Start with the map, then read the numbers with care

Open the map, search your address, and raise the fan opacity so the nearest masts are obvious. Clicking a mast shows the operator, the network generations, the power class, the azimuth of each sector and the modelled estimate at that spot. The pointer readout follows the cursor and reports both the single nearest mast and the total of everything in range, so you can compare a fan's own edge with what the ground actually receives there. Combined field in the settings shows that total as one picture instead of one fan per mast. Then use Radiation levels to see how that value compares with the Swiss installation limit, international guidelines and the much stricter limits some scientists propose.

Two things stay true whichever way you read it: the shaded field is a model, not a measurement at your address, and the model is deliberately a worst case. It assumes every antenna transmits its permitted maximum at all times, in your direction, with no buildings or terrain in the way.

What the map genuinely answers

• Which masts are closest to a given address, who runs them, and which generations they carry.
• Which direction each sector points — useful for judging whether you sit in a main beam or behind it.
• Where in Switzerland the modelled field is high, moderate or low, at national and street scale.
• How much the picture changes between technology generations, operators and power classes.

What the map cannot answer

• The actual exposure at your window, desk or bed. Only a calibrated measurement can tell you that.
• Health risk. Exposure estimates are not a diagnosis and this site is not medical advice.
• the effect of walls, roofs, terrain and vegetation, or how much traffic the network was carrying at the moment of interest.

If you want a real number

Ask your canton's environmental or labour inspectorate for a measurement, or commission a qualified measurement service. Cantonal offices are responsible for enforcing the NISV installation limit values and in many cantons a measurement can be requested. A measurement report tells you the field strength in V/m at a defined point, with a defined instrument and averaging time — which is the only basis for a discussion about limits.

Practical, uncontroversial steps

Distance is the single most effective lever: field strength falls off with the square of distance, so moving twice as far away makes the modelled value about four times lower. Wired connections for fixed devices reduce the number of nearby transmitters, and mobile phones transmit far more strongly when reception is poor, so better reception usually means lower exposure from your own handset. None of this requires believing anything in particular about health effects, and none of it is a substitute for a measurement if you need one.

Can a community refuse a mast?

Short answer: a majority of residents saying no does not, by itself, stop an antenna. That surprises people, and it is worth understanding exactly why — because the rules also leave more room to act than the headline suggests.

A new mobile installation needs a building permit in every canton. The application goes through the ordinary procedure, it is published, and anyone within the objection perimeter can lodge a public-law objection. The authority then assesses the project against building and planning law and against the NISV radiation limits. If it complies, the permit is issued: a petition, a municipal vote or the mood of a village meeting is not, on its own, a legal ground for refusal. Federal case law has confirmed that repeatedly.

The uncomfortable part is that this is not an accident of how the rules were written. Radio coverage is a federal matter, and a community cannot opt out of it any more than it can refuse a railway that has already been through the planning process.

What an objection can achieve

• Standing depends on radiation, not on distance in metres. You can object if you live, own property in or work in a space where the installation can produce at least 10% of its installation limit value: dwellings, school rooms, kindergartens, hospitals, care homes, and permanent workplaces occupied more than 2.5 days a week. The perimeter therefore differs for every antenna, and it counts even where the installation itself stands in the neighbouring municipality.
• The strongest grounds are technical. The NISV limits apply in every canton, so a project that exceeds them — or whose site data sheet is wrong, incomplete or based on the wrong operating assumptions — can be stopped on that basis alone. Beyond that, the admissible grounds differ from canton to canton.
• Procedure matters more than it sounds. Minor changes, such as a like-for-like antenna replacement or reallocating power between existing panels, can be handled as a simplified case in which neighbours have no party rights at all. Where such a change should have gone through the ordinary procedure, requiring that it does is itself a legitimate step.
• The deadlines are strict and cantonal. A published application has an objection window — typically a few weeks — that runs whether or not anyone is watching the communal gazette. Missing it usually ends your involvement in that case.
• Appeals run through the cantonal courts and can reach the Federal Supreme Court. A contested project can therefore take years. In practice that delay, rather than the objection itself, is often what changes an outcome.

Where municipalities do have power

A municipality cannot override federal telecommunications and radiation law, but siting is planning, and planning is largely local. That lever is real, and it has been litigated to the top of the court system:

• Siting rules in the building and zoning regulations. A municipality can require installations in designated areas, or restrict them in residential zones. Courts have accepted restricting antennas in residential zones in order to preserve the character of the zone.
• A planning zone. While it revises those rules, a municipality can suspend decisions on new installations for a limited period so the question can be settled properly. Several cantonal courts have upheld exactly that.
• The limits of the lever. Planning measures must serve a genuine planning purpose and be proportionate. A rule whose only function is to keep out installations that are already technically compliant and visually imperceptible has been set aside.

The honest summary: radiation limits are federal law and the same everywhere, siting is planning law and differs from one municipality to the next, and residents' influence lives almost entirely in the second of those.

This is general information about a procedure that varies by canton, not legal advice. Cantonal NIS offices publish local guidance and the deadlines that apply there, and a lawyer specialising in building and environmental law can assess a specific case.

Choosing a place with less exposure

If your goal is a home with little radio-frequency exposure, the strongest variable is not the country and not the national limit value — it is the specific municipality and the specific plot. Swiss limits are already among the strictest in Europe, and they still do not give a village a veto; a country with looser limits can leave your house a kilometre from the nearest mast, or right beside one.

Start with the geography on this map: search an address, raise the fan threshold, and look at which masts are near and where they point. Then check what a map cannot show you.

• Existing sites in every direction. The federal BAKOM register and this map list them. What matters is whether a sector points at the plot you are considering, not how many masts the municipality has in total.
• Pending applications. Building applications are published in the cantonal gazette and are held by the cantonal NIS office. A quiet valley with an application pending next door is not a quiet valley.
• The municipality's planning rules. Does it have siting rules, a planning zone, or a revision under way? That is where local influence shows up in practice.
• Topography. A site in the next valley can matter less than a closer one on the same ridge line. This model deliberately ignores terrain, so treat its output as geometry rather than as shielding.
• What follows traffic. Capacity installations follow demand: motorway corridors, rail lines, industrial areas, hospitals and large workplaces attract them; a valley with no through traffic does not.
• Your own equipment. A handset or router working hard to reach a distant mast can contribute far more at close range than a base station hundreds of metres away, which is why reception quality and a wired connection matter.

