Chapter 2
IoT Fundamentals
In this chapter, we will discuss about the fundamental concepts in IoT sys- tems. This includes, devices, gateways, and networks and also different IoT applications and use cases.
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18 CHAPTER 2. IOT FUNDAMENTALS 2.1 A 4 Stage IoT Architecture
An IoT system have generally 4 major stages which are illustrated in Fig. 2.1. Stage 1 of an IoT architecture consists of the networked things, typically wireless
Figure 2.1: A 4 stage IoT Architecture.
sensors and actuators. Stage 2 is the gateway which gathers and aggregate data. Edge IT system in Stage 3, performs preprocessing of the data before sending it to the cloud. In Stage 4, the data is analyzed, managed, and stored on data center systems. In the following we give some details of each stage of an IoT architecture. Try to identify these 4 stages in the application described in this
video u.
2.1.1 IoT Devices
A device is a hardware unit that can sense aspects of its environment and/or actuate, i.e. perform tasks in its environment.
Sensors collect data from the environment or object under measurement and turn it into useful data. Think of the specialized structures in your cell phone that detect the directional pull of gravityand the phone’s relative position to the thing we call the earthand convert it into data that your phone can use to orient the device. Actuators can also intervene to change the physical conditions that generate the data. An actuator might, for example, shut off a power supply, adjust an air flow valve, or move a robotic gripper in an assembly process.
Some data processing can also occur in the sensor. But it is limited by the processing power available on each IoT device. The more you wait, the more deep insight you can get from your data. The more immediate the need for information, the closer to the end devices your processing needs to be. This video shows
What is an IoT device?
An IoT device is any nonstandard computing device that connects wirelessly to a network and has the ability to transmit data; these are the things in the Internet of Things.
IoT devices are part of a scenario in which every device talks to every other related device in an environment to automate home and industry and com-
The Thing
Sensors/Actuators
Internet Gateways, Data Aquistion
Edge IT
Data Center/Cloud
2.1. A 4 STAGE IOT ARCHITECTURE 19 municate more and more usable data to users, businesses and other interested
parties.
Have a look at this video u and think about IoT devices around you.
Classes of IoT Devices
We can also classify the devices based on the service they are providing
• Basic Devices: Devices that only provide the basic services of sensor readings and/or actuation tasks, and in some cases limited support for user interaction. LAN communication is supported via wired or wireless technology, thus a gateway is needed to provide the WAN connection.
• Advanced Devices: In this case the devices also host the application logic and a WAN connection. They may also feature device management and an execution environment for hosting multiple applications. Gateway devices are most likely to fall into this category.
Requirements for IoT Devices
The size, weight, power and cost demands for the IoT ecosystems will force the creation of a new paradigm for the hardware.
• Device Cost: If todays hardware costs 10apiecef ora100milliondevicemarket, thenthesamef unctionmayhavetob to address a 20 to 50 billion device market.
• Power Efficiency: Improved power efficiency, smart power management, energy harvesting and wireless power transmission will all need to be in- vestigated and made viable for IoT applications. In todays hardware, mil- liwatt dissipation may be sufficient. In the IoT world of 2020, microwatts or even nanowatt power dissipation will be required.
• Duty Cylcing: In many sensor applications, the IoT device must operate at a very low duty cycle; waking up for milliseconds to perform its function, transmit its data payload and then go back to sleep.
Other important IC technologies that will need attention include power convert- ers, micro-controllers such as Raspberry Pi, ARM, Arduino and Intels Edison platform.
Useful readings
The Hardware Enablers for the Internet of Things – Part I n
The Hardware Enablers for the Internet of Things Part II (More than
Moore) n
20 CHAPTER 2. IOT FUNDAMENTALS 2.1.2 Gateway
The data from the sensors starts in analog form. That data needs to be ag- gregated and converted into digital streams for further processing downstream. Data acquisition systems (DAS) perform these data aggregation and conversion functions. The DAS connects to the sensor network, aggregates outputs, and performs the analog-to-digital conversion. The Internet gateway receives the aggregated and digitized data and routes it over Wi-Fi, wired LANs, or the Internet, to Stage 3 systems for further processing.
