Posts Tagged ‘ Cellular ’

No one doubts that cell phone is one of the most used consumer electronics worldwide. But have you ever asked yourself how does a cell phone work? What is a cell phone?
The amazing fact about a cell phone is that it is a radio – a very special one. The gurus in the line are Bell (1876), Tesla (1880) followed by Marconi and Bose (late 19th century). It is known that the concept of cell phone was produced by Bell Laboratories with the permission of FCC (Federal Communication Commission), and had everything to do with broadcasting and sending a radio message out over the airwaves.
In cell phone technology cells divide the city, allowing for the facility to be frequently reused throughout the city. Millions can simultaneously avail of it.
In devices that are half-duplex (walkie-talkies and CB radios) two communicators use a single frequency. This means that at a single point of time only one can talk. On the other hand a cell phone being a full duplex tool has two frequencies: one for talking and the other for listening. Thus a real-life conversation can take place. Cell phones glide through 1,664 channels whereas the walkie-talkie group has to be content with only 40. The walkie-talkie and the CB radio respectively reaches out to 1 mile and 5 miles but the cell phones, because of their ability to switch from cell to cell can cover incredible distances, even while driving at top speed. Each cell is approximately 10 square miles.
The cells are usually depicted as hexagons. The unique frequency tiers avoid all possibilities of cross connections. Generally a carrier of cell phone can avail of 832 radio frequencies in a city. Each cell phone uses 395 voice channels (per carrier), that is 56 voice channels per cell. It means 56 persons can simultaneously say hello on the phone. In digital transmission technology the number of channels increases even further. For each cell phone 168 channels is available.
The distinctiveness about cell phones is their low-power transmitters. Most use 2 strengths: 0.6 watts and 0.3 watts. In comparison it is 4 watts for CB radios. The advantage of this is that it can be frequently reused consuming less power. Cell phones are battery operated. The lower the power the smaller the battery. This makes the set handy and light.
For cellular technology a city requires a good number of base stations. This can run into some hundreds of towers. But because of the huge number of users costs per head remain very low. Each carrier has one centre called MTSO or Mobile Telephone Switching Office. Its work is to see to all the connections.
Cell phones each have codes, which enable identification of the phone, its user and its server. When someone tries to reach a phone the first thing is to locate the SID (system identification code) on the control channel, that is find out if the phone is within range or not. A message relays no-service when it is out of range. But when the SID is received then the next step is to find out whether the call is within its own home zone or not. The phone also tracks the location of the phone called on a database. Thus the MTSO knows the cell of the called number and caller. Communication is transmitted through the control channel and it is this link that activates the phone being called and calling.
These are the facts of a cell phone as explained for a layman. It is always advisable to know at least the basics of a cell phone since it has become an integral part of our life.

Cell phone is a wireless, portable, long-range, electronic telephone, which during travel can seamlessly change antenna connections, from one radio reception cell to another radio reception cell, without dropping or losing the ongoing call.
Besides the standard voice function of a telephone, latest cell phones have features such as SMS for text messages, MMS for multimedia messages, radio, games, internet connectivity for email, browsing, blogging, music (MP3) playback, memo recording, built-in cameras and camcorders, ringtones, personal organizers, Push-to-Talk (PTT), Bluetooth and infrared connectivity, call registers, streaming video, downloading video, video call, and also serve as wireless modems for PCs that can be connected to the Internet.
The power in a cell phone is obtained from rechargeable batteries, which can be recharged from the mains, a USB port or a cigarette lighter port in an automobile. Nickel Metal Hydride were the most common types of batteries, which due to the “memory effect” (the user can recharge only when the entire battery is drained off) were replaced by Lithium-Ion batteries, which did not suffer from any memory effect.
