System and method for determining the location of a mobile device within a wireless network

• US 6,776,334 B1
• Filed: 02/22/2001
• Issued: 08/17/2004
• Est. Priority Date: 02/22/2001
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Garg, Atul
• Primary Examiner(s): Le, Thien M.
• Application Number:
  US09/792,140
• Time in Patent Office: 1,272 Days
• Field of Search: 235/384, 235/382, 235/380, 235/492, 235/441, 235/382.5, 235/375, 235/383, 235/486, 235/487, 455/456.2, 455/412.1, 455/456.1, 455/456.5, 455/457, 455/466
• US Class Current: 235/384
• CPC Class Codes: G01S 1/7036 Collocated with electrical equipment other than beacons
• CPC Class Codes: G01S 1/7038 Signal details
• CPC Class Codes: G01S 2201/01 adapted for specific applications or environments
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

A system for locating a mobile device within a wireless network includes detecting one of a plurality of infra red beacon signals, each from a location beacon. A memory stores a plurality of predetermined transmission frames, each corresponding to one of the plurality of beacon signals. A transmitter selects one of a plurality of predetermined transmission frames in accordance with the detected beacon signal and transmits the predetermined frame to a remote monitoring device across a network.

Claims

1. A system for locating a mobile device within a wireless network environment, the system comprising:

a) an access point for wirelessly receiving a data frame from the mobile device and forwarding the data frame to a location monitoring appliance on a wired network backbone;

b) a plurality of location beacons, each transmitting a unique beacon signal representing the location of the beacon; and

c) wherein the mobile device includes a beacon detection circuit for receipt of the beacon signal, a frame selection circuit for selecting one of a plurality of predetermined data frames as representative of the location of the mobile device for transmission in response to the beacon signal, and a transmission circuit for transmitting the selected data frame and wherein the location monitoring appliance provides data representative of the mobile device and the beacon signal received by the mobile device.

2. The system for locating a mobile device within a wireless network environment of claim 1, wherein the each of the plurality of location beacons transmits the beacon signal utilizing modulated illumination and the beacon detection circuit detects the modulated illumination and provides a signal representative thereof.

3. The system for locating a mobile device within a wireless network environment of claim 2, wherein the mobile device includes a memory storing, for each of the predetermined data frames, a set of signal values representing transmission of the predetermined message compliant with the network protocol and wherein the frame selection circuit receives the signal from the beacon detection circuit and selects the predetermined message associated therewith.

4. The system for locating a mobile device within a wireless network environment of claim 3, wherein the transmission signal values represent a network address of the location monitoring appliance, a network address of the mobile device, a network protocol compliant preamble and the predetermined message.

5. The system for locating a mobile device within a wireless network environment of claim 4, wherein the transmission signal values represent a baseband transmission and the transmitter includes a D/A converter generating an analog baseband signal and an analog mixer for generating the modulated carrier.

6. The system for locating a mobile device within a wireless network environment of claim 5, wherein the location monitoring appliance activates at least one of an audio and visual alarm based on the network address of the mobile device and the predetermined message matching an alarm condition.

7. The system for locating a mobile device within a wireless network environment of claim 5, wherein the at least one of an audio and visual alarm is activated on a mobile computing device and the location monitoring appliance activates the alarm by sending a signal to the mobile computing device via the wireless network.

8. A network device for reporting its location within a wireless network to a remote computing device, the network device comprising:

a) a location detection circuit for receiving a beacon signal from one of a plurality of location beacons;

b) a memory storing a plurality of sets of transmission signal values representing a transmission frame of a predetermined message complying with a predetermined network protocol, each set of transmission signal values associated with one of the plurality of beacon signals;

c) a transmission selection circuit for selecting the set of transmission signal values associated with the received beacon signal as representative of the location of the mobile device; and

d) a transmitter coupled to the memory generating a modulated carrier signal representing the selected set of transmission signal values.

9. The network device of claim 8, wherein each of the plurality of location beacons transmits the beacon signal utilizing modulated illumination and the beacon detection circuit detects the modulated illumination.

10. The network device of claim 9, wherein the transmission signal values represents a network address of the remote computing device, a network address of the network device, a network protocol compliant preamble, and message data.

11. The network device of claim 10, wherein the transmission signal values represent a baseband transmission and the transmitter includes a D/A converter generating an analog baseband signal and an analog mixer for generating the modulated carrier.

12. The network device of claim 11, wherein the remote computing device activates at least one of an audio and visual alarm based on the network address of the network device and the predetermined message matching an alarm condition.

13. The network device of claim 12, wherein the at least one of an audio and visual alarm is activated on a mobile computing device and the remote computing device activates the alarm by sending a signal to the mobile computing device via the wireless network.

14. A method of reporting a location of a network device to a remote computing device, the method comprising:

a) receiving a beacon signal from one of a plurality of location beacons;

b) selecting a transmission frame corresponding to the received beacon signal from a plurality of transmission frames pre-stored in a memory as representative of the location of the mobile device; and

c) transmitting the selected transmission frame to the remote computing device.

15. The method of claim 14, wherein the beacon signal comprises modulated illumination.

16. The method of claim 15, the prestored transmission frame includes a sequence of transmission signal values representing a network address of the remote computing device, a network address of the network device, a network protocol compliant preamble, and message data.

17. The method of claim 16, wherein the transmission signal values represent a baseband transmission signal and the step of transmitting the selected transmission frame includes converting the signal values to an analog baseband signal and mixing the analog baseband signal up to carrier frequency.

18. The method of claim 17, further including a step of generating at least one of an audio and visual alarm based on the network address of the network device and the predetermined message matching an alarm condition.

19. The method of claim 18, wherein the step of generating at least one of an audio and a visual alarm includes activating an alarm on a mobile computing device by sending a signal to the mobile computing device via the wireless network.