Bài giảng Mạng máy tính căn bản - Chương 4: Kiểm tra cáp (Cable testing) trình bày tổng quan về networking, cung cấp một số định nghĩa cơ bản để về kiểm tra cáp, mô tả các vấn đề liên quan đến việc thử nghiệm phương tiện truyền thông được sử dụng cho kết nối trong mạng cục bộ (LAN),. | Chương 4 KIỂM TRA CÁP (Cable testing) OverView Networking media is literally and physically the backbone of a network. Inferior quality of network cabling results in network failures and unreliable performance. Phan Vĩnh Thuần Copper, optical fiber, and wireless networking media all require testing to determine the quality. These tests involve certain electrical and mathematical concepts and terms, such as signal, wave, frequency, and noise. Understanding this vocabulary is helpful when learning about networking, cabling, and cable testing. The goal of the first lesson in this module is to provide some basic definitions so that the cable testing concepts presented in the second lesson will be better understood. Phan Vĩnh Thuần The second lesson of this module describes the issues relating to the testing of media used for physical layer connectivity in local-area networks (LANs). In order for the LAN to function properly, the physical layer medium must meet the industry . | Chương 4 KIỂM TRA CÁP (Cable testing) OverView Networking media is literally and physically the backbone of a network. Inferior quality of network cabling results in network failures and unreliable performance. Phan Vĩnh Thuần Copper, optical fiber, and wireless networking media all require testing to determine the quality. These tests involve certain electrical and mathematical concepts and terms, such as signal, wave, frequency, and noise. Understanding this vocabulary is helpful when learning about networking, cabling, and cable testing. The goal of the first lesson in this module is to provide some basic definitions so that the cable testing concepts presented in the second lesson will be better understood. Phan Vĩnh Thuần The second lesson of this module describes the issues relating to the testing of media used for physical layer connectivity in local-area networks (LANs). In order for the LAN to function properly, the physical layer medium must meet the industry standard specifications. Phan Vĩnh Thuần Attenuation (signal deterioration) and noise (signal interference) cause problems in networks because the data is not recognizable when it is received. Proper attachment of cable connectors and proper cable installation are important. If standards are followed in these areas, attenuation and noise levels are minimized. Phan Vĩnh Thuần . Cơ sở nghiên cứu kiểm tra cáp dựa vào tần số (Background for Studying Frequency-Based Cable Testing) . Sóng (Wave) Networking professionals are specifically interested in voltage waves on copper media, light waves in optical fiber, and alternating electric and magnetic fields called electromagnetic waves. The amplitude of an electrical signal still represents height, but it is measured in volts instead of meters. The period is the amount of time to complete one cycle, measured in seconds. The frequency is the number of complete cycles per second, measured in Hertz. Phan Vĩnh Thuần . Sóng sin .
