Jamming Detection

The Antares 4G can detect GPS and cellular jamming through the modem's built-in jamming detection capability.

How It Works

The modem continuously monitors the radio frequency environment. When jamming is detected:

1. Signal F23 (SIGNAL_MDM_JAMMING_DETECTED) activates.
2. If jamming persists, signal G04 (SIGNAL_MDM_JAMMING_PERSISTED) activates.

Signals

Signal	Name	Description
F23	SIGNAL_MDM_JAMMING_DETECTED	Momentary jamming detection event
G04	SIGNAL_MDM_JAMMING_PERSISTED	Jamming condition continues to persist

Configuring an Event for Jamming

Use the ED command to create an event that triggers when jamming is detected:

Objective: Send a report when jamming is detected.

Command:

>SED00NA0;F23+<

Field	Value	Description
ED	Event Definition	Command
00	Index	Event number (E00)
N	Handler	N = Normal Report (send position report)
A	Event ID	A type event
0	Destination	Destination address 0
F23	Signal	Jamming detected signal
+	Sense	Positive edge (signal goes HIGH)

Query the event:

>QED00<

Response:

>RED0NA0;F23+<

Recommended Response to Jamming

When jamming is detected:

1. Log the event with a position report.
2. If jamming persists (G04), escalate the alert.

JO Extended Tag

When jamming persists long enough to activate signal G04, every outbound TAIP report automatically includes the ;JO tag.

• The tag is appended after any user-configured extended tags.
• It is a system-forced indicator and cannot be added or removed via tag-list configuration.
• It disappears from reports as soon as G04 deactivates.

Example TAIP string with JO tag:

>REV0048131240586+2578391-0802945201228512;SV=8;JO;ID=869487069338209<

Limitations

• Detection accuracy depends on the modem firmware and signal environment.
• False positives may occur in areas with dense cellular activity.