Open Connectivity Foundation Research Articles

Optimal Environment Control Mechanism Based on OCF Connectivity for Efficient Energy Consumption in Greenhouse

Greenhouses are a productive system that allows us to respond to the growing global demand for fresh and healthy food throughout the year, but the greenhouse environment is not easily controlled because its climate parameters are interrelated. However, the numbers of the actuator are operated parallelly to maintain the greenhouse environment; as a result, the energy consumption of greenhouses is high. In this study, we presented the optimization module by considering the outdoor environment with the aim of minimum energy consumption. Metaheuristic-based differential evaluation (DE) is used to optimize the climate parameters by considering indoor and outdoor environmental constraints. Furthermore, the long short-term memory (LSTM)-based inference model is offloaded on the Internet of Things (IoT) device to predict the next environmental situation. The objective function selects the optimal parameters within user preferences with minimum energy consumption based on the inferred parameter value. The open-source software framework IoTivity, implementing open connectivity foundation (OCF) technical standards, is used for the real-time connection between IoT devices and the IoT platform. Greenhouse owners can set the preferences based on the requirements of plants in the greenhouse by using a smart and remotely accessible Android-based interface. A fuzzy logic-based control module operates on an IoT device that maps the optimized parameters with the actuator and operates accordingly. The proposed model is analyzed, and the performance is evaluated in terms of energy consumption for each climate parameter and actuator in the greenhouse. The results show that the proposed mechanism saves 36% of energy.

An OCF-IoTivity enabled smart-home optimal indoor environment control system for energy and comfort optimization

The growing energy demand with diminishing energy resources calls for development of optimal indoor control system through accurate energy and occupant comfort modeling in a smart-home. While some major obstacles faced by smart-home IoT network are heterogeneity and disparate IP frameworks resulting in a connectivity and interoperability issues. In this paper we developed a new Open Connectivity Foundation (OCF) based prediction assisted optimal control framework for optimizing energy consumption and maximizing occupant comfort in smart-home. To the best of our knowledge, we are the first to design a scalable, secure, and inter-operable optimal control solution for smart-home IoT networks. The developed framework offloads machine learning models on IoT device for accurate energy and thermal comfort modeling to enable prediction assisted optimization. The system enables edge analytics using deep learning based inference models for proactive response. For optimization standard Firefly algorithm is modified based on inertia weight approach to achieve improved performance. OCF based optimal actuator control test-bed deployment and real-time experimentation is conducted to evaluate the performance of the system. Empirical investigation verified the effectiveness of proposed framework with energy saving scope of 36.82%, 5 s average response time and 3.36 MS Round Trip Time.

Intelligent digital twin for federated learning in AIoT networks

Federated Learning (FL) promises to solve the data privacy problem by training the local model on each node and sharing the model parameters instead of the data itself. Next, the FL server applies model aggregation techniques to aggregate the received models and broadcast the resulting model to the connected clients. This study proposes a Digital Twin-based Federated Learning (DT-FL) framework to virtually monitor and controls the remotely deployed physical clients and their training process. The connection-oriented protocol, Open Connectivity Foundation (OCF) Iotivity, connects the FL clients with the FL server to ensure packet delivery. OCF Iotivity sends/receives the models’ weights to/from the server, and Hyper Text Transfer Protocol (HTTP) is used to monitor clients’ local training. After receiving partially trained models from clients, the server performs the optimal model selection using the normal distribution method by considering the performance of the model. Finally, the best-selected models are aggregated, and the final model is broadcasted to the clients. The framework utilizes Raspberrypi 4 devices as clients with limited computational capabilities, due to which the experiments are conducted with structured energy consumption data. The dataset comprises of 8 multistory residential buildings located in different geographical locations of the Republic of Korea. Each residential building is treated as an FL client and registered on DT using the IP address and port number. The DT-FL framework can be used with classification and regression datasets, and the model architecture for that data can be designed on the DT platform. The experiments are conducted with the partial and full participation of clients. The results show the minimum delay time in physical and virtual object synchronization and better performance and generalization of the global model for each client. The source code of the proposed DT-FL framework is available on GitHub.

