Scheduling Disciplines in Cellular Data Services with Probabilistic Location Errors
| Autor: | Hao-Chih Cheng, 鄭浩志 |
|---|---|
| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 The coming of high-speed networking brings a juncture for new applications that need strict performance requirements. It is not difficult to prevision that provide a steady network for real-time transmission traffic to implement high requirements service is imperative. Thus, an integrated service network must serve all kinds of applications and be able to provide quality-of-service (QoS) guarantees to real-time session in the future. However, QoS guarantees are not easily implemented in wireless network because of the unique problems in wireless channels such as location-dependent. Subjecting an efficient and fair resource scheduler to wireless mobile networks is a challenging problem. There are several famous researches make a thorough study of this topic, such as CSDPS, IWFQ, CIF-Q and SBFA strategies. They can apply to the wireless network environment, which was suffered location-dependent error, but all of them content different request; some emphasize equity, some make high efficacy and some desire gracefully work. It is beyond doubt that each one of these researches has its advantage. So, no one could say which one was better than another. But, if we make a deeply study on them; it’s not hard to see that the schedulers mentioned above are not easy to be implemented in real environment except SBFA. Thus, the aim of this thesis is researching a discipline that could be realized easily. To provide cellular data services with differentiated QoS in a high data error-rate environment, a PWFQ (Probabilistic Weighted Fair Queueing) scheduling discipline, which extends WFQ scheme via probabilistic weight adjustments, was developed. PWFQ discipline compensated for the penalty derived from the location-dependent errors using the equivalent efficiency concept. The experimental results show that the system efficiency of PWFQ scheme was more stable than those of these existing schemes in real-time traffic flows. Though it is a pity that PWFQ discipline expense some transmission efficiency to archive it, it makes “fair transmission” much more practicable than existing ones. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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