How Do Cell Phones Work?
Nelson Oduro
SUNY Oswego
Information Science 110, Section 800
Professor Elaine Wenderholm
December 05, 2013
Nowadays, cell phones are everywhere. Cell phones are being carried by almost everyone
around the world including children, teenagers, adults, as well as grandparents. There is nothing
really nice about spotting someone on your way outside on his or her cell phone. As being
notified, phone companies are one of the fastest growing businesses on the market. This is
because technology is blooming. Every now and then, there are new phones that are released in
the market. Marketing strategies like new features are being used to update phones to make the
phone looks different. Phones nowadays can perform many tasks such as web browsing, making
phone, checking email, GPS locations, and more.
There were about 87% adults own cell phones in 2012 excluding teenagers. Statistics also
predicted that in 2013, the population of those who use phones would increase. Also according to
Mr. Wang, there were about seven billion people that were using cellphones worldwide. Since
there are so many cellphones users around the world we ask the question, how cellphone works.
What is a cellphone?
According to the article “how a cell phone works”, a cell phone is mainly a two way
radio, which consists of a radio transmitter and a radio receiver. As we talk to someone on a cell
phone, the phone converts the voice into an electrical signal, which is then transmitted through
radio waves to the nearest cell tower. The network of cell towers then communicates the radio
wave to the person’s cell phone, which transforms it to an electrical signal and then back to
sound again. Cell phones use radio waves to communicate. Radio waves transport digitized voice
or data in the form of wavering electric and magnetic fields, called the electromagnetic field
(EMF). The rate of alternation is called frequency.
Based on the article “how do cell phones work” Radio waves transport the information
and travel in air at the speed of light. There are several directions which cell phone radio waves
are transmitted. All waves are absorbed and reflected through surrounding objects before the
waves reach the nearest cell tower. Also most cell phones have at least one built in radio antenna
in order to transmit or receive radio signals. An antenna transforms an electric signal to the radio
wave (transmitter) and vice versa (receiver). Some cell phones use more than one transmitter and
receiver antenna, while in some cell phones only has one transmitter and receiver antenna. For
example, the iPhone has more than one transmitter and receiver antenna. An antenna helps us to
transmit and receive frequencies of radio waves, but in some older generation phones, some
antennas were external or extractable. Due to the blooming of technology, modern phones have
compactable antennas inside them. All metal components in the device like the circuit board
metal frame in the iPhone can cooperate with the spread antennas and also contribute to the
outline transmitted signal. (How do cell phones work, 2004)
According to “The Physics of Cell Phones”, in every two to three miles, there is a phone
tower that helps the phone to communicate with others to get service. Cell phones transmit to
towers, which then connects you to the normal land based telephone system to route a phone call.
A large city has hundreds of towers. Each carrier in each city runs a central office also known as
the Mobile Telephone Switching Office (MTSO). The MTSO is a switch that controls all the
operation system of a cellular system. When you power up a phone, it listens for special
frequencies (control channel) that the phone and tower use to talk to one another. If there is no
control channel, a phone displays a message no service because it knows it is out of range (The
Physics of Cell Phones, 2003).
