Multicarrier packet communication method
Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.
1. A packet communication method in a multicarrier communications environment comprising:
determining, by a transceiver, a packet including a header portion and a data portion; and
transmitting, by the transceiver, the packet including the header portion and the data portion, wherein:
the header portion indicates one or more communications parameters used for the data portion of the packet, and
the data portion is used for communication of a number of data bytes at a data rate, and
wherein:
the header portion includes a legacy header portion, which is modulated on a first multicarrier symbol, the header portion containing a Rate field indicating a legacy data rate value and a Length field indicating a legacy number of data bytes,
the number of data bytes communicated in the data portion of the packet is different than the legacy number of data bytes indicated in the legacy header portion of the packet, and
the data rate used in the data portion of the packet is different than the legacy data rate indicated in the legacy header portion of the packet, and
wherein:
the header portion includes an extended rate header portion modulated on at least one additional multicarrier symbol,
the extended rate header portion includes at least one field indicating at least one actual communication parameter used for the data portion of the packet,
the extended header potion is not decodable by a legacy device, and
the Rate field and Length fields are used to defer transmission for a period of time at least corresponding to the duration of the packet, the packet including both the legacy header portion and the extended rate header portion.
2. The method of claim 1 , wherein the transceiver supports one or more of 802.11a and 802.11g.
3. The method of claim 1 , wherein the legacy device supports one or more of 802.11a and 802.11g.
4. The method of claim 1 , wherein the extended header portion indicates a bit allocation table.
5. The method of claim 1 , wherein the extended header portion indicates a cycle prefix length.
6. The method of claim 1 , wherein the extended header portion indicates a pilot tone allocation.
7. The method of claim 1 , wherein the Rate field and Length field are decodable by the legacy device and the data portion of the packet is not correctly decodable by the legacy device.
8. The method of claim 1 , wherein the Rate field and Length field are used by the legacy device to determine a duration of time.
9. The method of claim 1 , wherein the Rate field and Length field are used by the legacy device to set a Network Allocation Vector (NAV).
10. The method of claim 1 , wherein the transceiver is one or more of a general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element(s), an ASIC, a digital signal processor, a hard-wired electronic or logic circuit and a programmable logic device.
11. The method of claim 1 , wherein the legacy device is one or more of a general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element(s), an ASIC, a digital signal processor, a hard-wired electronic or logic circuit and a programmable logic device.
12. The method of claim 1 , wherein the transceiver is an access point.
13. A method of packet communication in a multicarrier communications environment comprising:
receiving, by a transceiver, a packet including a header portion and a data portion,
wherein:
the header portion indicates one or more communications parameters used for the data portion of the packet, and the data portion is used for communication of a number of data bytes at a data rate; and
the header portion includes a legacy header portion, which is modulated on a first multicarrier symbol, the header portion containing a Rate field indicating a legacy data rate value and a Length field indicating a legacy number of data bytes; and
decoding, by the transceiver, at least the legacy header portion,
wherein:
the number of data bytes communicated in the data portion of the packet is different than the legacy number of data bytes indicated in the legacy header portion of the packet, and the data rate used in the data portion of the packet is different than the legacy data rate indicated in the legacy header portion of the packet,
the header portion includes an extended rate header portion modulated on at least one additional multicarrier symbol,
the extended rate header portion includes at least one field indicating at least one actual communication parameter used for the data portion of the packet,
the extended header potion is not decodable by a legacy device, and
the Rate field and Length field are used to defer transmission for a period of time at least corresponding to the duration of the packet, the packet including both the legacy header portion and the extended rate header portion.
14. The method of claim 13 , wherein the transceiver supports one or more of 802.11a and 802.11g.
15. The method of claim 13 , wherein the legacy device supports one or more of 802.11a and 802.11g.
16. The method of claim 13 , wherein the extended header portion indicates a bit allocation table.
17. The method of claim 13 , wherein the extended header portion indicates a cycle prefix length.
18. The method of claim 13 , wherein the extended header portion indicates a pilot tone allocation.
19. The method of claim 13 , wherein the Rate field and Length field are decodable by the legacy device and the data portion of the packet is not correctly decodable by the legacy device.
20. The method of claim 13 , wherein the Rate field and Length field are used by the legacy device to determine a duration of time.
21. The method of claim 13 , wherein the Rate field and Length field are used by the legacy device to set a Network Allocation Vector (NAV).
22. The method of claim 13 , wherein the transceiver is one or more of a general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element(s), an ASIC, a digital signal processor, a hard-wired electronic or logic circuit and a programmable logic device.
23. The method of claim 13 , wherein the legacy device is one or more of a general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element(s), an ASIC, a digital signal processor, a hard-wired electronic or logic circuit and a programmable logic device.
24. The method of claim 13 , wherein the transceiver is an access point.