标题: | 蜂巢式网路中利用历史资讯之频宽保留及存取控制法 A History based Adaptive Bandwidth Reservation and Admission Control Mechanism in QoS-Sensitive Cellular Networks |
作者: | 陈逸伦 Yi-Lun Chen 陈耀宗 Yaw-Chung Chen 资讯科学与工程研究所 |
关键字: | 蜂巢式网路;存取控制;资源保留;历史资讯;动态调整;cellular network;admission control;resource reservation;history;adjust adaptively |
公开日期: | 2002 |
摘要: | 在现今无线多媒体网路中,当使用者在基地台之间交递 (handoff) 时,系统如何提供连续性 (continuity) 的服务品质保证 (QoS guarantee),一直是个非常重要的项目。一般来说,通讯进行中被强制断线 (forced termination) 对无线网路使用者来说,较之于连线建立失败 (new-call blocking) 更加令使用者不悦。因此,如何避免使用者在交递过程中失败是一个重大且值得深入研究的课题。 在这篇论文之中,我们提供了一个网路存取控制的架构,并且动态地保留频宽给由相邻基地台交递而来的使用者,藉此控制交递失败的机率 (Handoff drop-ping probability),使其低于我们所预先设定的数值。而频宽保留的策略,则是基于各个基地台所搜集到的系统历史资讯,依照过去使用者的行为来判断及决定频宽保留的大小。此外,我们也提出了一个可以随时调整的机制,使得交递失败率跟系统使用率 (System utilization)、连线建立失败率 (New-call blocking probability) 能够随时达到一个良好的平衡。模拟的结果则显示我们所提出的系统的确能够有效地控制交递失败率,并且达到良好的系统使用率。在复杂度及储存资料量方面的比较,也说明了我们的方法比现有机制更加精简以及有效。 Nowadays, how to provide continuity and keep Quality-of-Service (QoS) guarantee during the handoff period of a mobile host is an crucial issue multimedia wireless communications. In general, a forced termination is very objectionable for users and considered as more serious than a new-call blocking. Therefore, to avoid handoff dropping is an important topic that needs further investigation. In this thesis, we propose call admission control schemes that adaptively reserve resource for handoff calls in order to keep the handoff dropping probability below a certain level. In these methods, bandwidth reservation is based on the collected history record in each base station and the mechanism is dynamically adjustable. Simulation results show the satisfactory data in new-call blocking probability, handoff-call dropping probability, system utilization and complexity. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT910392013 http://hdl.handle.net/11536/70083 |
显示于类别: | Thesis |