A phone transmits a registration request so that the MTSO keeps track of the phone’s
location in the database. It is important for the MTSO to know the cell phone one is using when
the phone cell phone is about to ring. When MTSO gets a call, it tries to find the owner of the by
looking into the database to see which cell tower you are near. MTSO also chooses a frequency
pair that a phone will use in that cell to take the call. MTSO communicates with your phone over
the control channel to tell it what frequencies to use. When your phone and the tower switch on
those frequencies you are connected and talking. Lastly, as one move toward the edge of the cell
range, the cell tower notes a diminishing signal. The diminishing signal indicates that it is time
for the control channel to hand off you to the next cell tower. (The Physics of Cell Phones, 2003)
A cell phone is an amazing invention and there are several advantages to it. Over the
years, cell phones have changed the way society thinks, operates, and communicates. An
advantage of cell phones is that it provides its user with a wider opportunity to communicate by a
principle call frequency reuse. With this principle, the same frequency can be used by different
cells without creating interference from other cells. Frequency can be used over and over. Cell
phones operate within cell ranges and can switch cell ranges as the user moves around. Someone
using a cell phone can drive hundreds of miles and maintain a conversation during the entire
journey. This seems to be a more efficient and effective way to communicate. Another advantage
of cell phones is that they are small and easy to carry around. Modern digital cell phones can
process millions of calculations per second in order to compress and decompress the voice
stream. Cell phones have full duplex, meaning you can use one frequency for talk and other
frequency for listening. Both people on a cell phone can talk at once. The cell phone can
communicate on 1,664 channels or more. In addition, cell phones Time-Division Multiple
Access (TDMA) use a dual band. This means that it can operate in both 800 MHz and 1900 MHz
bands (The Physics of a Cell Phone, 2003).
Other advantages of cell phones are that you can store information, make task or to do
lists, keep track of appointments, and set reminders. Cell phones have a built-in calculator for
math, you can send, receive calls, get information for a variety of sources, such as, news,
entertainment, stock quotes, and play simple games. Cell phones have great influence in our
everyday life and are convenient to have around. Cell phones are a faster and more effective way
to transfer information. Some parents use cell phones to keep in contact with their children.
Other uses it for business and to keep in contact with loved ones. Cell phones have played a vital
role in bringing the world closer together.
According to the article “Understanding Wireless Telephone Coverage Areas”, there are
concerns about cell phones like many other electronic devices. Cell phones physically have nonrepairable internal parts that can corrode. For example if a cell phone gets wet, it may damage
the internal parts. Extreme heat in a car can damage the battery or the cell phone electronics and
extreme cold may cause a momentary loss of the screen display. Another disadvantage of cell
phones is that they do not have the ability to provide the callers location like a landline
telephone. If you do not know where you are, you cannot be found, if in trouble, on a cell phone.
The tower can be located, but the caller cannot because cells use base stations and towers to hand
off calls as the user moves from one location to another. In the tall building rage, it is hard to
gain service because the cell phone might not communicate well with the cell towers
(Understanding Wireless Telephone Coverage Areas,).
There are reasons to think that cell phones may cause cancer of the ear or brain tumors.
The more an individual uses cell phones and the greater the number of years used by the person,
the greater the risk of brain tumors. However, there has been doubt of phone companies that
there are no links to cancer even though the phones radiations do not have any connection to the
electrical activity to the brain (The Physics of cell phone, 2003).
Cell phones work through the ranges of cell tower which help in communicating with
people. These towers transmit radio waves from one cell phone to another. The range of the
towers also contributes to the access of cell phones service provider because as the phone is turn
on, the built in antennas communicate with the cell tower to gain network. Even though there are
advantages and disadvantages, the phones helps us to stay in contact with our love ones no
matter where they might be at the moment.
Reference:
"How Do Cell Phones Work?" Pong Making the Case for Cell Phone Radiation Protection RSS.
N.p., n.d. Web. 01 Dec. 2013. Retrieved from http://www.pongcase.com/blog/cellphones-work
"The Physics of Cell Phones." 03.04.07: The Physics of Cell Phones. N.p., n.d. Web. 01 Dec.
2013. Retrieved from http://www.yale.edu/ynhti/curriculum/units/2003/4/03.04.07.x.html
"How a Cell Phone Works." How a Cell Phone Works. N.p., n.d. Web. 01 Dec. 2013. Retrieved
from http://iml.jou.ufl.edu/projects/fall04/keith/Works.htm
"Guide Print Email." Understanding Wireless Telephone Coverage Areas. N.p., n.d. Web. 01
Dec. 2013. Retrieved from http://www.fcc.gov/guides/understanding-wireless-telephonecoverage-areas