Over the peri­od 9th to 19th May 2023, the prepara­to­ry work for WRC-23 agen­da item 9.1b con­tin­ued in ITU‑R Work­ing Par­ty 5A (WP5A). Two deliv­er­ables are under discussion:

1) Draft ITU‑R Report M.[AMATEUR_CHARACTERISTICS] – this reports on the spe­cif­ic 23cm band ama­teur and ama­teur satel­lite ser­vice tech­ni­cal para­me­ters and oper­a­tional char­ac­ter­is­tics used in the stud­ies now pub­lished in ITU‑R Report M.2513–0.

2) Draft ITU‑R Rec­om­men­da­tion M.[AS_GUIDANCE] – this will rec­om­mend guid­ance that nation­al admin­is­tra­tions can take to facil­i­tate the pro­tec­tion of the radio nav­i­ga­tion satel­lite ser­vice from harm­ful inter­fer­ence from ama­teur radio stations.

Ahead of this WP5A meet­ing the IARU glob­al WRC-23 9.1b team led by G4SJH devel­oped and sub­mit­ted two con­tri­bu­tions, one for each deliv­er­able above.  As usu­al, the IARU par­tic­i­pat­ed in the meet­ing to present the con­tri­bu­tions and take part in the ongo­ing dis­cus­sion and nego­ti­a­tions. The IARU con­tri­bu­tion to the Guid­ance rec­om­men­da­tion pro­posed spe­cif­ic lim­its for EME oper­a­tion in the range 1296 – 1300 MHz. The pro­pos­al was large­ly adopt­ed but only in the range 1298 – 1300 MHz. The IARU con­tri­bu­tion to the “char­ac­ter­is­tics” report  pro­posed an annex con­tain­ing a Monte Car­lo style study assess­ing the impact of a range of ama­teur trans­mis­sions on a pop­u­la­tion of RNSS receivers around the ama­teur sta­tion. Con­tri­bu­tions were also pro­vid­ed by a num­ber of nation­al admin­is­tra­tions and a sum­ma­ry report of the meet­ing can be down­loaded here.

The devel­op­ment of the rec­om­men­da­tion is prov­ing chal­leng­ing although many of the IARU pro­pos­als remain in the draft doc­u­ment for fur­ther dis­cus­sion. Chal­lenges are aris­ing from oth­er pro­pos­als that could be judged to go beyond the orig­i­nal man­date for the work. In addi­tion some pro­pos­als for tech­ni­cal and oper­a­tional mea­sures seem imprac­ti­cal from both an admin­is­tra­tion and ama­teur sta­tion perspective.

The study pro­posed for the char­ac­ter­is­tics report was accept­ed for now but is to be liaised to WP4C for con­sid­er­a­tion and pos­si­ble revi­sion to Report ITU‑R M.2513.

Mean­while in CEPT the work in project team SE40 con­tin­ued dur­ing the same peri­od (15 – 17^th May) with their devel­op­ment of an ECC Report on the same coex­is­tence prob­lem. IARU con­tributed the same Monte Car­lo study to that group where it now sits in the draft deliverable.

In ITU_R the work on this top­ic will con­tin­ue at the next ITU‑R WP5A meet­ing in Sep­tem­ber with some urgency to finalise both deliv­er­ables ahead of the WRC.