Apparatus and method for detecting a mobile phone in idle state

• US 6,490,455 B1
• Filed: 01/29/1999
• Issued: 12/03/2002
• Est. Priority Date: 10/20/1998
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Young-Soo, Lee, Yun-Hee, Park, Sang-Hwan
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Nguyen, Simon
• Application Number:
  US09/240,030
• Time in Patent Office: 1,404 Days
• Field of Search: 370/342, 455/411, 455/414, 455/432, 455/456, 455/461, 455/88, 455/421, 455/229, 455/67.1, 455/67.7, 455/1, 455/63, 455/517, 455/561, 455/565, 455/437, 340/539
• US Class Current: 455/456.4
• CPC Class Codes: H04K 2203/16 for telephony
• CPC Class Codes: H04K 3/45 characterized by including monitoring of the target or target signal, e.g. in reactive jammers or follower jammers for example by means of an alternation of jamming phases and monitoring phases, called "look-through mode"
• CPC Class Codes: H04K 3/65 using deceptive jamming or spoofing, e.g. transmission of false signals for premature triggering of RCIED, for forced connection or disconnection to/from a network or for generation of dummy target signal
• CPC Class Codes: H04K 3/84 related to preventing electromagnetic interference in petrol station, hospital, plane or cinema
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration

Abstract

A method and apparatus for detecting mobile phone in an Idle State are disclosed. A signal-generating unit generates a pseudo base station signal for transmission to a mobile phone in a detection area. A detecting unit detects a response signal that the mobile phone transmits in response to the pseudo base station signal. An alarm-generating unit generates an alarm when the detecting unit detects the response signal. Preferably, the pseudo base station signal includes new zone information, such that the mobile phone responds by transmitting a location registration signal which is detected by the detecting unit. The method and apparatus are advantageous in that they can apprise a mobile phone user within a specific area that the user'"'"'s mobile phone is turned on, by detecting the mobile phone in Idle State passing a detection area. The method and apparatus may prevent public injury or interference with electronic equipment by restricting mobile phone use in a building or airplane.

Claims

1. An apparatus for detecting a mobile phone in an idle state comprising:

a signal-generating unit for generating a pseudo base station signal based on zone information of neighboring base stations for transmission to a mobile phone in a detection area;

a detecting unit adapted to detect a response signal that a mobile phone transmits in response to the pseudo base station signal; and

an alarm-generating unit for generating an alarm when said detecting unit detects said response signal.

2. The apparatus as set forth in claim 1, wherein said zone information includes Pseudorandom Noise (PN) code offset, zone number, a system identifier (SID) and a network identifier (NID).

3. The apparatus as set forth in claim 1, wherein said signal-generating unit generates said pseudo base station signal using a system reference clock derived from a Global Positioning System (GPS) receiver, said GPS receiver receiving time-information from GPS satellites to generate the system reference clock.

4. The apparatus as set forth in claim 1, further including circuitry for analyzing neighboring base stations, said circuitry being adapted to receive signals transmitted by neighboring base stations in an overhead channel and extract neighboring base station information therefrom, wherein said signal-generating unit generates said pseudo base station signal based on said neighboring base station information.

5. The apparatus as set forth in claim 4, wherein said circuitry for analyzing neighboring base stations comprises:

(a) a first receiving antenna for receiving radio frequency (RF) signals through the overhead channel from neighboring base stations;

(b) a first receiving filter to filter said received RF signals;

(c) a first frequency down-converter to convert the filtered signal to a baseband signal;

(d) a forward demodulator to demodulate the baseband signal by despreading; and

(e) an overhead channel analyzer to analyze the demodulated signal and generate said neighboring base station information.

6. The apparatus as set forth in claim 4, wherein said extracted neighboring base station information includes transmit frequency status, pilot signal strength and PN code offset.

7. The apparatus as set forth in claim 1, wherein said signal-generating unit comprises:

(a) a forward modulator for generating an overhead channel signal using the reference clock received by said GPS receiver;

(b) an up-converter for converting the overhead channel signal to an RF signal in a frequency band of a code division multiple access (CDMA) system;

(c) a transmit power amplifier for amplifying the RF signal;

(d) a transmitting filter for filtering the amplified signal; and

(e) a transmitting antenna for transmitting the filtered signal as said pseudo base station signal.

8. The apparatus as set forth in claim 7, wherein said transmit power amplifier amplifies the RF signal to a power level of only several milliwatts, so as to prevent interference with electronic equipment outside a specific detection area.

9. The apparatus as set forth in claim 7, wherein said transmitting antenna transmits an overall forward frequency band of said CDMA system, and forms a narrow beamwidth directed towards a specific detection area.

10. The apparatus as set forth in claim 1, wherein said apparatus transmits said pseudo base station signal in response to a signal from an object detector indicating that an object is within a specific detection area.