None of this is specific to radio: it is the same due diligence you would apply to noise, a flight path or a planned road. It is also why this site shows estimates with their assumptions written out rather than a single comfortable number.

Comparing countries

A country-by-country table of limit values is a poor guide on its own, because limits differ in kind and not only in size: per installation or summed over all operators, averaged over six minutes or over a day, at one frequency or across a band, at places of sensitive use or everywhere people may be. A stricter-looking number in one country may be a cumulative figure for one band, while a looser-looking number elsewhere may apply to each antenna separately. The structure differs too — Belgium, for example, sets limits per region rather than nationally. The values and their definitions are on Radiation levels.

Physical distance is usually the more decisive factor. In a sparsely populated valley the distance to the nearest installation can matter far more than the ratio between two national limit values, and that distance is something you can check before you buy rather than after. If you are weighing countries, weigh the municipality and the plot first, then read the current rule published by that country's responsible authority instead of a headline figure from a comparison table.

Two positions, both represented here

Two ways to write the same thing

Ambient radio-frequency exposure is usually written either as power density (S, in W/m² or µW/m²) or as electric field strength (E, in V/m). For a single plane wave in the far field they are locked together by the impedance of free space:

S = E² / 377   ·   µW/m² = E² × 2 652

µW/m² means microwatts — millionths of a watt — per square metre. 0.04 W/m² is 40 000 µW/m², not 40 milliwatts: the unit describes a power per area, not a total power.

The limits that actually apply in Switzerland

Swiss law (the NISV ordinance) uses two different values, and they are ten times apart:

• Installation limit value (Anlagegrenzwert, 4–6 V/m depending on frequency): the binding value for each individual mobile installation, applied where people stay regularly — dwellings, schools, hospitals, offices.
• Immission limit value (Immissionsgrenzwert, derived from the international ICNIRP reference levels, roughly 40–61 V/m in the mobile bands): the value for the total exposure from all sources at any place where people may stay.

The installation limit is what makes the Swiss approach precautionary by international standards: it is up to ten times lower than the immission limit, and each installation is judged on its own rather than on the sum.

What is actually measured in Switzerland

The federal government measures exposure itself. In the third national measurement report (published May 2025), the highest single value recorded anywhere was 0.48 V/m at an airport, and the medians were 0.08 V/m at schools and 0.09 V/m at village centres. Converted, that is roughly 610 µW/m² at the very top of the distribution and about 20 µW/m² at a typical village centre — far below every limit in the tables above.

How this map's numbers compare with those

This map does not measure anything. It calculates an upper bound from the power class BAKOM registers for each installation. Each mast is given a path-loss profile that never attenuates less than free space, so the figure is bounded by the free-space one, and the model deliberately contains none of the things that reduce real exposure.

How far out can one figure be? Roughly a factor of two — treat any single number here as "of the order of", never as a reading. That is not one error term but several, and they pull in different directions. The power class is a permitted maximum rather than what the site transmits, which is the largest single factor and always pushes the figure up. The mast height, the down-tilt and the vertical beam are three nationwide constants standing in for per-installation values, and a real installation can sit above or below all three — a site tilted far down puts more of its power into the ground near itself than the model assumes, one tilted barely at all puts less. And the vertical pattern is a single idealised shape for every panel in the country. Three of those biases run upward, which is why the result is an envelope overall, but the tilt and height assumptions can move an individual site's ground-level figure in either direction. So the useful content of the map is the comparison — which places are higher, which sectors face where, and by roughly how much — and the absolute figures are offered at about the precision a factor of two allows.

Taken over the 2,123 municipality centres — the inhabited point of each, which is what the settlement table leads with — the modelled field, under the shipped automatic model, has a median of about 0.2 V/m: two to three times the measured village medians above, and still below the highest single value that programme has ever recorded. The busiest town centres read in the mW/m² range: the model puts the densest city squares at 1.7–3 V/m, and the very busiest — a main station forecourt, a stadium — higher again. Most centres read below the 200 µW/m² shipped threshold — so the exposure layer is dark over most of the country, amber where the installations are dense, and empty altogether in the Alps and on the passes. Those figures are to be read as an envelope rather than an estimate: the same places measure well under 0.5 V/m in the federal programme.

That gap is not a calculation error. It is the sum of what the model leaves out or has to assume, each item of which only ever adds:

• Class power, not operating power. The inventory gives a power class — up to 6 W, 500 W, 5 000 W, or more than 5 000 W — and the model uses the top of the class. An installation is normally configured well below its permitted maximum, and its actual output at any moment depends on traffic.
• A vertical pattern built from nationwide constants. The beam is tilted below the horizon and its gain does fall away above and below that axis, so the beam's axis meets the ground about 140 m out at the assumed 16 m mast height, the modelled field is strongest near 85 m where that gain and the falling path term balance, and the ground directly beneath a mast is a weak position, as measurement finds. What no public file carries is the real mast height, down-tilt, vertical beamwidth or panel pattern, which are per-installation values: one set of constants (16 m, 6°, 10°) therefore stands for every mast in the country, and a real installation may be above or below them.
• No buildings, terrain or vegetation. Walls cost 10–20 dB or more, ground clutter and hills cost more. None of it is here.
• Everything transmits at once, at full power. Every installation whose own fan covers the point is added together as if all of them were at their maximum simultaneously — 101 masts stand within 500 m of Zurich main station and 7 of their own contours cover the point; at the Wankdorf stadium the same two figures are 31 and 4. A place where nothing covers it reads below the threshold instead: a summit or a ridge in the Alps reads essentially zero here, which is what the map shows there.
• One cut-off, shared by the colours and the numbers. A mast contributes only out to three times its own contour radius, because that is as far as the map draws it. Past that the contribution is small — an eleventh of the threshold or less from any single installation — but there are thousands of installations, and summing their tails regardless was what once made a village with no fan over it read twice the threshold while the map showed it as quiet. The figure you read under the pointer is now the same quantity that is painted under it, which is a cut-off you can check by eye and a lower bound on the true sum.

