Method and apparatus for retrieving a transmission opportunity control in reverse direction grant

Abstract

Embodiments of the present invention disclose a method and an apparatus for retrieving transmission opportunity control in reverse direction grant, so that a conflict occurring between a case where an RD Initiator continues sending another frame to an RD Responder after retrieving TXOP control and a case where a terminal other than the RD Initiator sends a block acknowledgement to the RD Responder can be avoided. The method provided in the embodiments of the present invention includes: when an RD Initiator fails to correctly demodulate a frame sent by an RD Responder, retrieving, by the RD Initiator, TXOP control by using a PIFS if it is impossible for the RD Responder to enable an MU-MIMO mode, and retrieving, by the RD Initiator, the TXOP control by using a duration if it is possible for the RD Responder to enable the MU-MIMO mode, where the duration is longer than the PIFS.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 13 / 689,445, filed on Nov. 29, 2012, which is a continuation of International Patent Application No. PCT / CN2012 / 072698, filed on Mar. 21, 2012. The International Application claims priority to Chinese Patent Application No. 201110276060.2, filed on Sep. 16, 2011. The afore-mentioned patent applications are hereby incorporated by reference in their entireties.FIELD OF THE INVENTION[0002]The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for retrieving transmission opportunity control in reverse direction grant.BACKGROUND OF THE INVENTION[0003]A basic service set (BSS) is a basic element of a wireless local area network (WLAN). A BSS network is formed by stations (STA) that have certain association within a specific coverage area. One scenario of the association is that stations directly communicate w...

AI Technical Summary

Benefits of technology

[0010]Embodiments of the present invention provide a method and an apparatus for retrieving transmission opportunity control in reverse direction grant, so that a conflict occurring between a case where an RD Initiator continues sending another frame to an RD Responder after retrieving TXOP control and a case where a terminal other than the RD Initiator sends a block acknowledgement to the RD Responder can be avoided.

[0031]It can be seen from the foregoing technical solutions that, the embodiments of the present invention have the following advantages.

[0033]In another embodiment of the present invention, when an RD Initiator fails to correctly demodulate a very high throughput signaling in a frame sent by an RD responder, the RD Initiator retrieves TXOP control by using a duration if it is possible for the RD Responder to enable an MU-MIMO mode, where the duration is longer than a PIFS. Because the RD Initiator retrieves the TXOP control by using a duration that is longer than the PIFS, that is, within the duration that is longer than the PIFS, a terminal other than the RD Initiator sends a block acknowledgment to the RD Responder, and then the RD Responder continues sending a frame. In this case, the RD Initiator may intercept that a channel is in a busy state, and does not retrieve the TXOP control, thereby avoiding a conflict occurring between a case where the RD Initiator continues sending another frame to the RD Responder after retrieving the TXOP control and a case where the terminal other than the RD Initiator sends a block acknowledgement to the RD Responder.

[0035]When the RD Initiator satisfies one of the following conditions, the RD Initiator retrieves the TXOP control by using a duration that is longer than the PIFS. The following conditions are: The frame is a multi-user frame; and the value of the Partial AID in the very high throughput signaling A1 is different from the value of the Partial AID of the RD Initiator. Because the RD Initiator retrieves the TXOP control by using a duration that is longer than the PIFS, that is, within the duration that is longer than the PIFS, a terminal other than the RD Initiator sends a block acknowledgment to the RD Responder, and then the RD Responder continues sending a frame. In this case, the RD Initiator may intercept that a channel is in a busy state, and does not retrieve the TXOP control, thereby avoiding a conflict occurring between a case where the RD Initiator continues sending another frame to the RD Responder after retrieving the TXOP control and a case where the terminal other than the RD Initiator sends a block acknowledgement to the RD Responder.

Problems solved by technology

In the same BSS network, due to factors such as a distance and transmit power, one STA is incapable of detecting another STA that is far away from it.

That is, at the same time point, the STA1 sends another frame to the AP and the STA2 sends a BA to the AP, thereby resulting in a conflict.

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