Hybrid Uplink Scheduling for Discontinuous Realtime Traffic
| Autor: | Ding-Yu Huang, 黃鼎御 |
|---|---|
| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Taking the advantage of silence suppression, the communication systems need not to allocate radio resources for the users in silence state. By doing so, the system capacity can be significantly improved. The main issue for the systems with discontinuous re- altime traffic is how to immediately allocate resources, while the users reactivate and transit from the silence state to active state. Traditionally, there are two typical band- width request (BR) methods: the unicast-polling and the multicast-polling methods. The unicast-polling BR method can guarantee the bandwidth request delay, but at the cost of much more resources allocated for bandwidth requests. The multicast-polling method has lower resource overhead needed for bandwidth requests, whereas cannot ensure the bandwidth request delay because of contention collisions. In this thesis, we propose the hybrid-multicast/unicast-polling method, which combines the multicast polling and unicast polling. In the proposed hybrid BR method, we can adopt longer period for the unicast-polling to lower resource overhead used for polling, and shorter period for the multicast-polling to reduce the bandwidth request delay. To compare the hybrid-polling, unicast-polling, multicast-polling methods, we develop analytical models to evaluate bandwidth request delay, delay variance, bandwidth request failure probability, and resource overhead for BR polling. On the top of analytical mod- els, we formulate the optimization problem to determine the period of polling, and resource units in a multicast-polling contention window, aiming to minimize the re- source overhead for BR polling, under the requirements of bandwidth request delay and bandwidth request failure probability. Numerical results show that the proposed hybrid-polling method achieves comparable resource overhead for bandwidth request as the multicast-polling method, with a guaranteed bandwidth request delay. We have also performed extensive simulations to verify the analytical models. The analytical models can provide important insights for network planning to ensure the bandwidth request delay and lower resource overhead for bandwidth request. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|