So read the map as a comparison, not as a measurement: it is good at showing where exposure is higher or lower, which direction a sector faces and how close the nearest installations are. The absolute figures are an envelope that reality sits well below — by a factor of roughly two to three at the median centre and by an order of magnitude where the model is loudest — and they should not be read to better than about a factor of two either way. Two numbers worth keeping in mind: the shipped threshold is 200 µW/m², or 0.27 V/m, a little above the modelled median centre; and 500 µW/m² (0.43 V/m) is just under the highest value the federal measurement programme has ever recorded anywhere in Switzerland.

Is the ordering right? Named places, checked

A model can be too high everywhere and still be useless. What matters is whether it puts the right places in the right order and by a defensible margin, so the summed estimate is sampled at ten named locations by the verification harness, at the same 25 m reference distance the rest of the map uses. Every figure below is a worst case on the model's own assumptions, not a measurement:

• Matterhorn summit 0.00 V/m, middle of Lake Lucerne 0.00 V/m, Jura ridge 0.00 V/m — the three places in the sample with no installation within a kilometre. All three read zero at the shipped settings: the summit and the lake because no installation's own contour reaches them, and the ridge because its nearest mast is 1.4 km away and the summed field is not carried that far. These are figures for the map as it opens — the reach of the sum follows the threshold and the model — so they are quoted at the shipped default rather than as properties of the place.
• Grimsel pass 0.33 V/m and Vals village centre 0.75 V/m — a high pass with a handful of masts, and a 1,000-resident alpine village. The village reads several times the measured village-centre median, which is the envelope this model is built to be.
• Glarus town centre 0.66 V/m, Wankdorf stadium, Bern 0.80 V/m, Basel Marktplatz 1.58 V/m, Zurich main station 1.44 V/m, Zurich Bellevue 2.95 V/m — the densest places, where dozens or hundreds of sectors stand within a few hundred metres of the sample point and the sum is at its loudest. Nothing here is a measurement; the measured maximum anywhere in Switzerland is 0.48 V/m.

The ordering is what a reader would expect from the inventory and from the published measurements: open ground lowest, a village in the middle, dense towns highest, with the model's over-estimate growing exactly where the assumptions bite hardest — many overlapping installations, all assumed to transmit at their permitted maximum at once, with no buildings in the way. The harness prints the full table, including how many masts stand within 500 m of each point and how many of their contours cover it, so the figures can be traced back to the inventory rather than taken on trust.

Fans, or the summed field

One view draws one fan per antenna, and a fan is that installation's own threshold contour: its edge is where that mast alone falls below the level. That is the readable view, and it is deliberately not the quantity a person at a point is exposed to. Two masts that each deliver 300 µW/m² show two fans that stop short of a 500 µW/m² line while the ground between them is over it, because the field is a sum.

Combined field — the view the map opens in — is that sum: the same model evaluated once per pixel with every mast added, painted from the summed value and bounded by the summed field's own contour, drawn as a single black line. Measured at Zurich at zoom 11 and the default 200 µW/m² signal threshold — the same control the fan view uses, so the two are directly comparable — the summed region covers 44% of the view against the 26% the fans cover, and 41% of it is ground that no fan reaches — the part that only exists because contributions add. It is the heavier view, and the raster is sampled more coarsely to keep the frame inside the same budget — the price of it being the shipped default, since it is the quantity the readouts report. The sum is accumulated out to three times each fan's radius; past that a mast contributes an eleventh of the threshold or less, so the view slightly under-states the field in open country, which is the safe direction for the one number on this site that people act on.

The low-exposure disks are drawn one per settled place — every OpenStreetMap place node in Switzerland with a settlement class, 15,174 of them: 10 cities, 166 towns, 3,502 villages, 6,839 hamlets and 4,657 isolated dwellings (single farmsteads, the quietest addresses in the country) — and each one's radius is the distance from that place to the nearest ground the map paints above the threshold, so a rim is tangent to the coloured region on screen and none is drawn over ground the map has already coloured. The two views get that distance differently, and the difference is the reason it can be checked with a ruler. In the per-mast view the boundary is a fan contour the model solved, and the distance to it has a closed form: exact, at any zoom, and independent of what happens to be on screen. In the combined view the boundary is the summed field's own contour — which depends on every mast at once and has no closed form — so there it is read off the raster that was just painted, and a place whose nearest contour lies outside the frame has no disk at that zoom. A place the map already colours gets no disk in either view, which is the honest answer rather than a missing one. Measuring the remaining places is about a second of arithmetic, worked through in slices rather than in one call, so a threshold change never freezes the map — the layer fills in over roughly a second and nothing is recomputed while panning or zooming. Where two disks overlap they are filled as one union, so the shared ground takes the same tint rather than doubling it, and neither rim is drawn across the other's fill: that overlap is not a boundary the model measured. The settlement's name is redrawn over the wash in the tile's own style and at its own coordinate, because a translucent wash over a place label is exactly what makes the name unreadable. The layer can also be drawn the other way round — Everywhere washes every area below the threshold in green instead of drawing one disk per place. It trades the checkable rim for covering the whole country at once, including the places whose nearest contour lies outside the current frame and the ones whose rim would have nothing on screen to land on; it is the complement of the amber by construction, so no pixel is ever both, and it has no rims to click.

How the published guidance levels compare

Below about 2 GHz the international reference level falls with frequency, so at 900 MHz the ICNIRP value is about 4.5 W/m² (≈41 V/m) rather than 10 W/m². That is why Swiss and German limit tables list different numbers for different bands.

Do other countries allow less?

Some do, and the comparison is easy to get wrong. National limits differ not only in value but in definition: per installation or summed across all operators, averaged over six minutes or over a day, at a fixed frequency or across a band, at places of sensitive use or everywhere people may be. A single number taken from another country is therefore not directly comparable with the Swiss installation limit, which applies to one installation at a time at sensitive locations.

