Method and apparatus for active RFID network

• US 7,982,585 B2
• Filed: 02/28/2007
• Issued: 07/19/2011
• Est. Priority Date: 02/28/2007
• Status: Expired due to Fees

• Current Assignee: Li-Cheng R. Zai, Xinyu Zang
• Original Assignee: Li-Cheng R. Zai, Xinyu Zang
• Inventors: Zai, Li-Cheng Richard, Zang, Xinyu Harry
• Primary Examiner(s): Goins; Davetta W
• Assistant Examiner(s): GIRMA, FEKADESELASS
• Application Number:
  US11/712,641
• Publication Number:
  US 20080204193A1
• Time in Patent Office: 1,602 Days
• Field of Search: None
• US Class Current: 340/10.1
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 8/186 Processing of subscriber group data
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method and an apparatus for evaluating an expression embedded inside a communication packet received from an RFID (Radio Frequency Identification) interrogator device are described. The evaluation result may determine a selection with another RFID interrogator device. An RFID data packet may be sent to an RFID interrogator device based on a selection to be associated with the RFID interrogator. A task may be performed based on the evaluation as instructed by a remote RFID interrogator through a command included in the wireless communication packet.

Claims

1. A computer implemented method comprising:

establishing a first association via a wireless network with a first RFID (Radio Frequency Identification) interrogator device, the first association including a first network identifier of the first RFID interrogator device to enable communication with the first RFID interrogator device;

entering a sleep mode to conserve energy if no wireless communications packets are received from the first RFID interrogator device during a wake up period in a wake up mode with the first association established;

waking up from the sleep mode to the wake up mode, wherein a wireless communication packet is received via the first association from the first RFID interrogator device in the wake up mode, the wireless communication packet including a selection command and a second network identifier, the selection command indicating a selection by a second RFID interrogator device coupled to the wireless network;

establishing a second association with the second RFID interrogator device via the wireless network based on the selection, the second association including the second network identifier to enable communication with the second RFID interrogator device, wherein the first association with the first RFID interrogator device ends with the establishment of the second association, wherein the sleep mode is entered with the second association based on whether wireless communication packets are received from the second RFID interrogator device independent of the first RFID interrogator device; and

in response to receiving a broadcast wireless packet from the second RFID interrogator device in the wake up mode with the second association, sending an RFID data packet to the second RFID interrogator device via the second association.

2. The method of claim 1, wherein the sending comprises selectively communicating with the second RFID interrogator device directly.

3. The method of claim 1, wherein the wireless communication packet includes an expression and wherein the selection is determined based on an evaluation of the expression.

4. The method of claim 1, wherein the second RFID interrogator device is portable.

5. The method of claim 1, wherein the establishment of the second association comprises:

computing a measurement of a wireless signal associated with the wireless communication packet; and

comparing the measurement to a threshold value, wherein the comparison indicates a strength of the wireless signal for the establishment of the second association.

6. The method of claim 2, wherein the selectively communicating comprising:

storing an identification based on the selection with the second RFID interrogator device; and

sending a response data packet including the identification to the second RFID interrogator device.

7. The method of claim 1, wherein the wireless communication packet is a broadcast data packet.

8. The method of claim 6, wherein the identification is associated with a wireless network address of the second RFID interrogator device.

9. The method of claim 1, further comprising:

extracting a command from the wireless communication packet; and

performing a read/write task according to the command.

10. The method of claim 9, wherein the read/write task comprises storing a data associated with the wireless communication packet.

11. The method of claim 9, further comprising:

sending a polling packet to a first RFID interrogator repetitively based on a polling period; and

changing the polling period based on the performing the read/write task.

12. The method of claim 9, wherein the performing comprises:

reading a value from a storage according to a data associated with the communication packet; and

sending a response data packet to the second RFID interrogator, the response data packet including the identification and the value.

