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Internet of Things, , 15CS81, , What Is IoT?, IoT is a technology transition in which devices will allow us to sense and control the physical, world by making objects smarter and connecting them through an intelligent network., GOAL: The basic premise and goal of IoT is to “connect the unconnected.” This means that, objects that are not currently joined to a computer network, namely the Internet, will be conn, ected so that they can communicate and interact with people and other objects., When objects and machines can be sensed and controlled remotely across a network, a tighter, integration between the physical world and computers is enabled., This allows for improvements in the areas of efficiency, accuracy, automation, and the enable, ment of advanced applications., GENESIS OF IOT, The person credited with the creation of the term “Internet of Things” is Kevin Ashton. While, working for Procter & Gamble in 1999, Kevin used this phrase to explain a new idea related, to linking the company’s supply chain to the Internet., , the evolution of the Internet can be categorized into four phases. Each of these phases has, had a profound impact on our society and our lives. These four phases are further defined in, Table below., , Department of CSE, ICEAS, Bangalore, , Page 2
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Internet of Things, , 15CS81, , IOT AND DIGITIZATION, IoT and digitization are terms that are often used interchangeably. In most contexts,, this duality is fine, but there are key differences to be aware of., At a high level, IoT focuses on connecting “things,” such as objects and machines, to, a computer network, such as the Internet. IoT is a well-understood term used across the, industry as a whole. On the other hand, digitization can mean different things to different, people but generally encompasses the connection of “things” with the data they generate and, the business insights that result., Digitization, as defined in its simplest form, is the conversion of information into a, digital format. Digitization has been happening in one form or another for several decades., For example, the whole photography industry has been digitized. Pretty much everyone has, digital cameras these days, either standalone devices or built into their mobile phones., Almost no one buys film and takes it to a retailer to get it developed. The digitization of, photography has completely changed our experience when it comes to capturing images., , CONVERGENCE OF IT AND OT, Until recently, information technology (IT) and operational technology (OT) have for, the most part lived in separate worlds. IT supports connections to the Internet along with, related data and technology systems and is focused on the secure flow of data across an, organization. OT monitors and controls devices and processes on physical operational, systems. These systems include assembly lines, utility distribution networks, production, facilities, roadway systems, and many more. Typically, IT did not get involved with the, production and logistics of OT environments., Management of OT is tied to the lifeblood of a company. For example, if the network, connecting the machines in a factory fails, the machines cannot function, and production may, come to a standstill, negatively impacting business on the order of millions of dollars. On the, other hand, if the email server (run by the IT department) fails for a few hours, it may irritate, people, but it is unlikely to impact business at anywhere near the same level. Table below, highlights some of the differences between IT and OT networks and their various, challenges., , Department of CSE, ICEAS, Bangalore, , Page 3
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Internet of Things, , 15CS81, , IoT Network Architecture and Design, The unique challenges posed by IoT networks and how these challenges have driven new, architectural models., Drivers Behind New Network Architectures, Comparing IoT Architectures., A Simplified IoT Architecture, The Core IoT Functional Stack, IoT Data Management and Compute Stack, , DRIVERS BEHIND NEW NETWORK ARCHITECTURES, This begins by comparing how using an architectural blueprint to construct a house is similar, to the approach we take when designing a network. Take a closer look at some of the, differences between IT and IoT networks, with a focus on the IoT requirements that are, driving new network architectures, and considers what adjustments are needed., , Department of CSE, ICEAS, Bangalore, , Page 5
