1)

a) Discuss the characteristics of IOT.

Ans-
The Internet of Things (IoT) is a system where everyday objects are connected to the
internet and can collect, send, and receive data. These objects can be sensors, devices,
vehicles, appliances, etc.

Below are the key characteristics of IoT:

i. Connectivity

IoT devices are connected to each other and to cloud services through the internet
(using Wi-Fi, Bluetooth, Zigbee, etc.).

This allows communication and data sharing between devices and systems.

ii. Intelligence

IoT devices are often combined with data analytics and machine learning to make
smart decisions based on data.

Example: Smart irrigation systems water plants only when needed.

iii. Sensing

IoT uses various sensors (like temperature, motion, humidity, etc.) to collect real-world
data.

These sensors help in monitoring and controlling systems remotely.

iv. Data

Data is the core of IoT. Devices continuously generate, transmit, and receive data,
which is then analyzed to take meaningful actions.

The more accurate the data, the smarter the system.

v. Real-time operation

IoT systems operate in real time. They detect changes and respond immediately.

Example: A fire alarm sensor detects smoke and instantly sends alerts.

vi. Scalability

IoT networks can grow easily. You can add more devices or sensors without disturbing
the existing system.

Useful in industries or smart cities where the number of connected devices increases
over time.

vii. Security and Privacy

Since IoT devices collect sensitive data, security and privacy are essential features.
Devices must be protected from hacking, and data must be encrypted.

Conclusion:

IoT combines connectivity, sensing, intelligence, and real-time processing to

create smart systems. These characteristics make IoT useful in areas like smart homes,
healthcare, agriculture, and industry.

b) Define M2M communication. Write about M2M communication

and architecture of M2M.
Ans-
Definition of M2M Communication

M2M (Machine-to-Machine) communication is the direct exchange of data between

two or more devices without human involvement.

Example: A smart electricity meter automatically sends energy usage data to the power
company.

Explanation of M2M Communication

 M2M is used when machines or devices need to share data with each other.

 It works using sensors, actuators, networks, and software.

 It helps in monitoring, controlling, and automating tasks.

Key Features of M2M Communication

 Automatic: Devices work without human help.

 Real-time data: Information is sent and received instantly.

 Remote access: Devices can be controlled from far away.

 Reliable communication: Data flows safely between machines.

Architecture of M2M Communication

M2M architecture has three main layers:

i. Device Layer (or Perception Layer)

 This includes sensors, actuators, and smart devices.

 Devices collect real-world data like temperature, pressure, motion, etc.

 ii. Network Layer

 Transfers data between devices and the server/cloud.

 Can use Wi-Fi, mobile networks (3G/4G/5G), Bluetooth, etc.

iii. Application Layer

 Provides services to users and businesses.

 Example: In smart homes, the mobile app that controls lights is in this layer.

Diagram of M2M Architecture

If you’re writing in an exam, draw a simple block diagram like this:

[ Devices & Sensors ] → [ Network (Wi-Fi/4G) ] → [ Server/Cloud ] → [ User

Applications ]

Conclusion

M2M communication is a key part of IoT. It allows machines to share data and perform
tasks automatically, improving efficiency in industries like healthcare, smart homes,
transportation, and more.

2)
a) What is the purpose of logical design in IOT systems? List the
key components typically considered in the logical design of an
IOT solution.
Ans-
Purpose of Logical Design in IoT Systems

The logical design of an IoT system is like a blueprint that shows how the system
works, without focusing on the actual hardware or physical devices.

Its main purpose is to:

 Show the data flow, communication, and functionality of the IoT system.

 Help designers and developers understand how different parts (like sensors,
cloud, apps) will connect and interact.

 Make sure that the system is organized, scalable, and efficient before starting
actual development.
Key Components of Logical Design in IoT

Here are the main components usually included:

i. Device (Sensors/Actuators)

 These are the "things" in IoT.

 They collect data (sensors) or perform actions (actuators).

ii. Communication

 Refers to how data travels between devices, network, and cloud.

 Can include Wi-Fi, Bluetooth, ZigBee, 4G/5G, etc.

iii. Data Processing

 Raw data collected by devices is processed to make it useful.

 Processing can happen on the device (edge computing) or on the cloud.

iv. Services

 Services perform specific tasks using the processed data.

 Example: An alert system that sends a message when temperature is too high.

v. Application

 This is the user-facing part of the system.

 Examples: Mobile apps, web dashboards, etc., where users monitor or control the
system.

