Patent Description:
Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for low-latency scheduling request configuration.

<CIT> discloses that a mechanism for Fast uplink Grant Acquisition may for example be based on the usage of an IP Header Sniffer, e.g. implemented in an entity of the mobile terminal which is doing MAC transport block header analysis and deciphering, to indicate arrival of a downlink TCP packet towards a layer <NUM> entity of the mobile terminal. The mobile terminal may thus send a scheduling request (e.g. a request for uplink communication resources) immediately to the radio access network without waiting for the feedback, i.e. a TCP ACK (acknowledgement) from the application processor of the mobile terminal.

<CIT> discloses that, by predicting a timing of generating a TCP ACK, a UE may transmit a second SR before the TCP ACK is notified from a higher layer of the UE to a lower layer of the UE.

<CIT> discloses a radio communication device comprising a communication unit configured to transmit and receive a signal in a first layer, data of a second layer which is an upper layer of the first layer, and delivery confirmation information for the data; and a control unit configured to enable the delivery confirmation information for the data of the second layer to be transmitted from the communication unit to another radio communication device using a first control channel of the first layer used to transmit control information.

In some aspects, a method of wireless communication, performed by a user equipment, includes receiving downlink data that is associated with triggering a feedback message; determining a flow identifier for the downlink data; transmitting, before receiving the feedback message for the downlink data at a component of the UE and based at least in part on the flow identifier , a scheduling request to request an allocation of a set of resources for transmitting the feedback message; and transmitting the feedback message in connection with the set of resources.

In some non-claimed aspects, a method of wireless communication, performed by a user equipment, may include receiving downlink data; determining a schedule of a set of uplink channel resources associated with a medium access control layer; altering a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources; and transmitting a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic.

In some aspects, a user equipment for wireless communication includes memory and one or more processors coupled to the memory. For example, the one or more processors may be operatively, electronically, communicatively, or otherwise coupled to the memory. The memory includes instructions executable by the one or more processors to cause the user equipment to receive downlink data that is associated with triggering a feedback message; determine a flow identifier for the downlink data; transmit, before receiving the feedback message for the downlink data at a component of the UE and based at least in part on the flow identifier, a scheduling request to request an allocation of a set of resources for transmitting the feedback message; and transmit the feedback message in connection with the set of resources.

In some non-claimed aspects, a user equipment for wireless communication may include memory and one or more processors coupled to the memory. For example, the one or more processors may be operatively, electronically, communicatively, or otherwise coupled to the memory. The memory may include instructions executable by the one or more processors to cause the user equipment to receive downlink data; determine a schedule of a set of uplink channel resources associated with a medium access control layer; alter a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources; and transmit a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic.

In some aspects, a non-transitory computer-readable medium stores one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a user equipment, cause the user equipment to receive downlink data that is associated with triggering a feedback message: determine a flow identifier for the downlink data; transmit, before receiving the feedback message for the downlink data at a component of the UE and based at least in part on the flow identifier, a scheduling request to request an allocation of a set of resources for transmitting the feedback message; and transmit the feedback message in connection with the set of resources.

In some non claimed aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a user equipment, may cause the user equipment to receive downlink data; determine a schedule of a set of uplink channel resources associated with a medium access control layer; alter a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources; and transmit a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic.

In some non claimed aspects, an apparatus for wireless communication may include means for receiving downlink data that is associated with triggering a feedback message; means for transmitting, before receiving the feedback message for the downlink data at a component of the UE , a scheduling request to request an allocation of a set of resources for transmitting the feedback message; and means for transmitting the feedback message in connection with the set of resources.

In some non claimed aspects, an apparatus for wireless communication may include means for receiving downlink data; means for determining a schedule of a set of uplink channel resources associated with a medium access control layer; means for altering a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources; and means for transmitting a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic.

Various aspects of the disclosure are described hereinafter with reference to the accompanying drawings. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with low-latency scheduling request configuration, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. In some aspects, memory <NUM> and/or memory <NUM> may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station <NUM> and/or the UE <NUM>, may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like.

In some aspects, UE <NUM> may include means for receiving downlink data that is associated with triggering a feedback message, means for transmitting, before receiving the feedback message for the downlink data at a component of the UE , a scheduling request to request an allocation of a set of resources for transmitting the feedback message, means for transmitting the feedback message in connection with the set of resources, and/or the like. In some aspects, UE <NUM> may include means for receiving downlink data, means for determining a schedule of a set of uplink channel resources associated with a medium access control layer, means for altering a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources, means for transmitting a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic, and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>, such as controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, and/or the like.

In some communications systems, communication resources may be allocated at a mini-slot granularity to enable reduced latency relative to full-slot granularity allocations. In such a communication system, a UE or a BS may transmit information using one or more symbols. When using transmission control protocol (TCP) for transmission in such a communication system, a throughput may be based at least in part on a latency that is achieved in the communication system. As a result, reducing a latency may cause an improvement in a TCP throughput.

