Commission Implementing Decision (EU) 2025/2425 of 2 December 2025 on the harmonisation of the 3800-4200 MHz frequency band for the shared use by terrestrial wireless broadband systems capable of providing local-area network connectivity in the Union (notified under document C(2025) 8146)

Article 1

This Decision establishes the harmonised technical conditions for the availability and efficient shared use of the 3 800-4 200 MHz frequency band, for low- and medium-power terrestrial wireless broadband (WBB LMP) systems capable of providing local-area network connectivity in the Union.

Article 2

For the purposes of this Decision:   ‘radio altimeter’ means a downward-looking radar ranging system that measures the height of an aircraft above terrain and obstacles with a high degree of accuracy, integrity, and availability, during all phases of flight.

Article 3

By 30 September 2026, Member States shall designate and make available on a non-exclusive basis the 3 800-4 200 MHz frequency band for WBB LMP systems in compliance with the harmonised technical conditions set out in the Annex.

Article 4

Member States shall ensure, in compliance with the relevant harmonised technical conditions set out in the Annex, that the WBB LMP systems appropriately protect: (a) Earth stations in the Fixed Satellite Service (FSS) for space-to-Earth communications authorised to operate within the 3 800-4 200 MHz frequency band across the Union and below 3 800 MHz; (b) systems in the Fixed Service (FS) operating within the 3 800-4 200 MHz frequency band; (c) terrestrial systems providing wireless broadband electronic communications services (WBB ECS) within the 3 400-3 800 MHz frequency band; (d) radio altimeters in the aeronautical navigation service (ARNS) operating within the 4 200-4 400 MHz frequency band; (e) VLBI Global Observing System stations on the Union’s territory, where necessary and taking due account of their regulatory status.

Article 5

Member States shall facilitate cross-border coordination agreements to enable operation of the WBB LMP, and also in accordance with Article 4, taking into account existing regulatory procedures and rights, and relevant international agreements.

Article 6

Member States shall report to the Commission on the implementation of this Decision by 31 December 2026. Member States shall monitor the use of the 3 800-4 200 MHz frequency band, including the co-existence between WBB LMP systems and other systems referred to in Article 4. Member States shall report their findings to the Commission upon request or at their own initiative.

Article 7

This Decision is addressed to the Member States.

