Real-Time Monitoring With Timing Side Information

Real-time monitoring plays a pivotal role in the Industrial Internet of Things (IIoT) with potential applications in factory automation, automated driving, and telesurgery, thereby attracting considerable recent attention in anticipation of the development of the sixth-generation (6G) of wireless networks. In this paper, we present a paradigm-shift data compression method that makes use of timing side information (TSI) obtained by observing two synchronized clocks at a remote sensor and a monitor. In particular, the TSI is found to allow the transmitter to send fewer bits consumed in characterizing the changing or holding time of a piecewise-constant stochastic process. We borrow the idea of source coding with side information to reveal the performance limits of both TSI-based lossless and lossy compression, and to develop practical low-complexity source coding schemes. To further reduce the implementation complexity and the hardware cost, we also present a real-time monitoring scheme where the sensor does not necessarily measure the state transition time. A statistical signal processing algorithm is adopted to estimate the changing time accurately. Our theoretical and numerical results show that the compression gain owing to the TSI is quite substantial, especially when the communication latency and the delay jitter are limited.