METHOD AND APPARATUS FOR PROTECTING HIGH THROUGHPUT STATIONS

• US 20070076752A1
• Filed: 09/12/2006
• Published: 04/05/2007
• Est. Priority Date: 09/14/2005
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad, Chandra, Arty, Terry, Stephen, Levy, Joseph, Grandhi, Sudheer
• Granted Patent: US 8,750,932 B2
• Time in Patent Office: Days
• US Class Current: 370/466
• CPC Class Codes: H04L 1/0079 Formats for control data H04L1/16 takes precedence; training sequences H04L25/00 and H04L27/00
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A method and apparatus for protecting high throughput (HT) stations (STAs) are disclosed. In one embodiment, a physical layer (PHY) legacy preamble transmitted by one STA is decoded by another STA that does not use a legacy preamble. In another embodiment, one STA is identified by another STA by using bits in the preamble of a packet to indicate which PHY type will be used in the remaining portion of the packet. In yet another embodiment, one STA sends ready-to-send (RTS)/clear-to-send (CTS) or CTS-to-self messages for reserving a medium in the presence of another STA of a different type than the one STA. In yet another embodiment, an access point (AP) transmits a beacon or an association message including a capability information element (IE) that indicates operation or support for a legacy preamble, HT STA preambles and a medium access control (MAC) packet transmission with HT protection mechanisms.

Claims

1. A high throughput (HT) transmission method implemented in a wireless communication system including a first type of station (STA) and a second type of STA, the method comprising:

the first STA transmitting at least one HT physical layer (PHY) packet data unit (PPDU), the PPDU including an HT preamble and an HT PHY payload, the HT preamble including information associated with the HT PHY payload;

the second STA receiving the PPDU from the first STA; and

the second STA extracting the information associated with the HT PHY payload from the HT preamble without being able to decode the HT PHY payload.

2. The method of claim 1 wherein the HT PPDU transmitted by the first STA includes a legacy PHY preamble, the method further comprising:

the second STA setting a network allocation vector (NAV) timer for the transmission based on information included in the legacy PHY preamble.

3. The method of claim 1 wherein the HT PPDU transmitted by the first STA includes a legacy PHY preamble, the method further comprising:

the second STA setting a network allocation vector (NAV) timer for the transmission based on at least one bit included in the HT preamble.

4. A method as in claim 1 wherein the first and second STAs participate in a wireless communication, wherein PPDUs transmitted by the first STA are incompatible with the capabilities of the second STA.

5. The method of claim 1 further comprising:

the second STA identifying the first STA.

6. The method of claim 5 further comprising:

the second STA decoding the entire PPDU.

7. The method of claim 1 further comprising:

the first STA identifying the second STA.

8. The method of claim 1 wherein the second STA sends a request to an access point (AP) to send a (RTS)/clear-to-send (CTS) message or to provide CTS-to-self protection support for reserving a medium.

9. The method of claim 8 wherein the second STA is in the presence of at least one first STA in the system.

10. A method as in claim 8 wherein the RTS/CTS or the CTS-to-self protection support is indicated in a beacon transmitted by the AP.

11. A high throughput (HT) station (STA) comprising:

a transmitter for transmitting protected HT transmissions;

a processor for generating at least one HT physical layer (PHY) packet data unit (PPDU), the PPDU including an HT preamble and an HT PHY payload, the HT preamble including information associated with the HT PHY payload; and

a receiver for decoding legacy PHY preambles received from other HT STAs.

12. The HT STA of claim 11 wherein a network allocation vector (NAV) timer for the transmission is set based on information included in the legacy PHY preamble.

13. The HT STA of claim 11 wherein a network allocation vector (NAV) timer for the transmission is set based on at least one bit included in the HT preamble.

14. The HT STA of claim 11 wherein the receiver decodes both mixed-mode PPDUs and non-HT PPDUs.

15. The HT STA of claim 11 wherein the receiver decodes both Green Field mode PPDUs, mixed-mode PPDUs and non-HT format PPDUs.

16. A method of protecting high throughput (HT) transmissions, the method comprising:

a non-access point (non-AP) station (STA) initiating a transmit opportunity (TXOP) by transmitting a request signal including a ready-to-send (RTS) frame to an access point (AP); and

the AP responding to the non-AP STA with a response clear-to-send (CTS) frame.

17. The method of claim 16 wherein the non-AP STA and the AP use a CTS-to-self message for protecting HT transmissions.

18. An access point (AP) comprising:

a processor configured to generate an association message, wherein the association message includes a capability information element (IE) having a plurality of fields which indicate operation or support for a legacy preamble, high throughput (HT) station (STA) preambles and a medium access control (MAC) packet transmission with HT protection mechanisms;

an antenna; and

a transmitter electrically coupled to the processor and the antenna for transmitting the association message.

19. An access point (AP) comprising:

a processor configured to generate a beacon, wherein the beacon includes a capability information element (IE) having a plurality of fields which indicate operation or support for a legacy preamble, high throughput (HT) station (STA) preambles and a medium access control (MAC) packet transmission with HT protection mechanisms;

an antenna; and

a transmitter electrically coupled to the processor and the antenna for transmitting the beacon.