Time And Date - Honeywell ASPIRE-400 System Description, Installation And Maintenance Manual

SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
(1) The ACARS Air-Ground Protocol (AAP) is Inmarsat's bespoke transport layer protocol
used for tunneling of ACARS data over SwiftBroadband network. AAP version 2 defined
in SDM Volume 3 Chapter 4 and in Iris Precursor System Design Document is to be
implemented in the SDU by the Aircraft Data Link Gateway function (ADGW). This
gateway:
(a)
(b)
(c)
(d)
(e)
(2) Terminology aligns to the version2 terminology:
(a)
(3) GDGW Ground Datalink Gateway is equivalent to AGGW ACARS Ground Gateway.
17. Aircraft Information (TASK 23-15-49)
A.

Time and Date

(1) The SDU uses Time and Date for:
(a)
(b)
(c)
(2) On-start up the internal clock is set to a default time and date. Thus, prior to
synchronizing to an external source it only represents a time relative to start up.
(3) The SDU also stores snapshots of the Network Date for:
(a)
(b)
(4) On start-up, the ACD sets its internal time and date to a default of 2016-01-01, 0 hours, 0
minutes, 0 seconds.
(5) The ACD prohibits timestamping and logs "aging out operations using absolute time and
date until the internal time and date has synchronized with either aircraft or network time
and date.
(6) The ACD synchronizes its internal time and date to the first source that provides it:
(a)
(b)
(7) Once the ACD has selected a source and synchronized its internal time and date to that
source, the ACD continues to synchronize its internal time and date to that source until
the next SDU restart.
(8) The ACD distributes its internal time and date to the AP Processor at minimum at startup
or when a resynchronization occurs.
EFFECTIVITY
ALL
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ASPIRE-400
Requires VPN authentication by the underlying Air Security Gateway function
(ASGW) and the related security smart card.
Provides for connection of ACARS services.
Provides Location tracking services.
Provides time-stamping required for the mandatory service performance
monitoring at the service provider level.
Provides independent link availability monitoring (keep-alives).
ADGW Aircraft Datalink Gateway is equivalent to AAGW ACARS aircraft
Gateway.
Timestamping messages to the CFDS
Timestamping log entries
Assessing validity of PIMBIT test frequencies.
Assessing validity of PIMBIT test frequencies
Checking expiration of temporary license keys.
The ORT identified time and date source, OR
Time received from the Inmarsat satellite SBB system information.
23-15-49
3rd rvw Draft as of:
29 January, 2020
Page 2-41
22 Apr 2019