Network Optimization in Dynamic Systems: Fast Adaptation via Zero-Shot Lagrangian Update
I-Hong Hou
TL;DR
The paper tackles dynamic network utility optimization where abrupt changes in capacity, composition, service requirements, or channel conditions disrupt traditional stationary NUM methods. It develops zero-shot updates for the optimal Lagrange multipliers by deriving first-order (Taylor) approximations via complementary slackness, enabling fast reinitialization of dual variables for two canonical problems: Primal1 (distributed rate control) and Primal2 (drift-plus-penalty with service guarantees). The proposed approach sneakers in zero-shot estimates to bootstrap existing online learning algorithms, yielding substantial improvements in transitory performance and often near-optimal outcomes without extra iterations, validated by simulations across multiple change scenarios. This work provides a practical framework to maintain high utility, reduce operational costs, and limit constraint violations in dynamic wireless and data-processing networks.
Abstract
This paper addresses network optimization in dynamic systems, where factors such as user composition, service requirements, system capacity, and channel conditions can change abruptly and unpredictably. Unlike existing studies that focus primarily on optimizing long-term performance in steady states, we develop online learning algorithms that enable rapid adaptation to sudden changes. Recognizing that many current network optimization algorithms rely on dual methods to iteratively learn optimal Lagrange multipliers, we propose zero-shot updates for these multipliers using only information available at the time of abrupt changes. By combining Taylor series analysis with complementary slackness conditions, we theoretically derive zero-shot updates applicable to various abrupt changes in two distinct network optimization problems. These updates can be integrated with existing algorithms to significantly improve performance during transitory phases in terms of total utility, operational cost, and constraint violations. Simulation results demonstrate that our zero-shot updates substantially improve transitory performance, often achieving near-optimal outcomes without additional learning, even under severe system changes.
