Integration of heterogeneous devices and communication models via the cloud in the constrained internet of things

As the Internet of Things continues to expand in the coming years, the need for services that span multiple IoT application domains will continue to increase in order to realize the efficiency gains promised by the IoT. Today, however, service developers looking to add value on top of existing IoT systems are faced with very heterogeneous devices and systems. These systems implement a wide variety of network connectivity options, protocols (proprietary or standards-based), and communication methods all of which are unknown to a service developer that is new to the IoT. Even within one IoT standard, a device typically has multiple options for communicating with others. In order to alleviate service developers from these concerns, this paper presents a cloud-based platform for integrating heterogeneous constrained IoT devices and communication models into services. Our evaluation shows that the impact of our approach on the operation of constrained devices is minimal while providing a tangible benefit in service integration of low-resource IoT devices. A proof of concept demonstrates the latter by means of a control and management dashboard for constrained devices that was implemented on top of the presented platform. The results of our work enable service developers to more easily implement and deploy services that span a wide variety of IoT application domains

The Design and Implementation of OMA RESTful Location Services in Wireless Sensor Environments

Open Mobile Alliance (OMA) RESTful location services are standard RESTful Web services for terminal location. They are location technology-independent and enable applications’ portability and interoperability. Wireless sensors are electronic devices that can sense context: space, environment and physiology. Location is a key element of space context information. Wireless sensors can sense location with a level of accuracy that most other technologies cannot provide, which has made them the technology of choice for several applications. This thesis is about the design and implementation of OMA RESTful location services in wireless sensor environments for improved accuracy. A novel architecture is proposed. The architectural components and operational procedures are defined and implemented. The proof of concept prototype has been realized, along with the measurements for a preliminary performance evaluation. Several lessons were learned. For instance, it is possible to map location information for each of the OMA services to the sensor-based location information. However, using geographic coordinates (i.e. geographic latitude, longitude and altitude) to describe terminal location does not match with the fine-grained location accuracy provided by WSNs

Fine-grained management of CoAP interactions with constrained IoT devices

As open standards for the Internet of Things gain traction, the current Intranet of Things will evolve to a truly open Internet of Things, where constrained devices are first class citizens of the public Internet. However, the large amount of control over constrained networks offered by today's vertically integrated platforms, becomes even more important in an open IoT considering its promise of direct end-to-end interactions with constrained devices. In this paper a set of challenges is identified for controlling interactions with constrained networks that arise due to their constrained nature and their integration with the public Internet. Furthermore, a number of solutions are presented for overcoming these challenges by means of an intercepting intermediary at the edge of the constrained network

A holistic architecture using peer to peer (P2P) protocols for the internet of things and wireless sensor networks

Wireless Sensor Networks (WSNs) interact with the physical world using sensing and/or actuation. The wireless capability of WSN nodes allows them to be deployed close to the sensed phenomenon. Cheaper processing power and the use of micro IP stacks allow nodes to form an “Internet of Things” (IoT) integrating the physical world with the Internet in a distributed system of devices and applications. Applications using the sensor data may be located across the Internet from the sensor network, allowing Cloud services and Big Data approaches to store and analyse this data in a scalable manner, supported by new approaches in the area of fog and edge computing. Furthermore, the use of protocols such as the Constrained Application Protocol (CoAP) and data models such as IPSO Smart Objects have supported the adoption of IoT in a range of scenarios. IoT has the potential to become a realisation of Mark Weiser’s vision of ubiquitous computing where tiny networked computers become woven into everyday life. This presents the challenge of being able to scale the technology down to resource-constrained devices and to scale it up to billions of devices. This will require seamless interoperability and abstractions that can support applications on Cloud services and also on node devices with constrained computing and memory capabilities, limited development environments and requirements on energy consumption. This thesis proposes a holistic architecture using concepts from tuple-spaces and overlay Peer-to-Peer (P2P) networks. This architecture is termed as holistic, because it considers the flow of the data from sensors through to services. The key contributions of this work are: development of a set of architectural abstractions to provide application layer interoperability, a novel cache algorithm supporting leases, a tuple-space based data store for local and remote data and a Peer to Peer (P2P) protocol with an innovative use of a DHT in building an overlay network. All these elements are designed for implementation on a resource constrained node and to be extensible to server environments, which is shown in a prototype implementation. This provides the basis for a new P2P holistic approach that will allow Wireless Sensor Networks and IoT to operate in a self-organising ad hoc manner in order to deliver the promise of IoT

OMA LWM2M in a holistic architecture for the Internet of Things

Wireless Sensor Networks (WSNs) allow applications to interact with the physical world using nodes in an Internet of Things (IoT). Application level protocols such as the Constrained Application Protocol (CoAP) and data models such as IPSO Smart Objects and the Open Mobile Alliance Lightweight Specification (OMA LWM2M) have the potential to provide greater application interoperability and to ease the difficulties imposed by the heterogeneous nature, limited development environments and interfaces of existing solutions. This paper describes an architecture using a tuple-space based library for the flow of data from sensors to applications with defined service abstractions. It also compares the OMA LWM2M Information Model and the DMTF Common Information Model. It presents a `C' implementation of the OMA LWM2M model on our tuple-space running on the Contiki3.0 OS and considers the effectiveness of our architecture and its integration with existing CoAP and OMA LWM2M implementations