What can be said precisely: the Swiss installation limit is roughly ten times stricter than the Swiss immission limit, and the immission limit follows the international ICNIRP reference levels. Several countries and regions have adopted precautionary values in the same range as the Swiss installation limit or below it, and several have no additional precautionary value at all. The regulatory structure varies as well — Belgium, for instance, regulates per region (Flanders, Wallonia and Brussels) rather than nationally.

For any specific country, use the current rule published by the responsible authority, and check which definition it uses before comparing it with the figures above. For the separate question of how easily a community can keep an installation out, see Radioguard — how strict a limit is and whether a village can refuse an installation are two different things.

What measurements usually find

Federal and cantonal measurement programmes in Switzerland repeatedly report ambient outdoor values far below the limits. Published medians for dwellings and schools typically fall in the range of roughly 0.02 to 0.1 V/m (about 1 to 30 µW/m²), with the highest single values in dense city centres or close to an airport in the range of a few tenths of a volt per metre. In other words: most measured places sit below even the strictest precautionary proposals, while individual spots in a main beam can exceed them.

Why the map shows bigger numbers than that

The shaded field on this map is an upper bound rather than a prediction. It adds the permitted maximum power of every nearby sector, in the direction of the point, with no buildings, no terrain, no vegetation and no allowance for the fact that a network almost never transmits at full power. That makes it useful for comparing places and directions, and unsuitable for reading as a measured value. Use the numbers from the panel and the popups to rank what is near you, not as an absolute exposure figure.

The vertical pattern is modelled, and it is what makes the numbers near the ground behave. A macro panel stands tens of metres up and is aimed at or slightly below the horizon, so its beam is only about 7–10° tall, and a person on the ground fifty metres out sits 10–30° below that beam, where a real panel radiates twenty decibels or more below its maximum. The model therefore assumes a 16 m mast, a 6° down-tilt and a 10° vertical beam, which puts its strongest ground ring about 140 m out and makes the ground directly under a mast a weak position rather than the strongest one. What it cannot carry — because no public file publishes them — are the real height, tilt, vertical beamwidth and panel pattern, which differ from installation to installation. Figures very close to a mast are still the least reliable on the map, so a large reading should be read as the top of a wide range rather than as an estimate. The permissioned BAKOM sector export would replace those three constants with each installation's own values.

The rest of this site answers one question: what does the mobile network put into the air at a given point? For most people that is not the only radio-frequency source in their day, and for many people it is not the largest one. This page puts the mast in context.

One fact decides most of it before any number is quoted. Field strength falls with the square of distance, so ten times further away is a hundred times weaker. A mast is permitted hundreds to thousands of watts and stands a hundred metres away or more; a handset is a fraction of a watt centimetres from your head. Those two facts pull in opposite directions, and the arithmetic below is what settles it.

Uplink and downlink — the two directions of "normal phone connectivity"

A mobile link runs both ways, and the two directions are not the same exposure at all:

• Downlink — the mast transmits to your phone. This is what this map models. It runs continuously, whether or not anyone is using a phone, and it is the exposure a person who does not own a mobile phone still receives.
• Uplink — your phone transmits back to the mast. It runs only while the phone is actually sending, it is a small fraction of a mast's permitted power, and it is radiated from an antenna centimetres from your hand or your ear. For that reason it produces the highest exposure at the body of anything on this page.

The network sets the handset's uplink power and lowers it as reception improves; that is what the power-control signalling between mast and phone is for, and it is why battery life improves where the signal is strong. The practical consequence is worth stating plainly: the exposure from your own handset is the part of it that responds to what you do. A basement, a deep valley, a train carriage with metallised windows or a thick-walled building all force the phone to transmit harder, and improving reception — a call over Wi-Fi, a window, a different room, a wired connection — reduces it.

Because the handset radiates into your body at a distance of centimetres, its exposure is not expressed as power density but as SAR (specific absorption rate): watts absorbed per kilogram of tissue, limited internationally to 2 W/kg averaged over 10 g for the head and trunk. A mast a hundred metres away is a plane wave, and power density is the right measure for it — which is why this page quotes both and never converts one into the other.

What each source may transmit

These are regulatory maxima and typical values — what a device is allowed to do, not what it is doing at this moment. A device at its maximum has to be doing something: holding a call, streaming, or reaching across a house.

The mast row is the one the register states precisely. Every installation in it is filed in one of four power classes, and the class is a permitted maximum rather than what the site transmits: of the 22,482 register rows behind this map, 4,433 rows are ≤6 W, 3,249 are ≤500 W, 13,070 are ≤5,000 W and 1,730 are above 5,000 W. So a single mast is permitted four to eight orders of magnitude more power than a router — and it also stands a hundred to several thousand metres away, which is the whole of the comparison.

The same arithmetic at a distance

Field strength and power density are locked together by the impedance of free space, and a transmitter's power spread evenly over a sphere of radius d gives a power density of P / (4πd²). That is the same intermediate quantity this map's model starts from, so the table below is the map's own yardstick applied to everything on the page.

Two dashes and one column need explaining. A dash means the distance is not a meaningful one for that source: you cannot stand a metre from a mast's antenna, which is metres above you, and at those ranges the plane-wave formula stops describing a nearby device as well. The column of dashes is the same point from the other side — a mast's numbers at 100 m and 1 km assume a clear line to the beam's axis, and the map's model does better than that, applying the panel's vertical pattern so ground level below the beam reads far lower. That vertical pattern is also why the map's contours stop closer in than this table suggests, and it is the reason the strongest modelled ground-level ring around a mast sits about 85 m out rather than at its foot.

As a check on the arithmetic rather than on the physics: the highest outdoor value the federal measurement programme has ever recorded anywhere in Switzerland is 0.48 V/m, which is about 610 µW/m². A Wi-Fi router at its permitted 100 mW produces that at roughly 3.6 m. A typical Swiss village centre as measured — 0.09 V/m, about 22 µW/m² — is what the same router produces at roughly 19 m. Neither figure is an argument that routers are dangerous; both are a scale against which the federal measurements can be read.

