Dynamic bandwidth sharing

The dynamic threshold rule which shares the bandwidth of the sharing medium between two or more equipment is established. Equipment determines the size of the bandwidth which can use a first half medium, and reserves the bandwidth to the bandwidth which can be used, The demand from the equipment of a specific quantity of bandwidth is received, and when the bandwidth which can be used is insufficient for satisfying a demand, the bandwidth exceeding the rate of the bandwidth which can be used when bandwidth is reserved is abandoned. It is exempted from the demand whose equipment of at least one kind can distinguish the equipment of a different kind, and increase more than the rate of equipment that the rate of the specific equipment of a kind is not a specific kind, or abandons bandwidth.