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Cell Phones


This is an example of cell phones. This document is useful for studying cell phones.

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									          Devin Cifers, Drew Tingen, Steven Walters
                               Cell Phones, the End of the Beginning

Cell phones are all around us. They are based on the two-way radio. Being extremely limited on

available frequencies, companies implemented the cell, thus providing the name. Cell phones

are not perfect devices, so accordingly cell phones continue to acquire more and more

capabilities and advancements. Most of these improvements are not even thought of at the

present moment, while some improvements are being developed to make cell phones have every

electronic capability. Cell phones can now repel mosquitoes, send text messages, capture

images, and even perform simple calculations. This is the end of the beginning of cell phones

and their usage and development.

          Cell phones are a miracle of modern technology to many. People around the globe use

cellular phones to call others around the world. We have all seen cell phones and many of us use

them daily, but why are they so useful and most importantly how do they work. These are the

questions that many people leave unasked and unanswered even though they are why we have

such great conveniences as the cell phone and other recent innovations. The concept for cellular

communication is not a difficult one to understand, just extremely complex on the large scale,

which the world uses today. Cell phone technology is rapidly advancing as new features, such as

gaming, web browsing, and text messaging are added to each new phone. There are

improvements and extras to cell phones still in development that will make them even more


          Well, what is a cell phone exactly and why are they so popular? These questions are

much more common than you might think. Many people believe that a technology that is as

widely used as the cell phone must be extremely complex and incredibly hard to decipher.

Actually the concept behind cell phones is really quite simple. Have you ever used a two way
       Devin Cifers, Drew Tingen, Steven Walters
radio? That is exactly what a cell phone is, an enhanced two way radio. Cities, states, and

countries are divided into hexagonal cells, and each cell has its own tower. The cell phone,

which has a low power radio transmitter, only communicates with the nearest tower, the one in

its current cell (Brain). The tower then communicates with a central office for the telephone

company. The company then finds the other phone and connects you to them, whether it is

another cell phone or a regular house phone. So it’s just like talking over a two way radio with

someone a few hundred yards away, only cell phones can talk hundreds of miles away.

Similarly, to talk internationally or overseas the cell phone communicates with the tower witch

communicates with the base station of the telephone company, then the company sends the

signal via satellite overseas to the other telephone companies and their respective cell towers.

       It can’t be that easy, many would say. The concept is simple, but the actual workings of

a call are much more complex. Cell phones can’t just talk to any tower anywhere at any time

and expect to be able to receive calls. Each cell phone, when turned on, looks for identification

number from the towers called the System Identification Code or SID. The SID is a unique five

digit code given to each carrier by the FCC (Brain). If the cell phone is unable to find its carriers

SID then it is out of range of any active tower for that carrier and shows some type of no service
       Devin Cifers, Drew Tingen, Steven Walters
or no signal message (Brain). Once the phone identifies its carriers SID it can communicate with

the carrier and make and receive calls. Of course the tower must also be able to identify the cell

phone who it is talking to at that time. In order to do this there are several forms of identification

which a cell phone possesses, one of which is the number of the phone. Actually, the carrier

does not identify the cell by its number, but by its MIN, or Mobile Identification Number, which

is a 10-digit number derived from the cell phone call number (Brain). Using this number the

base station can identify the cell phone on the network and find the cell phone it is attempting to

call and connect them. As long as the cell tower can talk to and identify the cell phone, it is able

to make calls and receive calls, but what happens as you are driving and leave the area of your

current tower? As the cell phone moves further away from the tower in its current cell the signal

begins to dissipate because it only has a low level transmitter, using signal strengths of either .6

watts or 3 watts (Brain). The base station for that cell notes that your signal is decreasing and

switches you over to the next cell when your signal reaches a certain level. From that point you

are communicating with that tower in the next cell until you reach the edge of that cell. Each cell

is approximately 26 square kilometers in area (Brain). If you run out of every cell in a carriers

system in that area then the cell phone loses its entire signal and cannot receive or make calls, all

calls are diverted to a possible messaging service.

       Cell phones only have low level transmitters; some would ask why companies don’t just

equip their phones with high level transmitters so they would need as many cells. There is a good

reason for that. The FCC assigns cell companies certain frequencies in which their phones can

operate; they must operate within the range which they are assigned. However, no two phones

can use the same frequencies in the same cell simultaneously for two different calls. Normally a

carrier is given only 823 frequencies per city. Each cell phone uses two different frequencies per
       Devin Cifers, Drew Tingen, Steven Walters
call so there are only about 400 voice channels per cell per carrier (Brain). If the company

breaks down the cells into smaller cells and use low power transmitters they can reuse the

different frequencies for more phones in every other cell. Doing this, the carrier can

accommodate more people over a much wider area at the same time; it’s better for business and

it makes more people have the ability to use cell phones.

       Cell phones of today can do so much more than just let people talk to one another. Now

they are becoming ways for people to pass the time and communicate in other ways than vocal

signals. You can browse the internet and send email, text message other cell phones and even

calculate tip for a dinner out you just had with that special someone. It’s amazing the things that

cell phones can do now, but this is only the beginning of the development of the cell phone. One

recent development in cell phone technology even allows you to download a piece of software

that transmits a frequency which repels mosquitoes up to a meter away, which doesn’t seem like

much, but it keeps them from biting (Deok-hyun). There are many things cell phones could

possibly be used for that are still to be developed, some things haven’t even been thought of yet.

For example, one new innovation that could be developed for the cell phone could be a special

phone made for disabled people. The phone could be connected to their entire house and be used

as a remote control to open cabinets, cook dinner, and answer the door. This phone would be a

great convenience and would help decrease the amount of human attention or nursing a person

might need after having surgery. Another tool which cell phones might be able to use would be

a tracking device. If each person in a household had a cell phone that could emit a certain signal

that the other phones could recognize people would be able to find their family members if they

were within range. This would be useful in places like the mall; if someone was separated from

a group the group could track them down just by turning on a cell phone. Cell phones have been
       Devin Cifers, Drew Tingen, Steven Walters
tested and it has been proven that cell phones emit low level electromagnetic radiation which

over a period of time could cause cancer. Because of this fact the FDA has begun to regulate cell

phones and the amount of radiation which cell phones can emit (“Cell Phone Facts: Consumer

Information of Wireless Phones”). What if someone could develop an electromagnetic shield

that would cancel the radiation generated by the cell phone which in turn reduces the health risk?

Wouldn’t that be useful?

       Cell phones are really amazing tools. They have brought telecommunication to an

entirely new level which people would never have dreamed of 10 or 15 year ago. Now instead

of just talking to one another from hundreds to thousands of miles away people can send text

messages, check email, play games, and even repel bugs with software. This is only the end of

the beginning in a sense. Cell phones have only truly become popular in the past couple of years

and most people still don’t have one of their own, but with technology rapidly developing cell

phones are sure to become even more popular than they are now. And with the popularity rising,

the demand for even more new features will certainly appear. Cell phones are a tool that will

change the way we live, without question.

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