Platforms and Protocols for the Internet of Things

Building a general architecture for the Internet of Things (IoT) is a very complex task, exacerbated by the extremely large variety of devices, link layer technologies, and services that may be involved in such a system. In this paper, we identify the main blocks of a generic IoT architecture, describing their features and requirements, and analyze the most common approaches proposed in the literature for each block. In particular, we compare three of the most important communication technologies for IoT purposes, i.e., REST, MQTT, and AMQP, and we also analyze three IoT platforms: openHAB, Sentilo, and Parse. The analysis will prove the importance of adopting an integrated approach that jointly addresses several issues and is able to flexibly accommodate the requirements of the various elements of the system. We also discuss a use case which illustrates the design challenges and the choices to make when selecting which protocols and technologies to use

Robust Energy Management for Green and Survivable IP Networks

Despite the growing necessity to make Internet greener, it is worth pointing out that energy-aware strategies to minimize network energy consumption must not undermine the normal network operation. In particular, two very important issues that may limit the application of green networking techniques concern, respectively, network survivability, i.e. the network capability to react to device failures, and robustness to traffic variations. We propose novel modelling techniques to minimize the daily energy consumption of IP networks, while explicitly guaranteeing, in addition to typical QoS requirements, both network survivability and robustness to traffic variations. The impact of such limitations on final network consumption is exhaustively investigated. Daily traffic variations are modelled by dividing a single day into multiple time intervals (multi-period problem), and network consumption is reduced by putting to sleep idle line cards and chassis. To preserve network resiliency we consider two different protection schemes, i.e. dedicated and shared protection, according to which a backup path is assigned to each demand and a certain amount of spare capacity has to be available on each link. Robustness to traffic variations is provided by means of a specific modelling framework that allows to tune the conservatism degree of the solutions and to take into account load variations of different magnitude. Furthermore, we impose some inter-period constraints necessary to guarantee network stability and preserve the device lifetime. Both exact and heuristic methods are proposed. Experimentations carried out with realistic networks operated with flow-based routing protocols (i.e. MPLS) show that significant savings, up to 30%, can be achieved also when both survivability and robustness are fully guaranteed

BORDER: A Benchmarking Framework for Distributed MQTT Brokers

[EN] Message queuing telemetry transport (MQTT), one of the most popular application layer protocols for the Internet of Things, works according to a publish/subscribe paradigm where clients connect to a centralized broker. Sometimes (e.g., in high scalability and low-latency applications), it is required to depart from such a centralized approach and move to a distributed one, where multiple MQTT brokers cooperate together. Many MQTT brokers (both open source or commercially available) allow to create such a distributed environment: however, it is challenging to select the right solution due to the many available choices. This article proposes, therefore benchmarking framework for distributed MQTT brokers (BORDER), a framework for creating and evaluating distributed architectures of MQTT brokers with realistic and customizable network topologies. Based on isolated Docker containers and emulated network components, the framework provides quantitative metrics about the overall system performance, such as End-to-End latency as well as network and physical resources consumed. We use BORDER to compare five of the most popular MQTT brokers that allow the creation of distributed architectures and we release it as an open-source project to allow for reproducible researches.This work was supported in part by the Project BASE5G under Project 1155850 funded by Regione Lombardia within the framework POR FESR 2014-2020.Longo, E.; Redondi, A.; Cesana, M.; Manzoni, P. (2022). BORDER: A Benchmarking Framework for Distributed MQTT Brokers. IEEE Internet of Things. 9(18):17728-17740. https://doi.org/10.1109/JIOT.2022.3155872177281774091

Empirical assessment of VoIP overload detection tests

The control of communication networks critically relies on procedures capable of detecting unanticipated load changes. In this paper we explore such techniques, in a setting in which each connection consumes roughly the same amount of bandwidth (with VoIP as a leading example). We focus on large-deviations based techniques developed earlier in that monitor the number of connections present, and that issue an alarm when this number abruptly changes. The procedures proposed in are demonstrated by using real traces from an operational environment. Our experiments show that our detection procedure is capable of adequately identifying load changes

Smart transportation systems (STSs) in critical conditions

In the context of smart transportation systems (STSs) in smart cities, the use of applications that can help in case of critical conditions is a key point. Examples of critical conditions may be natural-disaster events such as earthquakes, hurricanes, floods, and manmade ones such as terrorist attacks and toxic waste spills. Disaster events are often combined with the destruction of the local telecommunication infrastructure, if any, and this implies real problems to the rescue operations.The quick deployment of a telecommunication infrastructure is essential for emergency and safety operations as well as the rapid network reconfigurability, the availability of open source software, the efficient interoperability, and the scalability of the technological solutions. The topic is very hot and many research groups are focusing on these issues. Consequently, the deployment of a smart network is fundamental. It is needed to support both applications that can tolerate delays and applications requiring dedicated resources for real-time services such as traffic alert messages, and public safety messages. The guarantee of quality of service (QoS) for such applications is a key requirement.In this chapter we will analyze the principal issues of the networking aspects and will propose a solution mainly based on software defined networking (SDN). We will evaluate the benefit of such paradigm in the mentioned context focusing on the incremental deployment of such solution in the existing metropolitan networks and we will design a "QoS App" able to manage the quality of service on top of the SDN controller