The one number that makes them comparable

Everything above reduces to a single question: at what distance does each source produce the level this map draws its contours at, the shipped 200 µW/m² default? In the same free-space arithmetic, before any beam pattern is applied:

• a Bluetooth class-2 device — a keyboard, earbuds, a watch — about 1 m;
• a Wi-Fi router at its permitted 100 mW — about 6 m;
• a 5 GHz access point at 200 mW — about 9 m;
• a DECT cordless phone at 250 mW — about 10 m;
• a mast in the very-low class, up to 6 W — about 49 m;
• a mast in the low class, up to 500 W — about 450 m;
• a mast in the medium class, up to 5,000 W — about 1.4 km.

Both halves of that list carry a qualification, and the comparisons only work with them in place. The masts' distances are quoted before the vertical pattern, which the map applies; ground level is well below the beam's axis, so a fan on the map is rarely as long as the free-space distance. And "at its permitted maximum" is a real qualification for the small devices: a router transmits at 100 mW when it is holding a long range on a busy channel, and far less, in short bursts, when it is idle two metres from the device it serves.

What measurement finds next to them

The figures below are published measurements, not model output, converted to power density using the same relation the rest of the site uses.

The shape of that table is the answer to the question this page exists for. The largest measured numbers in an ordinary day come from devices within a metre of the person, not from masts — and the numbers next to masts are the smallest in the table. That is not a claim that a mast is harmless, and it is not a claim that a router is the thing to worry about either. It is simply where the exposure sits.

The World Health Organization reaches the same conclusion from the measurement side: in publicly accessible places, including schools and hospitals, outdoor exposure from base stations normally comes out thousands of times below the international reference levels, and is lower than or comparable to exposure from radio and television broadcast — which the body absorbs up to five times more of at the same field level, because those frequencies are lower and a person's height makes them an efficient receiving antenna.

Two limits put the table above in proportion. The international reference level for the general public across these bands is 61 V/m at 2 GHz and above, and about 41 V/m at 900 MHz — between fifty and a hundred times the highest measured value in this country. The Swiss installation limit is far stricter, 4–6 V/m at sensitive locations, and the smart-meter and router readings above do sit within a factor of a few of it: that is not a coincidence, it is why the Swiss approach is often described as precautionary, and it is also why a reading taken at 30 cm from a device says very little about the same device at two metres.

Bluetooth, Wi-Fi 2.4 GHz, Wi-Fi 5 GHz and mobile data, side by side

• Bluetooth is the least powerful of the group by one to two orders of magnitude — 2.5 mW on the class most keyboards, earbuds and watches use, against 100 mW for Wi-Fi — and it sends in short bursts rather than continuously. At a metre, while it is transmitting, it produces about the level this map draws as its threshold; averaged over a day it is a small fraction of that.
• Wi-Fi at 2.4 GHz shares its band with Bluetooth, microwave ovens and every neighbour's router, which is why a router often sits at its permitted 100 mW to hold range. It passes through walls better than the higher band.
• Wi-Fi at 5 GHz is allowed two to ten times more power, and is absorbed much more strongly by walls and by water — people included. In the same room at the same distance it reads roughly twice the 2.4 GHz level; through a wall it reads considerably less. Its shorter range follows from the same property.
• Mobile data — the 4G and 5G uplink — is bracketed by the network between roughly 0.12 and 0.2 W averaged, and the antenna is against your hand or your head rather than across a room. Its most useful property is that it falls as reception improves, so it is the one item here that a change of position reliably reduces.
• 2G voice, still the layer the railway installations in the register are filed under, is where handset peak powers are highest: up to 2 W per pulse at 900 MHz, though time-averaging over the frame brings that to 0.25 W.

None of these can be ranked by a single number, and the reason is worth keeping in mind. A mast, a router and a cordless base station radiate into the air at a distance, so power density describes them. A handset and a smart meter in your hand radiate into you, so SAR does. Converting between the two is not a unit change but a category error, which is why the two measures appear side by side on this page and are never added together.

References

• World Health Organization — base stations and wireless technologies →
• German Federal Office for Radiation Protection (BfS) — wireless applications in everyday life: Bluetooth, Wi-Fi, DECT, Zigbee, LoRaWAN and UWB power limits →
• German Federal Office for Radiation Protection (BfS) — mobile terminals: handset transmit power and SAR →
• Irish Environmental Protection Agency — Wi-Fi, smart meters and your health, with measured levels →
• ICNIRP — radiofrequency EMF guidelines, 100 kHz to 300 GHz →
• ARPANSA (Australia) — radiofrequency radiation, and how exposure falls with distance →

Measured Swiss values are the federal measurement programme's, as set out on Radiation levels · external links are references, not affiliations, and carry rel="nofollow"

What is established

At high intensity, radio-frequency energy heats tissue. That effect is well understood and measurable, and the international reference levels exist to keep public exposure far below the level at which heating occurs — typically with a safety factor of fifty for the general public. Below those levels, the large majority of expert reviews, including the World Health Organization's assessments and the ICNIRP 2020 guidelines, find no established adverse health effect.

In 2011 the International Agency for Research on Cancer classified radio-frequency electromagnetic fields as possibly carcinogenic to humans (group 2B). That classification is based mainly on limited evidence from long-term mobile phone use, where the phone is held against the head and tissue absorption is far higher than anything a base station produces. Group 2B is a hazard classification, not a statement about base-station exposure, and it sits in the same category as coffee and pickled vegetables.

What is genuinely uncertain

• Whether any non-thermal biological effect exists. Some laboratory studies report oxidative stress or changes in cell behaviour at low intensities; others do not reproduce them, and the results are not consistent enough to support a causal claim.
• Whether very long-term, very low-level exposure has any effect at all. The epidemiology here is hard: exposure is difficult to estimate retrospectively and mobile use patterns change faster than studies can follow.
• Whether the shape of 5G signals — beam steering, higher peak-to-average ratios — changes anything. Present evidence does not show a difference in biological effect at comparable average exposure, and measurements in Switzerland and elsewhere have found average 5G exposure in the same range as 4G.

