ECC PT1 agreed that a Correspondence group should be issued to progress the drafting of the ECC Report on least restrictive technical conditions for 1427-1452 and 1492-1518 MHz and the relevant parts of the draft ECC Decision as per ToR in SWG-C Annex 14. The CG will be convened by Mr. Guillaume Lebrun and will base its work on the drafts created during ECC PT1 #54 (SWG-C Annex 12) and the relevant parts of SWG-A Annex 1.

Dear colleagues,

As discussed during the Cascais meeting, It is probably worth focusing first on the draft ECC Report on L-band. I attach a base document, please make sure to use revision marks when contributing.

Note that some sections will need to be aligned after ECC with the final content of report 263. I will propose a web-meeting following ECC, so that we can finalise the sections diretcly related to report 263 and focus on the outstanding issues.

I also attach the collection of input to Cascais meeting to the Annex 2 of the draft decision on L-band. This material comes from the UK () and multicompany () contributions. We can progress on Report and Annex 2 in parallel. Note that I included the current status of Annex 1 for information, but that modification of the Annex 1 is out of scope of our CG since it is conducted under SWG A.

Looking forward to your comments/ and contributions!

Guillaume

Dear Guillaume and All,

Please find attached documents showing some proposed changes to the Draft Report, the main body of the Decision, and the Annexes of the Decision.

- Paul 

Thanks Paul,

We were actually modifying the documents in parallel :-)

On your modifications to the decision itself (apart from Annex 2), this is out of mandate of the correspondence group since this is for SWG A, so I would encourage you to submit them directly to PT1.

I compiled my changes with yours in a single document, taking our proposed Annex to the decision as an annex to the report. May make it easier to follow these things in parallel. So please use the document attached as the base version.

Note that I include some new elements in the report on:

-what the industry expects in terms of technological possibilities in 1427-1432,

-the interaction with ECC Decision 13/03.

Paul: You were proposing explicit limits in your annex 2 for emissions below 1492. Please have a look at the new section 6 that discusses this issue.

Guillaume

Hi All,

I have of course been following this work and I am pleased to see the progress.

I noted a few new proposals that partly stem from Report 263 but with a different spin added. I have, in the attached, copied in the original text from Report 263 with a couple of tiny changes to make the text match this report.

The areas involved were very contentious during the development of Report 263 so it is important not to open up old battlefields

I will wish you good luck in finalising this report

Best regards

Torben

[EDIT: File now attached]

Dear All,

Please see further changes from Inmarsat in the attached document.  

Noting that the EC mandate makes specific reference to protection of airports and seaports, and also that the ECC asked that PT1 includes information on mitigation techniques for dealing with protection of MSS at airports, we have proposed some additional text for that in particular.  All new changes should be highlighted in green.

- Paul

Hi All,

I had hoped we could have ended the discussion with a flexible statement about that there may be a need to protect MSS in sea and airports. This however would appear not to be the case so it may be better to spell out what protection of MSS may mean for terrestrial operation in sea and airports. It may be good to clarify this is the text in the draft report.

According to Report 263 the requirements are:

• The minimum in-band blocking characteristic for land mobile earth stations receivers from a 5 MHz broadband signal interferer (LTE) operating below 1518 MHz shall be −30dBm above 1520 MHz[1];
• The base station unwanted emission limits e.i.r.p. for a broadband signal interferer (LTE) operating below 1518 MHz shall be −30dBm/MHz above 1520 MHz. This figure is 10 dB more stringent than ECC Decision (13)03 due to a different service in the adjacent band.

This means that where an administration feels there is a need to protect MSS in seaports and airports that they in line with the requirements set out above may ask the satellite operator to avoid using the frequency range 1518 to 1520 MHz at these locations.

[1] when the MES operates above 1520 MHz

Regards

Torben

Torben, the "solution" you suggest does not resolve the issue, even if administrations did want to remove 2 MHz of MSS spectrum from maritime and aero MSS operations.  To protect current ship earth stations and aircraft earth stations against blocking, removing 2 MHz spectrum from the MSS does nothing and the required separations remain unchanged at several km.  In the most optimistic case, considering the IMT OOB emissions above 1520 MHz and considering improved blocking of future MSS terminals, the required separation distance for MSS terminals operating above 1520 MHz is more than 1km.

I am sure this is manageable with careful deployment of IMT base stations and without major constraint for IMT operators.  But considering that maritime and aero MSS terminals are used for safety related applications, admins will probably want more detail about how protection could be ensured - as the ECC minutes and the EC Mandate suggest.

- Paul

Hi Paul and all,

Sorry to disagree with you Paul,

We understand what you are saying but the bottom line is that with the new requirements (both MES receiver blocking and IMT OOBE) are specified from 1520 MHz and therefore the future safe way of providing protection to MSS at sea and airports is not to use the frequency range 1518 to 1520 MHz at these locations. We are not talking about taking away the spectrum but about not using it at these limited locations where protection of MSS is wanted. We have from ECC Report seen that this part of the spectrum is working fine for ships at sea, for aeroplanes in flight and at normal rural locations so the spectrum is certainly not removed.

MSS may of course experience a bit of interference on legacy equipment, this is only to be expected, it is a known temporary side effect each time a deployment changes. We assume this is limited to the part of the legacy equipment which actually covers down to 1518 MHz. Most legacy equipment will only cover down to 1525 MHz so should not be a problem and is in any case not covered by the provisions of ECC Report 263.

The reason why the exclusion of the band 1518 to 1520 MHz in sea and airports is working better is that whilst we are confident that there will soon have equipment on the market that will meet the blocking requirement at 1520 MHz there is still a lot higher OOBE at the frequencies below 1520 MHz that is not easily mitigated. We are talking about a mitigation of approximately 29 dB to be down to the same level of OOBE as is required at above 1520 MHz and in terms of power reduction or separation distance this is not practical. Whilst the 29 dB more OOBE in the 1518 to 1520 MHz range do not guarantee interference, as we can see from the results in ECC Report 263 for normal rural areas, it at the same time most certainly do not guarantee protection at the sea and airports.

So, whilst we understand your wishes, we do not see that your proposals provide a practical safe solution for now or the future.

Regards

Torben

Hi Torben, Paul and all,

I don't have strong position on the issue, however it is a normal practice to limit deployment of base station in some bands around airports (don't have muchof experience with seaports), even for adjacent band cases. If there is a need of more that few hundred meters separation even in the case of new OOBE and selectivity requirements and with 1518-1520 MHz band excluded from MSS operation, it should be clearly stated. If MSS is used for safety applications, very logical action is to limit base station deployment by EIRP or by location (or by field strength requirement).

It is ECC PT1 job to clearly explain the situation and provide measures to safeguard critical applications, if there is a risk of intereference. So there might be a need to include the list of measures, which could be than envistigated by administartions on the case-by case basis. So it would be beneficial to work and Paul's proposal and maybe edit some parts, which might be controvertial to other parties..

Best regards,

Vadim.