What is the difference between licensed and license-free spectrum?

Licensed spectrum is assigned to a named holder who gets an individual right of use. License-exempt spectrum is open to any device that meets published technical conditions, without an individual permit. In the EU, Decision 2006/771/EC makes short-range device bands available on a non-exclusive, non-interference and non-protected basis: a device may cause no harmful interference to radiocommunication services and may claim no protection from them.

What is the difference between EIRP and ERP?

EIRP (e.i.r.p.) is referenced to an isotropic antenna, ERP (e.r.p.) to a half-wave dipole, which has a gain of about 2.15 dBi. The same emission therefore reads about 2.15 dB higher in EIRP than in ERP. The EU texts state sub-GHz SRD limits in e.r.p. (for example 25 mW e.r.p. at 868 to 868.6 MHz) and limits above 1 GHz in e.i.r.p. (for example 100 mW e.i.r.p. for wideband data at 2.4 GHz). The FCC states 15.247 and 15.407 limits mostly as conducted power with a 6 dBi antenna allowance, and 15.249 limits as field strength at 3 metres.

Which ETSI standard applies to my band?

As cited under Implementing Decision (EU) 2022/2191 as amended: EN 300 220-2 (V3.1.1 or V3.3.1) for non-specific SRD from 25 MHz to 1 000 MHz, EN 300 328 V2.2.2 for wideband data at 2.4 GHz, EN 301 893 (V2.1.1 or V2.2.1) for 5 GHz WAS/RLAN. A 2.4 GHz non-specific SRD at 10 mW e.i.r.p. falls under EN 300 440, not EN 300 328, and SRD in data networks at 865 to 868 and 915 to 919.4 MHz under EN 303 659. Check the exact version against the current consolidated list.

Is 868 MHz European and 915 MHz American, with no overlap?

Not any more. 863 to 870 MHz has no US Part 15 equivalent, but the EU does harmonise part of the 915 MHz range. Implementing Decision (EU) 2018/1538, as amended by (EU) 2025/650, makes 916.1 to 919.4 MHz available for short-range devices in data networks (25 mW e.r.p., duty cycle 1 % or less, implementation deadline 1 October 2025) plus RFID and 500 mW network entries. Member States may opt out where the band is used for defence, and the US band runs 902 to 928 MHz with very different power rules, so a dual-market product still needs two configurations and two test campaigns.

What is duty cycle and why does it limit my throughput?

Decision 2006/771/EC defines duty cycle as the ratio, in percent, of the cumulated on-time of one transmitter over the observation period, which is one continuous hour unless the annex says otherwise. A 1 % limit means 36 seconds per hour, 0.1 % means 3.6 seconds. In most 863 to 870 MHz bands a device may instead use spectrum access and mitigation techniques of at least the performance described in the harmonised standard (listen before talk with adaptive frequency agility in ERC Recommendation 70-03, polite spectrum access in EN 300 220-2).

What are DFS and TPC in the 5 GHz band?

DFS (Dynamic Frequency Selection) detects radar and moves off the channel, TPC (Transmit Power Control) reduces power. In the EU, Implementing Decision (EU) 2022/179 requires both at 5 250 to 5 350 MHz and 5 470 to 5 725 MHz, not at 5 150 to 5 250 MHz, and equipment without TPC must cut its e.i.r.p. limit by 3 dB. EN 301 893 sets a 60 s channel availability check (10 minutes at 5 600 to 5 650 MHz), a 10 s channel move time and a 30 minute non-occupancy period. In the US, 47 CFR 15.407(h) requires DFS in the same two sub-bands (60 s check, 10 s move, 30 minutes non-occupancy), and TPC only for systems at 500 mW e.i.r.p. or more.

Does a certified radio module let me skip band compliance?

