IoT Interview Questions and Answers

The Internet of Things refers to the ever-developing network of bodily objects that feature an IP address for net connectivity, and the communiqué that occurs among these gadgets or objects and different Internet-enabled devices and systems.

The IoT is not separate from the Internet, but rather, a potentially huge extension and expansion of it. The things that form the basis of the IoT are objects. They could be virtually anything Streetlights, thermostats, electric meters, fitness trackers, factory equipment, automobiles, unmanned aircraft systems (UASs or drones), or even cows or sheep in a field. What makes an object part of the IoT is embedded or attached computer chips or similar components that give the object both a unique identifier and Internet connectivity. Objects with such components are often called “smart “such as smart meters and smart cars.

Internet connectivity allows a smart object to communicate with computers and with other smart objects. Connections of smart objects to the Internet can be wired, such as through Ethernet cables, or wireless, such as via a Wi-Fi or cellular network.

To enable precise communications, each IoT object must be uniquely identifiable. That is accomplished through an Internet Protocol (IP) address, a number assigned to each Internet-connected device, whether a desktop computer, a mobile phone, a printer, or an IoT object. Those IP addresses ensure that the device or object sending or receiving information is correctly identified.

IIOT stands for Industrial Internet of Things. This is very different when compared to the Internet of things application. When it comes to Industrial Internet of Things, they use heavy or critical machines something like the hardware used in aerospace and in defence where these devices are connected over a network and any failure of these devices will cause a life-threatening situation. Well, when it comes to the internet of things it is just done at a small scale levels where there is no need to worry about life-threatening situations because it is more catered towards the process execution and enhancement.

The IoT has many applications in the health care field, in both health monitoring and treatment, including telemedicine and telehealth. Applications may involve the use of medical technology and the Internet to provide long-distance health care and education. Medical devices, which can be wearable or nonwearable, or even implantable, injectable, or ingestible, can permit remote tracking of a patient’s vital signs, chronic conditions, or other indicators of health and wellness.36 Wireless medical devices may be used not only in hospital settings but also in remote monitoring and care, freeing patients from sustained or recurring hospital visits. Some experts have stated that advances in healthcare IoT applications will be important for providing affordable, quality care to the aging U.S. population.

People: People will continue to connect through devices, like smart phones, PCs and tablets, as well as through social networks, such as Facebook and LinkedIn. As the Internet of Everything emerges, the interaction of people on the Internet will evolve. For example, it may become common to wear sensors on our skin or in our clothes that collect and transmit data to healthcare providers. Some analysts even suggest that people may become individual nodes that produce a constant stream of static data.

Process: This includes evolving technology, business, organizational and other processes that will be needed in order to manage and, to a large extent, automate the explosive growth in connections and the resultant accumulation, analysis and communication of data that will be inevitable in the Internet of Everything. Processes will also play an important role in how each of these entities People, data, and things interact with each other within the Internet of Everything to deliver societal benefits and economic value.

Things: This element includes many physical items like sensors, meters, actuators, and other types of devices that can be attached to any object, that are or will be capable of connecting to the network and sharing information. These things will sense and deliver more data, respond to control inputs, and provide more information to help people and machines make decisions. Examples of things in the Internet of Everything include smart meters that communicate energy consumption, assembly line robots that automate factory floor operations, and smart transportation systems that adapt to traffic conditions.

Data: Today, devices typically gather data and stream it over the Internet to a central source, where it is analyzed and processed. Such data is expected to surpass today’s largest social media data set by another order of magnitude. Much of this data has very transient value. In fact, its value vanishes almost as quickly as it is created. As a result, not all generated data can be or should be stored. As the capabilities of things connected to the Internet continue to advance, they will become more intelligent and overcome the limits of traditional batch-oriented data analysis by combining data into more useful information. Rather than just reporting raw data, connected things will soon send higher-level information and insights back to machines, computers, and people in real time for further evaluation and decision making. The intelligent network touches everything and is the only place where it’s possible to build the scalable intelligence required to meet and utilize this new wave of “data in motion”. This transformation made possible by the emergence of the Internet of Everything is important because it will enable faster, more intelligent decision making by people and machines, as well as more effective control over our environment.

Human beings: People will continue to attach through gadgets, like smart phones, computers, and drugs, in addition to social networks, which includes FB and LinkedIn.

