| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 90 === With the explosive growth of the wireless mobile communication networks, the demand for multimedia applications is increasing rapidly. It is challenging to efficiently allocate limited networks resources in the wireless mobile networks to a variety of media services with different characteristics of QoS (Quality of Service) requirements. It is clear that in order to supporting real-time and non real-time services in wireless network, the scheme requires the development of a flexible, adaptable network resource management framework.
In [1], the proposed rate adaptation scheme takes an approach to fairly managing resources among competing users in response to dynamic variations of resource availability within cells. To efficiently cope with congestion, the scheme uses application specific quality satisfaction curves. However, if the handoff calls is unable to allocate resource to the call because other on-going calls take up too much resource, then the handoff call will be dropped. It is waste of resources and also an unsatisfactory experience for mobile users.
We propose a rate adaptation algorithm to allocate network resource for real-time and non real-time applications in which consists of resource borrowing and bandwidth adaptation. We assume that different call types require a different number of priority level that transfer different data types such as voice, data and video. In resource borrowing scheme, we temporarily borrow resource in which belonging to real-time applications or high priority resource that are not being used currently. Then we use bandwidth adaptation scheme to fairly manage resources. A key method of resource borrowing is to assign that borrowed resource from high priority level to lower priority sequentially. Of course, non real-time users information could suffer service degradation if real-time application users start using these resources. Basically, non real-time users information can temporarily store at a buffer under appropriate scheduling algorithm till the network has spare resource, unused by the real-time application.
We test our proposed dynamic priority-based resource borrowing scheme based on the rate adaptation algorithm compared with a non-dynamic priority-based resource borrowing allocation scheme [1], to support real-time and non real-time services. The results show that priority-based resource borrowing scheme has higher resource utilization and more flexible in allocating bandwidth while remaining low in blocking probability and dropping probability.
Keywords: wireless mobile networks, quality of service, real-time and non real-time, rate adaptation algorithm, dynamic priority-based resource allocation, blocking probability, dropping probability, resource borrowing, and bandwidth adaptation.
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