The ITU, the Regions and Article 25

Section B of the ASOC paper is called Radio Regulations, and half of it is not Indian at all. It is the ITU Radio Regulations — the treaty text that decides which services may use which slice of spectrum anywhere on earth, what an amateur station is allowed to be, and what your call sign may look like. Indian law sits on top of that text rather than beside it, so once you understand the ITU framework the Indian rules stop being a list to memorise and become consequences. This lesson covers Articles 2, 5 and 25.

What the ITU is

The International Telecommunication Union is a specialised agency of the United Nations, based in Geneva, responsible for international telecommunication. It is not an Indian body, not a manufacturers’ association, and not a club of radio amateurs. Its members are sovereign states — India among them — and its radiocommunication sector, ITU-R, is the part that concerns you.

The worldwide federation of national amateur radio societies is the IARU, the International Amateur Radio Union. It is a sector member of the ITU and speaks for amateurs at ITU conferences, but it is not the ITU. The examiner offers that confusion as a distractor.

The Radio Regulations are a treaty

The ITU has a Constitution and a Convention, and annexed to them are the Radio Regulations. By that annexation the Regulations carry treaty force: not guidance, not a recommended practice, not a voluntary standard, but binding in international law on every member state that has signed.

A treaty does not by itself put a person before an Indian court, so India gives the Radio Regulations domestic effect through its own law. The Telecommunications (Amateur Services) Rules, 2024 — G.S.R. 675(E) of 29 October 2024, made under the Telecommunications Act, 2023 — replaced the Indian Wireless Telegraphs (Amateur Service) Rules, 1978. Old and new work the same way: they authorise a station, then make that authorisation subject to the relevant provisions of the Radio Regulations. The 1978 Rules went further and defined “Convention” to include the Radio Regulations annexed to it, so that breaching an ITU provision directly breached your Indian licence. That is why Section B examines both together. See the Indian rules for the national half.

The three ITU Regions

Spectrum is not allocated identically worldwide: Europe wanted different broadcasting arrangements from North America, and Asia had different existing users again. Article 5 therefore divides the world into three Regions — separated by Line A, Line B and Line C — and gives the Table of Frequency Allocations a column for each.

The lines are defined by meridians and parallels, not by coastlines. Line A runs from the North Pole down the meridian 40° E to the parallel 40° N, then by great circle arc to where 60° E crosses the Tropic of Cancer, then down 60° E to the South Pole. India lies well east of that, so India is in ITU Region 3 — the first thing to check before believing a band plan printed in an American magazine. India is also in ITU Zone 41 and CQ Zone 22, two other zone systems used for propagation prediction and contest scoring, and neither of them a Region.

Article 5 — allocation, and the meaning of “secondary”

Article 5 contains the Table of Frequency Allocations: for every band, in each Region, the services entitled to use it. A primary service is printed in capitals, has full rights in the band and is protected from interference; a secondary service is printed in ordinary type and takes what is left over. Secondary status places two obligations on you and grants you one thing:

1. You shall not cause harmful interference to stations of a primary service — whether those stations were there before you or were assigned their frequencies later.
2. You cannot claim protection from harmful interference caused to you by stations of a primary service.
3. You can claim protection from harmful interference caused by stations of the same or another secondary service assigned frequencies later than yours.

In practice: if a primary user appears on your secondary allocation, you stop, retune or reduce power. You do not argue and you do not ask them to move. India’s 30 m (10100–10150 kHz), 6 m and 70 cm (434–438 MHz) allocations are held on exactly this footing, and 17 m and 12 m are authorised on a non-interference, non-protection basis — the same idea in the licence’s own words. The Indian band, power and emission table marks each one.

Article 2 — the nomenclature of frequency and wavelength bands

One rule generates the entire band table, and the examiner tests the rule as often as the table:

Put N = 7 and you get 0.3 × 10⁷ = 3 MHz up to 3 × 10⁷ = 30 MHz, which is HF; N = 8 gives 30 to 300 MHz, VHF. Every band is one decade wide. The note to the table adds the boundary rule, worth a mark on its own: the lower limit is excluded and the upper limit is included. HF is therefore “above 3 MHz, up to and including 30 MHz”, and a signal on exactly 30.000 MHz is the last HF frequency, not the first VHF one.

The prefix B. means “band of ... -metric waves”, and the Radio Regulations table begins at band 4.

