1. 受限应用协议(COAP)：
受限应用程序协议是基于客户端服务器的协议。通过该协议，COAP 数据包可以在 COAP 服务器的命令下在不同的客户端节点之间共享。服务器负责根据其逻辑共享信息，但不必确认。这与支持状态传输模型的应用程序一起使用。
2.消息查询遥测传输(MQTT)：
消息查询遥测传输协议是一种基于通信的协议，用于物联网设备。该协议基于发布-订阅方法，其中客户端仅通过代理接收订阅主题的信息。 Broker 是一个中介，它在传递之前将消息分类为标签。
COAP和MQTT协议的区别：
| Basis of | COAP | MQTT |
|---|---|---|
| Abbreviation | Constrained Application Protocol | Message Query Telemetry Transport |
| Communication Type | It uses Request-Response model. | It uses Publish-Subscribe model |
| Messaging Mode | This uses both Asynchronous and Synchronous. | This uses only Asynchronous |
| Transport layer protocol | This mainly uses User Datagram protocol(UDP) | This mainly uses Transmission Control protocol(TCP) |
| Header size | It has 4 bytes sized header | It has 2 bytes sized header |
| RESTful based | Yes it uses REST principles | No it does not uses REST principles |
| Persistence support | It does not has such support | It supports and best used for live data communication |
| Message Labelling | It provides by adding labels to the messages. | It has no such feature. |
| Usability/Security | It is used in Utility area networks and has secured mechanism. | It is used in IoT applications and is secure |