Enhanced Interoperating Mechanism Between OneM2M and OCF Platform Based on Rules Engine and Interworking Proxy in Heterogeneous IoT Networks

In recent years, the Internet of Things (IoT) is growing rapidly and is being applied in a variety of industries including healthcare, smart homes, and smart cities. Many standard IoT platforms are proposed to connect and communicate with IoT devices easily and securely such as oneM2M, GoogleWeave and Apple HomeKit. However, this makes IoT application development difficult as it requires IoT devices and applications to support multiple protocols to connect different IoT platforms. Therefore, it is necessary to provide a consistent schema to support interoperability in heterogeneous IoT networks. In this paper, we propose how to design and implement interoperating schema between two edge servers oneM2M and Open Connectivity Foundation (OCF) with heterogeneous IoT devices. Specifically, we build proxies for bridging oneM2M Mobius edge server and OCF IoTivity edge server. The sensor data is collected from various IoT devices and sent to an edge server with a compatible platform. Next, the data stored in each server will be exchanged with the other server through a proposed interworking proxy. We also use a rules engine to automatically identify registered devices to support edge server interaction within the same domain and across domains. In addition, we build a web application in each edge server to provide friendly IoT services (data visualization) to clients from different environments. In order to evaluate our system, we collect the delay time of each process in the edge servers. The results show that our proposal is completely applicable in practice.

Internet of Things (IoT) Device Management in Rural Areas to Support Precision Agriculture

Internet of Things (IoT) devices have an important role in supporting precision agriculture systems, namely acting as the first layer consisting of several nodes in a limited network group as a producer of land, environmental and plant parameter data that will be processed at the next level. This node is an embedded system consisting of sensors, microcontrollers, power supplies and wireless communication media. The challenge that arises is when the number of new nodes that will be connected to the concentrator in a limited network group is quite large and is still done manually by the user, so that it has the potential to cause complexity and errors in configuration. The purpose of this research is to design a self-registration scheme from each new node to the concentrator in a restricted network group automatically. The method used by new nodes for self-registration is to read the RSSI (Received Signal Strength Indicator) value from the concentrator, then exchange metadata according to the OCF (Open Connectivity Foundation) standard. The concentrator will refer to the maximum number of nodes allowed to join the group and check the metadata of the new node. If the registration process is successful, the new node will gain access rights to communicate with the concentrator and its closest neighbours in the network group. This mechanism will help farmers in rural areas to be able to configure Internet of Things (IoT) devices easily and provide benefits in supporting precision agriculture.

OCF-to-ZigBee (O2Z) Bridging Technique and IoTivity-Based Implementation

As the number of Internet-of-Things (IoT) devices explosively increases, developing the IoT standard is essential to control those devices efficiently. To do this, many vendors and IT companies have established IoT standard organizations. In particular, the Open Connectivity Foundation (OCF), the most influential IoT standard organization, has been actively developing the OCF standard and an open-source software framework called IoTivity. The OCF standard supports interoperability through bridging techniques toward non-OCF devices of other ecosystems, such as ZigBee, Bluetooth low energy, oneM2M, and AllJoyn. Among several bridging techniques, we focus on developing an OCF-to-ZigBee (O2Z) bridging technique which is very important to provide the scalability of the OCF standard. This is because there are many ZigBee devices to construct IoT applications (e.g., lightening, heating, and sensing), and the number of them is steadily increasing. In this article, we introduce the O2Z bridging technique adopted in the OCF standard, and describe how to implement an O2Z bridging plugin as a software component of IoTivity. This work would provide a good guideline for developing other bridging techniques toward other IoT ecosystems.

A Blockchain-Based OCF Firmware Update for IoT Devices

As the usage growth rate of Internet of Things (IoT) devices is increasing, various issues related to these devices need attention. One of them is the distribution of the IoT firmware update. The IoT devices’ software development does not end when the manufacturer sells the devices to the market. It still needs to be kept updated to prevent cyber-attacks. The commonly used firmware update process, over-the-air (OTA), mostly happens in a centralized way, in which the IoT devices directly download the firmware update from the manufacturer’s server. This central architecture makes the manufacturer’s server vulnerable to single-point-of-failure and latency issues that can delay critical patches from being applied to vulnerable devices. The Open Connectivity Foundation (OCF) is one organization contributing to providing interoperability services for IoT devices. In one of their subject areas, they provide a firmware update protocol for IoT devices. However, their firmware update process does not ensure the integrity and security of the patches. In this paper, we propose a blockchain-based OCF firmware update for IoT devices. Specifically, we introduce two types of firmware update protocol, direct and peer-to-peer updates, integrated into OCF firmware update specifications. In the direct scenario, the device, through the IoT gateway, can download the new firmware update from the manufacturer’s server. Meanwhile, in the peer-to-peer scheme, the device can query the update from the nearby gateways. We implemented our protocol using Raspberry Pi hardware and Ethereum-based blockchain with the smart contracts to record metadata of the manufacturer’s firmware updates. We evaluated the proposed system’s performance by measuring the average throughput, the latency, and the firmware update distribution’s duration. The analysis results indicate that our proposal can deliver firmware updates in a reasonable duration, with the peer-to-peer version having a faster completion time than the direct one.