Cell phones came into existence because of the invention of hexagonal cells in 1947, for the base stations by Bell Labs engineers at AT&T. This was further developed during the 1960s by Bell Labs. During a call, the channel frequency could not be changed automatically from one cell (base station coverage area) to another cell (base station coverage area) as the person traveled from the area of one cell to the area of another cell. Amos Joel of Bell Labs invented a breakthrough invention and called it as the `call handoff` by which the channel frequency could be changed automatically from one cell to another cell, during the same call, as the mobile user traveled from one cell to another cell. Due to their heavy construction, these phones were used mainly in automobiles.
The first practical cell phone in a non-vehicle setting, and which could be handheld, was invented by Martin Cooper, the General Manager (Communications Division) of Motorola, who made the world`s first handheld cell phone call on April 3, 1973.
The technology by which the cell phone works depends on the mobile phone operator; however, all of them use electromagnetic radio waves, which are in touch with a cell site (base station). The base station is composed of several antennas which are mounted on a pole, tower, or building. Cell sites are spread at a distance of 5 to 8 miles (approx. 8 to 13 km) from each other. The low power transceiver from the cell phone transmits the voice and data to the nearest cell site. During movement, the cell phone will “handoff” the information to other cell site. Mobile phone operators use many technologies to maintain the smooth stream of digitized data from the cell phone to the cell site and vice versa.
The wireless telephone technologies are grouped under heads known as generations, starting from zero generation or 0G. The current generation going on is 4G; however, there are old cell phones that still operate on 1G, 2G, and 3G technologies. The wireless telephone technologies used in each generation are as given below:
0G: PTT, MTS, IMTS, AMTS, OLT, MTD, Autotel/PALM, ARP
1G: NMT, AMPS/TACS/ETACS, Hicap, CDPD, Mobitex, DataTac
2G: GSM, iDEN, D-AMPS, IS-95/cdmaOne, PDC, CSD, PHS, GPRS, HSCSD, WiDEN, CDMA2000 1xRTT/IS-2000, EDGE (EGPRS)
3G: W-CDMA, UMTS (3GSM), FOMA, TD-CDMA/UMTS-TDD, 1xEV-DO/IS-856, TD-SCDMA, GAN (UMA), HSPA, HSDPA, HSUPA, HSPA+, HSOPA
4G : UMB, UMTS Revision 8 (LTE), WiMAX
Frequency bands: SMR, Cellular, PCS
The impact of cell phone usage on human health has been of considerable worldwide concern. Research studies in Copenhagen, from the Danish Institute of Cancer Epidemiology, the National Cancer Institute, and the Institute of Cancer Research, do not establish any link between cancer and cell phone usage. However, an intergovernmental agency IARC (International Agency for Research on Cancer) forming part of the World Health Organization of the United Nations, undertook a study of 4,500 users and found a statistically significant link between cell phone usage and tumor frequency. Further research is going on.
Cell phone usage and driving is a common worldwide phenomenon. Some jurisdictions have banned usage of hand-held phones during driving, but allowed the hands-free fashion of cell phone usage while driving. However, studies have found out that the distraction is caused by the conversation itself; hence, both hand-held and hands-free cell phones contribute towards road traffic accidents. Further studies on cell phone usage and driving are going on.
Nokia Corporation is currently the world`s largest manufacturer of cell phones. Other notable cell phone manufacturers, in alphabetical order, are 3G, Audiovox (now UT Starcom), Benefon, BenQ-Siemens, Fujitsu, High Tech Computer Corporation (HTC), Kyocera, LG Mobile, Motorola, NEC, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericsson, T&A Alcatel, Toshiba, and Verizon.

Cell phone has become one of the basic essentials among the techno-savvies irrespective of their profession and life style. Most people are using cell phone in place of a landline connection primarily due to their portability.
However, the handy device needs proper care and attention for consistency with its performance. When it comes to cell phone performance, the first thing that comes to our mind is the battery of a cell phone which forms the vital part of the device.
The functionality of the cell phone battery can be decided from two aspects- the interval between the charges and the life of the battery on a whole.
