CPDLC in UK Airspace

[szpajder]

Thread resurrection time...

Decoding of CPDLC and ICAO Context Management protocol is supported in dumpvdl2 version 1.1.0.

Download here: https://github.com/szpajder/dumpvdl2/releases

The output format is currently a bit crude, it's just a raw dump of the decoded ASN.1 payload. Pretty-printing of CPDLC will be implemented in subsequent releases.

A few examples:

Logon to CPDLC service:

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[2017-05-21 19:32:06 CEST] [136.975] [-20.6/-45.0 dBFS] [24.4 dB]
502C54 (Aircraft, Airborne) -> 2B86F7 (Ground station): Command
AVLC type: I sseq: 0 rseq: 3 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 7 rseq: 7 more: 0
CLNP PDU, compressed header:
COTP Data:
cmLogonRequest: CMLogonRequest ::= {
    aircraftFlightIdentification: BTI2UK
    cMLongTSAP: LongTsap ::= {
        rDP: 41 42 54 49 00
        shortTsap: ShortTsap ::= {
            aRS: 50 2C 54
            locSysNselTsel: 00 00 00 00 00 00 00 00 01 01
        }
    }
    groundInitiatedApplications: groundInitiatedApplications ::= {
        AEQualifierVersionAddress ::= {
            aeQualifier: 22
            apVersion: 1
            apAddress: longTsap: LongTsap ::= {
                rDP: 41 42 54 49 00
                shortTsap: ShortTsap ::= {
                    aRS: 50 2C 54
                    locSysNselTsel: 00 00 00 00 00 00 00 00 01 02
                }
            }
        }
    }
    airportDeparture: EETN
    airportDestination: LOWW
    dateTimeDepartureETD: DateTime ::= {
        date: Date ::= {
            year: 2017
            month: 5
            day: 21
        }
        time: Time ::= {
            hours: 16
            minutes: 17
        }
    }
}


Initial welcome message from ACC Praha:

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2B86F7 (Ground station, On ground) -> 3C6678 (Aircraft): Command
AVLC type: I sseq: 1 rseq: 6 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 2 rseq: 1 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 19 63 30 2a e8 65 52 84 cc 00 2d c9 e1 d5 a5 4a 2c ea 88 20 d4 86 82 ac e9 35 10 4c 97 06 0a ca 14 a0 c8 82 82 94 18 90 69 2c 87 16 75 48 b4 88 15 90
c2 83 40
ATCUplinkMessage ::= {
    header: ATCMessageHeader ::= {
        messageIdNumber: 3
        dateTime: DateTimeGroup ::= {
            date: Date ::= {
                year: 2017
                month: 5
                day: 21
            }
            timehhmmss: Timehhmmss ::= {
                hoursminutes: Time ::= {
                    hours: 4
                    minutes: 51
                }
                seconds: 0
            }
        }
        logicalAck: 0
    }
    messageData: ATCUplinkMessageData ::= {
        elementIds: elementIds ::= {
            uM183FreeText: CURRENT ATC UNIT LKAA,PRAHA RADAR,CENTER
        }
    }
}


"Request climb to FL370":

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[2017-06-13 15:25:50 GMT] [136.775] [-27.9/-47.0 dBFS] [19.1 dB]
406F7B (Aircraft, Airborne) -> 216B45 (Ground station): Command
AVLC type: I sseq: 0 rseq: 3 poll: 0
X.25 Data: grp: 11 chan: 254 sseq: 5 rseq: 6 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a7 96 50 d1 0a ab 1e ce 40 09 4a a1 03 d9 9e 27 00
ATCDownlinkMessage ::= {
    header: ATCMessageHeader ::= {
        messageIdNumber: 4
        dateTime: DateTimeGroup ::= {
            date: Date ::= {
                year: 2017
                month: 6
                day: 13
            }
            timehhmmss: Timehhmmss ::= {
                hoursminutes: Time ::= {
                    hours: 15
                    minutes: 25
                }
                seconds: 50
            }
        }
        logicalAck: 0
    }
    messageData: ATCDownlinkMessageData ::= {
        elementIds: elementIds ::= {
            dM9Level: singleLevel: levelFlightLevel: 370
        }
    }
}


