| Downlink Format | Description | UT |
|---|---|---|
| DF-0 | Short air-air surveillance (ACAS) | ✓ |
| DF-4 | Surveillance, altitude reply | ✓ |
| DF-5 | Surveillance, identify reply | ✓ |
| DF-11 | All-call reply | ✓ |
| DF-16 | Long air-air surveillance (ACAS) | ✓ |
| DF-17 | Extended squitter (ADSB) | ✓ |
| DF-18 | Extended squitter/non transponder (ADSB) | ✓ |
| DF-19 | Military extended squitter | ✓ |
| DF-20 | Comm-B altitude reply | ✓ |
| DF-21 | Comm-B identify reply | ✓ |
| DF-24 | Comm-D (ELM) | ✓ |
| BDS | Description | UT |
|---|---|---|
| 0,0 | No message available | ✓ |
| 0,5 | (ADSB) Airborne position | |
| 0,6 | (ADSB) Surface position | ✓ |
| 0,7 | Status | |
| 0,8 | (ADSB) Aircraft identification | ✓ |
| 0,9 | (ADSB) Airborne velocity | ✓ |
| 1,0 | Data link capability report | |
| 1,7 | Common usage GICB capability report | |
| 2,0 | Aircraft identification | ✓ |
| 3,0 | ACAS resolution advisory | |
| 4,0 | Selected vertical intention | ✓ |
| 4,4 | Meteorological routine air report | ✓ |
| 4,5 | Meteorological hazard report | ✓ |
| 5,0 | Track and turn report | ✓ |
| 6,0 | Heading and speed report | ✓ |
| 6,1 | (ADSB) Emergency report | ✓ |
| 6,2 | (ADSB) Target and status | ✓ |
| 6,5 | (ADSB) Operational status | ✓ |
| BDS | Description | Formats | UT |
|---|---|---|---|
| No position information | 0 | ✓ | |
| 0,5 | Airborne position | 9-18 and 20-22 | |
| 0,6 | Surface position | 5-8 | |
| 0,8 | Aircraft identification | 1-4 | |
| 0,9 | Airborne velocity | 19 | |
| 6,1 | Emergency report | 28 | |
| 6,2 | Target and status | 29 | |
| 6,5 | Operational status | 31 |
TBD
| Code | Description | UT |
|---|---|---|
| 3,0 | Resolution Advisory | ✓ |