Heterogeneous sensor database framework for the sensor observation service: integrating remote and in-situ sensor observations at the database backend

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.Environmental monitoring and management systems in most cases deal with models and spatial analytics that involve the integration of in-situ and remote sensor observations. In-situ sensor observations and those gathered by remote sensors are usually provided by different databases and services in real-time dynamic service systems like the Geo-Web Services. Thus, data have to be pulled from different databases and transferred over the web before they are fused and processed on the service middleware. This process is very massive and unnecessary communication and work load on the service, especially when retrieving massive raster coverage data. Thus in this research, we propose a database model for heterogeneous sensortypes that enables geo-scientific processing and spatial analytics involving remote and in-situ sensor observations at the database level of the Sensor Observation Service, SOS. This approach would be used to reduce communication and massive workload on the Geospatial Web Service, as well make query request from the user end a lot more flexible. Hence the challenging task is to develop a heterogeneous sensor database model that enables geoprocessing and spatial analytics at the database level and how this could be integrated with the geo-web services to reduce communication and workload on the service and as well make query request from the client end more flexible through the use of SQL statements

Performance analysis of topologies for Web-based Real-Time Communication (WebRTC)

Real-time Communications over the Web (WebRTC) is being developed to be the next big improvement for rich web applications. This enabler allow developers to implement real-time data transfer between browsers by using high level Application Programing Interfaces (APIs). Running real-time applications in browsers may lead to a totally new scenario regarding usability and performance. Congestion control mechanisms may influence the way this data is sent and metrics such as delay, bit rate and loss are now crucial for browsers. Some mechanisms that have been used in other technologies are implemented in those browsers to handle the internals of WebRTC adding complexity to the system but hiding it from the application developer. This new scenario requires a deep study regarding the ability of browsers to adapt to those requirements and to fulfill all the features that are enabled. We investigate how WebRTC performs in a real environment running over an current web application. The capacity of the internal mechanisms to adapt to the variable conditions of the path, consumption resources and rate. Taking those principles, we test a range of topologies and use cases that can be implemented with the current version of WebRTC. Considering this scenario we divide the metrics in two categories, host and network indicators. We compare the results of those tests with the expected output based on the defined protocol in order to evaluate the ability to perform real-time media communication over the browser

Notes on the Music: A social data infrastructure for music annotation

Beside transmitting musical meaning from composer to reader, symbolic music notation affords the dynamic addition of layers of information by annotation. This allows music scores to serve as rudimentary communication frameworks. Music encodings bring these affordances into the digital realm; though annotations may be represented as digital pen-strokes upon a score image, they must be captured using machine-interpretable semantics to fully benefit from this transformation. This is challenging, as annota- tors’ requirements are heterogeneous, varying both across different types of user (e.g., musician, scholar) and within these groups, de- pending on the specific use-case. A hypothetical all-encompassing tool catering to every conceivable annotation type, even if it were possible to build, would vastly complicate user interaction. This additional complexity would significantly increase cognitive load and impair usability, particularly in dynamic real-time usage con- texts, e.g., live annotation during music rehearsal or performance. To address this challenge, we present a social data infrastructure that facilitates the creation of use-case specific annotation toolkits. Its components include a selectable-score module that supports customisable click-and-drag selection of score elements (e.g., notes, measures, directives); the Web Annotations data model, extended to support the creation of custom, Web-addressable annotation types supporting the specification and (re-)use of annotation palettes; and the Music Encoding and Linked Data (MELD) Javascript client library, used to build interfaces that map annotation types to render- ing and interaction handlers. We have extended MELD to support the Solid platform for social Linked Data, allowing annotations to be privately stored in user-controlled Personal Online Datastores (Pods), or selectively shared or published. To demonstrate the feasi- bility of our proposed approach, we present annotation interfaces employing the outlined infrastructure in three distinct use-cases: scholarly communication; music rehearsal; and rating during music listening

