Health Risk Of Cell Phones

The cellular phone is a pervasive technology that has evolved from a luxury item justified only by the rich businessman to a necessity to some and an addiction to others. According to Portio Research Limited approximately 4.344 billion cell phones are in use globally. Since the latter part of 2008 one fifth of households in the United States have chosen this technology as their sole method of voice communication, replacing traditional landline telephones. Source: Fram, (2009). A 2009 Marist Poll found that “87% of U.S. residents say they own a cell phone.” So what exactly is a cellular telephone? History tells us that Alexander Graham Bell received the first U.S. patent for a communication device called the telephone in 1875. This device allowed a human voice to be transmitted across a cooper wire. We grew up with the telephone and in my generation every house had at least one telephone. The first patent for “cordless phone” technology was given in 1959 but the technology did not become commercially viable until the breakup of the Ma Bell monopoly in the early 1980’s, it was then that several companies started manufacturing wireless phone systems. These cordless phone systems were still connected to landlines but in actuality were two way radios using RF or Radio Frequency technology. Radio waves are part of the electromagnetic spectrum of radiation. Today’s cell phones use EHF (Extremely High Frequency) or microwaves which are the same technology our microwave ovens are based on. Because the telephone started out as a safe technology we grew up using, people do not even think about the possible negative health consequences of using their cell phone.
Cell phone usage has negative effects to your health. However when it comes to the health risks associated with using a cell phone, there is conflicting research.
Mobile phone technology is new and its effects are unknown.
We have only been using wireless communication technology for the last thirty years. There are not large enough studies conducted over long enough periods of time to come to the conclusion that this technology is safe. Cigarette smoking and even X-Rays where once thought to be safe, until enough information came to light to prove the dangers of using them. Most of the major studies have been done in countries that have a financial stake in the manufacturing of cell phones. Interphone is one of the largest studies ever done. It took place over the course of ten years and included the research of 13 different countries, comprising subjects from the age of 30-59. Even with large studies such as Interphone (which included 14,078 cases), there are on going debates about what the data actually means, thus with no conclusive results the report remains unpublished. “But one thing they all agree on is that more research is needed.” (Reardon, 2009, para. 6). Another issue involved is that the technology being used is rapidly evolving; the current incarnation of the cell phone is less than ten years old. The Stewart Report from the International Experts Group on Mobile Phones claims (Stewart, 2000, 40) “New Telecommunications technologies have been introduced without full provision of information about their nature and without prior discussion within the scientific community about the consequences for health.” The research is static while the technology is dynamic.

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The use of Cell phones increases the risk of cancer.
Using a cell phone held up against your ear can increase your risk of getting cancer or brain tumors due to the proximity of the radiations’ source to the head and brain. There are many studies available which indicate a link between various types of cancer and cell phone usage. A study done in Sweden by Dr. Lennart Hardwell showed that the risk of acoustic neuroma and glioma are increased from 20% (low grade giloma) to 400% (high grade giloma) by long term mobile phone use (>10 years), highest risk category being ipsilateral exposure. Source: (Harwell, Carlberg, Söderqvist, Mild & Morgan, 2007). Dr. Ronald B. Herberman, MD and Director of the University of Pittsburg Cancer Institute and UPMC Cancer Center testified before the Domestic Policy Subcommittee Oversight and Government Reform Committee “My attention was directed to a large body of evidence, including expert analyses showing absorption of RF into the brain and the comprehensive Bioinitiative Report, review of experimental and public health studies pointing to potential adverse biologic effects of RF signals, including brain tumors, associated with long-term and frequent use of cell phones held to the ear.” Source: Herberman, R. (2008). Dr Herberman felt strongly enough about the connection between increased cancer risk and using a cell phone that he issued a warning to his staff which included 10 detailed steps to reduce exposure to the RF electromagnetic radiation.
Cell phones do not cause cancer.