To increase the life of the battery between charges:
The simplest way is to switch the cell off when you do not want to receive a call, for instance at nights or after business hours or at times when your cell phone is out of coverage area. In an area where there is poor or no signal the cell may search for a better connection consuming much battery power.
Use ring tones of your cell phone instead of using the vibration mode and try to keep the volume as low as possible. The vibrate function eats up much battery power making the battery run down of power faster.
Flash photography, connection to internet and Bluetooth device drain the battery quicker. Hence, switching off the unnecessary features when not in use can save the power of your cell phone battery. WiFi and GPS enabled cell phone are also more prone to higher battery consumption and should be turned off.
Well, limiting the talk time over cell phone is healthy for both the battery and you as well. Longer call results in more consumption of battery.
Use the GSM mode of the cell phone in stead of using it in 3G/Dual mode.
Turn off the back light of your cell phone.
Extend the Life of Cell phone Battery:
The new battery should be initialized properly. Charge the new battery completely before installing it into the cell phone.
Keep the cell phone in room temperature as much as possible. Exposure to excessive heat may deter the battery to last long and perform properly. Moreover, try to keep the battery cool.
It is very important to charge the cell phone battery properly according to its type. The nickel-based batteries need to be discharged completely once in every two to three weeks and then recharged again. The lithium ion batteries should be discharged till the low battery warning. Recharge it before the battery is completely drained out. However, it is important to use cell phone charger meant for the type of battery.
Storing the battery properly is another vital thing. Store it away from any metal and make sure that the cell phone battery is not exposed to moisture.
The battery contact should be cleaned in regular time interval as they accumulate dirt over time.
No matter how much care you take of your cell phone battery, it is sure to die and decrease its performance sooner or later. You can ask the manufacturer to get it refurbished. Some of the cell phones have a `Battery Save` option that can be turned on to increase the life span of the battery. Ensure that the temperature inside a car is not high if you are using a car charger to recharge your cell phone.
When you are using delicate gadgets like cell phone, it is essential to take proper care of it. The cell phone battery is one of the delicate parts of the cell phone and its performance depends largely on the way you take care of it. However, charging the cell phone in a proper way is the important aspect of battery care that will ensure prolonged life for your cell phone battery.

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Cell phones, also commonly known as mobile phones, are electronic devices which are used for communication purposes. Voice or data is communicated through these cell phones over a network of stations. Cell phones have all the features of a general telephone and also have various specialized features.
History and Overview:
Cellular Network was initially proposed by Bell Labs in the year 1947. He was the first person to establish cellular network in the year 1970 in Chicago. After that Japan launched the first mobile phone service in the year 1978. With the advent of time, there has been tremendous improvement in the mobile phone technology and in the year 1996, mobile phone giant Nokia launched its first multi use smart phone Nokia communicator which had the facility of internet connectivity and email services.
Cell phone handsets:
Cell phone handsets are the devices which are used for communication purposes. There are a wide rang of handsets with varying features which are being produced by manufacturers worldwide. Currently, Nokia is holding the largest chunk of market share of cell phones and is regarded as world`s largest manufacturer of mobile phone handsets.
Other major names in the list of cell phone manufacturers include Motorola, Sony Ericsson, Samsung, LG etc. These cell phones work on rechargeable batteries which obtain power from electric current, solar, dynamo, car battery charger etc. Before using a handset it needs to be activated with a SIM card provided by a mobile phone service provider who will also allot a unique number for your phone.
Features of Cell Phones:
Apart from having almost all the features of a normal telephone the cell phone also has various other unique features which make them very useful in today`s busy life schedule. These features include music, mp3 player, in built high pixel still and movie camera, personal organizer functions, Internet connectivity with browsing and emailing facility, different ring tones both inbuilt and with a facility to download, blue tooth and infra red connectivity etc.
Cell phones are also able to receive and send faxes if it is connected to a computer. Apart from Short messaging service (SMS), Cell phones are also enabled to send pictures and videos through Multimedia messaging service (MMS).