11. The apparatus as set forth in claim 1, wherein said detecting unit comprises:

(a) a second receiving antenna for receiving radio frequency (RF) signals through an access channel from a mobile phone in Idle State;

(b) a receiving filter for filtering said received RF signals;

(c) a down-converter for converting the filtered signal to a baseband signal; and

(d) a reverse demodulator for despreading and demodulating the baseband signal and forwarding an alarm signal to an alarm-generating unit when said response signal of the mobile phone is detected within said demodulated signal.

12. The apparatus as set forth in claim 11, wherein the frequency separation, at a given time, between a passband of said receiving filter and a transmitting filter of said signal generating unit that filters said pseudo base station signal, is selected from the group consisting of 45 MHz and 90 MHz.

13. The apparatus as set forth in claim 11, wherein said receiving filter and a transmitting filter of said signal generating unit that filters said pseudo base station signal each have a passband of 1.25 MHz.

14. The apparatus as set forth in claim 1, wherein said signal-generating unit comprises:

(a) circuitry for generating said pseudo base station signal at frequencies and a protocol of a code division multiple access (CDMA) cellular system; and

(b) circuitry for generating said pseudo base station signal at frequencies and a protocol of a CDMA personal communication service (PCS) system,

and wherein said detecting unit comprises;

(a) circuitry for detecting a signal that said mobile phone transmits at frequencies and a protocol of a CDMA cellular system; and

(b) circuitry for detecting a signal that said mobile phone transmits at frequencies and a protocol of a CDMA personal communication service (PCS) system.

15. The apparatus as set forth in claim 1, wherein said detection area is an entranceway.

16. An apparatus for detecting a mobile phone in an idle state comprising:

(a) a GPS receiver for receiving time information from a satellite and generating therefrom a system reference clock;

(b) a signal-generating unit for generating a pseudo base station signal based on zone information of neighboring base stations for transmission to said mobile phone in said idle state in a specific detection area, said pseudo base station signal causing said mobile phone in said idle state to transmit location registration signals;

(c) a detecting unit for detecting said location registration signals; and

(d) an alarm-generating unit for generating an alarm when said detecting unit detects said location registration signals.

17. The apparatus as set forth in claim 16, wherein said signal-generating unit generates said pseudo base station signal based on neighboring base station information received through overhead channels transmitted by said neighboring base stations.

18. The method of claim 17, wherein said pseudo base station signal is transmitted in a standard overhead channel of a wireless communications system.

19. A method for detecting a mobile phone in an idle state, said method comprising the steps of:

(a) transmitting a pseudo base station signal within a detection area, using zone information of neighboring base stations to generate said pseudo base station signal, and said pseudo base station signal causing said mobile phone in said idle state in said detection area to transmit a response signal; and

(b) receiving said response signal from said mobile phone and generating an alarm.

20. The method of claim 19, wherein said pseudo base station signal includes a pilot channel signal which is transmitted at a power level sufficient for a mobile phone in said detection area to receive said pilot channel signal with more power than pilot channel signals of all neighboring base stations in the vicinity of said detection area.

21. A method for detecting a mobile phone in an idle state, said method comprising the steps of:

(a) generating a pseudo base station signal by a signal-generating unit using zone information of neighboring base stations, said pseudo base station signal having new zone information;

(b) transmitting said pseudo base station signal to a mobile phone within a detection area;

(c) receiving said pseudo base station signal and transmitting a location registration signal to a detecting unit by a mobile phone in said idle state;

(d) receiving the location registration signal from the mobile phone by said detecting unit; and

(e) generating an alarm when said detecting unit receives the location registration signal from said mobile phone.

22. The method as set forth in claim 21, wherein said step of generating a pseudo base station signal comprises the steps of:

(a) receiving an overhead channel signal from a base station located near the detection area; and

(b) obtaining information of neighboring base stations by analyzing the received overhead channel signals.

23. The method as set forth in claim 22, wherein the step of receiving an overhead channel signal includes tuning to all possible overhead channels used by base stations of a code division multiple access (CDMA) system.

24. The method as set forth in claim 21, wherein the step of generating a pseudo base station signal is performed when an object detection signal is received from an object detector indicating that an object has entered the detection area.

25. The method as set forth in claim 21, wherein said pseudo base station signal is generated having time-related access parameters of an access channel in which said mobile phone transmits said location registration signal, said time-related access parameters being sufficient to reduce transmission-time for the location registration signal of said mobile phone.

26. The method as set forth in claim 21, wherein said pseudo base station signal is generated sequentially in a plurality of overhead frequency channels of a code division multiple access (CDMA) system.

27. The method as set forth in claim 21, wherein the step of receiving the location registration signal is performed by sequentially tuning to different frequency channels to enable reception of said location registration signal in any one of said different frequency channels.

28. The method as set forth in claim 21, wherein the step of receiving the location registration is performed by sequentially tuning only to access frequency channels being used in base stations located near the detection area, to enable reception of said location registration