Correspondence group on 26 GHz sharing and compatibility studies

Terms of reference

The correspondence group has been set up to make progress on sharing and compatibility studies for the 26 GHz band between the regularly scheduled ECC PT1 meetings.

1.     The correspondence group will consider studies on sharing and compatibility with services in the frequency band 24.25-27.5 GHz and adjacent bands, as appropriate, including passive services in the frequency band 23.6-24 GHz

2.     The group will develop a document for consideration in ECC PT1 that brings together the inputs it has received on the sharing and compatibility issues

3.     The group may prepare draft liaisons to relevant groups for approval by ECC PT1

4.     The group will report to ECC PT1 one week before the start of the next meeting

It is noted that ITU-R has set a deadline of 31 March 2017 for parameters and propagation models to be provided by the involved Working Parties for TG 5/1 studies. However, any preliminary analysis would be welcome in this correspondence group, in order to review methodology and seek initial views on the modelling of sharing scenarios.

Correspondence group convener: Robert Cooper (G) as CEPT coordinator for WRC-19 AI 1.13

Working methods: ECO forum (in the SWG AI 1.13 section) and web-meetings as appropriate

These Terms of Reference will be reviewed at each ECC PT1 meeting

All,

You will have seen the e-mail from the PT1 Chairman and the Terms of Reference posted on this Forum. 

Noting the holiday period, we do not have a lot of time before the next ECC PT1 meeting.  However, it would be useful to receive any initial studies that you have been working on.  We will need to conclude this initial activity within this CG and report to ECC PT1 by the 6^th January. 

I have been working on the attached document which provides an outline of a working document.  This can be used to keep track of the inputs and can be used if we need to develop any deliverables in the future.  Any comments on this document would be welcome. 

Best regards,

Robert

Dear Robert, all,

Please find an initial analysis on sharing between IMT2020 and Inter-Satellite Service (ISS) in the 26 GHz band attached. This analysis will need to be updated when the IMT2020 parameters are agreed by ITU-R WP5D in February 2017.  We would welcome comments to the analysis from this CG.

Thank you.

Regards,
Tuck Poon
(Ofcom, UK)

Dear Robert, all,

We (James Richardson, Ofcom) have also done an initial analysis on sharing between IMT2020 and EESS in the 26 GHz band (attached). Like the initial DRS analysis, this work will be revised once the IMT2020 parameters are agreed in February 2017. We would like to hear any comments or feedback via this correspondence group.

Many thanks.

Regards,
Tuck
(Ofcom, UK)

Hi Tuck and James,

Many thanks for your studies which are very much appreciated.

If I may, I would like to offer the following comments as ESA on the study related to the exclusion zones around receiving EESS earth stations. I will let AIRBUS comment on the study related to ISS since they are providing the EDRS service to ESA:

• I understand the parameters for 5G will only be available later on next year, however I noticed that the antenna height for AP was taken as 10 m, whereas in [3], it’s provisionally given as 20 m, if I am not mistaking.
• In [2], the antenna discrimination for 62 dBm AP at 5° elevation is given as 22 dB, whereas a value of 27 dB has been considered in this study. A 10° downtilt was also considered, however this does not prevent the AP to point above -10° elevation, thus decreasing the available antenna discrimination. That will have to be discussed further once the 5G parameters are available, including further details on the antenna.
• The study is limited to GSO EESS systems, which is indeed one usage of the band for instance for MTG from EUMETSAT. However the case of NGSO EESS and SRS satellites will also have to be addressed.
• The study addresses the single entry case for AP, which is indeed what should be done first. The aggregate interference from a deployment of several AP and UE will then have to also be addressed as well at a later stage.

Although we are still waiting to the final 5G parameters, we have, using similar parameters (but a 20 m antenna height and a 22/29 dB antenna discrimination for the 62/75 dBm AP), conducted our own single entry assessment regarding the Redu 12 m dish earth station tracking NGSO EESS satellites and the Cebreros 35 m dish earth station tracking near Earth SRS missions around Lagrangian points. The preliminary results obtained show a maximum separation distance of 8 km from the EESS earth station in Redu and of 30 km from the more sensitive SRS earth station in Cebreros.

