---
# System prepended metadata

title: RTTMAS - MQTT Payloads
tags: [rttmas]

---

# RTTMAS - MQTT Payloads

`QoS = 0`

### User 端定期上報（Case 1: 辨識結果上傳）

> Note: The `UID` field in the topics is the reporter's UID generated by Firebase for the client's device.

Topic: `/uplink/report/<UID>`
```json
{
  // (int)
  "report_type": 10,
    
  // Timestamp in UNIX seconds (int/long)
  "report_time": 18203287771,

  // GPS latitude (float/double) and longitude (float)
  "lat": 24.3551,
  "lon": 121.2551,
    
  // Speed obtained by device GPS (float, in km/h)
  "gps_speed_kmh": 29.6,
    
  // The heading (bearing) obtained by device GPS (float, in degrees)
  "gps_heading": 153.6,
    
  // The recognized plate numbers (Array<string>)
  // Skip this field, if no plates have been detected
  "reported_plates": ["ABC-1234", "BCD-3456", "4321-XY"]
}
```


### User 端定期上報（Case 2: 原圖上傳）
Topic: `/uplink/report/<UID>`
```json
{
  // (int)
  "report_type": 20,
    
  // Timestamp in UNIX seconds (int/long)
  "report_time": 18203287771,

  // GPS latitude (float/double) and longitude (float)
  "lat": 24.3551,
  "lon": 121.2551,
    
  // Speed obtained by device GPS (float, in km/h)
  "gps_speed_kmh": 29.6,
    
  // The heading (bearing) obtained by device GPS (float, in degrees)
  "gps_heading": 153.6,
    
  // The original image capture. Encode this using base64
  "raw_image": <base64_encoded_image_data>
}
```