Conclusion

Logical design helps in planning how an IoT system will work. It includes devices,
communication methods, data processing, services, and user applications. A good
logical design makes the system clear, efficient, and easy to build.

b) Summarize the challenges of a sensor node.

Ans-
Challenges of a Sensor Node in IoT

A sensor node is a small device that collects data from the environment, like
temperature, motion, light, etc. It plays a key role in IoT systems.

However, sensor nodes face many challenges:

i. Limited Power Supply

 Sensor nodes often run on batteries.

 They need to use power very carefully to last longer.

 Replacing or charging batteries is hard in remote areas.

ii. Limited Memory and Processing Power

 Sensor nodes have very small memory (RAM) and low processing capacity.

 They cannot perform heavy tasks or store large amounts of data.

iii. Data Transmission Limitations

 Sending data wirelessly uses a lot of power.

 Sensor nodes must send only necessary data to save energy.

 Communication range is also limited.

iv. Environmental Conditions

 Sensor nodes may be used outdoors or in harsh environments.

 Dust, heat, water, or vibrations can damage the sensor.

v. Security and Privacy Issues

 Sensor nodes can be easily attacked or hacked if not secured.

 Data can be stolen, or the node can be misused.

vi. Network Management

 In large networks, managing many sensor nodes is difficult.

 Handling failures, updates, or communication between nodes can be challenging.

vii. Cost Constraints

 Sensor nodes must be cheap because many of them are used in a network.

 Low cost often means limited features and quality.

Conclusion

Sensor nodes are important for IoT, but they face challenges like limited power,
memory, communication, and security. Designers must solve these problems to make
the system reliable and efficient.
3)
a) Discuss the fundamental difference between scaler sensors and
vector sensors.
Ans-
Difference Between Scalar Sensors and Vector Sensors

In IoT, sensors are used to measure physical quantities like temperature, speed,
direction, etc. Based on what they measure, sensors are classified into scalar and
vector sensors.

i. Scalar Sensors

 Scalar sensors measure quantities that have only magnitude (amount), not
direction.

 The data they give is a single value.

Examples:

 Temperature sensor → 25°C

 Pressure sensor → 1.2 bar

 Humidity sensor → 60%

Use Cases:

 Weather monitoring

 Smart agriculture

 Room temperature control

ii. Vector Sensors

 Vector sensors measure quantities that have both magnitude and direction.

 The data they give is usually a set of values (like x, y, z).

Examples:

 Accelerometer → measures acceleration in 3 directions (x, y, z)

 Gyroscope → measures angular rotation

 Magnetometer → detects magnetic field direction

Use Cases:

 Mobile phone orientation

 Vehicle motion tracking

 Drones and robotics

Key Differences Table

Feature Scalar Sensor Vector Sensor

Measures Only magnitude Magnitude + direction

Multiple values (usually 3

Output Single value
axes)

Example
Temperature sensor Accelerometer
Sensor

Data Type Simple Complex

Environment Motion tracking, orientation

Applications
monitoring sensing

Conclusion

The main difference is that scalar sensors give simple, one-value data (like
temperature), while vector sensors give more detailed, directional data (like
movement in 3D space). Both are important in different types of IoT applications.

b) Differentiate between electrical actuators and mechanical

actuators in terms of energy efficiency and control flexibility in
IOT deployments.
Ans-
Introduction

In IoT systems, actuators are devices that perform actions like moving a part, turning a
valve, or switching on a light. Actuators can be electrical or mechanical, and they
differ in energy efficiency and control flexibility.

i. Electrical Actuators

Definition:
Use electrical energy (like from a battery or power supply) to create motion or action.
Examples:
Electric motors, solenoids, servo motors.

Energy Efficiency:

 Generally more energy-efficient, especially for small or precise movements.

 Can be powered and controlled easily using low-voltage electricity.

Control Flexibility:

 Highly flexible and programmable.

 Can be controlled using microcontrollers, IoT platforms, or apps.

 Support precise control like speed, angle, and force.

ii. Mechanical Actuators

Definition:
Use mechanical energy like gears, springs, levers, or manual force to produce motion.

Examples:
Spring-loaded valves, pulley systems, hydraulic arms (partly mechanical).

Energy Efficiency:

 Often less efficient, especially if operated manually or with complex parts.

 Energy can be lost due to friction and mechanical wear.

Control Flexibility:

 Limited control compared to electrical actuators.