Development of Cloud of Things Based on Proxy Using OCF IoTivity and MQTT for P2P Internetworking

In recent years, the development of Cloud and Internet of Things (IoT) integrated applications are becoming more and more popular among developers, and this combined system is described as Cloud of Things (CoT). Cloud of Things can be utilized for finding optimal solutions for various problems. CoT is one of the essential methods for the construction and development of smart cities. With the installation of CoT based technologies, people can be able to check, control environmental parameters through intelligent embedded devices. In this paper, we present a CoTarchitecture based on proxy using Peer to Peer (P2P) connectivity for interworking IoT devices and Cloud. Proposed Cloud of Things architecture supports IoT devices’ contextual data transformation to the Cloud-based on P2P connectivity using Open Connectivity Foundation (OCF) IoTivity and Message Queuing Telemetry Transport (MQTT) protocol. The proposed system provides a collection of huge sensing information via Internet of Things devices and upload gathered data to Cloud for further analyzation. The proxy can acquire sensor data from the Internet of Things networks and then publish the data as messages to the subject in Internet of Things global Cloud. Moreover, this Cloud of Things architecture supports the peer to peer internetworking for communication of client devices and embedded devices. Finally, we also compared the IoT service of global Cloud platforms in CoT experiments.

A Novel Approach towards Resource Auto-Registration and Discovery of Embedded Systems Based on DNS

The Internet of Things (IoT) is expected to deliver a whole range of new services to all parts of our society, and improve the way we work and live. The challenges within the Internet of Things are often related to interoperability, device resource constraints, a device to device connection and security. One of the essential elements of identification for each Internet of Things devices is the naming system and addresses. With this naming system, Internet of Things devices can be able to be discoverable by users. In this paper, we propose the IoT resource auto-registration and accessing indoor services based on Domain Name System (DNS) in the Open Connectivity Foundation (OCF) environment. We have used the Internet of Things Platform and DNS server for IoT Resource auto-registration and discovery in the Internet Protocol version 4 (IPv4). An existing system called Domain Name Auto-Registration in Internet Protocol version 6 can be used for Internet of Things devices for auto-registration and resource discovery. However, this system is not acceptable in the existing internet networks, because the highest percentage of the networks on the Internet are configured in Internet Protocol version 4. Through the proposed auto-registration system, clients can be able to discover the resources and access the services in the OCF network. Constrained Application Protocol (CoAP) is utilized for the IoT device auto-registration and accessing the services in the OCF network.

Resource Management Based on OCF for Device Self-Registration and Status Detection in IoT Networks

Recently, there are heterogeneous devices that connect to the Internet to provide ubiquitous and intelligent services based on sensors and actuators in the network of the Internet of Things (IoT). The resources of IoT represent the physical entities on the Internet to expose functions through services. Resource management is necessary to enable a massive amount of IoT-connected devices to be discoverable and accessible in the network of IoT. In this paper, we propose an IoT resource management to provide schemes of device self-registration and status detection for devices based on the Open Connectivity Foundation (OCF) standard. This device self-registration scheme is based on an agent that is proposed for registering devices itself which deployed in the OCF network. The devices host the OCF resources to provide IoT services such as sensing and controlling through the sensors and actuators. For a group of devices, an agent-based self-registration is proposed to register the resources. Through the proposed self-registration, the information of IoT devices is published using profile and saved in the management platform that enables the clients to discover the resources and access the services. For accessing the IoT resources in the OCF network, an interworking proxy is proposed to support the communications between web clients and devices over Hypertext Transfer Protocol (HTTP) and Constrained Application Protocol (CoAP) based on OCF. Furthermore, through the interoperability of the resources using the registered information, a real-time monitoring scheme is proposed based on periodic request and response for the status detection of deployed devices.