Stage 2 systems often sit in close proximity to the sensors and actuators. For example, a pump might contain a half-dozen sensors and actuators that feed data into a data aggregation device that also digitizes the data. This device might be physically attached to the pump. An adjacent gateway device or server would then process the data and forward it to the Stage 3 or Stage 4 systems.
A gateway serves as a translator between different protocols, e.g. between IEEE 802.15.4 or IEEE 802.11, to Ethernet or cellular. The main roles of a Gateway are explained next:
1. Data management: Typical functions for data management include per- forming sensor readings and caching this data, as well as filtering, con- centrating, and aggregating the data before transmitting it to back-end servers.
2. Local applications: Examples of local applications that can be hosted on a gateway include closed loops, home alarm logic, and ventilation control, or the data management. The benefit of hosting this logic on the gateway instead of in the network is to avoid downtime in case of WAN connection failure, minimize usage of costly cellular data, and reduce latency.
3. Device management (DM) is an essential part of the IoT and provides efficient means to perform many of the management tasks for devices
2.1.3
• Provisioning : Initialization (or activation) of devices in regards to configuration and features to be enabled.
• Device Configuration : Management of device settings and parame- ters.
• Software Upgrades : Installation of firmware, system software, and applications on the device.
• Fault Management : Enables error reporting and access to device status.
Edge IT
Once IoT data has been digitized and aggregated, it’s ready to cross into the realm of IT. However, the data may require further processing before it enters the data center. This is where edge IT systems, which perform more analysis,
2.1. A 4 STAGE IOT ARCHITECTURE 21
come into play. Edge IT processing systems may be located in remote offices or other edge locations, but generally these sit in the facility or location where the sensors reside closer to the sensors, such as in a wiring closet.
Here’s another example: You might use machine learning at the edge to scan for anomalies that identify impending maintenance problems that require immediate attention. Then you could use visualization technology to present that information using easy-to-understand dashboards, maps, or graphs. Highly integrated compute systems, such as hyper-converged infrastructure, are ideally suited to these tasks because they’re relatively fast, and easy to deploy and manage remotely.
2.1.4 The data center and cloud
Data that needs more in-depth processing, and where feedback doesn’t have to be immediate, gets forwarded to physical data center or cloud-based systems, where more powerful IT systems can analyze, manage, and securely store the data. It takes longer to get results when you wait until data reaches Stage 4, but you can execute a more in-depth analysis, as well as combine your sensor data with data from other sources for deeper insights.
2.1.5 Network
A network is created when two or more computing devices exchange data or information.
When direct communication between two nodes over a physical medium is not possible, networking can allow for these devices to communicate over a number of hops. In order to achieve this, nodes of the network must have an awareness of all nodes in the network with which they can indirectly commu- nicate. This can be a direct connection over one link (edge, the transition or communication between two nodes over a link), or knowledge of a route to the desired (destination) node by communicating through cooperating nodes, over multiple edges.
Local Area Network
A Local Area Network (LAN) was traditionally distinguishable from a Wide Area Network (WAN) based on the geographic coverage requirements of the network, and the need for third party, or leased, communication infrastructure.
In the case of the LAN, a smaller geographic region is covered, such as a commercial building, an office block, or a home, and does not require any leased communications infrastructure. WANs provide communication links that cover longer distances, such as across metropolitan, regional, or by textbook definition, global geographic areas.
In practice, WANs are often used to link LANs and Metropolitan Area Networks (MAN) where LAN technologies cannot provide the communications
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ranges to otherwise interconnect and commonly to link LANs and devices (in- cluding smart phones, Wi-Fi routers that support LANs, tablets, and M2M devices) to the Internet.
2.1.6 Wide Area Networks
WANs are typically required to bridge the M2M Device Domain to the back- haul network, thus providing a proxy that allows information (data, commands, etc.) to traverse heterogeneous networks. This is seen as a core requirement to provide communications services between the M2M service enablement and the physical deployments of devices in the field. WAN is capable of providing the bi- directional communications links between services and devices. This, however, must be achieved by means of physical and logical proxy.
Watch this video u that summarize the devices and local networks for IoT.
