无线网络北邮国际学院.ppt

1、Wireless Network,Zhiyong Feng ,Course informations,Textbook W. Stallings, Wireless Communications and Networks, 2nd Edition, Pearson Prentice Hall, 2006. References T. S. Rappapot, Wireless Communications principle and practice, 2nd Edition, Pearson Education 2006. A. Goldsmith, Wireless communicati

2、ons, Cambridge University Press, 2005.,Course schedule,Signal transmissions Introduction to wireless communication systems Fundamentals of signal transmissions Radio Large-scale path loss, Small-scale path loss Diversity Principles of spread spectrum communications Techniques for wireless communicat

3、ions Multiple access strategies Communication networks: switch, protocol, traffic analysis Wireless networks and standards Statellite networks Cellular networks: GSM, IS-95, IMT-2000 WLL, WAP IEEE 802.11 Bluetooth,Grading,Homework Experiments Final Exam,Wireless Comes of Age,Marconi invented the wir

4、eless telegraph in 1896 (but Tesla 1893!) Communication by encoding alphanumeric characters in analog signal Sent telegraphic signals across the Atlantic Ocean Communications satellites launched in 1960s Voice, TV Advances in wireless technology Radio, television, mobile telephone, communication sat

5、ellites More recently Satellite communications, wireless networking, cellular technology,Figure 1.1 The growth of mobile telephony as compared with other popular inventions of the 20th century.,Broadband Wireless Technology,Higher data rates obtainable with broadband wireless technology Graphics, vi

6、deo, audio Shares same advantages of all wireless services: convenience and reduced cost Service can be deployed faster than fixed service No cost of cable plant Service is mobile, deployed almost anywhere,What is wireless communication?,Communicate by electrical magnetic wave Mobile cellular phone

7、systems GSM, CDMA , DAMPS Wireless Local Area Network(WLAN) Satellite communication Direct TV Bluetooth Wireless broadcasting Cordless telephone system Paging system ,Character of wireless communications,Mobile terminal Open environment Area coverage Security problem: everybody can hear from the air

8、 Different propagation environments Office、city、rural area Different transmission quality,Limitations and Difficulties of Wireless Technologies,Wireless is convenient and less expensive Limitations and political and technical difficulties inhibit wireless technologies Lack of an industry-wide standa

9、rd Device limitations E.g., small LCD on a mobile telephone can only displaying a few lines of text E.g., browsers of most mobile wireless devices use wireless markup language (WML) instead of HTML,Satellite communications,Challenges,Lack of an industry-wide standard Device limitations Eg., small LCD Political difficulties Technical difficulties Multipath fading channel System interference Mobility management Radio resource management ,Mobile radio system around the world,The