Wireless communication system with parallel polling

• US 5,025,486 A
• Filed: 12/09/1988
• Issued: 06/18/1991
• Est. Priority Date: 12/09/1988
• Status: Expired due to Fees

• Current Assignee: Dallas Semiconductor Corporation (Analog Devices, Inc.)
• Original Assignee: Dallas Semiconductor Corporation (Analog Devices, Inc.)
• Inventors: Klughart, Kevin M.
• Primary Examiner(s): Kuntz, Curtis
• Application Number:
  US07/282,406
• Time in Patent Office: 921 Days
• Field of Search: 455/54, 455/56, 455/67, 455/51, 340/825.52, 340/825.08, 340/825.5, 370/95.2
• US Class Current: 340/3.1
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system which can provide short-range wireless data communication between a base station and a portable low-power module. Each portable module has an identification field by which it can be addressed separately. The identification field (which is 64 bits long in the presently preferred embodiment) can be parallel polled: By commanding all modules within range to respond, the base station can see the 64-bit identification fields combined in what is almost a "wired-OR" fashion. That is, if any one of the portable modules within range is pulsing (reporting a "1" bit) in a given time window, the base station will see a pulse; the base station will see the absence of a pulse only if all of the modules within range are reporting a "0" bit (not pulsing). This can be used, for example, to implement combinatorial logic functions on all (or some subfields of) the 64-bit identification field.

Claims

1. A wireless communication system, comprising:

at least one base station, and a set of remote modules;

wherein said base station includes a first RF transmitter capable of operation at a first frequency, and a second RF receiver capable of operation at a second frequency;

and wherein each of said remote modules includes a first RF receiver capable of operation at said first frequency, and a second RF transmitter capable of operation at said second frequency;

and said first transmitter and said second receiver of said base station, and said second transmitter and said first receiver of said remote module, are connected so that said base station and said remote module can carry on data communications on said first and second frequencies, but only while in mutual proximity;

wherein said base station can broadcast a polling command, over said first frequency, to ascertain what remote modules are in proximity at a given moment;

whereupon, if a respective one of said modules happens to be in proximity to said base station and respective module will receive said poling command through said respective first receiver, and will respond to said polling command, throuyh said respective second transmitter thereof, with a response which includes an identification field;

and wherein at least a portion of said identification field contains bit positions which are individually, and not combinatorially or numerically, assigned to correspond to respective subsets of said set of remote modules;

and wherein said base station contains logic to decode response to said polling command, and to determine the presence of multiple ones of said subsets of said modules, if ones of said subsets simultaneously respond to said polling command.

2. The system of claim 1, wherein at least some ones of said bits of said subfield are specifically assigned to individual ones of said remote modules.

3. The system of claim 1, wherein some number N of said bit positions of said identification are combinatorially assigned to 2^N of said remote modules, and N is greater than two.

4. The system of claim 1, wherein at least one of said remote modules comprises an access control chip, which is connected to said serial data bus and which is connected to provide password protection for said memory.

5. The system of claim 1, wherein at least one of said remote modules comprises a microprocessor.

6. The system of claim 1, wherein said remote module weighs less than 10 ounces and has a total volume of less than 10 cubic inches.

7. The system of claim 1, wherein said remote module is hand-portable.

8. The system of claim 1, wherein said remote module further comprises a memory controller chip, which is connected to provide an interface to an array of memory cells.

9. The system of claim 1, wherein said remote module further comprises multiple integrated circuits which can output a module identification through said second transmitter and can verify a password received from said first receiver.

10. The system of claim 1, wherein said remote module is battery-powered and portable.

11. The system of claim 1, wherein said first and second frequencies are much less than 100 GHz.

12. The system of claim 1, wherein said first frequency is less than 1 MHz, and said second frequency is greater than 30 MHz.

13. The system of claim 1, wherein said first frequency is much lower than said second frequency.

14. The system of claim 1, wherein said identification field includes more than 9 bit positions.

15. The system of claim 1, wherein said identification field includes more than 12 bit positions.

16. The system of claim 1, wherein said identification field includes more than 16 bit positions.

17. The system of claim 1, wherein said subfield of said identification field includes at least 6 bit positions.

18. The system of claim 1, wherein said subfield of said identification field includes at least 10 bit positions.

19. The system of claim 1, wherein said subfield of said identification field includes at least all but three of the bit positions of said identification field.

20. The system of claim 1, wherein said remote module is hand-portable.