and purification strategies, including (but not restricted to) those adopted in two recent works.Comment: 6 pages, 6 figures, submitted to IEEE ICC 202

A reinforcement learning-based link quality estimation strategy for RPL and its impact on topology management

Over the last few years, standardisation efforts are consolidating the role of the Routing Protocol for Low-Power and Lossy Networks (RPL) as the standard routing protocol for IPv6-based Wireless Sensor Networks (WSNs). Although many core functionalities are well defined, others are left implementation dependent. Among them, the definition of an efficient link-quality estimation (LQE) strategy is of paramount importance, as it influences significantly both the quality of the selected network routes and nodesâ\u80\u99 energy consumption. In this paper, we present RL-Probe, a novel strategy for link quality monitoring in RPL, which accurately measures link quality with minimal overhead and energy waste. To achieve this goal, RL-Probe leverages both synchronous and asynchronous monitoring schemes to maintain up-to-date information on link quality and to promptly react to sudden topology changes, e.g. due to mobility. Our solution relies on a reinforcement learning model to drive the monitoring procedures in order to minimise the overhead caused by active probing operations. The performance of the proposed solution is assessed by means of simulations and real experiments. Results demonstrated that RL-Probe helps in effectively improving packet loss rates, allowing nodes to promptly react to link quality variations as well as to link failures due to node mobility

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t is common knowledge that over the last decade there has been a major boost in communication networks. In fact, the development of high-performance backbone networks was immediately followed by the rapid dissemination of broadband wired access technologies, such as leased lines based on fiber-optic links, cable modems using coaxial systems, and digital subscriber line (xDSL) access networks. This gave users a whole new class of services that exploit the increasing number of available network resources. Many new services are based on multimedia applications, such as voice over IP (VoIP), video conferencing, video on demand (VoD), massive online gaming, and peer-to-peer. Unlike traditional TCP/IP services, multimedia applications usually require strict network guarantees such as reserved bandwidth or bounded delays. The broadband access phenomenon has been investigated by the International Telecommunication Union (ITU), which reported in [1] that Broadband Wireless Access (BWA), although still in the early stage of its growth, is one of the most promising solutions for broadband access. Standards for BWA are being developed within IEEE Project 802, working group 16, also referred to as 802.16 The challenge for BWA networks is in providing quality of service (QoS) simultaneously to services with very different characteristics. QoS support in wireless networks is a much more difficult task than in wired networks, mainly because the characteristics of a wireless link are highly variable and unpredictable, both on a time-dependent basis and a locationdependent basis. To cope with such issues, QoS in wireless networks is usually managed at the medium access control (MAC) layer. Despite the fact that the launch of 802.16 products has already been announced on the market by several manufacturers, the research literature still lacks a sufficient number of studies that specifically address the analysis of the 802.16 MAC protocol. In [4] the author performed a hybrid analytical-simulative analysis of the effect on the system performance of several MAC mechanisms, including the fragmentation of service data units (SDUs) and the padding of OFDM symbols. The performance with the time-division duplex (TDD) mode was partially analyzed in In this article, we review and analyze the mechanisms for supporting QoS at the IEEE 802.16 MAC layer. We then analyze by simulation the performance of IEEE 802.16 in two application scenarios, which consist of providing last-mile Internet access for residential and SME subscribers, respectively. Our analysis is aimed at showing the effectiveness of the 802.16 MAC protocol in providing differentiated services to applications with different QoS requirements, such as VoIP and Web. Abstract During the last few years, users all over the world have become more and more accustomed to the availability of broadband access. This has boosted the use of a wide variety both of established and recent multimedia applications. However, there are cases where it is too expensive for network providers to serve a community of users. This is typically the case in rural and suburban areas, where there is slow deployment (or no deployment at all) of traditional wired technologies for broadband access (e.g., cable modems, xDSL). In those cases, the most promising opportunity rests with Broadband Wireless Access technologies, such as the IEEE 802.16, also known as WiMAX. One of the features of the MAC layer of 802.16 is that it is designed to differentiate service among traffic categories with different multimedia requirements. This article focuses on mechanisms that are available in an 802.16 system to support quality of service (QoS) and whose effectiveness is evaluated through simulation. Quality of Servic

Semantic-based Context Modeling for Quality of Service Support in IoT Platforms

The Internet of Things (IoT) envisions billions of devices seamlessly connected to information systems, thus providing a sensing platform for applications. The availability of such a huge number of smart things will entail a multiplicity of devices collecting overlapping data and/or providing similar functionalities. In this scenario, efficient discovery and appropriate selection of things through proper context acquisition and management will represent a critical requirement and a challenge for future IoT platforms. In this work we present a practical approach to model and manage context, and how this information can be exploited to implement QoS-aware thing service selection. In particular, it is shown how context can be used to infer knowledge on the equivalence of thing services through semantic reasoning, and how such information can be exploited to allocate thing services to applications while meeting QoS requirements even in case of failures. The proposed approach is demonstrated through a simple yet illustrative experiment in a smart home scenario.European Commission's FP

Discriminating Quantum States in the Presence of a Deutschian CTC: A Simulation Analysis

In an article published in 2009, Brun et al. proved that in the presence of a “Deutschian” closed timelike curve, one can map $K$ distinct nonorthogonal states (hereafter, input set) to the standard orthonormal basis of a $K$-dimensional state space. To implement this result, the authors proposed a quantum circuit that includes, among SWAP gates, a fixed set of controlled operators (boxes) and an algorithm for determining the unitary transformations carried out by such boxes. To our knowledge, what is still missing to complete the picture is an analysis evaluating the performance of the aforementioned circuit from an engineering perspective. The objective of this article is, therefore, to address this gap through an in-depth simulation analysis, which exploits the approach proposed by Brun et al. in 2017. This approach relies on multiple copies of an input state, multiple iterations of the circuit until a fixed point is (almost) reached. The performance analysis led us to a number of findings. First, the number of iterations is significantly high even if the number of states to be discriminated against is small, such as 2 or 3. Second, we envision that such a number may be shortened as there is plenty of room to improve the unitary transformation acting in the aforementioned controlled boxes. Third, we also revealed a relationship between the number of iterations required to get close to the fixed point and the Chernoff limit of the input set used: the higher the Chernoff bound, the smaller the number of iterations. A comparison, although partial, with another quantum circuit discriminating the nonorthogonal states, proposed by Nareddula et al. in 2018, is carried out and differences are highlighted

From MANET to people-centric networking: Milestones and open research challenges

In this paper, we discuss the state of the art of (mobile) multi-hop ad hoc networking with the aim to present the current status of the research activities and identify the consolidated research areas, with limited research opportunities, and the hot and emerging research areas for which further research is required. We start by briefly discussing the MANET paradigm, and why the research on MANET protocols is now a cold research topic. Then we analyze the active research areas. Specifically, after discussing the wireless-network technologies, we analyze four successful ad hoc networking paradigms, mesh networks, opportunistic networks, vehicular networks, and sensor networks that emerged from the MANET world. We also present an emerging research direction in the multi-hop ad hoc networking field: people centric networking, triggered by the increasing penetration of the smartphones in everyday life, which is generating a people-centric revolution in computing and communications

End-to-End Bandwidth Reservation in IEEE 802.16 Mesh Networks

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