Browsing by Author "Chuang, BW"

Now showing 1 - 3 of 3

A novel approach of backup path reservation for survivable high-speed networks
(2003-03-01)
Lo, CC
;
Chuang, BW
;
交大名義發表
;
National Chiao Tung University
For high-speed networks, a restoration mechanism based on backup path provides a, means for assuring their survivability. In this article, we propose a two-phase BP reservation mechanism for high-speed networks. In the admission phase, a pair of working path and backup path is selected from the provisioned sets of WPs and BPs. In the adjustment phase, if backup capacity utilization exceeds the preset threshold, BP assignments are rearranged to optimize the usage of backup capacity. A mathematical model is formulated to verify the quality of the optimized solutions. Computational experiments indicate that the proposed mechanism significantly reduces the consumption of backup capacity while still maintaining a high degree of survivability. Moreover, experiments show that the optimized solutions obtained are on average within 3.6 percent of optimal.
An adaptive survivability admission control mechanism using backup VPs for self-healing ATM networks
(2002)
Lo, CC
;
Chuang, BW
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Restoration mechanism based on backup capacity provides a solution for assuring network survivability. In this paper we propose an adaptive survivability admission control mechanism using back-zip virtual paths for self-healing Asynchronous Transfer Mode (ATM) networks. Working virtual paths (WVPs) and backup virtual paths (BVPs) are configured during the network design phase. For each call request, the proposed mechanism selects a pair of WVP and BVP, followed by bandwidth reservation for the pair only if both the WVP and the BVP selected succeed in the call admission Control. A backup dependency, matrix (BDM) is suggested for recording the most up-to-date information of backup capacity, required on a link for restoring a failure 017 other links. However backup capacity, actually, reserved on a link is shared by all BVPs passing the same link. This "sharing" concept substantially, reduces the amount of backup capacity, required The selection of BTT uses the BDM so as to make the selection adaptive to the current traffic loads on the network Two BVP selection methods, min-cost and min-expectation, are proposed, The min-cost strategy, increases network utilization while maintaining full survivability, under a single link failure. On the contra 3,, the min-expectation strategy, enhances network survivability, by slightly, reducing network utilization. Simulation results indicate that the proposed mechanism guarantees a 100 percent survivability, under any single link failure and supports an zip to 83 percent survivability, under double link failures, Above all, this mechanism not only, acquires desired survivability, but also at the same time keeps satisfactory, network utilization.
System development and performance investigation of mobile ad-hoc networks in vehicular environments
(2005)
Chuang, BW
;
Tarng, JH
;
Lin, J
;
Wang, C
;
傳播研究所
This paper presents the methodology of implementations and performance measurements of our mobile ad-hoc network (MANET) platforms. The work is prompted by the lack of published results concerning the issues associated with the implementation of MANET facilities on actual wireless networks, as opposed to results of simulation experiments. Our MANET is developed based on the settled IEEE 802.11b technology operating in the ad-hoc mode. The opportunity driven multiple access (ODMA), which is developed by IWICS Inc., is implemented on the platform and its performance has been examined through field tests along city streets. Based on the measurement results, ODMA-based MANET facilities are able to provide satisfactory wireless communication services in vehicular environments. The minimum data throughput of 20kBytes/sec could be guaranteed in our testbed.