The precautionary argument

A substantial minority position, held by some researchers, medical organisations and public-health advocates, is that "no established effect" is not the same as "no effect", and that limits which are set purely to avoid heating are not protective enough. Precautionary proposals such as the Salzburg Resolution (1 mW/m²) and the BioInitiative Report (5 µW/m²) follow from that position, and several countries and regions write stricter limits into law. The Swiss installation limit value, ten times below the international immission limit, is itself an expression of the precautionary principle.

About the BioInitiative Report

The BioInitiative Report is the most frequently cited source for very strict limits. It was first published online in 2007 and updated in 2012 by a self-selected group of authors led by Cindy Sage and David Carpenter, and its central recommendation is an outdoor cumulative limit of 5 µW/m² — two thousand times below the ICNIRP reference level for high frequencies.

It is also criticised heavily. It was not peer-reviewed, the Health Council of the Netherlands concluded that it is a selective review of existing research rather than a balanced analysis, and former ICNIRP officials have described it as advocacy rather than objective assessment. This page reports it because people genuinely rely on it, not because it represents a scientific consensus.

Electromagnetic hypersensitivity

Some people report headache, sleep disturbance, fatigue, skin sensations or difficulty concentrating that they attribute to electromagnetic fields. The WHO recognises these symptoms as real and potentially disabling, while noting that controlled provocation studies have not shown that exposure reliably triggers them; it recommends treating the symptoms and reducing exposure where a person finds that it helps. Whether or not the mechanism is electromagnetic, the distress is not imaginary, and this map is meant to be usable by people who experience it.

Where this site stands

Main sources to read next

• World Health Organization — electromagnetic fields and public health: base stations and wireless technologies →
• ICNIRP — guidelines for limiting exposure to electromagnetic fields, 100 kHz to 300 GHz, 2020 →
• IARC — monograph volume 102 on radiofrequency electromagnetic fields, 2013 →
• The BioInitiative Report →, and the critical reviews by the Health Council of the Netherlands and other national bodies.
• Swiss Federal Office for the Environment and the Federal Office of Communications — NISV guidance and the federal measurement reports, quoted on Radiation levels.

External links are references, not affiliations, and carry rel="nofollow"

OpenCelliD, in figures

OpenCelliD is a crowdsourced database of mobile cells, run by Unwired Labs, and it is the largest openly published collection of its kind: records of which cell a phone saw, where. It covers the whole world rather than one country, and its operators publish a statistics page that is updated continuously. The figures below are a snapshot taken on 17 September 2026; the live table is on their page, linked at the foot of this one.

The remainder is GSM (2G), UMTS (3G) and a small number of CDMA records. A few countries, chosen to show the range rather than to rank anyone, with Switzerland for comparison:

• Germany — 3,180,507 cells
• France — 2,657,486 cells
• Spain — 1,152,068 cells
• Austria — 629,611 cells
• Switzerland — 347,358 cells: 75,799 GSM, 142,557 UMTS, 127,551 LTE, 1,451 NR

What those numbers are, and what they are not

They are logical cells observed across the history of the project, not installations. Its own page is careful about this and so is this one: a logical cell is a carrier, a band and a sector identity that some phone recorded; several of them can sit on one physical antenna, and a cell that nobody has ever had a reason to record may be missing entirely. The database states that logical cell counts only loosely correlate with physical towers, and that its exports include only data observed in the last 18 months — so the totals are a picture of what has been seen recently, not a register of what exists.

That is the difference from the data this map draws. The Swiss register used here is an administrative one: which installations are permitted to transmit, where, with what power class. A crowdsourced database is an observational one: which cells somebody's phone noticed. Both are useful, they answer different questions, and neither can be converted into the other by dividing one by the other. Switzerland appears in OpenCelliD with about 347,000 cells against the roughly 22,500 installations in the official register — a ratio that reflects how many sectors, bands and carrier layers each site runs and how much of it has been recorded, not how many masts stand in the country.

For a reader who wants to compare exposure rather than count hardware, the useful point is that coverage is not a proxy for exposure. Two countries with the same number of cells per square kilometre can differ by an order of magnitude in the power a person actually receives, and the figures on this page say nothing at all about how much field strength anyone lives in. The modelled map is the place to ask that question, and its Radiation levels page is where the measured Swiss values are.

Why this is a snapshot and not a live feed

Two reasons, one technical and one about doing the right thing by somebody else's work. This site is a set of static files: there is no server of ours to fetch a page on a schedule, and the statistics page does not offer a cross-origin API, so a browser cannot read it directly either. An embed — framing their page inside this one — would load their servers on every visit to ours, would break the moment they changed their markup, and would present their numbers as if they were part of this site. So the figures are quoted, dated, attributed and linked.

On the rights of it: aggregate figures are facts and are not copyrightable, so quoting a dated snapshot with attribution is ordinary practice and is what is done here. The database is a different matter — OpenCelliD publishes its data under its own open terms, and anything built from the records themselves should be taken from the source and keep those terms. Nothing on this page is copied from it beyond the totals shown above, and this site is not affiliated with OpenCelliD or Unwired Labs and implies no endorsement in either direction.

OpenCelliD statistics, live — opencellid.org/stats.php →

Figures as published on 17 September 2026 by OpenCelliD / Unwired Labs · quoted with attribution · nofollow link, no affiliation

OpenStreetMap + BAKOM inventory · 5G + 4G + 3G · automatic per-site model

How the map is built

Antenna positions come from the official Swiss inventory of mobile installations published by the Federal Office of Communications (BAKOM), loaded here as a local snapshot of that dataset: 22,482 register rows — one per installation and technology group, over 20,853 distinct coordinates — with their coordinates, operator, technology generations and permitted power class. 21,261 of those rows carry a generation this map models and are drawn. The other 1,221 are 2G-only, and all 1,201 SBB railway installations are among them: the map draws no 2G, so those appear on no dot, in no popup and in no figure. See What is included, and what is not below. The basemap is OpenStreetMap. The shaded field is computed in your browser from those two inputs.

