We would like to welcome the readers to the second issue of the IEEE Communications Surveys and Tutorials in 2021. This issue includes 21 articles covering different aspects of communication networks. In particular, these articles survey and tutor various issues in “Wireless Communications,” “Vehicular and Sensor Communications,” “IoT and M2M,” “Network Security,” “Multimedia Communications,” “Internet Technologies,” “Network and Service Management,” and “Optical Communications.” A brief account for each of these articles is given below.

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社论：2021 年第二季度 IEEE 通信调查和教程


我们欢迎读者阅读 2021 年第二期 IEEE 通信调查和教程。本期包括 21 篇文章，涵盖通信网络的不同方面。特别是，这些文章调查并指导了“无线通信”、“车辆和传感器通信”、“物联网和 M2M”、“网络安全”、“多媒体通信”、“互联网技术”、“网络和服务管理”等领域的各种问题。 ”和“光通信”。下面对每篇文章进行简要说明。