博士論文摘要
The promising development of wireless technologies has brought in an increasing demand of multimedia traffic. Since various types of traffic are inherently distinct in bandwidth requirements, delay sensitivities, and error tolerances, an adequate bandwidth allocation scheme is essential for the limited radio resource to fulfill different QoS (quality of service) requirements in mobile wireless networks. In this dissertation, we present a generalized channel preemption scheme (the GCPM) and a jamming-based medium access control with dynamic priority adjustment (the JMPDA) for the two different medium access models of a mobile wireless network, grant/request-based and contention-based, respectively.
In the proposed GCPM, a mobile call is identified by four parameters, call type, traffic class, channel requirement, and preemption ratio. To effectively reduce dropping probability, high-priority handoff calls are allowed to fully or partially preempt low-priority ongoing calls when the mobile network becomes congested. An analytical model with multi-dimensional Markov chains is introduced to simultaneously investigate the effect of full and partial preemptions on the performance of a mobile wireless network. On the other hand, the proposed JMDPA scheme prioritizes a mobile node with two priorities, local and global; both of the local and global priorities can be dynamically changed based on the outcome in every contention round. Thus, any possible starvation of low-priority traffic or any ineffective contention of high-priority traffic can be avoided. A multi-dimensional Markov model, together with the scalability analysis, is introduced to evaluate the performance of the proposed JMDPA. The analytical results provide very useful guidelines to tune the QoS parameters for supporting prioritized multimedia traffic. Keywords ：Multimedia Traffic, QoS, Handoff Calls, Channel Preemption, Jamming Noise, MAC, Markov Chains
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Publication List
Journal Papers:
1. T.-L. Sheu, Yang-Jing Wu, and Bo Li, “A generalized channel preemption model for multiclass traffic in mobile wireless networks,” to appear in IEEE Trans. on Vehicular Technology . (SCI)
2. T.-L. Sheu and Yang-Jing Wu, “A jamming-based medium access control with dynamic priority adjustment in wireless ad hoc networks,” to appear in IEE Proceedings–Communications . (SCI)
3.Yang-Jing Wu, P.-C. Hu, and T.-L. Sheu, “Service differentiations with dynamic jamming-length control in wireless ad hoc networks,” WSEAS Trans. on Communications , vol. 5, no. 8, pp. 1376-1383, August 2006. (EI)
4.
T.-L. Sheu and Yang-Jing Wu, “A preemptive channel allocation scheme for multimedia traffic in mobile wireless network,” Information Sciences , vol. 176, no. 3, pp. 217-236, Feb. 2006. (SCI)
5.
Yang-Jing Wu, J.-H. Chiu, and T.-L. Sheu, “A modified EDCA with dynamic contention control for real-time traffic in multi-hop ad hoc networks,” submitted to Journal of Information Science and Engineering . (SCI)
6.C.-Y. Chi and Mei-Chyn Wu, “Inverse filter criteria for blind deconvolution and equalization using two cumulants,” Signal Processing , vol. 43, no. 1, pp. 55-63, April 1995. (SCI)
Conference Papers:
1.
T.-L. Sheu and Yang-Jing Wu, “A channel preemption model for multimedia traffic in mobile wireless networks,” Proc. of 10th IFIP Conference on Personal Wireless Communications , pp. 457-464, Colmar, France, 25-27 Aug. 2005.
2.
T.-L. Sheu and Yang-Jing Wu, “Channel allocations with preemption for multimedia traffic in mobile wireless networks,” Proc. of CIIT 2004 , St. Thomas, US Virgin Islands, 22-24 Nov. 2004
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