Title: ADS - State Table / Protocol Description inconsistency (2nd Issue)

PDR Reference:                    	98100008 
Originator Reference:                                
SARPs Document Reference:        	ADS SARPs, Section 2.2.1.5.3.15.4.2 and 
						Table 2.2.1.5-73
Status:                         	RESOLVED 
Impact:					D (Minor)
PDR Revision Date:               	18/01/99 (PROPOSED -> RESOLVED)
						02/12/98 (ACCEPTED -> PROPOSED)
						29/10/98 (SUBMITTED -> ACCEPTED)
Submitting State/Organization:   	SME2 Team
Submitting Author Name:               	
Submitting Author E-mail Address:            
Submitting Author Supplemental 
Contact Information:                       
SARPs Date:                    	ICAO ATNP Version 2.3 - Doc 9705 Ed. 1
SARPs Language:                 	English

Summary of Defect:

[Note: PDR 98050018 covering this issue was progressed to RESOLVED by CCB-6 (Utrecht). Since then, a new analysis of the problem shows that the agreed solution was not correct. PDR 98050018 is now WITHRAWN and replaced by this PDR.]

Section 2.2.1.5.3.15.4.2 is in conflict with Table 2.2.1.5-73 cell (event=ADS-cancel-contract-PDU,...,ADS-cancel-emergency-ack-PDU, state=LI-G-END).

As illustrated in Figure 2.2.1.5-28 "Crossed air emergency cancellation and cancel all contracts", upon receipt of a D-DATA indication with a ADS-cancel-contract-PDU(emergency), the ADS-ground-ASE is in the state LI-G-END since he has issued a D-END request. The PDU is delivered to the ground EM module. The ground EM module (see 2.2.1.5.3.12.5.1 c and d) creates an ADS-cancel-emergency-ack-PDU and pass it back to the ground LI module. As described by 2.2.1.5.3.15.4.2, the LI module must do nothing (i.e. remain in the LI-G-END state) since he is already waiting for the D-END confirmation.
As a consequence, the situation in 2.2.1.5.3.15.4.2 should be allowed to occur and the corresponding state table cell shall contain the state change instruction "LI-G-END".

Impact on interoperability:				None.

Assigned SME:                                	Sub-Volume II SME

Proposed SARPs amendment: 

Change in Table 2.2.1.5-73 cell (event=ADS-cancel-contract-PDU,...,ADS-cancel-emergency-acknowledgement-PDU, state=LI-G-END) from:

Not permitted

To (<> means text in italics):
<LI-G-END>

SME Recommendation to CCB:   				RESOLVED             	

CCB Decision:                			atnp_ccb_chair: SUBMITTED (14/10/98)
							Atnp_ccb_chair: ACCEPTED (29/10/98)
							atnp_ccb_chair: PROPOSED (08/12/98)
							CCB-8 5honolulu): RESOLVED (18/01/99)