What are Unlocked Cell Phones?

Some cell phones are designed to use a Subscriber Identification Module (SIM) card, or microchip that stores subscriber data. The SIM card is issued by a carrier and provides cell service by activating any phone into which it is inserted. A locked phone, however, will only recognize a SIM card from a particular carrier. If the cell phone is unlocked, it will recognize a SIM card from any carrier. The "lock" is a software setting that keeps the cell phone "loyal" to one carrier. In areas like the United States where carriers offer free or deeply discounted phones with cell plans, the phones are commonly locked so that they will not work with other carriers. Carriers claim this is necessary to subsidize the cost of the phones. After a period of time, a carrier might agree to unlock the phone upon request, perhaps charging a fee. However, due to proprietary settings sometimes installed in locked handsets, the phones don't always function correctly with other carriers, even once unlocked. From the viewpoint of the consumer, the practice of carriers locking phones and using proprietary settings defeats many of the benefits of SIM handsets. Complaints led to a class action suit filed in California in June 2004 by American watchdog group Foundation for Taxpayer and Consumer Rights (FTCR). Ideally phones should be left unlocked or at least unlocked after the initial contract expires. One way to get an unlocked phone without proprietary settings is to buy it new from a third party vendor in its original, unlocked state. The downside is that the price is commonly close to full retail. Some consumers might find it tough to dish out big bucks for a phone that they can get for free with a plan. The advantage is that the third party unlocked phone should work equally well with any carrier that uses SIM cards. Unlocked cell phones are in such demand that third party services will unlock your cell phone for a fee. This doesn't guarantee the phone will always work correctly, as proprietary settings might remain. There are also hacking instructions online to unlock many models of phones, but a phone that is unlocked improperly can be rendered inoperable. Carriers operating on the GSM network use SIM cards. In the United Sates, this includes Cingular Wireless, now one with AT&T Wireless, and T-Mobile. Carriers that use the competing CDMA network do not yet use card-enabled phones. These carriers include Sprint PCS, Verizon and Virgin Mobile. The CDMA equivalent of the SIM card — the R-UIM — will be used by these carriers in the future. R-UIM cards are already in use in some parts of Asia.

What are CDMA Cell Phones?

CDMA uses a “spread-spectrum” technique whereby electromagnetic energy is spread to allow for a signal with a wider bandwidth. This allows multiple people on multiple cell phones to be “multiplexed” over the same channel to share a bandwidth of frequencies. With CDMA technology, data and voice packets are separated using codes and then transmitted using a wide frequency range. Since more space is often allocated for data with CDMA, this standard became attractive for 3G high-speed mobile Internet use. The CDMA standard was originally designed by Qualcomm in the U.S. and is primarily used in the U.S. and portions of Asia by other carriers. Sprint, Virgin Mobile and Verizon Wireless use CDMA while T-Mobile and AT&T use GSM. While CDMA and GSM compete head on in terms of higher bandwidth speed (i.e. for surfing the mobile Web), GSM has more complete global coverage due to roaming and international roaming contracts.

GSM technology tends to cover rural areas in the U.S. more completely than CDMA. Over time, CDMA won out over less advanced TDMA technology, which was incorporated into more advanced GSM.

What is the Difference between a Triband and Quadband phone?

It really depends on the type of service you need. The more places you need to be able to use your cell phone, the more frequencies you need. If you need service internationally or globally, you will need a greater number of frequencies than someone who only uses a phone close to home. In other words, between triband and quadband, the latter would be the better option for service that covers more area. For phones that are only going to be used locally or regionally, triband should be sufficient.
Service can be provided utilizing six different frequencies, ranging from 450 to 2100 megahertz, yet the lowest and the highest are not typically germane to the question concerning triband and quadband phones. Most triband and quadband phones operate using a combination of 850, 900, 1800, 1900 MegaHertz, with quadband utilizing each of them.
The biggest difference between triband and quadband phones may be the location from which service originates. In Europe and Asia, a good example is a cell phone service provider that equips its phones with the 900 and 1800 MHz frequencies to cover local use but also adds the1900 frequency to allow for roaming. In North America, it may be basically the opposite. North American cell phone service providers generally utilize the 850 and 1900 MHz frequencies and 1800 for use outside the continent. 

What is 3G Technology?

