Cell Phones and Cell Phones and ComputersComputersMonica LeclercMonica LeclercJoseph FasinoJoseph FasinoNicole DownsNicole Downs

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

The First ModelThe First Model• First concept introduced in 1947First concept introduced in 1947• Incorporated technology from car phonesIncorporated technology from car phones• Purely theoreticalPurely theoretical• No technology existed to support it No technology existed to support it

The FCCThe FCC• The Federal Communications The Federal Communications

CommitteeCommittee• Queried by AT&T for allocation of Queried by AT&T for allocation of

radio frequenciesradio frequencies• Supposed to motivate researchSupposed to motivate research• Suggested business profit capabilitySuggested business profit capability• Granted limited amountGranted limited amount

The ProblemThe Problem• The FCC was too wary of the new The FCC was too wary of the new

technologytechnology• Only allocated enough to sustain 23 Only allocated enough to sustain 23

conversations in one cell areaconversations in one cell area• Not suitable for large profitNot suitable for large profit• Inhibited research and progressInhibited research and progress

19681968• FCC reconsidersFCC reconsiders• ““if the technology to build a better if the technology to build a better

mobile service works, we will increase mobile service works, we will increase the frequencies allocation, freeing the the frequencies allocation, freeing the airwaves for more mobile phones”. airwaves for more mobile phones”. (Bellis) (Bellis)

• AT&T and Bell Labs propose theoriesAT&T and Bell Labs propose theories• Still no existing technologyStill no existing technology

Dr. Martin CooperDr. Martin Cooper• Researcher for MotorolaResearcher for Motorola• Credited with inventing the first Credited with inventing the first

cellular phonecellular phone• 1973 made the first call to rival Joel 1973 made the first call to rival Joel

Engel, Head Researcher from Bell LabsEngel, Head Researcher from Bell Labs• Motorola first to use cell technology Motorola first to use cell technology

without the use of an automobilewithout the use of an automobile

AT&T Follows SuitAT&T Follows Suit• 1977 introduced their own patent1977 introduced their own patent• 1978 tested in Chicago with a trial of 1978 tested in Chicago with a trial of

over 2,000over 2,000

Technology of the cell Technology of the cell phonephone

How it worksHow it works• They operate between cells and They operate between cells and

switch cells as a person moves switch cells as a person moves around.around.

• When you make a call on your cell When you make a call on your cell phone, it is wirelessly linked to the phone, it is wirelessly linked to the telephone network via these towers telephone network via these towers so your call can be connected. so your call can be connected.

TowersTowers• Each tower, or base station, Each tower, or base station,

covers a roughly circular covers a roughly circular area called a cellarea called a cell

• This allows different base This allows different base stations to use the same stations to use the same frequencies, or channels, for frequencies, or channels, for communication links as long communication links as long as a sufficient distance as a sufficient distance separates them. This is separates them. This is known as frequency re-use, known as frequency re-use, and allows thousands or and allows thousands or even hundreds of thousands even hundreds of thousands of mobile telephone users in of mobile telephone users in a metropolitan area to share a metropolitan area to share far fewer channels far fewer channels

Making a callMaking a call• Transmits the number along with a request for Transmits the number along with a request for

service signal.service signal.• It then transmits this information on the It then transmits this information on the

strongest reverse control channel where the strongest reverse control channel where the MTSO checks the information and assigns it to MTSO checks the information and assigns it to a voice channel.a voice channel.

• The cell site will then open a voice channel The cell site will then open a voice channel and transmit a SAT which is then locked onto and transmit a SAT which is then locked onto the mobile and transmitted back to the cell the mobile and transmitted back to the cell site.site.

• The info is then confirmed and sends a mobile The info is then confirmed and sends a mobile message as either a busy signal or a ringback.message as either a busy signal or a ringback.

3 generations of mobile 3 generations of mobile technology:technology:

1.1. AnalogAnalog2.2. DigitalDigital3.3. Smart phonesSmart phones

• The first generation of mobile The first generation of mobile technology is the analog cellular systemtechnology is the analog cellular system

• Increase in the number of available Increase in the number of available channelschannels

• The cell-phone carrier receives about The cell-phone carrier receives about 800800 frequencies to use across a city.frequencies to use across a city.

• The carrier chops up the city into cells, The carrier chops up the city into cells, each cell is about 10 square miles and each cell is about 10 square miles and are on a giant hexagon grid. are on a giant hexagon grid.

Analog System

Cell GridCell Grid• Each cell consists of Each cell consists of

a base tower through a base tower through which signals are which signals are sent and received.sent and received.

• Each cell uses 1/7 of Each cell uses 1/7 of the available the available channels so its channels so its frequency is unique frequency is unique and the signals don’t and the signals don’t collide.collide.

2G Digital Transmission2G Digital Transmission• Increase in the number of available channels Increase in the number of available channels

within a given bandwidth.within a given bandwidth.• It compresses your voice into binary It compresses your voice into binary

information which allows 3-10 digital phones information which allows 3-10 digital phones to occupy the space of one single analog call.to occupy the space of one single analog call.

