The device that may summon nobody

Start with the finding that inverts the usual advice. Cospas-Sarsat publishes a table of national regulations for personal locator beacons, and for Switzerland it reads: "Terrestrial Alerts are relayed to Police. Appropriate SAR action cannot be guaranteed as no legislation and no formal responsibilities or procedures are available. A mobile telephone, emergency radio network access, emergency telephone or satellite telephone are more suitable for raising the alarm in an emergency for some circumstances." Austria carries near-identical wording — alerts relayed to "Police or Landeswarnzentrale" — as does Liechtenstein.

It goes further than "not guaranteed". PLB carriage is not permitted in Denmark, Korea (Rep. of), Myanmar and North Macedonia; Japan prohibits land activations "and subject to penalty by radio law"; Russia prohibits terrestrial use; and "Serial-coded PLBs are not allowed in Germany".

Two honesty notes. The page carries no date, so we cite it as published by Cospas-Sarsat, not "as of 2026" — check it before you fly. And Nepal appears nowhere in the table: that is not listed, which is neither permitted nor prohibited.

The practical reading: a beacon is superb for wilderness with a functioning national SAR pathway, and in the Alps the phone and the radio are what the system is built around.

Sources: Cospas-Sarsat — national beacon regulations for PLBs.

PMR446: licence-free, 500 mW, no repeaters

In Europe the walkie-talkie band is PMR446, and the rules are short. ECC Decision (15)05 requires CEPT administrations to exempt PMR446 equipment "from individual licensing", so "anyone can use the radio equipment without any prior individual permission". One sentence then carries the whole technical regime: "all PMR 446 equipment is hand portable and shall use only integral antenna and an effective radiated power not exceeding 500 mW, while any base station, repeater or fixed infrastructure use is excluded."

That limit is binding EU law, not guidance: Commission Implementing Decision (EU) 2025/105 lists band 83 as 446,0-446,2 MHz | PMR446 | 500 mW e.r.p. and states the equipment "shall not be used as a part of infrastructure network nor as a repeater". An integral antenna is legally one the user cannot disconnect "with the intent to connect another antenna", so the aftermarket whip is not a legal upgrade — and Swiss BAKOM is blunt: "PMR446 relays, gateways and fixed stations are not authorised."

National detail still matters across borders. Switzerland is licence-exempt at 0.5 W, France allows 500 mW p.a.r., and the UK adds a restriction of its own: "Airborne use is not permitted". Germany's current instrument is Vfg. 91/2025 — and the repealed Vfg 46/2020 PDF is still live on the regulator's own site, a trap for anyone citing the first search result.

A correction, because everyone repeats it: the claim that PMR446 has "16 analogue plus 16 digital channels" appears in no official source. The one official document enumerating every carrier is the Swiss interface requirement, from which there are 16 carriers on the 12.5 kHz raster and 32 on the 6.25 kHz raster — and the 16 "digital" 12.5 kHz channels are the same frequencies as the analogue ones, not a second set.

Sources: ECC/DEC/(15)05 (PDF); Commission Implementing Decision (EU) 2025/105; BAKOM — PMR446; OFCOM CH — RIR0507-35; Ofcom IR 2030 (UK Government Web Archive, snapshot 2 July 2024); BNetzA — Vfg. 91/2025 (PDF); ANFR — TNRBF 2026 (PDF).

FRS and GMRS: the American split

In the United States the same handheld hardware divides into two services. FRS needs no individual licence, has 22 channels of 12.5 kHz, and splits power by channel: ERP "on channels 8 through 14 does not exceed 0.5 Watts" and "on channels 1 through 7 and 15 through 22 does not exceed 2.0 Watts". As in Europe, "The antenna must be a non-removable integral part of the FRS transmitter type."

GMRS is the licensed tier, and the licence is easy: an individual at least 18 years old, a ten-year term, a USD 35 fee, and the licensee's "immediate family members" — a list running from spouse and children out to nieces, nephews and in-laws — may operate the station. What you buy is real capability: up to 50 W for mobile, repeater and base stations, with repeaters expressly provided for. That, not marketing, is why GMRS outperforms FRS and PMR446.

