Dear Šarūnas,
I am coming back to you regarding your questions on the purpose of the ECC Recommendation.
This ECC recommendation is intended to identify a limited set of NR frame structures in border areas in order to facilitate cross-border agreements.
As you mentionned, the proposed frame B, is a NR frame structure compatible with LTE frame n°2. The LTE frame structure n°2 is the configuration commonly deployed. In order to clarify this point, I would like to suggest an additional considering :
That the NR Frame B given in annex 1 is compatible with the LTE frame structure configuration n°2, DSUDDDSUDD (10ms periodicity), where different special subframe, “S” are possible such as SS n°6, 9:3:2 or SS n°7, 10:2:2 (number symbols Downlink:Guard Period:Uplink)
Regarding the choice of the Frame A, the NR frame DDDSUDDDSU seems to be the main “pure” NR frame structure identified within CEPT.
In addition to that, the limitation of these two NR frame structures A and B in border areas will help to create the eco system needed for the development of technical features such as DL symbol blanking.
Dear Michael,
Many Thanks for your proposed amendments and your additional document on C-Band Cross-Border Coordination in UK.
Regarding your proposal to consider another frame C, which is similar to the Frame B in the draft ECC Recommendation with a different slot S. I would like to suggest the following considering in order to adress your point, regarding the usage of the same frame with a different guard period
- that ECC report 216 states that "synchronised operation implies configuring compatible frame structures, i.e. setting the length of the frame, the TDD uplink/downlink ratio and guard period in order to align UL/DL switching points, so that the last transmitter stops before the first receiver starts, taking into account the propagation delay (e.g. in LOS non co-sited cases). Frame structures do not need to be exactly identical provided this condition is met", which enables different sizes for the guard period.
In addition to that, there is an additional row and note n°5 in the table for the NR frame B to cover the special slot S 4 6 4.
We are intented to identify a limited number of NR frame structures in border areas but not limiting the flexibility for administrations for the national case, for this reason, I did not maintained the suggested Frame D which allow a lot of possibilities and increase the difficulty to find solution in border areas. The following considering define a cross-border coordination area:
- that in order to develop crossborder coordination agreement, there is a need to identify a proper coordination area in case different frame structures are chosen across the border
As the annex 1 proposed two NR frame structures, I suggest to maintain the reference to subcarrier spacing.
Thanks to you Sarunas, Michael, Tobias and Didier for the proposed amendments.
Dear all,
You wil find in attach a revision of the draft ECC Recommendation, the amendments are underligned in green.
Kind Regards,
Keite Dyvrande