100BASE-T4 is the early implementation of Fast Ethernet over twisted pair cables, carrying data traffic at 100 Mbps (Mega bits per second) in local area networks (LAN). It was launched as the IEEE 802.3u standard in 1995. Here, 100 is the maximum throughput, i.e. 100 Mbps, BASE denoted use of baseband transmission, and T4 denotes use of four twisted pair cables in Fast Ethernet.PropertiesThis has four pairs of unshielded twisted pair of Category 3. i.e. voice grade.Two of these pairs are bi-directional and the other two are unidirectional. The two unidirectional wires are reserved for receiving and sending data respectively. ... Read More

100BASE-FX is the technical name of Fast Ethernet over fiber optic cables. It is a version of Fast Ethernet carrying data traffic at 100 Mbps (Mega bits per second) in local area networks (LAN). It was launched as the IEEE 802.3u standard in 1995. Here, 100 is the maximum throughput, i.e. 100 Mbps, BASE denoted use of baseband transmission, and FX denotes use of optical fibers in Fast Ethernet.The 100BASE-FX Physical Medium Dependent (PMD) sublayer is defined by Fiber Distributed Data Interface (FDDI).PropertiesThis has two pairs of optical fibers. One pair transmits frames from hub to the device and the ... Read More

100BASE-TX is the technical name of Fast Ethernet over twisted pair cables. It is a predominant form of Fast Ethernet carrying data traffic at 100 Mbps (Mega bits per second) in local area networks (LAN). It was launched as the IEEE 802.3u standard in 1995. Here, 100 is the maximum throughput, i.e. 100 Mbps, BASE denoted use of baseband transmission, and TX denotes use of twisted pair cables in Fast Ethernet.PropertiesThis has either two pairs of unshielded twisted pairs (UTP) category 5 wires or two shielded twisted pairs (STP) type 1 wires.One of these pairs transmits frames from hub to ... Read More

In computer networks, Fast Ethernet is a variation of Ethernet standards that carry data traffic at 100 Mbps (Mega bits per second) in local area networks (LAN). It was launched as the IEEE 802.3u standard in 1995, and stayed the fastest network till the introduction of Gigabit Ethernet.Fast Ethernet is popularly named as 100-BASE-X. Here, 100 is the maximum throughput, i.e. 100 Mbps, BASE denoted use of baseband transmission, and X is the type of medium used, which is TX or FX.Varieties of Fast EthernetThe common varieties of fast Ethernet are 100-Base-TX, 100-BASE-FX and 100-Base-T4.100-Base-T4This has four pairs of UTP ... Read More

HubsA hub is a physical layer networking device which is used to connect multiple devices in a network. They are generally used to connect computers in a LAN.A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination or not.SwitchesA switch is a data link layer networking device which connects devices in a network and uses packet switching to send and ... Read More

ModulationModulation is the process of transforming a carrier signal so that it can carry the information of a message signal. It superimposes the contents of the message signal over a high-frequency carrier signal, which is then transmitted over communication channels.Modulation can be of two types −Analog ModulationDigital ModulationAnalog ModulationHere, the analog information signal is transformed to the analog carrier signal so that it can travel large distances without substantial loss.Analog modulation can be of three types −Amplitude ModulationFrequency ModulationPhase ModulationDigital ModulationDigital modulation is the process of converting a digital bit stream into an analog carrier wave for transmission via a ... Read More

Power line communications (PLC) allows data communications over conductors that are simultaneously used for transmission of electrical power.PLCs work by adding a modulated carrier signal, formed by superimposing data signal over low frequency power signal. Electrical signals transmit at 50 – 60 Hz, while the data signals transmit in the order of MHz.PLCs are also known as power line carrier, power line digital subscriber line (PDSL), or power line networking (PLN).Types of PLC:Narrowband PLC: They work at lower frequencies of 3-500KHz. Their data rates are low but have high range of several kilometres. They are used in the Smart Grid.Broadband ... Read More

Data rate refers to the speed of data transfer through a channel. It is generally computed in bits per second (bps). Higher data rates are expressed as Kbps ("Kilo" bits per second, i.e.1000 bps), Mbps ("Mega" bits per second, i.e.1000 Kbps), Gbps ("Giga" bits per second, i.e. 1000 Mbps) and Tbps ("Tera" bits per second, i.e. 1000 Gbps).One of the main objectives of data communications is to increase the data rate. There are three factors that determine the data rate of a channel:Bandwidth of the channelNumber of levels of signals that are usedNoise present in the channelData rate can be ... Read More

Fourier analysis is a method of representing general functions by approximate sum of simple trigonometric functions. The method is named after mathematician Jean Baptiste Joseph Fourier who formulated and proved the Fourier series. Fourier analysis is used in electronics, communications and acoustics.The Fourier series decomposes a periodic function as a sum of sine and cosine components as expressed below:where, g(t) is the periodic functionT is the time periodf is the fundamental frequency expressed as 1/Tan is the sine amplitude of the nth harmonicbn is the cosine amplitude of the nth harmonicc is a constantThe values of an, bn and c ... Read More

Asymptotic AnalysisUsing asymptotic analysis, we can get an idea about the performance of the algorithm based on the input size. We should not calculate the exact running time, but we should find the relation between the running time and the input size. We should follow the running time when the size of input is increased.For the space complexity, our goal is to get the relation or function that how much space in the main memory is occupied to complete the algorithm.Asymptotic BehaviorFor a function f(n) the asymptotic behavior is the growth of f(n) as n gets large. Small input values ... Read More