Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cell Phones and Computers Monica Leclerc Joseph Fasino Nicole Downs.

Similar presentations


Presentation on theme: "Cell Phones and Computers Monica Leclerc Joseph Fasino Nicole Downs."— Presentation transcript:

1 Cell Phones and Computers Monica Leclerc Joseph Fasino Nicole Downs

2 Cellular: A type of wireless communication that is most familiar to mobile phones users. It's called 'cellular' because the system uses many base stations to divide a service area into multiple 'cells'. Cellular calls are transferred from base station to base station as a user travels from cell to cell. (Bellis) History

3 The First Model First concept introduced in 1947 First concept introduced in 1947 Incorporated technology from car phones Incorporated technology from car phones Purely theoretical Purely theoretical No technology existed to support it No technology existed to support it

4 The FCC The Federal Communications Committee The Federal Communications Committee Queried by AT&T for allocation of radio frequencies Queried by AT&T for allocation of radio frequencies Supposed to motivate research Supposed to motivate research Suggested business profit capability Suggested business profit capability Granted limited amount Granted limited amount

5 The Problem The FCC was too wary of the new technology The FCC was too wary of the new technology Only allocated enough to sustain 23 conversations in one cell area Only allocated enough to sustain 23 conversations in one cell area Not suitable for large profit Not suitable for large profit Inhibited research and progress Inhibited research and progress

6 1968 FCC reconsiders FCC reconsiders if the technology to build a better mobile service works, we will increase the frequencies allocation, freeing the airwaves for more mobile phones. (Bellis) if the technology to build a better mobile service works, we will increase the frequencies allocation, freeing the airwaves for more mobile phones. (Bellis) AT&T and Bell Labs propose theories AT&T and Bell Labs propose theories Still no existing technology Still no existing technology

7 Dr. Martin Cooper Researcher for Motorola Researcher for Motorola Credited with inventing the first cellular phone Credited with inventing the first cellular phone 1973 made the first call to rival Joel Engel, Head Researcher from Bell Labs 1973 made the first call to rival Joel Engel, Head Researcher from Bell Labs Motorola first to use cell technology without the use of an automobile Motorola first to use cell technology without the use of an automobile

8 AT&T Follows Suit 1977 introduced their own patent 1977 introduced their own patent 1978 tested in Chicago with a trial of over 2, tested in Chicago with a trial of over 2,000

9 Technology of the cell phone

10 How it works They operate between cells and switch cells as a person moves around. They operate between cells and switch cells as a person moves around. When you make a call on your cell phone, it is wirelessly linked to the telephone network via these towers so your call can be connected. When you make a call on your cell phone, it is wirelessly linked to the telephone network via these towers so your call can be connected.

11 Towers Each tower, or base station, covers a roughly circular area called a cell Each tower, or base station, covers a roughly circular area called a cell This allows different base stations to use the same frequencies, or channels, for communication links as long as a sufficient distance separates them. This is known as frequency re-use, and allows thousands or even hundreds of thousands of mobile telephone users in a metropolitan area to share far fewer channels This allows different base stations to use the same frequencies, or channels, for communication links as long as a sufficient distance separates them. This is known as frequency re-use, and allows thousands or even hundreds of thousands of mobile telephone users in a metropolitan area to share far fewer channels

12 Making a call Transmits the number along with a request for service signal. Transmits the number along with a request for service signal. It then transmits this information on the strongest reverse control channel where the MTSO checks the information and assigns it to a voice channel. It then transmits this information on the strongest reverse control channel where the MTSO checks the information and assigns it to a voice channel. The cell site will then open a voice channel and transmit a SAT which is then locked onto the mobile and transmitted back to the cell site. The cell site will then open a voice channel and transmit a SAT which is then locked onto the mobile and transmitted back to the cell site. The info is then confirmed and sends a mobile message as either a busy signal or a ringback. The info is then confirmed and sends a mobile message as either a busy signal or a ringback.

13 3 generations of mobile technology: 1. Analog 2. Digital 3. Smart phones

14 The first generation of mobile technology is the analog cellular system The first generation of mobile technology is the analog cellular system Increase in the number of available channels Increase in the number of available channels The cell-phone carrier receives about 800 frequencies to use across a city. The cell-phone carrier receives about 800 frequencies to use across a city. The carrier chops up the city into cells, each cell is about 10 square miles and are on a giant hexagon grid. The carrier chops up the city into cells, each cell is about 10 square miles and are on a giant hexagon grid. Analog System

15 Cell Grid Each cell consists of a base tower through which signals are sent and received. Each cell consists of a base tower through which signals are sent and received. Each cell uses 1/7 of the available channels so its frequency is unique and the signals dont collide. Each cell uses 1/7 of the available channels so its frequency is unique and the signals dont collide.