Not entirely. Under the RED the manufacturer of the final product assesses it in all possible configurations (Article 17(1)), so antenna gain, placement and firmware settings that change radiated power or channel access are back in scope. Under FCC rules, a module grant can be reused only within its grant conditions, and any intentional radiator under Part 15 needs certification by a TCB (47 CFR 15.201(b)).

Radio spectrum: SRD and license-free bands

Hugues Orgitelloupdated 7 Oct 202617 min read

Before a wireless product can exist, it must answer one question: can I legally transmit on this frequency, at this power, in this region? Most consumer and industrial radios never touch licensed spectrum. They live in license-exempt short-range device (SRD) bands, where access is open to anyone who respects a published rulebook. In the EU that rulebook is binding law, Commission Decision 2006/771/EC, last amended by Implementing Decision (EU) 2025/105 of 22 January 2025, plus separate decisions for 915 MHz and 5 GHz. In the US it is 47 CFR Part 15. This page reads the parameters straight from those texts, lists the harmonised standards cited as of October 2026, and corrects the readings that circulate most. It is the orientation layer under the RED pillar.

Licensed versus license-exempt spectrum

Licensed spectrum is assigned to a named holder with an individual right of use. Cellular operators, broadcasters and many satellite services work there, and a device transmits only under the holder's rights.

License-exempt spectrum is open to any equipment that meets published technical conditions. Article 3(1) of Decision 2006/771/EC obliges Member States to make the SRD bands available "on a non-exclusive, non-interference and non-protected basis", and Article 2 defines that basis: no harmful interference may be caused to any radiocommunication service, and no protection may be claimed from it. ERC Recommendation 70-03 adds that SRD applications are not a radiocommunication service within the meaning of Article 1 of the ITU Radio Regulations.

The practical consequence: in licensed bands you negotiate access; in license-exempt bands you earn access by conformity, and you accept the interference that comes with sharing.

Which text binds, and which one guides

Three EU-level documents get mixed up. They do not have the same legal weight.

Document	Nature	What it covers	Latest change
Decision 2006/771/EC	Binding on Member States ("shall designate and make available")	SRD bands from 9 kHz to 246 GHz, by category	Implementing Decision (EU) 2025/105 of 22 January 2025; consolidated text of 23 January 2025
Implementing Decision (EU) 2018/1538	Binding on Member States, with an opt-out where the band serves defence or public security	874 to 876 MHz and 915 to 921 MHz, SRD in data networks and RFID	Implementing Decision (EU) 2025/650 of 26 March 2025, new entries due by 1 October 2025
Implementing Decision (EU) 2022/179	Binding on Member States, bands due by 31 March 2022	5 GHz WAS/RLAN (5 150 to 5 350 and 5 470 to 5 725 MHz)	Amended by (EU) 2022/2307; repealed Decision 2005/513/EC
ERC Recommendation 70-03	CEPT recommendation, not EU law	All CEPT countries, with national deviations in Appendices 1 and 2	Edition of June 2026 (amended 5 June 2026)

ERC Recommendation 70-03 itself says that its technical parameters "may differ from those in the Commission Implementing Decision", for example because of different update cycles, and that its references to ETSI standards "are for information only". It remains the best map of what CEPT countries outside the EU accept, and of national restrictions. For an EU product, start from the decisions.

Decision 2006/771/EC also lets Member States go further: under Article 3(3) they may allow less restrictive conditions (more power, a higher duty cycle) as long as the harmonised sharing environment is not compromised. They may not add parameters beyond those in its Table 2.

The EU sub-GHz bands, row by row

The rows below are copied from Table 2 of the consolidated Decision 2006/771/EC (23 January 2025). "Access techniques" means the annex note requiring spectrum access and mitigation techniques at least equivalent to those described in the harmonised standard.

