Cellular communication network works by imaginary geographical division of the area we wish to cover (for example, USA). The division is made into cells and this gives us cellular network. Each geographical cell has base station. The station connects between users within the same cell and the national telephone network.
Do cell phones discharge radiation?
Yes, cell phones transmit, meaning, discharge electromagnetic radiation within frequencies of radio, called RF. This radiation is the same kind used by all wireless communications- radio and TV stations, wireless phones, mobile two-way radio and etc. wireless communication can not exist without RF. Today the broadcast is usually made inside 800-960 MHz frequency and in higher frequencies (1800-1900 MHz).
The cell phone radiation is usually transmitted from the antenna and to a lesser degree by other parts of the device. There is no difference between the broadcast signal power and the level of exposure whether it is incoming or outgoing calls.
Is the level of transition’s power constant?
No. the level of telephone transmission very much depends on how it received by the station and therefore, while moving the level changes. As the site receives the transmission stronger than it is required, it orders the cell phone to lower the power level of the transmission and vice versa. This process was originally meant to ensure optimal working conditions for the network and to extend the battery duration, but it also reduced the radiation exposure to the user. Therefore, the Specific Absorption Rate (SAR) works much lower than the level measured in the lab by turning on the cell phone into maximum output.
How can we know what the level of transmission in any given moment is or place?
There is no simple answer. However, the signal level is marked on the device’s screen and can give us rough estimate: the better the signal, so the broadcast level is lower.
What is the maximum exposure level (SAR) allowed from cell phones?
There are two standards in the world nowadays for exposure limit. They both limit the highest level of exposure at some point in our heads. There is also reference to exposure of all of the body and different body parts, which will not be discussed in here.
The American FCC standard from 1996 requires that the absorbed output in each head rissue, weight of 1 gram, will not exceed 1.6 mW, meaning SAR<= 1/6 W/Kg.
The International Radiation Protection Association (IRPA/ICNIRP) recommendations from 1998 demands the absorbed output in each head tissue, weight of 10 gram, will not exceed 20 mW, meaning SAR<= 2W/Kg.
The measurement of the cell phone radiation exposure is very expensive and complicated and the precision depends on the method and severity of the measurement.
How can I measure the SAR from my cell phone?
There is no practical option to conduct such measure since it requires complicated and expensive system. Such measurement is not necessary since significant differences are not expected from measurement of different phones from same type. Attaching different measuring devices into antenna (such as microwave) is not the right method to measure cell phone radiation .
To conclude: all we can say is that the maximum SAR is the best tool we have to value the cell phone radiation levels and therefore we use it to define the allowed level of exposure.