TECHNICAL CONDITIONS REFERRED TO IN ARTICLE 3 AND 4

ANNEXSupplementary provisions

ANNEX TECHNICAL CONDITIONS REFERRED TO IN ARTICLE 3 AND 4 1.    Definitions For the purposes of this Annex, the following definitions apply: AAS (active antenna systems) means a WBB LMP base station and an antenna system where the amplitude and/or phase between antenna elements is continually adjusted resulting in an antenna pattern that varies in response to short term changes in the radio environment. This is intended to exclude long term beam shaping such as fixed electrical down tilt  ( 1 ) . Synchronised operation means operation of two or more different time division duplex (TDD) networks, where simultaneous uplink (UL) and downlink (DL) transmissions do not occur, that is at any given moment in time either all networks transmit in downlink or all networks transmit in uplink. This requires the alignment of all DL and UL transmissions for all TDD networks involved as well as synchronising the beginning of the frame across all networks  ( 2 ) . Unsynchronised operation means operation of two or more different TDD networks, where at any given moment in time at least one network transmits in DL while at least one network transmits in UL. This might happen if the TDD networks either do not align all DL and UL transmissions or do not synchronise at the beginning of the frame  ( 3 ) . Semi-synchronised operation means operation of two or more different TDD networks, where part of the frame is consistent with synchronised operation, while the remaining portion of the frame is consistent with unsynchronised operation. This requires the adoption of a frame structure for all TDD networks involved, including slots where the UL/DL direction is not specified, as well as synchronising the beginning of the frame across all networks. Equivalent isotropically radiated power (EIRP) is the product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna (absolute or isotropic gain) Total radiated power (TRP) is a measure of how much power a composite antenna radiates. It equals the total conducted power input into the antenna array system less any losses in the antenna array system. TRP means the integral of the power transmitted in different directions over the entire radiation sphere as shown in the formula: where P(θ,φ) is the power radiated by an antenna array system in direction (θ,φ) given by the formula: where P Tx denotes the conducted power (measured in Watts), which is input into the array system, and g(θ,φ) denotes the array systems directional gain along the (θ, φ) direction. 2.    General Parameters Within the 3 800-4 200 MHz frequency band: (1) the duplex mode of operation shall be time division duplex (TDD); (2) the assigned block sizes (or ‘channels’) shall be in multiples of 5 MHz (Figure 1); (3) the lower frequency limit of an assigned block shall be aligned with or spaced at multiples of 5 MHz from the lower band edge of 3 800 MHz; (4) multiple adjacent blocks of 5 MHz can be combined to obtain a wider channel; (5) the transmission of base stations and terminal stations shall be in compliance with the technical conditions specified in Section 3 and Section 4, respectively. Figure 1 3 800-4 200 MHz frequency arrangement 3.    Technical conditions for base stations Table 1 defines the maximum EIRP within an assigned block (‘in-block EIRP’) per cell for WBB LMP base stations operating in the 3 800-4 200 MHz frequency band. Table 1 Maximum in-block EIRP per cell for WBB LMP base stations operating in the 3 800 - 4 200  MHz frequency band Type of base station EIRP per cell (Note 1 and Note 2) Low power base station ≤ 24 dBm/channel for BW ≤ 20 MHz ≤ 18 dBm/5MHz for BW > 20 MHz Medium power base station ≤ 44 dBm/channel for BW ≤ 20 MHz ≤ 38 dBm/5MHz for BW > 20 MHz Note 1: In a multi-sector site, the value per ‘cell’ corresponds to the value for one of the sectors. Note 2: Higher EIRP levels may be authorised by national administrations in exceptional and duly justified cases, provided that protection of FSS receiving Earth stations and FS links (where appropriate at national level) in the band as well as terrestrial systems providing WBB ECS below 3 800  MHz and radio altimeters operating in the 4 200 - 4 400  MHz frequency band is ensured, taking into account their future development, including in the neighbouring EU Member States. The network coverage shall remain local (i.e. no nationwide networks). Explanatory note to Table 1: for the protection of terrestrial systems providing WBB ECS operating below 3 800 MHz, coordination may be required at national and/or cross-border level  ( 4 ) . Table 2 defines the maximum unwanted emission levels for WBB LMP base stations above 4 200 MHz. These levels will provide a general protection of radio altimeters  ( 5 ) operating in the 4 200-4 400 MHz frequency band. For WBB medium power base stations with AAS operating in the 4 100-4 200 MHz frequency band, that are deployed in close proximity to those airports which support precision approach procedures, coordination at national level may be needed  ( 6 ) . Table 2 Maximum unwanted emission levels above 4 200 MHz for WBB LMP base stations Frequency range Non-AAS base station EIRP limit [dBm/5MHz per cell] (Note 1) AAS medium power base station TRP limit [dBm/5MHz per cell] 4 200 -4 205  MHz 11 1 4 205 -4 240  MHz 8 -3 Note 1: In a multi-sector base station site, the value per ‘cell’ corresponds to the value for one of the sectors. Explanatory note to Table 2: The spurious domain in those technical conditions for a base station operating in the 3 800-4 200 MHz frequency band starts at 40 MHz from the band edge and the corresponding spurious emission limits are set in ERC Recommendation 74-01  ( 7 ) . 4.    Terminal Stations in-block requirements Maximum WBB LMP terminal station power: 28 dBm TRP (including a 2 dB tolerance). For fixed terminal stations, an in-block EIRP limit may be set out at national level, provided that protection of in-band and adjacent band incumbent services and cross-border obligations are fulfilled. Transmission power control is mandatory and shall be activated. ( 1 )   Non-AAS (non-active antenna systems) refers to WBB LMP base station transmitters which uses a passive antenna with a fixed antenna pattern. It may be possible to apply long term electrical beam steering to non-AAS, but non-AAS cannot respond to short term changes in the radio environment. ( 2 )   I.e. common phase clock reference. ( 3 )   I.e. no common phase clock reference. ( 4 )   Examples of coordination may include geographical/frequency separation, defining a maximum allowed power level (pfd) at the border of the WBB LMP licensed area, synchronised operation, specific sub-cases of semi-synchronised operation which only allow downlink to uplink modifications to the WBB LMP network compared to the frame structure of the WBB ECS and/or defining the maximum unwanted emissions below 3 800 MHz depending on location of WBB LMP in relation to WBB ECS. ( 5 )   This includes radio altimeters installed in large commercial aeroplanes and regional aircraft, which constitute the vast majority of radio altimeters in operation. ( 6 )   Examples of coordination may include no AAS medium power base station deployment closer than 1 200 m from the runway threshold and 40 m laterally from the edge of the runway, or AAS medium power base stations in compliance with emission levels meeting the spurious emission limit between 4 200 and 4 240 MHz. ( 7 )   ERC Recommendation 74-01 ‘Unwanted emissions in the spurious domain’, last updated on 1 October 2021.