Sources such as the US Food and Drug Administration and the American Cancer Society have found cell phone usage has not been directly linked to an increased risk of brain, and other cancers. The United States Food and Drug Administration is the government agency responsible for evaluating and regulating the safety of products that emit radiation. These products cover medical to entertainment electronics. The FDA website under the topic of Radiation emitting products, health issues, a simple question is asked and answered, “Do cell phones pose a health hazard?” Source: www.fda.gov (2010). The answer clearly states the scientific evidence has not proven that cell phones cause cancer or any other health issues. The American Cancer Society has evaluated close to 30 studies which were focused on the relationship between tumors and cell phone usage. The results of these studies have been similar. “Most studies do not show a “dose-response relationship” — a tendency for the risk of brain tumors to increase with increasing cell phone use, which would be expected if cell phone use caused brain tumors.” Source: www.cancer.org (2010). Certainly these organizations are credible and have no financial interest in the outcome of this controversial health topic.
Mobile phones emit low-level RF.
Because the RF levels emitting are so low, there is no direct link between mobile phones and health issues. According to the FDA cell phone levels of RF are low putting them into the range of microwaves. Microwaves produce non-ionizing radiation, not to be confused with ionizing radiation such as gamma or x-rays which does have a damaging effect on biological tissue. The Federal Communications Commission defines a biological effect as a measurable change in a biological system. The presence of a biological change does not translate into something that is biologically harmful. When the biological effect “causes detectable impairment of the health of the individual or of his or her offspring” it is categorized as harmful to ones safety. Source: U.S. Federal Communications Commission, Office of Engineering and Technology, (1999). These RF levels are only at their peak when actually transmitting and receiving, which limits the amount of exposure.
The FDA stated that no prove existed that cellular phones are dangerous, however if people still have apprehension there many preventive methods that can be implanted to further decrease exposure to the already low level of RF energy.
Cartoon Interpretation
In this cartoon the author is suggesting that user is aware that using his cell phone is dangerous, by the comical way he attempts to protect himself with the metal helmet. In addition he appears to be discussing these concerns with his physician, who states “If you’re worried about the dangers of mobile phones why don’t you use it less.” As with any other type of radiation, the time of the exposure is one of the factors that determine the patient dose. By suggesting that the patient use his phone less the doctor is re-enforcing this principal. With the advent on new technologies such as mobile internet, text messaging and email people are using their cell phones for extended periods of time and carry them constantly. By turning the phone off when not in use the patient could further decrease his exposure. Another concept radiation protection uses is increasing the distance between them and the source of radiation. This patient could eliminate the need for his humorous helmet by using some ear buds with a microphone. The ear buds would allow him to use his cell phone without having the phone pressed against the temporal bone, which is in close proximity to the brain. Most cell phones today included these ear buds in the box, I know my Blackberry did. The other option is to use the speakerphone which is my personal favorite, especially in the car. I would also recommend he not carry the phone on his person, he could simply turn the phone off or put it in “Airplane” mode when not using it.
Conclusion
Radiation protection is founded on the premise that there is no safe amount of ionizing radiation. We should apply this approach when thinking about how and when we use our cellular phones even though they emit non-ionizing radiation. All the negative health implications of long-term cell phone usage are still unknown. Brain tumors take at least 10 to 20 years to manifest themselves. Source: Khurana, G. (2008). Taking a lesson taught to us from history with the health issues associated with x-rays and cigarettes, we need to take a more conservative approach when using a cell phone. Cell phones are now rated for how much specific absorbed rate per kilogram (SAR) they emit. There are many sources on the internet that compare the specific absorbed rate of phones from various manufacturers. Choose a cell phone model which emits a low amount of radiation to begin with. As consumers we should demand that objective studies be done over a long period of time using a number of subjects significantly relative to the amount of people using this technology. These studies must be conducted by experts in the medical community familiar with studying the mechanism of the causes of cancer. We should pressure our lawmakers to put in place more stringent requirements when it comes to minimizing the specific absorbed rate and improve the design to minimize. While not within the scope of this paper, I would be negligent not to mention the importance of controlling the cell phone usage of our children; their bodies are far more susceptible to the effects of RF radiation. Source: Khurana, G. (2008). The biggest challenge is to make people understand that no one is asking them to stop using their cell phone. Cell phones are an invaluable communication technology. For your own well being and that of your family please be aware of the dangers and how to limit the effects of them.
