Preparatory activities for WRC23 have continued in a number of committees, working groups and workshops in the ITU‑R, CEPT and the European Commission here in Region 1. The developments have been actively supported by the SRLC and the PRC committee chairs with IARU written and verbal contributions. Particular focus continues on the WRC23 AI 9.1b topic on coexistence between the amateur services and radio navigation satellite services (RNSS) in 1240 – 1300 MHz.

During November the CEPT Conference Preparatory Group (CPG) meeting number 4 took place and considered the updates to the CEPT WRC23 Brief on AI9.1b. During this meeting IARU Region 1 took on the role of CEPT co-coordinator for AI9.1b and will continue going forward, sharing the role with France. The CEPT brief will continue to evolve to reflect the studies taking place in ITU‑R WP4C/5A and CEPT SE40 as they reach a stable state.

ITU‑R WP5A also met during November and continued work on the same topic developing the WRC23 Conference Preparatory Meeting Report text (CPM Report) that will summarise the ITU‑R studies required to address the AI9.1b topic at the conference. The meeting started to analyse and consider the study work that continues in WP4C and provided comments regarding the simulation scenarios developed for study. A very early draft ITU‑R Recommendation was proposed which may form the basis for recommending guidance for concerned administrations regarding amateur service coexistence with the RNSS. Work on all these elements will continue into 2022. Click here for the summary report.

In early December CEPT SE40 met and continued the development of their draft ECC report on this issue. This work is now the furthest advanced and IARU has worked hard to ensure the coexistence simulation scenarios properly reflect realistic scenarios for the amateur and amateur satellite services. Simulation work using the ITU‑R propagation model (P.1546) carried out by France and considering the GALILEO system is stabilising and has provided predictions of the interference area around a transmitting amateur station for a range of power levels and station configurations. These simulations have considered typical home based stations used for terrestrial weak signal operating, satellite uplinking, ATV and EME. Repeater station emissions are considered too for both narrowband and ATV operations.

Propagation prediction models are statistical in their nature and assumptions have to be made about terrain and environment. Assuming sub-urban scenarios, 50% of locations and 50% or 1% of time, the following is a sample of the interfered area predictions from the propagation model for a typical 100W home station using a Yagi beam antenna:

Time %	Main Beam distance	Side Lobe radius	Interfered Area
50%	20km	8km	280 km2
1%	25km	10km	440 km2

IARU is continuing to contribute to the discussions to provide additional context around the results of these simulations by considering the real amateur station density and activity factor for a population of 23cm band stations. Click here for the most recent contribution. Click here for a summary report on SE40 Meeting 75.

Finally the European Commission convened a joint EC/CEPT WRC23 workshop covering all the WRC23 agenda items. On AI9.1b, IARU took the opportunity to take the floor and underline the importance of the 23cm band for the amateur microwave community and express the need to find compromises in order to reach mutually acceptable conclusions that can allow the continued development of both services. Click here for the report.

During the period 20 – 26 October 2021, the IARU continued to engage in the preparatory work for WRC-23 agenda item 9.1b in ITU‑R Working Party 4C (WP4C).

The working party is considering simulations provided by two administrations to estimate the interfered area that might exist around a 23cm band amateur service transmitter. A number of amateur station configurations are under consideration identified as “Home Station 1”, “Home Station 2” and “Permanent Station” (e.g. Repeater station) based on characteristics developed and contributed by the IARU. Both narrowband and wideband emissions are considered. Two further scenarios are included in which “Home Station 1” operates with antenna uptilt as an amateur satellite uplink station and in which “Home Station 2” operates with antenna uptilt as an E‑M-E station.

A typical output plot from the simulations looks like this:

The colours represent the varying RNSS received level from high (red) to low (blue) around the transmitter in the centre. The red outline represents a RNSS receiver protection threshold (in this case ‑134.5 dBm)

The IARU representatives contributed to an off-line email discussion to ensure the amateur station parameters used are more representative than those that had been proposed in the original contribution papers. The studies were revised based on these negotiations during the meeting and are reflected in the draft working document. The interim results show interference distances of up to several km depending on the antenna and power level assumed. Work on these studies will continue into the next meeting.

Other measurements campaigns are investigating the effect of offsetting the transmission frequency of various amateur signals with respect to the centre frequency of the RNSS signal and the impact of the RNSS receiver bandwidth.

The IARU is working to ensure the amateur services are realistically represented in the studies as they move forward and remain consistent with the information developed in WP5A. It remains vital that national amateur communities present their views on the importance of this band to their national regulators in a consolidated and consistent manner.

The work on this topic will continue throughout the year both in ITU‑R and in the regional telecommunications organisations and the IARU is committed to ensure every group hears the amateur position on this important microwave band.

The summary report from the WP4C meeting can be found here .

