Patent ID: 8222992

Claim:
A control system comprising: a control device provided in a vehicle that performs a control of a predetermined process, and a plurality of portable communication devices for communicating with the control device; wherein the control device includes: a first transmission unit for transmitting a request signal requesting for transmission of a response signal to at least one of the plurality of portable communication devices, a first reception unit for receiving the response signal transmitted through a predetermined procedure from at least one of the plurality of portable communication devices in response to the request signal transmitted by the first transmission unit, an authentication unit for performing authentication of at least one of the plurality of portable communication devices using identification information of at least one of the plurality of portable communication devices contained in the response signal received by the first reception unit and identification information of at least one of the plurality of portable communication devices registered in advance, and a process executing unit for executing the predetermined process when the authentication of at least one of the plurality of portable communication devices by the authentication unit is successful; and wherein at least one of the plurality of portable communication devices includes: a first storage unit for storing transmission scheduled time information indicating a time scheduled to transmit the response signal assigned to at least one of the plurality of portable communication devices, a second reception unit for receiving the request signal transmitted from the first transmission unit, and a second transmission unit for performing a first transmission operation of transmitting the response signal corresponding to the request signal received by the second reception unit to the control device at a time common with the other portable communication devices after receipt of the request signal, and a second transmission operation of transmitting the response signal to the control device at a time different from times assigned to other portable communication devices after completion of the first transmission operation based on the transmission scheduled time information stored in the first storage unit.