CircularRange is available as:
This model shows a transmitter (at the left) and a receiver (at the right), where the receiver moves in and out of range as the model executes. The channel is a LimitedRangeChannel, which is a simple wireless channel model where the transmitter specifies via a parameter in its output port the distance over which it can transmit. In this model, that distance is shown graphically as the radius of the circular icon for the transmitter. As the model executes, at random times, the range of the transmitter decreases.