Bourgogne Franche-Comté, Dijon, France
1.1. Introduction
The Internet of Things (IoT) is now an integral part of our daily life. By 2020, there will be over 20 billion connected digital and electronic devices, which works out to about two devices per human being on Earth (Nordrum 2016). The IoT will thus have a significant impact on human life and will improve quality of life. The future growth of the IoT will lead to advanced use of technology in order to facilitate accomplishing daily human tasks. Consequently, improving corresponding services is an important challenge that must be faced in order to allow the expansion of this environment. In this context, it is expected that there will be a better user experience that will make up for the limitations experienced when using IoT services. User experience may translate to a service level that includes the expected Quality of Service (QoS) and also the expected level of security and privacy offered by the IoT environment. The objects connected to the IoT have certain restrictions in terms of memory, computing capacity and energy consumption. However, existing QoS security and privacy protection mechanisms do not take these constraints into consideration. Thus, it is primordial that we design and develop new QoS and security mechanisms or adapt and improve existing mechanisms in the context of the IoT.
In this chapter, we will first introduce, in section 1.2, definitions related to the IoT environment. We will then describe, in section 1.3, the architectures proposed by different standardization bodies and the fields of application of the IoT. section 1.4 introduces security management as well as the management of privacy protection in the IoT through the motivations, challenges and different security services that must be considered in this kind of environment. section 1.5 describes QoS management by highlighting the needs and requirements of every layer of the IoT architecture in terms of QoS as well as the proposed QoS mechanisms that will respond to these. section 1.6 defines our framework using a three-layer IoT architecture and a QoS-based access mechanism concerning the lowest level of this architecture. Finally, section 1.7 presents conclusions and perspectives related to service level management in an IoT environment.
1.2. IoT: definitions
Various standardization bodies have worked on the IoT in order to specify the definitions, architecture, recommendations and the fields of application for this new paradigm. The ITU–T (International Telecommunication Union– Telecommunication Standardization Sector) is a standardization body that works on the IoT environment and its different fields of applications through the SG20 work group. According to the ITU-T document Y.2060, the IoT is a ubiquitous network that is available everywhere, anytime and to anyone (ITU-T 2012). The IoT is a global infrastructure for the information society that makes it possible to offer advanced services by interconnecting objects using various communication technologies (Minerva et al. 2015). Further, in ISO/IEC (2015a), the ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) provides a definition and specification for the vocabulary used within the IoT environment. According to this, the IoT is a network of physical objects that collect and transmit data. It is an infrastructure made up of interconnected objects, humans and information resources that make it possible to process data collected by the objects and then react as a consequence (ISO/IEC 2015a; International Electrotechnical Commission 2017b). According to the Internet Engineering Task Force (IETF), the general idea behind the IoT is to connect objects in order to provide contextual services across different technologies, thereby offering a service available anywhere and at any time (Minerva et al. 2015). The IETF considers the IoT to be a network of interconnected objects that can be addressed uniquely and that use standardized protocols for communication between the objects (Lee et al. 2012). Further, the IETF and ISO/IEC take different requirements into consideration in the IoT environment, such as auto-configuration, unique identification, interfaces standardization, connectivity, reliability and mobility.
We propose a definition that brings together information from all the definitions discussed above: the IoT is a global infrastructure that interconnects objects (which are identified uniquely) and humans to offer advanced, autonomous services via smart interfaces. It must be noted that the unique identification allows the identity of the objects to be verified and enables data processing based on the source of the data.
1.3. IoT: an overview
1.3.1. IoT architectures
Standardization bodies and research projects have introduced various architectures for the IoT. In the following sections, we describe two examples of proposed architectures for the IoT.
1.3.1.1. The ITU-T reference model
The ITU-T proposed a reference model for the IoT that is based on multiple layers (ITU-T 2012). This reference model (see Figure 1.1) defines four horizontal layers (application, support, network and devices) and two vertical layers (management and security). The application layer includes IoT applications and services. Next, the Service Support and Application Support Layer defines the capacities for generic support that are common to all applications, such as data processing and storage. This also includes specific support capacities that respond to the needs of a particular application. The Network Layer offers two services. First there are network capacities, which ensure that connectivity, mobility management, authentication, authorization and accounting functions are all monitored. Second, there are transport capacities that control the routing of data coming from applications or information from the monitoring and management of the environment. The Device Layer defines the capacities of each connected object and device as well as the capacities of the communication gateways.
The vertical layers define the generic management capacities (management of objects, network, traffic and congestion) as well as the security capacities (authorization, authentication, integrity and privacy protection). Further, these vertical layers introduce specific capacities that are dependent on the type of IoT application being considered.
Figure 1.1. The ITU-T architecture of the Internet of Things (ITU-T 2012). For a color version of this figure, see www.iste.co.uk/mbarek/service.zip
1.3.1.2. The IIC architecture
The Industrial Internet Consortium is a consortium of several well-known industrial groups in the IT world, such as IBM, HUAWEI and Intel. Through the Industrial Internet Reference Architecture report, this consortium puts forth a system architecture that is applicable to the IoT. This three-tiered architecture is based on three vertical layers or three levels (see Figure 1.2) (Lin et al. 2015).
The Edge Tier corresponds to all the nodes that collect data from proximity networks. This layer makes it possible to implement all control functions. Then comes the Platform Tier, which receives, processes and transmits control commands to the Edge Tier. This layer also enables the processing, analysis and running of operations on data collected from objects, before transmitting them in the opposite direction, toward the Enterprise Tier. The Enterprise Tier takes decisions and carries out the role of an interface with the end-user. It thus includes applications that allow control commands to be generated and to be sent to the Platform Tier. The different layers in this architecture are interconnected via access networks and service networks.
