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General GSM Information

What is GSM?

GSM (Global System for Mobile Communications) is the world's predominant mobile phone standard, first adopted in Europe and then quickly spreading throughout Asia, Africa and the Pacific Rim ( Australia , N. Zealand , etc.). GSM enables the same cell phone to work in London , Johannesburg , Beijing , Sydney and elsewhere.

The United States however, did not standardize GSM as a part of it's infrastructure, instead leaving the development of cellular service to competing wire carriers which created whatever standard they wished including CDMA and TDMA. Only recently has the US aggressively embraced the GSM standard.

What is a SIM card?

The SIM (Subscriber Identity Module) card also known as a "smart chip" is basically the "brain" of the phone, providing cellular service as well as many other functions including call log, voice mail and SMS and GPRS (internet connection standards). SIM cards are the size of a credit card but they have a pop-out chip about the size of a postage stamp which fits into all modern GSM phones. The smart chip is embedded with circuitry and when inserted into a GSM mobile phone provides wireless phone service on a particular GSM network. SIM cards are usually available prepaid or on a contractual basis.

Is this (SIM card) like a calling card?

Not really. You cannot receive a call with a calling card. Calling cards are a bit risky and often provide poor customer service. With the increasing popularity of mobile phones, it is not uncommon to find broken pay phones that go unrepaired by companies that own them.

I currently have a GSM Phone. Will it work overseas?

It is possible, though unlikely, that your current US GSM cell phone will work overseas. Most GSM phones sold in the US are only compatible with the nation-wide operating frequency of 1900 MHz (or the emerging 850MHz band). Overseas services use 900 and/or 1800 MHz frequency standards, which is why we carry only (unlocked) tri-band phones. Most carriers offer global tri-band phones, however they provide them "locked" which is a distinct disadvantage for the consumer.

What is a locked cell phone?

A locked cell phone is one that has been altered in order to use only one particular cellular network. This is often referred to as a service provider lock or "SP lock" for short. All GSM network operators lock the GSM cell phones they sell or offer with their cellular services. This is the hidden cost of the otherwise "free" or heavily-discounted phone you might receive directly from a network operator by signing a service contract. The cost of providing you with a "free" or low cost phone is subsidized over time through more expensive phone rates when you make calls domestically or roaming overseas. In the end, you end up paying much more for your "free" phone and service than you would if you purchased a package. An unlocked phone is therefore one where this software restriction has been removed.

What are PIN and PUK numbers?

Some prepaid SIM cards have a security mechanism in place that requires the subscriber to enter in a PIN (personal identification number) code every time the GSM cell phone is turned on. When a PIN code has been assigned it is important not to forget this code. If you enter the PIN code incorrectly into the phone 3 times in a row then your GSM cell phone will display a Blocked message on its LCD. When this occurs you will then be required to unblock your phone using the PUK code. If you enter the PUK phone incorrectly 10 times in a row you will block your SIM card indefinitely. All phones have a different set of procedures to unblock and you will need to consult your GSM cell phone manual when this occurs. We bly suggest that if you have the PIN-check feature enabled on your SIM card, that you turn it off. Please consult your phone manual's index under the "security" or "lock" section if unsure how to disable PIN-check.

Is it better to buy or rent the phones?

There is no simple answer for this. If your rental period approaches 2 months, you would be better off buying the phone. Also, if you travel often, it makes sense not having to keep paying for shipping. Renting a phone is a good way to try out our phone and see if you like it. If you decide to keep the rental, you pay no rental fee. You simply forfeit the deposit on the phone. On the other hand, purchasing a phone ensures you will be acquiring an unused handset.

How can I be sure the technology won't become obsolete in the future?

This certainly won't occur in the near future. In fact, this is a relatively new technology in the US that many of the cellular service providers are quickly embracing. Sure, there will always be newer, smaller and "better" cell phones introduced in the future, but the underlying technology powering the service will remain the same. Consider classic cars as an analogy; while they may be less modern, they still get you around because even the oldest vehicles use gasoline for power.