Band No	Range	Category	Limit	Access or duty cycle	Implementation deadline
44a	433.05 to 434.79 MHz	Non-specific SRD	1 mW e.r.p.	none	1 July 2025
44b	433.05 to 434.79 MHz	Non-specific SRD	10 mW e.r.p.	duty cycle 10 % or less	1 January 2020
45c	434.04 to 434.79 MHz	Non-specific SRD	10 mW e.r.p.	up to 100 % if bandwidth 25 kHz or less	1 July 2025
87	862 to 863 MHz	Non-specific SRD	25 mW e.r.p.	duty cycle 0.1 % or less, bandwidth 350 kHz or less	1 January 2020
46a	863 to 865 MHz	Non-specific SRD	25 mW e.r.p.	access techniques, or duty cycle 0.1 % or less	1 January 2018
84	863 to 868 MHz	Wideband data transmission	25 mW e.r.p.	access techniques, bandwidth above 600 kHz up to 1 MHz, duty cycle 10 % (network access points) or 2.8 %	1 January 2018
47	865 to 868 MHz	Non-specific SRD	25 mW e.r.p.	access techniques, or duty cycle 1 % or less	1 January 2020
47b	865 to 868 MHz	Non-specific SRD (data networks only)	500 mW e.r.p. in four 200 kHz channels, APC required	duty cycle 10 % (network access points) or 2.5 %	1 January 2018
48	868 to 868.6 MHz	Non-specific SRD	25 mW e.r.p.	access techniques, or duty cycle 1 % or less	1 January 2020
50	868.7 to 869.2 MHz	Non-specific SRD	25 mW e.r.p.	access techniques, or duty cycle 0.1 % or less	1 January 2020
54	869.4 to 869.65 MHz	Non-specific SRD	500 mW e.r.p.	access techniques, or duty cycle 10 % or less	1 January 2020
56a	869.7 to 870 MHz	Non-specific SRD	5 mW e.r.p.	none	1 July 2025
56b	869.7 to 870 MHz	Non-specific SRD	25 mW e.r.p.	access techniques, or duty cycle 1 % or less	1 January 2020

The gaps at 868.6 to 868.7, 869.2 to 869.4 and 869.65 to 869.7 MHz are reserved for alarm devices (bands 49 to 55), with their own limits.

What the 2025 update changed. Implementing Decision (EU) 2025/105 replaced the annex, added the rows carrying a 1 July 2025 deadline (among them 44a, 45c and 56a, the alarm bands 49, 52, 53 and 55, and assistive listening and audio PMSE entries), added Article 3(2a) on at least 30 MHz of extra spectrum for audio PMSE, moved the Member State reporting date to 1 November 2025 and repealed Implementing Decision 2014/641/EU on audio PMSE.

Duty cycle, defined. The annex defines duty cycle as the ratio, in percent, of the summed on-time of a single transmitter to the observation period, which is a continuous one hour period unless stated otherwise. ERC Recommendation 70-03, Appendix 4, turns the classes into seconds: 0.1 % is 3.6 seconds per hour (shown there as five transmissions of 0.72 seconds), 1 % is 36 seconds, 10 % is 360 seconds.

868 MHz is not an ISM band. ERC Recommendation 70-03 lists the Annex 1 bands that are also ISM bands under the ITU Radio Regulations: 433.05 to 434.79 MHz, 2 400 to 2 483.5 MHz and 5 725 to 5 875 MHz are in the list, 863 to 870 MHz is not. In Europe 868 MHz is an SRD designation, nothing more.

The 915 MHz overlap that most guides miss

The US band runs from 902 to 928 MHz. The EU harmonised none of it until Implementing Decision (EU) 2018/1538, and Implementing Decision (EU) 2025/650 widened the entries. The current table reads:

