In transmission media is the way the systems are connected to route data signals in a network.The telecommunication links are classified into two categories −Guided media (wired)Unguided media (wireless).Both guided and unguided are used for short distance (LANs, MANs) as well as long distance (WANs) communication.Let us discuss Guided transmission media.Guided transmission mediaGuided transmission media consists of physical connection between source and destination through a wire or a cable.There are three basic types of guided media which are as follows −Twisted pair cableCo-axial cableFiber-optic cableTwisted Pair CopperStep 1 − It is the most used media across the world. All the ... Read More

Transmission impairment occurs when the received signal is different from the transmitted signal. As we know, a signal can be transmitted as Analog signal or it can be transmitted as a digital signal.In Analog signals due to transmission impairment the resulting received signal gets different amplitude or the shape. In the case of digitally transmitted signals at the receiver side we get changes in bits (0's or 1's).CausesThere are various causes of transmission impairments, which are as follows −NoiseDelay DistortionAttenuation DistortionLet us discuss noise which is one of the causes for transmission impairments.NoiseNoise is the major factor for the transmission ... Read More

Transmission impairment occurs when the received signal is different from the transmitted signal. As we know, a signal can be transmitted as Analog signal or it can be transmitted as a digital signal.In Analog signals due to transmission impairment the resulting received signal gets different amplitude or the shape. In the case of digitally transmitted signals at the receiver side we get changes in bits (0's or 1's).CausesThere are various causes of transmission impairments, which are as follows −NoiseDelay DistortionAttenuation DistortionLet us discuss Delay Distortion.Delay DistortionThis kind of distortion is mainly appearing in case of composite signals in which a ... Read More

Transmission impairment occurs when the received signal is different from the transmitted signal. As we know, a signal can be transmitted as Analog signal or it can be transmitted as a digital signal.In Analog signals due to transmission impairment the resulting received signal gets different amplitude or the shape. In the case of digitally transmitted signals at the receiver side we get changes in bits (0's or 1's).CausesThere are various causes of transmission impairments, which are as follows −NoiseDelay DistortionAttenuation DistortionLet us discuss Attenuation Distortion.Attenuation DistortionAttenuation is generally decreased in signal strength, by which the received signal will be difficult ... Read More

The real function of every layer in OSI is to provide services to the layer above it.Network Services TerminologyThe network services terminology is explained below −Entities − In each layer there are so many active elements. An entity can be a software entity or a hardware entity. For example, a software entity is Process and a hardware entity is Intelligent I/O chipPeer Entities − Entities in the same layer on different machines are called peer entities.Service Provider and Service User − The entities in layer N-1 implement a service used by layer N. Layer N-1 is called the Service Provider ... Read More

BISDN is an extension of ISDN, that is, it has narrowband capability of ISDN but also the broadband capability.The purpose of BISDN is to achieve complete integration of services, ranging from low-bit- rate burst signals to high-bit-rate continuous real-time signals.B-ISDN ServicesThere are two types of B-ISDN services which are as follows −Interactive Services − Two-way exchange of information (other than control signalling information) between two subscribers or between a subscriber and a service provider.Distribution Services − Primarily one way transfer of information, from service provider to B-ISDN subscriber.These services are shown in the diagram format below −Technology DevelopmentsThe key technology ... Read More

Transmission impairment occurs when the received signal is different from the transmitted signal. As we know, a signal can be transmitted as Analog signal or it can be transmitted as a digital signal.In Analog signals due to transmission impairment the resulting received signal gets different amplitude or the shape. In the case of digitally transmitted signals at the receiver side we get changes in bits (0's or 1's).CausesThere are various causes of transmission impairments −NoiseDistortionAttenuationLet us understand them one by one.NoiseNoise is the major factor for the transmission distortion as any unwanted signal gets added to the transmitted signal by ... Read More

ISDN is also known as Integrated Services Digital Network. It is helpful in a wide range of services, for example, text (message), image, etc. It is capable of giving services and the foundation of telecommunication networks i.e. useful in the framework.It was also known as Integrated Digital Network because it is a digital technique that is used in switching as well as in transmission.Types of ChannelIt has three types of Channel.B-channelData-rate: 64 kbps.Required: for voice, information which has less data rate.D-channelData-rate: 16-64 kbps.Required: for packet switched data.H-channelData-rate − 1536 kbps or 1920 kbps data rate.Required − for video/ high-speed data ... Read More

The physical layer’s major function is to move data in the form of electromagnetic signals over a transmission medium. The data which is used by a person is not in a form that can be transmitted over a network.For example, a photograph has to be changed to a form that transmission media can accept. Transmission media works by conducting energy along a physical path.Both data and the signals that represent them can be either Analog or digital in form.Analog DataAnalog data refers to information which is continuous.For Example, an Analog clock which is having hour, minute, and second hands that ... Read More

Dense wavelength division multiplexing (DWDM) is a technology that multiplexes data signals from different sources so they can share a single optical fibre pair while maintaining complete separation of the data streams.DWDM can handle higher speed protocols up to 100 Gbps per channel. Each channel is only 0.8nm apart. Dense wavelength division multiplexing works on the same principle as CWDM but in addition to the increased channel capacity it can also be amplified to support much longer distances.The diagram given below represents the dense wavelength division multiplexing (DWDM) −Working of DWDMThe working of DWDM is explained below −DWDM modulates multiple ... Read More