Two things are computed from that model, and the settings panel chooses which is drawn. Per-mast fans is one threshold contour per antenna: an edge you can trace back to a single installation. Combined field (the default) is the sum of every mast, painted and contoured as the ground actually receives it, which is the same quantity the popups, the pointer readout and the settlement figures use. See Fans, or the summed field below for what the two look like side by side.

Loading official inventory…

For every site the model takes the permitted power class, the sector azimuths from the bundled sector snapshot, an assumed 65° half-power panel width and a free-space path-loss model, then adds the contributions of all nearby sectors at each point on the screen. On top of that horizontal pattern it applies a vertical one: the beam is assumed tilted 6° below the horizon from a 16 m mast with a 10° vertical beam, so the beam's axis meets the ground about 140 m out, the modelled field is strongest a little closer in, near 85 m, and the point directly beneath a mast is a weak position rather than the strongest one. Each sector's fan is that sector's own threshold contour, solved along every ray instead of drawn as a wedge: it closes on the modelled contour rather than on a cut edge, its base reaches the full 120° arc wherever the field still crosses the threshold there, and nothing is painted outside that arc. The beam's tilt is what puts the strongest part of a fan in a ring a hundred-odd metres out, under a 20 dB vertical floor, which is why a small clearing under a mast is the weakest place near it. Because the sector snapshot carries directions but not beamwidth, height, down-tilt or per-sector power, those remain assumptions, and they are labelled as such wherever they appear.

The path-loss model is selectable, and the default is Automatic: each mast is given one of the three profiles from how built up its surroundings are, counted as the number of other masts within 700 m — an isolated mast is read as open country, a sparse cluster as rural, a dense cluster as a town centre. That uses no dataset beyond the inventory itself, the panel reports how many masts each profile was chosen for, and because every profile attenuates at least as much as free space beyond the shared 25 m reference, the automatic field is never larger than the free-space one: the map keeps its worst-case reading and gains a shape that follows the country. Selecting Free-space baseline instead applies the least attenuating profile everywhere, which draws the largest fans and is the most conservative single-profile reading of the inventory.

All three profiles are calibrated at the same 25 m reference distance, which is the distance the rest of the model already uses for its nearest point. Each one therefore returns exactly the free-space value at 25 m and strictly less beyond it: rural sits below free space at every distance and urban below rural at every distance, with no crossover anywhere. Their fans are ordered the same way, so a per-site fan is never larger than the free-space baseline and never smaller than an urban one. (An earlier calibration measured each profile's clutter against a 1 km reference instead, which let the rural profile paint a larger fan than free space for weak masts — a contradiction that has since been removed.)

Where the antenna directions come from

The official BAKOM download used here is a site-level inventory: coordinates, operator, technology, power class, site type and installation limit value. Field by field it contains no antenna direction at all — no azimuth, no frequency, no sector identifier, no beamwidth, no down-tilt, no mast height and no per-sector power. That is why a map built from that file alone can only place points, however much detail it appears to show.

The azimuths this map draws come from a second public source: the sector geometry that public map services publish in their own vector tiles, decoded into a local snapshot. The register and that snapshot ship together as one file, data/antennas.json — nothing about this map is fetched from a third party at run time. Assembled from public sources; see Getting the underlying data below for what those are and the licences that apply. Horizontal beamwidth is not part of that format, so a 65° half-power panel is assumed, and a site with no matching record is drawn as an undirected disc rather than a guess at which way it faces. The width of the fan drawn here is a modelling choice and not a measured pattern: a sector is modelled across a 120° arc that fades to the standard −20 dB side-lobe floor at its edge, and is cut to nothing outside it.

That snapshot covers 96.9% of the official coordinates — 20,201 of 20,853, matched to a median of 10 m. The whole country is covered: the z8 tile block is fetched for every tile Switzerland touches, not just the ones a viewer had happened to load. The remaining 3.1% — 652 of the 20,853 coordinates — is not a geographic hole and not a zooming problem. 571 of those 652 are SBB's own railway installations and 579 of them are 2G-only, neither of which the reference dataset carries; asking its server for the same locations at a deeper zoom returns no new site, and the leftovers lie in the middle of the country rather than at any edge. Those installations are in the register with a coordinate and a power class — it is their direction the snapshot lacks. What keeps them off the map at all is a second and separate fact: every SBB installation is registered as 2G-only, and this map draws no 2G layer. See What is included, and what is not below.

That snapshot is development scaffolding. A permissioned BAKOM sector export can replace it without touching anything else, because the loader and the model accept either — the direction list is the only thing that changes.

Municipal boundaries and population

The municipality ranking uses the official swisstopo swissBOUNDARIES3D release — layer TLM_HOHEITSGEBIET, records of type Gemeindegebiet — giving 2,123 municipal boundaries with their official area and resident population. The boundaries are simplified to about 280 m, far finer than they are ever drawn at, and the tool that builds the file ships with the project.

Each municipality is sampled at up to 16 interior points on a uniform area grid, and the figure shown is the median of those samples. A mean over an area would be dominated by whichever sample happened to fall a few tens of metres from a mast, because the model falls off with the square of distance; the median is the typical point instead. It remains an area statistic rather than a per-resident one, which is why the population is shown next to it.

The centre of a municipality — the point its exposure-at-centre figure and its green disk are measured from — is the coordinate OpenStreetMap labels the settlement with (place=city|town|village|hamlet), ranked by place class and then by population, so a municipality holding a town and four hamlets is centred on the town. That is the built-up area by construction; the geometric centroid of a boundary is an area property and in many municipalities lands in fields while the village sits at an edge. 2,109 of the 2,123 municipalities take an OpenStreetMap settlement inside their boundary, 11 take the nearest one outside it, and 3 fall back to the centroid. The disks are drawn as a filled circle whose rim is the same one-pixel stroke the fan contours use, and a disk's radius is the distance from that centre to the nearest modelled contour — so a disk stops exactly where the closest fan begins, which is a claim you can check with a ruler against the map. Two things follow from what a disk is. Overlapping disks are filled as one union, so the shared ground takes the same tint rather than doubling it, and no rim is drawn across another disk's fill: that shared ground is not a boundary the model measured, and a line through it would read as one. Each rim therefore draws only the arcs that still stand against the open map.