3G is the third generation of telecommunication hardware standards and general technology for mobile networking, superseding 2.5G. It is based on the International Telecommunication Union (ITU) family of standards under the IMT-2000.[1]

3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephone, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver data rates up to 14.4 Mbit/s on the downlink and 5.8 Mbit/s on the uplink.
Unlike IEEE 802.11 networks, which are commonly called Wi-Fi or WLAN networks, 3G networks are wide-area cellular telephone networks that evolved to incorporate high-speed Internet access and video telephony. IEEE 802.11 networks are short range, high-bandwidth networks primarily developed for data.

What is TFT screen ?

A TFT monitor uses thin-film transistor technology for the ultimate LCD display. LCD monitors, also called flat panel displays, are replacing the old style cathode ray tubes (CRTs) as the displays of choice. Nearly all LCD monitors today use TFT technology.
The benefit of a TFT monitor is a separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display, as the image is re-painted or refreshed several times per second.
Prior to TFT, passive matrix LCD displays could not keep up with fast moving images. A mouse dragged across the screen, for example, from point A to point B, would disappear between the two points. A TFT monitor can track the mouse, resulting in a display that can be used for video, gaming and all forms of multimedia.
A typical 17-inch TFT monitor has about 1.3 million pixels and 1.3 million transistors. That leaves a significant chance for a malfunctioning transistor or two on the panel. Upon delivery, a TFT monitor can have "dead pixels" for this reason. A dead pixel is a pixel whose transistor has failed, thereby creating no display image. On a solid black background, dead pixels will stand out as tiny dots of red, white or blue. Most manufacturers will not replace a TFT monitor that has less than 11 dead pixels. Often, a TFT monitor won't have any dead pixels —- always the hope for any buyer, though dead pixels are not noticeable unless located in a critical position on the screen.

What is QWERTY keyboard?

Pronounced kwer-tee, refers to the arrangement of keys on a standard English computer keyboard or typewriter. The name derives from the first six characters on the top alphabetic line of the keyboard.
The arrangement of characters on a QWERTY keyboard was designed in 1868 by Christopher Sholes, the inventor of the typewriter. According to popular myth, Sholes arranged the keys in their odd fashion to prevent jamming on mechanical typewriters by separating commonly used letter combinations. However, there is no evidence to support this assertion, except that the arrangement does, in fact, inhibit fast typing. With the emergence of ball-head electric typewriters and computer keyboards, on which jamming is not an issue, new keyboards designed for speed typing have been invented. The best-known is called a Dvorak keyboard. Despite their more rational designs, these new keyboards have not received wide acceptance.
What is difference between user memory and internal memory in cell phones?
User memory is the Total memory that can be used for storing user data viz. contacts, messages, photos, ring tones, videos etc
whereas internal memory is the memory used for storing the cell phones operating applications etc and not accessible to the user (reserved for the Phones applications).
However, in the literature used for marketing, the term internal memory is also used to describe the inbuilt user memory in a phone with an option to add memory cards. This added memory is referred as external or expandable memory.

What is Memory Stick Micro M2 ?

Sony released a new Memory Stick format on February 6, 2006. The Memory Stick Micro (M2) measures 15 × 12.5 × 1.2 mm—roughly one-quarter the size of the Duo, around the size of a fingernail—with 128 MB, 256 MB, 512 MB, 1 GB, 2 GB, 4GB, 8GB, 16GB capacities, with a theoretical limit of 32 GB. memory stick micro m2 fit to all the new Sony Ericsson phones that have memory slot, please check in detailed specs for maximum memory card capacity.

 

What is MicroSD card (TransFlash)?

microSD is a format for removable flash memory cards. The SD stands for Secure Digital. It is commonly used in cellular phones, but also in handheld GPS devices, portable media players, digital audio players, expandable USB flash memory drives, and for Nintendo DS flashcards, along with digital cameras.TransFlash and microSD cards are the same (each can be used in devices made for the other), except that microSD adds support for SDIO mode, enabling non-memory cards like Bluetooth, GPS, and Near Field Communication devices.[2]

A point of confusion can come from the difference in the microSD and the newer microSDHC format. The SD and SDHC share a similar form factor, but not all devices are compatible with the newer high capacity format. This is even true with devices that have been developed by SanDisk such as their e200 series of MP3 players.  Using 3rd party firmware however, SDHC reading capabilities can be possible, but an external writer is still requiredplease check in in deatailed specs for maximum memory card capacity.

What is GPRS?

