Low power radio frequency communication

• US 9,158,949 B2
• Filed: 03/06/2013
• Issued: 10/13/2015
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Duke University, Ricoh Company Limited
• Original Assignee: Duke University, Ricoh Company Limited
• Inventors: Gudan, Ken, Chemishkian, Sergey, Hull, Jonathan J., Reynolds, Matthew S.
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): MORTELL, JOHN F
• Application Number:
  US13/786,635
• Publication Number:
  US 20140085051A1
• Time in Patent Office: 951 Days
• Field of Search: 340/10.1
• US Class Current: 1/1
• CPC Class Codes: G06K 19/071 the source being a field other than an interrogation field, e.g. WLAN, cellular phone network
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/10158 methods and means used by the interrogation device for reliably powering the wireless record carriers using an electromagnetic interrogation field
• CPC Class Codes: G06K 7/10207 parameter settings related to power consumption of the interrogator
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: H04W 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method, system and tag for low power radio frequency communication is described. In one embodiment, the RF tag comprises: an access point comprising: a first antenna; a first radio coupled to the first antenna; a central processing unit coupled to the first radio; a backscatter adapter coupled to the access point via a wired communication interface, the backscatter adapter comprising a backscatter radio and a second antenna coupled to the backscatter radio for use in communicating with an RF tag in the network via backscatter.

Claims

1. An access point for use in a radio frequency (RF) tag sensor network in which RF tags communicate via backscatter, the access point comprising:

a first antenna;

a first radio coupled to the first antenna;

a central processing unit (CPU) coupled to the first radio;

a backscatter radio coupled to the first antenna and the CPU for use in communicating with an RF tag in the network via backscatter,

wherein, in response to a transmission from the access point, the access point receives a hybrid backscatter-Internet packet, and a destination Internet protocol (IP) address for the hybrid backscatter-Internet packet is computed dynamically at run time and set by the RF tag.

2. The access point defined in claim 1 further comprising a modulator coupled between the backscatter radio and the first antenna.

3. The access point defined in claim 2 wherein the modulator is operable to transmit energy and communication data from the access point to the RF tag.

4. The access point defined in claim 3 wherein the energy comprises continuous wave energy.

5. The access point defined in claim 3 wherein the communication data comprises tag wake-up codes.

6. The access point defined in claim 2 wherein the modulator coupled to the backscatter radio to transmit one selected from a group consisting of:

an acknowledgement or a command instruction.

7. The access point defined in claim 1 further comprising a demodulator coupled between the backscatter radio and the first antenna to receive a backscattered signal from the RF tag and demodulate the signal into a data stream.

8. The access point defined in claim 7 wherein the data stream comprises sensor data captured and transmitted via backscatter from the RF tag.

9. The access point defined in claim 1 wherein the first radio comprises an 802.11 radio.

10. The access point defined in claim 1 further comprising a wired connector coupled to the CPU for connecting to a network.

11. The access point defined in claim 1 further comprising a second antenna coupled to the CPU.

20. The access point defined in claim 1, wherein the destination Internet protocol (IP) address for the hybrid backscatter-Internet packet is included in the received hybrid backscatter-Internet packet.

12. An access point for use in a radio frequency (RF) tag sensor network in which RF tags communicate via backscatter, the access point comprising:

a first antenna;

a first radio coupled to the first antenna;

a central processing unit (CPU) coupled to the first radio;

a backscatter radio coupled to the first antenna and the CPU for use in communicating with an RF tag in the network via backscatter;

a modulator coupled between the backscatter radio and the first antenna, wherein the modulator is operable to transmit energy and communication data from the access point to the RF tag; and

a demodulator coupled between the backscatter radio and the first antenna to receive a backscattered signal from the RF tag and demodulate the signal into a data stream,

wherein, in response to a transmission from the access point, the access point receives a hybrid backscatter-Internet packet, and a destination Internet protocol (IP) address for the hybrid backscatter-Internet packet is computed dynamically at run time and set by the RF tag.

13. The access point defined in claim 12 wherein the energy comprises continuous wave energy.

14. The access point defined in claim 12 wherein the communication data comprises tag wake-up codes.

15. The access point defined in claim 12 wherein the modulator coupled to the backscatter radio to transmit one selected from a group consisting of:

an acknowledgement or a command instruction.

16. The access point defined in claim 12 wherein the data stream comprises sensor data captured and transmitted via backscatter from the RF tag.

17. The access point defined in claim 12 wherein the first radio comprises an 802.11 radio.

18. The access point defined in claim 12 further comprising a wired connector coupled to the CPU for connecting to a network.

19. The access point defined in claim 12 further comprising a second antenna coupled to the backscatter radio.