机载视频点播中的路由选择问题是有效保证点播服务用户体验的重要技术之一。该问题可抽象为一个受控离散时间排队系统,包括一个分发器与一些VoD服务器。该系统可用马尔科夫决策过程进行建模。由于马尔科夫决策过程存在状态空间爆炸问题,因此给出了一种基于贪心策略的启发式算法。该启发式算法较为简单,且可以在线执行。最后进行了大量仿真实验,说明启发式算法较为有效。
In this paper we investigate the request routing problem in the onboard Video-on-Demand (VoD) service, which is a key to provide good user experience. We model the system as a controlled queuing system including a dispatcher and several VoD servers. The system is formulated by Markov Decision Process (MDP). Since the MDP formulation suffers from the so-called "the curse of dimensionality" problem, we then develop a greedy heuristic approximate algorithm, which is simple and can be implemented online. The effectiveness of the approximation algorithm is evaluated through extensive simulations.