The physical layer is concerned with transmission of which over the physical medium
Physical layer in the OSI model plays the role of interacting with actual hardware and signaling mechanism. Physical layer is the only layer of OSI network model which actually deals with the physical connectivity of two different stations. This layer defines the hardware equipment, cabling, wiring, frequencies, pulses used to represent binary signals etc. Show Physical layer provides its services to Data-link layer. Data-link layer hands over frames to physical layer. Physical layer converts them to electrical pulses, which represent binary data.The binary data is then sent over the wired or wireless media. SignalsWhen data is sent over physical medium, it needs to be first converted into electromagnetic signals. Data itself can be analog such as human voice, or digital such as file on the disk.Both analog and digital data can be represented in digital or analog signals.
Transmission ImpairmentWhen signals travel through the medium they tend to deteriorate. This may have many reasons as given:
Transmission MediaThe media over which the information between two computer systems is sent, called transmission media. Transmission media comes in two forms.
Channel CapacityThe speed of transmission of information is said to be the channel capacity. We count it as data rate in digital world. It depends on numerous factors such as:
MultiplexingMultiplexing is a technique to mix and send multiple data streams over a single medium. This technique requires system hardware called multiplexer (MUX) for multiplexing the streams and sending them on a medium, and de-multiplexer (DMUX) which takes information from the medium and distributes to different destinations. SwitchingSwitching is a mechanism by which data/information sent from source towards destination which are not directly connected. Networks have interconnecting devices, which receives data from directly connected sources, stores data, analyze it and then forwards to the next interconnecting device closest to the destination. Switching can be categorized as: What is the role of physical layer in transmission?The physical layer is responsible for sending computer bits from one device to another along the network.
Which layer determine how physically data is transferred over the medium?The transport layer. The transport layer is responsible for transferring data across a network and provides error-checking mechanisms and data flow controls. It determines how much data to send, where it gets sent and at what rate. TCP within the TCP/IP suite is the best-known example of the transport layer.
Is concerned with the movement of over the physical medium?The physical layer is concerned with the movement of over the physical medium.
How is data transmitted in the physical layer?Physical layer provides its services to Data-link layer. Data-link layer hands over frames to physical layer. Physical layer converts them to electrical pulses, which represent binary data. The binary data is then sent over the wired or wireless media.
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