The 86th meeting of SE24 was held in Mainz, Germany
(7-9 December 2015).
SE 24 received the results of public consultation of two ECC Reports:
- ECC Report 244, in response to WI 52 on the compatibility of Radio Local Area Networks (RLANs) with other services in the band 5725-5925 MHz
- ECC Report 246, in response to WI 54 on SRDs with duty cycle up to 2.5% in the band 870-875.6 MHz.
Comments to the public consultation of both reports were received according to the deadline, set on the 2nd of December 2015.
While comments on ECC Report 244 could easily be resolved, this was not the case with regards to ECC Report 246, where further discussions are needed.
SE 24 has continues its work on several draft ECC Reports in response to different work items. Two further draft reports within the scope of WI 49 and WI 55 were also finalised. Work is still ongoing with respect to WI 42 (related to WI54), WI 44, WI 51 and WI 52.
SE24 has made progress on the following items:
WI SE24_52: Compatibility studies on RLANs in the band 5725 - 5925 MHz
The meeting dealt with the comments received during the public consultation of ECC Report 244 (part 1 report). Basically, only comments from Ericsson and the Russian Federation were received and could easily be resolved. The report is now ready for final approval at WG SE level.
Work on the part 2 report continued at this meeting with input contributions from WiFi Alliance, SES and Ericsson / Qualcomm. So far, no feedback was received from TC BRAN on the three work items (TR 103 317, TR 103 318, TR 103 319), but an updated from TC BRAN maybe expected after their next meeting (14-18 December 2015). The meeting included all the information provided so far and cleaned the report, adding some editor’s note for further work. Therefore, the draft report (2nd part) couldn’t be finalized at this meeting, but it contains a good basis for further work.
This second report contains placeholders for the open issues left from ECC Report 244 together with the consideration of mitigation techniques that may allow compatibility with incumbent services in the bands within the scope of the report.
The report also includes some elements that will have to be considered further during the course of future studies. Currently the following topics are proposed for further study:
• Considerations of the impact of LAA-LTE characteristics and deployment scenarios on sharing and compatibility studies between RLAN and incumbent services and applications in the 5350 – 5470 MHz and 5725 – 5925 MHz bands.
• Recognition of the status of previous studies dealing with:
o Sharing and compatibility with the EESS (active) in the band 5350-5470 MHz
o Sharing and compatibility with the Radiolocation Service in the bands 5350-5470 MHz and 5725-5850 MHz
o Sharing and compatibility with other services and systems in the bands 5725-5850 MHz and 5850-5925 MHz
o Compilation of technical information on RLAN mitigation techniques that could facilitate sharing
• Further assessment of the methodology set out in ECC Report 244 and previous studies looking to estimate and predict aggregate interference from RLAN deployments and its effect on possible future sharing and compatibility scenarios between RLAN and incumbent services and applications in the 5350 – 5470 MHz and 5725 – 5925 MHz bands.
• Setting out the methodologies for possible measurement campaigns that may help provide more evidence to assess and validate assumptions made with respect to modelling of interference from future RLAN deployments.
At this stage, the second report is still in a draft status and there are still a number of open issues to be further discussed on the topics mentioned above and the possible mitigation techniques that could be implemented to facilitate sharing between RLAN and incumbent services and applications.
The next steps of this work needs to be discussed at the next WGSE/WGFM/ECC meetings in light of the latest developments at ITU level (see doc 161). Therefore SE24 prepared a draft LS that should be send from WGSE to WGFM (Annex 6).
WI SE24_54: SRDs with duty cycle up to 2.5% in the band 870-875.6 MHz .
The outcome of this WI, i.e. ECC Report 246 was under public consultation until 2nd of December 2015.
The meeting discussed the comments provided during the public consultation in three sessions chaired by the SE24 chairman.
It was possible to resolve a few comments (RFID vs CSMA, selectivity), but other comments could not be resolved:
- Mobile operators suggested approving the report but adding a sentence that further work is needed to determine the required mitigation measures for the protection of public cellular system below 915 MHz.
- The UK industry group and OFCOM UK is concerned that theprotection criteria for cellular systems in adjacent bands are too conservative, and they suggested to postpone the approval of the report
A long debate started on the pros and cons of further studies.
Advantages of further studies:
- The main advantage to postpone the adoption is due to similarities with WI42, where for similar scenarios (adjacent band public cellular systems below 862 and below 915 MHz) different assumptions were adopted in the meanwhile (receiver selectivity, …) and where further changes are expected.
- Thus the reports on WI54 and WI42 could be delivered in a package to WGSE next year and the same assumptions could be used in both reports.
