Systems and methods for implementing protected access based on a null data packet in a wireless network

• US 9,749,975 B2
• Filed: 04/27/2015
• Issued: 08/29/2017
• Est. Priority Date: 04/30/2014
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Chu, Liwen, Wang, Lei, Zhang, Hongyuan, Lou, Hui-Ling, Sun, Yakun
• Primary Examiner(s): Ho, Chuong T
• Application Number:
  US14/697,128
• Publication Number:
  US 20150319782A1
• Time in Patent Office: 855 Days
• Field of Search: 370328, 370329, 370330
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

An access point including a generation module, a transceiver, and an acknowledgment module. The generation module is configured to generate a synchronization signal. The transceiver is configured to (i) transmit the synchronization signal to a station, (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station. The acknowledgment module is configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit. The synchronization signal or the acknowledgment signal includes a null data packet frame. The null data packet frame includes a legacy signal field. The legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field. The transceiver is configured to transmit the acknowledgment signal to the station.

Claims

1. An access point comprising:

a generation circuit configured to generate a synchronization signal;

a transceiver configured to (i) transmit the synchronization signal to a station, and (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station; and

an acknowledgment circuit configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field and a non-legacy signal field, wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, wherein the legacy signal field or the non-legacy signal field indicates a remaining duration of the transmit opportunity period for the station, and

wherein the transceiver is configured to transmit the acknowledgment signal to the station.

2. The access point of claim 1, wherein the synchronization signal comprises the null data packet frame.

3. The access point of claim 1, wherein the non-legacy signal field has more than two orthogonal frequency division multiplexing symbols.

4. The access point of claim 1, further comprising a compression circuit, wherein the compression circuit is configured to compress the non-legacy signal field.

5. The access point of claim 1, wherein the non-legacy signal field indicates a length of the null data packet frame.

6. An access point comprising:

a generation circuit configured to generate a synchronization signal;

a transceiver configured to (i) transmit the synchronization signal to a station, and (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station; and

an acknowledgment circuit configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field and a non-legacy signal field,wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, wherein the non-legacy signal field has a variable length, and wherein the variable length is based on an amount or type of medium access control information in the non-legacy signal field, and

wherein the transceiver is configured to transmit the acknowledgment signal to the station.

7. An access point comprising:

a generation circuit configured to generate a synchronization signal;

a transceiver configured to (i) transmit the synchronization signal to a station, and (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station; and

an acknowledgment circuit configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field, wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, wherein the null data packet frame further comprises a first non-legacy signal field and a second non-legacy signal field, wherein the first non-legacy signal field indicates a length of the second non-legacy signal field, and

wherein the transceiver is configured to transmit the acknowledgment signal to the station.

8. An access point comprising:

a generation circuit configured to generate a synchronization signal;

a transceiver configured to (i) transmit the synchronization signal to a station, and (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station; and

an acknowledgment circuit configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field, wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, and wherein the null data packet frame further comprises a first non-legacy signal field and a second non-legacy signal field; and

a coding circuit configured to modulate and code the first non-legacy signal field with a different modulation and coding scheme than that used for the second non-legacy signal field.

9. The access point of claim 8, further comprising a medium access control circuit comprising the generation circuit, the acknowledgement circuit and the coding circuit.

10. The access point of claim 8, further comprising a medium access control circuit comprising the generation circuit, the acknowledgement circuit and the coding circuit.

11. A station comprising:

a transceiver configured to receive a synchronization signal from an access point; and

a generation circuit configured to generate a medium access control protocol data unit based on the synchronization signal,

wherein the transceiver is configured to (i) transmit the medium access control protocol data unit to the access point during a transmit opportunity period of the station, and (ii) receive an acknowledgment signal based on the transmission of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal comprises a null data packet frame, wherein the null data packet frame comprises a legacy signal field and a first non-legacy signal field, wherein the legacy signal field or the first non-legacy signal field indicates a remaining duration of the transmit opportunity period for the station, and wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field.

12. The station of claim 11, wherein the synchronization signal comprises the null data packet frame.

13. The station of claim 11, wherein:

the first non-legacy signal field has a variable length; and

the variable length is based on an amount or type of medium access control information in the non-legacy signal field.

