Mobile phones have become very popular in recent years and their development has been amazing. It is no wonder why they have become irreplacible. With all applications which go with them they have gained a huge popularity with teenagers.
A mobile phone (also known as a cellular phone, cell phone and a hand phone) is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator. The calls are to and from the public telephone network which includes other mobiles and fixed-line phones across the world. By contrast, a cordless telephone is used only within the short range of a single, private base station. 
The quality of sleep of almost half of 16 year olds may be affected by text messaging on mobile phones, a study from Belgium says.
The sleep of one in four 13 year olds could be affected too, says the researchers, who looked at the effects of text messaging on sleep interruption in teenagers (Journal of Sleep Research (2003:12:263).
In the research, about 2500 first and fourth year children (aged 13 years and 16 years respectively) in the Leuven study on media and adolescent health (SOMAH) based in Flanders, Belgium, were asked how often they were awoken at night by incoming text messages on their mobile phone.
In the first year students, 13.4% reported being woken up one to three times a month, 5.8% were woken up once a week, 5.3% were woken up several times a week and 2.2% were woken up every night. In the fourth year group, 20.8% were woken up between one and three times a month, 10.8% were woken up at least once a week, 8.9% were woken up several times a week, and 2.9% were woken up every night. The teenagers were also asked to indicate how tired they felt at various times.
“These preliminary findings suggest that mobile telephones may be having a major impact on the quality of sleep of a growing number of adolescents. It affected a quarter of the youngest to almost half of the eldest children in the sample,” says Jan Van den Bulck of the Katholieke Universiteit Leuven, who reports the findings in a letter to the journal. 
Cell phones are a great invention and a popular way to communicate—half of all Americans and Europeans use one. They allow us to work on the go and stay in touch. When put in the hands of a teenager, however, they can have some effects of which adults should be aware.
Cell phones provide security for teens and parents who worry about them; help is never out of reach and parents can check on their children easily.
Young people’s ability to communicate is extended—they can reach more people (including family) on a daily basis with cell phone speech and texting.
Teens’ natural tendency to follow trends may result in an emotional attachment to a cell phone (in its latest model) that is out of scale with its actual value. Some teens may even develop an “addiction” to the device that excludes anything not viewed or heard.
Cell phones allow only verbal, disembodied relationships at a time when adolescents should be working on developing a sense of their own—and others’—physical space. 
The acquisition of a cell phone appears to influence the communication choices of teens. In particular, cell phone users are much less likely to choose to use email than teens without cell phones. When asked which medium teens used to send written messages to friends most often, teens with cell phones were much more likely to select instant messaging and text messaging than email, while teens without mobile phones were more likely to choose email or instant messaging as their most favored textual method of communicating with friends. And while all teens are more likely to say they most often talk on the phone when communicating with their friends, teens with cell phones are more likely than teens without to say that they most often communicate with friends by written messages rather than the phone. Sixty-seven percent of teens without cell phones say they use a phone most often when communicating with their friends, compared to 58% of teens with a cell phone. So even though they potentially have more opportunities to talk on the phone than teens without cell phones, cell phone owners prefer to communicate with friends via written communication. 
It is a common sight – cell phones (mobile phones) in the hands of people, especially teenagers. Literature has provided in-depth evidence of the uses, advantages, disadvantages, impact, consequences and concerns about the use of mobile phones. Why teenagers fancy this device, is an interesting observation where the experts attach its significance to teenagers’ identity factor. The usage of mobile phones has re-shaped, re-organised and altered several social facets. Particularly focussing on teenagers’ mobile phone usage, literature has provided evidence of them being used for both positive purposes and negative reasons. Teenagers possessing mobile phone/s were 96.5% (n=111). A further breakup of age groups indicated that all the 17-19 olds had mobile phones. In addition, not possessing mobile phone/s is higher in the age bracket 15-16 year olds when compared to 13-14 olds. 
The spread of mobile communication among Finnish teenagers has been markedly rapid during the latter half of the 1990s. Young people have created and developed a communication culture that incorporates many special features, such as a rise in the use of text-based communication channels. Teenagers’ intersecting and selective use of communication channels has generated multimedial communication. From the theoretical standpoint provided by symbolic interactionism, we can ask whether communication through new media technologies generates new forms of social interaction. If this is the case, how could we describe and analyse these new forms of interaction? The media landscapes created by teenagers serve to articulate their personal space, as well as enabling their presentation of self and defining their relationships to others.[ 6]
The influence of mobile technology on our lives is huge and even greater on teenagers. In the age in which they’re developing as individuals all that mobile phones birng leaves a strong trace on their growing up. The usage of mobile phones in their age should be controlled but they shouldn’t be discouraged from using them as they bring many benefits.
 ”Text messaging is spoiling teenagers’ sleep” by Roger Dobson
 ”The Effects of Cell Phones on Teenagers” by Laura Reynolds
 ”Teens and Technology” by Amanda Lenhart, Paul Hitlin, Mary Madden
 ”Mobile phones and teenagers: Impact, consequences and concerns – parents/caregivers perspectives” by Ravidchandran, Shanthi
 ”Mobile Communication as a Social Stage Meanings of Mobile Communication in Everyday Life among Teenagers in Finland” by Virpi Oksman