 

Health Dangers of Cell Phones and Ethical Selling

Table of Contents
Research Question
Introduction
Hypothesis
Definition of Electromagnetic radiation
Definition of Concept
Advantages of Mobile Phones
Disadvantages of Mobile Phones
Conclusion
Glossary
Bibliography
Acknowledgements
No table of figures entries found.
Research Question
In conjunction with the various health issues associated with society and its use of mobile phones, is it ethical for retailers to sell this device without informing the consumer about the dangers?
Introduction
One of the most influential innovations of the 20th century is undoubtedly the science of technology; people have become dependent on Information Communication Technology to the point that our ability and progress is stagnant without it. The demand put on the population to have sufficient knowledge of ICT is so high that one cannot hold a profession or even be successful throughout their education.
Now the most prevalent form of technology that influences our lives immensely is the mobile phone. Unfortunately the Information Communication Technology Industry is becoming widely known for perpetuating this product without informing the receivers about the adverse effects associated with its use.
Mobile phones are purchased everyday from common day to day destinations and with the excessive purchasing of this product, misinformation can therefore come across as negatively influencing the moral barrier between the consumer and seller.
(RUTKAUSKIENE, Danguole et al., 2011)
(FUNWORKS, 2013)
Hypothesis
The effect that mobile devices have on the users health is measured to a miniscule magnitude. In that result, it is unnecessary for the mobile technology industry to make provision for cautioning users about these effects and therefore dispelling it of a moral issue.
Definition of Electromagnetic radiation
Electromagnetic radiation are harmful and harmless waves consisting electrically charged particles, their harmful nature is all dependant on the lengths of the wave’s wavelength, the shorter the wavelength the more harmful the radiation is towards materials.
(ANNE MARIE HELMENSTINE, Ph.D.)
Definition of Concept
Due to mobile technologies prevalence in human life, discoveries have been found that associate the device with the ability to cause harmful electromagnetic radiation. The transmission of radiation is somewhat miniscule but the real issue is derived from people’s excessive use of the device.
Mobile phone’s transmit radio waves via base stations which in turn create radiofrequency waves that are electromagnetic. These waves cannot restructure chemical bonds within the human anatomy. Whether you are calling or just texting, when the mobile phone is on you are being exposed to radiofrequencies. Now if you are less than twenty centimetres away from your phone you are unfortunately in the vicinity of being exposed to radiation.
Accounting to the morality of this issue, not being informed that you are in fact being harmed can raise some concern but the reality is that the scale at which you are being harmed can be considered insignificant.
(BORRELI, Lizette, 2013)
(MANN, Marion, 2013)
Advantages of Mobile Phones
Mobile phones have the ability to provide us with opportunities and most of all ease of access to technology. Ease of access refers to people’s ability to reach data very quickly which might take hours to find through books and articles; the other reference is our ability to reach one another within minutes just by using the mobile phone’s technology such as calling, blogging, texting and even video calling.
The next aspect of mobile technology that makes it such an imperative part of our lives its user experience. The fact that no training or courses are necessary for someone to be able to use a mobile phone makes it very convenient as opposed to desktops which are very complicated. The various single task programs, called ‘apps’, diversify our personal abilities. People can now do things with their phones that they never expected would be possible.

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Mobile phone’s also provide a user the ability to be always connected. People love communicating and sharing data with one another, now the mobile phone doesn’t only provide us that possibility but also enables us to do it from where ever we are located. This skill has attracted several populations towards the product and away from any other previous forms of communication.