A modem of a UE may receive TCP data (e.g., in a physical downlink shared channel (PDSCH)) on a downlink and may provide the TCP data to a stack of a host of the UE for processing. The UE (e.g., the host of the UE) may process the TCP data and may generate a feedback message (e.g., a TCP acknowledgement). The host may provide the feedback message to the modem and the UE may transmit the feedback message to the BS. The BS may route the feedback message to a TCP end point, which may use the feedback message for ensuring data reliability, enabling congestion control, and/or the like. To transmit the feedback message, the UE may transmit a scheduling request (SR) using physical uplink control channel (PUCCH) resources, receive a response (e.g., a physical downlink control channel (PDCCH) with an uplink grant) identifying one or more resources (e.g., one or more physical uplink shared channel (PUSCH) resources) for transmitting the feedback message, and may transmit the feedback messages using the one or more resources. However, a delay in waiting for available PUCCH resources to transmit the scheduling request as well as a delay in waiting to receive and use the allocation of PUSCH resources may result in excessive latency for TCP communication. This may result in a loss of throughput for TCP communication.

Some aspects described herein enable low-latency communication. For example, when a UE receives TCP data, on a downlink, that the UE is to acknowledge on an uplink, the UE may preemptively transmit a scheduling request (e.g., before the host has processed the TCP data and generated a feedback message) to a BS. In this case, the UE may receive information identifying an allocation of uplink resources for transmitting the feedback message at approximately the same time that the feedback message is ready for transmission. As a result, a TCP end point and the UE reduce a round trip time latency in TCP communications. Additionally, or alternatively, a UE- hosted modem data mover may synchronize data delivery of uplink traffic from a host to a modem (Data layer) with the modem's access stratum occasions to transmit uplink traffic. For example, the UE may use information regarding uplink traffic from a medium access control (MAC) layer to alter a behavior of uplink traffic at a data layer. In this case, by altering a behavior at the data layer, the UE may ensure that uplink traffic is available to enable use of a first available uplink transmission opportunity for transmitting a feedback message. In this way, the UE reduces a latency for transmitting the feedback message relative to maintaining static data layer behavior.

<FIG> is a diagram illustrating an example <NUM> of low-latency scheduling request configuration, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes a BS <NUM> and a UE <NUM> (e.g., that includes a modem <NUM> and a host <NUM>).

As further shown in <FIG>, and by reference numbers <NUM> and <NUM>, UE <NUM> may receive downlink data from TCP endpoint <NUM>. For example, UE <NUM> may receive a PDSCH conveying TCP data at modem <NUM> and may pass the TCP data to host <NUM> for processing.

As further shown in <FIG>, and by reference numbers <NUM>, <NUM>, and <NUM>, during processing of the TCP data, UE <NUM> may initiate a grant request. For example, concurrent with host <NUM> processing the TCP data or a data layer moving data from host <NUM> to modem <NUM>, modem <NUM> may transmit a PUCCH scheduling request to TCP endpoint <NUM>. In this case, modem <NUM> preemptively (e.g., predictively, based at least in part on a prediction of a receipt of a future TCP feedback message) transmits the PUCCH scheduling request (e.g., before a TCP feedback message generated by host <NUM> is available to modem <NUM>). In this case, the TCP ACK <NUM> is available in modem <NUM> shortly before an opportunity to transmit the TCP ACK (e.g., at <NUM>). Hence, latency experienced by TCP ACK <NUM> is small, thereby reducing a latency associated with obtaining uplink resources for transmitting the TCP feedback message.

In some aspects, UE <NUM> may enable predictive (preemptive) scheduling request transmission based at least in part on an aspect of the TCP data. For example, as described in more detail below, UE <NUM> may enable predictive scheduling for a particular priority class of TCP data, a quality of service (QoS) requirement for the TCP data, and/or the like. Additionally, or alternatively, UE <NUM> may enable predictive scheduling when the TCP data is in a low-throughput or slow-start state. Although some aspects are described herein in terms of TCP data, other types of data that trigger feedback messages are possible, such as QUIC protocol data (e.g., user datagram protocol (UDP) data), real-time transmission data (e.g., extended reality use cases), low-latency gaming data, streaming data, ping data, and/or the like. In some aspects, UE <NUM> may determine to enable predictive scheduling request transmission for a particular type of protocol. For example, UE <NUM> may perform predictive scheduling request transmission for QUIC protocol data, but may forgo performing predictive scheduling request transmission for other UDP data. In some aspects, UE <NUM> may perform predictive scheduling request transmission based on the timing of moving downlink data from modem <NUM> to host <NUM>.

In some aspects, UE <NUM> may determine a virtual data arrival time and may transmit the PUCCH scheduling request based at least in part on the virtual data arrival time. For example, UE <NUM> may determine a first amount of time between passing TCP data from modem <NUM> to host <NUM> and passing a TCP feedback message from host <NUM> to modem <NUM>. Additionally, or alternatively, UE <NUM> may determine a second amount of time between transmitting a scheduling request to TCP endpoint <NUM> to request resources and receiving a response including an uplink grant of resources. In this case, based at least in part on the first amount of time and/or the second amount of time, UE <NUM> may determine a virtual data arrival time at which to preemptively transmit the scheduling request such that the uplink transmission opportunity (e.g., a PUSCH transmission opportunity) associated with a grant occurs shortly after arrival of TCP ACK <NUM> in modem <NUM>.

In some aspects, UE <NUM> may determine the first amount of time, the second amount of time, and/or the like based at least in part on stored information regarding previous timings. For example, UE <NUM> may store information identifying the first amount of time for a set of previously received TCP data messages and may determine the first amount of time for a TCP data message based at least in part on an average for the first amount of time, a minimum for the first amount of time, a maximum for the first amount of time, and/or the like. Similarly, UE <NUM> may track the second amount of time on a per public land mobile network (PLMN) basis (e.g., per location, per tracking area cell, per cell identifier, per time of day, and/or the like), and may determine whether to preemptively transmit a scheduling request (or a time at which to preemptively transmit a scheduling request) based at least in part on tracking the second amount of time on a per PLMN basis. In some aspects, UE <NUM> may track the second amount of time based at least in part on an index of a PUCCH occasion that is to be used (PUCCH to grant delay may depend thereon, such as in a TDD configuration). In some aspects, UE <NUM> may determine whether a pre-scheduling mode is active for UE <NUM>, and may disable preemptive transmission of a scheduling request when the pre-scheduling mode is active.

In some aspects, UE <NUM> may determine whether to transmit the scheduling request preemptively. For example, UE <NUM> may determine whether to transmit the scheduling request preemptively based at least in part on a predicted arrival time of the TCP feedback message, the scheduling request, and/or the like. In this case, UE <NUM> may determine a latency savings from preemptively requesting the uplink resources and may transmit the scheduling request preemptively based at least in part on the latency savings satisfying a threshold. For example, when the first time (e.g., associated with receiving the TCP feedback) is less than a threshold (e.g., low-latency host <NUM> processing), UE <NUM> may forgo predictive scheduling request transmission.

In some aspects, UE <NUM> may determine whether to transmit the scheduling request preemptively based at least in part on a characteristic of the TCP data. For example, UE <NUM> may track a delay associated with generating a feedback message and/or receiving a grant on a per flow identifier basis (e.g., a per IP address, source address, target address, port address, protocol, connection, and/or the like basis). In this case, UE <NUM> may determine whether to preemptively transmit the scheduling request based at least in part on a latency savings for a flow identifier matching the TCP data. Additionally, or alternatively, UE <NUM> may determine whether to preemptively transmit the scheduling request based at least in part on a level of PDSCH traffic, a latency associated with host <NUM> (e.g., UE <NUM> may disable preemptive scheduling request transmission for a host <NUM> with a wide latency spread), and/or the like.

As further shown in <FIG>, and by reference numbers <NUM> and <NUM>, UE <NUM> may receive a grant of uplink resources and may generate a feedback message to transmit using the uplink resources. For example, based at least in part on preemptively transmitting the scheduling request, modem <NUM> may receive a PDCCH including an uplink grant from TCP endpoint <NUM> before receiving an indication to transmit a TCP acknowledgement from host <NUM>. Additionally, or alternatively, modem <NUM> may receive the uplink grant within a threshold amount of time of receiving the TCP acknowledgement. For example, based at least in part on preemptively transmitting the scheduling request, modem <NUM> may receive the uplink grant less than a threshold amount of time after receiving the TCP acknowledgement. In this way, UE <NUM> and TCP endpoint <NUM> reduce a latency to transmit the TCP acknowledgement, relative to requesting the uplink grant after receiving the TCP acknowledgement. Moreover, based at least in part on reducing the latency, UE <NUM> enables a discontinuous reception activity time to expire earlier (than if latency were longer), thereby reducing a utilization of power resources.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may transmit a TCP feedback message to TCP endpoint <NUM>. For example, UE <NUM> (e.g., modem <NUM>) may transmit a TCP acknowledgement to TCP endpoint <NUM> using PUSCH resources allocated in an uplink grant received from TCP endpoint <NUM>.

<FIG> is a diagram illustrating an example <NUM> of low-latency scheduling request configuration, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes a TCP endpoint <NUM> and a UE <NUM> (e.g., that includes a modem <NUM> and a host <NUM>).

