IoT Protocols - A Deeper Look

Protocols

Protocols are set of rules used to define communication and transmission of data between devices. They are used as a guideline to encrypt, decrypt or secure the flow of information. We have different modes through which data passes from one device to the other. They include

• WiFi

• Bluetooth

• Cellular

• Zigbee

• Matter

• Zwave

Basically we can split data protocols into two divisions. They are

• IoT Data Protocol: They are used in Application and Presentation layers

• Network Protocol: Used in Data Link Layer and Physical layers.

Lets first look at the different versions of IoT Data Protocol. They are based according to their power consumption, security strength and transmission rate.

• XMPP ( Extensible Messaging Presence Protocol ): Is a free open source standard and used in messaging app like Skype, messenger etc. The same can be applied to IoT devices for machine to machine or client server communication. Here each device is given a unique id like an email address. Then it is added to the network node. Supports both structured and unstructured data.

• MQTT ( Message Queuing Telemetry Transport ): Lightweight and low power consumption. Uses a client subscriber messaging service. Works on top of TCP/IP protocol. However MQTT doesn't have a common standard. So they vary for different hardware vendors. IoT  devices now  being more unique than ever, this can lead to compatibility issues. Also there is no inbuilt security, which can increase cyber threats

• COAP ( Constrained Application Protocol ): Used in Application layer. Is centered around HTTP ( Hyper Text Transfer Protocol ). Though this standard has been widely used in the internet, for IoT devices they lead to very high power consumption and complexity. COAP has reduced both these drawbacks making it lightweight and user friendly. Targeted devices are low power micro controllers.

• AMQP ( Advanced Message Queuing Protocol): Used in server to server communication. Sets standard for receiving and queuing data, storing and end to end linkage. However the power consumption is high and the complexity of installation. Mainly used in banking sector.

• DDS ( Data Distribution Server): MQQT by nature. The mode of communication is client to server. They are not tied to any specific hardware or software platform. This means inter communication between  devices of separate vendors.

Now comes the Network Protocols. They include

• Light Weight M2M: Transfers data in the form of small packets. Usually synchronous in nature. Low power consumption allows for field applications. An example being a geological project where sensors are placed at remote locations and data need to be recorded in specific time intervals. 

• Cellular: Most reliable and widely used. They provide good bandwidth coverage and speed. 4G is mostly used which has now pivoted to 5G and 6G in the near future.

• WiFi:  Provides coverage up to 100 meters and link multiple devices. Operates at frequency from 2.4 GHz  to 5 GHz.

• ZigBee: Spans up to 100 meters. Provides inbuilt security and connects up to 100 nodes.

• Thread: Works on internet standards. Very low power consumption and self healing nodes. This means any node can act as a router if the other goes down. Supports up to 250 devices of which 32 can act as routers.

• Zwave: Uses wireless radio frequency from 800 to 900 MHz. This results in lesser interference compared to ZigBee (is in the WiFi range).

Final Note

Each protocol has its benefits and drawbacks. So the use case is based on the consumer's priorities be it security or data bandwidth or power output.