Band No	Range	Category	Limit	Conditions	Deadline
1	874 to 874.4 MHz	Non-specific SRD, data networks	500 mW e.r.p., APC	bandwidth 200 kHz or less, duty cycle 10 % (network access points) or 2.5 %	1 July 2022
2	916.4 to 919.4 MHz	Wideband data transmission, data networks	25 mW e.r.p.	bandwidth above 600 kHz up to 1 MHz, duty cycle 10 % or 2.8 %	1 October 2025
3	916.1 to 918.9 MHz	RFID	4 W e.r.p. interrogators at 916.3, 917.5 and 918.7 MHz only	bandwidth 400 kHz or less	1 July 2022
4	917.3 to 918.9 MHz	Non-specific SRD, data networks	500 mW e.r.p., APC, only within 917.3 to 917.7 and 918.5 to 918.9 MHz	bandwidth 200 kHz or less, duty cycle 10 % or 2.5 %	1 July 2022
5	916.1 to 919.4 MHz	Non-specific SRD, data networks	25 mW e.r.p.	bandwidth 600 kHz or less, duty cycle 1 % or less	1 October 2025

Every entry is limited to data networks in which all nomadic and mobile devices are controlled by a master network access point, and note 6 lets a Member State skip an entry partly or entirely where the range serves public order, public security or defence and coordination is not possible. ERC Recommendation 70-03 carries a wider CEPT entry (Annex 1, band h3, 915 to 919.4 MHz, 25 mW e.r.p., duty cycle 1 % or less, 600 kHz) and notes that some countries use 918 to 921 MHz as extended GSM-R. The overlap with the US band is real, but narrow, conditional and nothing like the US power level.

The key parameters

EIRP versus ERP

EIRP (e.i.r.p.) is referenced to an isotropic radiator. Decision (EU) 2022/179 defines it as "the product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna".
ERP (e.r.p.) is referenced to a half-wave dipole, which has about 2.15 dBi of gain, so the same emission reads about 2.15 dB higher in EIRP than in ERP.

The EU texts use e.r.p. for the sub-GHz SRD bands and e.i.r.p. above 1 GHz. The US texts mostly limit conducted power and then penalise antenna gain: 47 CFR 15.247(b)(4) and 15.407(a) assume a directional gain of 6 dBi or less and reduce the allowed power by the excess. 15.249 and 15.231 use a third reference, field strength at 3 metres. Comparing an EU and a US limit therefore needs a conversion, not a glance.

Power: same band, different orders of magnitude

Band	EU limit (text)	US limit (text)
863 to 870 MHz / 902 to 928 MHz	25 mW e.r.p. in most sub-bands, 500 mW e.r.p. at 869.4 to 869.65 MHz (Decision 2006/771/EC)	1 W peak conducted for digital modulation or hopping on 50 channels or more, 0.25 W for 25 to 49 channels, with a 6 dBi antenna allowance (15.247(b)); or 50 mV/m at 3 m for any modulation (15.249(a))
2 400 to 2 483.5 MHz	10 mW e.i.r.p. non-specific SRD (band 57a); 100 mW e.i.r.p. wideband data, with 100 mW/100 kHz for hopping and 10 mW/MHz for other modulations (band 57c)	1 W conducted for digital modulation and for hopping on 75 channels or more, 0.125 W for other hopping systems (15.247(b)); or 50 mV/m at 3 m (15.249(a))
5 725 to 5 875 MHz	25 mW e.i.r.p. non-specific SRD (band 61)	1 W conducted at 5 725 to 5 850 MHz (15.247(b)(3) and 15.407(a)(3)(i))

Two consequences for design. First, a product sized for the US 1 W conducted allowance has to be re-tuned, not just re-labelled, for Europe. Second, the "digital modulation" route of 15.247(a)(2) requires a 6 dB bandwidth of at least 500 kHz: a narrower signal must hop (at least 50 channels at 902 to 928 MHz if the 20 dB bandwidth is under 250 kHz, with 0.4 s maximum dwell in 20 s), use the hybrid rules of 15.247(f), or fall back to the much lower field-strength limit of 15.249.

