Distributed and Dynamic Resource Management for Wireless Service Delivery to High-Speed Trains

With the fast development of high-speed railway (HSR), how to provide high-quality and cost-effective wireless services for HSR users has attracted increasing attention in recent years. A key issue is to design an efficient resource management scheme for wireless service delivery between the train and the ground. In this paper, we first provide an overview of the existing resource management schemes and some unsolved challenges are identified. To address these challenges, a cross-layer optimization framework is developed for facilitating the design and optimization of dynamic resource management. Then, the resource management problem is formulated as a stochastic optimization problem, which jointly considers the quality-of-service requirements and dynamic characteristics of HSR wireless communications. The stochastic network optimization theory is applied to transform the intractable stochastic optimization problem into a tractable deterministic optimization problem, which can be further decomposed into two separate subproblems: admission control and resource allocation. A fully distributed admission control scheme is proposed for the admission control subproblem, and a cooperative distributed resource allocation scheme is developed for the mixed-integer resource allocation subproblem with guaranteed global optimality. Finally, a distributed dynamic resource management algorithm is proposed to solve the original stochastic optimization problem with high reliability and robustness against central node failure. The performance of the proposed algorithm is analyzed theoretically and further validated by numerical simulations under realistic conditions for HSR wireless communications.