• Frequency shift keying sends data back and Frequency shift keying sends data back and forth over AMPS using 2 alternate forth over AMPS using 2 alternate frequencies,1s and 0s, alternating rapidly frequencies,1s and 0s, alternating rapidly between the two to send digital information between the two to send digital information between the cell tower and the phone. between the cell tower and the phone.

• They have a lot of processing power.They have a lot of processing power.

Sharing technologies 2G & Sharing technologies 2G & 3G3G• Frequency division multiple access (FDMA)Frequency division multiple access (FDMA)

– Puts each call on a separate frequency. 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 Assigns each call a certain amount of time on its designated frequency. its designated frequency.

• Code division multiple access (CDMA) Code division multiple access (CDMA) – Gives each call it’s own unique code and Gives each call it’s own unique code and

spreads it over the available frequenciesspreads it over the available frequencies

FDMATDMA

CDMA

3G Smart phones3G Smart phones• Intended for true multimedia use- referred to Intended for true multimedia use- referred to

as smart phonesas smart phones• Smart phonesSmart phones are intended to allow you to use are intended to allow you to use

other programs on the phone that you couldn’t other programs on the phone that you couldn’t use with a standard phone.use with a standard phone.

• Increased bandwidth and has transfer rates to Increased bandwidth and has transfer rates to accommodate the internet.accommodate the internet.

• It contains many cellular technologies but the It contains many cellular technologies but the 3 most common are: Code Division Multiple 3 most common are: Code Division Multiple Access, Wideband Code Division Multiple Access, Wideband Code Division Multiple Access, and Time-division Synchronous Code-Access, and Time-division Synchronous Code-division Multiple Access. division Multiple Access.

Analog Digital Smart phone

Taking it apartTaking it apart• Circuit board – brains Circuit board – brains

of the phoneof the phone• AntennaAntenna• Liquid Crystal Display Liquid Crystal Display

(LCD)(LCD)• KeyboardKeyboard• Microphone Microphone • SpeakerSpeaker• BatteryBattery

Front

Back

Circuit boardCircuit board• Contains an analog-to-Contains an analog-to-

digital and digital-to-digital and digital-to-analog conversion chip analog conversion chip which translates the which translates the outgoing audio signal outgoing audio signal from analog to digital from analog to digital and the incoming signal and the incoming signal from digital back to from digital back to analog. analog.

LCD, keypad, and other LCD, keypad, and other partsparts• Thinner, lighter, Thinner, lighter,

use less battery use less battery power than other power than other displaysdisplays

Speaker, Speaker, microphone and microphone and battery backupsbattery backups

Microprocessor & Flash Microprocessor & Flash memorymemory• The microprocessor deals with The microprocessor deals with

command and control signaling command and control signaling with the base station. It also with the base station. It also coordinates the functions of the coordinates the functions of the keyboard and display.keyboard and display.

• The flash memory and ROM chips The flash memory and ROM chips provide storage for the operating provide storage for the operating system and customizable phone system and customizable phone features.features.

• Some phones use internal Some phones use internal memory to store info while others memory to store info while others use the external memory card.use the external memory card.

Four Main CarriersFour Main Carriers•Verizon WirelessVerizon Wireless•T-MobileT-Mobile•CingularCingular•Sprint/NextelSprint/Nextel

Comparing PlansComparing PlansPlanPlan CostCost MinutesMinutes Overage Overage

CostCostNights & Nights & WeekendWeekendss

ExtraExtra

Verizon Verizon BasicBasic

$39.99$39.99 450450 $0.45/$0.45/Per MinPer Min

Free 9pm Free 9pm Nights & Nights & WeekendsWeekends

Mobile to Mobile to MobileMobile

T-Mobile T-Mobile BasicBasic

$29.99$29.99 300300 $0.40/ Per $0.40/ Per MinMin

Free Free WeekendsWeekends

NoneNone

T-Mobile T-Mobile “MyFave”“MyFave”

$39.99$39.99 300300 $0.40/ Per $0.40/ Per MinMin

Free Free WeekendsWeekends

Free to 5 Free to 5 numbersnumbers

Basic Basic CingularCingular

$39.99$39.99 450450 $0.45/ Per $0.45/ Per MinMin

RolloverRolloverMobile to Mobile to MobileMobile

Basic Basic SprintSprint

$29.99$29.99 200200 $5 for 30 $5 for 30 Min plus Min plus $0.20 after $0.20 after 500 min500 min

Free 7pm Free 7pm Nights & Nights & WeekendsWeekends

NoneNone

Basic Basic NextelNextel

$49.99$49.99 400400 N/AN/A Free 9pm Free 9pm Nights & Nights & WeekendsWeekends

Free Free Nextel Nextel Walkie-Walkie-TalkieTalkie

Add-ons for PhonesAdd-ons for Phones• Text MessagingText Messaging• Multimedia Multimedia

MessagingMessaging• E-mailE-mail• InternetInternet• Instant MessagingInstant Messaging• MP3 PlayerMP3 Player

• MapsMaps• News & WeatherNews & Weather• Custom Ring Custom Ring

TonesTones• Ring Back TonesRing Back Tones• Video PlayerVideo Player