Towards interoperability between OPC UA and OCF

Abstract The paper deals with the interoperability issue inside Industry 4.0. This last features the application in industrial contexts of modern Information & Communication Technology (ICT) concepts, such as Internet of Things (IoT). Current literature presents several proposals aimed to improve interoperability between reference communication standards of Industry 4.0 and IoT ecosystems. Among them, several research activities deal with interoperability between OPC UA international standard (IEC 62541) and IoT. The paper proposes a novel solution towards interoperability between OPC UA and IoT, focusing on the integration of OPC UA with the emerging specifications for the IoT defined by Open Connectivity Foundation (OCF). The proposal is original as interoperability issues between OPC UA and OCF are not treated at the moment. The proposal may also have a potential impact on the current definition of OCF specifications, as it may contribute to the current definition of an OCF Bridge Device which at the moment does not allow interoperability between OCF and OPC UA.

Multiple Protocols Interworking With Open Connectivity Foundation in Fog Networks

Intelligent applications have greatly promoted the development of fog computing. The protocols have emerged diversely, causing the problems in the interworking between terminal devices, which has seriously hindered the development of fog computing. Based on the open connectivity foundation (OCF) protocol, this paper proposes an interworking solution for intelligent devices and designs an OCF-based multi-protocol gateway to access non-OCF services. The main functions are divided into three categories: manager, adapter, and device agent. In part, the manager provides centralized management services, the adapter provides communication services between the client and the server device, and the device agent provides access services for the server device. The semantic conversion scheme of an OCF protocol with other protocols is proposed in the device agent, which solves the problem of interoperability between an OCF client device and non-OCF server devices. Finally, the OCF multi-protocol interworking gateway was built, and the semantic conversion between the OCF protocol, AllJoyn protocol, and the ZigBee protocol was implemented. The interoperability between the OCF client, AllJoyn device, and ZigBee device was verified.

Improved Resource Directory Based on DNS Name Self-Registration for Device Transparent Access in Heterogeneous IoT Networks

With the rapid development of Internet of Things (IoT) technologies in various domains including smart homes, smart cities, smart factories and smart buildings where Internet-connected devices are deployed to provide IoT services based on heterogeneous frameworks and platforms. Many standard protocols, frameworks, libraries and specifications have been proposed for developing IoT applications. Therefore, providing a consistent scheme is important for supporting the interoperability in heterogeneous IoT devices to interact in the same domain and cross-domain. Moreover, supporting the device transparent access for clients to consume IoT service from the different environment that can provide user-friendly service scenarios although the user consumes services in different IoT networks. In this paper, we propose an improved Resource Directory (RD) based on a Domain Name System (DNS) Name Self-Registration (DNSNSR) for the device transparent access in heterogeneous IoT networks. For supporting proposed DNSNSR, an IoT RD is presented based on the Open Connectivity Foundation (OCF) standard specification to provide device registration and discovery service. Through the registration interface, the IoT RD configures the DNS names using Bind 9 to provide the DNS service in an IoT network based on the published device information. Using the discovery interface of RD and name resolution of DNS, the IoT Client gets devices information including (Identifier) ID and Internet Protocol (IP) to access IoT Devices without considering underlying protocols through the interworking proxy of proposed RD in heterogeneous IoT networks. Therefore, the proposed RD based on DNSNSR enables the IoT devices to be discovered by IoT clients in the various environment through the RD and DNS functions. Furthermore, using the OCF-direct and proxy-based access mechanism, the proposed RD based on DNSNSR supports IoT devices to be accessed by clients in various IoT environment.

Consistent Registration and Discovery Scheme for Devices and Web Service Providers Based on RAML Using Embedded RD in OCF IoT Network

The Internet of Things (IoT) is comprised of connected devices which are equipped with sensors, actuators, and applications to provide services for enabling those objects to connect and exchange data. For these connected devices and the IoT network environment, heterogeneous protocols and frameworks have been published and applied to provide novel IoT services in our daily life. On the Internet, most of the services are provided by existing web service providers which are based on the high-performance processor, storage, and stable power supply. However, devices of the IoT are developed for constrained environments using the small size of equipment to provide seamless services ubiquitously. For accessing the constrained devices and existing web service providers using the clients in the IoT networks such as smart homes, the services of servers from the devices and web service providers shall be discovered by the clients using a consistent discovery service. In this paper, a consistent registration and discovery scheme is proposed for the devices and web service providers in the Open Connectivity Foundation (OCF)-based IoT network. For supporting the proposed scheme, an embedded resource directory (RD) server is proposed to provide a consistent registration service that is used for publishing information of devices and web service providers. For the registration, a unified profile format is used that is based on the RESTful API Modeling Language to describes the information of devices and web service providers. Furthermore, the discovery service provides the consistent interface to discover the registered devices and web service providers by the client using the unified user interface. Accordingly, the client can access the resources of devices and web service providers based on the discovered information.

