Sunday, November 10, 2019
How Cell Phones Work Essay
Cell phones are very interesting! Have you ever wondered how a cell phone works? Well we have. Cell phones have changed a lot since 1984. The first cell phone that came out was called the Dyna TAC8000X. (top left) It weighed 2 pounds! The brick only offered a half-hour of talk time for every charge. You could get this amazing device for $3,994! The man who invented this phone is Ruby Knopp. (top left) He also invented the newer modern Motorola Razor. (top middle) Some of the new cell phones provide an incredible amount of functions, like: store contact information, make tasks or to-do lists, keep track of appointments and set reminders, use the built-in calculator for simple math, send and receive e-mails, internet, play games, watch TV, send and receive text messages, integrate other devices such as PDAââ¬â¢s, MP3 players, and GPS receivers. One of the most interesting things about a cell phone is that it is actually a radio, an extremely sophisticated radio. The man who invented the telephone was Alexander Graham Bell (top right) in 1876. Wireless communication can trace its roots to the invention of the radio by Nikolai Telsa in the 1880s. When these two great technologies are combined it made the cell phone. People who needed mobile-communication devices had radio telephones in their cars. In the radio-telephone systems, there was one central antenna tower per city, and perhaps 25 channels available on the tower. In your car you needed a powerful transmitter. Not everyone could have a radio telephone because there were only 25 channels available per city. Each cell phone has a cellular system. A cellular system is a division of a city into small cells. Each cell has a base station that consists of a tower and a small building containing the radio equipment this allows widespread frequency reuse across a city, so that millions of people can use cell phones all at once. Each cell is typically sized at and covers about a 10 square miles radius. There is a requirement to have large number of base stations in a city of any size to make cell phone use function conveniently. A typical city can have hundreds of towers placed in certain regions to cover most of the areas completely. Central offices called the Mobile Telephone Switching Office (MTSO) handles all of the phone connections to the normal-based phone system, and controls all of the base stations in the region. Each carrier in each city runs a MTSO. All call phones have codes related to them. The codes are used to identify the phones owner, phone, and the service provider that they use. When a person first turns on their phone it listens for a System Identification Code (SID) on the control panel. A SID is a unique 5-digit number that is assigned to each carrier by the FCC. This is a unique frequency that the phone is based on. When you receive or make a call first, your cell phone radios the nearest tower. Next, a wire or fiber optic line carries the call down to the wireless access point connected to a multi-port switch. Then the call (along with many others) gets routed to a back haul ââ¬â usually down to an underground wire T1 or T3 line, but sometimes back up the mast to a powerful line-of-sight wireless microwave antenna (typically only used either when there isnââ¬â¢t a ground connection, or when the ground connection is poor.) The incoming call or data comes back from the back haul and up through the switch to the antenna, where it then hits your phone. If you are moving, then there is a hand off ââ¬â a new but more or less identical cell site transmits the data to your phone, once your phone check in. The benefits of having a cell phone is you can have long distance phone calls anywhere you are as long as you are in rang of a tower. Cell phones are great for emergencies. They have 911 panic buttons and GPS locations to find someone that is missing and has a GPS locator on their cell phone. Also if your in a panic and cant get your phone to type 911, most phones have a 911 panic button and it will call for help. For business people, the advantages are endless because cell phones have internet. Also being able to contact associates and clients is important in all situations. Important issues can be solved at anytime, regardless of time zones and locations. Also cell phones can be used as legal evidence standards. Cell phones and their records have been used in court rooms as evidence, and are also used be law enforcement officers and investigators for recording and evidence. The disadvantages of having a cell phone is they cost a lot. They can range from $40 to over $300. You can also have additional costs for apps, music, games, and many more things. The only way of getting out of your cell phone plan is to pay a termination fee of &150 or more. Cell phones can be big distractions. They can ring during a movie, music concerts, plays and other areas where silence is required. Also during driving, because cell phone use while driving has caused so many accidents that five states had banned calls while driving and 12 states had prohibited text messaging while driving. 21 States had prohibited any use of cell phones while driving (except for emergencies) including Washington state. Cell phones can also have lack of privacy because cell phones provide no audio feedback through the ear piece. Some people talk much louder with cell phones then they do on land lines. This exposes the people around them to their conversations. Cell phones emit low levels of RF (radio frequency) radiation. Large amounts of this energy can heat and damage tissue, especially around the eyes and testicles, which do not have enough blood flow to carry away such heat. This is also concern that cell phones might cause cancer, headaches, sleeping problems, and memory loss. Brian, Marshall. ââ¬Å"How Cell Phones Work.â⬠HowStuffWorks ââ¬â Learn How Everything Works! 2011. Web. 27 Jan. 2011. . ââ¬Å"Cell Phone and Wireless Service Planing Guide.â⬠Cell Phone and Wireless Service Plan Buying Guide. 2010. Web. 27 Jan. 2011. . ââ¬Å"Disadvantages of Cell Phones.â⬠EHow | How To Do Just About Everything! | How To Videos & Articles. 14 Apr. 2010. Web. 27 Jan. 2011. . ââ¬Å"How Cell Phones Work.â⬠Cell Phones. 2008. Web. 27 Jan. 2011. .
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