ECC actions on interference from 5 GHz RLAN into meteorological radars Bruno Espinosa, European Communications Office EG RRS 04, Brussels, 17th April 2018

Background ECC Decision(04)08 and EC Decision 2005/513/EC on the harmonised use of the 5 GHz bands for WAS/RLANs WAS/RLANs in the bands 5 250-5 350 MHz and 5 470-5 725 MHz shall use mitigation techniques that give at least the same protection as the detection, operational and response requirements described in EN 301 893 to ensure compatible operation with radiodetermination systems. Cooperation between ETSI and ECC to define Dynamic Frequency Selection (DFS) requirements and related test procedures in versions of EN 301 893. Footer copy here

First set of actions – 2011-2014 Interference cases from 5 GHz RLANs into meteorological radars reported in 2011. First questionnaire from ECC/WG FM (October 2011): 17 countries reported more than 200 interference cases which occurred during 2010/2011 Extensive analysis of the interference cases and the 2013 ADCO RTTE campaign ECC Report 192 (02/2014, updated 11/2017): The Current Status of DFS (Dynamic Frequency Selection) in the 5 GHz frequency range Footer copy here

ECC Report 192 A considerable number of the reported interference cases: caused by equipment where the DFS mechanism was disabled. Alteration/ disablement of DFS settings still possible by the user (despite ETSI EN 301 893 version 1.4.1 and higher does not allow the user to disable DFS or alter the DFS settings). In some of these cases, Notified Bodies had issued a positive opinion to this non-compliant equipment. In some cases, where DFS was disabled, re-enabling DFS did not cause the equipment to detect the radar. The DFS did not function as intended (non-compliant DFS). no problem identified in ECC Report 192 with regard to short comings in the specifications of the DFS mechanism, as included in relevant versions of EN 301 893 (i.e. – v1.5.1 and above). Footer copy here

ECC Report 192 Most of the reported interference cases remained ultimately inconclusive because of missing information or incomplete investigations. Identifies a range of possible solutions and actions: Guidance to manufacturers and notified bodies; Guidance to national enforcement authorities. Annex 2 (updated November 2017): example of national measures taken to solve the interference cases (F, CZ) based on recommended guidance. Footer copy here

Second set of actions – 2017-2018 Despite ECC Report 192, cases of interference from 5 GHz RLAN into meteorological radars still reported. Letter from EUMETNET (January 2017) triggered a second set of actions in ECC: New questionnaire on interference cases (May-October 2017) List of relevant actions (updated November 2017) Cooperation with ADCO RED for ADCO campaign 2018 Monitoring of interference cases (as part of the annual interference statistics) Footer copy here

2017 questionnaire on 5 GHz interference cases 37 CEPT administrations responded, 24 of which reported around 554 interference cases (+ additional short term cases) of 5GHz RLAN into meteorological radars, for the period 2015 - 2016. Footer copy here

2017 questionnaire on 5 GHz interference cases Reported cases for 2015-2016 almost exclusively originate from equipment in fixed outdoor installations using directive antennas; Mixed answers on DFS operation: DFS mechanism was either active, inactive or inoperative; Many cases solved by reconfiguration of the RLAN equipment, e.g. change of operating channel, DFS activation, rebooting or firmware/software upgrade, removal of equipment malfunction; Limited information about version of EN 301 893; Additional short-term interference cases not included in the replies; More about the questionnaire assessment here. Footer copy here

List of actions identified by ECC (November 2017) Make sure that ECC Report 192 findings and guidelines are fully applied by national enforcement authorities: CEPT administrations invited to provide national examples (Annex 2 of ECC Report 192); Prepare awareness and information actions from national radio administrations: information on the topic and on relevant national actions included on the WAS/RLAN page of the ECC website; Continue the monitoring of the issue of interference into 5 GHz meteorological radar: after the 2017 questionnaire, issue specifically covered in the annual interference statistics questionnaire; questionnaire on 2017 interferences: deadline for answers 3 April 2018, preliminary results available soon. Footer copy here

List of actions identified by ECC (November 2017) Request interference management authorities to collect appropriate information on the equipment which caused interference: cooperation with ADCO RED for its 2018 campaign; Consider the possibility to release a “Name and Blame” list of non-compliant 5 GHz RLAN equipment: no activity carried out yet at the ECC level; Collect information in order to assess the level of compliance of 5 GHz RLAN: this would assist future discussions on whether it would be appropriate to activate Article 5 of the RE Directive for 5 GHz RLAN. Footer copy here

Thanks for your attention bruno.espinosa@eco.cept.org www.cept.org/eco www.cept.org/ecc