- The concerned parties will get more time
Disadvantages of further studies:
- The studies draft ECC report 246 are based on the published ECC Report 200, where similar discussions on adjacent band studies took place. It is questionable if the continuation of the studies will in the end lead to other results as in the current version of draft ECC Report 246.
- It is not totally clear what the concerned parties are aiming to do to get better results
- Some people spend a lot of time to run simulations and to support this activity and there is a risk that all work will needs to be done again
- Even if the new studies will show that a smaller or no guard band is needed for the protection of public cellular systems (currently suggested is a 800 kHz guard band), then WB SRDs can’t use 6 non-overlapping 1 MHz channels, since safe harbour bands are already established at the band edge 915-915.2 MHz, and therefore is would not make any difference for the WB SRD systems
There were opposed views on how to proceed regarding the approval of the draft ECC Report 246 and how to deal with the comments received during the public consultation. Specifically, Ericsson was concerned about delaying the approval of the report, as in their view there is a lack of understanding of the way cellular networks are modelled and operated from the SRD side. On the other hand, there were views expressed that new simulations should be performed in order to cover points raised by the SRD industry in order to be able to approve the report.
The meeting decided that Wi54 should be set on-hold and the focus should be now on WI42 until agreement is achieved for adjacent band studies. Then the adjacent band studies for WI54 can adopt the WI42 approach.
The Intra –SRD studies can be seen as finalised now and if possible should not be touched again. The only change in the intra SRD section is that a few simulations should be provided for the real receiver selectivity mask adopted for WI42. But the consistency between the intra SRD and adjacent band studies should be kept.
Since the SE24 chairman, Mr. Ralf Kallenborn, took care about this work item the last months but he will no longer participate in SE24 after January 2016, there was a need to appoint a rapporteur. The meeting agreed with Mr. Enrico Tosato as new rapporteur.
WI SE24_42: Improvements for SRDs in the 862-870 MHz :
SE24 was not able to consider all the contributions received, but made some progress on this WI.
A LS to STG was drafted during the meeting (and further discussed through e-mail) proposing a few improvements to SEAMCAT. It should be noted that SE24 do not need to wait for the implementation of those points in SEAMCAT to continue its work.
Since the SE24 chairman, Mr. Ralf Kallenborn, took care about this work item the last months but he will no longer participate in SE24 after January 2016, there was a need to appoint a rapporteur. The meeting agreed with Mr. Enrico Tosato as new rapporteur.
WI SE24_49 :TTT/DSRC in the 5805-5815 MHz band :
The draft report was finalized at the meeting and will be sent to WG SE for provisional approval.
WI SE24_55 :Impact of UWB applications on board aircraft in the band 6-8.5 GHz on FS links used around airports :
The draft ECC Report on “The impact of UWB applications on board aircraft in the band 6-8.5 GHz on FS links used around airports and on EESS earth stations” was discussed before this meeting in a Webmeeting (2015-11-19) chaired by Mr. Rune Bøe.
SE24 noted that the relevant stakeholders from the FS- (Telenor) and EESS- (ESA) communities were deeply involved in the development of the latest draft and agreed, that there is no issue with UWB on board aircraft. Accordingly the draft ECC report provided no controversial material and is in a good shape and very stable.
Accordingly, SE24 agreed to approve the draft ECC report to be sent to WGSE for provisional approval.
Other items:
- WI SE24_44 : New bands for Assistive Listening Devices (ALD) :
There was no input at this meeting.
- WI SE24_51 :Fixed infrastructure radars in the band 76-77 GHz :
SE 24 will continue the work on this WI with the aim to be sent to the September 2016 meeting of WG SE for provisional approval.
Other issues:
SE 24 WI 56: Studies in the band 1900-1920 MHz (BB DA2GC – DECT/SRDs):
During its last meeting WGSE agreed on a new work item for SE24, but SE24 should not start before December 2015, due to ongoing discussions at RSC and ECC level on the future of the band 1900-1920 MHz. For this meeting an update from RSC was available from the SE24 chairman. SE24 believes that at this stage new studies are not meaningful. Also, during the joint SE24 / SRD-MG session, SRD/MG chairman confirmed that the work item is no longer needed.
Ralf Kallenborn (SE 24 chairman) said goodbye to the group, as it was his last meeting. He kindly organised a social event (a dinner in a typical restaurant in Mainz). On their turn, the group thanked Ralf for his excellent work and wished him all the best in his future responsibilities by offering him some farewell presents.
Next meetings:
- M87, 29 February to 2 March 2016, Ljubljana, Slovenia.
- M88, 18-20 April 2016, Vilnius, Lithuania
- M89, 5-7 September 2016, London, United Kingdom
- M90, [28-30 November 2016], Mainz, Germany
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