Designing and prototyping WebRTC and IMS integration using open source tools

WebRTC, or Web Real-time Communications, is a collection of web standards that detail the mechanisms, architectures and protocols that work together to deliver real-time multimedia services to the web browser. It represents a significant shift from the historical approach of using browser plugins, which over time, have proven cumbersome and problematic. Furthermore, it adopts various Internet standards in areas such as identity management, peer-to-peer connectivity, data exchange and media encoding, to provide a system that is truly open and interoperable. Given that WebRTC enables the delivery of multimedia content to any Internet Protocol (IP)-enabled device capable of hosting a web browser, this technology could potentially be used and deployed over millions of smartphones, tablets and personal computers worldwide. This service and device convergence remains an important goal of telecommunication network operators who seek to enable it through a converged network that is based on the IP Multimedia Subsystem (IMS). IMS is an IP-based subsystem that sits at the core of a modern telecommunication network and acts as the main routing substrate for media services and applications such as those that WebRTC realises. The combination of WebRTC and IMS represents an attractive coupling, and as such, a protracted investigation could help to answer important questions around the technical challenges that are involved in their integration, and the merits of various design alternatives that present themselves. This thesis is the result of such an investigation and culminates in the presentation of a detailed architectural model that is validated with a prototypical implementation in an open source testbed. The model is built on six requirements which emerge from an analysis of the literature, including previous interventions in IMS networks and a key technical report on design alternatives. Furthermore, this thesis argues that the client architecture requires support for web-oriented signalling, identity and call handling techniques leading to a potential for IMS networks to natively support these techniques as operator networks continue to grow and develop. The proposed model advocates the use of SIP over WebSockets for signalling and DTLS-SRTP for media to enable one-to-one communication and can be extended through additional functions resulting in a modular architecture. The model was implemented using open source tools which were assembled to create an experimental network testbed, and tests were conducted demonstrating successful cross domain communications under various conditions. The thesis has a strong focus on enabling ordinary software developers to assemble a prototypical network such as the one that was assembled and aims to enable experimentation in application use cases for integrated environments

Reaaliaikainen kaksisuuntainen tiedonsiirto digitaalisen kaksosen kanssa verkkorajapinnan kautta

Technological advancements in industry have paved way for the fourth industrial revolution called Industry 4.0. One critical aspect of this revolution is the usage of digital twins in product design, production, and service. A common depiction of a digital twin consists of three parts: a physical twin, its digital twin, and the data exchanged between them. In industry, one common solution for the data exchange between the digital twin and its physical twin is OPC Unified Architecture (OPC UA) communication protocol. The protocol provides a solution to collect data from devices along an entire production line. Communication with OPC UA servers requires carefully studying the protocol specification, which can deter new developers from creating applications with the data collected by the servers. The goal of this thesis is to develop a web-based application program interface (API) that simplifies transferring data with an OPC UA server. The API is intended to be made with a popular technology that is already widely known among developers. It would lower the learning curve for utilizing the data on OPC UA servers. Thus, more developers can be tempted to start developing applications with the data. As the API is web-based, it is accessible by any web capable device bringing the data available to virtually any programming language and platform. Requirements for the API beyond the functionalities concern its efficiency and capability of handling real-time data exchange situations. To test the API’s performance, a case study is made: a web-based control application. The control application uses the API in real-time to both write control signals to and read sensor values from the OPC UA server. The API performance is evaluated by measuring its request completion time in both controlled environment and real use cases. The developed API was considered to be fast enough for user-based input and even applications that required fast synchronisation of values from different data sources. However, the API did add considerable latency compared using the OPC UA server directly which might be a problem in some applications that require extremely time sensitive data from the data server.Teknologian kehitys teollisuudessa on mahdollistanut neljännen teollisuuden vallankumouksen, jota kutsutaan myös nimellä Industry 4.0. Yksi tämän vallankumouksen tärkeitä puolia on digitaalisten kaksosten hyödyntäminen tuotesuunnittelussa, tuotannossa, sekä huoltamisessa. Yleensä digitaalisen kaksosen käsitteen sanotaan koostuvan kolmesta osasta: fyysisestä kaksosesta, sen digitaalisesta kaksosesta ja niiden välisestä tiedonsiirrosta. Teollisuudessa eräs yleinen tapa toteuttaa tiedonsiirto fyysisen ja digitaalisen kaksosen välillä on OPC Unified Architecture (OPC UA) -kommunikaatioprotokollalla. Protokolla tarjoaa ratkaisun datan keruuseen koko tuotantolinjan prosesseista. Kommunikointi OPC UA -palvelimen kanssa vaatii protokollan määrittelyyn syventymistä, mikä saattaa lannistaa uusia kehittäjiä, jotka voisivat luoda sovelluksia palvelimen keräämälle datalle. Työn tavoitteena on kehittää web-pohjainen ohjelmointirajapinta, joka yksinkertaistaa sovellusten kehittämistä OPC UA -palvelimen kanssa. Ohjelmointirajapinta on tarkoitus kehittää ohjelmistokehittäjille tunnetulla teknologialla. Web-rajapinnalla voi laskea oppimiskynnystä OPC UA -palvelimen datan hyödyntämiseen. Tällöin uudet kehittäjät saattavat olla kiinnostuneempia kehittämään käyttökohteita datalle. Web-rajapinnalla on mahdollista tarjota data mille tahansa alustalle tai ohjelmointikielelle, jolla on webominaisuudet. Toiminnallisuuksien lisäksi rajapinnan vaatimukset kohdistuvat sen tehokkuuteen ja kykyyn käsitellä reaaliaikaista tiedonsiirtoa. Rajapinnan testausta varten tehdään tapaustutkimus: Web-pohjainen ohjaussovellus. Ohjaussovellus käyttää rajapintaa reaaliajassa kirjoittamaan ohjaussignaaleja, sekä lukemaan anturiarvoja OPC UA -palvelimelta. Rajapinnan suorituskykyä arvioidaan mittaamalla sen pyyntöjen suoritusaikoja sekä hallitussa ympäristössä, että tosikäyttötilanteissa. Kehitetty ohjelmointirajapinta todetaan testeissä tarpeeksi nopeaksi käyttäjäsyötteelle, sekä ohjelmille, jotka tarvitsevat nopeaa synkronointia arvoille eri tietolähteistä. Rajapinta kuitenkin lisäsi merkittävän viiveen verratessa sitä OPC UA -palvelimen suoraan käyttöön. Tämä saattaa aiheuttaa ongelmia joissain käyttötilanteissa, jotka tarvitsevat tarkkaa aikariippuvaista dataa palvelimelta

