The Evolution of the Cell The Evolution of the Cell Phone…Phone…

……and a little bit about Bluetooth and a little bit about Bluetooth

Some facts to think about…Some facts to think about… A mobile phone is designed to operate at a maximum power level of A mobile phone is designed to operate at a maximum power level of

0.6 watts. A household microwave oven uses between 600 and 0.6 watts. A household microwave oven uses between 600 and 1,100 watts.1,100 watts.

In 1994, 16 million Americans subscribed to cellular phone services. In 1994, 16 million Americans subscribed to cellular phone services. Today, more than 110 million Americans are subscribers. Some Today, more than 110 million Americans are subscribers. Some experts predict that worldwide subscribership will reach 1.2 billion experts predict that worldwide subscribership will reach 1.2 billion people by 2005.people by 2005.

In a 2005 University of Michigan study, 83 percent said In a 2005 University of Michigan study, 83 percent said cellcell phones phones have made life easier, choosing it over the Internet (76 percent). But have made life easier, choosing it over the Internet (76 percent). But an additional 60 percent said they find an additional 60 percent said they find cellcell phones somewhat phones somewhat irritating when used in public.irritating when used in public.

The BBDO survey found that 75 percent of The BBDO survey found that 75 percent of cellcell phonephone owners had owners had it turned on and within reach during their waking hours, 59 percent it turned on and within reach during their waking hours, 59 percent wouldn't think of lending their wouldn't think of lending their cellcell phonephone to a friend for a day, 26 to a friend for a day, 26 percent said it was more important to go home to retrieve a percent said it was more important to go home to retrieve a cellcell phone phone than a wallet.than a wallet.

History of the Cellular PhoneHistory of the Cellular Phone

In 1843 a man by the name of Michael Faraday In 1843 a man by the name of Michael Faraday studied to see if space could conduct electricity. studied to see if space could conduct electricity.

In the year of 1865, Doctor Mahlon Loomis was In the year of 1865, Doctor Mahlon Loomis was the first person to communicate through wireless the first person to communicate through wireless atmosphere. atmosphere. He came up with the idea of transmitting and He came up with the idea of transmitting and

receiving messages through atmosphere as a receiving messages through atmosphere as a conductor. conductor.

In 1973 martin copper came up with Motorola. In 1973 martin copper came up with Motorola. In 1977 the first cell phone was made in In 1977 the first cell phone was made in

Chicago. Chicago. When it first came out 2000 people was given a free When it first came out 2000 people was given a free

trial. trial.

What exactly is a cell phone?What exactly is a cell phone?

One of the most interesting things One of the most interesting things about a cell phone is that it is about a cell phone is that it is actually a radio -- an extremely actually a radio -- an extremely sophisticated radio, but a radio sophisticated radio, but a radio nonetheless.nonetheless.

The genius of the cellular system is The genius of the cellular system is the division of a city into small cells. the division of a city into small cells. This allows extensive frequency This allows extensive frequency reuse across a city, so that millions reuse across a city, so that millions of people can use cell phones of people can use cell phones simultaneously. simultaneously.

In a typical analog cell-phone system In a typical analog cell-phone system in the United States, the cell-phone in the United States, the cell-phone carrier receives about carrier receives about 800 800 frequencies to use across the city. frequencies to use across the city.

Are you in my network? Are you in my network?

So why are they called “cellular” So why are they called “cellular” phones?phones?

A single cell in an analog system uses one-seventh of A single cell in an analog system uses one-seventh of the available duplex voice channels. That is, each cell (of the available duplex voice channels. That is, each cell (of the seven on a hexagonal grid) is using one-seventh of the seven on a hexagonal grid) is using one-seventh of the available channels so it has a unique set of the available channels so it has a unique set of frequencies and there are no collisions: frequencies and there are no collisions: A cell-phone carrier typically gets 832 radio frequencies to use in A cell-phone carrier typically gets 832 radio frequencies to use in

a city. a city. Each cell phone uses two frequencies per call -- a duplex Each cell phone uses two frequencies per call -- a duplex

channel -- so there are typically 395 voice channels per carrier. channel -- so there are typically 395 voice channels per carrier. (The other 42 frequencies are used for control channels -- more (The other 42 frequencies are used for control channels -- more on this later.) on this later.)

Therefore, each cell has about 56 voice channels available. Therefore, each cell has about 56 voice channels available. In other words, in any cell, 56 people can be talking on their In other words, in any cell, 56 people can be talking on their

cell phone at one time. cell phone at one time.

Analog vs. DigitalAnalog vs. Digital Analog cellular Analog cellular

systems are systems are considered first-considered first-generation mobile generation mobile technology, or 1G.technology, or 1G.

