MAVLink High Latency Mode
ArduPilot supports the MAVLink High Latency protocol. This designed for very low bandwidth or high cost links, such as satellite or LoRA.
Within this protocol, only the HIGH_LATENCY2 MAVLink message is sent once per 5 seconds. Any responses to MAVLink commands or requests (such as command acknowledgements or parameter requests) will be sent too.
MAVLink High Latency is available as an option on any telemetry port. A typical use case is to have a standard MAVLink telemetry port for initial configuration and system checkout - usually a radio modem or 4G link. A low-bandwidth modem will be connected on a 2nd telemetry port, which the user can activate
Make sure the desired telemetry port protocol is set to option MAVLink High Latency (
SERIALn_PROTOCOL = 43)
In MAVProxy use the
link hl on|off to enable or disable sending telemetry on the High Latency port
In QGroundControl connect using the
High Latency option to enable sending telemetry on the High Latency port
In Mission Planner, use
Actions -> Do Action to enable or disable sending telemetry on the High Latency port
MAVLink High Latency will only send very basic, high level information of the vehicle’s position and status.
The bandwidth requirements of MAVLink High Latency are very minimal - less than 100 bytes/sec in most cases.
The enable/disable of a High Latency link can be sent over any telemetry link and will enable/disable all High Latency links on the vehicle.