MIDDLEWARE FOR INTERNET OF THINGS. Dr Gaurav Bajpai Head, Computer and So7ware Engineering College of Science and Technology University of Rwanda

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1 MIDDLEWARE FOR INTERNET OF THINGS By Dr Gaurav Bajpai Head, Computer and So7ware Engineering College of Science and Technology University of Rwanda

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8 Defini6on of IoT InternaDonal TelecommunicaDon Union (ITU) defines IoT as A global infrastructure for the Informa4on Society, enabling advanced services by interconnec4ng (physical and virtual) things based on, exis4ng and evolving, interoperable informa4on and communica4on technologies

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10 Internet of Things- Architecture (IoT- A) Defines it as The idea of a globally interconnected con4nuum of devices, objects and things in general emerged with the RFID technology, and this concept has considerably been extended to the current vision that envisages a plethora of heterogeneous objects interac4ng with the physical environment.

11 Layered Architecture of the Internet of Things (IoT).

12 Edge Technology layer This is a hardware layer that consists of embedded systems, RFID tags, sensor networks and all of the other sensors in different forms. This hardware layer can perform several functions, such as collecting information from a system or an environment, processing information and supporting communication. Access Gateway layer This layer is concerned with data handling, and is responsible for publishing and subscribing the services that are provided by the Things, message routing, and hovelling the communication between platforms. Middleware layer This layer has some critical functionalities, such as aggregating and filtering the received data from the hardware devices, performing information discovery and providing access control to the devices for applications. Application layer This layer is responsible for delivering various application services. These services are provided through the middleware layer to different applications and users in IoTbased systems. The application services can be used in different industries such as, logistics, retail, healthcare, etc.

13 Func6onal components of a middleware for IoT- based systems

14 1. Interface protocols This component is in charge of providing technical interoperability. Interoperability in the context of Interface protocols means: the ability of two systems to interoperate by using the same communica4on protocols. According to ETSI (European TelecommunicaDons Standards InsDtute) technical interoperability is defined as the associa4on of hardware or sodware components, systems and plaeorms that enable machine- to- machine communica4on to take place. This kind of interoperability is oden centered on (communica4on) protocols and the infrastructure needed for those protocols to operate.

15 2. Device Abstrac6on (DA) This component is responsible for providing an abstract format to facilitate the interacdon of the applicadon components with devices. This abstracdon provides syntac4c and seman4c interoperability, Syntac4c interoperability is associated with data formats. The messages transferred by communicadon protocols must have a well- defined syntax and encoding format, which can be represented by using high- level transfer syntaxes such as, HTML and XML. Seman4c interoperability is usually associated with the meaning of the content of message which is understandable for human. Thus, interoperability on this level means that there is a common understanding among people on the meaning of the content (informadon) being exchanged among them.

16 3. Central control, Context detec6on & Management (CCM) Context characterizes the situadon of an endty, which can be a place, a person or an object that is relevant to the user, applicadons and their interacdons. The CCM funcdonal component is responsible to support context- aware computadon that is a computadonal style that take to account the context of the enddes that interact with the system. A middleware for IoT- based systems must be context- aware to work in smart environments.

17 Context- awareness includes two func6onali6es: 1) Context detecdon, which consists of collecdng data from resources, and selecdng the informadon that can have an impact on the computadon. 2) Context processing, to use the gathered informadon to perform a task or make a decision.

18 4. Applica6on Abstrac6on This funcdonal component provides an interface for both high- level applicadons and end users to interact with devices. For instance, this interface can be a RESTful interface or can be implemented with some query- based language.

19 Review of IoT- based Middleware The term Internet of Things (IoT) refers to a wide set of applicadons and research areas such as, distributed compudng and knowledge management. Much of the IoT research is related to the field of pervasive compu4ng. World Wide Web ConsorDum (W3C) defines pervasive compu4ng as a vision about our future compu4ng life style. In this vision, computer systems will be seamlessly integrated into our everyday life, an4cipa4ng our needs and providing relevant services and informa4on for us in an any4me- and- any- where fashion. Pervasive Compu4ng is all about making the human's life easier by exploi4ng the available compu4ng technologies. This modvates sciendsts to develop new technologies for the everyday people's lives.

20 Typical IoT Middleware HYDRA it is the most popular and well documented middleware in comparer to the mendoned middleware. AURA is middleware focus on elaboradon and manipuladon of the gathered data from devices. Its aim is to provide ease of configuradon and deployment for end user and developer. Since to meet this goal, we require to facilitate the gathered data manipuladon, AURA that was the only middleware among that considered the data manipuladon. TinyDB focus on gathering data from devices. Since in an IoT- based system we need to gather data from environment through different devices, TinyDB that is a popular middleware. WiseMID is the only middleware among the reviewed middleware that is specific for energy saving purpose. As saving the energy of devices is important issue.

21 HYDRA Components inside and outside of Hydra middleware

22 AURA The components of the AURA framework architecture and their interacdons

23 TinyDB TinyDB middleware was the first project to propose the idea of abstracdng from devices. TinyDB allows end- users to interact with devices without knowing about the details of the devices specificadon, such as the communicadon protocols that are supported by these devices. Monitoring Queries It asks the value of one or more a^ributes periodically and condnuously, such as, e.g., repordng the temperature of a warehouse every hour. Network Health Queries It provides informadon about the network itself. For instance, selecdng neighbouring nodes, with a ba^ery lifedme larger than a threshold. Exploratory Query It shows the status of a specific node or a set of nodes at a specific Dme, such as, e.g., selecdng the temperature of the sensor with same specific id. Actua>on Query This kind of query can be used to ask for a physical acdon. For instance, an enduser of a system wants to turn off a fan in a room when the temperature of the room is lower than a threshold.

24 WISeMid WISeMid is an energy- aware middleware for integradng wireless sensor networks and Internet. In an IoT- based system, saving energy in interacdon among devices is important, because they usually have limited power suppliers. Also, IoT- based system is IP- based communicadon. Therefore, as the WISeMid middleware considers both Ipbased communicadon and energy awareness factors.

25 Aggrega>on service The goal of the data aggregadon service is to aggregate correlated or redundant data, and reduce the overall size of transferred data in a network. In this way, we can decrease the network traffic and save energy by decreasing the interacdons with devices. In this service, a user sends one request and receives an answer based on an aggregadon of the last values of the requested devices. In this way the number of transacdon decreases and energy can be saved. Reply Storage Timeout This service stops sending the same messages with the same parameters. For instance, if the sensed data of a device is fixed for a specific period of Dme, we can send only one request to the considered device, and then use the reply message to answer to all of the equivalent request messages arriving during that specific period. Therefore, WISeMid prevents the system from geang informadon from sensors when the data is sdll up- to- date. Atomic Type Conversion This service decreases the size of messages in an IoT- based system. For instance, if we define an integer data type for a field that gets a numeric value like 1 in this case, we many bytes are unnecessarily used. To save bytes, the argument format can convert from Integer to Short. Thus, WISeMid removes unnecessary bytes from messages. Invoca>on asynchrony paderns This service provides four pa^erns to handle the end- user requests in an asynchronous way. These pa^erns prevent the system waste Dme with blocking, when requests can be handled in an asynchronous way.

26 WISeMid architecture

27 Compara6ve Analysis of the Middleware

28 IoT- middleware comparison.

29 IoT- middleware Interfaces

30 Thank You