Etiquette

Mobile phone etiquette has become an important issue with mobiles ringing at funerals, weddings, cinemas, and plays. Users often speak at increased volume which has led to places like book shops, libraries, movie theatres, doctors' offices, and houses of worship posting signs prohibiting the use of mobile phones, and in some places installing signal-jamming equipment to prevent usage (although in many countries, e.g., the United States, such equipment is currently illegal). Some new buildings such as auditoriums have installed wire mesh in the walls which prevents any signal getting through, but does not contravene the jamming laws.

Transportation providers, particularly those involving long-distance services, often offer a "quiet car" where phone use is prohibited, much like the designated non-smoking cars in the past. However many users tend to ignore this as it is rarely enforced, especially if the other cars are crowded and they have no choice but to go in the "quiet car". Mobile phone use on aircraft is also prohibited, because of concerns of possible interference with aircraft radio communications, although the airline Emirates have announced plans to allow limited mobile phone usage on some flights. In a similar vein signs are put up in UK petrol stations prohibiting the use of mobile phones due to safety issues. Most schools in the United States have prohibited mobile phones in the classroom due to the high amount of class disruptions that result from their use, and due to the possibility of photographing someone (without consent).

Subscriptions

In the UK, the number of cell numbers has surpassed the number of people. There will be over four hundred million cell phone users in China by 2008. Luxembourg has the highest mobile phone penetration rate in the world, at 164% in December 2005. In Hong Kong the penetration rate reached 117% of population in September 2004. The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005. Around 80% of world's population have mobile phone coverage as of 2006. This figure is expected to increase to 90% by the year 2010.

At present, Africa has the largest growth rate of cellular subscribers in the world. African markets are expanding nearly twice as fast as Asian markets. The availability of Prepaid or pay as you go services, where the subscriber does not have to commit to a long term contract, has helped fuel this growth on a monumental scale, not only in Africa but on other continents as well.

On a numerical basis, India is the biggest growth market adding about 6 million cell phones every month. With 156.31 million cell phones, teledensity in the country is still low at 17.45% and country expects to reach 500 million subscribers by end of 2010.

All European nations and most Asian and African nations have adopted GSM. In other countries, such as the United States, Australia,India, Japan, and South Korea, legislation does not require any particular standard, and GSM coexists with other standards, such as CDMA and iDEN.

Some cellular systems are pay as you go, where top-ups can be purchased and added to a phone unit, so there is no monthly bill. Many are "pay monthly", where a bill is issued every month for the amount of calls and text messages made.