Uses of Cell Phone:
Cell phones are now widely used by both civilians and government agencies. Government agencies use mobile phones extensively for law enforcement, military purposes, disaster management etc. In the usage of cell phones, you must be particular about maintaining the culture and customs.
It is not decent to use your mobile phone while sitting in an important meeting. It is desirable that you switch off your phone when in any funeral or libraries or cinema halls etc. Most schools and colleges have restricted the use of mobile phones in their premises.
Beliefs about health and environment hazards and safety concerns:
Several concerns regarding human health resulting as an impact of mobile phone usage has been raised from time to time. There have been dermatological concerns such as occurrence of rashes on ears and cheeks of the users, hearing problems in the ear, heart problems concern etc.
Environmental hazards such as electronic waste and safety hazards in usage of the cell phone have been of great concern. There has been an increase in accidents by drivers while talking on cell phones. Road accidents while using a cell phone are on an increase. High rise towers of the cellular networks are also a cause of concern to flying aircrafts and birds.
The tremendous benefits of connectivity in all locations wherever you are have outshined the disadvantages and health concerns of cell phone and the number of cell phone users is rising day by day.

Cell phone has brought the world much closer. It does not matter on which part of world you live, you can get in touch with your loved ones through this amazing device. It is small in size, smart and slick in look, portable.
Though it was originally designed to eliminate the limitations of telephone, but gradually cell phone manufacturers come up with models containing many advanced features like MP3 player, camera, video recording facility, and 3D-games. Even you can access the Internet from your cell phone. In fact, the services provided by SMS, MMS and WAP have been popularized by cell phone. It is no wonder then why the use of cell phones has increased many folds in the last couple of years. According to one survey, every eight out of ten people own a cell phone in the USA.
Have you ever wondered how this cell phone works? You can say cell phone is more or less like a sophisticated radio. Cell phone is a full-duplex device which means one frequency is used for talking and another for listening so that both people can talk simultaneously. Earlier first generation mobile technology (1G) was used for Analog model of cell phone and had only 56 channels.
With the advent of second generation mobile technology (2G) the number of channels gradually increased. Now-a-days, a cell phone can communicate on 1,664 channels or more. The range of cell phone depends on its battery or cell power. You can talk hundred miles of your journey if your cell supports that range. The range also depends upon the tower locations. Cell phone tower is a steel pole containing equipments to send and receive the frequency.
Wondering what your cell phone can do for you? Here is the list:
You can store and retrieve information from your cell phone;
You can set of your important appointments and reminders through cell phone;
You can send and receive text, multimedia messages from your cell phone;
You can access internet, send Email through your cell phone;
You can watch movie, play 2D or 3D games through your cell phone;
You can enjoy listening music through the MP3 player of your cell phone;
You can integrate your cell phone with GPRS service facility to download music from internet;
You can share your favourite music among your friends through the Bluetooth technology of your cell phone;
Some models of cell phone also act as a compass guide so show you the exact geographic location (altitude, longitude wise). They come across quite handy especially for people who are on expeditions.
Like any other electronic devices, cell phone also has got its own share of problems. Doctors have warned against use of cell phones over a long time as it can lead to cancer and liver related problem due to the strong radiation emitted from this electronic device. Now research has shown that prolong use of cell phones can result in infertility problem in women.
Scientists have also examined a significant reduction in sperm count among men who use cell phone for longer period. Talking or listening to music for long time can lead to loss of hearing as well. Children should not be allowed to use cell phones much as its radiation can lead to different kind of health hazards.
Certain precautions should be taken while using cell phone. For instance, you should never use your cell phone when there is strong lightening or thundering. Never let your cell phone gets wet and do not use it with wet hands as there is chance of corrosion to the non-repairable internal parts. In case it does get wet, make sure it to be completely dry before switching it on. If you take care of these couple of things your call phone`s longevity will be increased.