Modern Random Access-Based IoT Networks Design: From a Timeliness-Fidelity Perspective

Massive random access has gained attention as a potential solution for IoT networks due to the throughput comparable to orthogonal multiple access and significantly lower signaling overhead. In this article, we introduce the design of modern random access-based IoT networks, focusing on enhancing the timeliness and fidelity of the status update information. We first elaborate on the age of information (AoI) and the mean square error (MSE), which are used to assess information timeliness and information fidelity, respectively. Then, the multi-node sensing task model and the information quality objective function are established sequentially. In particular, the model involves the whole process of observation sampling, source coding, channel coding, random access, and information aggregation. The objective function is derived as a weighted sum of AoI and MSE. To achieve a tradeoff between information timeliness and information fidelity, we optimize key parameters such as quantization precision, the number of configured nodes, sampling frequency, and channel coding rate to minimize the objective function. Some future challenges are also presented.