16 2G Digital Transmission Increase in the number of available channels within a given bandwidth. Increase in the number of available channels within a given bandwidth. It compresses your voice into binary information which allows 3-10 digital phones to occupy the space of one single analog call. It compresses your voice into binary information which allows 3-10 digital phones to occupy the space of one single analog call. Frequency shift keying sends data back and forth over AMPS using 2 alternate frequencies,1s and 0s, alternating rapidly between the two to send digital information between the cell tower and the phone. Frequency shift keying sends data back and forth over AMPS using 2 alternate frequencies,1s and 0s, alternating rapidly between the two to send digital information between the cell tower and the phone. They have a lot of processing power. They have a lot of processing power.

17 Sharing technologies 2G & 3G Frequency division multiple access (FDMA) Frequency division multiple access (FDMA) –Puts each call on a separate frequency. Time division multiple access (TDMA) Time division multiple access (TDMA) –Assigns each call a certain amount of time on its designated frequency. Code division multiple access (CDMA) Code division multiple access (CDMA) –Gives each call its own unique code and spreads it over the available frequencies

18 FDMA TDMA CDMA

19 3G Smart phones Intended for true multimedia use- referred to as smart phones Intended for true multimedia use- referred to as smart phones Smart phones are intended to allow you to use other programs on the phone that you couldnt use with a standard phone. Smart phones are intended to allow you to use other programs on the phone that you couldnt use with a standard phone. Increased bandwidth and has transfer rates to accommodate the internet. Increased bandwidth and has transfer rates to accommodate the internet. It contains many cellular technologies but the 3 most common are: Code Division Multiple Access, Wideband Code Division Multiple Access, and Time-division Synchronous Code-division Multiple Access. It contains many cellular technologies but the 3 most common are: Code Division Multiple Access, Wideband Code Division Multiple Access, and Time-division Synchronous Code-division Multiple Access.

20 Analog DigitalSmart phone

21 Taking it apart Circuit board – brains of the phone Circuit board – brains of the phone Antenna Antenna Liquid Crystal Display (LCD) Liquid Crystal Display (LCD) Keyboard Keyboard Microphone Microphone Speaker Speaker Battery Battery

22 FrontBack Circuit board Contains an analog-to- digital and digital-to- analog conversion chip which translates the outgoing audio signal from analog to digital and the incoming signal from digital back to analog. Contains an analog-to- digital and digital-to- analog conversion chip which translates the outgoing audio signal from analog to digital and the incoming signal from digital back to analog.

23 LCD, keypad, and other parts Thinner, lighter, use less battery power than other displays Thinner, lighter, use less battery power than other displays Speaker, microphone and battery backups Speaker, microphone and battery backups

24 Microprocessor & Flash memory The microprocessor deals with command and control signaling with the base station. It also coordinates the functions of the keyboard and display. The microprocessor deals with command and control signaling with the base station. It also coordinates the functions of the keyboard and display. The flash memory and ROM chips provide storage for the operating system and customizable phone features. The flash memory and ROM chips provide storage for the operating system and customizable phone features. Some phones use internal memory to store info while others use the external memory card. Some phones use internal memory to store info while others use the external memory card.

25 Four Main Carriers Verizon Wireless Verizon Wireless T-Mobile T-Mobile Cingular Cingular Sprint/Nextel Sprint/Nextel

26 Comparing Plans PlanCostMinutes Overage Cost Nights & Weekends Extra Verizon Basic $ $0.45/ Per Min Free 9pm Nights & Weekends Mobile to Mobile T-Mobile Basic $ $0.40/ Per Min Free Weekends None T-Mobile MyFave $ $0.40/ Per Min Free Weekends Free to 5 numbers Basic Cingular $ $0.45/ Per Min Rollover Mobile to Mobile Basic Sprint $ $5 for 30 Min plus $0.20 after 500 min Free 7pm Nights & Weekends None Basic Nextel $ N/A Free 9pm Nights & Weekends Free Nextel Walkie- Talkie

27 Add-ons for Phones Text Messaging Text Messaging Multimedia Messaging Multimedia Messaging Internet Internet Instant Messaging Instant Messaging MP3 Player MP3 Player Maps Maps News & Weather News & Weather Custom Ring Tones Custom Ring Tones Ring Back Tones Ring Back Tones Video Player Video Player


Download ppt "Cell Phones and Computers Monica Leclerc Joseph Fasino Nicole Downs."

Similar presentations


Ads by Google