A path through which information is transmitted from one place diverse is called communication sift. It is also known as as communication medium or link. Issues pair wire, coaxial cable, fiber optic cable, microwave, satellite some others. are examples of communication channels.
In a communication channel, data is transmitted in the form of signals (analog signal). The information transmission is measured in bandwidth. The bandwidth is actually higher if more signals can be transmitted. Actually, the bandwidth measures the amount of information that could be transmitted while using media at the given while. For analog signals, bandwidth is represented in hertz (Hz). It implies number of signals transmitted per fresh. For digital signals, it can be represented in bits per second (bps). Different transmission media have different bandwidths. The higher the bandwidth of the transmission media, the more details can be transmitted.
Types of Communication Channel:
The communication channel or media is divided into two kinds of.
1. Guided Media.
2. Unguided Media.
1. Guided Media:
In guided communication media, communication devices are directly related to each other via cables or physical media for transmission of web data. The data signals are bounded to a cabling papers. Therefore, guided media one other called bounded media. The guided media are usually used in LAN. The examples of guided or bounded media are:
Twisted pair wire.
Coaxial tv set.
Fiber optic cable.
Twisted Pair Cable: Twisted pair cable is one of the most frequently employed communication multimedia system. It is used in local area network (LAN) for data communication between different laptop computers. It is also within telephone lines to carry voice and data indicates.
A twisted pair cable consists within a pair of thin diameter copper cables. These wires are paid by insulating material (such as plastic). These pair of wires are twisted together to form a cable. The wires are twisted around additional to minimize (or reduce) interference using twisted pairs in the cable.
The data transmission speed through twisted pair cable is about 9600 bits per second in a distance of 100 mirielle. However, this transmission speed is under coaxial cable or optical fiber.
The twisted pair cable has reigned supreme communication channel for voice and data communication. Famous its me is reducing because today more reliable communication media are available such as coaxial cable, fiber optic cable microwave and satellite tv.
Coaxial Cable: Coaxial cable is also referred to as Coax. It carries signals of upper frequency ranges than twisted-pair cable. Coaxial cable involving a single solid copper wire, along with that is called the inner conductor.
Coaxial cable can be used for telephone lines for voice and data transmission with high frequency. The bandwidth of coaxial cable is 80 times as compared to that of twisted pair media. Coaxial cable is also widely use within local area network (LAN). It is far more expensive than twisted-pair wire.
Fiber-Optic Cable: In twisted-pair cable and coaxial cable, data is transmitted their form of electric frequencies. The fiber optic cable uses light to send out data. Information transmission speed is quite high (because fiber-optic cable uses light for you data). The info transmission speed is up to billions bits per second. Today, most of phoning companies and cable TV operators are selecting fiber optic cables inside networks.
A fiber optic cable consists of tubes of glass (or thin glass fibers) in which data is transmitted as pulses of sunshine. A typical optical fiber will be a very narrow strand or fiber of glass called each video. It is thinner than an individual hair. Each video is enclosed by a concentric layer of glass called Cladding. The diameter with a core is 62.5 microns (I micron = 10-6 meters). The diameter of cladding is about 125 microns. The cladding is coated with heat retaining material such as plastic, that's called the Jacket.
2. Unguided Media:
In unguided communication media, data is communicated between communication devices in the form of say. Unguided media provides in order to transmit data signals but does not guide them along some path. Info signals aren't bounded to a cabling newspaper and tv. Therefore,. unguided media is typically known as unbounded media.
This transmission medium is commonly employed when it's impossible to install the cables that. The data can be transmitted all around the world through this medium. The examples of unguided or unbounded media are:
Microwaves: In microwave transmission, data is transmitted through air or space, instead of through cables or cables that. Microwaves are high frequency radio waves. These waves may only travel in straight boundaries.
The data is transmitted and received any microwave station. A microwave station is also called relay station or the booster. A microwave station contains an antenna, transmitter, receiver, and also other equipments possess required for microwave indicator. Microwave antennas are placed close to high towers or buildings and are already placed within 20 to 30 miles of each other. There may be many microwave stations between the sender and receiver. Information is transmitted 1 microwave station to another. Each microwave station receives signals from previous microwave station and transmits to next station. In this particular way, stats are transmitted over larger kilometers.
The data transmission speed of microwave transmission is up to 150 Mb / s. Microwave transmission is used in environments where installing physical transmission media is impossible and where line-of-sight transmission is available, it is used in wide-open areas. Today, it is necessary by telephone companies, cable tv providers, universities etc.
Satellite Communication: A communication satellite is really a space location. It receives microwave signals (or messages) from earth options. Satellite transmission station that can send and receive messages is known as earth station. The earth based stations often are microwave stations. Other devices, such as PDAs and GPS receivers, also functions as earth based avenues.
Satellites rotate approximately 22,300 miles higher than the earth in precise shops. The communication satellite consists of solar powered, transceiver that receives and sends signals. The signals are transmitted 1 earth station to the satellite. The satellite receives and amplifies the signals and sends them various earth channel. This entire process takes just a few seconds. In this way, data or messages are transferred from one location to an alternative. Transmitting a signal from ground or earth station to a satellite station in space is called up-linking along with the reverse is called the down-linking. The data transmission speed of communication satellite is most high such as upto 1 Gbps.
Different communication satellites are employed to carry types information such as telephone calls, television transmissions, military communication, weather data, and even radio stations use them for televison broadcasting. The global positioning systems and Internet likewise use the communication satellites.
Radio Broadcast: It can be a wireless transmission medium which to communicate information through radio signals in air, over telephone long distance such as between cities and countries.
In this medium, a transmitter can be send messages (signals) and receiver needs to receive the company. To receive the radio signal, the receiver has an antenna that is located in the range of signal. Some networks use a special device called transceiver used to deliver and for messages through radio means. The data transmission speed of radio broadcast is down to 54 Megabyte per second.
Cellular Radio: Cellular radio is a kind radio broadcast that is commonly used for mobile communications such as cellular telephones and wireless modems. A cellular, telephone is a mobile phone device that uses high frequency radio waves to transmit voice and digital voicemails. Some mobile users connect their own laptop computer an additional mobile devices to a cellular telephone to access the Web, send and receive e-mail etc. while away from a standard phone line.