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Internet of Things, , 15CS81, , COMPARING IOT ARCHITECTURES, The oneM2M IoT Standardized Architecture, In an effort to standardize the rapidly growing field of machine-to-machine (M2M), communications, the European Telecommunications Standards Institute (ETSI) created the, M2M Technical Committee in 2008. The goal of this committee was to create a common, architecture that would help accelerate the adoption of M2M applications and devices. Over, time, the scope has expanded to include the Internet of Things., One of the greatest challenges in designing an IoT architecture is dealing with the, heterogeneity of devices, software, and access methods. By developing a horizontal platform, architecture, oneM2M is developing standards that allow interoperability at all levels of the, IoT stack, , The Main Elements of the oneM2M IoT Architecture, , The oneM2M architecture divides IoT functions into three major domains: the application, layer, the services layer, and the network layer, , , Applications layer: The oneM2M architecture gives major attention to connectivity, between devices and their applications. This domain includes the application-layer, protocols and attempts to standardize northbound API definitions for interaction with, business intelligence (BI) systems. Applications tend to be industry-specific and have, their own sets of data models, and thus they are shown as vertical entities., , , , Services layer: This layer is shown as a horizontal framework across the vertical, industry applications. At this layer, horizontal modules include the physical network, that the IoT applications run on, the underlying management protocols, and the, hardware. Examples include backhaul communications via cellular, MPLS networks,, VPNs, and so on. Riding on top is the common services layer., , , , Network layer: This is the communication domain for the IoT devices and endpoints., It includes the devices themselves and the communications network that links them., Embodiments of this communications infrastructure include wireless mesh, technologies, such as IEEE 802.15.4, and wireless point-to-multipoint systems, such, as IEEE 801.11ah., , Department of CSE, ICEAS, Bangalore, , Page 7
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Internet of Things, , 15CS81, , The IoT World Forum (IoTWF) Standardized Architecture, This publish a seven-layer IoT architectural reference model., , , While various IoT reference models exist, the one put forth by the IoT World Forum, offers a clean, simplified perspective on IoT and includes edge computing, data, storage, and access. It provides a succinct way of visualizing IoT from a technical, perspective. Each of the seven layers is broken down into specific functions, and, security encompasses the entire model., , Using this reference model, we are able to achieve the following:, 1., 2., 3., 4., 5., , Decompose the IoT problem into smaller parts, Identify different technologies at each layer and how they relate to one another, Define a system in which different parts can be provided by different vendors, Have a process of defining interfaces that leads to interoperability, Define a tiered security model that is enforced at the transition points between levels, , Layer 1: Physical Devices and Controllers Layer, The first layer of the IoT Reference Model is the physical devices and, controllers layer. This layer is home to the “things” in the Internet of Things,, including the various endpoint devices and sensors that send and receive information., The size of these “things” can range from almost microscopic sensors to giant, machines in a factory. Their primary function is generating data and being capable of, being queried and/or controlled over a network., , Department of CSE, ICEAS, Bangalore, , Page 8
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Internet of Things, , 15CS81, , Layer 2: Connectivity Layer, In the second layer of the IoT Reference Model, the focus is on connectivity., The most important function of this IoT layer is the reliable and timely transmission, of data. More specifically, this includes transmissions between Layer 1 devices and, the network and between the network and information processing that occurs at Layer, 3 (the edge computing layer)., ., , IoT Reference Model Connectivity Layer Functions, Layer 3: Edge Computing Layer, Edge computing is the role of Layer 3. Edge computing is often referred to as, the “fog” layer and is discussed in the section “Fog Computing,” later in this chapter., At this layer, the emphasis is on data reduction and converting network data flows, into information that is ready for storage and processing by higher layers. One of the, basic principles of this reference model is that information processing is initiated as, early and as close to the edge of the network as possible, , IoT Reference Model Layer 3 Functions, , Department of CSE, ICEAS, Bangalore, , Page 9
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Internet of Things, , 15CS81, , Another important function that occurs at Layer 3 is the evaluation of data to see if it, can be filtered or aggregated before being sent to a higher layer. This also allows for, data to be reformatted or decoded, making additional processing by other systems, easier. Thus, a critical function is assessing the data to see if predefined thresholds are, crossed and any action or alerts need to be sent., Upper Layers: Layers 4–7, The upper layers deal with handling and processing the IoT data generated by, the bottom layer. For the sake of completeness, Layers 4–7 of the IoT Reference, Model are summarized in Table ., , A SIMPLIFIED IOT ARCHITECTURE, , Simplified IoT Architecture, Department of CSE, ICEAS, Bangalore, , Page 10