 Difficult to automate or adjust remotely in IoT setups.

 Often require manual control or basic triggers.

Comparison Table

Feature Electrical Actuator Mechanical Actuator

Energy Source Electrical energy Mechanical energy

Energy High (especially in small Lower (friction and wear

Efficiency systems) losses)

Control High (easy to program & Low (hard to control

Flexibility automate) remotely)

Common and easy to

Use in IoT Rare and less suited for IoT
integrate
 Conclusion

In IoT systems, electrical actuators are preferred due to better energy efficiency
and control flexibility. Mechanical actuators may still be used in specific cases but
are harder to automate and manage remotely.

4)
a) What is the basic working principle of RFID technology? How
does RFID enable wireless communication for data transfer?
Ans-
Basic Working Principle of RFID Technology

RFID stands for Radio Frequency Identification.

It is a wireless system used to identify and track objects using radio waves.

The main idea is:

An RFID reader sends out radio signals. When an RFID tag comes near the reader, it
responds by sending back data, such as an ID number.

Main Components of an RFID System

i. RFID Tag (Transponder):

 Attached to an object (like a product or card).

 Stores data like a unique ID.

 Can be active (with battery) or passive (no battery, powered by reader signal).

ii. RFID Reader (Interrogator):

 Sends radio waves to communicate with tags.

 Receives data from the tag and sends it to a computer system.

iii. Antenna:

 Both tag and reader have antennas to send and receive signals.

How RFID Enables Wireless Communication for Data Transfer

1. Reader sends signal:

The RFID reader sends out radio waves through its antenna.

2. Tag receives energy:

A passive tag absorbs this energy to power up its small chip.
3. Tag responds:
The tag sends its stored data (like ID or product info) back to the reader using radio
waves.

4. Reader processes data:

The reader receives the tag’s response and sends it to a backend system (like a
computer or cloud).

Example Use Cases

 Toll collection (FASTag)

 Library book tracking

 Retail inventory systems

 Employee ID cards

 Pet microchips

Conclusion

RFID works by using radio waves to wirelessly transfer data between a reader and a
tag. It allows fast, contactless communication and is widely used in tracking,
identification, and automation in IoT systems.

b) Describe how wireless networks became one of the enabling

technologies of IOT.
Ans-
Introduction

Wireless networks play a key role in the development and working of the Internet of
Things (IoT). They allow devices to communicate without physical cables, making
IoT systems more flexible and scalable.

How Wireless Networks Enable IoT

i. Easy Connectivity Without Wires

 Wireless networks connect devices like sensors, smartphones, and machines without
cables.

 This reduces installation cost and effort, especially in remote or moving

environments.
ii. Real-Time Communication

 IoT needs real-time data transfer.

 Wireless technologies like Wi-Fi, Bluetooth, ZigBee, 4G/5G provide fast and
reliable communication between devices.

iii. Scalability

 Wireless networks can support many devices at once.

 This is useful in smart homes, industries, and cities where hundreds or thousands
of devices may be connected.

iv. Mobility and Flexibility

 Wireless devices can move freely and still stay connected.

 Useful in applications like smart vehicles, wearable devices, and logistics tracking.

v. Wide Range of Technologies

Different wireless technologies are available for different needs:

 Wi-Fi: High speed, short range

 Bluetooth: Low power, very short range

 ZigBee: Low power, mesh networking

 LoRa, NB-IoT: Long range, low power

 4G/5G: High speed, long range, mobile access

Each one helps IoT work in a specific environment (home, factory, city, etc.).

vi. Support for Cloud and Internet Access

 Wireless networks let devices connect to the internet and cloud services.

 This helps in storing, analyzing, and sharing IoT data globally.

Conclusion

Wireless networks are a major enabler of IoT because they provide flexible, cost-
effective, and scalable communication between devices. Without wireless technology,
IoT systems would be limited and less practical.
5)
a) Explain the difference between NFC and other wireless
communication technologies used in IOT, such as Bluetooth and
Wi-Fi .
Ans-
Introduction

IoT systems use various wireless communication technologies. The most common ones
are NFC, Bluetooth, and Wi-Fi. Each has different range, speed, power usage, and
use cases.

i. NFC (Near Field Communication)

 Very short range: Works only when devices are very close (usually less than 4 cm).

 Low data speed: Transfers small amounts of data quickly.

 Low power: Uses very little energy, sometimes works without battery.

