标题: 广义认知无线网路的资源管理
Resource Management for Generalized Cognitive Radio Networks
作者: 沙慕
王莅君
Samer Talat
Wang,Li-Chun
电机资讯国际学程
关键字: 认知无线网路;资源管理;M/G/1 排队模型;Cognitive Radio Network;Resource Management;Variable bandwidth;M/G/1 queuing model
公开日期: 2015
摘要: 感知无线电网路由高优先级的主用户和低优先级的次用户组成。当主用户不使用他们的许可频谱时,次用户可以暂时利用未使用的频谱。广义感知无线电系统应能运用所有可用频道之不同频宽,而当主用户打断时即应归还所借的通道。

当中断发生时,次用户需从不同频宽的通道中选择一个新的操作通道,或在相同的通道等待,直到主连接完成其传输。因此,一个次用户的连接在其传输过程中可能会执行多次切换或使用不同的路由。为了克服因主用户打断造成的潜在性能下降问题,可用资源管理技术来提高广义感知无线电网路之性能。在本论文中,我们探讨广义感知无线电网路中资源管理的三个议题。

第一个议题是不同频宽通道对频谱选择的影响。我们介绍了负载平衡频谱选择机制,用于具有各种频宽通道的感知无线电网路。此负载平衡频谱选择机制是基于延迟与频宽之乘积,从各频宽通道中选择合适的通道。

第二个议题是考虑多次频谱换手中断之影响。我们介绍了一个基于先占复原优先权 M / G / 1 排队理论的分析架构。基于先占复原优先权 M / G / 1 排队网路模型,我们可以评估多次换手与各种频宽通道对整个系统的时间的影响。

第三个议题是考虑多个中间路由节点对决定路由路径的影响。我们设计了一个决定有效路由的方法,以适应当主用户出现在节点现有的路线时需频繁建立新路由路径之需求。此路由决定是基于选择性路由机制的概念,并根据需要迅速选择具有最低端到端延迟之路径。


总结来说,本论文的主要贡献是从宏观视点并基于各种频宽通道和多次主用户打断,调查广义感知无线电网路之建模技术。我们所提出的分析框架可帮助分析感知无线电网路之性能,并在设计各种具有增强性能的资源管理技术时提供重要的洞见。
A cognitive radio (CR) network consists of the high-priority primary users and the low-priority secondary users. When the primary users do not use their licensed spectrum, the secondary users can temporarily utilize the unused spectrum. A generalized CR system shall be able to utilize all the available channels of various bandwidths, but shall return the borrowed channels whenever the active primary users interrupt. When the interruption occurs, the secondary connections need to select a new operational channel from
various bandwidth channels or wait at the same channel till the primary connection ˉnishes its transmission. Consequently, a secondary user connection may execute multiple handoffs or use different routing paths during its
transmission period. In order to overcome the potential performance degradation due to primary user interruptions, resource management techniques can be used to enhance generalized CR networks performance.

In this dissertation, we investigate resource management in generalized CR networks for three issues. The first issue is considering the effects of various bandwidth channels on spectrum decision. Thus, a load balancing spectrum decision scheme for CR networks with various bandwidth channel
is introduced. This load balancing spectrum decision scheme is based on the concept of the delay bandwidth (DB) product to select suitable channel from various bandwidth channels. The second issue is to consider the effect of multiple interruptions on spectrum handoffs. Hence, an analytical framework based on the preemptive resumption priority (PRP) M/G/1 queueing theory is introduced. Based on the PRP M/G/1 queueing network model, we can evaluate the effects of multiple handoffs and various bandwidth channels on
the overall transmission latency. The third issue is to consider the effects of multiple intermediate routing nodes on routing path decision. As a result, an effective routing decision design is introduced to adapt the frequent need
to establish a new route path as primary user appears in the nodes of the existing route. This routing decision is based on the concept of selective routing mechanism to select the minimum end-to-end delay route as quickly as needed.

To summarize, the main contribution of this report is to investigate the modelling techniques for generalized CR networks from a macroscopic view-point based on the various-bandwidth channels and multiple primary user interruptions. The proposed analytical framework can help analyze the performances of CR networks and provide important insights into the design of various resource management techniques with enhanced performance.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT079413823
http://hdl.handle.net/11536/139117
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