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Internet of Things, , 15CS81, , The presentation of the Core IoT Functional Stack in three layers is meant to simplify, your understanding of the IoT architecture into its most foundational building blocks. The, network communications layer of the IoT stack itself involves a significant amount of detail, and incorporates a vast array of technologies., Data management is aligned with each of the three layers of the Core IoT Functional, Stack. The three data management layers are the edge layer (data management within the, sensors themselves), the fog layer (data management in the gateways and transit network),, and the cloud layer (data management in the cloud or central data center). An expanded view, of the IoT architecture presented as below:, , Expanded View of the Simplified IoT Architecture, The Core IoT Functional Stack can be expanded into sublayers containing greater, detail and specific network functions. For example, the communications layer is broken down, into four separate sublayers: the access network, gateways and backhaul, IP transport, and, operations and management sublayers., The applications layer of IoT networks is quite different from the application layer of, a typical enterprise network. Instead of simply using business applications, IoT often involves, a strong big data analytics component. One message that is stressed throughout this book is, that IoT is not just about the control of IoT devices but, rather, the useful insights gained, from the data generated by those devices. Thus, the applications layer typically has both, analytics and industry-specific IoT control system components., presented in Part II, and it gives you the tools you need to understand how these technologies, are applied in key industries in Part III., , THE CORE IOT FUNCTIONAL STACK, IoT networks are built around the concept of “things,” or smart objects performing, functions and delivering new connected services. These objects are “smart” because they use, a combination of contextual information and configured goals to perform actions., From an architectural standpoint, several components have to work together for an IoT, network to be operational:, Department of CSE, ICEAS, Bangalore, , Page 11
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Internet of Things, , 15CS81, , “Things” layer:, Communications network layer, Access network sublayer, Gateways and backhaul network sublayer, Network transport sublayer, IoT network management sublayer, Application and analytics layer, The following sections examine these elements and help you architect your IoT, communication network., Layer 1: Things: Sensors and Actuators Layer, “Smart Objects: The ‘Things’ in IoT,” provides more in-depth information about, smart objects. From an architectural standpoint, the variety of smart object types, shapes, and, needs drive the variety of IoT protocols and architectures. One architectural classification, could be:, Battery-powered or power-connected: This classification is based on whether the, object carries its own energy supply or receives continuous power from an external, power source., Mobile or static: This classification is based on whether the “thing” should move or, always stay at the same location. A sensor may be mobile because it is moved from, one object to another or because it is attached to a movin, Low or high reporting frequency: This classification is based on how often the, object should report monitored parameters. A rust sensor may report values once a, month. A motion sensor may report acceleration several hundred times per second., Simple or rich data: This classification is based on the quantity of data exchanged at, each report cycle, Report range: This classification is based on the distance at which the gateway is, located. For example, for your fitness band to communicate with your phone, it needs, to be located a few meters away at most., Object density per cell: This classification is based on the number of smart objects, (with a similar need to communicate) over a given area, connected to the same, gateway., Below figure provides some examples of applications matching the combination of mobility, and throughput requirements., , Example of Sensor Applications Based on Mobility and Throughput, Department of CSE, ICEAS, Bangalore, , Page 12
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Internet of Things, , 15CS81, , Layer 2: Communications Network Layer, Once you have determined the influence of the smart object form factor over its, transmission capabilities (transmission range, data volume and frequency, sensor density and, mobility), you are ready to connect the object and communicate., Compute and network assets used in IoT can be very different from those in IT environments., The difference in the physical form factors between devices used by IT and OT is obvious, even to the most casual of observers. What typically drives this is the physical environment in, which the devices are deployed. What may not be as inherently obvious, however, is their, operational differences. The operational differences must be understood in order to apply the, correct handling to secure the target assets., Access Network Sublayer, There