QoS-Based Middleware Architecture for Distributed Control Systems

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-85863-8_70This paper presents an implementation of a middleware architecture to control distributed systems. The main objective is providing a QoS level between the communications layer and the control layer. This architecture is based on the use of a hierarchical communications structure called logical namespace tree and a structured set of control processes interconnected, called logical sensors graph . This architecture is named Frame Sensor Adapter Control (FSA-Ctrl). In this architecture communication layer and control layer can manage the QoS policies. The communication layer is based on the Data Distribution Service (DDS), a standard proposed by Object Management Group (OMG). Control layer is derived from the Sensor Web Enablement (SWE) model proposed by Open Geospatial Consortium (OGC). Middleware components use messages queues to manage components QoS requirements. By means of QoS policies, control components can take important decisions about distributed questions, like components mobility or information redundancy detection.The architecture described in this article is a part of the coordinated project KERTROL: Kernel control on embedded system strongly connected. Education and Science Department, Spanish Government. CICYT: DPI2005-09327-C02-01/02.Poza-Lujan, J.; Posadas-Yagüe, J.; Simó Ten, JE. (2009). QoS-Based Middleware Architecture for Distributed Control Systems. En International Symposium on Distributed Computing and Artificial Intelligence 2008 (DCAI 2008). Springer. 587-595. https://doi.org/10.1007/978-3-540-85863-8_70S587595Matteucci, M.: Publish/Subscribe Middleware for Robotics: Requirements and State of the Art. Technical Report N 2003.3, Politecnico di Milano, Milano, Italy (2003)OMG. Data Distribution Service for Real-Time Systems, v1.1. Document formal/2005-12-04 (2005)Botts, M., Percivall, G., Reed, C., Davidson, J. (eds.): OGC. Sensor Web Enablement: Overview and High Level Architecture. OGC White Paper. OGC 06-050r2 (2006)Coulouris, G., Dollimore, J., Kindberg, T.: Distributed systems, concepts and design, 3rd edn. Addison-Wesley, Reading (2001)OMG. Real-Time Corba Specification version 1.1. Document formal /02-08-02 (2002)FIPA. Specfication. Part 2, Agent Communication Language. Foundation for Intelligent Physical Agents (1997)Hapner, M., Sharma, R., Fialli, J., Stout, K.: JMS specification, vol. 1.1. Sun Microsystems Inc., Santa Clara (2002)Pardo-Castellote, G.: OMG Data-Distribution Service: architectural overview. In: Proceedings of 23rd International Conference on Distributed Computing Systems Workshops, Providence, USA, vol. 19-22, pp. 200–206 (2003)Vogel, A., Kerherve, B., von Bochmann, G., Gecsei, J.: Distributed Multimedia and QoS: A Survey. IEEE Multimedia 2(2), 10–19 (1995)Crawley, E., Nair, R., Rajagopalan, B.: RFC 2386: A Framework for QoS-based Routing in the Internet. IETF Internet Draft, pp. 1–37 (1998)Botts, M., Percivall, G., Reed, C., Davidson, J.: OGC. Sensor Web Enablement: Overview and High Level Architecture. OpenGIS Consortium Inc. (2006)Posadas, J.L., Perez, P., Simo, J.E., Benet, G., Blanes, F.: Communication structure for sensory data in mobile robots. Engineering Applications of Artificial Intelligence 15(3-4), 341–350 (2002)Poza, J.L., Posadas, J.L., Simó, J.E., Benet, G.: Hierarchical communication system to manage maps in mobile robot navigation. In: Proceedings of International Conference on Automation, Control and Instrumentation, Valencia, Spain (2006)Poza, J.L., Posadas, J.L., Simó, J.E.: Distributed agent specification to an Intelligent Control Architecture. In: 6th International Workshop on Practical Applications of Agents and Multiagent Systems, Salamanca, Spain (in press, 2007

The Economics of Next Generation Access Networks and Regulatory Governance: Towards Geographic Patterns of Regulation

This paper examines the mix of technical, regulatory, and business strategy issues that arise in implementing next generation broadband platforms in Europe. Our review of some European studies on NGAN in Europe and our specific focus on the Italian situation, in particular on the competitive situation in Milano, shows the relevant flaw of continuing to advocate national patterns of regulation. In fact, the deployment of NGAN calls for a radical shift of regulation on a geographic level. The recognition that a NGAN business case does exist for OLO in a number of local areas, mainly metropolitan ones, has relevant regulatory implications.In the first place, since the conditions of competition differ significantly among local areas, regulation should promote both incumbents' and OLO's investments in NGAN by limiting ex ante interventions to those enduring economic bottlenecks found at a specific geographic markets level. In the second place, market definition is the most important step in the market analysis procedure to help decide whether to regulate a given service provided over a NGAN or not. We have proposed a taxonomy of local areas that may be adopted in a country like Italy for a correct geographic definition of markets 4 and 5 and, as a consequence, for the imposition of appropriate remedies.Next Generation Networks, geographic markets, geographic remedies, infrastructure sharing, market definition.

The Economics of Next Generation Access Networks and Regulatory Governance: Towards Geographic Patterns of Regulation

This paper examines the mix of technical, regulatory, and business strategy issues that arise in implementing next generation broadband platforms in Europe. Our review of some European studies on NGAN in Europe and our specific focus on the Italian situation, in particular on the competitive situation in Milano, shows the relevant flaw of continuing to advocate national patterns of regulation. In fact, the deployment of NGAN calls for a radical shift of regulation on a geographic level. The recognition that a NGAN business case does exist for OLO in a number of local areas, mainly metropolitan ones, has relevant regulatory implications.In the first place, since the conditions of competition differ significantly among local areas, regulation should promote both incumbents' and OLO's investments in NGAN by limiting ex ante interventions to those enduring economic bottlenecks found at a specific geographic markets level. In the second place, market definition is the most important step in the market analysis procedure to help decide whether to regulate a given service provided over a NGAN or not. We have proposed a taxonomy of local areas that may be adopted in a country like Italy for a correct geographic definition of markets 4 and 5 and, as a consequence, for the imposition of appropriate remedies.Next Generation Networks, geographic markets, geographic remedies, infrastructure sharing, market definition