| Summary: | 博士 === 國立交通大學 === 電機資訊國際學程 === 104 === 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 ¯nishes 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.
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