第10章 Internet接入技术（Chapter 10 Internet access technology）.doc

第10章 Internet接入技术（Chapter 10 Internet access technology） Chapter 10 Internet access technology Short-answer questions: 1. What kinds of Internet access technologies based on telephone copper wire? 2. Describe the working principle of 56KbpsModem? 3. What are the two categories of XDSL access technology? 4. What are the three independent information channels for ADSL? 5. Compare the differences of several XDSLS from the four aspects of using the logarithm of transmission line, the ascending rate, the descending rate and the effective transmission distance. 6. What are the two main categories of optical fiber access network? 7. What are the three types of access to optical access network system? 8. What are the types of application of optical fiber access network? 9. What is HFC access technology? 10. Explain how CableModem works. 11. What are the problems for Ethernet Internet access network based on Ethernet LAN? 12. What is MMDS? What are its characteristics? 13. What is LMDS? What are its features? 14. What is GPRS? What are its characteristics? What is CDMA? What are its characteristics? 16. What kinds of technologies are in 3G mobile 3G? 17. What are the main applications of VSAT system in Internet access? Short-answer questions: 1. Currently popular copper wire access technologies include the following: LAN access technology Ethernet/high-speed Ethernet transmission medium is double stranded, copper shaft and optical fiber. The current widely used and the best performance ratio is the double stranded wire network, the Ethernet technology is transmitting the base band digital signal directly on the transmission medium, the transmission distance of the five lines is 100 meters. High speed digital subscriber line (HDSL) technology The encoding type for HDSL 2 b1q code or CAP code, can use the existing two pairs from the telephone cable subscriber line to provide full duplex T1 / E1 signal transmission, 0.4 0.6 mm wire diameter for the average user line, the transm