Mobile technology is technically amazing but it is just as great in social implications. Mobiles can mine data for its user at very high velocities as opposed to their counterparts, books and articles. Due to the speed at which information is received, now people can be sure not to be misinformed about global affairs and other natural activities. Ultimately research is now vastly simpler to search for and therefore the increase in productivity for businesses, schools, and other industries can be promised.
(STUDY OPPORTUNITIES – INFORMATION TECHNOLOGY, 2014)
Disadvantages of Mobile Phones
Electromagnetic radiation is one of the biggest challenges that face our population, now with the introduction of radiation in mobile phones, it only makes it a much bigger problem. Brain tumours, genetic damage, short term blood cells, nausea, vomiting and cancer; these are just a few of the effects that people are allowing themselves to be exposed to whenever they are exposed to a significant amount of radiation.
Mobile phones are not completely safe and that is the reality but one’s safety can be easily rectified by firstly keeping the phone about 20cm away from your body. This distance can also be achieved with the use of headsets which allow a connection with the phone by a few meters. Another prevention strategy is to keep your phone away from your waist due to the radiation exposed to the hip bones which are responsible for 80% of the blood cells formed in the human anatomy.
Ultimately the best prevention strategy for radiation exposure from mobile phones is by using it less. The more you use the mobile phone; the more exposure you get to radiation and the more likely you are to inherit cancer or genetic damage. This is not true because the comparison of ultraviolet radiation and radio wave radiation is to Hz and Hz respectively. Radio wave radiation, which is the radiation propagated by mobile phones, is classified as non-ionizing radiation; this type of radiation is known to have a maximum effect of heating on skin but mobile phones don’t even transmit enough radiation to have such an effect. Ultraviolet, however, is ionizing radiation and this type of radiation is needed in order to have even the slightest possibility of cancerous symptoms on human beings.
(U.S. FOOD AND DRUG ADMINISTRATION, 2009)
(VOLKOW ND, Tomasi D, Wang GJ, 2011)
(MATTSON, Dr. Barbara, 2014)
(KOVACH, Sue, 2007)
(RADIATION ANSWERS, 2007)
(MATTSON, Dr. Barbara, 2004)
Conclusion
The prevention strategies in conjunction with the various advantages that mobile technology imposes in society far outweighs the danger of radiation that mobile phone have on its user or society. The extent at which mobile phone’s emit harmful radiation is also very insignificant compared to the quantities required to have cancerous effects on the human population.
Thus, it is highly unnecessary for the mobile technology industry or retailers to make provision for warning the various mobile phone users and ultimately eliminating the possibility for a moral issue being raised with not informing users about its radioactive dangers.
Glossary
Bibliography
ANNE MARIE HELMENSTINE, Ph.D. Electromagnetic Radiation Definition. [online]. [Accessed 03 Auguat 2014]. Available from World Wide Web: http://chemistry.about.com/od/chemistryglossary/g/Electromagnetic-Radiation-Definition.htm>
BORRELI, Lizette. 2013. 5 Reasons Why Cellphones Are Bad For Your Health. [online]. [Accessed 03 August 2014]. Available from World Wide Web: http://www.medicaldaily.com/5-reasons-why-cellphones-are-bad-your-health-247624>
FUNWORKS. 2013. Module 2.2 E-Communications. [online].
KOVACH, Sue. 2007. The Hidden Dangers of Cell Phone Radiation. [online]. [Accessed 03 August 2014]. Available from World Wide Web: http://www.lef.org/magazine/mag2007/aug2007_report_cellphone_radiation_02.htm>
MANN, Marion. 2013. Optical Properties. In: Mind Action Series Physical Sciences Textbook and Workbook 12, Sanlamhof: ALLCOPY Publishers, pp.105-107.
