by Dinesh Thakur Category: Communication Networks

The pair of twisted is the simplest transmission medium. it consists of one or more pairs of electrical son arranged spiral. This type of support is suitable for transmission both analog and digital.

 
by Dinesh Thakur Category: Communication Networks

There are two different approaches for the transmission of digital signals: baseband transmission and broadband transmission.

Baseband transmission

Baseband transmission means sending a digital signal over a channel without changing the digital signal to an analog signal.

 
by Dinesh Thakur Category: Communication Networks

Computers are digital in nature. Computers process, store, and communicate information in binary form, i.e. in the combination of 1s and 0s which has specific meaning in computer language. A binary digit (bit) is an individual 1 or O. Multiple bit streams are used in a computer network.



 
by Dinesh Thakur Category: Communication Networks

Analog is best explained by the transmission of signal such as sound or human speech, over an electrified copper wire. In its native form, human speech is an oscillatory disturbance in the air. Which varies in terms of its volume or power (amplitude) and its pitch or tone (frequency)? Analogous variations in electrical or radio waves are created in order to transmit the analog information signal for video or audio or both over a network from a transmitter (TV station or CATV source) to a receiver (TV set, computer connected with antenna). At the receiving end an approximation (analog) of the original information is presented.



 
by Dinesh Thakur Category: Communication Networks

Definition Data Transmission: When we enter data into the computer via keyboard, each keyed element is encoded by the electronics within the keyboard into an equivalent binary coded pattern, using one of the standard coding schemes that are used for the interchange of information. To represent all characters of the keyboard, a unique pattern of 7 or 8 bits in size is used. The use of 7 bits means that 128 different elements can be represented, while 8 bits can represent 256 elements. A similar procedure is followed at the receiver that decodes every received binary pattern into the corresponding character.



 
by Dinesh Thakur Category: Communication Networks

Data communication refers to the exchange of data between a source and a receiver via form of transmission media such as a wire cable. Data communication is said to be local if communicating devices are in the same building or a similarly restricted geographical area.

 
by Dinesh Thakur Category: Communication Networks

Open System Interconnection (OSI) model, an ISO standard for worldwide communication Networks that defines a networking framework for implementing protocols in seven layers. Layering the communications process means breaking down the communication process into Smaller and Easier to handle interdependent categories. The convention and rules used in such communications are collectively known as Layer protocolOpen Systems Interconnection (OSI) model is developed by ISO (International organization for standardization) in 1984. ISO is the organization dedicated to defining global communication and standards.



 
by Dinesh Thakur Category: Communication Networks

Transmission media is a pathway that carries the information from sender to receiver. We use different types of cables or waves to transmit data. Data is transmitted normally through electrical or electromagnetic signals.



 
by Dinesh Thakur Category: Communication Networks

Unbound transmission media extend beyond the limiting confines of cabling. They provide an excellent Communication Networks alternative for WANS. The lack of physical restrictions provides larger bandwidth as well as wide area capabilities. Unbound media typically operate at very high frequencies. The three types of unbound transmission media are: Radio wave, Micro wave, Infrared.



 
by Dinesh Thakur Category: Communication Networks

Bound Transmission Media in Communication Networks are the cables that are tangible or have physical existence and are limited by the physical geography. Also known as Conducted systems, wired media generally employ a metallic or glass conductor which serves to conduct, some form of electromagnetic energy.

 
by Dinesh Thakur Category: Communication Networks

The first layer (physical layer) of Communication Networks the OSI Seven layer model is dedicated to the transmission media. Due to the variety of transmission media and network wiring methods, selecting the most appropriate media can be confusing - what is the optimal cost-effective solution. When choosing the transmission media, what are the factors to be considered?

 
by Dinesh Thakur Category: Communication Networks

Unshielded Twisted Pair (UTP) : UTP is the copper media, inherited from telephony, which is being used for increasingly higher data rates, and is rapidly becoming the de facto standard for horizontal wiring, the connection between, and including, the outlet and the termination in the communication closet.

 
by Dinesh Thakur Category: Communication Networks

Definition: Optical fiber consists of thin glass fibres or plastic or any dielectric medium which can carry light signals from one end to the other. Optical fiber refers to the medium and the technology which is related, or you can say that it is connected with the transmission of information in the form of light impulses and this transmission is done along with a glass or plastic wire or fiber. The wires of fiber optic cable can carry much more information than any other conventional copper wire. The typical optical fiber consists of a very narrow strand of glass called the core. Around the core is a concentric layer of glass called the cladding.
Optical fibres make use of light to send information through the optical medium.



 
by Dinesh Thakur Category: Communication Networks

Data link layer is the second layer in OSI reference model and lies above the physical layer. The data link layer performs the following functions.

1. Data link layer receives the data from the network layer & divide it into manageable units called frames.

 
by Dinesh Thakur Category: Communication Networks

Hubs/Repeaters are used to connect together two or more network segments of any media type. In larger design, signal quality begins to deteriorate as segment exceeds their maximum length. A hub provides the signal amplification required to allow a segment to be extended a greater distance.

 
by Dinesh Thakur Category: Communication Networks

The term Transmission Mode defines the direction of the flow of information between two communication devices i.e. it tells the direction of signal flow between the two devices.

There are three ways or modes of data transmission: Simplex, Half duplex (HDX), Full duplex (FDX)



 
by Dinesh Thakur Category: Communication Networks

Congestion is an important issue that can arise in packet switched network. Congestion is a situation in Communication Networks in which too many packets are present in a part of the subnet, performance degrades. Congestion in a network may occur when the load on the network (i.e. the number of packets sent to the network) is greater than the capacity of the network (i.e. the number of packets a network can handle.). Network congestion occurs in case of traffic overloading.

 
by Dinesh Thakur Category: Communication Networks

In Communication Networks External electromagnetic signals can cause incorrect delivery of data. By this, data in the communication Networks can be received incorrectly, data can be lost or unwanted Communication Networks data can be generated. Any of these problems are called transmission errors in communication networks.

 
by Dinesh Thakur Category: Communication Networks

Error detection and correction has great practical importance in maintaining data (information) integrity across noisy Communication Networks channels and lessthan- reliable storage media.



 
by Dinesh Thakur Category: Communication Networks

The Media Access Control (MAC) data communication Networks protocol sub-layer, also known as the Medium Access Control, is a sub-layer of the data link layer specified in the seven-layer OSI model. The medium access layer was made necessary by systems that share a common communications medium. Typically these are local area networks. The MAC layer is the "low" part of the second OSI layer, the layer of the "data link". In fact, the IEEE divided this layer into two layers "above" is the control layer the logical connection (Logical Link Control, LLC) and "down" the control layer The medium access (MAC).



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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