Cell Phone - Basic Info
Hi friends in this article let us discuss about one of the day to day technologies that naturally every people in the country use and this have become a necessity rather than that of a luxury item. Really, when it comes to technology Cell Phones is the only one which has a rapid development and almost every people starting from the rich people and those who work under them, everyone owns a cell, thanks to their low cast and also easy usage. The most important factor may be marketing, because next to coke and Pepsi advertisement, now we can see the advertisements of all the operators everywhere and this has attracted new user to get a SIM and a cell phone.
In India majority of the people use Nokia Company, when compared to that of Sony Ericsson and Motorola in countries like USA, but slowly other companies also, have established their market and so we can see that people start using cell phones made up of different companies. We can compare the cell phones with that of the CB radio (Citizen Band Radio) and that of the walkie talkie. Whenever we discuss about cell phones, the term which we often use is the radio, cells, frequency etc.
Cell phones use Duplex technology, when compared to that of the Simplex technology used in the Walkie Talkie. In simplex only one person can talk at a time and that is why in walkie talkie people used to say the word “Over”, when anyone finishes his/her talk and this is a indication that the next person can start to talk. This is the major disadvantage her a , because they use only one frequency, which means both the caller and call receiver will use the same frequency and so only one information can be transmitted at a single time.
Personal Communication Service (PCS) is a newer generation of the cellular radio technology and it uses a frequency of around 1900 MHz in the countries like United States. This is a digital technology, when compared to that of the older Analog technology like, AMPS. The main difference between analog and digital method is that in Analog, the audio is directly modulated into the carrier, whereas in the case of digital the analog audio is first converted into digitized samples at about 8000 samples/second. Then the samples are transmitted as I’s and 0’s and at the receiver side the reverse process is followed, where the receiver gets the information as the analog voice.
GSM is the latest digital technology which is used at present and in fact it is widely used in India and moreover in India we use a frequency of around 800 to 900 MHZ frequency bandwidth. When it comes to the coverage area cell phones have a wider range when compared to that of the walkie talkie or CB radios and this is due to the hexagonal cell structure used in the case of the cell phone and this enables a single tower in the cell, covering the entire cells.The reason why we use hexagon instead of circle is shown in the figure below.
The gap between the circles indictaes no coverage area.
The three most important codes used in the case of cell phones are
i) ESN: It is the Electronic Serial Number and it is a 32 bit number. It is naturally programmed into the phone, when they are manufactured by the company.
ii) MIN: It is the Mobile Identification Number. This is nothing but a ten digit number and naturally this is our cell phone number that a user use, and it is assigned by the operator and moreover it varies according to the different operator.
iii) SID: It is the System Identification Number and it is a 5 digit number assigned by the Federal Communications Commission (FCC).Actually FCC governs all the process involved that also involves the bandwidth allocation.So these are some of the basic information about the cell phones and we will discuss about the operation of a cell phone in the forth coming article.
Like it on Facebook, Tweet it or share this article on other bookmarking websites.