SymED: Adaptive and Online Symbolic Representation of Data on the Edge

TL;DR

SymED is an innovative online, adaptive, and distributed symbolic data representation method designed for resource-constrained edge devices, enabling real-time data compression and analytics for IoT applications.

Contribution

It introduces SymED, the first online, adaptive, and distributed symbolic representation algorithm tailored for edge computing environments.

Findings

Achieves an average data compression rate of 9.5%.

Maintains low reconstruction error of 13.25 in DTW space.

Provides real-time processing with 42ms latency per symbol.

Abstract

The edge computing paradigm helps handle the Internet of Things (IoT) generated data in proximity to its source. Challenges occur in transferring, storing, and processing this rapidly growing amount of data on resource-constrained edge devices. Symbolic Representation (SR) algorithms are promising solutions to reduce the data size by converting actual raw data into symbols. Also, they allow data analytics (e.g., anomaly detection and trend prediction) directly on symbols, benefiting large classes of edge applications. However, existing SR algorithms are centralized in design and work offline with batch data, which is infeasible for real-time cases. We propose SymED - Symbolic Edge Data representation method, i.e., an online, adaptive, and distributed approach for symbolic representation of data on edge. SymED is based on the Adaptive Brownian Bridge-based Aggregation (ABBA), where we assume low-powered IoT devices do initial data compression (senders) and the more robust edge devices do the symbolic conversion (receivers). We evaluate SymED by measuring compression performance, reconstruction accuracy through Dynamic Time Warping (DTW) distance, and computational latency. The results show that SymED is able to (i) reduce the raw data with an average compression rate of 9.5%; (ii) keep a low reconstruction error of 13.25 in the DTW space; (iii) simultaneously provide real-time adaptability for online streaming IoT data at typical latencies of 42ms per symbol, reducing the overall network traffic.