LEC 7 IOT Flashcards
(14 cards)
What is IoT?
A system where physical devices (sensors, actuators, embedded systems) communicate over various networks.
What are the pros and cons of internet protocols in IoT?
Pros : Popular and well tested, versatile for various applications
Cons: High power consumption, heavyweight communication protocol and limited IP addresses
What are the key layers of IoT architecture?
1.Smart Things Layer (Embedded systems) : bridges real and digital worlds and includes sensors, actuators and machines
2.Connectivity Layer – handles communication using wired (ethernet,rs485,ModBus) and wireless (NFC, WIFI, Bluetooth)
3. Data Storage & Processing Layer – Manages IoT-generated data in two stages:
Data accumulation (determining relevance)
Data abstraction (analyzing data for insights)
4. Application Layer (UI) – Where users interact with IoT data.
What is the role of gateways in IoT connectivity?
Provides a bridge between diff types of communication technologies.
Benefits of gateways
Pre-process data at the edge to improve response time
provides security by adding extra line of defense
improve energy efficiency
convert multiple IOT connections into a single protocol
what is IOT protocol
Protocol enables devices to talk to each other
Common IOT communication protocols
HTTP – Used for web apps and APIs
MQTT – Lightweight messaging for IoT
AMQP – Secure messaging between cloud services
DDS – Real-time machine-to-machine communication
What is MQTT?
Message Queuing Telemetry Transport (MQTT) is a lightweight protocol for IoT communications. Designed for low bandwidth, high-latency networks.
Uses a broker-based model:
Publisher sends messages on a topic.
Subscriber receives messages from a topic.
Broker manages message flow.
What are the MQTT QoS (Quality of Service) levels?
QoS-0: At most once – Best effort delivery.
QoS-1: At least once – Ensures delivery but may duplicate messages.
QoS-2: Exactly once – Guarantees message delivery without duplication.
Advantages of MQTT
Lightweight and efficient
supports intermittent connections
Fast message delivery
What consists of the architecture in MQTT
Broker: manages message distribution
Client: Publish/subscribe to topics
Topics: define message categories
what does clean session and last will messages mean
Clean session ; broker does not rmb past connections
Last will: message is sent if device disconnects unexpectedly
How does MQTT compare to HTTP?
MQTT is asynchronous, while HTTP is synchronous.
MQTT is 93x faster than HTTP in some networks. (3G network)
MQTT uses 10x less bandwidth than HTTP.
What are real-world applications of MQTT?
Smart home automation
Industrial monitoring
Real-time IoT applications
