Semantic Filtering and Source Coding in Distributed Wireless Monitoring Systems
Pouya Agheli, Nikolaos Pappas, Marios Kountouris
TL;DR
This work develops a goal-oriented semantic framework for distributed wireless monitoring, where multiple sensors and monitors with heterogeneous goals exchange timely updates. It introduces a two-tier SoI model (microscopic meta-value and mesoscopic timeliness), two semantics-aware filtering schemes (fixed- and adaptive-length), and semantics-aware truncated error control, then derives optimal real-valued codeword lengths to maximize a weighted semantic utility. The results show that adaptive-length filtering and semantic encoding substantially improve timely, valuable updates, reducing channel blockage and retransmission overhead while preserving or enhancing semantic usefulness. Together, these contributions offer practical design insights for efficient, goal-driven status-update systems in multiuser wireless networks.
Abstract
The problem of goal-oriented semantic filtering and timely source coding in multiuser communication systems is considered here. We study a distributed monitoring system in which multiple information sources, each observing a physical process, provide status update packets to multiple monitors having heterogeneous goals. Two semantic filtering schemes are first proposed as a means to admit or drop arrival packets based on their goal-dependent importance, which is a function of the intrinsic and extrinsic attributes of information and the probability of occurrence of each realization. Admitted packets at each sensor are then encoded and transmitted over block-fading wireless channels so that served monitors can timely fulfill their goals. A truncated error control scheme is derived, which allows transmitters to drop or retransmit undelivered packets based on their significance. Then, we formulate the timely source encoding optimization problem and analytically derive the optimal codeword lengths assigned to the admitted packets which maximize a weighted sum of semantic utility functions for all pairs of communicating sensors and monitors. Our analytical and numerical results provide the optimal design parameters for different arrival rates and highlight the improvement in timely status update delivery using the proposed semantic filtering, source coding, and error control schemes.