"Proceed direct to MIKOV":

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[2017-06-05 14:28:59 CEST] [136.975] [-12.9/-46.1 dBFS] [33.2 dB]
2B86F7 (Ground station, On ground) -> 42432C (Aircraft): Command
AVLC type: I sseq: 7 rseq: 3 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 2 rseq: 0 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 09 83 2c 28 85 54 8c 73 b0 12 82 4d 93 2e 7d 62 04 d0 36 68 e0
ATCUplinkMessage ::= {
    header: ATCMessageHeader ::= {
        messageIdNumber: 4
        dateTime: DateTimeGroup ::= {
            date: Date ::= {
                year: 2017
                month: 6
                day: 5
            }
            timehhmmss: Timehhmmss ::= {
                hoursminutes: Time ::= {
                    hours: 12
                    minutes: 28
                }
                seconds: 59
            }
        }
        logicalAck: 0
    }
    messageData: ATCUplinkMessageData ::= {
        elementIds: elementIds ::= {
            uM74Position: fixName: FixName ::= {
                name: MIKOV
            }
        }
    }
}


"Contact Rhein Radar ad 133.340":

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[2017-04-21 07:09:09 GMT] [136.775] [-10.4/-38.7 dBFS] [28.3 dB]
20B665 (Ground station, On ground) -> 3C6494 (Aircraft): Command
AVLC type: I sseq: 1 rseq: 6 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 7 rseq: 4 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 0f a3 30 17 68 45 4e 8a d2 10 1d 62 2c 4a b5 62 94 88 b2 67 20 a5 06 24 1a 40 6f f0 81 40 10 a0 e8
ATCUplinkMessage ::= {
    header: ATCMessageHeader ::= {
        messageIdNumber: 2
        dateTime: DateTimeGroup ::= {
            date: Date ::= {
                year: 2017
                month: 4
                day: 21
            }
            timehhmmss: Timehhmmss ::= {
                hoursminutes: Time ::= {
                    hours: 10
                    minutes: 52
                }
                seconds: 33
            }
        }
        logicalAck: 0
    }
    messageData: ATCUplinkMessageData ::= {
        elementIds: elementIds ::= {
            uM117UnitNameFrequency: UnitNameFrequency ::= {
                unitName: UnitName ::= {
                    facilityDesignation: EDUU
                    facilityName: RHEIN RADAR
                    facilityFunction: 0
                }
                frequency: frequencyvhf: 26668
            }
        }
    }
}


[szpajder]

There is a new release of dumpvdl2 (https://github.com/szpajder/dumpvdl2/releases/tag/v1.3.0) with new CPDLC-related features:

- CPDLC messages are now printed in a human-readable form (at last):

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[2018-04-11 08:30:33 CEST] [136.975] [-18.4/-48.9 dBFS] [30.5 dB]
2B86F7 (Ground station, On ground) -> 424336 (Aircraft): Command
AVLC type: I sseq: 3 rseq: 0 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 4 rseq: 5 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 09 83 2c 28 a5 8d 46 7a 10 12 82 54 ab 4e 4c e2 00 59 58 39 00
CPDLC Uplink Message:
Header:
  Msg ID: 5
  Timestamp: 2018-04-11 06:30:33
  Logical ACK: required
Message data:
  PROCEED DIRECT TO [position]
   Fix: TUSIN

[2018-04-11 09:51:34 CEST] [136.975] [-28.7/-49.1 dBFS] [20.3 dB]
10920A (Ground station, On ground) -> 4248EF (Aircraft): Command
AVLC type: I sseq: 0 rseq: 7 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 5 rseq: 4 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 0f a3 30 17 68 65 8d 47 ce 20 1d 62 2d 0a f5 e2 bc 1a 54 ed 41 af 06 0c 38 60 74 bc 82 6e f6 e7 20
CPDLC Uplink Message:
Header:
  Msg ID: 3
  Timestamp: 2018-04-11 07:51:34
  Logical ACK: required
Message data:
  CONTACT [unitname] [frequency]
   Unit name: EPWW, WARSZAWAACC, center
   VHF: 134.875 MHz

