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What is the limit of a transmitter in the GSM1800 band (~1830 MHz)?

The ETSI GSM specification states a limit of -47dBm between 1GHz and 12.75GHz (https://www.etsi.org/deliver/etsi_gts/05/0505/05.00.00_60/gsmts_0505v050000p.pdf).

However, to my understanding these are spurious emissions from the transmitter itself.

I am wondering about a non-GSM transmitter leaking into the GSM1800 and whether these limits can be derived from the above document in the first place.

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I am wondering about a non-GSM transmitter leaking into the GSM1800 and whether these limits can be derived from the above document in the first place.

They can't. This is subject to local laws, not communication standards – and usually formulated and enforced by the regulatory body of a country (FCC in the US, OFCOM in UK, BNetzA in Germany, MIC in Japan, …) with laws governing the guidelines for that regulation.

As a general "rule of why things are legislated": These laws exist to protect services (in your case, cellular telephony and data transfer) from interference from other services and unintentional radiators.

Thus, it's realistic to assume that local laws are written so that the interference levels do not mitigate normal operation even in the low signal strength regimes of the protected services.

GSM handsets need to work down to -120 dBm per standard. That kind of implies that you might get into trouble if your out-of-band radiation is significantly more that; the definition of "significantly" will heavily vary between countries.

In other words, if you can measure it when using the smallest resolution bandwidth of your spectrum analyzer, chaaaaaances are it's too much. Again, for more information, you'll need to refer to your local regulator.

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  • $\begingroup$ Hi Marcus, while I agree with everything you said but you basically repeated my question. I am aware that there is a standard and regulators (FCC/ETSI/...). Per my question, the local regulator is ETSI (Europe) and I would be curious about which level of spurious emissions are allowed in this band. Your assessment of -120dBm already helps a lot, though. $\endgroup$ – divB Nov 15 '19 at 19:33
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    $\begingroup$ ETSI is not your regulator. ETSI is the standardization organization. (Nearly) every European country has their own regulator. $\endgroup$ – Marcus Müller Nov 15 '19 at 19:42

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