The present invention can code an I-picture that satisfies a predetermined condition using parameter information. By first using the capacity of all links leading to the final destination of traffic, the remaining capacity is freed up for best effort traffic. This device has a data transmitter that broadcasts a group profile repetitively in the prescribed area. The radially inner portion and the radially outer portion are detachably attached to each other so that the radially outer portion is replaceable with another radially outer portion having a dimension suitable for covering a cutting blade of a different dimension.