[Editor's Note: Used unlocked cell phones have many advantages over phones that are tied to a particular carrier. Not only can you move from network to network without any hassles, but you can also get them cheap! Head over to eBay and check out a ton of listings for used and refurbished unlocked cell phones.]

Mobile phones have become a necessity for everyone in today’s world. There are many cell phones available in the market. Some of these are locked while others are unlocked. But what exactly are unlocked cell phones? How do they work? What are their benefits? To know more, read on…

Many of us must be aware of the concept of unlocked cell phones. These are getting more and more common and an increasing number of people are using them nowadays. With unlocked cell phones, one gets the freedom to use a particular mobile phone on any network. To get a clear idea of what an unlocked cell phone is, one first needs to understand what a locked cell phone is.

A locked cell phone is a phone that is tied or ‘locked’ to a specific service provider and can only be used on the network provided by them. On the other hand, an unlocked cell phone is a phone that is not tied or ‘locked’ to any service provider and can be used with different service providers worldwide. Locked mobile phones only work with the Subscriber Identification Module (SIM) card supplied by the service provider to which the cell phone is locked. One can use different SIM cards in the locked phone, as long as they belong to the service provider that has provided the cell phone. If the cell phone is later unlocked, then it can recognize, and work with, any SIM card, irrespective of the service provider.

An example would help you better understand: ‘AT&T’ and ‘Sprint’ are two major service providers. A cell phone ‘locked’ to ‘AT&T’ or who’s SIM card is provided by ‘AT&T’, will only work with ‘AT&T’ SIM cards. SIM cards by other providers such as ‘Sprint’ , ‘Verizon’, etc, will not work on the phone. But if the phone provided by ‘AT&T’ is unlocked, it can be used it with other SIM cards provided by ‘Sprint’ or any other service provider. Similarly, cell phones provided by ‘Sprint’ can’t be used with ‘AT&T’ SIM cards or any other service provider for that matter, until they are unlocked.

Service providers usually enter into a contract with cell phone manufacturers, and get a particular system incorporated in cell phones, which disables the use of other networks on their handsets. In the US, the Apple iPhone works only on the AT&T network. One cannot use the iPhone with other service providers such as Sprint or Verizon. But once unlocked, it can be used with SIM cards that belong to any service provider.

If one needs a feature-rich mobile phone that is tied up in a contract with a service provider, and is not available with other networks, he may need to purchase it with a plan, and later unlock it. This is considered an option for people who need the same locked cell phone, but with a different service provider. However, as most providers have a 2 year contract, with early termination clauses, this can be a very expensive option. Mobile phones that work on the CDMA networks cannot be unlocked. However, locked cell phones working on the GSM networks can be unlocked. There are also disadvantages of using unlocked cell phones. If the service provider offers some exclusive facilities such as 3G and GPS on their high-end cell phones, these features would not work on an unlocked the cell phone, or with another service provider. In some cases, service providers help unlock the phone if the contract period is successfully completed, or if traveling out of the country.

Unlocking a mobile phone privately, without informing the respective service provider, may be illegal in some countries. However, mobile phone manufacturers may also offer unlocked cell phone for sale on their website or company outlet. If they do, you surely have a good chance to buy the phone you’ve been thinking of unlocking.

By Stephen Rampur

What are Unlocked Cell Phones?

For example, a locked T-Mobile phone cannot be used with a AT&T SIM card. If an unlocked cell phone is used, however, any SIM card can be used with it without having problems. 

Motorola V197 Unlocked Phone with Quad-Band GSM and Bluetooth

This unlocked cell phone can be used with a GSM network service provider and it provides quad-band connectivity (850 MHz, 900 MHz, 1800 MHz, 1900 MHz). It does not come with a SIM card, and it requires that you provide a SIM card.

Tips to Buying an Unlocked Cell Phone

The GSM is the type of phone used almost everywhere in the world, but the CDMA is a bit more common in the United States. While it is possible to unlock a cell phone, many people prefer to buy unlocked cell phones. 

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