Apparatus and methods for addressable communication using voice-grade radios

• US 20100238911A1
• Filed: 06/27/2006
• Published: 09/23/2010
• Est. Priority Date: 06/28/2005
• Status: Active Grant

• Current Assignee: Worcester Polytechnic Institute
• Original Assignee: Worcester Polytechnic Institute
• Inventors: Matthews, James W., Navalekar, Abhijit, Michalson, William R.
• Granted Patent: US 8,284,711 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

The invention relates to methods and apparatus for conducting directed communication using voice-grade radios. The methods and apparatus can be used to form a packet-switched wireless network using legacy analog transceivers, providing, e.g., both data and voice-over-Internet Protocol communication.

Claims

1. A method of transmitting via a radio comprising:

obtaining data for transmission;

converting the data into packets having a destination network address;

encoding the packets in a plurality of orthogonal frequency division multiplexed tones, wherein the tones range in frequency from about 300 Hz to about 3,000 Hz;

modulating a carrier frequency with the encoded tones; and

transmitting the modulated carrier frequency as an RF signal.

2. The method of claim 1, wherein the data comprises voice.

3. The method of claim 2, wherein the data comprises voice over Internet protocol packets.

4. The method of claim 1, wherein wirelessly transmitting the tones comprises outputting the tones to a radio for transmission.

5. The method of claim 1, comprising:

receiving a plurality of orthogonal frequency division multiplexed tones, wherein the tones range in frequency from about 300 Hz to about 3,000 Hz; and

decoding data encoded in the received tones into packets.

6. The method of claim 5, comprising outputting the decoded data.

7. The method of claim 5, comprising driving a speaker based on the decoded data.

8. The method of claim 5, comprising:

determining the destination of the decoded packets;

determining a next-hop node to which to forward the packets; and

re-encoding the packets and transmitting the re-encoded data packets to the next-hop node using orthogonal frequency division multiplexed tones having frequencies ranging from about 300 Hz to about 3,000 Hz.

9. The method of claim 1, wherein encoding the packets comprises encoding the plurality of orthogonal frequency division multiplexed tones using quadrature amplitude modulation.

10. The method of claim 1, wherein receiving data for transmission comprises receiving an audio signal via a microphone.

11. The method of claim 1, wherein receiving data for transmission comprises receiving data via a wired communications link with a computer.

12. The method of claim 1, wherein encoding the packets comprises modulating the tones according to a quadrature amplitude modulation process.

13. An apparatus comprising:

a housing;

a data input incorporated into the housing for receiving data to transmit;

a radio interface incorporated in the housing for communicatively coupling the apparatus to a radio via a wire;

a processor disposed within the housing and in electrical communication with the data and the output configured for;

packetizing the received data, such that the each resultant packet includes a destination network address;

encoding the packets in a plurality of orthogonal frequency division multiplexed tones, wherein the tones range in frequency from about 300 Hz to about 3,000 Hz; and

outputting the encoded tones via the radio interface.

14. The apparatus of claim 13, wherein the processor is configured for:

receiving orthogonal frequency division multiplexed tones encoded with packets of data including a destination network address;

decoding the tones to recover the packets; and

determine the destination address of the packets.

15. The apparatus of claim 13, wherein the processor is configured for, in response to determining that the destination network address in one of the recovered packets matches a network address corresponding to the apparatus, outputting data in the recovered packet to a data output incorporated into the housing.

16. The apparatus of claim 15, wherein the data output comprises a speaker.

17. The apparatus of claim 15, wherein the data output comprises a digital data port for communicating the data in the recovered packet over a wire.

18. The apparatus of claim 13, wherein the processor is configured for, in response to determining that the destination network address in the decoded packet differs from a network address identifying the apparatus:

re-encoding the recovered packet in a plurality of orthogonal frequency division multiplexed tones, wherein the tones range in frequency from about 300 Hz to about 3,000 Hz ;

and outputting the re-encoded packet via the radio interface for rebroadcasting.

19. The apparatus of claim 13 comprising a user interface incorporated into the housing for accepting an identifier corresponding to the destination address.

20. The apparatus of claim 19, wherein the user interface comprises a keypad and a display.

21. The apparatus of claim 13, wherein the data input comprises a microphone.

23. The apparatus of claim 13, wherein the data input comprises an Ethernet port.

24. The apparatus of claim 13, comprising a radio having an input port for accepting analog signals having frequencies of less than about 3,000 Hz, wherein the radio is communicatively coupled to the housing by a wire connected at one end to the input port of the radio and at the other end to the radio interface incorporated into the housing.

25. The apparatus of claim 13, wherein encoding the data packets comprises modulating the tones according to a quadrature amplitude modulation process.

22. The apparatus of claim 22, comprising a vocoder.

26. A communications device comprising:

an FM transceiver;

a processor configured for;

receiving FM transmissions including a plurality of orthogonal frequency division multiplexed tones modulated on a first carrier frequency, wherein the tones encode data packets having a destination address and range in frequency from about 300 Hz to about 3,000 Hz;

decoding the tones to determine the destination address; and

transmitting the packet towards the destination address.

27. The communications device of claim 26, wherein the processor is configured for:

determining a second carrier frequency corresponding to the destination address;

modulating the tones on the second carrier frequency; and

broadcasting the tones modulated on the second carrier frequency.

28. The communication device of claim 26, wherein transmitting the packet towards the destination address comprises transmitting the packet over an Ethernet wire.

29. The communication device of claim 26, wherein the data packets comprises Internet Protocol Packets.

30. The communication device of claim 26, wherein the data packets comprise Voice Over Internet Protocol Packets.

31. The communication device of claim 26, comprising a routing table for routing packets among nodes in a wireless network.

32. The communication device of claim 26, wherein the tones encode data packets according to a quadrature amplitude modulation process.

33. The communication device of claim 26 comprising a memory for archiving data packets processed by the processor.

34. The communication device for claim 26 comprising a memory for storing received packets prior to retransmission of the received packets.

35. A wireless local area network comprising:

a plurality of nodes configured for transmitting digital data packets encoded in a plurality of orthogonal frequency division multiplexed tones having frequencies between about 300 Hz to about 3,000 Hz, wherein the tones are modulated on a first FM carrier frequency and the data packets include a destination address;

a router configured for receiving the plurality of modulated orthogonal frequency division multiplexed tones, determining the destination address, and retransmitting the data packets.

36. The wireless local area network of claim 35, wherein the router retransmits the data packets as tones modulated at a second FM carrier frequency.

37. The wireless local area network of claim 35, wherein the router retransmits the data packets as tones modulated at the first FM carrier frequency.

38. The wireless local area network of claim 35, wherein the router retransmits the data packets over a wired channel.

39. The wireless local area network of claim 35, wherein the router retransmits the data over an 802.11 link.

40. The wireless local area network of claim 35, wherein the data packets are encoded in the tones according to a quadrature amplitude modulation process.