Procedure: This includes evolving era, business, organizational and different tactics in order to be wished in an effort to control and, to a massive extent, automate the explosive growth in connections and the resultant accumulation, analysis and conversation of information with a view to be inevitable inside the internet of the entirety.

Things: It consists of many physical objects like sensors, meters, actuators, and other styles of gadgets that can be connected to any item, that are or can be capable of connecting to the community and sharing statistics. These items will sense and supply more facts, respond to manipulate inputs, and provide more statistics to assist human beings and machines make choices.

Information: Today, devices commonly accumulate statistics and circulate it over the internet to a valuable source, in which it is analyzed and processed. Such statistics is predicted to surpass today’s biggest social media data set by means of every other order of importance.

The Internet of Everything (IoE)  “is bringing together people, process, data, and things to make networked connections more relevant and valuable than ever before-turning information into actions that create new capabilities, richer experiences, and unprecedented economic opportunity for businesses, individuals, and countries.”, (Cisco, 2013) .

In simple terms: IoE is the intelligent connection of people, process, data and things. The Internet of Everything (IoE) describes a world where billions of objects have sensors to detect measure and assess their status; all connected over public or private networks using standard and proprietary protocols.

The Generic Attribute Profile (GATT) establishes in detail how to exchange all profile and user data over a BLE connection. In contrast with GAP , which defines the low-level interactions with devices, GATT deals only with actual data transfer procedures and formats.GATT uses the Attribute Protocol as its transport protocol to exchange data between devices. This data is organized hierarchically in sections called services, which group conceptually related pieces of user data called characteristics.

Bluetooth Low Energy (BLE) is a low power wireless technology used for connecting devices with each other. BLE operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band, and is targeted towards applications that need to consume less power and may need to run on batteries for longer periods of time—months, and even years.

GAP stands for Generic Access Profile. It provides a framework that defines how BLE devices interact with each other.

Here, some of the most IoT companies are

• Amazon
• AT&T
• IBM
• Dell
• ARM
• Bosch
• Cisco
• Microsoft
• Oracle
• Qualcomm
• samsung
• Ingenu
• R-style Lab
• HQSoftware
• Ayla
• Fujistu
• GE
• IBE
• Intel
• Hitachi
• Huawei
• Nexiot

Generally speaking, M2M could be considered a subset of IoT. M2M is like a line connecting 2 points, and IoT is like a network, a system composed of lots of M2M and triggering lots of interactions/activities.

Giving a simple definition to M2M which is transferring data from one machine to another one. It’s been used everywhere in our daily life. For example, entrance security. Just like using your employee card to unlock a door. When the security detector receives the ID from the employee card and then unlocks the door once the ID is approved. This is called M2M.

In this case, what IoT can offer as mentioned, IoT is a network, is a system composed of lots of M2M and algorithms. When the system knows you are the person entering the office, it can turn on the light and the air conditioner of your partition, even it can adjust the most comfortable light level and temperature that you like the most from time to time after learning your behaviour for a period of time. The system can get all the data from all the sensors and machines to know, for example, who and when enters the office, how much electricity you have consumed, what the environment makes you feel most comfortable, and other applications.

IoT will make the facilities and things smarter and make people’s life more convenient. Not only machine to machine, but also human to machine, machine to human, and so on.

A potential barrier to the development of IoT is the technical limitations of the version of the Internet Protocol (IP) that is used most widely. IP is the set of rules that computers use to send and receive information via the Internet, including the unique address that each connected device or object must have to communicate. Version 4 (IPv4) is currently in widest use. It can accommodate about four billion addresses, and it is close to saturation, with few new addresses available in many parts of the world.

Some observers predict that Internet traffic will grow faster for IoT objects than any other kind of device over the next five years, with more than 25 billion IoT objects in use by 2020,76 and perhaps 50 billion devices altogether. IPv4 appears unlikely to meet that growing demand, even with the use of workarounds such as methods for sharing IP addresses.

Version 6 (IPv6) allows for a huge increase in the number IP addresses. With IPv4, the maximum number of unique addresses, 4.2 billion, is not enough to provide even one address for each of the 7.3 billion people on Earth. IPv6, in contrast, will accommodate over 1038 addresses  More than a trillion trillion per person.