Digital transmission Digital transmission methods (2G), the methods (2G), the number of available number of available channels increases. channels increases. For example, a TDMA-For example, a TDMA-

based digital system based digital system can carry three times can carry three times as many calls as an as many calls as an analog system, so each analog system, so each cell has about 168 cell has about 168 channels available. channels available.

The major components…The major components…

Cell phones have low-Cell phones have low-power transmitters in power transmitters in them. them.

Many cell phones Many cell phones have two signal have two signal strengths: 0.6 watts strengths: 0.6 watts and 3 watts and 3 watts

For comparison, most For comparison, most CB radios transmit at CB radios transmit at 4 watts. 4 watts.

So how does it all work?So how does it all work?

When you first power up the When you first power up the phone, it listens for an phone, it listens for an SID SID (system identification #)(system identification #). . The control channel is a The control channel is a

special frequency that the special frequency that the phone and base station use phone and base station use to talk to one another about to talk to one another about things like call set-up and things like call set-up and channel changing. channel changing.

If the phone cannot find any If the phone cannot find any control channels to listen to, it control channels to listen to, it knows it is knows it is out of rangeout of range and and displays a "no service" displays a "no service" message. message.

So how does it all work?So how does it all work?

When it receives the SID, the phone compares it to the When it receives the SID, the phone compares it to the SID programmed into the phone. SID programmed into the phone. The phone knows that the cell it is communicating with is part of The phone knows that the cell it is communicating with is part of

its home system. its home system.

Along with the SID, the phone also transmits a Along with the SID, the phone also transmits a registration request, and the MTSO (registration request, and the MTSO (Mobile Telephone Mobile Telephone Switching OfficeSwitching Office) keeps track of your phone's location ) keeps track of your phone's location in a database -- this way, the MTSO knows which cell in a database -- this way, the MTSO knows which cell you are in when it wants to ring your phone. you are in when it wants to ring your phone.

The MTSO gets the call, and it tries to find you. It looks The MTSO gets the call, and it tries to find you. It looks in its database to see which cell you are in. in its database to see which cell you are in.

The MTSO picks a frequency pair that your phone will The MTSO picks a frequency pair that your phone will use in that cell to take the call. use in that cell to take the call.

Your cellular network…Your cellular network…

So what exactly is Bluetooth?So what exactly is Bluetooth?

There are lots of different ways that electronic There are lots of different ways that electronic devices can connect to one another: devices can connect to one another: Component cables Component cables Electrical wires Electrical wires Ethernet cables Ethernet cables WiFi WiFi Infrared signals Infrared signals

A Bluetooth connection is wireless and A Bluetooth connection is wireless and automatic, and it has a number of interesting automatic, and it has a number of interesting features that can simplify our daily lives. features that can simplify our daily lives.

Benefits of Bluetooth…Benefits of Bluetooth…

Bluetooth takes small-area networking to the Bluetooth takes small-area networking to the next level by removing the need for user next level by removing the need for user intervention and keeping transmission power intervention and keeping transmission power extremely low to save battery power. extremely low to save battery power.

Bluetooth is essentially a networking standard Bluetooth is essentially a networking standard that works at two levels: that works at two levels: Provides agreement at the physical level -- Bluetooth Provides agreement at the physical level -- Bluetooth

is a radio frequency standard. is a radio frequency standard. Provides agreement at the protocol levelProvides agreement at the protocol level

Think about this…Think about this… You're on your Bluetooth-enabled cell phone, standing outside the You're on your Bluetooth-enabled cell phone, standing outside the

door to your house. You tell the person on the other end of the line door to your house. You tell the person on the other end of the line to call you back in five minutes so you can get in the house and put to call you back in five minutes so you can get in the house and put your stuff away. As soon as you walk in the house, the map you your stuff away. As soon as you walk in the house, the map you received on your cell phone from your car's Bluetooth-enabled GPS received on your cell phone from your car's Bluetooth-enabled GPS system is automatically sent to your Bluetooth-enabled computer, system is automatically sent to your Bluetooth-enabled computer, because your cell phone picked up a Bluetooth signal from your PC because your cell phone picked up a Bluetooth signal from your PC and automatically sent the data you designated for transfer. .and automatically sent the data you designated for transfer. .

Can you hear me now?Can you hear me now?

So lets review:So lets review: Cell phones technology was actually invented in Cell phones technology was actually invented in

1843.1843. Cell phones are used by 110 million people in the US Cell phones are used by 110 million people in the US

today.today. The term “cellular” came from the type of radio The term “cellular” came from the type of radio

network which is used for cell phones to network which is used for cell phones to communicate.communicate.

Older cell phones used analog signals, while today’s Older cell phones used analog signals, while today’s cell phones use digital signals.cell phones use digital signals.

Bluetooth technology helps to integrate all forms of Bluetooth technology helps to integrate all forms of communication technology from your cell phone to communication technology from your cell phone to your television.your television.