The metric names are not arbitrary. They come from the wavelength, which comes from the frequency:

HF runs 3 to 30 MHz, so its wavelengths run 100 m down to 10 m — tens of metres, hence decametric. VHF gives 10 to 1 m, plain metric; UHF 1 m to 0.1 m, decimetric; MF 1000 to 100 m, hectometric; LF 10 000 to 1000 m, kilometric; VLF 100 000 to 10 000 m, myriametric. Learn the reasoning once and you never need the column again.

How the Regulations express a frequency

Article 2 also fixes the units, so that no frequency in the Regulations needs more than four significant figures:

• kilohertz up to and including 3 000 kHz;
• megahertz above 3 000 kHz, up to and including 3 000 MHz;
• gigahertz above 3 000 MHz, up to and including 3 000 GHz.

That is why the Indian licence writes 40 m as 7000–7200 kHz and 2 m as 144–146 MHz, and why “7.2 MHz” never appears in a regulatory table.

Practise the naming until it is automatic

Type any frequency into the box below and it gives you the wavelength, the ITU band with its number and metric subdivision, and whether a Restricted licensee may transmit there. Do the two worked examples in your head first, then check them here.

Worked example 1 — a frequency you will actually use

You are calling on 14.200 MHz. Name the band.

λ = 300 ÷ 14.2 = 21.1 m — tens of metres, so decametric. 14.2 MHz is above 3 MHz and at or below 30 MHz, so it is band 7, HF, decametric waves, and a primary Indian allocation at up to 50 W DC input for a VU3.

Worked example 2 — the other end of your licence

Your handheld is on 435.000 MHz. Name the band.

λ = 300 ÷ 435 = 0.69 m — a fraction of a metre, so decimetric. That is band 9, UHF, decimetric waves, and the 70 cm allocation is secondary: if a primary user turns up, you go.

Article 25 — the amateur service

Article 25 is the article that says what you are.

International contacts

No. 25.1 permits radiocommunication between amateur stations of different countries by default. The only bar is that an administration may notify that it objects, in which case its amateurs are off limits. The Indian licence conditions repeat this.

What you may talk about

No. 25.2 limits transmissions between amateur stations of different countries to communications incidental to the purposes of the amateur service, as defined in No. 1.56, and to remarks of a personal character. Both limbs matter: purely technical traffic is not the ceiling — family, weather and work are expressly allowed. What is excluded is business, news, advertising, broadcasting and anything done for reward.

No. 25.2A forbids encoding for the purpose of obscuring meaning, the one exception being control signalling between earth command stations and satellites in the amateur-satellite service. Q-codes, standard abbreviations and published digital modes such as RTTY or FT8 are not caught: their meaning is public, and anyone with the same software can read them. A private cipher agreed with one friend is caught, however trivial.

Third-party traffic

No. 25.3 is the one most often got wrong. Amateur stations may transmit international communications on behalf of third parties only in case of emergencies or disaster relief, and each administration may decide whether even that applies to its own amateurs.

Proving you can operate

The Regulations once required every amateur wanting to work below 30 MHz to have proved the ability to send correctly by hand, and to receive correctly by ear, texts in Morse code signals. That was No. 25.4, suppressed at WRC-03. It is gone from the treaty. What remains is a pair of provisions:

• No. 25.5 — administrations shall determine whether or not a person seeking a licence shall demonstrate the ability to send and receive texts in Morse code signals. The decision belongs to each country.
• No. 25.6 — administrations shall verify the operational and technical qualifications of any person wishing to operate an amateur station. Guidance on the standard of competence is in Recommendation ITU-R M.1544.

India has exercised the No. 25.5 discretion by requiring no Morse at all for the Restricted grade, and 8 words per minute sending and receiving for the General grade; the No. 25.6 verification is the ASOC examination itself. If a practice paper tells you that every amateur must pass a Morse test, it is quoting a provision that has not existed since 2003.

The rest of Article 25

Section II — the amateur-satellite service

No. 25.10 applies the whole of Section I to the amateur-satellite service, as appropriate: same purposes, same content limits, same identification duty. No. 25.11 adds one requirement of its own — an administration authorising an amateur space station must ensure that sufficient earth command stations are established before launch, so that any harmful interference the satellite causes can be terminated immediately. That is why No. 25.2A carves out command signalling from the encoding ban: a command link anyone could forge would be worse than no command link.

In India the amateur-satellite service is authorised to General grade licensees only, at a maximum of 30 dBW e.i.r.p. A VU3 may listen to satellites all day, and should — but may not transmit through one.