OSI Physical Layer

Network Fundamentals – Chapter 8

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Objectives
 Explain the role of physical layer protocols and services in supporting communication across data networks.
 Describe the role of signals used to represent bits as a frame as the frame is transported across the local media.  Describe the purpose of physical layer signaling and encoding as they are used in networks.  Identify the basic characteristics of copper, fiber and wireless network media.  Describe common uses of copper, fiber and wireless network media.
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Outline
 Physical layer: Communication signals
–Purpose of the physical layer –Physical layer standards –Physical layer fundamental principles

 Physical signaling and encoding: Representing bits
–Signaling bits for the media –Encoding: Grouping bits –Data-carrying capacity

 Physical media: Connecting communication
–Types of physical media
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–Media connectors

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Purpose of the Physical Layer
 The roles of the OSI physical layer:
–To encode the binary digits that represent data link layer frames into signals. –To transmit and receive these signals across the physical media.

 There are various types of physical media and they carry different types of signals.
–Copper cable – electrical voltage. –Fiber optic – light pulses. –Wireless – electromagnetic waves.

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 Physical layer will encode the binary data in a frame to the proper type of signal depending on the physical media used.
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Purpose of the Physical Layer

ITE PC v4.0 Chapter 1

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