Department of Artificial Intelligence, Kyungpook National University, Bukgu, Daegu 41566, Korea.
School of Computer Science and Engineering, Kyungpook National University, Bukgu, Daegu 41566, Korea.
Sensors (Basel). 2020 Nov 9;20(21):6391. doi: 10.3390/s20216391.
The Internet of Engineering Task (IETF) developed a lighter application protocol (Constrained Application Protocol (CoAP)) for the constrained IoT devices operating in lossy environments. Based on UDP, CoAP is a lightweight and efficient protocol compared to other IoT protocols such as HTTP, MQTT, etc. CoAP also provides reliable communication among nodes in wireless sensor networks in addition to features such as resource observation, resource discovery, congestion control, etc. These capabilities of CoAP have enabled the implementation of CoAP in various domains ranging from home automation to health management systems. The use of CoAP has highlighted its shortcomings over the time. To overcome shortcomings of CoAP, numerous enhancements have been made in basic CoAP architecture. This survey highlights the shortcomings of basic CoAP architecture and enhancements made in it throughout the time. Furthermore, existing challenges and issue in the current CoAP architecture are also discussed. Finally, some applications with CoAP implementation are mentioned in order to realize the viability of CoAP in real world use cases.
互联网工程任务组 (IETF) 为在有损环境中运行的受限物联网设备开发了一种更轻量级的应用协议 (受限应用协议 (CoAP))。基于 UDP，CoAP 与其他物联网协议（如 HTTP、MQTT 等）相比是一种轻量级且高效的协议。CoAP 还提供了无线传感器网络中节点之间的可靠通信，以及资源观察、资源发现、拥塞控制等功能。CoAP 的这些功能使得 CoAP 能够在从家庭自动化到健康管理系统等各种领域得到实现。随着时间的推移，CoAP 的使用也凸显了其缺点。为了克服 CoAP 的缺点，在基本的 CoAP 架构中进行了许多增强。本调查重点介绍了基本 CoAP 架构的缺点和随着时间的推移在其中进行的增强。此外，还讨论了当前 CoAP 架构中的现有挑战和问题。最后，提到了一些使用 CoAP 实现的应用程序，以实现 CoAP 在实际用例中的可行性。
