CSE Corner

Document Free Discussion AM FM AM stands for Amplitude Modulation FM stands for Frequency Modulation In AM, a radio wave known as the "carrier" or "carrier wave" is modulated in amplitude by the signal that is to be transmitted In FM, a radio wave known as the "carrier" or "carrier wave" is modulated in frequency by the signal that is to be transmitted. The frequency and phase remain the same. The amplitude and phase remain the same. AM has poorer sound quality compared with FM, but is cheaper and can be transmitted over long distances. It has a lower bandwidth so it can have more stations available in any frequency range. FM is less prone to interference than AM. However, FM signals are impacted by physical barriers. FM...

Document Free Discussion Synchronous TDM Statistical TDM In Synchronous TDM data flow of each input connection is divided into units and each input occupies one output time slot. In Statistical TDM slots are allotted dynamically. i.e. input line is given slots in output frame if and only if it has data to send. In Synchronous TDM no. of slots in each frame are equal to no. of input lines. In Statistical TDM, No. of slots in each frame are less than the no. of input lines. Buffering is not done, frame is sent after a particular interval of time whether someone has data to send or not. Buffering is done and only those inputs are given slots in output frame whose buffer contains data to send. Synchronization bits are used at the beginning of each fr...

* A digital switch is a hardware device for handling digital signals. The main function of these switches is to manage digital signals generated or passed through a telephone exchange and then forward it to the telephone company's back-end network. Quotes: "Life without faith in something is too narrow a space to live." ~George L Spaulding || "The most common way people give up their power is by thinking they don't have any." ~Alice Walker || "Happy are those who dream dreams and are ready to pay the price to make them come true." ~Leo Suenens

* Time Division Switching In time division switching, sampled values of speech signals are transferred at fixed intervals. The time division switching may be analog or digital. Time division switching involves the sharing of crosspoints for shorter periods of time. This paves way for the re-assign of crosspoints and its associated circuits for other needed connections. Therefore, in time division switching, greater savings in crosspoints can be achieved. Hence, by using a dynamic control mechanisms, a switching element can be assigned to many inlet-outlet pairs for few microseconds. This is the principle of time division switching. Space Division Switching In space division switching, a dedicated path is established between the calling and the called subscribers for the...

Free Discussion In virtual circuit packet switching, a single route is choosen between the sender and receiver and all the packets are sent through this route . Every packet contains the virtual circuit number. As in circuit switching virtual circuit needs call set up before the actual transmission can be started. The routing is based on the virtual circuit number. A virtual circuit Network is normally implemented in the data link layer. While a circuit switched Network is implemented in the physical layer and Datagram Network in the network layer. Quote: "My mission in life is not merely to survive, but to thrive; and to do so with some passion, some compassion, some humor, and some style..."

Free Discussion 3 Multiplexing techniques are common for fiber optic link.those are: Wavelength Division Multiplexing Optic Time Division Multiplexing Space Division Multiplexing Wavelength Division Multiplexing : In fiber-optic communications, wavelength-division multiplexing is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths of laser light. This technique enables bi-directional communications over one strand of fiber, as well as multiplication of capacity. Optic Time Division Multiplexing: Optical Time Division Multiplexing is a multiplexing technique that,which basically multiplexes a number of low bit rate optical channels in time domain. Several low speed optical channel are multiplexed into a fixed electrical clock period,thus increasing the transmission speed. Each signal is transmitted over a single communication channel...

Document Free Discussion Circuit Switching Packet Switching Circuit Switching is Connection oriented. Packet Switching Connectionless Data transmission takes place,after the circuit is established for the duration of the transmission. Dynamic route is established for each packet which carries the route information It follows a uniform path throughout the session There is no end to end reservation of links Circuit Switching is implemented at Physical Layer Packet Switching is implemented at Network Layer Circuit switching is ideal for voice communication Packet switching is mainly used for data and voice communication and the delay is not uniform ...

Free Discussion Switching network : Switching is the process of forwarding packets coming in from one port to a port leading towards the destination. When data comes to a port it is called Engress and when data leaves a port it is called Egress . A communication system may include number of switches and nodes. Circuit Switching : In circuit switching,A dedicated channel is set up for a single connection between the sender and receiver during the communication session. In telephone communication system,the normal voice call is the example of circuit switching. The telephone service provider maintain a unbroken link for each telephone call. Circuit Switching is pass through 3 phases,those are: Circuit Establishment Data Transfer Circuit Disconnect Packet Switching : Packet switching is a method of grouping data which...

Free Discussion Time Division Multiplexing Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern. Frequency Division Multiplexing Frequency Division Multiplexing (FDM) is a networking technique in which multiple data signals are combined for simultaneous transmission via a shared communication medium. FDM uses a carrier signal at a discrete frequency for each data stream and then combines many modulated signals. Quote: “There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.” ...

Document Free Discussion TDM FDM TDM stands for time division multiplexing FDM stands for frequency division multiplexing In TDM,Times scale is shared. In FDM,Frequency is shared. TDM is preferred for Digital signals and analog signals FDM is preferred for just Analog signals Interference is Low or negligible Interference is High The Circuitry of TDM is Simpler The Circuitry of FDM is Complex It can be used Efficiently It is Ineffective. Synchronization is required Synchronization is not required Quote: “Happiness is letting go of what you think your life is ...

