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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jss.2006.09.041 Byline: Chun-Chuan Yang, Yung-Chi Wang, Chih-Wen Tien Keywords: Synchronized multimedia; SMIL2.0; Real-time synchronization model Abstract: A novel synchronization model namely Extended Real-Time Synchronization Model (E-RTSM) for modeling SMIL2.0 temporal behaviors is proposed in this paper. E-RTSM deals with event-based/non-deterministic synchronization as well as schedule-based synchronization in SMIL2.0. Converting of the temporal relationship of a SMIL2.0 document to E-RTSM is presented. Moreover, design of the E-RTSM-based data-retrieving engine for SMIL2.0 presentations is also proposed in the paper. The data-retrieving engine estimates the worst-case playback time of each object at the parsing stage and applying an error compensation mechanism at run-time to adjust the estimated playback time as well as the schedule of the fetching requests for data retrieval. Performance measurements from the real implementation of the E-RTSM-based data-retrieving engine for SMIL2.0 presentations have demonstrated the efficiency of the proposed technique. Author Affiliation: Multimedia and Communications Laboratory, Department of Computer Science and Information Engineering, National Chi-Nan University, 1, University Road, Puli, Nantou County 545, Taiwan, ROC Article History: Received 25 November 2005; Revised 30 September 2006; Accepted 30 September 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2006.10.007 Byline: Chun-Chuan Yang (a), Chun-Shian Tsai (b), Junn-Yen Hu (a)(b), Tzu-Chien Chuang (a)(b) Keywords: 802.16; BWA; Mobility management; Wireless overlay network; Vertical handoff Abstract: In this paper, we investigate the characteristics of IEEE 802.16 and conclude that it is better to equip BS (base station) and SS (subscriber station) with Layer 3 functionality. Therefore, an 802.16 network can act as the backbone network of different subnets for better deployment. Based on the two IEEE Specifications, 802.16-2004 and 802.16e, we propose two kinds of paradigms of the 802.16 network technology for mobile networking. In the first paradigm, a novel concept called middle-domain mobility management in between macro- and micro-domain for 802.16-2004 is proposed. The management scheme of middle-domain is designed to accommodate different micro-mobility protocols in an 802.16-2004 network environment. Moreover, a mathematical analysis and simulation study are presented for performance evaluation. In the second paradigm, by comparing with traditional overlay networks (e.g. GPRS/WLAN), we have found that the characteristics for the 802.16e/802.11 overlay network are actually different from traditional overlay networks. To provide more efficient vertical handoff, a novel protocol called speed-based vertical handoff scheme (SVH) is proposed. A Simulation study has demonstrated that SVH can achieve a better performance than its WLAN-first counterpart in terms of less signaling and fewer packet losses. Author Affiliation: (a) Department of Computer Science and Information Engineering, National Chi Nan University, #1, University Road, PULI, Nantao 545, Taiwan, ROC (b) Department of Computer Science and Information Engineering, Chung Chou Institute of Technology, Taiwan, ROC Article History: Received 2 May 2006; Revised 4 October 2006; Accepted 13 October 2006 Article Note: (footnote) [star] This work was supported in part by the National Science Council, Taiwan, R.O.C., under grant no. NSC94-2219-E-260-004.