A path in which information is transmitted from one place to these guys called communication channel. It can also be called communication medium or link. The twisted pair wire, coaxial cable, fiber optic cable, microwave, satellite etc. are samples of communication channels.
In a communication channel, data is transmitted available as signals (analog signal). The data transmission is measured in bandwidth. The bandwidth is going to be higher if more signals can be transmitted. Actually, the bandwidth measures the amount of information that may be transmitted from the media within the given time frame. For analog signals, bandwidth is represented in hertz (Hz). It means number of signals transmitted per second. For digital signals, it can be represented in bits per second (bps). Different transmission media have different bandwidths. The higher the bandwidth in the transmission media, the greater information could be transmitted.
Types of Communication Channel:
The communication channel or media is divided into two sorts.
In guided communication media, communication devices are directly related to the other via cables or physical media for transmission of information. The data signals are bounded to a cabling media. Therefore, guided media can also be called bounded media. The guided media are usually found in LAN. The types of guided or bounded media are:
Twisted Pair Cable: Twisted pair cable is one in the mostly used communication media.
It is found in local area network (LAN) for data communication between different computers. It is additionally used in telephone lines to carry voice and data signals.
A twisted pair cable is made up of couple of thin diameter copper wires. These wires are covered by padding (such as plastic). These set of two wires are twisted together to form a cable. The wires are twisted around one another to attenuate (or reduce) interference off their twisted pairs in the cable. Undeniably RJ45 Strain Relief Boots online?
The data transmission speed through twisted pair cable is all about 9600 bits per second in the distance of 100 meters. However, this transmission speed is under coaxial cable or optical fiber.
The twisted pair cable may be the typical communication channel for voice and data communication. But now its use is reducing because today more reliable communication media can be purchased like coaxial cable, fiber optic cable microwave and satellite.
Coaxial Cable: Coaxial cable can be referred to as Coax. It carries signals of higher frequency ranges than twisted-pair cable. Coaxial cable includes a single solid copper wire, which is sometimes called the inner conductor.
Coaxial cable may be used for telephone lines for voice and data transmission with quite high frequency. The bandwidth of coaxial cable is 80 times in excess of those of twisted pair media. Coaxial cable can be widely used in local area network (LAN). It is higher priced than twisted-pair wire.
Fiber-Optic Cable: In twisted-pair cable and coaxial cable, details are transmitted by means of electric frequencies. The fiber optic cable uses light for you data. The data transmission speed is extremely high (because fiber-optic cable uses light to deliver data). The data transmission speed is up to billions bits per second. Today, most with the telephone companies and cable TV operators are employing fiber optic cables inside their networks.
A fiber optic cable includes tubes of glass (or thin glass fibers) whereby details are transmitted as pulses of light. A typical optical fiber is made up of very narrow strand or fiber of glass referred to as the core. It is thinner than a real human hair. The core is in the middle of a concentric layer of glass called Cladding. The diameter of an core is 62.5 microns (I micron = 10-6 meters). The diameter of cladding is around 125 microns. The cladding is coated with efficiency including plastic, which is sometimes called the Jacket.
2. Unguided Media:
In unguided communication media, info is communicated between communication devices by means of wave. Unguided media provides means to deliver data signals but does not guide them along a certain path. The data signals aren’t bounded to your cabling media. Therefore,. unguided media can also be called unbounded media.
This transmission medium can be used when it really is impossible to setup the cables. The data might be transmitted around the globe through this medium. The instances of unguided or unbounded media are:
Microwaves: In microwave transmission, info is transmitted through air or space, rather than through cables or wires. Microwaves are high frequency radio waves. These waves can only travel in straight lines.
The details are transmitted and received through a microwave station. A microwave station can also be called relay station or booster. A microwave station contains an antenna, transmitter, receiver, and other equipments which might be necessary for microwave transmission. Microwave antennas they fit around the high towers or buildings and these are put within 20 to 30 miles of the other. There may be many microwave stations involving the sender and receiver. Data is transmitted from microwave station to another. Each microwave station receives signals from previous microwave station and transmits to next station. In this way, information is transmitted over larger distances.
The data transmission speed of microwave transmission is up to 150 Mbps. Microwave transmission is found in environments where installing physical transmission media is not possible and where line-of-sight transmission is available, it really is utilized in wide-open areas. Today, it really is utilised by telephone companies, cable providers, universities etc.
Satellite Communication: A communication satellite is often a space station. It receives microwave signals (or messages) from earth stations. Satellite transmission station that could send and receive messages is recognized as earth station. The earth based stations often are microwave stations. Other devices, including PDAs and GPS receivers, also functions as earth based stations.
Satellites rotate approximately 22,300 miles across the earth in precise locations. The communication satellite is made up of solar powered, transceiver that receives and sends signals. The signals are transmitted from earth station to the satellite. The satellite receives and amplifies the signals and sends them to a new earth station. This entire process takes just a few seconds. In this way, data or messages are transferred from one location to another. Transmitting an indication from ground or earth station to some satellite station in space is termed up-linking as well as the reverse is known as the down-linking. The data transmission speed of communication satellite is high including upto 1 Gbps.
Different communication satellites are used to hold different varieties of information such as phone calls, television transmissions, military communication, weather data, and even radio stations use them for broadcasting. The global positioning systems and Internet also use the communication satellites.
Radio Broadcast: It is really a wireless transmission medium that can be used to talk information through radio signals in air, over international calls including between cities and countries.
In this medium, a transmitter is required to send messages (signals) and receiver is required to receive them. To receive radio stations signal, the receiver comes with a antenna that’s located in the selection of signal. Some networks use a special device called transceiver utilized to send and receive messages as radio signals. The data transmission speed of radio broadcast is up to 54 Mbps.
Cellular Radio: Cellular radio can be a type of radio broadcast that is employed for mobile communications including cellular telephones and wireless modems. A cellular, telephone is often a telephone device which utilizes high frequency radio waves to transmit voice and digital messages. Some mobile users connect their laptop computer and other mobile devices to a cellular telephone to gain access to the Web, send and receive e-mail etc. while far from an ordinary telephone line.