G9576619

"Homework 12/22/2007"

1. Compare the business models of Metropolitan Wi-Fi Networks in the world.

With the advancement of wireless technology, recent years have witnessed an ever-increasing popularity of wireless net­works, including wireless local area networks, mobile ad hoc networks, wireless sensor networks, and wireless mesh networks. Wireless local area networks, or Wi-Fi hot spots, have been widely deployed in cities, college campus, air­ports, coffee bars, conference halls, hotels, and many other public places. However, communication in wireless local area networks is still limited to one-hop wireless communication between clients and access points, which restricts wireless access to a small range around access points. If mobile devices are allowed to forward packets for others, a mobile ad hoc network can be formed, and the range of wireless access to Wi-Fi hot spots can be significantly extended. This kind of wireless multihop communication is also common in wireless sensor networks that are often used in many applications such as environmental monitoring and health care. Recently, metropolitan Wi-Fi wireless mesh networks have become hot research topics because they can provide affordable outdoor wireless broadband Internet access to residents, businesses and visitors in a large area through a wireless multihop backhaul
This work was supported in part by the U.S. Office of Naval Research under Young Investigator Award N000140210464 and by the National Science Foundation under Faculty Early Career Development Award ANI-0093241 and under grant DBI-0529012.
mesh structure. In this paper, we refer to all these networks that support multihop wireless communications as wireless multihop ad hoc networks and study how to improve their performance.
2. Read the abstracts of the full papers, and then make your comments.Robin Kay, Developing a comprehensive metric for assessing discussion boardeffectiveness, British Journal of Educational Technology, Vol 37 No5 2006. pp. 761-783

這篇paper花了一年的時間將45個學生, 年齡在 13-15歲分成兩組做研究。分類為social learning/congnitive processing/quality of discussion/Initial question/role of educator/navigation issues/challenges for students/types of users/attitudes towards discussion/response time/learning outside of school/learning performance根據研究的結果, 論壇上討論的事項大多是有關上課或是超出課程範圍的事, 會回應的不多，看的人佔大多數主要的討論是問問題或是提供答案，有些人習慣是自行上網查尋或是直接問同學。和BLOG相比較，BLOOG具有較大的自我空間

posted by Claire @ 7:54 PM