Technical Provisions for Mode S Services and Extended Squitter

A-80 Technical Provisions for Mode S Services and Extended Squitter
MB FIELD
DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris
Table A-2-97. BDS code 6,1 — Extended squitter emergency/priority status
1
2
MSB PURPOSE: To provide additional information on aircraft status.
3 FORMAT TYPE CODE = 28
4 Subtype shall be coded as follows:
5 LSB
6 MSB 0 = No information
7 SUBTYPE CODE = 1 1 = Emergency/priority status
8 LSB 2 to 7 = Reserved
9 MSB
10 EMERGENCY STATE
11
12
LSB Emergency state shall be coded as follows:
13 Value Meaning
14 0 No emergency
15 1 General emergency
16 2 Lifeguard/Medical
17 3 Minimum fuel
18 4 No communications
19 5 Unlawful interference
20 6 Reserved
21
22
7 Reserved
23
1) Message delivery shall be accomplished once per 0.8 seconds using
24
the event-driven protocol.
25
26
27
2) Termination of emergency state shall be detected by coding in the
surveillance status field of the airborne position message.
28
29
3) Emergency State value 1 shall be set when Mode A code 7700 is
provided to the transponder.
30
4) Emergency State value 4 shall be set when Mode A code 7600 is
31
provided to the transponder.
32
33
34 RESERVED
5) Emergency State value 5 shall be set when Mode A code 7500 is
provided to the transponder.
35
Note.—The data in this register is not intended for extraction using
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
GICB or ACAS cross-link protocols. The read out of this register is
discouraged since the contents are indeterminate.
Draft
DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris