netsim_manager

The netsim_manager process is responsible for:

• Interfacing with the vehicle simulators
  • Maintaining a record of the current position of the simulated vehicles
  • Writing simulated vehicle position data as a fake GPS serial stream
• Forwarding various messages to the correct environment in the Virtual Ocean simulator
  • Channel impulse responses (netsim::groups::impulse_request / netsim::groups::impulse_response)
  • Predicted performance metric data (netsim::groups::performance_request / netsim::groups::performance_response)
  • BELLHOP model requests (netsim::groups::bellhop_request / netsim::groups::bellhop_response): used by Liaison tab for visualizing predicted transmission loss.

For detail on the specific publish/subscribe interfaces, see the Architecture page.

Configuration

Configuration is given as a Protobuf TextFormat file for the netsim::protobuf::NetSimManagerConfig message.

All available configuration values can be obtained by the -e flag to netsim_manager.

For example,

netsim_manager -e

yields

app { ... } # standard Goby3 app configuration
interprocess { ... } # standard Goby3 interprocess configuration (for connecting to gobyd)
sim_env_pair {  # repeated for each expected simulated vehicle 
                # (repeated)
  modem_tcp_port:   # TCP port used for connecting to the modem 
                    # data interface (62000, 62001, etc. on 
                    # audioserver). This is used as a unique 
                    # identifier for a given vehicle simulator 
                    # (required)
  endpoint_ip_address: ""  # IP address for connecting remote 
                           # endpoint (required)
  environment_id:   # unique id used to map to env_bounds{} 
                    # (required)
}
env_bounds {  # validity bounding region of the ocean for each 
              # Virtual Ocean environment (repeated)
  environment_id:   # unique id for this environment (required)
  lat_min:   # minimum latitude in decimal degrees (required)
  lon_min:   # minimum longitude in decimal degrees (required)
  lat_max:   # maximum latitude in decimal degrees (required)
  lon_max:   # maximum longitude in decimal degrees (required)
  depth_min: 0  # minimum depth in meters (optional) (default=0)
  depth_max:   # maximum depth in meters (required)
}
gps_out {  # Set if a synthesized $GPRMC GPS message is desired 
           # for a given simulated vehicle (repeated)
  modem_tcp_port:   # Which vehicle to output, as referenced by 
                    # its modem TCP port set in sim_env_pair{} 
                    # (required)
  serial {  # Output serial settings (required)
    port: "/dev/ttyUSB0"  # Serial port path (required)
    baud: 57600  # Serial baud (required)
    end_of_line: "\n"  # End of line string. Can also be a 
                       # std::regex (optional) (default="\n")
    flow_control: NONE  # Flow control: NONE, SOFTWARE (aka 
                        # XON/XOFF), HARDWARE (aka RTS/CTS) (NONE, 
                        # SOFTWARE, HARDWARE) (optional) 
                        # (default=NONE)
  }
}

Each vehicle simulator is indexed using the TCP server port that it uses to connect to socat (which forwards the TCP data to the actual modem interface over serial, TCP, UDP, etc.). On the audioserver these values are 62000-62007. netsim_manager itself uses TCP port 61999 by default for the interface with the vehicle simulators (see Vehicle Simulator Connections page).

Use the sim_env_pair field, each vehicle simulator must be mapped to a desired environment (region of the ocean) that is operating in. These environments are defined by the bounds set in the corresponding env_bounds field. These bounds should be set to ensure that the underlying models used to produce the impulse responses, etc. are valid within them.