2.2 IoT Main Application Areas 2.2.1 Massive IoT
Massive IoT applications typically sensors that report to the cloud on a regular basis. The end-to-end cost must be low enough for the business case to make sense. Here, the requirement is for low-cost devices with low energy consumption and good coverage. Massive IoT covers a wide range of applications, such as environmental monitoring, agriculture, transport and logistic, utilities, smart
cities, smart buildings, and consumers. The following video u shows one example of a massive IoT Application.
The key challenges for massive IoT are:
• Device cost clearly a key enabler for high-volume, mass-market applica- tions, enabling many of the use cases.
• Battery life many IoT devices will be battery-powered, and often the cost of replacing batteries in the field is not viable.
• Coverage deep indoor connectivity is a requirement for many applications in the utility area. Furthermore, regional (or even national or global) cov- erage is a prerequisite for many use cases, especially within the transport area.
• Scalability in order to enable a Massive IoT market, networks need to scale efficiently. The initial investment required for supporting a limited number of devices has to be manageable, while on the other hand, the network capacity must be easy to scale to handle thousands or millions of devices.
2.3. NEW CONCEPTS 23
• Diversity connectivity should be able to support diverse requirements from different use cases. One network supporting everything from sim- ple static sensors to tracking services, to applications requiring higher throughput and lower latency is essential in terms of total cost of owner- ship (TCO).
2.2.2 Critical IoT
Critical IoT applications will have very high demands for reliability, availability and low latency. These use cases are enabled by LTE or 5G Capabilities. Here, the volumes are typically much smaller, but the business value is significantly
higher. The following video u shows one example of a massive IoT Applica- tion. Critical IoT may include industrial IoT, remote surgery, robotic, smart grids, etc.
The key challenges for critical IoT are:
• High Reliability: Failure rate of less than 0.00001
• Low Latency: End-to-end latency of less than 1ms
• Availability: The service should be immediately available when needed.
2.3 New Concepts
In this section, we introduce some new terms and explain how they are related to IoT.
2.3.1 Machine-to-Machine (M2M) Communications
In the context of M2M, machines embedded with sensors and actuators are communication with each other or the data transport infrastrcuture via wired or wireless links. Machines usually have high processing capabilities! Autonomous communication is the main feature of M2M.
IoT is different than M2M as it aims to connect not only machines, but also humans and things.
Machine Type Communications (MTC) is heavily referred to in the ETSI documentation. MTC and M2M represent the same thing.
2.3.2 Device-to-device Communications
Device-to-Device (D2D) communications aims at connecting the devices in a local manner. The devices communicating with each other locally.
The main concept is to eliminate the need to send local information to the base station, when the destination is in the close vicinity of the sender. In this way, the devices can save energy and the load on the base station is reduces as the traffic was delivered locally (see Fig. 2.2).
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Figure 2.2: A D2D scenario.
2.3.3 Tactile Internet
The Tactile Internet will be the next evolution of the Internet of Things (IoT), encompassing human-to-machine and machine-to-machine interaction. It will enable real-time interactive systems with a raft of industrial, societal and busi- ness use cases. It will add a new dimension to human-to-machine interaction by enabling tactile and haptic sensations, and at the same time revolutionise the interaction of machines.
In order for technical systems to match human interaction with their envi- ronment, they must meet the speed of our natural reaction times. As such, 1ms end-to-end latency is necessary for Tactile Internet applications. The underly- ing network must also be ultra reliable as many critical tasks will be executed remotely and it must rely on cheap edge infrastructure in order to enable scale. It will therefore need 5G as the underlying network infrastructure.
It is also known as Ultra-Reliable Low Latency Communications (URLLC).
2.3.4 Industrial Internet of Things (IIoT)
It is similar to IoT but the focus is on the industrial applications which require ultra low latency and high reliability.
2.3.5 Internet of Skills
It is a new topic and will combine many concepts. Please have a look at this video u for more information.
2.4 Reading List
Read Chapter 5.1, 5.2, and 5.3 from From Machine-to-Machine to the Internet of Things.
D2D
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Read the following white papers on IoT from Ericson https://www.ericsson. com/res/docs/whitepapers/wp_iot.pdf.
Mission Critical IoT Communication in 5G https://www.researchgate. net/publication/288933722_Mission_Critical_IoT_Communication_in_5G.
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