Then it will discuss some of the most important points to consider when selecting a team of cellular communication. Flexibility in coverage options the majority of equipment sold directly by cellular communication service providers are blocked so that they can only be used with that company, which limits the flexibility of the user to change the company in your country or if you travel abroad. It is possible to purchase unlocked devices with independent vendors which allows greater independence to the user when selecting a provider of cellular communication services. Altavista has much experience in this field. Another important point to consider is the type of communication technology that uses cell phone, the main types are: GSM (GROUPE SPECIAL MOBILE) CDMA (CODE DIVISION MULTIPLE ACCESS) TDMA (TIME DIVISION MULTIPLE ACCESS) UMTS (UNIVERSAL MOBILE TELECOMMUNICATIONS SYSTEM) IDEN (INTEGRATED DIGITAL ENHANCED NETWORK) by issues of mobility and flexibility, GSM is the dominant technology in the current telephony market and focusing her in this document, there are 4 frequencies worldwide, which are: 850 MHZ (CONTINENTE AMERICANO/ASIA) 900 MHZ (Europe ASIA) 1800 MHZ (Europe/AFRICA/ASIA) 1900 MHZ (Americas) depending on the amount of bands that a phone support is classified: Dualband (850/1900)Triband (850/1800/1900) or Quadband (850/900/1800/1900), the latter works in all countries with GSM network, therefore it is the characteristic suitable for someone that travels constantly, for example in case of a computer is unlocked it has the flexibility to reach any country with GSM coverage, buy a Chip, install it on your phone and make calls at local rateswhich is a great advantage. Aesthetic design: another aspect to consider is the importance of the aesthetic design team saves with regard to ease of use, with regard to styles of equipment, the following are the principal in the current market: BLOCK or BAR: Is the most robust, solid and simple style because they have no moving parts better supports falls and the rough use, they have the keys and screen at the front of the computer, the disadvantages which presents are few, are generally larger than other styles or have keyboards or smaller screens, the microphone is located furthest from the mouth when speakingIn addition to be susceptible to the keys are pressed by mistake into a pocket or handbag, and can make calls by mistake (many have received them), need to remember keypad lock or schedule it to do so automatically. .