It can be a scary world out there sometimes, and with the growing population of cell phone users, higher price tags and quick turn over it is no wonder cell phone theft is on the rise. Not just theft out of someones purse or when you leave it on a table. Straight grabbing it from your hand and running down the street theft. Blatant theft that is on the rise in places like Philadelphia. Last yea there were over 400 cell phone thefts reported on Philadelphia’s mass transit, up from 182 in 2008. What can you do to avoid being one of those numbers?
The term “unlocked” refers to GSM phones that have been universalized, or unlocked, so that they may be used on a variety of cellular phone companies that use GSM, as opposed to simply one. In areas like the United States where cellular carriers offer free or deeply discounted phones with cell plans, the phones are commonly locked so that they will not work with other carriers. Once unlocked, however, the phone should work with any GSM carrier once a SIM card has been inserted into phone.
GSM stands for Global Systems for Mobile Communication. GSM is the European standard, which has recently spread throughout the world. It is now the most popular system for mobile communication in the world. GSM technology also pioneered the SMS, or text message, which has changed the world of telecommunication as we know it.
For the average consumer, the key feature of GMS technology is its use of the SIM card. A detailed explanation of the SIM card is available in its own link on www.thebluedot.net; however, here is a brief explanation of the advantages of GSM Phones and SIM technology: The SIM card allows you to store your personal information and contact information on a removable card or “chip,” which can then be swapped from GSM phone to GSM phone. This meaning that you can transfer your account, your personal information, and all of your phone numbers to a different phone by simply removing your SIM card from one phone and placing it in another.
GSM uses a variation of Time Division Multiple Access (TDMA) and is the most widely used of the three digital wireless telephone technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. GSM networks operate in four different frequency ranges. Most GSM networks operate in the 900 MHz or 1800 MHz bands. Some countries in the Americas (including Canada and the United States) use the 850 MHz and 1900 MHz bands because the 900 and 1800 MHz frequency bands were already allocated.
GSM is the wireless telephone standard in Europe. GSM has over one billion users worldwide and is available in 190 countries. Since many GSM network operators have roaming agreements with foreign operators, users can often continue to use their mobile phones when they travel to other countries. Many of today’s GSM cell phones are “tri-band” or “world phones,” which means they can operate on three or more types of GSM frequency (i.e. American and European), allowing consumers to take advantage of this ability to use their own phone throughout many of the countries in the world.
Quite simple, the answer is no. When consumers see the term ‘unlocked’ in reference to cellular phones, it is most almost certainly being used to describe a GSM phone. To truly understand what an unlocked cell phone is, you need to have a basic knowledge of GSM and CDMA technology.
In the North American markets, and Latin American markets for that matter, GSM and CDMA are the two technologies that the dominant service providers use. What most easily distinguishes one from the other is that GSM carriers require phones that use SIM cards, and CDMA phones do not. Here is a brief breakdown on what technology the dominant carriers in the USA use: T-Mobile, AT&T/Cingular, and Nextel (Not Sprint/Nextel) use GSM technology, and Alltel, Cellular South, US Cellular, Sprint/Nextel, and Verizon use CDMA technology.
Because T-Mobile, AT&T/Cingular, and Nextel use GSM technology, their phones require SIM cards, which are portable memory chips that go into the back of these phones. When you sign up for a service plan with one of these service providers, your account registers to your SIM card and not to the actual phone (which is the case with CDMA phones). This technology allows you to remove, lets say, your T-Mobile SIM card from your T-Mobile phone and place it in any other T-Mobile phone and use that new phone with your account, instantly.
This is where “unlocking” phones comes into play. The phones that are produced for T-Mobile, AT&T/Cingular, and Nextel are programmed to only recognize their own company’s SIM cards. When one of these GSM phones is unlocked, however, it will then recognize any SIM card from pretty much any other GSM carrier. The ability to unlock GSM phones greatly benefits consumers who have service plans with GSM companies. Lets say that T-Mobile makes the same version of your AT&T phone, but the T-Mobile phone has a camera and yours does not. All you need to do is purchase an unlocked T-Mobile version, and you can now use that camera phone with your AT&T service.
GSM technology is arguably the worldwide standard as well, so purchasing an unlocked GSM phone makes world travel very convenient. Lets say that you are a T-Mobile customer with an unlocked cell phone, and you book a vacation to Puerto Vallarta, Mexico. Instead of paying international rate charges for using your phone in Mexico, you can simply purchase a pre-paid SIM card from a Mexican cellular company, like TelCel, and use it with your unlocked phone.
There are some features that work only with a phone designed for a specific carrier, though, so a consumer interested in purchasing an unlocked cell phone should definitely check with their service provider to make sure that the features that the need will work with an unlocked phone.