Multiplexing is a popular networking technique that integrates multiple analog and digital signals into a signal transmitted over a shared medium. Multiplexers and de-multiplexers are used to convert multiple signals into one signal.Actually, Multiplexing is a technique through which several signals are concurrently transmitted over a single data link. Different types of multiplexing techniques: Frequency Division Multiplexing Time division Multiplexing Wave length Division Multiplexing Code Division Multiplexing Quote: Don’t forget you’re human. It’s okay to have a meltdown. Just don’t unpack and live there. Cry it out. Then refocus on where you’re headed”

Quote: “Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.” ― Albert Einstein || “You only live once, but if you do it right, once is enough.” ― Mae West

Frequency Shift Keying(FSK) : The short form of Frequency Shift Keying is referred as FSK. It is a digital modulation technique which shifts the frequency of the carrier with respect to binary data signal. The FSK modulation technique uses two different carrier frequencies to represent binary 1 and binary 0. Advantages of FSK : It has lower probability of error It provides high SNR (Signal to Noise Ratio). It has higher immunity to noise due to constant envelope. Hence it is robust against variation in attenuation through channel. FSK transmitter and FSK receiver implementations are simple for low data rate application. Disadvantages of FSK : ...

Amplitude Shift Keying(ASK) : The short form of Amplitude Shift Keying is referred as ASK.It is the digital modulation technique.Amplitude Shift Keying (ASK) is a type of Amplitude Modulation which represents the binary data in the form of variations in the amplitude of a signal. Any modulated signal has a high frequency carrier. The binary signal when ASK modulated, gives a zero value for Low input while it gives the carrier output for High input. Advantages of ASK : It offers high bandwidth efficiency. It has simple receiver design. ASK modulation can be used to transmit digital data over optical fiver. ASK modulation and ASK de-mo...

Data Encoding : In computers, encoding is the process of putting a sequence of characters (letters, numbers, punctuation, and certain symbols) into a specialized format for efficient transmission or storage. Decoding is the opposite process -- the conversion of an encoded format back into the original sequence of characters. Encoding and decoding are used in data communications, networking, and storage. The data encoding technique is divided into following types,depending upon the type of data conversion. Analog data to Analog signals : The modulation techniques such as Amplitude Modulation,Frequency Modulation, Phase Modulation of analog signals fall under this category. Analog data to Digital signals ...

* Amplitude Modulation : Amplitude modulation is a modulation technique where the amplitude of a carrier varies depending on the information signal.It is the most common method of broadcasting radio signals. AM radio broadcast signals use lower carrier frequencies, this helps them to travel longer distances. Sometimes, AM signals can be able to bounce off the ionosphere. The distance travelled by the AM is much larger than the FM. Has poor sound quality, but can transmit longer distance. Frequency Modulation : In this module, the frequency of the carrier wave is modified according to the signal that carries information. The radio signals have large bandwidth than AM radio signals, which helps to offer much better sound quality. It also enables to transmit stereo signals.Has higher bandwidth with better sound quality. The equipment requirements...

Analog Signal : An analog signal is a continuous signal which contains time-varying quantities. Unlike a digital signal, which has a discrete value at each sampling point, an analog signal has constant fluctuations.The illustration below shows an analog pattern (represented as the curve) alongside a digital pattern (represented as the discrete lines). An analog signal can be used to measure changes in some physical phenomena such as light, sound, pressure, or temperature. For instance, an analog microphone can convert sound waves into an analog signal. Even in digital devices, there is typically some analog component that is used to take in information from the external world, which will then get translated into digital form (using an analog-to-digital converter). Digital Signal : A digital s...

The light in a fiber-optic cable travels through the core by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances. Quote: Where there is a will, there is a way. If there is a chance in a million that you can do something, anything, to keep what you want from ending, do it. Pry the door open or, if need be, wedge your foot in that door and keep it open.|| Your time is limited, so DON'T WASTE IT LIVING SOMEONE ELSE'S LIFE...|| The road to your dreams isn’t always easy to navigate, sometimes dotted with mountains to climb, obstacles to overcome—and hard, mind-numbing ...

An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network, that uses the Internet Protocol for communication. An IP address, or simply an "IP," is a unique address that identifies a device on the Internet or a local network. It allows a system to be recognized by other systems connected via the Internet protocol. There are two primary types of IP address formats used today — IPv4 and IPv6 Quote: Where there is a will, there is a way. If there is a chance in a million that you can do something, anything, to keep what you want from ending, do it. Pry the door open or, if need be, wedge your foot in that door and keep it open.|| Your time is limited, so DON'T WASTE IT LIVING SOMEO...

Chapter - 1+2 (Introduction + Data transmission ) What is data communication? Describe simplified data communication model with proper diagram. What is protocol? Describe key elements of protocol. Difference between connection oriented and connectionless protocol. Describe OSI model and TCP/IP protocol. Difference between 3types of transmission mode. Difference between ---- Port Address/Logical address/Physical Address. What is IP address?Calculate subnet mask of IPV4. Frame Relay,X.25 Protocol standard,LAN/WAN. ...