Physical Layer in OSI Model: Functions, Devices, Example, Layer 1 in OSI Model

Physical Layer in OSI Model: Functions, Devices, Example, Layer 1 in OSI Model

What is Physical Layer

Definition: Physical layer is a layer 1 in the OSI model that plays major activity for interacting along with hardware components and signal mechanism system. This layer actually deals with making connection of two distinct station points. Physical layer specifies the hardware resources, frequencies, pulse, and cabling which are represented to binary signal like as 0’s and 1’s.

Read More – What is OSI Network Model with 7 Layers

Physical layer delivers own services to Data link layer then DLL layer provides all frames to physical layer, and physical layer alters them into electrical pulse which like as binary form, and finally these binary data is moved to wired or wireless transmission media.

Signal Transmission

In the physical layer, two distinct types of techniques are used for signal transmission over the network. Such as –

  • Baseband Signaling

In this method, we have to both rights send and receive data over single line in order but before transmitting data on the distinct time frame, we must be divided those data, and this process is known as “Time Division Multiplexing”. Best example of baseband signaling is Ethernet that is used in the Local Area Network technology.

  • Broadband Signaling

In the broadband signaling method, we can use only one line for sending and receiving signal via different frequencies for outgoing and incoming data, so it is known as “Frequency Division Multiplexing”. Its best example is “Television”.

Functions of Physical Layer 

 Here, we will explain main functions of physical layer 1 in OSI model and working as well; below explain each one-

physical layer function
Bit Synchronization: This layer helps to allow synchronization of all bits which are delivered with clock, and this clock has ability to manage both receiver and sender that is producing synchronization on bit level.

Representation of Bits: This layer consists data like as stream of bits, and before transmission of those data must be encoded into signals such as 0’s and 1’s are converted into signal.

Interface: Physical layer also produces the transmission interface in between different network devices and transmission source.

Bit Rate Control: Physical layer can pre-defined transmission rate of flowing all bits such as how many bits can be sent in per second.

Line Configuration: Physical layer allows establishing connection with different sources (medium) like as Point to Point configuration and Multipoint configuration.

Physical Topologies: Physical layer defines the physical layout structure of different types of components (devices/nodes), which are managed over the network like as ring, star or mesh, bus topology etc.

Transmission Mode: Physical layer also specifies the mode where to flow all data in between multiple linked network devices. It allows some transmission modes like as simplex, half-duplex and full-duplex.

  • Simplex Mode: Here, communication is done only one direction, so it is known as “Unidirectional Communication”.
  • Half Duplex Mode: Here, both station (Receiver and Sender) are capable to receive and transmit data.
  • Full Duplex: Here, communication is done both sides at same time duration.

Physical Layer Devices and Components

Here, Physical layer devices list, which are used in Physical layer1; such as-

Physical Layer Examples of their Devices are:

  • Hub: Hubs are mostly used to make connection for LAN network, and it has several input/output ports. Hub has three variants like as Passive hub, Active hub, and intelligent hub.
  • Repeater: This device is used to transmission system for regaining analog or digital signal distorted by transmission loss. Analog repeaters are capable only to amplify the signal but other digital repeaters have ability to regain a signal to near its better quality.
  • Cables and Connectors: Cables and Connectors helps to connect multiple devices with each other like as Copper cable, Coaxial cable, Ethernet cable, Shielded Twisted Pair Cable, Unshielded Twisted Pair Cable.
  • Mostly two types of connectors are used like as RJ-45 and BNC.
  • Modem: It stands for modulator/demodulator. Modem is a hardware component that helps to send and receive information over the telephone line.
  • Network Interface Cards (NIC): It allows to your computer system to make connection with network system.
  • Transmitters: Transmitter is electronic devices that deliver radio waves through antenna.
  • Multiplexers: Multiplexer is a hardware component that has multiple analog and digital input signals and finally single output switch.
  • Receivers: Receiver is a hardware device that is used for receiving signals like as analog electromagnetic signals or waves, or digital signals.
  • Transceivers: It is also electronic device that helps to perform both functions like as transmits and receives analog or digital signals.
  • Couplers: Couplers are furnished with mandatory protection equipment in order to secure the equipment when being unmated and in-service and to prevent calcareous buildup and marine growth.