The model is an upper bound

The field assumes every sector transmits its permitted maximum, continuously, in the direction of every point, from one assumed mast height, tilt and vertical beam for the whole country. Real networks transmit far less, almost never at the permitted maximum, and are blocked by buildings, terrain and vegetation. The map is therefore useful for comparing places, directions and technologies, and is not a prediction of the field strength at an address. Read it that way and it is informative; read it as a measurement and it will mislead you. As a yardstick for how far above reality it sits: the median settlement on this map reads about 0.2 V/m, against measured medians of 0.08–0.09 V/m and a highest-ever recorded value of 0.48 V/m in Switzerland.

What is included, and what is not

• Included: every registered mobile installation of the three Swiss operators and of other site owners, with power class, technology, coordinates and sector azimuths — 21,261 of the 22,482 register rows, this being every row that carries 5G, 4G or 3G.
• Not drawn — the 2G layer: the 1,221 2G-only installations in the register, of which 1,201 are operated by SBB, the railway base stations. This map models 5G, 4G and 3G, so a site registered as 2G-only is neither plotted nor summed: no dot, no fan, no popup, no figure. Its coordinates, power class and installation limit value are in the register and can be read above; what no bundled source carries for them is a direction, because the sector snapshot holds no 2G record at all.
• Not included: broadcast transmitters, high-voltage lines, radar, the railways' own dedicated radio network and other radio sources. They exist, they are regulated separately, and this build does not draw them.
• Not included: official measurement points. Cantonal and federal measurement programmes collect those, and they are the reference to compare against.

What the missing 2G layer means for a quiet reading. A 2G-only installation contributes to nothing on this map, so where the nearest mast is one of those 1,221 the figure shown is lower than the register allows. That matters most where a reader is looking for reassurance: a place drawn as empty is a place no modelled generation reaches, and if a 2G-only site stands there the accurate reading is "not modelled here" rather than "nothing here". What is missing is bounded and modest — 1,157 of the 1,201 SBB installations are registered in one of the two lowest power classes (≤6 W or ≤500 W), 44 in the medium class and none in the highest — and 2G is the oldest layer in the register, a voice service rather than a data one. Every figure on this map is a model output rather than a measurement, and a low one near a 2G-only site is no exception.

Getting the underlying data

This build is assembled from public sources, and those sources keep their own licences. The antenna register is open government data, published on map.geo.admin.ch and opendata.swiss; the federal installation limits and the measurement reports come from the same federal offices, and the cantonal environmental offices publish their own measurement programmes. The settlement points, place names, boundaries where OpenStreetMap supplies them and the basemap come from openstreetmap.org under the ODbL licence, which requires the attribution shown on the map and any reuse of that data to keep the same licence. The official municipal boundaries and population figures come from the swisstopo open-data release named above. The direction snapshot is decoded from publicly published map tiles.

Where the same ground is covered by other open collections — the crowdsourced OpenCelliD database at opencellid.org holds several hundred thousand Swiss cell records, and several cantons publish their own measurement programmes — this build still reads the federal register and the published tiles rather than those collections, and quotes them only where a page says it does. They are named here because a reader comparing this map with another source should know which of them share an origin and which do not. See International data for what an open, worldwide collection of that kind contains and what it does not.

If you want the numbers behind this map rather than the map itself, start with the federal mobile-antenna open-data layers, then compare what you find there with the cantonal and federal measurement reports.

Accessibility

The field is drawn on canvases that assistive technology cannot read, so nothing meaningful is only in the picture: the inventory count, the modelled peak, the selected threshold and the units are all written out in the panel, every control is a real form element with a label, the map itself is a keyboard-focusable region with a text label, and all text meets contrast requirements against the translucent panels. Fan opacity is user-controlled precisely because a fixed shading is not readable for everyone.

Found something wrong?

Model assumptions, dataset quirks and rendering behaviour are documented in the project README, including the known limits of the sector snapshot. Corrections are welcome — an exposure map is only as good as its willingness to be checked.

Estimates, not measurements

Everything this site draws is a model output. It is provided for information and research, without warranty of any kind, and it is not a measurement, not a compliance assessment and not medical, legal or property advice. Do not base a purchasing decision, a health decision or a regulatory dispute on these values without an independent measurement from a qualified service.

No warranty

The software and the data snapshot are provided "as is". Antenna inventories are updated quarterly by the federal authorities and the local snapshot may be older than that; sector azimuths come from a third-party derived snapshot whose coverage is partial, and panel beamwidth, the width of the arc each fan is drawn across, down-tilt and per-sector power are assumptions rather than values from the source data. Interruptions, inaccuracies and omissions are possible, and no liability is accepted for their consequences.

Third-party data and attribution

Base map tiles and their copyright belong to the OpenStreetMap contributors and are used under the Open Database Licence, with attribution shown on the map. Antenna inventory data is published by the Swiss Confederation through geo.admin.ch and opendata.swiss, and remains subject to the terms published with that data. Place and address search uses the Swiss federal geocoding service through api3.geo.admin.ch. Nothing on this page overrides those terms.

Your data

There is no account, no cookie, no analytics script and no server-side storage in this build. Searching sends only the text you type to the federal geocoding service so that it can return a place; "Locate me" asks your browser for your position and uses it only to centre the map, entirely inside the page. The antenna data, the fonts and the map library are all served from this same site rather than fetched from a content network or a font host, which leaves the basemap tiles — requested from OpenStreetMap's own servers, as they are by any map drawn on OpenStreetMap — as the only request the page makes while you are simply looking at it. Nothing about you is collected, profiled or shared, and nothing you type is retained.

Reuse

The map interface may be linked to, quoted and used freely for non-commercial information and research, with a link back to this site and the attributions above kept intact. Bulk redistribution of the antenna dataset should be taken from the official federal source rather than from this snapshot, so that recipients get the current version and the official terms.

Open questions and corrections

If a value on this map contradicts an official published source, the official source is the correct one. Reports of mismatches, rendering problems or accessibility barriers are genuinely useful and are the fastest way to improve the site.