Asterix category 023 - CNS/ATM Ground Station and Service Status Reports
category: 023
edition: 1.2
date: 2009-03-01
Preamble
Surveillance data exchange.
Description of standard data items
I023/000 - Report Type
Definition: This Data Item allows for a more convenient handling of the reports at the receiver side by further defining the type of transaction.
Structure:
8 bits [
........
]values:
1: Ground station status report
2: Service status report
3: Service statistics report
- NOTES:
-
- In applications where transactions of various types are exchanged, the Report Type Data Item facilitates the proper report handling at the receiver side.
- All Report Type values are reserved for common standard use.
I023/010 - Data Source Identifier
Definition: Identification of the Ground Station from which the data is received.
Structure:
I023/010/SAC - System Area Code
- 8 bits [
........
]- raw value
I023/010/SIC - System Identification Code
- 8 bits [
........
]- raw value
- Note:
-
- The up-to-date list of SACs is published on the EUROCONTROL Web Site (http://www.eurocontrol.int/asterix).
I023/015 - Service Type and Identification
Definition: Identifies the type of service being reported.
Structure:
I023/015/SID - Service Identification
- 4 bits [
....
]- raw value
I023/015/STYP - Type of Service
4 bits [
....
]values:
1: ADS-B VDL4
2: ADS-B Ext Squitter
3: ADS-B UAT
4: TIS-B VDL4
5: TIS-B Ext Squitter
6: TIS-B UAT
7: FIS-B VDL4
8: GRAS VDL4
9: MLT
- Note:
-
- The service identification is allocated by the system.
- The service identification is also available in item I021/015.
I023/070 - Time of Day
Definition: Absolute time stamping expressed as UTC time.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
Notes:
- The time of day value is reset to zero each day at midnight.
I023/100 - Ground Station Status
Definition: Information concerning the status of a Ground Station.
Structure:
Extended item.
I023/100/NOGO - Operational Release Status of the Data
1 bit [
.
]values:
0: Data is released for operational use
1: Data must not be used operationallyI023/100/ODP - Data Processor Overload Indicator
1 bit [
.
]values:
0: Default, no overload
1: Overload in DPI023/100/OXT - Ground Interface Data Communications Overload
1 bit [
.
]values:
0: Default, no overload
1: Overload in transmission subsystemI023/100/MSC - Monitoring System Connected Status
1 bit [
.
]values:
0: Monitoring system not connected or unknown
1: Monitoring system connectedI023/100/TSV - Time Source Validity
1 bit [
.
]values:
0: Valid
1: InvalidI023/100/SPO - Indication of Spoofing Attack
1 bit [
.
]values:
0: No spoofing detected
1: Potential spoofing attackI023/100/RN - Renumbering Indication for Track ID
1 bit [
.
]values:
0: Default
1: Track numbering has restarted
(FX)
extension bit
0: End of data item
1: Extension into next extentI023/100/GSSP - Ground Station Status Reporting Period
- 7 bits [
.......
]- unsigned quantity
- unit: “s”
- LSB = 1 s
- value > = 1 s
- value < = 127 s
(FX)
extension bit
0: End of data item
1: Extension into next extent
Notes:
- A time source is considered as valid when either externally synchronised or running on a local oscillator within the required accuracy of UTC.
- Bit 8 (NOGO), when set to “1” indicates that the data transmitted by the GS is not released for operational use.
- Bit 2 indicates that the allocation of Track-IDs (Item I021/161) was re-started.
I023/101 - Service Configuration
Definition: Information concerning the configuration of a Service.
Structure:
Extended item.
I023/101/RP - Report Period for Category 021 Reports
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/2 s ≈ 0.50 s
I023/101/SC - Service Class
3 bits [
...
]values:
0: No information
1: NRA class
2: Reserved for future use
3: Reserved for future use
4: Reserved for future use
5: Reserved for future use
6: Reserved for future use
7: Reserved for future useI023/101/(spare)
- 4 bits [
....
]
(FX)
extension bit
0: End of data item
1: Extension into next extentI023/101/SSRP - Service Status Reporting Period
- 7 bits [
.......
]- unsigned quantity
- unit: “s”
- LSB = 1 s
- value > = 1 s
- value < = 127 s
(FX)
extension bit
0: End of data item
1: Extension into next extent
I023/110 - Service Status
Definition: Information concerning the status of the Service provided by a Ground Station.
Structure:
Extended item.
I023/110/(spare)
- 4 bits [
....
]I023/110/STAT - Status of the Service
3 bits [
...
]values:
0: Unknown
1: Failed
2: Disabled
3: Degraded
4: Normal
5: Initialisation
(FX)
extension bit
0: End of data item
1: Extension into next extent
I023/120 - Service Statistics
Definition: Statistics concerning the service. Provides counts of various ADS-B message types that have been received since the report was last sent.
Structure:
Repetitive item, repetition factor 8 bits.
I023/120/TYPE - Type of Report Counter
8 bits [
........
]values:
0: Number of unknown messages received
1: Number of too old messages received
2: Number of failed message conversions
3: Total Number of messages received
4: Total Number of messages transmitted
20: Number of TIS-B management messages received
21: Number of Basic messages received
22: Number of High Dynamic messages received
23: Number of Full Position messages received
24: Number of Basic Ground messages received
25: Number of TCP messages received
26: Number of UTC time messages received
27: Number of Data messages received
28: Number of High Resolution messages received
29: Number of Aircraft Target Airborne messages received
30: Number of Aircraft Target Ground messages received
31: Number of Ground Vehicle Target messages received
32: Number of 2 slots TCP messages receivedI023/120/REF - Reference from which the Messages Are Countered
1 bit [
.
]values:
0: From midnight
1: From the last reportI023/120/(spare)
- 7 bits [
.......
]I023/120/CV - 32-bit Counter Value
- 32 bits [
................................
]- raw value
I023/200 - Operational Range
Definition: Currently active operational range of the Ground Station.
Structure:
- 8 bits [
........
] - unsigned quantity
- unit: “NM”
- LSB = 1 NM
Notes:
- Maximum value indicates “maximum value or above”.
I023/RE - Reserved Expansion Field
Definition: Expansion
Structure:
Explicit item (RE)
I023/SP - Special Purpose Field
Definition: Special Purpose Field
Structure:
Explicit item (SP)
User Application Profile for Category 023
I023/010
- Data Source Identifier
I023/000
- Report Type
I023/015
- Service Type and Identification
I023/070
- Time of Day
I023/100
- Ground Station Status
I023/101
- Service Configuration
I023/200
- Operational Range
(FX)
- Field extension indicatorI023/110
- Service Status
I023/120
- Service Statistics
(spare)
(spare)
(spare)
I023/RE
- Reserved Expansion Field
I023/SP
- Special Purpose Field
(FX)
- Field extension indicator