General Packet Radio Services (GPRS) is a packet-based wireless communication service that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users. The higher data rates allow users to take part in video conferences and interact with multimedia Web sites and similar applications using mobile handheld devices as well as notebook computers. GPRS is based on Global System for Mobile (GSM) communication and complements existing services such circuit-switched cellular phone connections and the Short Message Service (SMS). In theory, GPRS packet-based services cost users less than circuit-switched services since communication channels are being used on a shared-use, as-packets-are-needed basis rather than dedicated to only one user at a time. It is also easier to make applications available to mobile users because the faster data rate means that middleware currently needed to adapt applications to the slower speed of wireless systems are no longer be needed. As GPRS has become more widely available, along with other 2.5G and 3G services, mobile users of virtual private networks (VPNs) have been able to access the private network continuously over wireless rather than through a rooted dial-up connection. GPRS also complements Bluetooth, a standard for replacing wired connections between devices with wireless radio connections. In addition to the Internet Protocol (IP), GPRS supports X.25, a packet-based protocol that is used mainly in Europe. GPRS is an evolutionary step toward Enhanced Data GSM Environment (EDGE) and Universal Mobile Telephone Service (UMTS).

What is HSCSD?

HSCSD (High Speed Circuit Switched Data) is a specification for data transfer over GSM networks. HSCSD utilizes up to four 9.6Kb or 14.4Kb time slots, for a total bandwidth of 38.4Kb or 57.6Kb. 14.4Kb time slots are only available on GSM networks that operate at 1,800MHz. 900Mhz GSM networks are limited to 9.6Kb time slots. Therefore, HSCSD is limited to 38.4Kbps on 900Mhz GSM networks. HSCSD can nly achieve 57.6Kbps on 1,800Mhz GSM networks. HSCSD was an enhancement to to earlier CSD (Circuit Switched Data) standard.EDGE (Enhanced Data-Rates for GSM Evolution) enabled GSM networks are able to implement ECSD (Enhanced Circuit Switched Data), an enhanced version of HSCSD. ECSD increases the bandwidth of each timeslot to 48Kb and allows the use of eight timeslots, which gives a total transmission speed of 384Kbps.Both HSCSD/ECSD and GPRS are likely to eventually be phased out in favor of UMTS, which is a packet switched technology with speeds up to 2Mbps.

What is EDGE?

EDGE (Enhanced Data GSM Environment) is a faster version the Global System for Mobile (GSM) wireless service designed to deliver data at rates up to 384 Kbps and enable the delivery of multimedia and other broadband applications to mobile phone and computer users. The EDGE standard is built on the existing GSM standard, using the same time-division multiple access (TDMA) frame structure and existing cell arrangements. Ericsson notes that its base stations can be updated with software.
EDGE became commercially available in 2001. It is regarded as an evolutionary standard on the way to Universal Mobile Telecommunications Service (UMTS).

What is Wireless LAN?

A wireless LAN (WLAN) is a wireless local area network that links two or more computers or devices using spread-spectrum or OFDM modulation technology based to enable communication between devices in a limited area. This gives users the mobility to move around within a broad coverage area and still be connected to the network.For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities.

What is Symbian OS?

Symbian OS is a proprietary operating system designed for mobile devices, with associated libraries, user interface, frameworks and reference implementations of common tools, developed by Symbian Ltd. It is a descendant of Psion's EPOC and runs exclusively on ARM processors although a non-productized x86 port exists.On 24 June 1998, Symbian Ltd. was formed as a partnership between Ericsson, Nokia, Motorola and Psion, to exploit the convergence between PDAs and mobile phones. Symbian was previously owned by Nokia (56.3%), Ericsson (15.6%), Sony Ericsson (13.1%), Panasonic (10.5%) and Samsung (4.5%). Ten years later to the day, on 24 June 2008, Nokia announced that they intended to acquire all shares that they did not already own.[2] The acquisition was of €264 million, or $410 million.[3] On 24 June 2008 the Symbian Foundation was announced with the aim to "provide royalty-free software and accelerate innovation".

What is Window Mobile?

Windows Mobile is a compact operating system combined with a suite of basic applications for mobile devices based on the Microsoft Win32 API. Devices that run Windows Mobile include Pocket PCs, Smartphones, Portable Media Centers, and on-board computers for certain automobiles. It is designed to be somewhat similar to desktop versions of Windows, feature-wise and aesthetically. Additionally, third-party software development is available for Windows Mobile. Originally appearing as the Pocket PC 2000 operating system, Windows Mobile has been updated several times, with the current version being Windows Mobile 6.1 and a future 6.5 release planned for release toward the end of 2009.

What is Blackberry OS?

BlackBerry OS is the proprietary software platform made by Research In Motion for their BlackBerry line of handhelds. It provides multi-tasking, and makes heavy use of the device's specialized input devices, particularly the thumbwheel. The OS provides support for MIDP 1.0 and WAP 1.2. Previous versions allowed wireless synchronization with Microsoft Exchange Server's e-mail and calendar, as well as with Lotus Domino's e-mail. The current OS 4 provides a subset of MIDP 2.0, and allows complete wireless activation and synchronization with Exchange's e-mail, calendar, tasks, notes and contacts, and adds support for Novell GroupWise and Lotus Notes.Third-party developers can write software using these APIs, and proprietary BlackBerry APIs as well, but any application that makes use of certain restricted functionality must be digitally signed so that it can be associated to a developer account at RIM. This signing procedure guarantees the authorship of an application, but does not guarantee the quality or security of the code.

What is SMS?

The acronym SMS stands for short message service. SMS is also often referred to as texting, sending text messages or text messaging. The service allows for short text messages to be sent from one cell phone to another cell phone or from the Web to another cell phone.
Including spaces, text messages can’t exceed 160 characters. Some cell phones have full keyboards for faster texting whereas others require numbers to be tapped multiple times to achieve a particular letter. While the bulk of a cell phone bill always is its voice minutes, text messages are either included in the voice plan or are added as an extra cost. SMS messaging is used by billions of people and is the most pervasive use of data on mobile phones.

What is MMS?

Multimedia Messaging Service (MMS) is an upgraded version of the SMS (Short Messaging Service) through which you can send and receive multimedia messages such as texts, pictures, video clips, audio clips, etc., with any other compatible cell phone. It's an advanced messaging service that lets users send multiple media in one single message to one or more recipients.

What is WAP?

Wireless Application Protocol, a secure specification that allows users to access information instantly via handheld wireless devices such as mobile phones, pagers, two-way radios, smartphones and communicators. WAP supports most wireless networks. These include CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, iDEN, TETRA, DECT, DataTAC, and Mobitex. WAP is supported by all operating systems. Ones specifically engineered for handheld devices include PalmOS, EPOC, Windows CE, FLEXOS, OS/9, and JavaOS. WAPs that use displays and access the Internet run what are called microbrowsers--browsers with small file sizes that can accommodate the low memory constraints of handheld devices and the low-bandwidth constraints of a wireless-handheld network. Although WAP supports HTML and XML, the WML language (an XML application) is specifically devised for small screens and one-hand navigation without a keyboard. WML is scalable from two-line text displays up through graphic screens found on items such as smart phones and communicators. WAP also supports WMLScript. It is similar to JavaScript, but makes minimal demands on memory and CPU power because it does not contain many of the unnecessary functions found in other scripting languages. Because WAP is fairly new, it is not a formal standard yet. It is still an initiative that was started by Unwired Planet, Motorola, Nokia, and Sony Ericsson.

What is IC chip?

In electronics, an integrated circuit (also known as IC, microcircuit, microchip, silicon chip, or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface of a thin substrate of semiconductor material. Integrated circuits are used in almost all electronic equipment in use today and have revolutionized the world of electronics.A hybrid integrated circuit is a miniaturized electronic circuit constructed of individual semiconductor devices, as well as passive components, bonded to a substrate or circuit board.
How long does it take to fully charge a battery?
The time required to charge a battery depends on the battery type, the capacityof the battery, and the type of charger being used.  A higher mAh battery will take longer to charge than a lower mAh battery.  In general, it will take 3-4 hours to "rapid charge" a battery to the 80% level, and an additional 8 hours to “slow or trickle” charge a battery to the 100% level.  A good approach is to charge your battery overnight for about 12 hours.

Will overcharging my Battery hurt it?

Yes, overcharging a battery causes it to overheat and can result in damage to the battery, causing degraded performance and eventual failure.  As a general rule, do not charge a battery for more than 24 hours.

How long will a battery last?

In general, the life of a regularly used battery is between 300 and 500 charge/discharge cycles.  Depending on the battery, this translates into a 1-to-2 year timeframe.  As a battery nears the end of its productive life (typically considered 50% of its original capacity), the talk and stand-by times of the battery will be noticeably shorter.  It is interesting to note that a Lithium-ion battery will, over it's useful lifetime, maintain more of a full capacity charge and then "die" rather suddenly; a NiMH battery will demonstrate a more gradual decline in performance as it nears the end of it's productive life.