Automatic Packet Reporting System

| September 11, 2026 | Amateur Radio (Ham Radio) | No Comments

Occasionally Indian Hams also post their trips being tracked by APRS (Automatic Packet Reporting System). On Indian highways, APRS tracking works through a hybrid system, but it depends entirely on how your tracker is configured. There are two distinct ways your location updates reach aprs.fi:

1. The Traditional Way: Physical Receivers (RF to Internet)

If you are using a traditional Amateur Radio (Ham) hardware tracker:

  • No Direct Internet: Your device does not send data directly to the cellular internet. Instead, it blasts out a VHF radio packet (typically using AX.25 packet radio protocol) over the airwaves.
  • Highways Receivers: These packets are picked up by volunteer-run physical receivers located near major cities, towns, or elevated terrain along the highway.
  • Digipeaters & IGates:
    • If your signal hits a Digipeater (Digital Repeater), it simply copies and retransmits your packet with higher power to extend its range.
    • When your signal hits an IGate (Internet Gateway), that receiver captures the radio packet, converts it to data, and forwards it directly to the global APRS-IS internet network, which is what feeds aprs.fi .
  • The Reality in India: Traditional VHF APRS coverage on Indian highways can be spotty. While major metros (like Bengaluru, Mumbai, Chennai, and Delhi) have excellent coverage maintained by local ham radio clubs and individuals, vast stretches of rural national highways may lack a nearby physical IGate receiver.

2. The Modern Way: Cellular/App-Based (Direct to Internet)

Because physical radio receivers are not uniformly present across all thousands of kilometers of Indian highways, many Indian hams use APRS-IS over cellular data (often called “Data APRS” or “Cellular APRS”):

  • Direct to Internet: If you use a smartphone app (like APRSdroid on Android or APRS.fi app on iOS) or a specialized cellular-linked tracker, the device bypasses the radio waves entirely.
  • How it routes: The app uses your phone’s built-in GPS for coordinates and transmits them over the local 4G/5G cellular network. It connects directly to the internet via the APRS-IS servers, instantly plotting your icon onto aprs.fi .

How to check which method you are using on a route:

If you look at your own or someone else’s callsign on the aprs.fi map :

  1. Click on the station’s icon.
  2. Look at the “Path” or info section.
  3. If it says TCPIP or qAC, the packet went directly from a phone/internet device to the web.
  4. If you see radio terms followed by a specific callsign, it means a physical gateway receiver on the ground intercepted the radio signal and uploaded it for them.