Channel access: duty cycle or polite access

Most EU sub-GHz entries give a choice: respect the duty cycle, or implement access and mitigation techniques at least as effective as those in the harmonised standard. ERC Recommendation 70-03 names the technique LBT with adaptive frequency agility (AFA); EN 300 220 Part 2 V3.3.1 calls it "polite spectrum access" and tests its timing. At 2.4 GHz, EN 300 328 V2.2.2 splits equipment into adaptive (with a sharing mechanism) and non-adaptive, the latter capped at a medium utilisation factor of 10 % for non-hopping equipment. The US rules have no general duty-cycle cap at 902 to 928 or 2 400 MHz; they constrain hopping dwell time instead. 15.231 is the exception, with periodic-operation limits (release within 5 seconds, polling no more than two seconds per hour).

Occupied bandwidth and spectral mask

Bandwidth caps appear directly in the EU tables (25 kHz, 200 kHz, 350 kHz, 600 kHz, 1 MHz depending on the row) and as minimums or maximums in 15.247 (500 kHz minimum for digital modulation, 500 kHz maximum per hop at 902 to 928 MHz). Out-of-band limits follow: 15.247(d) requires 20 dB below the in-band peak in any 100 kHz outside the band (30 dB when power is measured as an average), and restricted bands must meet 15.209. These measurements fail first-pass campaigns often enough to deserve attention at schematic stage.

The 5 GHz special case: DFS and TPC

The 5 GHz RLAN band shares spectrum with radar, Earth exploration satellites and other services. Two mitigation techniques protect them: DFS (Dynamic Frequency Selection) detects radar and moves the device off the channel, TPC (Transmit Power Control) lowers its power. The binding EU text is Implementing Decision (EU) 2022/179 (it repealed Decision 2005/513/EC); the US text is 47 CFR 15.407.

Sub-band	EU (Decision 2022/179)	US (47 CFR 15.407)
5 150 to 5 250 MHz	200 mW mean e.i.r.p., 10 mW/MHz; indoor, in vehicles and aircraft, limited outdoor use; 40 mW inside road vehicles; no DFS or TPC	access points 1 W conducted (6 dBi), client devices 250 mW; outdoor access points capped at 125 mW e.i.r.p. above 30 degrees elevation; no DFS
5 250 to 5 350 MHz	200 mW, 10 mW/MHz; inside buildings only; TPC and DFS	lesser of 250 mW or 11 dBm + 10 log B; DFS; TPC if 500 mW e.i.r.p. or more
5 470 to 5 725 MHz	1 W, 50 mW/MHz; indoor and outdoor; 200 mW in road vehicles (slave mode only); TPC and DFS	same as 5 250 to 5 350 MHz
5 725 to 5 850 MHz	not RLAN; 25 mW e.i.r.p. non-specific SRD under Decision 2006/771/EC	1 W conducted, no DFS or TPC

In the EU, TPC must give an average mitigation of at least 3 dB; equipment without TPC must lower its maximum mean e.i.r.p. and density limits by 3 dB. The decision also requires that DFS settings are not accessible to the user if changing them breaks compliance, including the country of operation and firmware that would disable DFS. Installations in large aircraft are allowed until 31 December 2028 at 100 mW mean e.i.r.p. (excluding 5 600 to 5 650 MHz in the upper band).

EN 301 893 sets the numbers a test lab checks:

DFS parameter	EN 301 893 V2.2.1, Table D.1	47 CFR 15.407(h)(2)
Channel availability check	60 s; 10 minutes for channels touching 5 600 to 5 650 MHz	60 s, master devices
Channel move time	10 s	10 s, normal traffic for 200 ms at most after detection
Channel closing transmission time	1 s	not stated as such
Non-occupancy period	30 minutes	at least 30 minutes
Detection threshold	-62 dBm at 10 dBm/MHz, never below -64 dBm	-64 dBm for 200 mW to 1 W e.i.r.p.; -62 dBm below 200 mW and 10 dBm/MHz

EN 301 893 also states that secondary (client) devices at 23 dBm e.i.r.p. or less need no radar detection unless used in fixed outdoor point-to-point or point-to-multipoint links. DFS is still the most failure-prone block of a 5 GHz campaign, and it cannot be added late.

