Internet of Things (IoT) and Infrastructure (D337)

Correct Answer B. Personal area network with low power consumption and low data rate

Explanation

Zigbee is a low-power, low-data-rate communication protocol typically used for short-range personal area networks (PANs). It is designed to connect devices like smart home appliances, sensors, and other IoT devices. Zigbee is energy-efficient, enabling long battery life for devices, and operates on a mesh network topology, where devices can communicate with one another to extend the range. Its main strengths are low power consumption, low data rates, and suitability for applications like home automation.

Why other options are wrong

A. High-power, high data rate, long-range network

This option is incorrect because Zigbee is specifically designed to be low-power and low-data-rate, not high-power or high-data-rate. Zigbee’s range is also relatively short compared to long-range communication technologies.

C. Wide area network with high bandwidth and extensive coverage

This is incorrect because Zigbee is not a wide area network (WAN) technology. It operates over short ranges (typically 10-100 meters) and is designed for low-bandwidth applications, unlike WANs that offer high bandwidth and long-range communication.

D. A cellular network designed for mobile communication

This is incorrect because Zigbee is not a cellular network and is not designed for mobile communication. It is a wireless protocol intended for short-range, low-power IoT devices, unlike cellular networks that are used for long-range communication with mobile phones and other devices.

Correct Answer D. photo-conductive device

Explanation

A Light Dependent Resistor (LDR) is a photo-conductive device. Its resistance changes in response to the intensity of light falling on it. As light increases, resistance decreases, allowing more current to pass through. This property is used in various light-sensing applications such as automatic lighting systems and brightness controls.

Why other options are wrong

A. photo-voltaic device

This is incorrect because photo-voltaic devices, like solar cells, generate electricity directly from sunlight. LDRs do not generate electricity; they change their resistance based on light.

B. photo-emissive device

This is incorrect because photo-emissive devices release electrons when exposed to light, as seen in photoelectric cells. LDRs do not emit electrons; instead, they change resistance in response to light.

C. photo-resistive device

Although this term might seem synonymous with LDRs, it is not the accurate classification. The correct technical term for an LDR is a photo-conductive device, which refers to a material’s conductivity changing with light—not just resistance in general.

Correct Answer C. Device-to-gateway communication model

Explanation

In the Device-to-Gateway communication model, IoT devices connect to a gateway, which acts as an intermediary between the devices and the cloud service. The gateway processes the data received from the IoT devices and forwards it to the cloud for further analysis and storage. This model is particularly useful when IoT devices are constrained by network limitations or when they cannot communicate directly with cloud services due to bandwidth or security concerns.

Why other options are wrong

A. Device-to-cloud communication model

This is incorrect because in this model, devices communicate directly with cloud services, bypassing the gateway. While this is a common IoT communication model, it does not involve the use of gateways.

B. Device-to-device communication model

This is incorrect because in this model, IoT devices communicate directly with each other, without involving cloud services or gateways. It is used for peer-to-peer communication but does not involve the cloud.

D. Back-end data-sharing communication model

This is incorrect because this model refers to the data sharing between servers or between the cloud and back-end systems, rather than communication between devices and cloud services through a gateway.

Correct Answer B. The concept began in the 1980s, with the first IP-based toaster showcased in 1990.

Explanation

The concept of smart connected devices started to gain traction in the 1980s, and the first notable example of such a device was an IP-based toaster presented at a conference in 1990. This toaster was one of the early demonstrations of how devices could be connected to the internet to enable new functionalities and automate tasks, marking the start of the IoT movement.

Why other options are wrong

A. The concept began in the 1990s with the introduction of smart refrigerators.

This option is incorrect because while the idea of connected devices started to gain attention in the 1990s, it was the IP-based toaster in 1990 that truly brought the concept to the forefront of technological discussions, not smart refrigerators.

C. The concept was first introduced in 2000 with the launch of smart home technology.

This is incorrect because the foundation of IoT was laid much earlier, and the idea of smart devices began gaining attention in the 1980s, not in the early 2000s. Smart home technology did become more popular in the 2000s, but the IoT concept itself predates this.

D. The concept originated in the early 2000s with the development of cloud computing.

This option is incorrect because although cloud computing has been integral to the growth and scalability of IoT, the concept of connected devices began long before the widespread development of cloud computing in the early 2000s. The 1980s is when the idea of connected devices first took off.

Correct Answer C. IETF is responsible for technical standards that make up the Internet protocol suite and W3C develops protocols and guidelines that ensure the long term growth of the web

Explanation

The Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C) are two distinct organizations with different focuses. The IETF is primarily responsible for the technical standards related to the Internet protocol suite, including protocols like TCP/IP, DNS, and HTTP. The IETF ensures that the foundational technologies that power the internet are standardized. The W3C, on the other hand, focuses on developing web standards, guidelines, and protocols to ensure the long-term growth and accessibility of the World Wide Web, such as HTML, CSS, and accessibility guidelines.