14. The station of claim 11, wherein the first non-legacy signal field has more than two orthogonal frequency division multiplexing symbols.

15. The station of claim 11, wherein:

the null data packet frame comprises a second non-legacy signal field; and

the first non-legacy signal field indicates a length of the second non-legacy signal field.

16. The station of claim 11, further comprising a coding circuit, wherein:

the null data packet frame comprises a second non-legacy signal field; and

the coding circuit is configured to modulate and code the first non-legacy signal field with a different modulation and coding scheme than that used for the second non-legacy signal field.

17. The station of claim 16, further comprising a medium access control circuit comprising the generation circuit and the coding circuit.

18. The station of claim 11, further comprising a compression circuit, wherein the compression circuit is configured to compress the first non-legacy signal field.

19. The station of claim 18, further comprising a medium access control circuit comprising the generation circuit and the compression circuit.

20. The station of claim 11, wherein the first non-legacy signal field indicates a length of the null data packet frame.

21. A method of operating an access point, the method comprising:

generate synchronization signal;

transmitting via a transceiver the synchronization signal to a station;

receiving a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station;

generating an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field and a first non-legacy signal field, wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, and wherein the first non-legacy signal field has more than two orthogonal frequency division multiplexing symbols; and

transmitting via the transceiver the acknowledgment signal to the station.

22. The method of claim 21, wherein the synchronization signal comprises the null data packet frame.

23. The method of claim 21, wherein the legacy signal field or the first non-legacy signal field indicates a remaining duration of the transmit opportunity period for the station.

24. The method of claim 21, wherein:

the null data packet frame comprises a second non-legacy signal field; and

the first non-legacy signal field indicates (i) a length of the second non-legacy signal field, and (ii) a length of the null data packet frame.

25. The method of claim 21, further comprising:

modulating and coding the first non-legacy signal field with a different modulation and coding scheme than that used for a second non-legacy signal field, wherein the null data packet frame comprises the second non-legacy signal field; and

compressing the first non-legacy signal field or the second non-legacy signal field.

26. A method of operating a station, the method comprising:

receiving via a transceiver a synchronization signal from an access point;

generating a medium access control protocol data unit based on the synchronization signal;

transmitting via the transceiver the medium access control protocol data unit to the access point; and

receiving via the transceiver an acknowledgment signal based on the transmission of the medium access control protocol data unit,

wherein the synchronization signal or the acknowledgment signal comprises a null data packet frame, wherein the null data packet frame comprises a legacy signal field and a first non-legacy signal field, wherein the legacy signal field comprises a length of a portion of the null data packet frame subsequent to the legacy signal field, and wherein the non-legacy signal field has more than two orthogonal frequency division multiplexing symbols.

27. The method of claim 26, wherein the synchronization signal comprises the null data packet frame.

28. The method of claim 26, further comprising transmitting via the transceiver the medium access control protocol data unit during a transmit opportunity period of the station, wherein the legacy signal field or the first non-legacy signal field indicates a remaining duration of the transmit opportunity period for the station.

29. The method of claim 26, wherein:

the null data packet frame comprises a second non-legacy signal field; and

the first non-legacy signal field indicates (i) length of the second non-legacy signal field, and (ii) a length of the null data packet frame.

30. The method of claim 26, further comprising:

modulating and coding the first non-legacy signal field with a different modulation and coding scheme than that used for a second non-legacy signal field, wherein the null data packet frame comprises the second non-legacy signal field; and

compressing the first non-legacy signal field or the second non-legacy signal field.

31. An access point comprising:

a processor;

a memory configured to more software including instructions, which are executable by the processor and are configured to generate a synchronization signal; and

a transceiver configured to (i) transmit the synchronization signal to a station, (ii) receive a medium access control protocol data unit based on the synchronization signal during a transmit opportunity period for the station,

wherein the instructions are further configured to generate an acknowledgment signal based on the reception of the medium access control protocol data unit, wherein the synchronization signal or the acknowledgment signal includes a null data packet frame, wherein the null data packet frame comprises a legacy signal field, wherein the legacy signal field comprises a length of a remaining portion of a physical layer convergence protocol (PLCP) protocol data unit (PPDU) that is subsequent to the legacy signal field of the null data packet frame, and

wherein the transceiver is configured to transmit the acknowledgment signal to the station.