An information processing system includes a GW and a portable communication device. The GW includes a transmitter that transmits, to the portable communication device that is located within a given area, a request to transmit information; a receiver that receives a response to the request to transmit information from the portable communication device; and a data acquisition controller that, when the number of responses received is larger than a maximum allowable number to the GW, adjusts the area to which the request to transmit information is transmitted such that the number of responses is equal to or smaller than the maximum allowable number and that, when the number of responses is equal to or smaller than the maximum allowable number to the GW, adjusts an area to which the request to transmit information is transmitted, which is an area different from the area to which the request has been transmitted.