Bridging for cross protocol talk in IOT devices using windows communication foundation

In the Internet of Things (IoT), multiple communication protocols are used to connect the smart device. Wi-Fi, Xbee, ZigBee, Bluetooth, and LoRaWAN are some of the communication channels utilized for connectivity by devices using some IoT platform.In order to enable the development of smart services for IoT platforms, there are solutions by different vendors to connect between IoT devices. For example, multiple IoT platforms are available in the market namely IoTivity platform developed by Open Connectivity Foundation (OCF), AllJoyn platform from All Seen Alliance, Weave made by Google, and Home Kit by Apple. In view of such segmentation of IoT platforms, IoT Application’s development has been made complex, where IoT device and accompanying application compatibility with available platforms requires support for multiple protocols.To simplify the complexity introduced by multiple platforms, M2M [4] International standard was already proposed as the bridge for integrating IoT protocols. In our paper, we implement a proxy web service using Windows Communication Foundation (WCF) as a way to translate communication in one IoT protocol to another. In our implementation of middleware, we allowed the MQTT broker to accept messages, which were passed, to the Web Service from various devices over Hyper Text Protocol’s POST or GET Commands. Bridging between WCF Web Service and MQTT broker was enabled with duplex communication. Hence, devices supporting either HTTP protocol or MQTT protocol were able to communicate transparently.

Development of Virtual Resource Based IoT Proxy for Bridging Heterogeneous Web Services in IoT Networks.

The Internet of Things is comprised of heterogeneous devices, applications, and platforms using multiple communication technologies to connect the Internet for providing seamless services ubiquitously. With the requirement of developing Internet of Things products, many protocols, program libraries, frameworks, and standard specifications have been proposed. Therefore, providing a consistent interface to access services from those environments is difficult. Moreover, bridging the existing web services to sensor and actuator networks is also important for providing Internet of Things services in various industry domains. In this paper, an Internet of Things proxy is proposed that is based on virtual resources to bridge heterogeneous web services from the Internet to the Internet of Things network. The proxy enables clients to have transparent access to Internet of Things devices and web services in the network. The proxy is comprised of server and client to forward messages for different communication environments using the virtual resources which include the server for the message sender and the client for the message receiver. We design the proxy for the Open Connectivity Foundation network where the virtual resources are discovered by the clients as Open Connectivity Foundation resources. The virtual resources represent the resources which expose services in the Internet by web service providers. Although the services are provided by web service providers from the Internet, the client can access services using the consistent communication protocol in the Open Connectivity Foundation network. For discovering the resources to access services, the client also uses the consistent discovery interface to discover the Open Connectivity Foundation devices and virtual resources.

Realising Interoperability Between OPC UA and OCF

The paper deals with the interoperability issue inside Industry 4.0. Definition and adoption of communication standards are of paramount importance to improve the interoperability of industrial applications. For this reason, during the last few years, different organisations have developed reference architectures to align standards in the context of the fourth industrial revolution. Among them, an important role is played by OPC UA international standard (IEC 62541). Application in industrial contexts of modern Information & Communication Technology (ICT) concepts, such as Internet of Things (IoT), is a key-point in Industry 4.0. For this reason, the current literature presents several proposals aimed to improve interoperability between reference standards in Industry 4.0 and IoT ecosystems. The paper proposes a solution towards interoperability between OPC UA and IoT, based on the mapping of OPC UA and Open Connectivity Foundation (OCF) specifications defined very recently to enable the interoperability inside the IoT ecosystem. Although other examples of integration of OPC UA with the IoT are present in the current literature, the proposal is original as interoperability between OPC UA and OCF has not been treated until now. The proposal may also have a potential impact on the current definition of OCF specifications, as it will be pointed out in the paper.