ITM 301 Chapter 2: Chapter 2 Physical Layer.docx

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 301
• Professor: Franklyn Prescod

Document Summary

No transmission facility can transmit signals without losing some power in the process. Distortion: all transmission facilities diminish different fourier components by different amounts. For wires, the amplitudes are transmitted mostly undiminished from 0 up to some frequency (measured in cycles/sec or hertz) with all frequencies above this cutoff attenuated. Bandwidth: the width of the frequency range transmitted without being strongly attenuated. The cutoff is not really sharp, so the quoted bandwidth is usually from 0 to the frequency at which the received power has fallen by half. Bandwidth is a physical property of the transmission medium that depends on the construction, thickness, and length of a wire or fiber. Filters are used to further limit the bandwidth of a signal which allows more signals share a given region of spectrum which improves the overall efficiency. Baseband: signals that run up from 0 to maximum frequency. Passband: signals that are shifted to occupy a higher range of frequencies (wireless transmissions)