Hallo,
eine interessante Kalkulation aus dem Abschlussbericht des Projekt "miniWatt II" (20 MB) http://www.ihe.uni-karlsruhe.de/download/miniWatt_II_web_version.pdf (pdf-Seite 149 ff)
ist die Bestimmung der durchschnittlichen Mobilfunk-Immission über Deutschlands Fläche (360 000 km²), Stand 2005.

Mobilfunk-Basisstationen: 7.3 μW/m²
Mobilfunk-Telefone: 0.02 μW/m²

Anmerkung:
Bezieht man sich nur auf die besiedelte Fläche (12,7%), so erhält man:
Mobilfunk-Basisstationen: 57,5 μW/m²
Mobilfunk-Telefone: 0,16 μW/m²

Average exposure
In contrast to the preceding section, the here investigated comparison between the exposure due to BTS and mobile phone will not be performed on a location based manner, but on a more global manner by comparing the averaged exposures. It has to be taken into account, that this averaged investigation is NOT relevant for any kind of comparison with the public exposure limits. Due to time and location averaging, it is more suited for comparing the global exposure budgets.
The determination of the averaged exposure is performed by integrating the transmitted power of BTS and mobile phones, respectively, taking into account specific parameters like power control, DTX, operation times etc. For the sake of simplicity the overall exposure of a BTS is regarded as its total transmitted power, neglecting the small part which is radiated into the atmosphere.
By dividing the calculated averaged power by the overall area of Germany, it is possible to extract an area averaged exposure in the dimension of a power flux density. The area of Germany (approximately 360,000 km2) is taken as a common reference value for both BTS as well as mobile phone integrated power, regardless of possible distribution differences between both exposure sources. An introduction of different "typical" exposure areas (e.g. with a radius of 300 m around a BTS and 5 m around a mobile phone) would result in a more "individual exposure" investigation, which was discussed in the preceding section. For a global view, the reference area has to be the same for BTS as well a mobile phones.

Average exposure from Base Stations
Due to information given by the network operators, at the end of 2005 about 84,700 mobile phone base stations (GSM+UMTS) were in operation in Germany. Each BTS is assumed to consist of three sector antennas.
For the control channels (BCCH for GSM, Pilot Channels for UMTS) an average power of 8 W for each sector is assumed (10 W for GSM, around 3 W for UMTS). In addition to the control channels one or more traffic channels can be active, dependent on the actual traffic load of the station. Insofar, the time dependent emission of the BTS depends on the number of users, the quality of the phone connection (power control) as well as of the listen/talk state (DTX).
Investigations in [Leh 04] have found an average transmit power of 43 % of the maximal station power for a typical GSM 3 channel BTS, corresponding to a factor of 1.3 in relation to the control channel power. Taking this into account, one can calculate the total power of all BTS to:
84,700 BTS x 3 sectors x 1.3 (channel factor) x 8 W each channel = 2.6 MW.
In relation to the area of Germany this results in an average power density of 7.3 ?W/m2.
This number has only slightly increased compared to the calculations reported in [WUS 04] for 2004 despite of the growing number of new BTS. This is due to the fact, that most of new BTS are UMTS stations, which have a better relation of permanent signalling power to the maximal power with regard to exposure compared to GSM stations.

Average exposure from Mobile Phones
As of the end of 2005, Germany has had approximately 74.3 million mobile phone customers (T-Mobile: 28.2 million, Vodafone 27 million, E-Plus 10.1 million and O2 9 million). To multiply this number by 2 W for GSM 900 and 1 W for GSM 1800, respectively, to get the total emitted power, would lead to confusing results. (1) The mobile phone powers of 2 W or 1 W are maximal time slot powers and not averaged in the GSM TDMA scheme, and (2) due to usage time, power control and DTX the averaged emitted power in reality is much smaller.
Concerning typical mobile phone times, a number of 118 million minutes in total per day is evaluated in [DIA 05] for the year 2005. This number holds for calls going from mobile phone users into the mobile phone net as well as into the fixed network. Assuming that in average the ingoing calls to mobile phone users are in the same order of magnitude, a total number of 236 million mobile call minutes each day would result. This number does not include the content of data services, which is evaluated in [DIA 05] to 20 % of the sales volume. For the sake of simplicity the 20 % are added to the number of call minutes for the outgoing calls, giving in total a number of 260 million minutes each day.
Concerning the average transmit power of mobile phones including parameters like power control and regulation mechanisms for cell handovers, in [Geo 05] a time averaged power of
0.06 W was measured for connections during car drives. This number has to be weighted by a factor of 0.6 for DTX, resulting in a value of 0.036 W. Similar values were obtained for inhouse applications with locaten fixed users. In [Wia 00] a number of 0.062 W was obtained for Paris in 2000; here the former state of the GSM BTS network may have led to these higher results. In [Wus 05] numbers between 0.0135 W and 0.1365 W (including DTX) were obtained during several measurements in the city of Passau. These results show a large variability; for the budget comparison performed here an average value of 0.04 W will be used.
Under these assumptions, the following calculation can be performed:
260 mio call minutes per day / 1440 minutes (total minutes per day) x 0.04 W = 7.2 kW.
In relation to the area of Germany this results in an average power density of 0.02 ?W/m2.
Conclusion The average exposure resulting from cellular mobile phone base stations is by a factor of 360 larger that the exposure due to mobile phones. It should be noted, that this is a global budget comparison and does not represent the individual or location based exposure.

Basic Question
Question
The basic question to be answered in this work package concerns the comparison of the exposure due to mobile phones and Base Transceiver Stations.
Answer
Whereas the BTS transmit more power as a mobile phone as far as single devices as well as the total of all devices in operation in Germany is concerned, the individual exposure is dominated by the mobile phone at least when the mobile phone user is observed. Moreover, there are many situations, where "uninvolved" people (i.e. people not using a phone) are higher exposed by nearby mobile phones of other users than by surrounding base stations. These scenarios are likely inside trains or cars, conference rooms, lounges or airport terminals, exhibition halls, office environments and general queues of persons..."

Troll-Wiese: http://www.izgmf.de/scripts/forum/index.php?mode=entry&id=26446

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Miniwatt