[2018-04-01 17:53:58 CEST] [136.975] [-26.2/-48.9 dBFS] [22.7 dB]
424368 (Aircraft, Airborne) -> 2A6198 (Ground station): Command
AVLC type: I sseq: 2 rseq: 4 poll: 0
X.25 Data: grp: 11 chan: 255 sseq: 6 rseq: 1 more: 0
CLNP PDU, compressed header:
COTP Data:
   00 a8 08 16 52 d0 cb 18 1f af 21 06 4a a2 11 02 c7 2c 5d 98
CPDLC Downlink Message:
Header:
  Msg ID: 3
  Timestamp: 2018-04-01 15:53:57
  Logical ACK: required
Message data:
  REQUEST [level]
   Flight level: 370
  DUE TO AIRCRAFT PERFORMANCE


- Supports decoding of FANS-1/A variant of CPDLC (ie. the one encapsulated in ACARS messages; it is also used on HFDL and Inmarsat):

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[2017-03-04 20:47:12] [136.975] [-18.8/-47.0 dBFS] [28.1 dB]
10A41A (Ground station, On ground) -> 78100B (Aircraft): Command
AVLC type: I sseq: 6 rseq: 6 poll: 0
ACARS:
Reg: .B-7898 Flight:
Mode: 2 Label: AA Blk id: G Ack: ! Msg no.:
Message:
/AKLCDYA.AT1.B-7898A11EF285326CC0E4DAA48E1D2AB269C5410E6499B0904E9F5104199327D78B110499C8275AB53D04693480958A
FANS-1/A CPDLC Message:
CPDLC Uplink Message:
Header:
  Msg ID: 2
  Timestamp: 07:47:10
Message data:
  CLIMB TO AND MAINTAIN [altitude]
   Flight level: 340
  REPORT LEVEL [altitude]
   Flight level: 340
  [freetext]
   CRUISE CLIMB NOT ALLOWED IN NZZO FIR


- Supports decoding of FANS-1/A ADS-C messages:

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[2018-04-03 04:45:11 CEST] [136.975] [-25.0/-48.8 dBFS] [23.9 dB]
4B191E (Aircraft, Airborne) -> 10920A (Ground station): Command
AVLC type: I sseq: 0 rseq: 1 poll: 0
ACARS:
Reg: .HB-JNI Flight: LX0139
Mode: 2 Label: B6 Blk id: 0 Ack: ! Msg no.: F94A
Message:
/CTUE1YA.ADS.HB-JNI0724BCD86D4448CA2A561F0D24B5106BC608CA0057249638661608CA000E5AD0D1C0001424BCD86D4448CA2A561F0D24B5106BC608CA0057249638661608CA009196
ADS-C message:
Basic report:
  Lat: 51.6623497
  Lon: 19.2070198
  Alt: 36000 ft
  Time: 2709.500 sec past hour (:45:09.500)
  Position accuracy: <0.05 nm
  NAV unit redundancy: OK
  TCAS: OK
Predicted route:
  Next waypoint:
   Lat: 51.6196060
   Lon: 18.9445496
   Alt: 36000 ft
   ETA: 87 sec
  Next+1 waypoint:
   Lat: 51.4501762
   Lon: 17.9447937
   Alt: 36000 ft
Earth reference data:
  True track: 255.4 deg
  Ground speed: 419.5 kt
  Vertical speed: 0 ft/min
Waypoint change event:
  Lat: 51.6623497
  Lon: 19.2070198
  Alt: 36000 ft
  Time: 2709.500 sec past hour (:45:09.500)
  Position accuracy: <0.05 nm
  NAV unit redundancy: OK
  TCAS: OK
Predicted route:
  Next waypoint:
   Lat: 51.6196060
   Lon: 18.9445496
   Alt: 36000 ft
   ETA: 87 sec
  Next+1 waypoint:
   Lat: 51.4501762
   Lon: 17.9447937
   Alt: 36000 ft