The same model number is a different radio in three markets

Radio spectrum is a national asset. Each country's regulator licenses slices of it to operators, and those slices are not the same slices in the next country. The industry names them: band 20, band 28, n78. A phone's modem supports a specific list, and the list is a hardware and certification decision made per market before the phone is boxed.

This is why an imported phone can be entirely functional and still perform worse than the local model of the same name. Nothing is locked. It simply does not transmit or listen on a frequency the local network is using.

Which bands matter, and why the low ones matter most

Low frequencies travel further and pass through walls better; high frequencies carry more data over shorter distances. That trade is physics, not policy, and it decides what a missing band costs you.

Miss a high band and you lose capacity in a crowded place, which shows up as a slow connection in a stadium. Miss a low band, which is what operators use for rural coverage and for reaching indoors, and you lose service altogether in places the local model works. The second failure is the one that makes an imported phone feel broken, and it is invisible in a city centre where the test usually happens.

5G splits along the same line. Sub-6 is where coverage is: below about 6 GHz, behaving much like 4G in reach. mmWave, above about 24 GHz, delivers very high throughput over a street's width and is stopped by a wall or by heavy rain, which is why it exists in dense venues and along a few corridors rather than as national coverage. A phone sold with mmWave hardware in one market and without it in another is usually reflecting that, not withholding a feature.

What else makes a market variant

Bands are the substantial difference, but not the only one. Regulators set different limits on radiated power, on which Wi-Fi channels may be used, and in some markets on whether a phone must carry a physical SIM tray at all. Chinese models often ship without the Google services layer, which is a software difference rather than a radio one but travels under the same "regional variant" heading.

Each variant also needs its own certification, which costs money per market. That is the commercial reason band lists are trimmed rather than universal: supporting a band nobody near the buyer uses adds filters, antenna tuning and paperwork to every unit.

How to check before buying

The model number is the key, not the marketing name. A maker's own specification pages list supported bands per model number, and the regulatory database of the market you are buying into records what was certified there. Compare the list against the bands your own operator publishes, and pay more attention to the low-frequency entries than to the count.

Band support is fixed in hardware and cannot be added later by an update. It is one of the few phone specifications that is genuinely permanent, which is worth remembering next to a chip whose real performance depends on the phone around it.

Sources

1. 3GPP, TS 38.101-1, NR user equipment radio transmission and reception, band definitions, read 17 September 2026
2. ITU Radiocommunication Sector, Radio Regulations on national spectrum allocation, read 17 September 2026
3. GSMA, spectrum policy position on low-band coverage and high-band capacity, read 17 September 2026