MATTSON, Dr. Barbara. 2004. Imagine the Universe! Dictionary. [online]. [Accessed 04 August 2014]. Available from World Wide Web: http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html>
MATTSON, Dr. Barbara. 2014. Electromagnetic Spectrum – Introduction. [online]. [Accessed 04 August 2014]. Available from World Wide Web: http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html>
RADIATION ANSWERS. 2007. Effects of Radiation. [online]. [Accessed 03 August 2014]. Available from World Wide Web: http://www.radiationanswers.org/radiation-and-me/effects-of-radiation.html>
RUTKAUSKIENE, Danguole, Daina GUDONIENE, Caroline MICHALAK et al. 2011. ICT and Mobile Technologies in Practise. European Commission.
STUDY OPPORTUNITIES – INFORMATION TECHNOLOGY. 2014. Module 3.1 ICT and Society. [online].
U.S. FOOD AND DRUG ADMINISTRATION. 2009. Radiation-Emitting Products: Reducing Exposure: Hands-free Kits and Other Accessories. Silver Spring, MD.
VOLKOW ND, Tomasi D, Wang GJ. 2011. Effects of cell phone radiofrequency signal exposure on brain glucose metabolism. In: Cell Phones and Radiiofrequency, PubMed Abstract, pp.808-813.
Acknowledgements
Acknowledgements are sent to my senior phase Physical Science teachers, Mrs Carol Grout and Mrs Ilze de Beer, for the various knowledge accumulated from Optical Properties lessons. Credit also goes to my Information Technology teacher, Mrs Stapelberg, for the eCommunication and various other Information Communication Technology lessons that provided me with the competence to create this research task.
 
 

Comparison of Land Line & Mobile Phones

No one can ever forget Alexander Graham Bell, who is credited as the inventor of “Telephone”. With innovation and advancement in technology, the simple two way communicating device has taken a new form popularly known as “mobile phone”. We have reached an era where it is very common to hear words like “I can’t live without mobile phone”. Cell phone has become a part of our daily life. Let it be business deals, any personal work or meetings everything today can be done with the help of mobile phone.

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A Mobile Phone, Cell Phone or Hand Phone is an electronic device which lets the user to be mobile and make or receive telephone calls across a wide geographical area, served by many public cells. The calls could be made to and received from either a fixed line or another mobile. Mobile phone uses a wireless network for communication i.e. a network which is which is not connected by cables of any kind.
Base Station (BS).Each base station is in turn is connected to a central hub and is controlled by this switching office, also known as Mobile Switching Center (MSC). MSC is nothing else but a computerized center that is responsible for connecting calls, recording call information and billing. The communication between all the base stations and the telephone central office is coordinated by MSC. PSTN connects all conventional telephone switching centers with MSCs throughout the world.
Also, the cell size is not fixed and can be increased or decreased depending on the population of the area. Generally, the radius is kept 1 to 12 mi. In comparison to low density areas, high density areas require more geographically smaller cells to meet the traffic demands. Once the cell is determined, the cell size is optimized so that the adjacent cells signals are not interfered. For this purpose, the transmission power of each cell is kept low to prevent its signal from interfering with those of other cells.
Block Diagram of cellular Network
Difference between Fixed Line and Mobile Phone
In case of public switched telephone network (PSTN), the landline trunked lines (trunks) are used for transfer of information. These trunks comprise of fiber optic cables, copper cables, microwave links and satellite links. The network configuration in the PSTN is virtually static as the changes in the network connections would be required only when the subscriber would change the residence. Wireless networks, on the other hand are highly dynamic, wherein the network configuration is to be rearranged every time the subscriber moves into the coverage region of new base station. Unlike fixed networks which are difficult to change, wireless networks must reconfigure themselves for users within small intervals of time (on the fraction of seconds) to provide roaming and imperceptible handoffs between calls as a mobiles moves about. The available channel bandwidth for fixed networks can be increased by installing high capacity cables whereas wireless networks are constrained by RF cellular bandwidth provided for each user.
Frequency Reuse Principle
Increasing the capacity and coverage area is the key feature of any cellular network and this can be accomplished by re-using the frequency. It is true that to avoid interference, neighboring cells should not use same frequency but as the frequencies available is limited, they can be reused. A frequency reuse pattern is nothing else but a collection of N cells arranged together where N is the reuse factor, in which each cell uses a unique set of frequencies. The frequencies can be reused whenever the pattern is repeated.
