Patent ID: 8675676
Filing Date: 2014-03-18
Classification: H04L,H04W,Y02D

Abstract:
1. A network system comprising: a controller; and a plurality of terminals connected to said controller via a network, wherein said controller comprises a first communication unit configured to communicate with said terminals via the network, a first request unit, a counting unit, a terminal number determination unit, a limited time determination unit, and a second request unit, each of said terminals comprising a second communication unit configured to communicate with said controller via the network, a first response unit, and a second response unit, said first request unit being configured to send a first request signal to the plurality of said terminals via said first communication unit, the first request signal including first limited time information indicative of a first limited time period, the first limited time period being defined to be a predetermined range within which said first communication unit receives signals respectively from all of a maximum number of said terminals allowed to be connected to the network, said first response unit being configured to, in response to receiving the first request signal via said second communication unit, send a first response signal to said controller via said second communication unit before a lapse of the first limited time period indicated by the first limited information included in the first request signal, said counting unit being configured to count the first response signals which have been received by said first communication unit within the first limited time period, and output the number of the first response signals, said terminal number determination unit being configured to determine a total number of said terminals on the basis of the number of the first response signals obtained from said counting unit, said limited time determination unit being configured to determine a second limited time period being defined to be a range within which said first communication unit receives signals from all of the total number of said terminals determined by said terminal number determination unit, said second request unit being configured to send a second request signal to the plurality of said terminals via said first communication unit, the second request signal including second limited time information indicative of the second limited time period determined by said limited time determination unit, and said second response unit being configured to, in response to receiving the second request signal via said second communication unit, send a second response signal to said controller via said second communication unit before a lapse of the second limited time period indicated by the second limited information included in the second request signal.