Best regards,

Jean-Yves Guyomard

Dear Jean-Yves,

Thanks for your comments and apologies for the slow reply. Here's James' comments.

Tuck

----------

Dear Jean-Yves,

Many thanks for taking the time to review our study on 5G compatibility with EESS receiving earth stations. I’ll take each of your comments in order:

• Antenna height – Yes you are right, WP5D’s provisional AP antenna height for suburban is [20m]. Once WP5D has finalised parameters for antenna height (and indeed all other relevant 5G parameters), we intend to update our study. Related to this, we would also need to consider the relevant downtilt according to the height of the 5G antenna.
• Antenna discrimination –  Our value of 27 dB comes from the AP beam boresight pattern (Exhibit B-7 in reference [2]). Because we assume a 16x16 antenna array for both 62 and 75 dBm power configurations, the pattern shows the 10 degree point on the pattern to hit the y-axis at about -15 dB. The boresight gain is at approximately +12 dB, hence an overall relative gain of -27 dB from boresight. For comparison, reference [2] quotes -29 dB relative gain towards the satellite for an angle of 11 degrees (6 degree downtilt + 5 degree elevation to satellite) so -27 dB for 10 degrees would seem about right. Again, once the antenna information is finalised we can update our study.
• NGSO / GSO –  We agree the NGSO case will also need to be studied. The reason we didn’t study it is because there are no known NGSO earth stations in the UK from which to base our parameters on. We are pleased to see that ESA has some preliminary results for the NGSO EESS case, and also for SRS.
• Single entry / aggregate interference – Agreed, the case of aggregate interference from 5G deployments will need to be studied later.

Best Regards,

James Richardson

------------------------------------------------

On 12/12/16 14:00 Jean-Yves Guyomard wrote:
"

Hi Tuck and James,

Many thanks for your studies which are very much appreciated.

If I may, I would like to offer the following comments as ESA on the study related to the exclusion zones around receiving EESS earth stations. I will let AIRBUS comment on the study related to ISS since they are providing the EDRS service to ESA:

• I understand the parameters for 5G will only be available later on next year, however I noticed that the antenna height for AP was taken as 10 m, whereas in [3], it’s provisionally given as 20 m, if I am not mistaking.
• In [2], the antenna discrimination for 62 dBm AP at 5° elevation is given as 22 dB, whereas a value of 27 dB has been considered in this study. A 10° downtilt was also considered, however this does not prevent the AP to point above -10° elevation, thus decreasing the available antenna discrimination. That will have to be discussed further once the 5G parameters are available, including further details on the antenna.
• The study is limited to GSO EESS systems, which is indeed one usage of the band for instance for MTG from EUMETSAT. However the case of NGSO EESS and SRS satellites will also have to be addressed.
• The study addresses the single entry case for AP, which is indeed what should be done first. The aggregate interference from a deployment of several AP and UE will then have to also be addressed as well at a later stage.

Although we are still waiting to the final 5G parameters, we have, using similar parameters (but a 20 m antenna height and a 22/29 dB antenna discrimination for the 62/75 dBm AP), conducted our own single entry assessment regarding the Redu 12 m dish earth station tracking NGSO EESS satellites and the Cebreros 35 m dish earth station tracking near Earth SRS missions around Lagrangian points. The preliminary results obtained show a maximum separation distance of 8 km from the EESS earth station in Redu and of 30 km from the more sensitive SRS earth station in Cebreros.

Best regards,

Jean-Yves Guyomard

".

Dear Tuck and James,

Many thanks for the answer. We have calculated the exclusion zones for the Earth stations in Leuk (Switzerland) and Lario (Italy) that will receive data from the GSO MTG satellites from EUMETSAT, that will make use of the 26 GHz band (See attached). Considering a 20m high base station with a 75dBm EIRP and a -29 dB gain towards the horizon we get to a maximum distance of 13 km to be compared with the ~14km that you get (28km/2). When considering a -27 dB antenna discimination we obtain 15km. The results are therefore pretty consistent and do not really change when considering a 10m high antenna.

We continue to perform similar calculations for other earth stations tracking GSO or NGSO EESS and SRS satellites and will put everything on a single paper ASAP.

Best regards, and merry Christmas !

Jean-Yves 

On 16/12/16 15:23 Tuck Poon wrote:
"

Dear Jean-Yves,

Thanks for your comments and apologies for the slow reply. Here's James' comments.

Tuck

----------

Dear Jean-Yves,

Many thanks for taking the time to review our study on 5G compatibility with EESS receiving earth stations. I’ll take each of your comments in order:

• Antenna height – Yes you are right, WP5D’s provisional AP antenna height for suburban is [20m]. Once WP5D has finalised parameters for antenna height (and indeed all other relevant 5G parameters), we intend to update our study. Related to this, we would also need to consider the relevant downtilt according to the height of the 5G antenna.
• Antenna discrimination –  Our value of 27 dB comes from the AP beam boresight pattern (Exhibit B-7 in reference [2]). Because we assume a 16x16 antenna array for both 62 and 75 dBm power configurations, the pattern shows the 10 degree point on the pattern to hit the y-axis at about -15 dB. The boresight gain is at approximately +12 dB, hence an overall relative gain of -27 dB from boresight. For comparison, reference [2] quotes -29 dB relative gain towards the satellite for an angle of 11 degrees (6 degree downtilt + 5 degree elevation to satellite) so -27 dB for 10 degrees would seem about right. Again, once the antenna information is finalised we can update our study.
• NGSO / GSO –  We agree the NGSO case will also need to be studied. The reason we didn’t study it is because there are no known NGSO earth stations in the UK from which to base our parameters on. We are pleased to see that ESA has some preliminary results for the NGSO EESS case, and also for SRS.
• Single entry / aggregate interference – Agreed, the case of aggregate interference from 5G deployments will need to be studied later.

Best Regards,

James Richardson

------------------------------------------------

On 12/12/16 14:00 Jean-Yves Guyomard wrote:
"

Hi Tuck and James,

Many thanks for your studies which are very much appreciated.

If I may, I would like to offer the following comments as ESA on the study related to the exclusion zones around receiving EESS earth stations. I will let AIRBUS comment on the study related to ISS since they are providing the EDRS service to ESA:

• I understand the parameters for 5G will only be available later on next year, however I noticed that the antenna height for AP was taken as 10 m, whereas in [3], it’s provisionally given as 20 m, if I am not mistaking.
• In [2], the antenna discrimination for 62 dBm AP at 5° elevation is given as 22 dB, whereas a value of 27 dB has been considered in this study. A 10° downtilt was also considered, however this does not prevent the AP to point above -10° elevation, thus decreasing the available antenna discrimination. That will have to be discussed further once the 5G parameters are available, including further details on the antenna.
• The study is limited to GSO EESS systems, which is indeed one usage of the band for instance for MTG from EUMETSAT. However the case of NGSO EESS and SRS satellites will also have to be addressed.
• The study addresses the single entry case for AP, which is indeed what should be done first. The aggregate interference from a deployment of several AP and UE will then have to also be addressed as well at a later stage.

Although we are still waiting to the final 5G parameters, we have, using similar parameters (but a 20 m antenna height and a 22/29 dB antenna discrimination for the 62/75 dBm AP), conducted our own single entry assessment regarding the Redu 12 m dish earth station tracking NGSO EESS satellites and the Cebreros 35 m dish earth station tracking near Earth SRS missions around Lagrangian points. The preliminary results obtained show a maximum separation distance of 8 km from the EESS earth station in Redu and of 30 km from the more sensitive SRS earth station in Cebreros.

Best regards,

Jean-Yves Guyomard

".

".

Dear CG Colleagues,

One element of the Terms of Reference of this CG is ”… to review methodology and seek initial views on the modelling of sharing scenarios.”

