Telecommunications – Receiver or analog modulated signal frequency converter – With particular receiver circuit
Reexamination Certificate
1998-08-24
2001-03-06
Vo, Nguyen (Department: 2682)
Telecommunications
Receiver or analog modulated signal frequency converter
With particular receiver circuit
C340S010330
Reexamination Certificate
active
06198913
ABSTRACT:
CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing 35 U.S.C.§119 from an application entitled AUTOMATIC WAKE-UP DEVICE OF RADIO AUTOMATIC RECOGNITION TERMINAL AND COMMUNICATION METHOD USING THE TERMINAL earlier filed in the Korean Industrial Property Office on Aug. 31, 1997, and there duly assigned Ser. No.97-45398 by that Office.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an automatic wake-up device for a radio automatic recognition terminal and a communication method using the terminal. More particularly, the invention relates to an automatic wake-up device for a radio automatic recognition terminal and a communication method using the terminal, in which the radio automatic recognition terminal wakes up in response to various modes of waking up a terminal included in a vehicle in an electronic toll collection system.
2. Related Art
Recently, there has been proposed an electronic toll collection system (ETCS) which reduces the number of men and the time required for collecting tolls on a highway in order to smooth the flow of vehicle traffic.
Typically, an ETCS employs a communication beacon which transmits a radio signal to a communication zone through which a vehicle must pass. The vehicle includes a radio automatic recognition terminal which responds to a polling signal transmitted via the communication beacon as the vehicle passes through the communication zone so that a corresponding toll is automatically collected.
Most vehicle terminals include batteries which operate in a sleep mode at ordinary times, that is, when the vehicle is not near a toll station. The vehicle terminal is awakened when the vehicle approaches the communication beacon and then returns to the sleep mode after communicating with the communication beacon.
Two different wake-up arrangements are utilized in such systems. In a first arrangement, a wake-up beacon is disposed separate from the communication beacon, and the two beacons transmit on different frequencies. Such an arrangement has the disadvantage that, if the vehicle stops at the boundary between the wake-up zone and the communication zone for an extended period of time (such as due to a traffic jam), communication is disabled between the terminal and the beacon, and the vehicle terminal returns to the sleep mode.
A second arrangement does not employ separate beacons, but rather communication data and wake-up data are separately and distinctly encoded and transmitted from the same beacon. However, such an arrangement has the disadvantage that, when vehicles are traveling at high speed and the communication zone is too wide, a large number of vehicle terminals can be in the communication zone at the same time, and this disturbs normal communication.
Therefore, there is a need for the development of an automatic wake-up device for a radio automatic recognition terminal and related communication method that eliminate the problems stated above.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to an automatic wake-up device for a radio automatic recognition terminal and a communication method using the terminal that substantially obviate one or more of the problems, limitations and disadvantages set forth above.
An object of the present invention is to provide an automatic wake-up device for a radio automatic recognition terminal and a communication method using the terminal, in which a vehicle terminal in the normal mode can wake up in response to either of the two waking-up methods described herein, and in which a vehicle terminal in the sleep mode can wake up again after passing a wake-up zone.
To accomplish the object of the present invention, there is provided an automatic wake-up device for a radio automatic recognition terminal, comprising: an antenna for picking up a radio signal; a band pass filter for filtering the radio signal picked up by the antenna to obtain a signal having a frequency corresponding to the frequency band of a wake-up signal; a first low pass filter for smoothing the signal which passed the band pass filter so as to generate an average DC level; a first comparator for comparing the signal level obtained by the first low pass filter with a predetermined reference level to determine if it is the wake-up signal, and for generating a corresponding result; a second low pass filter for detecting the DC level of data for waking-up, as amplified by the antenna; a second comparator for comparing the DC level of data for waking-up detected by the second low pass filter with a predetermined reference level to determine if it is the wake-up signal; a CPU for controlling the overall operation of a vehicle terminal, the CPU being normally in a sleep mode; a wake-up controller for waking up the CPU when the first comparator or the second comparator detects the normal wake-up signal; and a power switch which is turned on under the control of the CPU after waking-up of the CPU to provide power to other portions of the vehicle terminal.
To accomplish the objects of the invention, there is also provided a communication method using a radio automatic recognition terminal. In accordance therewith, a communication zone is located in a predetermined area of a lane, and a polling signal is transmitted to the communication zone to process a radio signal related to toll collection when a radio automatic recognition terminal included in a vehicle passing through the communication zone responds to the polling signal. Toll collection is then performed. The method comprises the steps of waiting for a predetermined period of time after the transmission of the polling signal, and then transmitting a radio signal to wake up the terminal for a predetermined period of time when the radio automatic recognition terminal does not respond to the polling signal within the waiting time.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
REFERENCES:
patent: 5310999 (1994-05-01), Claus et al.
patent: 5581249 (1996-12-01), Yoshida
patent: 5613213 (1997-03-01), Naddell et al.
patent: 5640156 (1997-06-01), Okuda et al.
patent: 5758278 (1998-05-01), Lansdowne
patent: 5790946 (1998-08-01), Rotzoll
patent: 5806007 (1998-09-01), Raith et al.
Lim Sung-Bin
Sung Tae-Kyung
Bushnell , Esq. Robert E.
Samsung Electronics Co,. Ltd.
Vo Nguyen
LandOfFree
Automatic wake-up device for radio automatic recognition... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic wake-up device for radio automatic recognition..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic wake-up device for radio automatic recognition... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2442945