 Use cases: Contactless payments (e.g., Google Pay), identity cards, access control.

ii. Bluetooth

 Short range: Usually up to 10 meters (can go more with Bluetooth 5).

 Medium data speed: Good for sending audio or sensor data.

 Low power: Designed for low-power devices (especially Bluetooth Low Energy or
BLE).

 Use cases: Fitness trackers, wireless headphones, smart home devices.

iii. Wi-Fi
 Longer range: Up to 100 meters indoors.

 High data speed: Suitable for large data transfers like video streaming.

 High power usage: Not ideal for battery-powered devices.

 Use cases: Smart TVs, security cameras, laptops, IoT hubs.

Comparison Table

Feature NFC Bluetooth Wi-Fi

Range < 4 cm ~10–100 meters ~100 meters

Data
Low Medium High
Speed

Power
Very Low Low High
Usage

Setup Instant (touch- Few seconds (pairing Few seconds (Wi-Fi

Time based) needed) login)

Payments, access Wearables, smart Internet access, smart

Use Cases
cards gadgets homes

Conclusion

NFC, Bluetooth, and Wi-Fi all support wireless communication in IoT but serve different
purposes.

 NFC is best for short, secure, quick interactions.

 Bluetooth is great for low-power device connections.

 Wi-Fi is ideal for high-speed internet and long-range data needs.

b) What are the primary components of an MQTT-based
communication system in IOT?
Ans-
Introduction

MQTT stands for Message Queuing Telemetry Transport.

It is a lightweight communication protocol often used in IoT systems for sending
and receiving data over the internet.

Primary Components of an MQTT-Based Communication System

i. Publisher

 A device or application that sends data (messages).

 It could be a sensor that publishes temperature readings to the network.

 Example: A temperature sensor sending readings every 10 seconds.

ii. Subscriber

 A device or application that receives data.

 It listens to a specific "topic" and gets updates when new data is published.

 Example: A mobile app that receives and shows the temperature.

iii. Broker

 The central server that handles all communication between publishers and
subscribers.

 It receives messages from publishers and sends them to all matching

subscribers.

 It ensures secure, fast, and reliable message delivery.

 Example: Mosquitto (a popular MQTT broker).

 iv. Topic

 A label or channel used to organize messages.

 Publishers send messages to a topic; subscribers listen to topics.

 Example: Topic = home/kitchen/temperature

v. Messages

 The actual data sent by the publisher.

 Messages are sent in text or JSON format and are published under a topic.

 Example: {"temperature": 26.4}

vi. Client

 Any device (publisher or subscriber) that connects to the broker is called a client.

 IoT sensors, smartphones, or cloud services can all be MQTT clients.

6)
a) Describe the role of CoAP Acknowledgement (ACK) and Reset
(RST) messages in managing message delivery and error
handling.
Ans-
Introduction

CoAP (Constrained Application Protocol) is a lightweight protocol used in IoT

systems to send messages between devices over the internet or local networks.

To ensure reliable communication and error handling, CoAP uses special message
types like ACK and RST.

i. ACK (Acknowledgement) Message

 Purpose: Confirms that a message was received successfully.

 When a device sends a Confirmable (CON) message, it expects a reply.

 If the receiver gets the message properly, it sends back an ACK.

 Use Case:

o A sensor sends a reading to a server (CON message).

o The server replies with an ACK to say, "Message received."

 Helps in:

o Reliable message delivery

o Avoiding duplicates or message loss

ii. RST (Reset) Message

 Purpose: Tells the sender that the message was not understood or not
acceptable.

 Used when a device receives a message but:

o Cannot process it,

o Or the message was sent to the wrong destination.

 Use Case:

o If a server gets a message with an unknown format, it sends back RST.

 Helps in:

o Error detection and handling

o Informing sender that communication failed

Comparison Table
 ACK
Feature RST (Reset)
(Acknowledgement)

Message is received Message cannot be

Sent when
properly processed

Meaning "I got your message" "I can't understand this"

Handle errors or unknown

Use Case Confirm message delivery
msg

Message Response to Confirmable

Error response
Type msg

Conclusion

In CoAP, ACK messages ensure reliable delivery, while RST messages help in error
handling. Together, they make communication between IoT devices more robust and
dependable.

b) List and describe the main AMQP frame types used for
communication in IOT environments?
Ans-
Introduction

AMQP (Advanced Message Queuing Protocol) is a messaging protocol used in IoT

systems for reliable and secure communication between devices and servers.

