Title: DFIS - ASN.1 Version 1 Retrofit

PDR Reference:              		M1030001
Originator Reference:            	M103000x
SARPs Document Reference:         	DFIS, Section 2.4.4.2
Status:                       	ADOPTED
Impact:					A (FIS)
PDR Revision Date:              	30/01/02 (RESOLVED -> ADOPTED)
						07/03/01 (PROPOSED -> RESOLVED)
						05/03/01 (ACCEPTED -> PROPOSED, asn file 
						added (M1030001.asn.txt), SARPs amendment 
						section added
						01/03/01 (SUBMITTED -> ACCEPTED)
PDR Submission Date:           	01/03/01 (SUBMITTED)
Submitting State/Organization:    	ATNP/WGA
Submitting Author Name:          	Picard, F 
Submitting Author E-mail Address:  	picard_frederic@stna.dgac.fr
Submitting Author Supplemental 
Contact Information:               	tel. +33.5.62.14.55.33
						fax. +33.5.62.14.54.01
SARPs Date:                      	Doc 9705 Edition 2
						Doc 9705 Draft Ed 3 
SARPs Language:                  	English

Summary of Defect:

Since the ASN.1 description of the D-ATIS report is not aligned in DFIS Version 1 with the current ICAO documentation (Annex 3 and Doc 9694), DFIS version 1 will never be put into operation by ATS Organisations. The version 1 related material shall therefore be withdrawn from Annex 10 and Doc 9705.

WGA decided at its second meeting in Honolulu (March 2001) to replace the Version 1 ASN.1 by the Version 2 ASN.1 (D-ATIS fields only).  This is possible because there is no known operational implementation. In addition, this makes version 2 and version 1 interoperable, when D-ATIS is operated without security. 

Assigned SME:                    	Sub-Volume II SME

Proposed SARPs amendment: 

1/ Change note to section 2.4.2.1 from:
Versions 1 and 2 are not backwards compatible 

To:
Versions 1 and 2 are backwards compatible.

2/ Change note to section 2.4.4.2.1 from:
The structure, range and resolution of some meteorological parameters in this section are not fully in line with provisions of Annex 3 (up to and including Amendment 72). 

To:
The message set for the D-ATIS service defined in this section is aligned with ICAO Annex 3 (Meteorological Service for International Air Navigation) 13th Edition (up to and including Amendment 72) and consistent with DOC 9694 (Manual of Air Traffic Services Data Link Applications) 2nd Edition.

3/ Change the complete ASN.1 for version 1 in 2.4.4.2.1 by the ASN.1 contained in file M1010001.asn.txt attached to this PDR.

Proposed GM amendment: The sections related to the version 1 / Version 2 interoperability must be reviewed.

P/OICS amendment: The sections of version 1 should be modified on the basis of version 2 sections.

Impact on interoperability:	interoperability between "new" version 1 (resulting of this PDR) and "old" version 1 is not possible. Interoperability between "new" version 1 and version 2 is now provided. 		

PDR Validation Status:			ASN.1 compilation using an independant tool.

SME Recommendation to CCB: 		

CCB Decision:                    	SGA2/02 (Honolulu): SUBMITTED (28/02/01)
						CCB-13/1 (Honolulu): PROPOSED (05/03/01) 
						CCB-13/2 (Honolulu): RESOLVED (07/03/01)