The parallel work in CEPT SE40 is tracking the activity in the ITU‑R and is at a similar stage of development. This is also within the purview of the R1 SRLC.

During the period 5 – 13 July 2021, the preparatory work for WRC-23 agenda item 9.1b continued in ITU‑R Working Party 4C (WP4C). (See Region 1 Feb 23^rd news item for further background). The IARU member representatives from Australia, Brazil, Canada, Germany, Japan, Norway, UK and USA, participated in the meeting and delivered additional information on amateur activities in this key microwave band

Preliminary studies came from France based on the ongoing CEPT work to provide initial estimates of separation distances required between RNSS GALILEO receivers and a sample of amateur emissions. The European Commission GALILEO team provided a set of observations pertaining to a RNSS interference event in northern Italy.

The work contributed by France, although needing refinement, is going in a good direction, using ITU‑R recommended propagation models and assumptions based on operating scenarios provided by the amateur community. Further work is needed to take account of the large disparity between the RNSS service receiver bandwidths and the frequency band offsets of the amateur applications based on the measurements carried out by Germany.

The RNSS community have updated their RNSS receiver protection criteria with an update to ITU‑R Recommendation M.1902 that now includes parameters relevant to the GALILEO E6 signal block. However these criteria only distinguish between a narrow band and wide band interferer level at the receiver and take no account of offset frequency in the receiver bandwidth or any time variance.

The IARU is working to ensure the amateur services are realistically represented in the studies as they move forward. It remains vital that national amateur communities present their views on the importance of this band to their national regulators in a consolidated and consistent manner. The work will continue throughout the year and beyond both in ITU‑R and in the regional telecommunications organisations and the IARU is committed to ensure every group hears the amateur position on this important microwave band.

Click for the summary report from the WP4C meeting.

IARU volunteers have been participating in the CEPT FM and SE Working Groups looking after the amateur and amateur satellite service interests. CEPT WG-SE #88 took place during April and WG-FM #99 took place at the end of May.

WG-FM’s project teams tackle a wide range of civil spectrum applications and are developing important regulatory deliverables relating to wireless power transfer and the 23cm band RNSS coexistence topic amongst other things. Work on both these topics is ongoing. 

The CEPT Radio Amateur Forum Group (RAFG) is hosted by WG-FM and is chaired by the IARU for the time being. Its main task is maintenance of the CEPT Recommendations TR61-01 and TR61-02. A proposal to merge the activities of the RAFG into project team FM58 (Maritime) has been made but the final decision has been held over until the next WG-FM meeting. The RAFG was tasked at this meeting with a new work item to consider the feasibility of developing an electronic database of CEPT wide amateur licensing documentation. This was supported by six administrations.

In WG-SE technical spectrum sharing studies are taking place covering;

• Wireless power transfer including consideration of electric vehicle charging (WPT- EV).
• UWB radiodetermination in 116 – 250 GHz.
• Vehicular radar systems in 77 – 81 GHz.
• Security Scanners in the range 60 — 90 GHz.
• 23cm band RNSS coexistence (related to the WRC item and reported in detail elsewhere).

Amateur service frequency bands are within the scope of all these studies and fall under the remit of the IARU R1 SRLC.

A summary report of the WG-SE meeting is here and the WG-FM meeting is here.

IARU continued engagement in the ITU‑R WRC-23 preparations in the CEPT RTO during May 2021 at the third meeting of the Conference Preparatory Group (CPG). The CPG is the parent group in CEPT that oversees the development of the CEPT Briefs for each of the WRC agenda items and reviews the progress in the individual project teams under the CPG umbrella. IARU provided a contribution putting forward the agreed preliminary IARU positions for these agenda items. IARU’s overall objective is to safeguard the allocations to the Amateur and Amateur-Satellite services in the co and adjacent frequency bands within the scope of each agenda item. The CEPT briefs have a specific section in which the views of all the recognised international and regional organisations can be placed and the IARU views are now in this section of the draft briefs for each of the agenda items of interest.

CPG Project Team	WRC-23 Agenda Items	IARU Interests
PTA	1.12, 1.13, 1.14, 2, 4, 9.1 a), 9.1 c) ‚9.1 d) and 10.	1.12, 1.14 and 9.1 a)
PTB	1.15, 1.16, 1.17, 1.18, 1.19 and 7.	1.18
PTC	1.1, 1.6, 1.7, 1.8, 1.9, 1.10, 1.11 and 9.1 b).	9.1 b)
PTD	1.5.	-
PT1	1.2, 1.3 and 1.4.	1.2

The meeting also heard presentations from other Region 1 RTO’s as well as organisations from R2 and R3 about their own regional preparations. These presentations and the draft CEPT Briefs for each of the agenda items can be found here.

The IARU SRLC continues to be active in all the CEPT project teams dealing with the WRC preparation.

The SRLC Report on the CPG meeting is available here.