Electro Magnetic Fields
As the main telecom operator in Taiwan, TWM has been concerned about the safety of electromagnetic waves for a long time. In order to take the correct concept of electromagnetic waves to the civil and to reduce the doubt about the electromagnetic waves of residents who live near the base stations, TWM cooperate with the Taiwan Telecommunications Industry Development Association to provide telecommunications services consulting and complaints, in addition to provide excellent communication quality, a safety and healthy communication environment is important as well.
The measures to communicate with the public about the electromagnetic wave
- Send base station electromagnetic wave propaganda to community and neighborhood every year
- SProvide 0800-580010 toll free service of electromagnetic measurement.
- STWM invited third party fair unit to do the measurement services, and there were total 248 cases serviced in past 3 years.
- STWM cooperate with the Telecommunications Industry Association to construct the "Base station electromagnetic wave measurement service website".
- SCoordinate with the NCC base station electromagnetic wave propaganda policy, carry out the measurements tours around Taiwan.
- Each year, five local media tours are held in collaboration with the Telecommunications Industry Association.
- Inquire electromagnetic wave service unit
- Free electromagnetic measurement service
- Base Station electromagnetic wave knowledge
Common sense of Electro Magnetic Fields
Taiwan mobile communication applies the cellular system. It divides serving area into several hexagonal grids based on coverage and capacity. Each hexagonal grid has a base station to transmit and receive mobile signal. As mobile phone call moves from one place to the next, it is handed-over by one cell to another without interrupting a call.
Mobile communication is a "two-way communication mode", when the user makes calls, the mobile phone will search the nearest base station for communication. The distance between the base station and the mobile phone will affect the transmission power of the mobile phone, when the phone is closer to the base station, the phone's transmit power is also lower.
Mobile communication has an "automatic gain control system", when the phone starts to talk, at this moment the power of mobile phone is the strongest, but after the success of the call, the transmission power will reduce to between 0.001 watts and the maximum power (less than 1 watt). Hence to increase the battery life and the talk time.
It was suggested that the base station should be moved to rural areas or sparsely populated. It were different from the one-way transmission of radio stations or television stations, the mobile communication is a "two-way communication mode". If base station is far from the crowd, which may cause poor communication quality. In order to avoid drop calls, the mobile phone will increase the transmit power.
The safety standard of electromagnetic wave of base station in Taiwan is approved by “International Commission on Non-Ionizing Radiation Protection (ICNIRP)”, which is the international independent scientific organization, and also approved by World Health Organization (WHO)”. For the safe of public health, ICNIRP take the health effect into consideration 50 times stricter then the theoretical value, when it drew up the safety standard of electromagnetic wave of base station. Now this standard is followed commonly in global. EU, New Zealand, Australia, Japan and Taiwan are all follow this standard to develop the electromagnetic wave regulatory standards of handset and base station.
The electromagnetic wave of the base station is a non-ionizing radiation with non-thermal effects. Not like nuclear waste and atomic energy that will produce harmful ionizing radiation to human body. The base station electromagnetic wave does not cause radiation damage. So, it’s very safe for the environment as well. Please rest assured.
According to the provisions of National Communications Committee Taiwan, the effective transmit power of the base station shall not exceed 500 watts. (Compare with about 1 million watts of FM radio power, the transmit power of the base station is negligible). Most base stations are far from the adjacent buildings over than 10 meters, the power of electromagnetic wave at least 1000 times lower, please rest assured.
The frequency of the Mobil base station is different from home appliances that we use. The Communication system uses ultra-high frequency band and home appliances frequency band is far apart. it will not cause interference problems. Please rest assured.
Watt (W) is the unit of power, meaning the energy consumed or diverge out per unit time, and can be used as electrical appliances energy consumption measurement units, or the measurement unit of the radiated energy of the electromagnetic wave. The relationship between these three are: 1 watt=103 milliwatt =106 microwatt.
The specific frequency of the base station is called microwave (MW) or radio frequency (RF) radio waves. Usually we measure the plane wave power density, generally written μW / cm2 (microwatt / Square centimeters). We hear constantly that "Gauss (Gauss)" is the measurement unit for the strength of the static magnetostatic field, not correct to use to measure the electromagnetic waves. When using the Guass Meter to measure the magnetic field strength of the electromagnetic wave, the frequency range of the measurement must be less than 500 kHz. But for GSM systems, the frequency of antenna transmission is 900MHz and 1800MHz, both are higher than 500 KHz. Hence it is not correct to measure the magnetostatic field strength of the radio wave with the Gauss meter; also the measured magnetostatic field may be generated by the other power equipment.
According to the “Mobile phone service base station technical verification specification” which is amended on Jan 21, 2000, the standard value of electromagnetic wave safety for base station in Taiwan as below:
- Standard value for safety of GSM 900 electromagnetic wave is less than or equal to “0.6 mW per square centimeter”
- Standard value for safety of GSM 1800 electromagnetic wave is less than or equal to “1.2 mW per square centimeter”
The standard value is the same with the standard of IEEE (Institute of Electrical and Electronics Engineers), and the base stations in Taiwan where rigorous field tested and approved by EPA (Environmental Protection Administration, Taiwan), and the output electromagnetic wave power of base stations were between 0.00000001 and 0.00001 mW per square centimeter which is much lower than standard value, which is absolute safety to people.
UK and Japan formulate similar standard value as Taiwan. Apparently, The regulatory control of the electromagnetic wave in Taiwan is the same prudent and rigorous as advanced countries.
Cellular system is integrated by placing the base stations on a grid. A base station covers a designated geographical area with limited transmission power. Radio channel can be reused by spacing base stations with a suitable distance.
Grid coverages are reduced to insert a new station into the cellular system, and transmission power is also saved both in base station and mobile phone. Therefore, electromagnetic power is lower in dense urban which grid size is smaller.
First at all, we shall clarify some concept about radiation. Radiation is divided into three finds.
|non-ionization radiation||Can destroy biological cellular molecule，such as gamma(γ) radiation、X-ray.|
|2. non-ionization radiation (with thermal effect)||Will not destroy biological cellular molecule，but produce temperature changes, visible light, infra-red ray.|
|3.non-ionization radiation (non-thermal effect)||Will not destroy biological cellular molecule and not produce temperature changes, such as radio waves, electromagnetic field|
X-rays are in very high frequency segments. The energy of the electromagnetic particles is sufficient to interrupt the chemical bond (ionization). So the X-ray is harmful to the human body.
But in relatively low frequency segments, such as radio waves, the energy of the electromagnetic wave particles is too low and does not interrupt the chemical bond. And so called the radio wave as non-ionization radiation. The biological effects of Non-ionization radiation (radio wave) and ionization radiation (X-ray) are not the same
Absolutely not. The Environment Protection Administration issued a press release on April 25, 2000 indicating that the electromagnetic waves emitted by the base station belong to non-ionizing radiation. After investigation by the commissioned academic research units, the power of the domestic base station electromagnetic waves was below international standards, and will not endanger people’s health. So the Environment Protection Administration did not classify the base station as source of pollution.