Receiving Data in a Sensor Network

• US 20100157862A1
• Filed: 03/03/2010
• Published: 06/24/2010
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Radunovic, Bozidar, Truong, Hong Linh
• Granted Patent: US 8,130,669 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• 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 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A sensor network has a plurality of wireless sensors which transmit to an intermediate receiving device which relays data to a central server. A method is provided for receiving data packets at the intermediate receiving device from a plurality of the transmitting devices. Data packets are sensed on a communication medium at the receiving device and the total traffic intensity of data packets from the transmitting devices is estimated. A detection threshold for data packets is provided and adapted as a function of the total intensity. The receiving device receives data packets with a signal strength above the current detection threshold.

Claims

1. A method for receiving data from a plurality of transmitting devices at a receiving device, comprising:

detecting a first data packet with a first signal strength;

detecting a second data packet with a second signal strength;

comparing the first and second signal strengths; and

receiving the data packet with the stronger signal strength.

2. The method of claim 1, wherein the first and second data packets are detected in parallel.

3. The method of claim 1, wherein the method includes:

receiving a first data packet with a first signal strength;

detecting a second data packet with a second signal strength during the receiving process of the first data packet;

determining if the second signal strength is greater than the first signal strength; and

discontinuing the receipt of the first data packet and switching to the second data packet if the second signal strength is greater than the first signal strength.

4. The method of claim 1, wherein the method includes maintaining a list of active transmitting devices and the received signal strengths of the active transmitting devices.

5. The method of claim 1, wherein the method further includes multiplexing the data packet with the stronger signal strength responsive to comparing the first and second signal strengths.

6. The method of claim 1, wherein the method further includes sending the received the data packet with the stronger signal strength to a server.

7. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing reception of data packets from a plurality of transmitting devices at a receiving device, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 1.

8. A receiving device for receiving data packets from a plurality of transmitting devices, comprising:

first and second detection circuits for detecting the arrival of data packets;

a controller for comparing the signal strengths of detected data packets and selecting a data packet with the strongest signal strength; and

a receiving circuit for receiving the selected data packet.

9. The receiving device of claim 8, wherein a detection circuit detects the arrival of a second data packet with a greater signal strength than the signal strength of a first data packet in the process of being received by the receiving circuit, and the controller instructs the receiving circuit to discontinue the receipt of the first data packet and switch to the second data packet.

10. The receiving device of claim 8, wherein the controller includes a comparator for estimating and comparing the signal strengths of data packets and a selection multiplexer for forwarding the selected data packet to the receiving circuit.

11. The receiving device of claim 8, wherein the device includes at least one of:

a sensor for data packets on a communication medium at the receiving device, and

a list of active transmitting devices and their received signal strengths.

12. The receiving device of claim 8, wherein the data packets are detected in parallel.

13. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing reception of the data packets from a plurality of transmitting devices at a receiving device, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 8.

14. A sensor network comprising:

a plurality of wireless sensors having transmitters;

one or more receiving devices comprising;

first and second detection circuits for detecting the arrival of data packets transmitted from the plurality of wireless sensors;

a controller for comparing the signal strengths of detected data packets and selecting a data packet with the strongest signal strength; and

a receiving circuit for receiving the selected data packet.

15. The network of claim 14, wherein the one or more receiving devices include a transmitter.

16. The network of claim 14, wherein the network includes a server operative to receive data transmitted from the receiving circuit.

17. The network of claim 14, wherein the controller includes a comparator for estimating and comparing signal strengths of the data packets and a selection multiplexer for forwarding the selected data packet to the receiving circuit.

18. The network of claim 14, wherein the network operates on a pulse-based ultra-wide band physical layer.

19. The network of claim 14, wherein the data packets are detected in parallel.

20. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing reception of the data packets from a plurality of transmitting devices at a receiving device, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 14.