21 st november 2014 Iphone texting-internet-apps- when texting it sends wirelessly to the reciver Laptop-downloading-internet- it travels using cables to download from the internet to the computer House phone- calling- it travels wirelessly to another phone buts connected to cables Texts to talk to people- Messages are delived wirelessly Snapchat to snap people- Messages are delived wirelessly Facebook to message -Messages are delived wirelessly Data exchange is all methods of passing data between devices components and users over a network. Data is anything you can send eg: pictures, texts, videos, audio. Devices are phones, tablets, printers. Voice over internet protocol Voice and video over the internet You need webcam, speakers, microphone. Voice is encoded then decoded on the other computer called codec. The program digitalises your voice signal and turns in into internet packets and reverts it at the other end. Wireless communications use radio waves or infrared. your device needs a wireless interface card to have wireless connection. The card is used to transmit data to and from the network. Unshielded twisted pair cables are basic pairs or cables twisted together Shielded twisted pair cables are the same but with a foil shield Max data 250Mbps Max range 100m Benefits twisting cancels out some interference and low cost Limitations, slower, less capacity than others and can only be used for short distances E.G. analogue telephone network Solid wire separated from a copper outer by a plastic insulated sheet The inner cable transmits data and the outer connects to the earth Max data 1000mbps Max range 100m Fast&reliable Cost more than utp/stp Eg. Connection to tv network Glass or plastic cables which uses internal reflection of lite to transmit data. Normally uses led or laser visible light Max data 2.4gbs Max range 50km Fast, long distances Complex connections and equipment needed Eg. Fiber optic broadband, connects to bt panels in the street then uses coaxial cables to the house. Short range data transmition that uses infared light Max data 4mbps Max range 100m Short range, must be in line of sight Reliable Tv controls and some phones Short wave length radio transition and a very high frequency Max data 300gbps Max range 100m Signal dose not degrade over long distances Divice must be in line of sight, is affected by weather Bluetooth satellite Satellite is used for TV transitions, connects to tv channels via The satellite. Data is transmitted from earth to a satellite which relayed it back to another station on earth Max data huge Max range 500km/36,000km Expensive Global communication Distance and speed Sends data in only 1 direction Radio broadcasting Sends data in both directions But only one at a time Maximise band with Sends data in both directs at the same time telephone Data is transmitted simultaneously Over an equal number of wires and cables. Allows the data to be transmitted together so you dont have to wait because its sent at the same time Max of 5 meters because it has a short range Used to be used to connect printers to your computer but now its only used for a small number of things because its to costly and the range is only 5 meters Transmitting in both directions Fiber optic used this technology at the same time using 2 cables not 1 Bits are transmitted one at a time over a single channel This reduces the cost of the cable but gives a slower rate of transfer They have to be disassembled into individual bits for transmition then reassembled at the other end. Can be used over large distances. Universal sereal bus Sends data one bit at a time Introduced to make it easy to import to several devices All devices that use usb Xbox Charger Memory stick Satnav Computers Tvs Typically, a client is a computer application, such as a web browser, that runs on a user's local computer or workstation and connects to a server as necessary. Could result in viruses Typically, a server is a computer program, such as a web server, that runs on a remote server, reachable from a user's local computer or workstation. If you have no computer how are you going to charge it up? You need to have good connection Client side processing: This is Taking place on the computer. Interactive features on a webpage are downloaded on to the computer and then processed away from the web server The website code (web script) is interpreted by the web browser different browsers may translate the code differently Game is downloaded on webpage, you do not sent to or from server it all happens just on the webpage and YOUR computer and no were else. Advantages; Quicker because it hasnt got to go to and from the server. Speed, fast to connect and download quickly Security, not comment to hacks or bugs. Disadvantages; Browser specific, can only show up the way you want it on certain browsers Computer speed, the computer may not be fast even though your software is faster. Server side: Data is sent back and forth from server and computer Because the processing is done on the web server it dont matter about which browser you use. An example of this would be completing an online form as the results are processed and stored on the server. Advantage: Doesn't matter about web browser, browser independent. Speed does not matter. Disadvantage; Relies on the server, the server can over load if to many people are using it Security, can be intercepted much easier bc its not staying on your computer