As Internet of Things (IoT) applications have gained increasing popularity, mechanisms to deal with congestion control owing to the large number of nodes have become a critical requirement. The Constrained Application Protocol (CoAP) is designed for low-power and lossy networks, using messages on the UDP, which relies on simple congestion control mechanisms. This method is suitable for IoT environments and can handle several nodes. In this study, we propose EnCoCo-RED, which is a new and enhanced congestion control mechanism for CoAP observe group communication. The mechanism provides buffer management, along with the adjustment of backoff algorithms according to the congestion levels in a network. To test its effectiveness, the mechanism was operated in two different scenarios. The experimental results demonstrate that EnCoCo-RED outperforms CoAP and CoCo-RED in terms of the settling time, throughput, packet loss, and response time.

随着物联网（IoT）应用程序的日益普及，由于节点数量众多，用于处理拥塞控制的机制已成为关键要求。受限应用协议（CoAP）是为低功耗和有损网络设计的，它使用基于简单拥塞控制机制的UDP上的消息。此方法适用于IoT环境，并且可以处理多个节点。在这项研究中，我们提出了EnCoCo-RED，这是一种用于CoAP观察组通信的新的增强型拥塞控制机制。该机制提供缓冲区管理，并根据网络中的拥塞级别调整退避算法。为了测试其有效性，该机制在两种不同的情况下运行。