On receipt of a request related to picture display from {HEAD ~ a user terminal}, a central device transmits an instruction to the plurality of distribution devices and to the plurality of receiving devices, according to a usage condition of the transmission line and the number of {TAIL ~ simultaneously distributed pictures} 
On receipt of a request related to picture display from { HEAD ~ a user terminal } , a central device transmits an instruction to the plurality of distribution devices and to the plurality of receiving devices , according to a usage condition of the transmission line and the number of { TAIL ~ simultaneously distributed pictures }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL