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Outcome of the SE7 meeting held on 4-6 October 2017 at Sennheiser, Wedemark (Hannover), Germany

06 Oct 2017, 13:15

The SE7 meeting took place on 4-6 October 2017 at the Sennheiser premises in Wedemark, Germany.

The meeting was dedicated to discussions on the introduction of low power PMSE applications in the 960-1164 MHz band. A work item on this issue (SE7_28) was formally approved at the 77th meeting of WG SE in September 2017, following the request from WG FM.

The meeting discussed contributions from Administrations, the PMSE and the aeronautical communities and starting the work on a first draft for the expected deliverable (ECC Report).

Further details are available on the SE7 webpage.

Outcome of the SE7 meeting:

36 participants attended the meeting from administrations, industry, military from 12 CEPT countries, including Motorola Solutions, ATDI, DGAC, NATO, 450connect, APWPT, Bundeswehr - WTD 81, Deutsche Flugsicherung (DFS), Federal Armed Forces - National Frequency Management Agency (NARFA Germany), IRT, Sennheiser electronic, Shure Europe, Sony Europe, NARFA Hungary, TNO, Swedish Defence Materiel administration, EUROCONTROL and International Civil Aviation Organization (ICAO).

Work item SE7_28 on the introduction of low power PMSE applications in the frequency band 960-1164 MHz:

Background information from previous SE7 meetings:

  • LS from FM to WG on sharing studies in 960-1164 MHz (SE7(17)037)
  • Background information on 960-1164 MHz band (SE7(17)038)

At the last WG FM meeting at the end of May, the group sent a LS to WG SE asking for studies for the introduction of low power PMSE in the 960-1164 MHz frequency band. The liaison statement specifies the scope for the technical studies. FM51 developed additional background information for the studies, including considerations on the use of the band by incumbent services (i.e. civil and military radionavigation and communication systems), the use of adjacent bands around the band under consideration by MFCN and RNSS, and a description of possible scenarios for compatibility studies.

Establishment of the WI and background information from WG FM and WG SE:

  • LS from FM to SE on sharing studies in 960-1164 MHz including background information (SE7(17)085 and SE7(17)085A1, WGFM)
  • Definition of the new SE7 work item (SE7(17)086, WGSE)

Following the request from WG FM, WG SE created at its 77th meeting a new work item on the introduction of low power PMSE applications in the frequency band 960-1164 MHz. The deadline for completion of activities on this WI is September 2019 (date for the publication of the expected deliverable).

SE7 briefly looked at the final wording of the WI (already in the WPDB) and the LS from WG FM (SE7(17)085) which defines the scope of the WI. The Attachment 1 of the LS from WG FM is the same document already submitted to the June meeting of SE7 (SE7(17)038), which provides background information of aeronautical systems operating in the range 960 – 1164 MHz.

 

New discussions during the SE7 meeting:

Mr. Volker Bartels (President of Research & Quality, Sennheiser Electronic) gave an introductory speech indicating the requirements for audio PMSE for production:

  • Audio formats intended for production allow limited compression, in order to be compatible with future audio formats
  • Need for low latency on audio content (synchronization between audio and video).
  • Wide range of use cases
  • Need for sharing studies to allow audio PMSE applications to operate in the Air-Band, after the loss of spectrum for PMSE due to the two digital dividends (i.e. 800 MHz and 700 MHz bands).
  • Important role in economy

 

Mr. Dirk Hothan (Management Systems, Sennheiser Electronics) showed a presentation focusing on the status of current European aviation regulations.

The presentation triggered some discussions highlighting on one hand the possibility to share the band as shown in the UK, but stressing on the other hand the need to adjust international and national regulations in order to avoid the responsibility and liability in case of accidents that may occur by sharing the band with aeronautical systems which are used for safety of life applications (statement from Eurocontrol).

SE7 Chairman showed a interactive software made available at the Ficora’s website in which it is shown that which parts of the bands 174-230 MHz and 470-694 MHz can be used for wireless microphones (license exempt) in Finland.

Vaughan John (OFCOM UK) indicated the plans in the UK to allocate the centre gap of the 700 MHz band for SDL, and that the UK is considering the use of the 9 MHz guard band for PMSE.

Joachim Wollweber (DFS) showed a presentation highlighting the characteristics of aeronautical systems including frequency bands, propagation models, antenna patterns, operation scenarios, etc. that can be used for sharing studies.

 

  • NATO L Band Overview (SE7(17)084, NATO)

Serge Basso (NATO) showed in his documents the different frequency bands used for aeronautical systems’ applications. In particular, it showed the characteristics of the Distance Measuring Equipment (DME) system, the Tactical Air Navigation (TACAN) system, secondary surveillance radars and Automatic Dependant Surveillance (ADS) systems (e.g. universal access transceiver, UAT).

The presentation focuses on the example of the compatibility study between Link 16 (i.e. a Tactical Data Link) versus DME/TACAN & GNSS to show the complexity of this kind of study. Link 16 is a spread spectrum system used for secure jam-resistant communications, navigation and identification. It is a military tactical data exchange network used as primary data link by NATO nations.

In summary, the military community expects studies involving PMSE to be as accurate as the study between Link 16 and DME/TACAN and Link 16 vs. GNSS, in order to protect the ARNS. These studies are difficult due to the fact that there are no theoretical models for EMC analysis, that they require practical tests on equipment (with near and far signals) and that there are a variety on interference criteria depending on the system (i.e. different for DME/TACAN beacons and interrogators).

 

  • PMSE Equipment EMC Evaluation Requirements (SE7(17)083, NATO)

The document provides test scenarios and parameters for the studies in order to protect DME receivers. The document includes information on measurement campaigns and hardware testbeds to assess the impact into DME, as a theoretical model for DME receiver’s susceptibility to interfering signals has not been developed so far. The document includes indicative PMSE parameters for hardware testbeds purposes.

It was agreed to include material from this document in the draft report.

 

  • Compilation PMSE in the band 960-1164 MHz (SE7(17)082 and SE7(17)082A1, APWPT)
  • Compendium of systems and applications in the band 960 - 1125 MHz (SE7(17)092, DFS Germany)

The Annex to the contribution (that takes account of the information provided in document SE7(17)092 from DFS Germany) is the outcome of the work of a preparatory team for SE7 activities related to this WI, which managed to collect technical parameters and suggestions for the compatibility studies to be carried on in SE7. The document has already 113 pages and includes definitions, parameters and scenarios.

It was agreed to use this document as baseline for the SE7 studies.

 

  • PMSE Trials 960-1000 MHz October 2017 (SE7(17)087, Copsey)

The document is an initial technical report on practical PMSE testing performed in the period June 2016 –October 2017.

The testing was done in several sites in the UK. In particular, the document establishes similarities between the sharing situation between TV Broadcasting in the UHF band and DME transponders operating in that frequency band, as both are located in fixed positions, having a defined coverage area and operating in defined frequencies. This allows the plotting of a geographical availability map (similar to the white-space concept in the broadcasting bands). With this, they identify the following available spectrum for PMSE in the band for different locations:

  • BBC “The Mailbox” studios (Birmingham, 10 km from the airport): 75 MHz available, 15 MHz of which have some risk of interference into PMSE from DME.
  • Sky studios (Osterley by London, about 10 km from Heathrow airport): 60 MHz available, 8 MHz of which have some risk of interference into PMSE from DME
  • BBC “Elstree” studios (London): 60 MHz available, 9 MHz of which have some risk of interference into PMSE from DME
  • Cambridge theatre (central London): 61 MHz available, 10 MHz of which have some risk of interference into PMSE from DME
  • BBC “Pacific Quay” studios (Glasgow, Scotland, about 10 km from the airport): 83 MHz available, 17 MHz of which have some risk of interference into PMSE from DME

 

It was clarified that intermodulation products were not considered in the testing.

APWPT announced a lab test taking place in 2018, in order to assess the effect of airborne systems into PMSE in a stable environment, in cooperation with civil aviation authorities.

The document was discussed extensively and SE7 decided to postpone the decision of including the material from this document into the draft report, once clarifications on the methodology used and interpretation of results are provided.

It was clarified that the intention of the document was only to provide an indication on a possible use for audio PMSE in the band in the UK.

 

  • Audio PMSE Characteristics (SE7(17)088, ANFR)

The contribution provides characteristics for audio PMSE in ETSI and CEPT documentation. The intention is to define the characteristics to be used for sharing studies in the band 960-1164 MHz.  It also raises the question of the level of quality of service which is expected for audio PMSE devices, for which further information is needed. Also, ANFR asked OFCOM UK if they could provide the full coexistence studies that led to the decision of making the band available for audio PMSE in the UK.

Matthias Fehr (APWPT) proposed the addition of Recommendation ITU-R  BT.1871: “User requirements for wireless microphones “. Further to that, Brian Copsey indicated that he will provide references to a few more ITU-R documents relevant for the studies.

Vaughan John (OFCOM UK) stated that no theoretical studies were performed in the UK, but rather practical testing involving the Civil Aviation Authority (CAA) and the Ministry of Defence. This practical testing included Link 16. This information is publicly available and will be provided to the meeting.

Loftur Jonasson (ICAO) stated that it is necessary to have specific information on equipment in use for compatibility studies.

 

  • System parameters for services in 960-1164 MHz band (SE7(17)090 , PTS, Sweden)

Sweden proposes to define a set of technical parameters to be used in studies, defining responsible conveners to provide those technical parameters.

 

The Office also reminded the importance of agreeing on scenarios (which should normally cover both worst-case and realistic scenarios) and parameters at the beginning of the process, in order to optimise the use of time during the study period. Of course, experience shows that studies are made in an iterative process and parameters might vary during the course of the studies, but if some agreement in the first stages of studies can be achieve, this would be in the benefit for all.

There was a short discussion on a balance of considering realistic scenarios or in other words, intended use cases, but without excluding corner use cases that might result from an unintended use, but nonetheless also possible to happen in reality.

The group agreed that both indoor and outdoor scenarios should be included.

 

  • PMSE 960 MHz band Proposed parameters for study (SE7(17)091, OFCOM UK)

The UK proposes to use the parameters contained in Report ITU-R M.2205 for ICAO airborne systems, currently in use in Europe (i.e. Annex 1, Table 1-1 with parameters for airborne Tx and Table 1-2 for airborne Rx).

Section 6.1 of this Report indicates that parts of the band (960-976 and 1151-1156 MHz) are not used by airborne navaid transmitters and contain no fixed ground-based assignments in some countries, but it refers to compatibility with another system also under ICAO’s control.

Vaughan John reported that, all in all, in the UK there are about 60 MHz available for audio PMSE in the band.

 

Other business: None.

 

Next SE7 meetings:

  • 16-18 October at ECO. Dedicated to WIs SE7_25 and SE7_26 (LTEin400) and WI SE7_27 (Cross-border coordination thresholds)
  • 27-29 November at ECO. Dedicated to WIs SE7_25 and SE7_26 (LTEin400) and WI SE7_27 (Cross-border coordination thresholds)
  • 30 January – 1 February 2018 at ECO. Dedicated to WI SE7_28 (PMSE in 960-1164 MHz).