Môi trường vật lý trong mạng máy tính

1
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Môi trường vậtlý
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Lý thuyếtcơ bảncủatruyềndữ liệu
• Phân tích Fourier
•Tínhiệu trong môi trường băng thông hạnchế
•Tốc độ truyềntối đacủa kênh
2
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Tín hiệukhibăng thông hạnchế
Tín hiệusố và biên độ trung bình bình phương phổ Fourier
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Tín hiệukhibăng thông hạnchế
3
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Quan hệ giữatốc độ truyềnvàcáchàibậccao
Tín hiệukhibăng thông hạnchế
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Môi trường truyềndữ liệu
• Điệntừ trường
•Cápđôi dây xoắn
•Cápđồng trục
• Cáp quang
4

Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cáp đôi dây xoắn
(a) Category 3 UTP.
(b) Category 5 UTP.
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cáp đồng trục
5
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cáp Quang
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Truyềndẫn ánh sáng trong sợi quang
Suy hao anh sáng qua sợi quang
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Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cáp quang
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
So sánh giữa nguồn sáng điốtbándẫnvàLED
Cáp quang
7
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Mạng quang
Vòng kếtnối quang vớitrạmlặpchủđộng
Hanoi University of Technology Faculty of Electronics and Telecommunications

1/2008
Truyềndẫn không dây
•Phổđiệntừ trường
• Radio Transmission
• Microwave Transmission
• Sóng hồng ngoại và sóng millimeter
• Lightwave Transmission
8
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Phổđiệntừ trường
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Radio Transmission
(a) Với sóng VLF, LF, và MF, sóng radio đi theo bề mặt đất
(b) Vớidải sóng HF, chúng phảnxạ tầng điệnly
9
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Lightwave Transmission
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
The Local Loop: Modems, ADSL và Wireless
10
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Modems
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
(a) QPSK.

(b) QAM-16.
(c) QAM-64.
Modems
11
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
(a) V.32 for 9600 bps.
(b) V32 bis for 14,400 bps.
(a)
(b)
Modems
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Digital Subscriber Lines
Quan hệ củabăng thông và khoảng cách trên cáp Category 3 UTP
12
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Digital Subscriber Lines
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Wireless Local Loops
13
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Frequency Division Multiplexing
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Wavelength Division Multiplexing
14

Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Time Division Multiplexing
T1 (1.544 Mbps).
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cable Television (TV cáp)
• Internet trên hệ thống TV cáp
• Phân bố tầnsố
• Cable Modems
•ADSL so vớiCable
15
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Hệ thốngTV cáp sơ khai
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Internet trên hệ thống TV cáp
16
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Fixed telephone system.
Internet trên hệ thống TV cáp
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Phân bố phổ
17
Hanoi University of Technology Faculty of Electronics and Telecommunications
1/2008
Cable Modems