The Wavelength Division Multiplexing (WDM) is done only in fiber optic channels. In WDM, several light waves from multiple sources are connected by using a prism to form a composite light signal sent across the medium.At the receiver end, the hybrid light is broken down into different light waves, and these are delivered to their corresponding receiver, as shown in the figure below. The concept of WDM and Frequency-Division Multiplexing (FDM) is the same.The application of WDM is the Synchronous Optical Network (SONET) in which various optical fiber lines are multiplexed and demultiplexed. There is a new technique known as ... Read More

Frequency-Division Multiplexing (FDM) is an analog method which is used when the channel's bandwidth is higher than the consolidated bandwidths of the signals which are to be broadcasted.In FDM, different frequencies are combined into a single composite signal and are transmitted on the channel. At the receiver end, the reverse phase is applied to get the individual frequencies back for working. The entire bandwidth of the channel is divided into logical channels, and each sending device is given with the possession of a logical channel.There is a gap between the frequencies of adjoining channels to avoid one channel's frequency with ... Read More

Multiplexing is an approach of broadcasting signals from multiple sources over an individual transmission medium for maximum use and storing its value. The electronic device that performs this function is called a multiplexer.The diagram given below shows a multiplexer that receives three input lines and deflects them to an individual output line.The three computers joined by these links are combined and then transmitted on the single channel of high bandwidth at the sender's end. A demultiplexer divides the data stream into three sub channels and passes data to three receivers at the receiver's end.Multiplexing is achieved using a device known ... Read More

The electromagnetic waves having frequencies from 300 GHz to 400 THz (wavelengths from 1mm to 770 nm) are referred to as infrared (IR) waves. IR uses line-of-sight propagation.Infrared light is a transmission channel whose features are necessarily different from those of the radio frequencies. A fundamental property of infrared light is that it cannot penetrate the walls. This represents that it can easily include it within a room.Another advantage of infrared communication is massive bandwidth which is available for use, but has not been exploited to its full extent.The major disadvantage is that the sun creates emission in the infrared ... Read More

TCP/IP signifies the transmission control protocol/Internet Protocol. It was created by the Defence Advanced Research Projects Agency (ARPA, later DARPA) in the late 1970s.It is a collection of communication protocol. Moreover, it involves collection and methods for managing packet transport, media access, session interaction, data transfer, email and terminal emulation.Advantages of TCP/IP ModelThe main advantages of TCP/IP are as follows −It is a broadly accepted model which can deploy effectively in all the practical networking issues.TCP / IP can also enable cross-platform communications among the heterogeneous networks.It supports connection-oriented reliable service. It defines that it maintains the transfer of data ... Read More

OSI represents Open System Interconnection. It was produced by the International Organization for Standardization (ISO) located in Geneva, Switzerland, and the consultative committee for international Telephone and Telegraph (CCITT).OSI was created to develop a frequent standard of network structure throughout the globe. It supports a general idea of inter-process communication so that any open system can technically connect with another accessible framework without any issues. OSI model is a seven-layered architecture model.Advantages of the OSI ModelThe advantages of the OSI Model are as follows −The OSI models clearly define the services, interfaces and protocols. It explains which layer's services are supported. ... Read More

This is the highest layer of the Open System Interconnection (OSI) architecture. The application program's layer view is a user-oriented layer that offers the services to the end-user of a web.A message to be transmitted across the web introduces the OSI model and then traverses down into the physical layer. This is followed by sending a line up to the physical layer of destination and then upwards up to the receiver end system's application layers.It offers services that support customer applications, including database creation, messages, and document transfer.There are famous application layer protocols are X.400 (Electronic Mail Protocol), X.500 (Directory ... Read More

The presentation layer changes the data from an application layer into the device native internal mathematical structure and encodes communicated information into a displayable output format.It executes the code changes, document compressions, security encryption, etc. It also defines the data as per the software/hardware environment of the hub. For instance, demonstrating UNIX structured data in windows.The link between the presentation layer and the application and session layer has been shown in the diagram below −It is concerned with the syntax of data.TranslationThe procedure in two frameworks are generally to exchange the data in the form of character strings, numbers etc. ... Read More

The session layer supports establishing, controlling, and eliminating a session or dialogue between the two end frameworks. It generates the session, handles the packets sent back and forth during the session and removes the session. The dialogue type/session type is also defined through half-duplex or full-duplex.The session layer also supports data synchronization and check pointing so that only the information transmitted after the point of failure should be retransmitted in the event of network failure.This layer also governs the dialogue between the two processes by deciding who can send and who can get at what point during the transmission.The session ... Read More

The transport layer is essential for the source to deliver a complete message. The network layer is answerable for the end-to-end delivery of single packets.The transport layer obtains the messages of self-assertive length from the session layer, and divides them into packets. It also endures them to the network layer for communication, and completely reassembles the destination's packets.The transport layer data is an order number in every packet and helps the order numbers to identify the lost packets. Additionally, it ensures that the messages are regenerated in the proper order.The functioning of the transport layer is depicted in the diagram ... Read More