1. Bernard KORSEC113-15 MAR 2007 ICAO 24-BIT ADDRESS (Mode S code) ICAO – ACP – WGM – 8th MEETING OF THE IRIDIUM SUBGROUP 13 – 15 MAR 2007

2. Bernard KORSEC213-15 MAR 2007 ICAO – ACP – WGM – 8th MEETING OF THE IRIDIUM SUBGROUP 13 – 15 MAR 2007 SEVERAL POSSIBILITIES EXIST From the ATC Mode S Transponders, the ARINC 429 Labels 275 and 276 provide the « ICAO 24-bit Address ». (ARINC Characteristic 761, Page 31, Attachment 1-4, Paragraph 3 « ICAO 24-bit aircraft address »). A CM (Configuration Module) mounted externally to the SDU (Satcom Data Unit). REMARKS An ARINC Characteristic for IRIDIUM Satcom, based on the existing « 761 » maybe helpful for SDU manufacturers and operators, knowing that the airplane manufacturers already designed and have sometimes provisioned airplanes for the « ARINC Characteristic 761 ». This will make easy any retrofit to the IRIDIUM System concerning the interfaces between airplane and IRIDIUM SDU.

3. Bernard KORSEC313-15 MAR 2007 ICAO – ACP – WGM – 8th MEETING OF THE IRIDIUM SUBGROUP 13 – 15 MAR 2007 SUGGESTION: Concerning the ICAO 24-bit Address and the telephone number. Considering the following ICAO 24-bit address in octal coding: 76543210 Why not having the ICAO 24-bit address part of the phone number with a prefix indicating that the present phone number contains an ICAO 24-bit address: 8816 X76 543 210 (X indicating a telephone number including an ICAO 24-bit Address - To be defined by IRIDIUM) No mapping required From AES to GES: only the first five digits to be removed before forwarding the message into the ATN. From GES to AES: only the first five digits to be added by IRIDIUM before forwarding the message to the airplane.