In AMQP, communication happens through frames — small structured pieces of data

sent over the network.

Main AMQP Frame Types

i. Open Frame

 Purpose: To start a connection between a client and server.

 It contains basic details like host name and settings.

 Sent at the beginning of communication.

ii. Begin Frame

 Purpose: To start a session within a connection.

 A session is like a conversation inside the connection.

 Helps manage multiple channels in one connection.

iii. Attach Frame

 Purpose: To attach a link to the session.

 Links are used for sending or receiving messages.

 This frame sets up the direction of communication.

iv. Transfer Frame

 Purpose: To carry the actual message data (like sensor readings).

 This is the most important frame in AMQP for data transfer.

 It includes message content and delivery information.

v. Flow Frame

 Purpose: To manage data flow control.

 Helps avoid overloading the receiver by controlling how many messages can be sent.

 Like saying, “I can handle 10 more messages.”

vi. Disposition Frame

 Purpose: To acknowledge message delivery or report errors.

 It shows if a message was received successfully or rejected.

 Supports reliable communication.

vii. Detach Frame

 Purpose: To end a link between sender and receiver.

 Used when a device is done sending or receiving messages.

viii. End Frame

 Purpose: To end a session cleanly.

  Ensures the session is properly closed.

ix. Close Frame

 Purpose: To close the entire connection.

 Final frame in the communication process.

Conclusion

AMQP uses several frame types like Open, Transfer, Flow, and Close to manage
secure and reliable messaging in IoT systems. Each frame has a specific role in
starting, managing, transferring, and ending communication between devices.

7)
a) Describe the connectivity options available on a Raspberry Pi
board for interfacing with sensors, actuators and networks in
IOT setups.
Ans-
Introduction

The Raspberry Pi is a small, low-cost computer used in many IoT projects. It supports
different connectivity options to connect sensors, actuators, and networks.

i. GPIO (General Purpose Input/Output) Pins

 Used to connect digital sensors and actuators directly.

 You can read signals from sensors (like temperature sensors) or control devices (like
LEDs, buzzers, relays).

ii. I2C (Inter-Integrated Circuit)

 A protocol for connecting multiple sensors using only two wires (SDA and SCL).

 Used for devices like temperature sensors, accelerometers, and displays.

iii. SPI (Serial Peripheral Interface)

 High-speed communication for short distance between the Pi and devices.

 Used with sensors, memory chips, and displays.

iv. UART (Universal Asynchronous Receiver-Transmitter)

 Used for serial communication with devices like GPS modules, Bluetooth
modules, or Arduino boards.

 Communicates using Tx (Transmit) and Rx (Receive) pins.

v. USB Ports

 Can connect USB-based sensors, actuators, or wireless dongles (like Wi-Fi,

Zigbee, etc).

 Also used for keyboard, mouse, or camera modules.

vi. Ethernet Port (on some models)

 Provides wired internet connectivity.

 Useful in stable or secure network setups.

vii. Wi-Fi and Bluetooth (Onboard)

 Most modern Pi boards (like Pi 3 and 4) have built-in Wi-Fi and Bluetooth.

 Used for wireless communication with cloud, smartphones, or other IoT devices.

viii. HDMI Port (not for IoT sensors)

 Used to connect a display (not usually required for IoT-only projects, but helpful for
debugging).

Conclusion

Raspberry Pi supports many connectivity options like GPIO, I2C, SPI, UART, USB, Wi-
Fi, and Ethernet, making it a flexible and powerful platform for IoT projects
involving sensors, actuators, and network access.
b) Explain the smart home automation system in an IOT.
Ans-
Introduction

A smart home automation system is a key application of IoT (Internet of Things).

It connects home appliances and devices to the internet so they can be monitored,
controlled, and automated remotely using smartphones or computers.

Key Features of a Smart Home System

i. Remote Control

 You can control devices like lights, fans, AC, and cameras from anywhere using your
phone or voice assistant (like Alexa or Google Assistant).

ii. Automation

 Devices can work automatically using timers or sensors.

 Example: Lights turn on when you enter a room (motion sensor), or AC turns off when
room temperature is low.

iii. Monitoring and Alerts

 Get real-time updates about your home on your phone.

 Example: Security camera sends alert when someone is at the door.

iv. Energy Efficiency

 Smart devices help reduce energy use.

 Example: Smart lights turn off when not in use.

v. Safety and Security

 Smart locks, cameras, and alarms improve home security.

