Global System for Mobile (GSM)/2G A selection of protocols that allow mobile phones to function (2G) No data General Packet Radio Service (GPRS)/2.5G 2.5G is 2G technology that allows the transfer of data. This includes two basic technologies. GPRS which is an adaption to basic GSM networks that allows data to be transferred 120Kbps to 384Kbps. EDGE (Enhanced Data rates for GSM Evolution or EGPRS)

WAP (not on the course)

Third Generation (3G) This is the third generation of technology and protocols that have been produced for mobile phones. Minimum speed of 200Kbits/s to 6Mbits/s Fourth Generation (4G) This is the latest generation of technology and protocols that allow for fast data speeds. It is due to be superseded by 5G. 5 to 50 Mbits/s

Why do they keep changing? People are demanding more from mobile phone connections. Faster internet More consumption of data More devices More density within towns and cities. In addition to that competition between companies and technology improves.

You will know SMS as a Text You will know SMS as a Text. It is the set of rules that allow two phones to send messages to each other. When it was fist launched it was seen as a gimmick and something that was unlikely to catch on. (1985) It did not hit the UK until 1992 on the vodaphone network You are limited to 160 characters. This can be “threaded” together to make longer messages. The SMS protocol have been updated several times as initially you could only send alpha numeric characters (not all characters for all languages). When an “emoji” is sent the sender and receiver will convert strings of text into icons… :>) :>( :>0 Or ?

Over-The-Air programming is a way of updating software on mobile devices (including TV’s) without requiring the device to be manually updated by the user. Updates are typically sent from a central location to all devices and the can update items like… + Firmware (the operating System) + Fix bugs + Add additional features + Update security Users can chose to refuse an update but many suppliers will make this difficult to do or can either roll out an update without confirming first with the user. Typically you will see OTA as an update to Android of iOS

Problems with OTA How is the data transferred and who pays for this? Could the update compromise the device? Who actually owns the device? If the device breaks during an update who is liable to fix it? If the user misses an update how does the device react they have not signal)

https://in-the-sky.org/satmap_worldmap.php https://www.n2yo.com/satellites/?c=20

Atomic clock An atomic clock is a clock that uses special electronics to keep exact time. Knowing the exact time is a major problem and is one that not many people often appreciate. All clocks will drift and lose time. In early days each town would have a town clock which was used by everyone. Once railways began the problem would be that each town would have different times. In 1930 it was proposed tat very sensitive electronics could be used to keep track of time exactly.

Fundamentals of GPS Developed by the American military as a way of keeping track of your location. At times of war the military turn off satellites over a set area so that GPS cannot be used. You must have line of site of 4 satellites in order to receive a signal. Each satellites will send s packet of data at set intervals. In the packet it will include…. + Location of the satellites + Time the packet was sent + Name of the satellites (+ Other data that is not relevant here)

Control segment Radar stations across the planet keep track of satellites and their locations. This is the same system that is used for tracking missiles.

Radio waves All electromagnetic radiation travels at the same speed which is about 3.0 * 108 meters per second We can tell how far away each satellite is based on how long this signal took to arrive.

Mobile broadband This is the brand name for products that provide an internet connection via a portable modem that uses standard mobile phone networks. Tethering This describes the process of attaching a mobile phone or device to a laptop of internet enabled device. Tethering can be completed via several methods… Using a wire or USB cable Bluetooth Portable WiFi