The physical layer is the lowest layer of the OSI model (Open Systems Interconnection Model). It establishes wired and wireless connections with the hardware of various computers connected to the network as well as transfers all the information from one machine to another in the form of signals.
The physical layer receives data, information, or files within the sort of a frame from the info Link layer. After this, these frames are converted into binary numbers and this binary number is transferred from one computer to a different using various communication mediums within the sort of electric signal. In this, wired like cable or wired and wireless communication mediums like Wi-Fi or Bluetooth, etc. are often used for the transfer of knowledge.
Characteristics of Physical Layer
- As you might know that the computer understands the binary language, so the physical layer transfers all the information from one computer to another computer in the form of binary language (0 and 1). It has nothing to do with the meaning of those information, its job is only to transfer the information.
- The physical layer can use either a wired or a wireless medium to receive or communicate information.
- It establishes a physical connection with all the machines physically connected to the network such as computers, laptops, printers, scanners etc.
- It works for communication using hardware devices like wire, network adapters, ethernet, repeaters, networking routers but it is not responsible for any issuse of these hardware devices.
- It is not responsible for the any mistakes in the transmission of data, the machines between which the information has to be transmitted, whether all the machines are ready or not, it is checked by other layers. The physical layer only works to transfer the information.
- This layer is not relate to any type of Files or Email Transfer Protocol, other higher level layers are responsible for these things. For example, we know that the application layer is responsible for the Files or Email Transfer Protocol.
Functions of Physical Layer
- The work of the physical layer is that this upper layer converts all the information received from the data link layer into signals and transmits it from one computer to another using a communication medium such as a wire or wireless medium.
- It controls the speed of transfer of data, means that the physical layer is responsible for controlling how many bits of information per second the machine has to transfer.
- This layer is establish a common connection between the sender of the information and the receiver of the information, so that the information can be passed to the receiver without any problems.
- How to organize different types of devices to connect to the network means to choose from the network topology such as Mesh, Star, Ring and Bus to establish the connection in the network. It helps in deciding.
- Signals are mainly of two types, Analog Signals and Digital Signals, the decision of which one to use to transfer information is also taken by the physical layer.
- There are a total of three types of transmission modes in computer networks such as Simplex, Half Duplex and Full Duplex.
- It also avoids conflicts between information flowing in the network due to data packets becoming undeliverable.
Examples of Tools that use physical layers
- Hub:- It is also called network hub. It has many connection points in which various devices are connected to the network by putting wires. So that the information can be transferred.
- Repeater:- With distance and time, the capacity of the signals flowing in the communication medium decreases, so the capacity of the signals is increased with the use of repeater, that is why they are also called signal boosters.
- Modem:- It converts digital signals into analog signals
- Cables:- Cable or wire is a medium using which data, information or files sent by a computer travels.