It is highly likely that to accommodate the anticipated growth in the numbers of Internet-connected objects, IPv6 will have to be implemented broadly. It has been available since 1999 but was not formally launched until 2012. In most countries, fewer than 10% of IP addresses were in IPv6 as of September 2015. Adoption is highest in some European countries and in the United States, where adoption has doubled in the past year to about 20%.

Globally, adoption has doubled annually since 2011, to about 7% of addresses in mid-2015. While growth in adoption is expected to continue, it is not yet clear whether the rate of growth will be sufficient to accommodate the expected growth in the IoT. That will depend on a number of factors, including replacement of some older systems and applications that cannot handle IPv6 addresses, resolution of security issues associated with the transition, and availability of sufficient resources for deployment.

Efforts to transition federal systems to IPv6 began more than a decade ago. According to estimates by NIST, adoption for public-facing services has been much greater within the federal government than within industry or academia. However, adoption varies substantially among agencies, and some data suggest that federal adoption plateaued in 2012. Data were not available for this report on domains that are not public-facing, and it is not clear whether adoption of IPv6 by federal agencies will affect their deployment of IoT applications.

Many times, data from a single sensor is not useful in monitoring large areas and complex activities. Different sensor nodes need to interact with each other wirelessly. The disadvantage of non-IP technologies such as RFID, NFC, and Bluetooth is that their range is very small. So, they cannot be used in many applications, where a large area needs to be monitored through many sensor nodes deployed in diverse locations. A wireless sensor network (WSN) consists of tens to thousands of sensor nodes connected using wireless technologies. They collect data about the environment and communicate it to gateway devices that relay the information to the cloud over the Internet. The communication between nodes in a WSN may be direct or multihop. The sensor nodes are of a constrained nature, but gateway nodes have sufficient power and processing resources. The popular network topologies used in a WSN are a star, a mesh, and a hybrid network. Most of the communication in WSN is based on the IEEE 802.15.4 standard. There are clearly a lot of protocols that can be used in IoT scenarios. Let us discuss the design of a typical IoT network protocol stack with the most popular alternatives.

The Network routing layer handles the transfer the packets from source to destination.

RPL: Routing Protocol for Low-Power and Lossy Networks (RPL) is the distance-vector protocol that can support a variety of data link protocols. It builds a Destination Oriented Directed Acyclic Graph (DODAG) that has only one route from each leaf node to the root in which all the traffic from the node will be routed to.

CORPL: An extension of RPL is CORPL, or cognitive RPL, which is designed for cognitive networks and uses DODAG topology generation but with two new modifications to RPL. CORPL utilizes opportunistic forwarding to forward the packet by choosing multiple forwarders (forwarder set) and coordinates between the nodes to choose the best next hop to forward the packet to.

CARP: Channel-Aware Routing Protocol (CARP) is a distributed routing protocol designed for underwater communication. It can be used for IoT due to its lightweight packets. It considers link quality, which is computed based on historical successful data transmission gathered from neighboring sensors, to select the forwarding nodes.

ID: we need a unique method of object identification. An ID can be assigned to an object based on traditional parameters such as the MAC ID, IPv6 ID, a universal product code, or some other custom method.

Metainformation: along with an ID, we need some meta information about the device that describes its form and operation. This is required to establish appropriate relationships with the device and also appropriately place it in the universe of IoT devices.

Security controls: this is similar to “friend list” settings on Facebook. An owner of a device might place restrictions on the kinds of devices that can connect to it. These are typically referred to as owner controls.

Service discovery: such kind of a system is like a service cloud, where we need to have dedicated directories that store details of devices providing certain kinds of services. It becomes very important to keep these directories up to date such that devices can learn about other devices.

Relationship management: this module manages relationships with other devices. It also stores the types of devices that a given device should try to connect with based on the type of services provided. For example, it makes sense for a light controller to make a relationship with a light sensor.

Service composition: this module takes the social IoT model to a new level. The ultimate goal of having such a system is to provide better integrated services to users. For example, if a person has a power sensor with her air conditioner and this device establishes a relationship with an analytics engine, then it is possible for the ensemble to yield a lot of data about the usage patterns of the air conditioner. If the social model is more expansive, and there are many more devices, then it is possible to compare the data with the usage patterns of other users and come up with even more meaningful data. For example, users can be told that they are the largest energy consumers in their community or among their Facebook friends.