An Introduction to Cell Phone Features

Nowadays，we find that today's mobile phone features provide users many more capabilities than only text messaging or voice calls.
General features
Cell Phones contain a standard set of services that allow phones of different types and in different countries to communicate with each other and are designed to work on cellular networks. But they can also support other features added by different manufacturers over the years:
1. Roaming that allows the same phone from China Wholesale to be used in multiple countries, offering that the operators of both countries have a roaming agreement.
2. Sending and receiving pictures and videos through MMS, and for short distances with for example，Bluetooth.
3. GPS receivers integrated or connected to cell phones, primarily to aid in dispatching emergency responders and road tow truck services. This feature is generally referred to as E911.
4. Send and receive faxes and data, access WAP services, and offer full Internet access using technologies e.g. GPRS.
5. Applications like a calendar, calculator, clock, alarm and a few games.
6. Features aimed toward personalisation, such as user defined and downloadable logos and ring tones, and interchangeable covers, which have helped in the uptake by the teenage market. Blackberry Phone content advertising has become massively popular but has also drawn a great deal of criticism. Usually one can choose between a vibrating alert, a ring tone, or a combination of both.
7. Push to talk, available on some mobile phones from Chinese Wholesaler, is a feature that allows the user to be heard only while the talk button is held, similar to a walkie-talkie.
Cell phones have recently gained reputations for their poor ergonomics，as a result of all these features packed into a tiny device. Their small size, plethora of features and modes, and attempts at stylish design may make them difficult and confusing to use.
Challenges in producing multi-mode phones
The special challenge involved in producing a multi-mode mobile is in finding ways to share the components between the different standards. Obviously, the Wholesale Bar Phone and display should be shared. otherwise it would be hard to treat as one phone. Beyond that, though, there are challenges at each level of integration. How difficult these challenges are depends on the differences between systems. When talking about IS-95/GSM multi-mode phones, such as, or AMPS/IS-95 phones, the base band processing is very different from system to system. This leads to real difficulties in component integration and so to larger phones.
Qwerty Keyboard and Quad Band mobile phones
Most mobile phone networks are digital and use the CDMA and GSM standard which operate at various radio frequencies. A Qwerty Keyboard Cell Phone operates across different standards whereas a Quad Band Cell Phone is a phone which is designed to work on more than one radio frequency. Some Qwerty Keyboard phones can operate on analog networks as well
Multi-band phones have been valuable to enable roaming whereas multi-mode phones helped to introduce WCDMA features without customers having to give up the wide coverage of GSM.
Data communications
Mobile phones are now heavily used for data communications such as SMS messages, browsing mobile web sites, and even streaming audio and video files. The main limiting factors are the size of the screen, lack of a keyboard, processing power and connection speed. Most Wholesale Slide Phone, which supports data communications, can be used as wireless modems, to connect computer to internet. Such access method is slow and expensive, but it can be available in very remote areas.
With newer smartphones, screen resolution and processing power has become bigger and better. Some new Wholesale Flip Phone CPUs run at over 400 MHz. Many complex programs are now available for the various smartphones.
Cameras
Most current phones also have a built-in digital camera, which can have resolutions as high as 8M pixels. This gives rise to some concern about privacy, in view of possible voyeurism. South Korea has ordered manufacturers to ensure that all new handsets emit a beep whenever a picture is taken.
Sound recording and video recording is often also possible. Most people do not walk around with a video camera, but do carry a phone. The arrival of video camera phones is transforming the availability of video to consumers, and helps fuel citizen journalism.
Vulnerability to Mobile viruses
They become more vulnerable to viruses which exploit weaknesses in these features as more complex features are added to phones. Even text messages can be used in attacks by worms and viruses. Advanced phones capable of e-mail can be susceptible to viruses that can multiply by sending messages through a phone's address book.
A virus may allow unauthorized users to access a phone to find passwords or corporate data stored on the device. Moreover, they can be used to commandeer the phone to make calls or send messages at the owner's expense.
Mobile phones used to have proprietary operating system unique only to the manufacturer which had the beneficial effect of making it harder to design a mass attack. However, the rise of software platforms and operating systems shared by many manufacturers such as Java, Microsoft operating systems, or Linux, may increase the spread of viruses in the future.
Bluetooth is a feature now found in many higher-end phones, and the virus Caribe hijacked this function, making Bluetooth phones infect other Bluetooth phones running the Symbian OS. In early November 2004, several web sites start providing a specific piece of software promising ring tones and screensavers for certain phones. Those who downloaded the software found that it turned each icon on the phone's screen into a skull-and-crossbones and disabled their phones, so they could no longer access contact lists or calendar or send or receive text messages. The virus has since been dubbed "Skulls" by security experts. The Commwarrior-A virus was identified in March 2005, and it attempts to replicate itself through MMS to others on the Wifi Cell Phone contact list. Like Cabir, Commwarrior-A also tries to communicate via Bluetooth wireless connections with other devices, which can eventually lead to draining the battery. The virus requires user intervention for propagation however.
Bluetooth phones are also subject to bluejacking, which although not a virus, does allow for the transmission of unwanted messages from anonymous Bluetooth users.