Reflections on security options for the real-time transport protocol framework

The Real-time Transport Protocol (RTP) supports a range of video conferencing, telephony, and streaming video ap- plications, but offers few native security features. We discuss the problem of securing RTP, considering the range of applications. We outline why this makes RTP a difficult protocol to secure, and describe the approach we have recently proposed in the IETF to provide security for RTP applications. This approach treats RTP as a framework with a set of extensible security building blocks, and prescribes mandatory-to-implement security at the level of different application classes, rather than at the level of the media transport protocol

From Sensor to Observation Web with Environmental Enablers in the Future Internet

This paper outlines the grand challenges in global sustainability research and the objectives of the FP7 Future Internet PPP program within the Digital Agenda for Europe. Large user communities are generating significant amounts of valuable environmental observations at local and regional scales using the devices and services of the Future Internet. These communities’ environmental observations represent a wealth of information which is currently hardly used or used only in isolation and therefore in need of integration with other information sources. Indeed, this very integration will lead to a paradigm shift from a mere Sensor Web to an Observation Web with semantically enriched content emanating from sensors, environmental simulations and citizens. The paper also describes the research challenges to realize the Observation Web and the associated environmental enablers for the Future Internet. Such an environmental enabler could for instance be an electronic sensing device, a web-service application, or even a social networking group affording or facilitating the capability of the Future Internet applications to consume, produce, and use environmental observations in cross-domain applications. The term ?envirofied? Future Internet is coined to describe this overall target that forms a cornerstone of work in the Environmental Usage Area within the Future Internet PPP program. Relevant trends described in the paper are the usage of ubiquitous sensors (anywhere), the provision and generation of information by citizens, and the convergence of real and virtual realities to convey understanding of environmental observations. The paper addresses the technical challenges in the Environmental Usage Area and the need for designing multi-style service oriented architecture. Key topics are the mapping of requirements to capabilities, providing scalability and robustness with implementing context aware information retrieval. Another essential research topic is handling data fusion and model based computation, and the related propagation of information uncertainty. Approaches to security, standardization and harmonization, all essential for sustainable solutions, are summarized from the perspective of the Environmental Usage Area. The paper concludes with an overview of emerging, high impact applications in the environmental areas concerning land ecosystems (biodiversity), air quality (atmospheric conditions) and water ecosystems (marine asset management)

IETF standardization in the field of the Internet of Things (IoT): a survey

Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities

Building real-time embedded applications on QduinoMC: a web-connected 3D printer case study

Single Board Computers (SBCs) are now emerging with multiple cores, ADCs, GPIOs, PWM channels, integrated graphics, and several serial bus interfaces. The low power consumption, small form factor and I/O interface capabilities of SBCs with sensors and actuators makes them ideal in embedded and real-time applications. However, most SBCs run non-realtime operating systems based on Linux and Windows, and do not provide a user-friendly API for application development. This paper presents QduinoMC, a multicore extension to the popular Arduino programming environment, which runs on the Quest real-time operating system. QduinoMC is an extension of our earlier single-core, real-time, multithreaded Qduino API. We show the utility of QduinoMC by applying it to a specific application: a web-connected 3D printer. This differs from existing 3D printers, which run relatively simple firmware and lack operating system support to spool multiple jobs, or interoperate with other devices (e.g., in a print farm). We show how QduinoMC empowers devices with the capabilities to run new services without impacting their timing guarantees. While it is possible to modify existing operating systems to provide suitable timing guarantees, the effort to do so is cumbersome and does not provide the ease of programming afforded by QduinoMC.http://www.cs.bu.edu/fac/richwest/papers/rtas_2017.pdfAccepted manuscrip