Sharing an EDCA TXOP with RTA traffic
A communication circuit and protocol for a wireless local area network (WLAN) using single EDCA and/or Multiple-User (MU) EDCA in which frames for Real Time Applications (RTA) can utilize shared Transmit Opportunities (TXOPs) to reduce transmission latencies. The protocol is configured in a number of ways to ensure communication fairness, such as by ensuring a minimum required channel resource is provided for transmitting frames from the primary AC during the TXOP. AP MLDs and non-AP MLDs are also supported and can exchange information on distinguishing traffic streams from other traffic streams having the same Traffic Identifier (TID), in determining which links to use for transmitting the traffic stream.
1. An apparatus for wireless communication in a network, the apparatus comprising:
(a) a wireless station (STA) operating as either an access point (AP) or a non-AP STA, is configured for wirelessly communicating packets which carry frames over a channel with other wireless stations (STAs), which are either APs or non-AP STAs, on a wireless local area network (WLAN) in which enhanced distributed channel access (EDCA) is applied to more than one Access Category (AC);
(b) a processor within said STA;
(c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and
(d) wherein said instructions, when executed by the processor, perform steps comprising:
(i) distinguishing real time application (RTA) traffic from non-RTA traffic using a low latency traffic stream (LLTS) operation to differentiate between an RTA traffic stream and other traffic;
(ii) a requesting STA establishing an LLTS setup by sending an LLTS request frame having an action field specifying: category, QoS action, dialog token and LLTS request element which includes an RTA specification element (TSPEC) indicating attributes for the RTA, which is sent from the requesting STA through its station management entity (SME) to its medium access control (MAC) sublayer management entity (MLME) communicating this request message to an MLME of a recipient STA which collects information from MLME-LLTS request message and sends this to a recipient STA which generates an MLME-LLTS indication message to its SME or the SME of its affiliated MLD; wherein an SME of the recipient STA processes the LLTS request and sends an MLME-LLTS response message comprising LLTS setup results to its MLME, wherein the MLME of the recipient sends an LLTS response frame to the requesting STA, which sends an MLME-LLTS confirmation message to its SME or the SME of its affiliated MLD; wherein in response to information received in these frames it can be determined if the LLTS setup has been successful or not;
(iii) obtaining a transmit opportunity (TXOP) of a primary AC including TXOP channel resources;
(iv) utilizing a remainder of the TXOP channel resources to transmit RTA frames, determined by the TSPEC element of the LLTS, from non-primary ACs even though there may be frames from the primary AC that have not been transmitted during the TXOP; and
(v) wherein said LLTS can be modified or terminated by the recipient STA at any time.
2. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising ensuring that a minimum required channel resource is available within a channel resource for transmitting frames from the primary AC during the TXOP.
3. The apparatus of claim 2 , wherein the STA, which is ensuring minimum required channel resource to transmit frames from the primary AC, can utilize the minimum required channel resource for TXOP sharing if all the frames from the primary AC have been transmitted.
4. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA setting no minimum required channel resource to transmit frames from the primary AC during the TXOP.
5. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA ensuring that a given minimum number of bytes from the primary AC are transmitted during the TXOP.
6. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA ensuring that a minimum of required channel time is provided for transmitting frames from the primary AC during the TXOP.
7. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA transmitting RTA frames from non-primary ACs even if no frame from the primary AC has been transmitted during the TXOP.
8. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA transmitting RTA frames from non-primary ACs during the TXOP only if all the RTA frames from the primary AC have been transmitted.
9. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA transmitting RTA frames from non-primary ACs of higher priority during the TXOP, before transmitting RTA frames from the primary AC.
10. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA transmitting RTA frames from the non-primary ACs of lower priority during the TXOP.
11. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA transmitting a MU PPDU packet whose length is determined by the transmission and/or latency requirement of RTA frames from the primary ACs.
12. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA limiting the time of TXOP sharing.
13. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA allowing transmitting of RTA frames from non-primary ACs earlier than frames from the primary AC, only if those RTA frames are expiring.
14. The apparatus of claim 1 , wherein said instructions when executed by the processor perform steps further comprising the STA obtaining a TXOP of the primary AC and sharing the TXOP with a non-primary AC of low priority.
15. A method of wireless communication in a network, the method comprising:
(a) communicating from a wireless station (STA) operating as either an access point (AP) or a non-AP STA over a channel with other wireless stations (STAs), which are either APs or non-AP STAs, on a wireless local area network (WLAN) in which enhanced distributed channel access (EDCA) is applied to more than one access category (AC);
(b) distinguishing real time application (RTA) traffic from non-RTA traffic by determining if a low latency traffic stream (LLTS) operation has been setup for the RTA traffic stream; wherein an LLTS is setup through a communication between an LLTS requesting STA to a recipient STA, with the requesting STA sending an LLTS request, which includes an RTA specification element (TSPEC) indicating attributes for the RTA, through its station management entity (SME) and its MAC sublayer management entity (MLME) to a recipient station, which upon accepting the request the LLTS setup is established;
(c) obtaining a transmit opportunity (TXOP) of a primary AC;
(d) utilizing a remainder of the channel resource to transmit RTA frames, determined by the TSPEC element of the LLTS, from non-primary ACs even when there are frames from the primary AC that have not been transmitted during the TXOP; and
(e) wherein said LLTS can be modified or terminated by the recipient STA at any time.