"Any time! Any where! Decades ago there was no such thing" - "Communication". Then, September 7th 1987, the global system for mobile communication or GSM was born. And international agreements that laid out the standards, regulations and practices gave rise to a global mobile phone industry. To be honest, the world's first mobiles were not so attractive and the range of effectiveness wasn't very good. But they became a must-have among those wealthy people who could afford that. However, by advantage of GSM which has many different elements to it, we can all enjoy the ability to go around the world in 217 countries, land in that country and know that a phone would work. There are other cell phone systems using different technology in the world. The majority of the United States and parts of South America have been using something called CDMA which is very rare in Europe. In some Asian countries like China, GSM and CDMA both exist at the same time. But the GSM Association claims 85% of the global mobile phone market. They estimated there are now about 2.5 billion different users who make more than 7 trillion minutes of calls everyday, and that's not all. 20 years later, the mobile phone is so much more than just a phone. You can use it to send text messages, take pictures, show video, even surf the internet. "The phone itself is involved from just being a communication tool, to be a tool for round-the-clock connectivity, you can not live without it even in a minute." Mobile consultant Nick Lane also points out with so many customized styles and features, your mobile phone will become a symbol of you. Where will the global mobile phone industry be in another 20 years? Certainly, there will be more connections than better coverage. As for where else technology will take us, one can only imagine. From this passage, we can infer that   _  .
as soon as the first mobiles appeared, they became popular and many people have one with a GSM mobile phone, you can make a phone call in most parts of the USA there are only two cell phone systems in the whole world: GSM and CDMA most of the mobile phone users in the world now are using the GSM mobile phone