13. A computer implemented method comprising:

in response to receiving a first data packet wirelessly from a first wireless device, determining if the first wireless device is an interrogator device having a first association established with a second wireless device, the first association to enable communication between the first and second wireless devices, wherein the second wireless device enters a sleep mode to conserve energy if no wireless communications packets are received from the first wireless device during a wake up period in a wake up mode with the first association;

sending a second data packet including selection criteria wirelessly to the first wireless device if the first wireless device is the interrogator device, the selection criteria to select the second wireless device, wherein the second wireless device wakes up from the sleep mode to the wake up mode to receive the second data packet via the first association from the first wireless device;

establishing a second association with the second wireless device, based on the selection criteria, the second association to enable communication with the second wireless device, wherein the second association causes the second wireless device to end the first association with the first wireless device, wherein the second wireless device enters the sleep mode with the second association based on whether the second wireless device receives wireless communication packets via the second association independent of the first wireless device; and

collecting RFID (Radio Frequency Identification) data from a response data packet wirelessly received from the second wireless device in the wake up mode via the second association.

14. The method of claim 13, wherein the establishment of the second association comprises:

storing an identification received from the second wireless device, the identification identifying the second wireless device.

15. The method of claim 13, wherein the second wireless device is an RFID device associated with the first wireless device, the data packet being a dedicated data packet.

16. The method of claim 13, wherein the collecting comprises:

computing a measurement of a wireless signal associated with the response data packet.

17. A wireless device system comprising:

a packet handler module to receive a wireless communication packet via a first association in a wireless network from a first RFID (Radio Frequency Identification) interrogator device, the wireless communication packet including a selection instruction with a network identifier identifying a second RFID interrogator device coupled to the wireless network, wherein the system enters a sleep mode to conserve energy if no wireless communication packets are received from the first RFID interrogator device during a wake up period in a wake up mode with the first association and wherein the system wakes up from the sleep mode to the wake up mode to receive the wireless communication packet;

a selection module to execute the selection instruction for establishing a second association with the second RFID interrogator device according to the wireless communication packet received from the first RFID interrogator device, the second association including the network identifier to enable communication with the second RFID interrogator, wherein the first association with the first RFID interrogator device ends with the establishment of the second association, wherein the sleep mode is entered with the second association based on whether wireless communication packets are received from the second RFID interrogator device independent of the first RFID interrogator device;

a transaction module to determine a selection with the second RFID interrogator device based on the execution;

a storage to store an identification according to the selection with the second RFID interrogator device; and

a task module coupled with the storage to perform read/write operations to the storage according to the selection.

18. The system of claim 17, further comprising

a signal measurement module to derive an indicator based on a wireless signal associated with the wireless communication packet, wherein the selection depends on the indicator.

19. The system of claim 18, wherein the indicator is a RSSI (Receive Signal Strength Indicator) indicator.

20. A machine-readable non-transitory medium having instructions therein, which when executed by a machine, causes the machine to perform a method, the method comprising:

establishing a first association via a wireless network with a first RFID (Radio Frequency Identification) interrogator device, the first association including a first network identifier of the first RFID interrogator device to enable communication with the first RFID interrogator device;

entering a sleep mode to conserve energy if no wireless communications packets are received from the first RFID interrogator device during a wake up period in a wake up mode with the first association established;

waking up from the sleep mode to the wake up mode, wherein a wireless communication packet is received via the first association from the first RFID interrogator device in the wake up mode, the wireless communication packet including a selection command and a second network identifier, the selection command indicating a selection by a second RFID interrogator device coupled to the wireless network;

establishing a second association with the second RFID interrogator device via the wireless network based on the selection, the second association including the second network identifier to enable communication with the second RFID interrogator device, wherein the first association with the first RFID interrogator device ends with the establishment of the second association, wherein the sleep mode is entered with the second association based on whether wireless communication packets are received from the second RFID interrogator device independent of the first RFID interrogator device; and

in response to receiving a broadcast wireless packet from the second RFID interrogator device in the wake up mode with the second association, sending an RFID data packet to the second RFID interrogator device via the second association.