Two rules deserve to be better known. "Operators of GMRS stations must, at all times and on all channels, give priority to emergency communications." And a licensee "may allow anyone to operate his or her GMRS station if necessary to communicate an emergency message."

Sources: eCFR — 47 CFR Part 95, Subpart A; Subpart B (FRS); Subpart E (GMRS); eCFR — 47 CFR §1.1102.

Why the range on the box is fiction

The physics first. ITU-R Recommendation P.526 defines the condition: "As a practical rule, propagation is assumed to occur in line-of-sight (LoS)… if there is no obstacle within the first Fresnel ellipsoid." The ITU's own VHF/UHF coverage prediction method is likewise terrain-driven, based on "the terrain profile". A ridge between you and your partner is not attenuation; it is the end of the path.

Then the observation. The US National Weather Service, describing reception of its own weather-radio broadcasts, states that "Forests, deserts, and hills/mountains tend to greatly reduce reception", while "higher elevations will enhance the signal". Those are fixed, high-power broadcast transmitters. Your handheld is half a watt.

And the finding: across two research passes through the ECC decision, the EU implementing decision, Ofcom, BAKOM, BNetzA, the French TNRBF, the ITU and NOAA, no regulator or standards body publishes a range figure for a PMR446- or FRS-class handheld. So this article prints none. What regulators do publish is the opposite of a guarantee: BNetzA offers "keine Gewähr" for minimum quality or freedom from interference, France states "aucune garantie de protection", and the Swiss interface requirement grants the band a "non interference basis / non protection basis". The ECC even deflates the digital upgrade: its benefit is "Improved quality of service extending out to the range limit (rather than greater absolute range)".

Treat the kilometre figure on the packaging as marketing, and plan the day as if the radio works only within sight.

Sources: ITU-R P.526-16 (PDF); ITU-R P.1812; NWS — NOAA Weather Radio reception; ECC/DEC/(15)05 (PDF); BNetzA — Vfg. 91/2025 (PDF); ANFR — TNRBF 2026 (PDF).

The one radio channel that answers: 161.300 MHz

Switzerland runs something no other Alpine country in this dossier matches. Rega: "The emergency radio channel (161.300 MHz) can be used by anyone throughout Switzerland to call out the rescue services in the event of an emergency if this is not possible by telephone… The emergency radio channel is monitored by Rega's Operations Center." It rides a national network of 46 stations, and a 123.0 Hz tone squelch is needed to reach local rescue services in Haute-Savoie and the Aosta Valley.

Rega also states the limits, which is why we trust the rest: "While coverage is considerable, there are some areas where radio contact cannot be established. Consequently, Rega's emergency channel cannot be used to raise the alarm from every single location in Switzerland."

This is also what Cospas-Sarsat means when it tells Swiss users to prefer "emergency radio network access".

Sources: Rega — emergency radio; Rega — this is how we help you.

Beacon or messenger: the hop that separates them

Outside the jurisdictions above, a 406 MHz PLB has one decisive property. NOAA: "A 406 beacon is the only emergency signaling device that puts your distress situation directly in the hands of the national SAR network. 406 beacons have worldwide coverage." No subscription is involved; registration is "required, is free of charge".

A satellite messenger works differently, and Rega documents the difference precisely: an SOS from a satellite communicator "will be transmitted to an international emergency call centre. This call centre then alerts the rescue services responsible for the region." A commercial relay sits in the middle. Garmin's inReach also requires an active subscription for SOS, and Garmin states that the subscription "does not include additional insurance coverage or cover any possible costs incurred from an emergency response".

Two more facts worth carrying. Satellites stopped listening to the old frequency long ago — "121.5/243 MHz processing by Cospas-Sarsat ceased on 1 February 2009" — and it survives only as a low-power signal "as a reference for local search teams to 'home' in on". And beacons are type-approved to −40 °C (Class 1) or −20 °C (Class 2), while Apple specifies iPhones "for use where the ambient temperature is between 0º and 35º C" — a manufacturer figure, but the direction is not in doubt.