Harmonised standards cited as of October 2026

Implementing Decision (EU) 2022/2191, amended seven times up to (EU) 2026/2003 of 4 September 2026, lists the references under the RED. Applying a cited standard in full gives presumption of conformity with Article 3(2).

Band or use	Standard cited	Note
Non-specific SRD, 25 to 1 000 MHz	EN 300 220-2 V3.1.1 and V3.3.1	V3.3.1 (2025-03) added by Implementing Decision (EU) 2025/2499 of 9 December 2025
SRD in data networks, 865 to 868 and 915 to 919.4 MHz	EN 303 659 V1.1.1	added by (EU) 2025/2499
Wideband data SRD, 863 to 868 and 915.8 to 919.4 MHz	EN 304 220-1 and -2 V1.2.1	network access points and terminal nodes
Fixed SRD in data networks, 870 to 876 MHz	EN 303 204 V3.1.1
Wideband data, 2.4 GHz	EN 300 328 V2.2.2	the only version cited
Non-specific SRD, 1 to 40 GHz (includes 10 mW at 2.4 GHz)	EN 300 440 V2.1.1	restriction on receiver categories 2 and 3
5 GHz WAS/RLAN	EN 301 893 V2.1.1 and V2.2.1	V2.2.1 (2024-11) added by (EU) 2025/893 of 14 May 2025

Where a harmonised standard is not applied, or only in part, Article 17(4) of Directive 2014/53/EU sends the equipment to EU-type examination (Module B plus C) or full quality assurance (Module H) for Article 3(2). Article 3(2) is not the whole RED either: Article 3(1) covers safety, health and EMC (field exposure is treated in the SAR procedures guide), and Article 3(3) lists requirements activated by delegated acts, of which points (d), (e) and (f) on network protection, personal data and fraud apply to many connected radios from 1 August 2025. Under Article 10(8) the instructions must state the frequency bands and the maximum radio-frequency power transmitted.

Regional differences: EU versus US

Aspect	European Union	United States
Band rules	Decision 2006/771/EC, Decision (EU) 2018/1538, Decision (EU) 2022/179, plus ERC Recommendation 70-03 for CEPT	47 CFR Part 15, Subpart C (15.231, 15.247, 15.249) and Subpart E (15.407)
Sub-GHz	863 to 870 MHz, plus 916.1 to 919.4 MHz in data networks	902 to 928 MHz
Typical sub-GHz limit	25 mW e.r.p.	1 W conducted (15.247) or 50 mV/m at 3 m (15.249)
Channel access	duty cycle or polite access	hopping dwell rules, no general duty cycle
5 GHz mitigation	DFS and TPC at 5 250 to 5 350 and 5 470 to 5 725 MHz	DFS in the same sub-bands, TPC only from 500 mW e.i.r.p.
Authorisation	manufacturer declaration (Module A) with a cited standard applied in full, otherwise Notified Body (Module B or H)	certification by a TCB for intentional radiators (15.201(b)); SDoC only for the exceptions in 15.201(a)

The US route is covered in FCC ID, grantee code and TCB; the EU split in self-declaration vs Notified Body.

