Reprogramming Foundational Large Language Models(LLMs) for Enterprise Adoption for Spatio-Temporal Forecasting Applications: Unveiling a New Era in Copilot-Guided Cross-Modal Time Series Representation Learning
Sakhinana Sagar Srinivas, Chidaksh Ravuru, Geethan Sannidhi, Venkataramana Runkana
TL;DR
The paper tackles the challenge of accurate MTSF in enterprise settings by reprogramming foundational LLMs for time-series tasks. It introduces LLM-TS Net, a cross-modal framework that combines on-premise, fine-tuned open-source LLMs with traditional time-series encoders, dynamic prompting, and a Grouped-query Multi-head Attention (GQ-MHA) backbone to model intra- and inter-series dependencies. Key innovations include LoRA-AMR for memory-efficient fine-tuning on consumer hardware, a dynamic prompt pool with retrieval-based adaptation, and cross-modal integration of textual trend descriptions with time-series embeddings, enabling uncertainty estimation via a Gaussian likelihood (w/Unc-LLM-TS Net). Empirical results on PeMS and METR datasets show significant improvements over baselines in MAE, RMSE, and MAPE across multiple horizons, with robust performance under missing data and clear evidence that each component (LLM processing, dynamic prompting, intra-/inter-series modeling, and CMA) contributes meaningfully to predictive accuracy. The work demonstrates a practical, privacy-preserving path to enterprise-grade spatio-temporal forecasting through a memory-efficient, cross-domain, transformer-based architecture that leverages both textual descriptions and numerical patterns for robust forecasting and uncertainty quantification.
Abstract
Spatio-temporal forecasting plays a crucial role in various sectors such as transportation systems, logistics, and supply chain management. However, existing methods are limited by their ability to handle large, complex datasets. To overcome this limitation, we introduce a hybrid approach that combines the strengths of open-source large and small-scale language models (LLMs and LMs) with traditional forecasting methods. We augment traditional methods with dynamic prompting and a grouped-query, multi-head attention mechanism to more effectively capture both intra-series and inter-series dependencies in evolving nonlinear time series data. In addition, we facilitate on-premises customization by fine-tuning smaller open-source LMs for time series trend analysis utilizing descriptions generated by open-source large LMs on consumer-grade hardware using Low-Rank Adaptation with Activation Memory Reduction (LoRA-AMR) technique to reduce computational overhead and activation storage memory demands while preserving inference latency. We combine language model processing for time series trend analysis with traditional time series representation learning method for cross-modal integration, achieving robust and accurate forecasts. The framework effectiveness is demonstrated through extensive experiments on various real-world datasets, outperforming existing methods by significant margins in terms of forecast accuracy.
