Automatic wake-up device for radio automatic recognition terminal and communication method using the terminal

An automatic wake-up device for a radio automatic recognition terminal, comprising:

• antenna means for picking up a radio signal;
• first circuit means for receiving and processing said radio signal picked up by said antenna means, and for differentiating between a wake-up signal having a first frequency and a communication signal having a second frequency so as to generate a first output signal indicating receipt of the wake-up signal;
• second circuit means for receiving and processing said radio signal picked up by said antenna means so as to differentiate between data for waking up the terminal and data for communication alternately transmitted, and generating a second output signal indicating receipt of said data for waking up the terminal;
• and
• wake-up means for converting the terminal from a sleep mode to an awake mode in response to reception of one of said first output signal and said second output signal from said first circuit means and said second circuit means, respectively.

A communication method using a radio automatic recognition terminal mounted in a vehicle, wherein a communication zone is located in a predetermined area of a lane through which the vehicle passes, said method comprising the steps of:

• transmitting a polling signal to the communication zone;
• waiting for a predetermined period of time after the transmission of the polling signal;
• determining whether there is a response to the polling signal by the terminal mounted in the vehicle;
• and
• when there is no response to the polling signal from the terminal mounted in the vehicle, transmitting a radio signal to wake up the terminal mounted in the vehicle for a predetermined period of time;
• said method further comprising the steps of operating said radio automatic recognition terminal in a first mode of operation wherein the radio automatic recognition terminal distinguishes between a first frequency of a wake-up signal and a second frequency of a communication data signal, and operating said radio automatic recognition terminal in a second mode of operation wherein the radio automatic recognition terminal does not distinguish between frequencies of the wake-up signal and the communication data signal.

A communication method for use with a toll collection system, comprising the step of:

• providing a radio automatic recognition terminal in a vehicle passing through the toll collection system;
• providing the radio automatic recognition terminal with a capability of operating in first and second modes of operation;
• in the first mode of operation, transmitting a wake-up signal having a first frequency different from a second frequency of a communication signal to a wake-up zone of the toll collection system when the wake-up zone and a communication zone of the toll collection system are separately located;
• in the second mode of operation, transmitting the wake-up signal and the communication signal alternately without distinguishing the wake-up zone and the communication zone from each other;
• operating said radio automatic recognition terminal in said first mode of operation so as to respond to the wake-up signal and the communication signal when the wake-up signal is transmitted in said first mode of operation;
• operating said radio automatic recognition terminal in said second mode of operation when the wake-up signal and the communication signal are transmitted in said second mode of operation.