Browsing by Author "Wu, HL"

Now showing 1 - 3 of 3

A wireless video relay system at 28 GHz
(2001)
Hu, CH
;
Wu, HL
;
Chang, CY
;
Chung, SJ
;
電信工程研究所
LMDS (Local Multipoint Distribution Service) system can offer subscribers variety of one-way or two-way broadband services, such as video programming distribution, high speed data transmission, and wireless local loop telephony. LMDS centered around the 28 GHz band is the fastest, most flexible and economical broadband network that can be developed today. From last year, NCTU (National Chiao Tung University) was engaged in a four-year project, co-sponsored by the Ministry of Education and National Science Council, ROC, investigating the advanced millimeter-wave circuits and systems. Part of the work is to be implemented on the LMDS system as a platform. This paper presents some of the preliminary results.
Design and implementation of two-tier Mobile Ad Hoc Networks with seamless roaming and load-balancing routing capability
(2004)
Hsu, YY
;
Tseng, YC
;
Tseng, CC
;
Huang, CF
;
Fan, JH
Due to its flexibility, Mobile Ad Hoc Network (MANET) has attracted a lot of attention recently. Most existing works, however, limit a MANET as a stand-alone network. In this paper, we propose a two-tier MANET by extending the connectivity of the MANET to the Internet. Some hosts in the MANET are equipped with cellular interfaces and are called gateways, which can provide Internet connections. Such extension would greatly improve the connectivity of MANET To maintain seamless connectivity, we modify the Mobile IP to make traversing private networks (i.e., NAT) of cellular networks possible. We also propose a load-balancing routing protocol to utilize the cellular interfaces of gateways, which are likely to be bottlenecks to the Internet. A prototype is implemented and performance results obtained from the testbed is reported.
On the Jensen-Shannon divergence and variational distance
(2005-09-01)
Tsai, SC
;
Tzeng, WG
;
Wu, HL
;
資訊工程學系
;
Department of Computer Science
We study the distance measures between two probability distributions via two different distance metrics, a new metric induced from Jensen-Shannon divergence, and the well known L-1 metric. We show that several important results and constructions in computational complexity under the L-1 metric carry over to the new metric, such as Yao's next-bit predictor, the existence of extractors, the leftover hash lemma, and the construction of expander graph based extractor. Finally, we show that the useful parity lemma in studying pseudorandomness does not hold in the new metric.