Introduction Of IoT Networking (Part II)

IoT Network (Part II)

What is the requirement of IoT network?

Coverage:

• Wide Area: IoT networks should cover a broad geographic area, from urban centers to remote rural regions.
• Indoor Penetration: They should be able to penetrate buildings and other structures for reliable indoor coverage.

High Throughput:

• Efficient Data Transfer: IoT networks must be capable of handling large volumes of data generated by numerous connected devices.
• Scalability: They should be scalable to accommodate the increasing number of devices and data traffic.

Low Latency:

• Real-time Applications: IoT networks should provide minimal delay between data generation and processing. This is crucial for applications like remote monitoring, automation, and real-time control.

Ultra Reliability:

• Mission-Critical Applications: IoT networks need to be highly reliable, ensuring minimal downtime and consistent data transmission.
• Fault Tolerance: They should be able to recover from network failures and disruptions.

High Power Efficiency:

• Battery-Powered Devices: Many IoT devices operate on batteries, so the network must be designed to minimize power consumption.
• Energy-Efficient Protocols: Using energy-efficient communication protocols and techniques is essential.

What is MQTT?

MQTT stands for "Message Queue Telemetry Transport"

Introduced by IBM and standardized by Organization for the Advancement of Structured Information Standards (OASIS) in 2013.

Works on Publish/Subscribe framework on top of TCP/IP architecture.

Advantages:

Reliable, Lightweight, and cost-effective protocol.

What is MQTT QoS?

QoS of MQTT protocol is maintained for two transactions

First transaction:

Publishing Client : MQTT Server

Second transaction:

MQTT Server : Subscribing Client.

Client on each transaction sets the QoS level.

For the first transaction, publishing client sets the QoS level.

For second transaction, client subscriber sets the QoS level.

What is MQTT QoS level?

It supports 3 levels of QoS.

QoS 0:

Also known as “at most once” delivery.

Best effort and unacknowledged data service.

Publisher transmits the message one time to server and server transmits it once to subscriber.

No retry is performed.

QoS 1:

Also known as “at least once” delivery.

Message delivery between the publisher, server and then between server and subscribers occurs at least once.

Retry is performed until acknowledgement of message is recieved.

QoS 2:

Also known as “exactly once” delivery.

This QoS level is used when neither packet loss or duplication of message is allowed.

Retry is performed until the message is delivered exactly once.

What is CoAP?

Constrained Application Protocol.

CoAP was designed by IETF Constrained RESTful Environment.

(CoRE) working group to enable application with lightweight RESTful (HTTP) interface.

Works on Request/Response framework based on the UDP architecture, including Datagram Transport Layer Security (DTLS) secure transport protocol.

CoAP defines four types of messages

1. CON: Conformable

2. NON: Non-conformable

3. RST: Reset

4. ACK: Acknowledgement

For conformable type message, the recipient must explicitly either acknowledge or reject the message.

In case of non-conformable type message, the recipient send reset message if it can’t process the message.

Utilizes GET, PUT, OBSERVE, PUSH, and DELETE messages requests to retrieve, create, initiate, update, and delete subscription respectively.

Supports caching capabilities to improve the response time and reduce bandwidth consumption.

Uses IP multicast to support data requests sent to a group of devices.

Specialized for machine-to-machine (M2M) communication.

What is XMPP?

Extensible Messaging and Presence Protocol

Supports Publish/Subscribe messaging framework on top of TCP protocol.

The communication protocol is based on Extensive Markup Language (XML).

Uses Datagram Transport Layer Security (DTLS) secure transport protocol.

XMPP model is decentralized, no central server is required.

Advantages of XMPP:

Interoperability: Supports interoperability between heterogeneous networks.

Extensibility: Supports privacy lists, multi-user chat, and publish/subscribe chat status notifications.

Flexibility: Supports customized markup language defined by different organizations according to their needs.

What is AMQP?

Advance Message Queuing Protocol.

Optimized for financial applications.

Binary message-oriented protocol on top of TCP.

Supports Publish/Subscribe framework for both Point-to-point (P2P) and Multipoint communication.

Uses token-based mechanism for flow control.

Ensures no buffer overflow at the receiving end.

Message delivery guarantee services:

At least once: Guarantees message delivery but may do so multiple times.

At most once: Each message is delivered once or never.

Exactly once: No message drop and delivered once one.

What is IEEE 1888?

Energy-efficient network control protocol.

Defines a generalized data exchange protocol between network components over the IPv4/v6-based network.

Universal Resource Identifiers (URIs) based data identification.

Applications: Environmental monitoring, energy saving, and central management systems.

What is DDS-RTPS?

Distributed Data Service Real Time Publish and Subscribe.

Supports Publish/Subscribe framework and on top of UDP transport layer protocol.

Data-centric and binary protocol

Data is termed as “topics”.

The users/listeners may subscribe to their particular topic of interest.

A single topic may have multiple speakers of different priorities.

Supports enlisted QoS for data distribution such as:

1. Data persistence

2. Delivery deadline

3. Reliability

4. Data freshness

Applications: Military, Industrial, and healthcare monitoring.