Systems and methods for prioritizing bi-directional traffic flows

Abstract

Systems and methods are provided for synchronizing uplink (UL) and downlink (DL) traffic. In particular, frames associated with Quality of Service (QoS}-sensitive traffic flows to be transmitted in a first direction are prioritized commensurate with frames to be transmitted in a second direction, different/opposite to that of the first direction. For example, UL traffic flows can be prioritized based on DL traffic flows, where the traffic flows belong to the same application flow, and vice versa, where DL traffic flows can be prioritized based on UL traffic flows for the same application flow. In this way, end-to-end QoS can be achieved.

What is claimed is: 
     
         1 . A method for scheduling uplink (UL) traffic to a wireless local area network (WLAN) device, comprising:
 identifying downlink (DL) traffic flows associated with each high-priority application flow of the WLAN device;   determining a status of an UL buffer of each station (STA) associated with each of the high-priority application flows;   sorting each STA based on priorities of each of the high-priority application flows; and   providing channel access in the UL to each sorted STA in a manner that is at least equivalent to the channel access provided to the identified DL traffic flows.   
     
     
         2 . The method of  claim 1 , wherein the WLAN device comprises a device capable of scheduling UL traffic. 
     
     
         3 . The method of  claim 1 , wherein the WLAN device comprises an access point. 
     
     
         4 . The method of  claim 1 , wherein deep packet inspection is performed on the WLAN device to identify the DL traffic flows. 
     
     
         5 . The method of  claim 1 , wherein determining the UL buffer status of STAs comprises performing buffer polling on each of the STAs in real-time at determined intervals to estimate UL queue-depths. 
     
     
         6 . The method of  claim 5 , wherein performing the buffer polling comprises appending a Buffer Status Report Poll (BSRP) trigger frame to a WLAN Physical Layer Protocol Data Unit (PPDU) sent on a channel in the DL direction. 
     
     
         7 . The method of  claim 6 , wherein the performance of the buffer polling occurs at a determined periodicity dependent upon each of the high-priority application flows associated with each of the STAs. 
     
     
         8 . The method of  claim 1 , further comprising determining an access category (AC) of UL transmissions corresponding to each UL buffer. 
     
     
         9 . The method of  claim 8 , further comprising specifying in a trigger frame transmitted to each sorted STA, a preferred AC field indicative of an AC or set of ACs from which each sorted STA can dequeue packets for UL transmission. 
     
     
         10 . The method of  claim 9 , wherein the AC or set of ACs is/are commensurate with an AC or set of ACs associated with each of the high-priority application flows. 
     
     
         11 . The method of  claim 9 , further comprising optimizing resource unit (RU) size assigned to each UL transmission. 
     
     
         12 . The method of  claim 11 , wherein the RU size associated with a sorted STA having the highest priority is maximized. 
     
     
         13 . The method of  claim 9 , further comprising determining a UL transmission mode according to which each UL transmission is transmitted. 
     
     
         14 . The method of  claim 13 , where the UL transmission mode comprises one of UL Multi-User, Multiple Input, Multiple Output (MU-MIMO) or UL Orthogonal Frequency Division Multiple Access (OFDMA) depending on a size of a UL queue-depth corresponding to the UL buffer of each sorted STA. 
     
     
         15 . The method of  claim 1 , wherein the channel access is provided in the UL more frequently to those of the sorted STAs having higher priority application flows. 
     
     
         16 . A method for scheduling traffic, comprising:
 identifying at a wireless local area network (WLAN) device, traffic flows in a first direction associated with one or more prioritized application flows;   determining, by the WLAN device, an access category associated with the identified traffic flows in the first direction; and   prioritizing, by the WLAN device, traffic flows of the one or more prioritized application flows in a second direction different than the first direction by adjusting the access category (AC) associated with the identified traffic flows in the second direction to be at least equal to an AC associated with the identified traffic flows in the first direction.   
     
     
         17 . The method of  claim 16 , wherein the first direction comprises an uplink (UL) direction from a wireless local area network (WLAN) device to stations (STAB) associated to the WLAN device, and wherein the second direction comprises a downlink (DL) direction. 
     
     
         18 . The method of  claim 16 , further comprising performing preferred DL scheduling for transmitting the traffic flows in the second direction. 
     
     
         19 . The method of  claim 16 , wherein the adjusting of the AC comprises assigning an AC associated with the identified traffic flows in the second direction to be greater than the AC associated with the identified traffic flows in the first direction. 
     
     
         20 . The method of  claim 16 , wherein the WLAN device comprises an access point (AP).