Sources: NOAA SARSAT — plan your adventure; NOAA SARSAT — FAQs; Rega — this is how we help you; Garmin — Interactive SOS; Cospas-Sarsat — detailed system description; Cospas-Sarsat — selecting a beacon model; Apple — operating temperature.

Registration: the step people skip

Register your beacon "with the national authority associated with the country code in the hexadecimal identification (15 Hex ID) of your beacon" — not where you live, not where you are walking. NOAA refuses foreign-coded beacons: "Beacons must be registered in the country for which they are coded." Confirm the details every two years; registrations untouched for ten years are removed.

A home-registered beacon still works abroad, because alerts are dual-routed: the Mission Control Centre sends them to the SAR authority "in the area where the beacon is believed to be" and to the government associated with the beacon's country code.

Verified registries: the USA (required and free), the UK — "You must register your beacon and keep your registration up to date", free, about 15 minutes, though the page cites no statutory instrument, no renewal period and no penalty, so we assert none — Australia, free and "in some cases it is mandatory by law", and New Zealand, where DOC states registration is required by law.

On skipping it, the two authorities differ in tone and we print both. AMSA is unhedged: "An unregistered beacon can delay the response." Cospas-Sarsat is softer: "The System will still work but not registering your beacon defeats the purpose of owning a beacon." Nothing official says an unregistered beacon is ignored.

Sources: Cospas-Sarsat — beacon registration FAQ; Cospas-Sarsat — what happens when I activate my beacon; NOAA — beacon registration database; NOAA RGDB — FAQ; GOV.UK — register a 406 MHz beacon; AMSA — beacon registration; DOC NZ — distress beacon.

The phone: better than you think, and not a plan

Two things work in your favour. An emergency call can go out "via any reachable mobile network" with the handset in a limited-service state — a network-layer behaviour, and what makes Austria's trick work: with no signal from your own network, restart the phone and dial 112 without entering the SIM PIN. And Advanced Mobile Location sends your handset's own position to the emergency centre "without the knowledge or involvement of the caller", closing an enormous accuracy gap: network-based location "may vary from 50 m to 40,000 m", handset-derived is accurate "up to 5 m".

Now the parts nobody flags. Even where a national emergency centre is upgraded to receive AML, "a significant number of calls do not benefit from this very accurate location (up to 60% of calls)"; only 8 Member States confirmed handset-derived location for roaming users, and "by default AML does not operate properly for roaming callers" — which is most trekkers in the Alps. Worse, the SIM-less or limited-service handset that gets your call through is "incapable of originating SMS due to a lack of proper network registration". The trick that connects the call can cost you the automatic position — so read your coordinates out loud instead. Where there is no coverage at all and open sky, iPhone satellite SOS is the other fallback: Apple's terms say free for two years after activation, the free period has been extended repeatedly and no post-free price has ever been announced, so the honest word is currently free.

And then the chorus from the agencies that run the rescues. NOAA: "mobile phones do not work in most truly wilderness locations." NPS: "Your cell phone is not a substitute for any of the 10 essentials." NZ MSC, on satellite-to-phone SOS specifically: "we do not recommend you rely solely on your mobile phone as an emergency communication device", because dense bush or a narrow valley can take away your line of sight to the sky. Mountaineering Scotland gives the reason a beacon differs: it does "not rely on being within 'line of sight' to a mobile phone transmitter" — while Rega notes that mast-based positioning in the mountains "sometimes… can deviate by several dozen kilometres".

If everything electronic fails, the alpine distress signal still works: a visible or audible signal six times a minute, one minute's pause, repeat.

Sources: ComReg 23/117 (PDF); European Commission — COM(2024) 575; Bergrettung Österreich — Notruf absetzen; Apple — Emergency SOS via satellite; NOAA SARSAT — plan your adventure; NPS — trip planning guide; NZ MSC — communications; Mountaineering Scotland — calling for help; Rega — this is how we help you; Bergrettung Salzburg — Alpines Notfallsignal.

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