is a direct relationship between the IoT network technology you choose and the, type of connectivity topology this technology allows. Each technology was designed with a, certain number of use cases in mind (what to connect, where to connect, how much data to, transport at what interval and over what distance). These use cases determined the frequency, band that was expected to be most suitable, the frame structure matching the expected data, pattern (packet size and communication intervals), and the possible topologies that these use, cases illustrate., One key parameter determining the choice of access technology is the range between the, smart object and the information collector. Figure 2-9 lists some access technologies you may, encounter in the IoT world and the expected transmission distances., , Access Technologies and Distances, , Department of CSE, ICEAS, Bangalore, , Page 13
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Internet of Things, , 15CS81, , Range estimates are grouped by category names that illustrate the environment or the, vertical where data collection over that range is expected. Common groups are as, follows:, PAN (personal area network): Scale of a few meters. This is the personal space around a, person. A common wireless technology for this scale is Bluetooth., HAN (home area network): Scale of a few tens of meters. At this scale, common wireless, technologies for IoT include ZigBee and Bluetooth Low Energy (BLE)., NAN (neighborhood area network): Scale of a few hundreds of meters. The term NAN is, often used to refer to a group of house units from which data is collected., FAN (field area network): Scale of several tens of meters to several hundred meters. FAN, typically refers to an outdoor area larger than a single group of house units. The FAN is often, seen as “open space” (and therefore not secured and not controlled)., LAN (local area network): Scale of up to 100 m. This term is very common in, networking, and it is therefore also commonly used in the IoT space when standard, networking technologies (such as Ethernet or IEEE 802.11) are used., Similar ranges also do not mean similar topologies. Some technologies offer flexible, connectivity structure to extend communication possibilities:, Point-to-point topologies, Point-to-multipoint, , Star and Clustered Star Topologies, , Department of CSE, ICEAS, Bangalore, , Page 14
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Internet of Things, , 15CS81, , Comparison of the main solutions from an architectural angle., , Architectural Considerations for WiMAX and Cellular Technologies, Layer 3: Applications and Analytics Layer, Once connected to a network, your smart objects exchange information with other, systems. As soon as your IoT network spans more than a few sensors, the power of the, Internet of Things appears in the applications that make use of the information exchanged, with the smart objects., , Department of CSE, ICEAS, Bangalore, , Page 15
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Internet of Things, , 15CS81, , Analytics Versus Control Applications, Multiple applications can help increase the efficiency of an IoT network. Each, application collects data and provides a range of functions based on analyzing the collected, data. It can be difficult to compare the features offered. From an architectural standpoint, one, basic classification can be as follows:, Analytics application: This type of application collects data from multiple smart objects,, processes the collected data, and displays information resulting from the data that was, processed. The display can be about any aspect of the IoT network, from historical reports,, statistics, or trends to individual system states. The important aspect is that the application, processes the data to convey a view of the network that cannot be obtained from solely, looking at the information displayed by a single smart object., Control application: This type of application controls the behavior of the smart object or, the behavior of an object related to the smart object. For example, a pressure sensor may be, connected to a pump. A control application increases the pump speed when the connected, sensor detects a drop in pressure. Control applications are very useful for controlling complex, aspects of an IoT network with a logic that cannot be programmed inside a single IoT object,, either because the configured changes are too complex to fit into the local system or because, the configured changes rely on parameters that include elements outside the IoT object., , Data Versus Network Analytics, Analytics is a general term that describes processing information to make sense of collected, data. In the world of IoT, a possible classification of the analytics function is as follows:, Data analytics: This type of analytics processes the data collected by smart objects and, combines it to provide an intelligent view related to the IoT system. At a very basic level, a, dashboard can display an alarm when a weight sensor detects that a shelf is empty in a store., In a more complex case, temperature, pressure, wind, humidity, and light levels collected, from thousands of sensors may