To measure the latency of the different robot commands, a small Java applet was developed that sends a command to the robot, waits for a reply, and measures the time delay.

Two test series were performed:

    *local measurement executed using as client a computer located in the same building as robot

    *remote measurement series executed from a different country

Four commands measured:

    BO       request for robot position
    BU       request for robot ultrasound sensor values
    ASF     stop the robot
    M0p0   reset the position of the pan & tilt unit

The first two commands are executed directly from the host server and relative delay time is an indication for the latency due exclusively to the Internet.

The other two commands are sent to the robot providing a measurement of the combined latency due to the Internet and the time for the robot to execute an operation.