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Weijia Zheng

Publications and source records attributed to Weijia Zheng.

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Enabling Safety-Critical Wireless Communications via Safe Reinforcement Learning

Ensuring strict safety guarantees is the paramount challenge for emerging 5G/6G wireless systems, particularly as they increasingly govern mission-critical applications ranging from autonomous UAV swarms to industrial automation. While deep reinforcement learning (DRL) offers a promising solution for complex resource allocation, standard algorithms frequently violate essential constraints, such as QoS mandates and power limits, posing unacceptable risks of system failure and regulatory non-compliance. We propose Safe-Deep Q-Learning, a novel algorithm that simultaneously addresses all three challenges: it handles mixed-integer nonconvex problems by approximating the Q-function, adapts to stochastic dynamics, and enforces dual-timescale constraints using integrated Lagrangian methods. Our framework features adaptive penalty scaling and constraint violation tracking, specifically tailored for wireless environments, and is designed to operate in both distributed and centralized architectural modes. We prove convergence to optimal constraint-satisfying policies under mild conditions and demonstrate robustness through dual variable stabilization. Validation on unmanned aerial vehicle (UAV) swarm control network and post-disaster emergency communications applications shows that Safe-Deep Q-Learning achieves stringent adherence to safety bounds with near-zero violation rates, significantly outperforming existing constrained RL baselines, establishing its effectiveness for safety-critical wireless deployments.

eess.SP

A Conditional-Probability-Distribution Model for Bandwidth Estimation with Application in Live Video Streaming

Experience of live video streaming can be improved if the video uploader has more accurate knowledge about the future available bandwidth. Because with such knowledge, one is able to know what sizes should he encode the frames to be in an ever-changing network. Researchers have developed some algorithms to predict throughputs in the literature, from where some are simple hence practical. However, limitation remains as most current bandwidth prediction methods are predicting a value, or a point estimate, of future bandwidth. Because in many practical scenarios, it is desirable to control the performance to some targets, e.g., video delivery rate over a given target percentage, which cannot be easily achieved via most current methods. In this work, we propose the use of probability distribution to model future bandwidth. Specifically, we model future bandwidth using past data transfer measurements and then derive a probability model for use in the application. This changes the selection of parameters in application into a probabilistic manner such that given target performance can be achieved in the long run. Inside our model, we use the conditional-probability method to correlate past and future bandwidth and hence further improve the estimating performance.

cs.MM

Empirical Conditional Method: A New Approach to Predict Throughput in TCP Mobile Data Network

Experience of live video streaming can be improved if future available bandwidth can be predicted more accurately at the video uploader side. Thus follows a natural question which is how to make predictions both easily and precisely in an ever-changing network. Researchers have developed many prediction algorithms in the literature, from where a simple algorithm, Arithmetic Mean (AM), stands out. Based on that, we are purposing a new method called Empirical Conditional Method (ECM) based on a Markov model, hoping to utilize more information in the past data to get a more accurate prediction without loss of practicality. Through simulations, we found that our ECM algorithm performs better than the commonly used AM one, in the sense of reducing the loss by about 10% compared with AM. Besides, ECM also has a higher utilization rate of available bandwidth, which means ECM can send more data out while not having a higher loss rate or delay, especially under a low FPS setting. ECM can be more helpful for those who have relatively limited networks to reach a more considerable balance between frame loss rate and video quality hence improving the quality of experience.

cs.NI