Fast control messaging mechanism for use in wireless network communications
View Patent ↗In a wireless network according to embodiments of the present invention, fast control messaging frames are used to signal control information. A fast control messaging (“FCM”) frame includes MAC layer control bits in a PLCP header, obviating the need for a PSDU. These frames can be used in 802.11n wireless networks as well as in other suitable 802.11x networks as well as non-802.11x networks to exchange control information while significantly reducing network overhead. In some embodiments, some information that might have been conveyed to a receiver's MAC layer in a PSDU is conveyed by including that information is a PLCP header and having logic within the receiver's PHY layer processing to process that information and convey that information up to the receiver's MAC layer in a simulated PSDU or other method. The indicator of an FCM frame can be a bit in a PLCP header, a modification of a CRC field of the PLCP header, or other indicator. The medication of the CRC field of the PLCP header can be an inversion of the CRC field, a translation of the CRC field by a constant value, or both, or some other variation.
1. In a wireless network, a method of signaling comprising:
sending a Physical-Layer Convergence Procedure (PLCP) frame as a fast control messaging (FCM) frame including a PLCP preamble and a modified PLCP header with an FCM indication to signal that the PLCP frame is an FCM frame, the FCM indication providing instruction to a receiver of the PLCP frame that control data is to be extracted from the modified PLCP header and that the receiver is not to attempt to process a PLCP Service Data Unit (PSDU) following the PLCP header if such a PSDU is present in the PLCP frame.
2. The method of claim 1 , further comprising setting a bit of the PLCP header as the FCM indication.
3. The method of claim 1 , further comprising modifying a Cyclic Redundancy Check (CRC) field of the PLCP header as the FCM indication.
4. The method of claim 3 , wherein modifying the CRC field of the PLCP header comprises inverting the CRC field of the PLCP header.
5. The method of claim 3 , wherein modifying the CRC field of the PLCP header comprises translating the CRC field by a constant value.
6. The method of claim 3 , wherein modifying the CRC field of the PLCP header comprises translating an inversion of the CRC field by a constant value.
7. A communications device including a receiver for receiving signals from a wireless medium, the device comprising:
receiving circuitry that receives a signal from a transmitter via the wireless medium and converts the signal to a digital sequence;
physical (PHY) layer logic that processes the received digital sequence, including logic that detects a frame comprising a Physical-Layer Convergence Procedure (PLCP) preamble and a PLCP header and logic that detects whether the PLCP header includes an indicator that the frame is a fast control messaging frame;
control bit extraction logic that extracts control bits from the PLCP header and disregards a PLCP Service Data Unit (PSDU) following the PLCP header when the PHY layer logic detects the indicator, and that extracts control bits from a PSDU following the PLCP header when the PHY layer logic does not detect the indicator; and
media access control (MAC) layer logic for processing the extracted control bits when extracted by the control bit extraction logic.
8. The communications device of claim 7 , wherein the indicator is one bit of the PLCP header.
9. The communications device of claim 7 , wherein the indicator is a modification of a Cyclic Redundancy Check (CRC) field of the PLCP header.
10. The communications device of claim 9 , wherein the modification of the CRC field of the PLCP header is an inversion of the CRC field of the PLCP header.
11. The communications device of claim 9 , wherein the modification of the CRC field of the PLCP header is a translation of the CRC field by a constant value.
12. The communications device of claim 9 , wherein the modification of the CRC field of the PLCP header is a translation of an inversion of the CRC field by a constant value.
13. A computer-readable storage medium having stored thereon computer-executable instructions for receiving signals, the computer-executable instructions comprising:
a first code segment for receiving a Physical-Layer Convergence Procedure (PLCP) frame having at least a PLCP preamble and a PLCP header;
a second code segment for determining whether the PLCP header includes a fast control messaging (FCM) indication that identifies the PLCP frame as an FCM frame;
a third code segment for extracting control data from the PLCP header if it is determined that the PLCP header includes the FCM indication; and
a fourth code segment for extracting control data from a PLCP Service Data Unit (PSDU) following the PLCP header if it is determined that the PLCP header does not include the FCM indication.
14. The computer-readable storage medium of claim 13 , the computer-executable instructions further comprising a fifth code segment for recognizing a modified Cyclic Redundancy Check (CRC) field of the PLCP header as the FCM indication.
15. The computer-readable storage medium of claim 13 , the computer-executable instructions further comprising a fifth code segment for recognizing a bit in the PLCP header as the FCM indication.
16. A communications apparatus comprising:
means for sending a Physical-Layer Convergence Procedure (PLCP) frame as a fast control messaging (FCM) frame including a PLCP preamble and a modified PLCP header with an FCM indication to signal that the PLCP frame is an FCM frame, the FCM indication providing instruction to a receiver of the PLCP frame that control data is to be extracted from the modified PLCP header and that the receiver is not to attempt to process a PLCP Service Data Unit (PSDU) following the PLCP header if such a PSDU is present in the PLCP frame; and means for setting a bit of the PLCP header as the FCM indication.
17. The communications apparatus of claim 16 , further comprising means for modifying a Cyclic Redundancy Check (CRC) field of the PLCP header as the FCM indication.
18. The communications apparatus of claim 17 , wherein the means for modifying the CRC field comprises means for inverting the CRC field of the PLCP header.
19. The communications apparatus of claim 17 , wherein the means for modifying the CRC field comprises means for translating the CRC field by a constant value.