IoT-laitteiden emulaatio

Internet of Things (IoT) connects real life objects to the Internet. In this concept, devices, such as sensors and actuators, control the physical environment generating a large amount of data that can be used in applications and services. As they are typically constrained in memory and power, lightweight implementations are needed. Moreover, the number of Internet-connected devices is continually growing and thus, the technical solutions need to be scalable too. This introduces a problem; managing such a large amount of devices as well as testing the different IoT scenarios may be cumbersome with existing physical testbeds, which require a lot of configuring and lack scalability. This thesis proposes the design and implementation of emulated virtual devices using IoT specific protocols and data models, such as CoAP, LWM2M and IPSO objects. As device management is an important aspect of IoT, these devices are implemented to communicate with the management server through LWM2M interfaces in addition to communicating with each other. The emulated devices consist of virtual sensors and actuators represented as IPSO objects, which can be used to sense the simulated environment or control it with simple operations. Moreover, two use cases are defined and presented to create appropriate device logic. The virtualization of the devices is implemented by using Docker containers. They enable scaling to hundreds of devices, which is a key feature of the emulator. The design of the emualor follows CoAP and LWM2M specifications, which define the set of necessary functionalities and rules for the implementation. At the end of this thesis, the emulator is evaluated by comparing it to the initial design requirements along with scalability and bandwidth usage tests. Finally, future work for improving the emulator is presented.Internet-verkko on nopeasti laajentunut laitteisiin, jotka voivat mitata ja ohjata ympäristöään Internet-yhteyden välityksellä muodostaen Esineiden Internetin (eng. Internet of Things, IoT). Tällaisilla laitteilla, kuten sensoreilla, on yleensä rajallisesti muistia, tehoa ja kapasiteettia tiedonkäsittelyyn. Tästä syystä onkin tärkeää, että ne ovat tekniseltä toteutukseltaan mahdollisimman kevyitä. Lisäksi IoT-laitteiden määrä kasvaa jatkuvasti, mikä tarkoittaa sitä, että teknisten toteutusten on oltava myös skaalautuvia. Valtavan laitemäärän hallinta sekä erilaisten IoT-skenaarioiden testaaminen on kuitenkin hyvin vaivalloista fyysisessä testiympäristössä, erityisesti heikon skaalautuvuuden takia. Tämä diplomityö esittää ja toteuttaa ratkaisuksi emulaattorin, jolla voi emuloida useita virtuaalisia laitteita käyttäen IoT-protokollia ja datamalleja, kuten CoAP- ja LWM2M-protokollia sekä IPSO-objekteja. Koska laitehallinta on olennainen osa IoT-konseptia, virtuaaliset laitteet on toteutettu niin, että ne voivat paitsi kommunikoida keskenään, niitä voi myös hallita hallintapalvelimen kautta LWM2M-operaatioita käyttäen. Laitteet koostuvat virtuaalisista sensoreista ja kytkimistä, joita mallinnetaan IPSO-objekteilla. Niiden avulla dataa voidaan kerätä ja lähettää simuloidussa ympäristössä. Lisäksi, työssä esitellään kaksi testitapausta, joihin toteutettu laitelogiikka pohjautuu. Virtualisointi tapahtuu Docker-platformin avulla, joka mahdollistaa skaalaamisen satoihin laitteisiin. Emulaattorin toteutus pohjautuu CoAP- ja LWM2M-standardeihin, jotka määrittävät sallitut toiminnallisuudet ja operaatiot. Diplomityön lopussa emulaattori arvioidaan toteutuneiden suunnitteluvaatimusten sekä tehtyjen skaalautuvuustestien ja taajuuskaistan käyttöä tarkastelevien testien perusteella

CoAP Infrastructure for IoT

The Internet of Things (IoT) can be seen as a large-scale network of billions of smart devices. Often IoT devices exchange data in small but numerous messages, which requires IoT services to be more scalable and reliable than ever. Traditional protocols that are known in the Web world does not fit well in the constrained environment that these devices operate in. Therefore many lightweight protocols specialized for the IoT have been studied, among which the Constrained Application Protocol (CoAP) stands out for its well-known REST paradigm and easy integration with existing Web. On the other hand, new paradigms such as Fog Computing emerges, attempting to avoid the centralized bottleneck in IoT services by moving computations to the edge of the network. Since a node of the Fog essentially belongs to relatively constrained environment, CoAP fits in well. Among the many attempts of building scalable and reliable systems, Erlang as a typical concurrency-oriented programming (COP) language has been battle tested in the telecom industry, which has similar requirements as the IoT. In order to explore the possibility of applying Erlang and COP in general to the IoT, this thesis presents an Erlang based CoAP server/client prototype ecoap with a flexible concurrency model that can scale up to an unconstrained environment like the Cloud and scale down to a constrained environment like an embedded platform. The flexibility of the presented server renders the same architecture applicable from Fog to Cloud. To evaluate its performance, the proposed server is compared with the mainstream CoAP implementation on an Amazon Web Service (AWS) Cloud instance and a Raspberry Pi 3, representing the unconstrained and constrained environment respectively. The ecoap server achieves comparable throughput, lower latency, and in general scales better than the other implementation in the Cloud and on the Raspberry Pi. The thesis yields positive results and demonstrates the value of the philosophy of Erlang in the IoT space