F1,F2, F3,and F4 in the above diagram define the pattern with the reuse factor of 4.The cells that use the same frequencies(ones with the same frequency number) are known as reusing cells.
Transmitting and Receiving Calls
Whenever user makes a call from cell phone, the mobile station searches for a band with a strong signal to setup a channel and send the data to the closest base station using that channel. The base station then connects to Mobile Switching Center (MSC) and passes the data to it. MSC further passes the data to the telephone central office. A connection is established and result is sent back to MSC, if the called party is available. At this point MSC assigns an unused voice channel to the call and mobile station automatically adjusts its tuning to the new channel so that communication can take place.
Whenever a call is made to a mobile phone , the central office of the telephone from where the call has been initiated sends the number to the MSC.MSC in turn sends the query signals to each cell in process to find out the location of mobile station. This process is called paging. Once the mobile station is found MSC sends the ringing signal to it and after the station answers, a voice channel is assigned to the call for the communication to begin.
Handoff
The process of transferring the connected or on going call from one channel to another in order to prevent the termination of call is known as Handoff or Handover. Whenever the mobile station moves from one cell to another and signal becomes weak, handover is required. MSC monitors the level of signal every few seconds and if it finds the strength of signal diminishing then it searches for a new cell wherein better communication can take place. There are two types of handoff:
Hard Handoff: In this case, a mobile station communicates only with one base station. When the mobile station moves from one cell to another, the connection with the target cell is established only when the connection from the source is broken. Thus, such handovers are also known as break-before-make.
Soft Handoff: In this case, a mobile station can communicate with two base stations so there is no need of breaking from the source cell to make a connection to a target cell. Instead, a mobile station may continue with a new connection while retaining the older one for a while. Thus, such handovers are known as make-before-break.
Access Technologies
Frequency Division Multiple Access (FDMA): FDMA is a technique in which the spectrum is divided into frequencies and is assigned to users. The channel is assigned to only one subscriber or user at a time i.e. A channel will remain blocked until the call which was initially made has completed. A “full duplex” FDMA requires two channels, one for sending or transmitting the data and another for receiving. FDMA technology was used in first generation systems, which were analog systems.
Time Division Multiple Access (TDMA): TDMA splits each frequency into time slots thus improving spectrum capacity. In TDMA technology, each user is allowed to access the entire radio frequency channel for the short period of a call. The same frequency channel can be shared by other users as well at different time slots. The base station continually switches from user to user on the channel. The second generation mobile cellular network is dominated by TDMA.
Code Division Multiple Access (CDMA): CDMA simply means communicating with different codes. It allows all the users to occupy all channels at the same time thus increasing the spectrum capacity. Each voice or data call is assigned a unique code, so that calls could be differentiated from each other while being carried over the same spectrum. In case of CDMA terminals can communicate with various base stations using the feature known as “soft hand-off”.
Mobile Generations: Evolution from 1G to 3G
With the rapid advances in technology and the greater selection of new wireless services and applications the mobile has grown through various generations fulfilling the increasing demands of its users. First Generation (1G) mobile phones were analog which had only voice facility. Additional facilities like messaging and data services, fax were introduced in digital phones known as Second Generation (2G) mobile phones. The third generation mobile phones (3G) which are being talked about a lot nowadays, includes high speed of internet browsing, picture and video messaging facilities. In short, multimedia facilities when added to the second generation mobiles (2G) gave birth to the third Generation mobile phones.
First Generation Mobile System: The cellular networks were introduced in 1980’s and since then it has not stopped growing. The first generation mobiles were analog systems with the capability of transmitting at the speed of 9.6 kbps max. At that time there was no worldwide coordination for the development of technical standards worldwide. AMPS (Advanced Mobile Phone System) was invented in Bell Labs and was installed in United States in 1982.When used in England and Japan it was known as TACS and MCS-L1.In 1G mobile systems roaming was not possible and efficient use of frequency spectrum was not there.
