Health effects

There exists a community that believes mobile phone use represents a long-term health risk, although this is currently disputed by the World Health Organization, with forthcoming mobile phone usage recommendations in 2010 Certain countries, including France, have warned against the use of cell phones especially by minors due to health risk uncertainties. Groups of scientists, such as the U.S.-based group Bio initiative, argue that because mobile phone use is recently introduced technology, long-term "proof" has been impossible and that use should be restricted, or monitored closely, while the technology is still new.

The effect mobile phone radiation has on human health is the subject of recent interest and study, as a result of the enormous increase in mobile phone usage throughout the world (as of June 2009, there were more than 4.3 billion users worldwide Mobile phones use electromagnetically in the microwave range, which some believe may be harmful to human health. A large body of research exists, both epidemiological and experimental, in non-human animals and in humans, of which the majority shows no definite causative relationship between exposure to mobile phones and harmful biological effects in humans. This is often paraphrased simply as the balance of evidence showing no harm to humans from mobile phones, although a significant number of individual studies do suggest such a relationship, or are inconclusive. Other digital wireless systems, such as data communication networks, produce similar radiation.

The World Health Organization, based upon the majority view of scientific and medical communities, has stated that cancer is unlikely to be caused by cellular phones or their base stations and that reviews have found no convincing evidence for other health effects. The WHO expects to make recommendations about mobile phones in 2010^. Some national radiation advisory authorities have recommended measures to minimize exposure to their citizens as a precautionary approach.

At least some recent studies, however, have found an association between cell phone use and certain kinds of brain and salivary gland tumors. Lennart Hardell and other authors of a 2009 meta-analysis of 11 studies from peer-reviewed journals concluded that cell phone usage for at least ten years “approximately doubles the risk of being diagnosed with a brain tumor on the same ("ipsilateral") side of the head as that preferred for cell phone use.

Privacy

Governments, law enforcement and intelligence services use mobiles to perform surveillance in the UK and the U.S. They possess technology to activate the microphones in cell phones remotely in order to listen to conversations that take place near to the person who holds the phone^.

Mobile phones are also commonly used to collect location data. While the phone is turned on, the geographical location of a mobile phone can be determined easily (whether it is being used or not), using a technique known multilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phones.

In schools

Some schools limit or restrict the use of mobile phones. Schools set restrictions on the use of mobile phones because of the use of cell phones for cheating on tests, harassment and bullying, causing threats to the schools security, distractions to the students, and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities, public restrooms and swimming pools due to the built-in cameras that most phones now feature.

While driving

Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accident. Because of this, many jurisdictions prohibit the use of mobile phones while driving. Egypt, Israel, Japan, Portugal and Singapore ban both handheld and hands-free use of a mobile phone whilst many other countries—including the UK, France, and many U.S. states—ban handheld phone use only, allowing hands-free use.

Due to the increasing complexity of mobile phones, they are often more like mobile computers in their available uses. This has introduced additional difficulties for law enforcement officials in distinguishing one usage from another as drivers use their devices. This is more apparent in those countries which ban both handheld and hands-free usage, rather those who have banned handheld use only, as officials cannot easily tell which function of the mobile phone is being used simply by visually looking at the driver. This can lead to drivers being stopped for using their device illegally on a phone call when, in fact, they were using the device for a legal purpose such as the phone's incorporated controls for car stereo or satiny.

A recently published study has reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety

Mobile phones in society

The world's largest individual mobile operator by subscribers is China Mobile with over 500 million mobile phone subscribers.Over 50 mobile operators have over 10 million subscribers each, and over 150 mobile operators have at least one million subscribers by the end of 2009 (source wireless intelligence).

Competitive forces emerged in the Asia Pacific (excluding Japan) region at Q3 2010 to the detriment of market leader Nokia. Brands such as Micromax, Nexian, and i-Mobile chipped away at Nokia's market share plus Android powered smartphones also gained momentum across the region at the cost of Nokia.

Based on IDC India, Nokia's market share dropped significantly to 36 percent in the second quarter, from 56.8 percent in the same quarter last year and further drop to 31.5 percent in the third quarter, reflecting the growing share of Chinese and Indian vendors of low-end mobile phones.

Based on IDC in the last quarter of 2010, RIM has been knocked out from the top five list global mobile phone sellers. The number one rank is still Nokia followed by Samsung, LG Electronics, ZTE and Apple. For the first time Chinese ZTE is among the top five list and mainly make of lower cost phones.

Battery

Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Lithium ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-polymer batteries as opposed to the olderLithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternative power sources, includingsolar cells.

Charger efficiency

The majority of energy lost in a mobile phone charger is in its no load condition, when the mobile phone is not connected but the charger has been left plugged in and using power. To combat this, in November 2008, the top five mobile phone manufacturers Nokia, Samsung, LG, Sony Ericsson, and Motorola set up a star rating system to rate the efficiency of their chargers in the no-load condition. Starting at zero stars for >0.5 W and going up to the top five star rating for <0.03 W (30 mW) no load power.

A number of semiconductor companies offering flyback controllers, such as Power Integrations and CamSemi, now claim that the five-star standard can be achieved with use of their product. 

EU common External Power Supply

In 2009, many mobile phone manufacturers signed a Memorandum of Understanding (MoU), agreeing to make most new data-enabled cell phones marketed in the EU compatible with a common External Power Supply (EPS). All signatories agreed to develop a common specification for the charger "to allow for full compatibility and safety of chargers and mobile phones." The mobile phone manufacturers who have agreed to this standard include the original signatories Apple, LG, Motorola, NEC, Nokia, Qualcomm, RIM, Samsung, Sony Ericsson, and Texas Instruments as well as Atmel, Emblaze Mobile, Huawei Technologies and TCT Mobile (Alcatel). The Memorandum of Understanding also provides for the use of the common External Power Supply with compliant phones not equipped with a MicroUSB receptacle: "...4.2.1...if a manufacturer makes available an Adaptor from the Micro-USB connector of a Common EPS [External Power Supply] to a specific non-Micro-USB socket in the Mobile Phone, it shall constitute compliance to this article."