be combined and then processed to determine the likelihood, of a storm and its possible path ., Network analytics: Most IoT systems are built around smart objects connected to the, network. A loss or degradation in connectivity is likely to affect the efficiency of the system., Such a loss can have dramatic effects. For example, open mines use wireless networks to, automatically pilot dump trucks. A lasting loss of connectivity may result in an accident or, degradation of operations efficiency (automated dump trucks typically stop upon connectivity, loss). On a more minor scale, loss of connectivity means that data stops being fed to your, data analytics platform, and the system stops making intelligent analyses of the IoT system., Data Analytics Versus Business Benefits, Data analytics is undoubtedly a field where the value of IoT is booming. Almost any object, can be connected, and multiple types of sensors can be installed on a given object. Collecting, and interpreting the data generated by these devices is where the value of IoT is realized., , Smart Services, , , The ability to use IoT to improve operations is often termed “smart services.” This, term is generic, and in many cases the term is used but its meaning is often stretched, to include one form of service or another where an additional level of intelligence is, provided., , Department of CSE, ICEAS, Bangalore, , Page 16
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Internet of Things, , 15CS81, , , , Smart services can also be used to measure the efficiency of machines by detecting, machine output, speed, or other forms of usage evaluation., , , , Smart services can be integrated into an IoT system. For example, sensors can be, integrated in a light bulb. A sensor can turn a light on or off based on the presence of, a human in the room., , IOT DATA MANAGEMENT AND COMPUTE STACK, This model also has limitations. As data volume, the variety of objects connecting to, the network, and the need for more efficiency increase, new requirements appear, and those, requirements tend to bring the need for data analysis closer to the IoT system. These new, requirements include the following:, Minimizing latency: Milliseconds matter for many types of industrial systems, such as, when you are trying to prevent manufacturing line shutdowns or restore electrical service., Analyzing data close to the device that collected the data can make a difference between, averting disaster and a cascading system failure., Conserving network bandwidth: Offshore oil rigs generate 500 GB of data weekly., Commercial jets generate 10 TB for every 30 minutes of flight. It is not practical to transport, vast amounts of data from thousands or hundreds of thousands of edge devices to the cloud., Nor is it necessary because many critical analyses do not require cloud-scale processing and, storage., Increasing local efficiency: Collecting and securing data across a wide geographic area, with different environmental conditions may not be useful. The environmental conditions in, one area will trigger a local response independent from the conditions of another site, hundreds of miles away. Analyzing both areas in the same cloud system may not be, necessary for immediate efficiency., ., , The Traditional IT Cloud Computing Model, , Department of CSE, ICEAS, Bangalore, , Page 17
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Internet of Things, , 15CS81, , IoT systems function differently. Several data-related problems need to be addressed:, Bandwidth in last-mile IoT networks is very limited. When dealing with thousands/millions, of devices, available bandwidth may be on order of tens of Kbps per device or even less., Latency can be very high. Instead of dealing with latency in the milliseconds range, large, IoT networks often introduce latency of hundreds to thousands of milliseconds., Network backhaul from the gateway can be unreliable and often depends on 3G/LTE or, even satellite links. Backhaul links can also be expensive if a per-byte data usage model is, necessary., The volume of data transmitted over the backhaul can be high, and much of the data may, not really be that interesting (such as simple polling messages)., Big data is getting bigger. The concept of storing and analyzing all sensor data in the cloud, is impractical. The sheer volume of data generated makes real-time analysis and response to, the data almost impossible., Fog Computing, The solution to the challenges mentioned in the previous section is to distribute data, management throughout the IoT system, as close to the edge of the IP network as possible., The best-known embodiment of edge services in IoT is fog computing. Any device with, computing, storage, and network connectivity can be a fog node. Examples include industrial, controllers, switches, routers, embedded servers, and IoT gateways. Analyzing IoT data close, to where it is collected minimizes latency, offloads gigabytes of network traffic from the core, network, and keeps sensitive data inside the local network., , The IoT Data Management and Compute Stack with Fog Computing, Department of CSE, ICEAS, Bangalore, , Page 18
