Apparatus and methods for addressable communication using voice-grade radios

• US 8,284,711 B2
• Filed: 06/27/2006
• Issued: 10/09/2012
• Est. Priority Date: 06/28/2005
• Status: Active Grant

• Current Assignee: Worcester Polytechnic Institute
• Original Assignee: Worcester Polytechnic Institute
• Inventors: Michalson, William R., Matthews, James W., Navalekar, Abhijit
• Primary Examiner(s): Nawaz, Asad M
• Assistant Examiner(s): Chu, Wutchung
• Application Number:
  US11/476,281
• Publication Number:
  US 20100238911A1
• Time in Patent Office: 2,296 Days
• Field of Search: 370/338, 370/295, 370/310, 370/389, 370/392, 379/100.15, 379/100.17, 379/102.02, 379/272, 455/447, 455/462, 455/422.1, 455/432.2, 455/426.1, 455/74.1, 455/41.2, 455/77, 455/213, 455/277.1, 455/339
• US Class Current: 370/319
• 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 first packets having a destination network address;

encoding the first packets in a first plurality of orthogonal frequency division multiplexed (OFDM) tones, wherein the tones of the first plurality of OFDM tones are limited in frequency to a human speech range from about 300 Hz to about 3,000 Hz;

modulating a carrier frequency with the first encoded tones;

transmitting, via a voice grade radio, the modulated carrier frequency as a first Radio Frequency (RF) signal;

receiving, using the voice grade radio, a second plurality of OFDM tones limited in frequency to the human speech range, wherein the voice grade radio comprises a bandpass filter to exclude components of received signals with frequencies outside of the human speech range;

decoding data encoded in the received second plurality of OFDM tones into second packets;

determining a destination address of the decoded second packets;

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

re-encoding the second packets into third packets; and

retransmitting the third packets to the next-hop node using a third plurality of OFDM tones limited in frequency to the human speech range, wherein said retransmitting comprises;

encoding the third packets in the third plurality of OFDM tones limited in frequency to the human speech range;

modulating the carrier frequency with the third encoded tones; and

transmitting the modulated carrier frequency as a second 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, comprising outputting the decoded data.

5. The method of claim 1, comprising driving a speaker based on the decoded data.

6. The method of claim 1, wherein encoding the first packets comprises encoding the first plurality of OFDM tones using quadrature amplitude modulation.

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

8. The method of claim 1, wherein obtaining data for transmission comprises receiving data at the voice grade radio via a wired communications link with a computer.

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

10. A voice grade radio apparatus comprising:

a housing;

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

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

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

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

encoding the first packets in a first plurality of orthogonal frequency division multiplexed (OFDM) tones, wherein the tones are limited in frequency to a human speech range from about 300 Hz to about 3,000 Hz;

outputting the encoded first tones via the voice grade radio interface;

decoding data encoded in a received second plurality of OFDM tones into second packets, wherein the received second plurality of OFDM tones is limited in frequency to the human speech range, and wherein the voice grade radio comprises a bandpass filter to exclude components of received signals with frequencies outside of the human speech range;

determining a destination address of the decoded second packets;

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

re-encoding the second packets into third packets; and

retransmitting the third packets to the next-hop node using a third plurality of OFDM tones limited in frequency to the human speech range, wherein said retransmitting comprises;

encoding the third packets in the third plurality of OFDM tones limited in frequency to the human speech range; and

outputting the third plurality of OFDM tones via the voice grade radio interface.

11. The apparatus of claim 10, wherein the processor is configured for, in response to determining that the destination network address in one of the decoded packets matches a network address corresponding to the apparatus, outputting data in the decoded packet to a data output incorporated into the housing.

12. The apparatus of claim 11, wherein the data output comprises a speaker.

13. The apparatus of claim 11, wherein the data output comprises a digital data port for communicating the data in the decoded packet over a wire.

14. The apparatus of claim 10 comprising a user interface incorporated into the housing for accepting an identifier corresponding to the destination address.

15. The apparatus of claim 14, wherein the user interface comprises a keypad and a display.

16. The apparatus of claim 10, wherein the data input comprises a microphone.

17. The apparatus of claim 10, comprising a vocoder.

18. The apparatus of claim 10, wherein the data input comprises an Ethernet port.

19. The apparatus of claim 10, comprising a radio having an input port for accepting analog signals having frequencies limited to 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.

20. The apparatus of claim 10, wherein encoding the data packets comprises modulating the tones according to a quadrature amplitude modulation process.

21. A communications device comprising:

a voice grade FM transceiver comprising a bandpass filter to exclude components of received signals with frequencies outside of a human speech range from about 300 Hz to about 3,000 Hz; and

a processor configured for;

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

decoding data encoded in the received first plurality of OFDM tones into the first packets;

determining the destination address of the decoded first packets;

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

re-encoding the first packets into second packets; and

retransmitting the second packets to the next-hop node using a second plurality of OFDM tones limited in frequency to the human speech range, wherein said retransmitting comprises;

encoding the second packets in the second plurality of OFDM tones limited in frequency to the human speech range, and

transmitting the second plurality of OFDM tones to the next-hop node.

22. The communications device of claim 21, wherein the processor is configured for:

determining a second carrier frequency corresponding to the destination address;

modulating the second tones on the second carrier frequency; and

broadcasting the second tones modulated on the second carrier frequency.

23. The communication device of claim 21, wherein retransmitting the second packets comprises transmitting the packets over an Ethernet wire.

24. The communication device of claim 21, wherein the first data packets comprise Internet Protocol Packets.

25. The communication device of claim 21, wherein the first data packets comprise Voice Over Internet Protocol Packets.

26. The communication device of claim 21, comprising a routing table for routing packets among nodes in a wireless network.

27. The communication device of claim 21, wherein the first tones encode data packets according to a quadrature amplitude modulation process.

28. The communication device of claim 21 comprising a memory for archiving data packets processed by the processor.

29. The communication device for claim 21 comprising a memory for storing received packets prior to retransmission of the received packets.

30. A wireless local area network comprising:

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

a router configured for;

receiving the first plurality of modulated orthogonal frequency division multiplexed (OFDM) tones,

decoding data encoded in the received first plurality of OFDM tones into the first packets,

determining the destination address of the decoded first packets,

determining a next-hop node to which to forward the first packets,

re-encoding the first packets into second packets, and

retransmitting the second data packets to the next-hop node using a second plurality of OFDM tones limited in frequency to the human speech range, wherein said retransmitting comprises;

encoding the second packets in the second plurality of OFDM tones limited in frequency to the human speech range, and

transmitting the second plurality of OFDM tones to the next-hop node.

31. The wireless local area network of claim 30, wherein the router retransmits the second data packets as tones modulated at a second FM carrier frequency.

32. The wireless local area network of claim 30, wherein the router retransmits the second data packets as tones modulated at the first FM carrier frequency.

33. The wireless local area network of claim 30, wherein the router retransmits the second data packets over a wired channel.

34. The wireless local area network of claim 30, wherein the router retransmits the second data packets over an 802.11 link.

35. The wireless local area network of claim 30, wherein the first data packets are encoded in the tones according to a quadrature amplitude modulation process.