Writing on behalf of the GSA Spectrum Group (see about GSA at http://gsacom.com/), I’d like to suggest that, as a first step in the work on sharing studies for the 26 GHz band, ECC PT1 should use the new Recommendation ITU-R M.[IMT.MODEL] - Modelling and simulation of IMT networks for use in sharing and compatibility studies ([SG5/ [ 22 ] ]) as the reference method.

GSA would like to note the following advantages of using the new Recommendation ITU-R M.[IMT.MODEL] as a basis  for going forward with the studies on 26 GHz. The new Recommendation ITU-R M.[IMT.MODEL]:

• is applicable to bands both below and above 6 GHz, i.e. it is applicable to modeling of IMT networks in the frequency range considered in this CG
• provides guidance, among other issues, on the implementation of IMT aggregate interference, transmit power control, advanced antenna technologies and traffic load
• will lead to higher spectrum efficiency compared to the traditional MCL method which usually leads to overprotection
• is relatively easy to implement in most simulation platforms including SEAMCAT
• different simulation results could be directly comparable and more easily verified

Best Wishes !

Alessandro Casagni.

Dear Alessandro and CG colleagues,

Happy New Year !

On behalf of SES, we would like to make the following comments.

As you indicated, Rec. ITU-R M.IMT-MODEL is about modelling and simulation of IMT networks for use in sharing and compatibility studies. It is one piece of the puzzle of sharing and compatibility studies. Other pieces include characteristics of incumbent services, propagation models, all the assumptions that are inputs to the studies etc.. Therefore, Rec. ITU-R M.IMT-MODEL is a method to model IMT networks but it is not a methodology as a whole for the studies.

Furthermore, for some sections of Rec. ITU-R M.IMT-MODEL, such as the aggregate IMT interference over a wide area, there might be different ways to actually implement in practice the concept presented. We would therefore be cautious about saying that simulation results can be directly comparable and verified. We will not avoid the exercise of comparing all pieces of the puzzle and all assumptions used to be abe to compare results. 

With regard to "higer spectrum efficiency", we disagree with this bullet. Spectrum efficiency is an intrinsic technical characteristic of a technology or a network. A method to model and simulate IMT networks does not change this intrisinc technical characteristic of IMT. The spectrum efficiency of IMT is not impacted by the way the modeling and simulation of IMT is done.

Best regards,

Cédric Papin

On behalf of SES 

On 24/12/16 10:01 Alessandro Casagni wrote:
"

Dear CG Colleagues,

One element of the Terms of Reference of this CG is ”… to review methodology and seek initial views on the modelling of sharing scenarios.”

Writing on behalf of the GSA Spectrum Group (see about GSA at http://gsacom.com/), I’d like to suggest that, as a first step in the work on sharing studies for the 26 GHz band, ECC PT1 should use the new Recommendation ITU-R M.[IMT.MODEL] - Modelling and simulation of IMT networks for use in sharing and compatibility studies ([SG5/ [ 22 ] ]) as the reference method.

GSA would like to note the following advantages of using the new Recommendation ITU-R M.[IMT.MODEL] as a basis  for going forward with the studies on 26 GHz. The new Recommendation ITU-R M.[IMT.MODEL]:

• is applicable to bands both below and above 6 GHz, i.e. it is applicable to modeling of IMT networks in the frequency range considered in this CG
• provides guidance, among other issues, on the implementation of IMT aggregate interference, transmit power control, advanced antenna technologies and traffic load
• will lead to higher spectrum efficiency compared to the traditional MCL method which usually leads to overprotection
• is relatively easy to implement in most simulation platforms including SEAMCAT
• different simulation results could be directly comparable and more easily verified

Best Wishes !

Alessandro Casagni.

".

All,

Thanks for the inputs and comments to the CG to date.  As a reminder this CG needs to conclude this initial activity by the 6th January.  The CG will then close and I will submit a short report for the forthcoming ECC PT1 meeting.  So far we have the following documents:

-              outline of a working document posted on 29/11/16

-              initial analysis on sharing between IMT2020 and Inter-Satellite Service (ISS) posted 7/12/16

-              initial analysis on sharing between IMT2020 and EESS in the 26 GHz band posted 8/12/16

Best regards,

Robert