Second Generation Mobile System: ETSI was created in Europe in mid 1980s to standardize the mobile communication sector. This standardization lead to the beginning of new network which was based on digital technology and popularly known as Global System for Mobile Communication (GSM).GSM was actually introduced to add more services to the actual network as well as meet the requirements of data traffic. GSM consists of the following three main components:
1. Base Station Subsystem 2.Network Subsystem 3.Network Management System
Base Station Subsystem: It consists of Base Transreceiver Station (BTS), Base Station Controller (BSC) and Transcoder sub-multiplexer (TCSM).BTS is the network component that manages the interface between mobile station and the network. Mobile terminals are connected to the BTS through the air interface. BTS makes use of omnidirectional or directional antennas for transmission and reception. BSC provides major functions like handover and managing radio resources.
Network Subsystem: Network subsystem is basically an interface between the public network and GSM network. All the communication between mobile users and other users (ISDN, fixed, mobile) is managed by NSS. The databases of subscriber and is also kept with NSS to manage users mobility. Various components of NSS are described below:
1) Mobile Switching Center (MSC): It is the most important component that performs switching functions necessary for interconnections between mobile users and other users (fixed or mobile).
2) GMSC: To connect the cellular network with PSTN, a gateway known as GMSC is used.
3) Home Location Register (HLR): All the information about the subscriber such as the coverage area, services provided to the user, current location and mobile equipment status etc is maintained in this register. The database remains same until the termination of subscription.
4) Visitor Location Register (VLR): The information of subscriber is uploaded in this register whenever he enters the coverage region so that necessary services could be provided to him. VLR of the new region is updated with the database whenever the subscriber moves to the new region. VLR is dynamic in nature as it keeps the data of the subscriber temporarily and interacts with HLR for recording the data.
5) Authentication Center (AUC): It takes care of the security by providing standards for encryption and authentication of users. Encryption key is kept in mobile equipment as well as AUC to protect the network from unauthorized access.
6) Equipment Identity Register (EIR): All mobiles are identified using IMEI (International Mobile Equipment Identity) number which is written on the battery of the phone. EIR keeps the list of all valid IMEI number and whenever a call is initiated, the network checks the IMEI number and call is connected if the number is valid. No calls are allowed from unauthorized terminals.
7) GSM Interworking Unit (GIWU): GIWU is an element or a unit that is a combination of hardware and software and synchronizes the information. It lets the user to choose between message and speech mode by acting as an interface to different networks.
Network Management System: The third element of GSM basically monitors the different elements and functions of the network. It performs the following main tasks:

Network Monitoring
Network Development
Network Measurement
Fault Management

NMS continuously monitors the performance of the network to ensure it runs smoothly. The performance can be measured by collecting the data from the individual elements for analysis and storing it in the database. The network operator can then compare the data collected in the database with the one which was actually expected. If any fault occurs,
the fault alarm is generated .These faults are then required to be corrected either by NMS or manually.
Interfaces in GSM
Different interfaces are used in GSM. These are Air , Abis and A interface.Air interface is an interface between Mobile station and Base Transreceiver Station (BTS),Abis connects Base Transreceiver Station (BTS) to Base Station Controller (BSC), and A interface is the one which is present between TCSM and MSC.
GSM Architecture
Value added services such as voice mail and short message services (sms) were added to GSM along with intelligent services like Pre-paid and fraud management. Later on, GPRS (General Packet Radio Services) was introduced so that packet switched data service could be provided. SGSN (Serving GPRS) and GGSN (Gateway GPRS) were new elements which were introduced in the existing system so that packets could be sent to air interface. IP routers, firewall servers and Domain name servers were also used along with these elements. Finally, to increase the data rate better coding methods were used.
Third Generation Mobile System
http://it.med.miami.edu/x1645.xml