Why other options are wrong

A. IETF is responsible for technical standards that make up the Internet protocol suite and W3C is the same as the WWW

This option is misleading because it incorrectly states that W3C is the same as the WWW. While the W3C influences the development of the web, it is not the same as the World Wide Web itself.

B. There is no difference, they are the same organisation under different names

This is incorrect because the IETF and W3C are two separate organizations with different missions and areas of focus.

D. W3C is responsible for technical standards that make up the Internet protocol suite and IETF develops protocols and guidelines that ensure the long term growth of the web

This is incorrect because the IETF, not the W3C, is responsible for the Internet protocol suite, and the W3C focuses on web technologies and standards rather than the fundamental Internet protocols.

Correct Answer A. They would collaborate to develop and implement new standards.

Explanation

When new technologies emerge that require changes to internet protocols, the W3C (World Wide Web Consortium) and IETF (Internet Engineering Task Force) would likely collaborate to develop and implement new standards. Both organizations are focused on ensuring that the internet remains efficient, secure, and interoperable, and they work together to define protocols and guidelines for new technologies. The IETF typically focuses on the technical side of the protocols (such as networking), while the W3C focuses on the web standards (such as accessibility and content guidelines). Their joint efforts ensure that technological advancements integrate smoothly into the existing internet infrastructure.

Why other options are wrong

B. They would create a new organization to handle it

This is unlikely because both the W3C and IETF have well-established processes for handling new technologies and standards. They would typically collaborate within their existing structures.

C. They would leave it to private companies to decide

This is incorrect. W3C and IETF are standard-setting organizations that ensure interoperability and public interest, and they actively work to develop protocols rather than leaving it solely to private companies.

D. They would ignore the changes and maintain current protocols

This is incorrect. Both organizations are committed to evolving internet standards to meet the needs of emerging technologies. Ignoring changes would contradict their mission of maintaining the internet's growth and functionality.

Correct Answer C. UDP

Explanation

The Constrained Application Protocol (CoAP) is designed for use in simple devices that may have limited processing capabilities and low power. CoAP typically uses the User Datagram Protocol (UDP) because it is lightweight and does not require the overhead of a connection-oriented protocol like TCP. UDP is efficient for the limited data exchanges typical in IoT applications.

Why other options are wrong

A. TCP

This is incorrect because TCP is a connection-oriented protocol that involves more overhead due to error-checking and maintaining a connection. This makes it unsuitable for constrained devices that require minimal processing and efficient communication.

B. ICMP

This is incorrect because ICMP (Internet Control Message Protocol) is used primarily for error reporting and diagnostic purposes (e.g., ping). It is not a communication protocol for application data in IoT devices.

D. ARP

This is incorrect because ARP (Address Resolution Protocol) is used to map IP addresses to MAC addresses within a local network. It is not used for application-level communication in IoT devices.

Correct Answer A. end-to-end encryption

Explanation

End-to-end encryption is one of the most important security requirements for IoT systems because it ensures that data transmitted between devices is encrypted from the source to the destination. This prevents unauthorized access to sensitive data, even if the data is intercepted during transmission. End-to-end encryption ensures that only the intended recipient can decrypt and access the information, protecting the integrity and confidentiality of the data across the entire communication path.

Why other options are wrong

B. symmetric encryption

This is incorrect because while symmetric encryption is commonly used in IoT, it is just one method of encryption. Symmetric encryption involves using the same key for both encryption and decryption, but it does not necessarily guarantee end-to-end security unless implemented in a broader end-to-end encryption scheme.

C. mesh network

This is incorrect because a mesh network is a type of network topology, not a security measure. While mesh networks are often used in IoT for robust communication, security in IoT primarily relies on encryption methods, not network topologies.

D. RSA

This is incorrect because RSA is a specific asymmetric encryption algorithm used for securing communications, but it is not the most suitable or comprehensive solution for securing the entire IoT communication process. End-to-end encryption can involve RSA or other encryption methods, but the broader concept is more important than any single encryption technique.

Correct Answer B. Social, economic, technical

Explanation

The Internet of Things (IoT) has a broad impact across multiple areas, with social, economic, and technical being the primary domains. Socially, IoT can influence behavior and lifestyle, providing smarter living experiences. Economically, IoT can streamline industries, reduce costs, and create new revenue opportunities. Technically, IoT pushes forward the development of connectivity, data analysis, and cloud computing, enhancing how systems and devices interact.

Why other options are wrong

A. Cultural, environmental, technical

While IoT does influence cultural and environmental aspects, the most significant areas of impact are social, economic, and technical, which directly relate to how IoT systems function in society and economies.

C. Political, educational, environmental

Although IoT may have political and environmental effects, the key areas of influence in the context of IoT are social, economic, and technical, which are more directly impacted by the connectivity and functionality that IoT provides.

D. Social, legal, technical

Legal considerations are important, but the primary areas of impact are more centered around economic and technical aspects rather than the legal aspects, which are still evolving in response to IoT technologies.