 You can monitor your home even while traveling.

Components of a Smart Home IoT System

  Sensors: Motion, temperature, gas, smoke, etc.

 Actuators: Motors, relays to control doors, fans, etc.

 Smart Devices: Bulbs, TVs, thermostats, switches.

 Connectivity: Wi-Fi, Bluetooth, ZigBee for communication.

 Smart Hub / Cloud: Controls the system and stores data.

 Mobile App / Voice Assistant: For user control.

Example Use Case

A smart home system turns on the porch light when it gets dark, locks the door at night
automatically, and sends an alert if motion is detected in the backyard.

Conclusion

A smart home system in IoT uses connected devices to provide comfort, security,
energy savings, and remote control, making daily life easier and more efficient.

8)Write a short note on :-

a) Components of IOT ecosystems
b) Sensor types
c) IOT challenges
d) Attacks in IOT system
e) Zigbee
Ans-
a) Components of IoT Ecosystem

The IoT ecosystem is made up of different parts that work together to collect data,
send it, process it, and take action.

Main Components:

 i. Sensors/Devices: Collect data like temperature, motion, light, etc.

 ii. Connectivity: Transfers data through Wi-Fi, Bluetooth, Zigbee, etc.

 iii. Data Processing: Analyzes the collected data (in cloud or locally).

 iv. Actuators: Devices that take action, like turning on a fan.

 v. User Interface: Apps or dashboards to control or view system activity.

 vi. Cloud/Edge Computing: Stores and processes data efficiently.

 vii. Security Layer: Protects data and devices from threats.

These components together help create smart systems like smart homes, smart cities,
and industrial IoT setups.

b) Sensor Types

Sensors are devices that detect and measure physical changes and send data to IoT
systems.

Common Sensor Types:

 i. Temperature Sensor: Measures heat or cold (e.g., in ACs or fridges).

 ii. Proximity Sensor: Detects nearby objects without contact (e.g., in phones).

 iii. Light Sensor (LDR): Measures light intensity (e.g., street lights).

 iv. Gas Sensor: Detects gases like CO₂, LPG (e.g., gas leakage systems).

 v. Motion Sensor (PIR): Senses movement (e.g., in security systems).

 vi. Humidity Sensor: Measures moisture in air (e.g., in weather stations).

 vii. Pressure Sensor: Detects air or water pressure (e.g., smart irrigation).

Sensors are essential in collecting real-world data in IoT systems.

c) IoT Challenges

IoT systems face several technical and practical challenges during implementation
and use.

Main Challenges:

 i. Security and Privacy: Protecting sensitive data and preventing hacks.

 ii. Power Management: IoT devices often run on batteries, so saving energy is
important.

 iii. Scalability: Handling a large number of connected devices.

 iv. Interoperability: Devices from different manufacturers must work together.

 v. Data Overload: Huge amount of data needs to be stored and processed

efficiently.

 vi. Network Reliability: Devices must stay connected without failures.

 vii. Cost and Maintenance: Building and maintaining IoT systems can be
expensive.

Solving these issues is key to making IoT more reliable and widely used.

d) Attacks in IoT System

IoT systems are often targets of cyberattacks due to weak security.

Common Attacks:

 i. DDoS Attack (Distributed Denial of Service): Overloads the system by sending

too many requests.

 ii. Man-in-the-Middle (MITM): Attacker intercepts data between two devices.

 iii. Eavesdropping: Hackers listen to communication to steal data.

 iv. Malware/Ransomware: Infects IoT devices and locks access until ransom is
paid.

 v. Physical Attacks: Directly tampering with hardware to damage or control it.

 vi. Replay Attack: Old communication is recorded and replayed to trick the system.

Proper encryption, authentication, and regular updates help prevent these attacks.

e) Zigbee

Zigbee is a low-power, wireless communication protocol used in IoT systems,

especially for home automation.
Key Features:

 i. Low Power Usage: Great for battery-powered devices like sensors.

 ii. Short Range: Usually up to 10–100 meters.

 iii. Mesh Network: Devices can talk to each other and extend coverage.

 iv. Secure: Uses 128-bit encryption for safety.

 v. Low Data Rate: Ideal for simple messages (not suitable for videos or large files).

 vi. Easy to Install: Often used in plug-and-play smart home products.

Use Cases:

 Smart lights, smart locks, sensors, remote controls, and alarm systems.

Zigbee is a popular choice for building reliable and energy-efficient smart home and
industrial systems.