Claims the texts contradict

Common claim (including earlier versions of this page)	What the text says
"ERC Recommendation 70-03 is the reference for EU SRD bands"	It is a CEPT recommendation. The binding EU text is Decision 2006/771/EC as amended, and 70-03 itself warns that its parameters may differ from the Commission decisions.
"902 to 928 MHz has no allocation in the EU"	Implementing Decision (EU) 2018/1538, as amended by (EU) 2025/650, harmonises 916.1 to 919.4 MHz for SRD in data networks and 916.1 to 918.9 MHz for RFID, with a Member State opt-out for defence use.
"The 2.4 GHz band allows 100 mW EIRP in the EU"	Only for wideband data transmission devices (band 57c, EN 300 328). Non-specific SRD get 10 mW e.i.r.p. (band 57a, EN 300 440).
"Duty cycle is measured over a window of often one hour"	The annex fixes the observation period at one continuous hour unless the row says otherwise.
"868 MHz is an ISM band"	Not in the ERC 70-03 list of ISM bands. 433.05 to 434.79 MHz, 2.4 GHz and 5.8 GHz are.
"DFS and TPC are mandatory across the 5 GHz band"	Not at 5 150 to 5 250 MHz. In the EU, TPC can be replaced by a 3 dB lower limit.
"In the US, DFS and TPC attach to 5.25 to 5.35 and 5.47 to 5.725 GHz whatever the power"	True for DFS. 15.407(h)(1) waives TPC below 500 mW e.i.r.p.
"US authorisation for these radios is SDoC or TCB"	15.201(b): intentional radiators under Part 15 need TCB certification, except the narrow cases in 15.201(a).
"433 MHz in the US falls under 15.231 or 15.240"	15.240 covers only 433.5 to 434.5 MHz RFID for commercial shipping containers. General 433 MHz control transmitters use 15.231.
"The 5 GHz RLAN rules come from Decision 2005/513/EC"	Repealed by Implementing Decision (EU) 2022/179.
"RED Article 3(3) is the cybersecurity article"	Article 3(3) lists points (a) to (i). Only (d), (e) and (f) concern network protection, privacy and fraud.

Consequences for product design

Band choice drives the protocol. At 25 mW e.r.p. and 1 % duty cycle, a sub-GHz node has 36 seconds of airtime per hour per sub-band unless it implements polite access. Size the application traffic against that before choosing a radio.
Power and antenna gain are a single budget. EU sub-GHz limits are radiated; US limits are conducted with a 6 dBi allowance. A high-gain antenna can push a product over either one.
Channel access must be implemented and proven. Polite access in EN 300 220-2, adaptivity in EN 300 328, DFS in EN 301 893: each is tested against timing and threshold values, not declared.
Lock the regulatory settings. Decision (EU) 2022/179 forbids user-accessible DFS settings that break compliance, including country selection. Plan firmware for this from the start.
Dual-market sub-GHz still means two configurations. The 916.1 to 919.4 MHz overlap helps, but EU limits, data-network conditions and national opt-outs keep the EU and US radios different.

Alliance programmes such as LoRaWAN, Wi-Fi and Bluetooth sit on top of these rules: they prove interoperability, the band rules prove lawful spectrum use.

A worked orientation

Case A: a sub-GHz IoT sensor for the EU and US. In the EU it transmits in 863 to 870 MHz under EN 300 220 Part 2, inside one Table 2 row (for example band 48, 25 mW e.r.p., 1 % duty cycle or polite access). In the US it moves to 902 to 928 MHz under FCC Part 15.247 (hopping or wideband digital modulation) or 15.249 (low field strength), and needs a TCB grant. Two configurations, two test campaigns.

Case B: a 2.4 GHz Bluetooth wearable. One radio serves both markets. In the EU the test follows EN 300 328 V2.2.2 (adaptive or non-adaptive regime); in the US, 15.247 for hopping or digital modulation. Outcome: one radio, two reports.

Case C: a 5 GHz Wi-Fi access point. To use 5 470 to 5 725 MHz at up to 1 W e.i.r.p. in the EU, it implements DFS and TPC (or accepts a 3 dB lower limit) and passes the EN 301 893 DFS tests; in the US, FCC Part 15.407 DFS applies in the same sub-bands. Outcome: the heaviest radio campaign of the three, planned from the start.

For receiver-side tests, see spurious emissions, receiver blocking and immunity tests. For the full EU path, start from the RED pillar.

