Physical Layer in Computer Networks PDF
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Physical Layer in Computer Networks PDF

Want to download Physical Layer in Computer Networks PDF? well, here I have provided you an overview of physical layer pdf so go through the overview and you can download pdf

The OSI Model (Open System Interconnection Model) can be divided broadly into two layers, namely Upper layer and Lower Layer. The lower layer of OSI Model mainly deals with the transportation data issues.

In the Lower Layer, lies the Physical layer. The physical layer manifests mainly at the hardware level and has a software component too. This layer is tangible in the sense that it is placed at the lowest level and deals with the physical medium. Its main responsibility is to place information on the physical medium, as it is on the medium through which the bits are transmitted. This layer establishes, maintains and deactivates the physical connection. The specifications for electrical, mechanical, and procedural network interface are given in this layer.

The Physical Layer includes everything ranging from type of cables, radio frequency link or wireless system specifications, to layout of pins, voltages and other practical physical requirements. In fact, if there is a network problem, then this is the first layer which is inspected for any possible faults. It is checked if all the components, such as wires, cables, hubs, routers, switches etc are connected properly, power supply is there or not, among other things. By the way, Hub, Repeater, Modem, Cables are Physical Layer devices.

The data is transmitted over the physical layer in the form of bits, that is, in the form of Zeros and Ones. This layer is responsible for the transmission of individual data from one node to the next. Once the signal is received by this layer, it converts it into bits and send them the next layer, i.e. the Data Link Layer. The Data Link Layer would then put those bits into proper frames for further use and processing.

This is an overview of the Physical Layer in Computer Networks PDF, if you want to read full article in pdf, we have provided download link below.

The OSI physical Layer

  • Repeaters, hubs, and multiplexers, which regenerates electrical signals.
  • Transmission media connectors, which regenerate electrical signals, interconnect devices to the transmission media.
  • Modems and codecs, which performs Digital and Analog conversions.

The functions of Physical Layer are as below:

  1. Representation of Bits: Streams of bits represents the data in this layer. For the purpose of transmission, the bits must be encoded into signals. The determination of the type of encoding is done at this layer, i.e. here it is decided how the 0s and 1s are changed to signal.
  2. Bit Synchronisation: There needs to be a synchronisation of the bits between the sender and receiver. This layer achieves this by providing a clock.
  3. Bit Rate Control: The number of bits sent per second is also defined at the Physical Layer. This is also known as the transmission rate.
  4. Line Configuration: The types of configuration for connection of devices with the medium are: Multipoint Connection and Point-to-Point Connection.

In a point to point connection, a direct link is established between the two devices, e.g. when a computer is attached to a printer, it is a point to point link. In this connection, each station is guaranteed a specific transmission capacity or bandwidth.

This is an overview of the Physical Layer in Computer Networks PDF, if you want to read full article in pdf, we have provided download link below.

In a Multipoint connection, link is established between three or more devices. For example, in a Bus connection, multiple devices are connected to the common trunk of the bus. Here, bandwidth is shared between the devices.

  1. Physical Topologies: The devices connected physically to the system, are arranged in various patterns of physical connection. This is done keeping in mind some characteristics such as: relative ease of installation, ease of configuration, ease of troubleshooting, potential number of units which could be affected by media failure.

These patterns include Star, Mesh, Ring, Bus, Tree or other hybrid combination of these forms. All these topologies have their relative advantages and disadvantages.

  1. Transmission Mode: In the physical layer it is defined depending on the direction of transmission between two devices. It can be Full Duplex, Half-Duplex and Simplex.

Physical Layer in OSI Model- The physical layer is the first layer of the Open Systems Interconnection (OSI) Model depending on which end you decide to start your counting. It holds a significant role in the functioning of the OSI Model. As suggested by the name, it has a physical body that consists of circuits and technologies of the network. To know more about the Physical Layer in the OSI Model, keep reading this article till the end.

This is an overview of the Physical Layer in Computer Networks PDF, if you want to download we have provided link below.

Most of the time, the physical layer is installed in the form of a chip. This chip is called PHY (Chip), an abbreviation for ‘Physical Layer’.

The role assigned to the Physical Layer is to deal with the physical connectivity of two different stations with interacting with hardware and mechanism of the signal, making it the only layer to be capable of doing so.

All the Layers in the model work on the data or functions provided by the lower layer and provides its’ services to the layer above itself. Being the lower-most layer, the physical layer only provides the service to the data link layer in the form of raw bits or electrical pulses instead of data packages like some of the other layers.

The electrical pulses are representative of the binary data that can be sent over both the wireless and the wired network and media.

Physical Layer in OSI Model in networking

Despite being named the physical layer, it does not deal with the actual physical mediums such as fiber and copper.

Below are the functions of the physical layer

  1. Bit-by-bit or Symbol-by-Symbol delivery.
  2. Convention from one form to another of a signal so it could be interpreted and sent over communication to the other party.
  3. It also functions in the process of error-correcting and channel coding.
  4. Line coding allows the transmission of the data through a hardware device and the physical layer to provide its’ service in that matter as well.
  5. When the signal is multiplexed digital, it functions as a controlled or the multiplex hardware control and switches circuit where need be.
  6. The power of auto-negotiation to an extent is also provided to this layer.
  7. It also deals with the synchronization of the transmitter and receiver.
  8. It holds the ability to control; start-stop flow control of the signal.
  9. Whether a collision has happened or is about to happen has to be detected and the physical layer is responsible for that job as well. What it really detects is the carrier availability and by doing so it can avoid the congestion caused by the packages that are now undeliverable.

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