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Internet of Things, , 15CS81, , Fog services are typically accomplished very close to the edge device, sitting as close, to the IoT endpoints as possible. One significant advantage of this is that the fog node has, contextual awareness of the sensors it is managing because of its geographic proximity to, those sensors. For example, there might be a fog router on an oil derrick that is monitoring all, the sensor activity at that location. Because the fog node is able to analyze information from, all the sensors on that derrick, it can provide contextual analysis of the messages it is, receiving and may decide to send back only the relevant information over the backhaul, network to the cloud. In this way, it is performing distributed analytics such that the volume, of data sent upstream is greatly reduced and is much more useful to application and analytics, servers residing in the cloud., Fog applications are as diverse as the Internet of Things itself. What they have in, common is data reduction—monitoring or analyzing real-time data from network-connected, things and then initiating an action, such as locking a door, changing equipment settings,, applying the brakes on a train, zooming a video camera, opening a valve in response to a, pressure reading, creating a bar chart, or sending an alert to a technician to make a preventive, repair., The defining characteristic of fog computing are as follows:, Contextual location awareness and low latency: The fog node sits as close to the IoT, endpoint as possible to deliver distributed computing., Geographic distribution: In sharp contrast to the more centralized cloud, the services and, applications targeted by the fog nodes demand widely distributed deployments., Deployment near IoT endpoints: Fog nodes are typically deployed in the presence of a, large number of IoT endpoints. For example, typical metering deployments often see 3000 to, 4000 nodes per gateway router, which also functions as the fog computing node., Wireless communication between the fog and the IoT endpoint: Although it is possible, to connect wired nodes, the advantages of fog are greatest when dealing with a large number, of endpoints, and wireless access is the easiest way to achieve such scale., Use for real-time interactions: Important fog applications involve real-time interactions, rather than batch processing. Preprocessing of data in the fog nodes allows upper-layer, applications to perform batch processing on a subset of the data., Edge Computing, Fog computing solutions are being adopted by many industries, and efforts to develop, distributed applications and analytics tools are being introduced at an accelerating pace. The, natural place for a fog node is in the network device that sits closest to the IoT endpoints, and, these nodes are typically spread throughout an IoT network, Note, Edge computing is also sometimes called “mist” computing. If clouds exist in the sky,, and fog sits near the ground, then mist is what actually sits on the ground. Thus, the concept, of mist is to extend fog to the furthest point possible, right into the IoT endpoint device itself., The Hierarchy of Edge, Fog, and Cloud, It is important to stress that edge or fog computing in no way replaces the cloud., Rather, they complement each other, and many use cases actually require strong cooperation, between layers. In the same way that lower courts do not replace the supreme court of a, Department of CSE, ICEAS, Bangalore, , Page 19
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Internet of Things, , 15CS81, , country, edge and fog computing layers simply act as a first line of defense for, filtering, analyzing, and otherwise managing data endpoints. This saves the cloud from being, queried by each and every node for each event., , Distributed Compute and Data Management Across an IoT System, , From an architectural standpoint, fog nodes closest to the network edge receive the data from, IoT devices. The fog IoT application then directs different types of data to the optimal place, for analysis:, The most time-sensitive data is analyzed on the edge or fog node closest to the things, generating the data., Data that can wait seconds or minutes for action is passed along to an aggregation node for, analysis and action., Data that is less time sensitive is sent to the cloud for historical analysis, big data analytics,, and long-term storage. For example, each of thousands or hundreds of thousands of fog nodes, might send periodic summaries of data to the cloud for historical analysis and storage., In summary, when architecting an IoT network, you should consider the amount of data to be, analyzed and the time sensitivity of this data. Understanding these factors will help you, decide whether cloud computing is enough or whether edge or fog computing would improve, your system efficiency. Fog computing accelerates awareness and response to events by, eliminating a round trip to the cloud for analysis. It avoids the need for costly bandwidth, additions by offloading gigabytes of network traffic from the core network. It also protects, sensitive IoT data by analyzing it inside company walls., , Department of CSE, ICEAS, Bangalore, , Page 20
