Page 144 - Computer_Science_F5

through which the data is transmitted. At the appropriate bit patterns, encoding
its core, the Physical layer is concerned methods, and interface characteristics
with converting the binary data (1s and for each type of medium. For example,
0s) into signals that can be transmitted Ethernet is a commonly used protocol Chapter Three: Advanced Computer Networks
over different types of communication for wired communication, while Wi-Fi is
FOR ONLINE READING ONLY
media. These signals can take various used for wireless communication. These
forms depending on the medium used, protocols specify the electrical, optical, or
such as electrical voltages, light pulses, radio signals that represent the binary data
or radio waves. The Physical layer and define how devices should interpret
ensures that these signals are properly and process these signals.
generated, encoded, and transmitted to
the receiving device. Characteristics of the physical layer
The physical layer encompasses
The representation of bits in the Physical four crucial aspects for establishing,
layer is such that, each bit is assigned a maintaining, and terminating a physical
numerical value of either 1 or 0. These connection between end systems:
binary values form the basic building 1. Mechanical: Pertains to the
blocks of digital communication. The physical attributes of the interface
Physical layer works with these bits, to a transmission medium, usually
organising them into frames or packets described as a pluggable connector
that can be transmitted over the network. that connects one or more signal
conductors, known as circuits.
The Physical layer communicates directly 2. Electrical: Concerns the
with different types of communication representation of bits, such as voltage
media, including copper wires, fibre levels, and the bit transmission rate.
optic cables, and wireless channels. 3. Functional: Defines the functions
Each type of medium has its own unique carried out by individual circuits
of the physical interface between
characteristics, such as bandwidth, data a system and the transmission
rate, and transmission range. The Physical medium.
layer interacts with these media by 4. Procedural: Details the sequence of
converting the binary data into appropriate events for exchanging bit streams
signals that can be transmitted over the across the physical medium.
specific medium.

The physical layer defines network
To ensure proper communication over devices, interfaces between network
different media, specific protocols medium and devices, and defines optical,
are needed. These protocols define electrical, and mechanical characteristics.

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Student’s Book Form Five

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