Components Of A Network: Transmission Media PDF

TRANSMISSION MEDIA Data and information is transmitted using transmission media. These are sometimes referred to as communication medias. Transmission media is simply the means through which data is transferred from one place/device to another. Transmission media is the physical material which data...

TRANSMISSION MEDIA Data and information is transmitted using transmission media. These are sometimes referred to as communication medias. Transmission media is simply the means through which data is transferred from one place/device to another. Transmission media is the physical material which data travels from one point to another. The type of transmission media that is used is dependent on the volume (amount) and distance of the information. Presented by: Ms Johnson 02/11/2021 2  There are two main categories of transmission medias: 1. Cabled/guided/wired 2. Wireless/unguided Presented by: Ms Johnson 02/11/2021 3 1. Cabled/guided/wired network- uses a wired medium such as twisted pair cable, optical fibre cable and coaxial cable to transfer data between connected devices. 2. Wireless/unguided- uses radio waves instead of physical cables as the transmission media. Presented by: Ms Johnson 02/11/2021 4  Transmission Media Wired Wireless Twisted Pair Fibre Optic Coaxial Cable Microwave Satellite Infrared Cable Cable Presented by: Ms Johnson 02/11/2021 5  TWISTED PAIR CABLES A voiceband channel can transmit data at a rate of 300 bits per second (bps) to 9600 bps. Twisted pair: The most popular form of transmitting data is telephone lines. This is easy to handle and cheap, but relatively slow. You need a modem to do this, since telephone lines are built to handle analogy data and not the digital data found in computers. Twisted pair wires are used for this form of data transmission. Unshielded twisted pair (UTP) is common in telephones and is most popular and generally the best option for school networks. These cable have pairs of insulated copper wires twisted round each other to help eliminate interference from adjacent pairs and other electrical devices. Twisted pair cable consists of pairs of Insulated wires twisted together. A telephone line consist of a twisted pair of copper wired and is the medium through which data travels. There are two types of twisted pair cable: shielded twisted pair (STP) and unshielded twisted pair (UTP). Twisted pair cables are used for voice and data through telephone lines, digital subscriber line (DSL) and local area networks (LAN) in close proximatety Presented by: Ms Johnson 02/11/2021 7  TWISTED PAIR CABLES Presented by: Ms Johnson 02/11/2021 8  Advantages & Disadvantages of Twisted Pair Cables Advantages Disadvantage  Cheap  May be affected by physical  Easy to install conditions (interference)  Easy to replace 9 Presented by: Ms Johnson 02/11/2021 Optical fibre consists of thin glass fibres that can carry information at frequencies in the visible light spectrum and beyond. Fibre optic cable can transmit signals over much longer distance than coaxial or twisted pair cables. Fibre optic is used in most networks today such as cable and telephone, cabled television. Presented by: Ms Johnson 02/11/2021 10  FIBER OPTIC Presented by: Ms Johnson 02/11/2021 11  Advantages & Disadvantages of Fibre Optic Cables Advantages Disadvantages  Light weight  Expensive  Transfer large volume of data (the  Installation & maintenance expertise entire bible in one second) required  Resistance to corrosive materials  Transmit at a fast speed  It has also made it standard for connecting networks between buildings, as it not affected by moisture and lightning. 12 Presented by: Ms Johnson 02/11/2021 Coaxial cable consists of a single copper wire surrounded by at least three layers 1. An insulating material 2. A woven or braided metal 3. Plastic outer coating Coaxial cable is used in cabled networks, digital telephone networks, LAN’s that are in large institutions, etc. Presented by: Ms Johnson 02/11/2021 13  COAXIAL CABLES Presented by: Ms Johnson 02/11/2021 14  Advantages & Disadvantages of Coaxial Cables Advantages Disadvantages  Less vulnerable to interference  Cables are heavy and bulky  Can accommodate digital and analog  difficult to install since the cable is data somewhat rigid.  Transmit information faster than twisted pair cables 15 Presented by: Ms Johnson 02/11/2021 Unguided transmission media is data signals that flow through the air. They are not guided or bound to a channel. They are used mostly in instances where data needs to be transmitted over very long distances. Following Are unguided media used for data communication:  Infrared  Microwave  Satellite Presented by: Ms Johnson 02/11/2021 16 WIRELESS TRANSMISSION MEDIA Microwave: These have very sort wavelength, hence the word “micro”-wave. These powerful signals can be projected over long distances over a direct line of-sight path between any two points, such as antennae. Satellite: This is very similar to microwave transmission however instead of using two microwave dish antennae that are close to each other, it uses a satellite that is located in space.  Infrared: There are 2 main types of infrared communications used in schools are line of sight and scattered broadcast. Line of sight communication means that there must be unblocked direct line between the workstation and the transceiver. If a person walks within the line of sight while there is a transmission, the information world need o be sent again. This kin of obstruction can slow down the wireless networks. Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver. WIRELESS TRANSMISSION MEDIA 19 Presented by: Ms Johnson 02/11/2021  SWITCH, ROUTER OR MODEM These are all necessary in order to connect to the internet. The following are used to connect to the internet using a telephone line. Modem: this is provided by your internet service provider (ISP), who provides you with access to the internet. The purpose of the modem is to convert analogue and digital signals between landline and the internet. ISP’s providers in the Caribbean are Digicel and Flow. If you're using more than one computer with a modem, then you will need a router in addition to the modem. MODEM The word MODEM is an acronym for Modulator Demodulator. It is a device that is connected to a telephone line and a computer. The function of the modem is to convert the signals that comes to the telephone line in a digital format to analog format. The modem then converts that same signal back to digital form so that the computer can understand it. Telephone read only analog form and computers read only digital form. Presented by: Ms Johnson 02/11/2021 21  SWITCH, ROUTER OR MODEM ROUTER: This the “traffic cop” of a network. It directs data from the modem and sends it to the different devices that are connected to it. Devices such as computers, laptops, game consoles, digital televisions and mobile devices can be connected through cables directly to the router or wirelessly. The router typically assigns IP addresses to all the computers and devices. SWITCH: this simply expands the number of devices that can be connected to a router. Some routers, such as Netgear models, combine the three networking components – modem, router and switch- instead of having separate devices with cables joining them. Presented by: Ms Johnson 02/11/2021 23 NETWORK INTERFACE CARD / NETWORK ADAPTER A network interface card (NIC) or network adaptor is hardware that is usually already part of a computer or laptop. It provides the computer with a dedicated connection to a network. These are cards that can be used for wired or wireless connections to the network. Network interface card A network interface card (NIC) is a circuit board or card that is installed in a computer so that it can be connected to a network. NICs may be used for both wired and wireless connections. Presented by: Ms Johnson 02/11/2021 25 Network adapter This is a converter that adopts/extends a USB port in order for it to function like a NIC or a wireless NIC. A network adaptor is needed if the computing device does not have a built-in networking component. Presented by: Ms Johnson 02/11/2021 26 IMPORTANCE OF MOBILE COMMUNICATION TECHNOLOGIES Suitability of mobile networks to various applications (e.g.; education, commerce and journalism) Education: Online classes, Online resources, Emails, presentations, online classrooms, not limited to physical location. Commerce: Advertising of products, buying of products online, Journalism: online media sources, wider audiences, THE END