Title: FIS - Positive Acknowledgement on a negative contract-update response 

PDR Reference:				97100023
Originator Reference: 			updatereject
SARPs Document Reference: 		FIS SARPs, all sections
Status: 					ADOPTED
PDR Revision Date: 			20/10/97 (SUBMITTED -> ACCEPTED)
						29/10/97 (ACCEPTED -> PROPOSED -> RESOLVED)
PDR Submission Date:  			06/10/97
Submitting State/Organization: 	ATNP WG3/SG2
Submitting Author Name: 		Picard, F
Submitting Author E-mail Address: 	picard_frederic@stna.dgac.fr
Submitting Author Supplemental 
Contact Information:			ph 33 (0)5 62 14 55 33,
						fx 33 (0)5 62 14 54 01
SARPs Date:  				IV1.1, March 97
SARPs Language: 				English

Summary of Defect:  

The ADSP Manual states that upon receipt of an update contract indication, in case it does not support the contract mode and the requested FIS information is not available immediately, the FIS ground system shall be able: 
a) to send a positive acknowledgement to the aircraft first,
b) and when the FIS information becomes available to uplink the update contract rejection with the FIS information.

The current SARPs does not allow the ground system to send a positive acknowledgement in the case of a contract rejection. The positive acknowledgement is always associated with the acceptance of the contract. The ground system shall immediately uplink the update contract rejection along with, if available, the FIS information.

Assigned SME: 				Sub-Volume II SME

Proposed SARPs amendment: 

In chapter 1 INTRODUCTION, the functional description of the FIS Update Contract shall be modified.

In chapter 2 THE ABSTRACT SERVICE, the authorised values for the Result parameter of the FIS-update-contract response should be "accepted", "accepted with positive acknowledgement", "rejected" and "rejected with positive acknowledgement". Everywhere in the document, "positive acknowledgement" shall be changed to "accepted with positive acknowledgement". 

In chapter 4 FORMAL DEFINITION OF MESSAGES, the PDU indicating the rejection of the update contract shall be modified to include a new value "positive acknowledgement".

In chapter 5 PROTOCOL DEFINITION, two new figures shall be added to show how the update contract can be rejected with a positive acknowledgement. 
* A new requirement on the FIS-ground-ASE shall be added upon receipt of a FIS-update-contract response with a result parameter containing the abstract value "rejected with positive acknowledgement" (see 2.4.5.3.8.4).
* The requirement 2.4.5.3.7.5 on the FIS-air-ASE "Upon receipt of a [FISReject] APDU" shall applied when the FISReject APDU contains the value "rejected". 
* A new requirement on the FIS-air-ASE shall be defined for the case where the FISReject APDU contains the value "rejected with positive acknowledgement". A new state UC-A-NEGATIVE shall be created.
* A new requirement on the FIS-air-ASE shall be added for the case the [FISReport] APDU is received and the ASE is in the state UC-A-NEGATIVE. The ASE shall start the t-inactivity timer and deliver a FIS-report to the FIS-air-user.
* The state tables shall be modified accordingly.

In chapter 7 USER REQUIREMENTS, new requirements shall be defined on both FIS-users.

SME Recommendation to CCB: 		RESOLVED

The modifications listed above required by this PDR impact too much the current specifications of the FIS protocol to be included in version 1. It is propose to postpone the modification to version 2. However, in order to allow the modification of the ASN.1 type FISRejectData in version 2 (e.g. new value "updateFunctionNotSupportedWithPosAck"), an extensibility marker shall be added in the ASN.1 definition of this type as follows:

FISRejectData ::= CHOICE
	{
	 updateFunctionNotSupported			[0] NULL,
	 updateFunctionNotSupportedWithReport	[1] FISReportData,
	 otherReasons					[2] FISRejectReason,
	 ...
	}

CCB Decision:				atnp_ccb_chair: ACCEPTED (20/10/97)
						CCB-3: RESOLVED
						The problem shall be forwarded to WG3