Frequently asked questions

What is the difference between licensed and license-free spectrum?: Licensed spectrum is assigned to a named holder who gets an individual right of use. License-exempt spectrum is open to any device that meets published technical conditions, without an individual permit. In the EU, Decision 2006/771/EC makes short-range device bands available on a non-exclusive, non-interference and non-protected basis: a device may cause no harmful interference to radiocommunication services and may claim no protection from them.
What is the difference between EIRP and ERP?: EIRP (e.i.r.p.) is referenced to an isotropic antenna, ERP (e.r.p.) to a half-wave dipole, which has a gain of about 2.15 dBi. The same emission therefore reads about 2.15 dB higher in EIRP than in ERP. The EU texts state sub-GHz SRD limits in e.r.p. (for example 25 mW e.r.p. at 868 to 868.6 MHz) and limits above 1 GHz in e.i.r.p. (for example 100 mW e.i.r.p. for wideband data at 2.4 GHz). The FCC states 15.247 and 15.407 limits mostly as conducted power with a 6 dBi antenna allowance, and 15.249 limits as field strength at 3 metres.
Which ETSI standard applies to my band?: As cited under Implementing Decision (EU) 2022/2191 as amended: EN 300 220-2 (V3.1.1 or V3.3.1) for non-specific SRD from 25 MHz to 1 000 MHz, EN 300 328 V2.2.2 for wideband data at 2.4 GHz, EN 301 893 (V2.1.1 or V2.2.1) for 5 GHz WAS/RLAN. A 2.4 GHz non-specific SRD at 10 mW e.i.r.p. falls under EN 300 440, not EN 300 328, and SRD in data networks at 865 to 868 and 915 to 919.4 MHz under EN 303 659. Check the exact version against the current consolidated list.
Is 868 MHz European and 915 MHz American, with no overlap?: Not any more. 863 to 870 MHz has no US Part 15 equivalent, but the EU does harmonise part of the 915 MHz range. Implementing Decision (EU) 2018/1538, as amended by (EU) 2025/650, makes 916.1 to 919.4 MHz available for short-range devices in data networks (25 mW e.r.p., duty cycle 1 % or less, implementation deadline 1 October 2025) plus RFID and 500 mW network entries. Member States may opt out where the band is used for defence, and the US band runs 902 to 928 MHz with very different power rules, so a dual-market product still needs two configurations and two test campaigns.
What is duty cycle and why does it limit my throughput?: Decision 2006/771/EC defines duty cycle as the ratio, in percent, of the cumulated on-time of one transmitter over the observation period, which is one continuous hour unless the annex says otherwise. A 1 % limit means 36 seconds per hour, 0.1 % means 3.6 seconds. In most 863 to 870 MHz bands a device may instead use spectrum access and mitigation techniques of at least the performance described in the harmonised standard (listen before talk with adaptive frequency agility in ERC Recommendation 70-03, polite spectrum access in EN 300 220-2).
What are DFS and TPC in the 5 GHz band?: DFS (Dynamic Frequency Selection) detects radar and moves off the channel, TPC (Transmit Power Control) reduces power. In the EU, Implementing Decision (EU) 2022/179 requires both at 5 250 to 5 350 MHz and 5 470 to 5 725 MHz, not at 5 150 to 5 250 MHz, and equipment without TPC must cut its e.i.r.p. limit by 3 dB. EN 301 893 sets a 60 s channel availability check (10 minutes at 5 600 to 5 650 MHz), a 10 s channel move time and a 30 minute non-occupancy period. In the US, 47 CFR 15.407(h) requires DFS in the same two sub-bands (60 s check, 10 s move, 30 minutes non-occupancy), and TPC only for systems at 500 mW e.i.r.p. or more.
Does a certified radio module let me skip band compliance?: Not entirely. Under the RED the manufacturer of the final product assesses it in all possible configurations (Article 17(1)), so antenna gain, placement and firmware settings that change radiated power or channel access are back in scope. Under FCC rules, a module grant can be reused only within its grant conditions, and any intentional radiator under Part 15 needs certification by a TCB (47 CFR 15.201(b)).