As further shown in <FIG>, and by reference numbers <NUM>, <NUM>, and <NUM>, during processing of the TCP data, UE <NUM> may initiate a grant request. For example, concurrent with host <NUM> processing the TCP data, modem <NUM> may transmit a PUCCH scheduling request to TCP endpoint <NUM>.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may receive a grant of uplink resources. For example, based at least in part on preemptively transmitting the scheduling request, modem <NUM> may receive a PDCCH including an uplink grant from TCP endpoint <NUM> before receiving an indication to transmit a TCP acknowledgement from host <NUM>. In this case, the uplink grant may be smaller than the TCP acknowledgement from host <NUM>. For example, TCP endpoint <NUM> may grant fewer resources than are needed to transmit the TCP acknowledgement (e.g., all available TCP acknowledgments). In this case, as shown by reference number <NUM>, UE <NUM> may transmit a pseudo-acknowledgement using resources of the uplink grant. For example, UE <NUM> may transmit previously transmitted data, a retransmission of radio link control (RLC) data, data with a false logical channel identifier (LCID), MAC padding, and/or the like. In some aspects, UE <NUM> may include a request for another uplink grant in a PUSCH transmission using the resources of the uplink grant. For example, UE <NUM> may determine that a first uplink grant is less than a threshold size for transmitting the TCP acknowledgement and may include a request for a second uplink grant in resources of the first uplink grant. In some aspects, UE <NUM> may transmit a buffer status report (BSR) with the PUSCH.

As further shown in <FIG>, and by reference numbers <NUM>, <NUM>, and <NUM>, UE <NUM> may receive another uplink grant and may transmit the TCP feedback message to TCP endpoint <NUM> in resources of the other uplink grant. For example, UE <NUM> (e.g., modem <NUM>) may transmit a TCP acknowledgement to TCP endpoint <NUM> using PUSCH resources allocated in an uplink grant received from TCP endpoint <NUM>. In some aspects, UE <NUM> may consolidate a plurality of feedback messages in the resources of the other uplink grant. For example, when modem <NUM> receives another feedback message from host <NUM> before receiving the other uplink grant, modem <NUM> may consolidate the feedback message and the other feedback message for transmission using a single uplink grant.

As further shown in <FIG>, and by reference numbers <NUM> and <NUM>, during processing of the TCP data, UE <NUM> may initiate a grant request. For example, concurrent with host <NUM> processing the TCP data, modem <NUM> may transmit a PUCCH scheduling request to TCP endpoint <NUM>. In some aspects, UE <NUM> may include a delay indication in the grant request. For example, UE <NUM> may transmit the scheduling request and include information indicating a time at which TCP feedback information is expected. In this case, as shown by reference number <NUM>, TCP endpoint <NUM> may delay for a threshold period of time, in accordance with the delay indication, before transmitting a scheduling request. In some aspects, the delay indication may indicate a delay from receipt of the PUCCH at TCP endpoint <NUM> to transmission of a grant to UE <NUM>. Additionally, or alternatively, the delay indication may indicate a delay starting from transmission of the PUCCH, ending at receipt of the grant, and/or the like. In this way, TCP endpoint <NUM> may increase a scheduling request interval while still providing opportunities for UE <NUM> to transmit the scheduling request. In other words, TCP endpoint <NUM> may provide less frequent scheduling request transmission opportunities, but UE <NUM> may include the delay indication to enable use of an earlier scheduling request transmission opportunity (than shown in <FIG> and <FIG>), while still receiving the uplink resources at the same time as the TCP feedback message. In this way, TCP endpoint <NUM> and UE <NUM> avoid a mismatch whereby UE <NUM> transmits the scheduling request too early and the TCP feedback message is not ready when granted resources occur, or too late whereby the TCP feedback message is delayed until the grated resources occur. In this way, TCP endpoint <NUM> and UE <NUM> enable reduced uplink overhead associated with providing frequency scheduling request transmission opportunities.

As further shown in <FIG>, and by reference numbers <NUM> and <NUM>, UE <NUM> may receive a grant of uplink resources at approximately the same time as the TPC feedback message is ready for transmission. As shown by reference numbers <NUM> and <NUM>, UE <NUM> may transmit the TCP feedback message using the uplink resources. In some aspects, UE <NUM> may transmit another PUCCH scheduling request after transmitting the PUSCH resources (e.g., to prepare for acknowledging another PDSCH with TCP data).

<FIG> and <FIG> are diagrams illustrating examples <NUM>/<NUM>' of low-latency scheduling request configuration, in accordance with various aspects of the present disclosure. As shown in <FIG> and <FIG>, examples <NUM>/<NUM>' include a TCP endpoint <NUM> and a UE <NUM> (e.g., that includes a modem <NUM> and a host <NUM>).

As further shown in <FIG> and <FIG>, and by reference numbers <NUM> and <NUM>, UE <NUM> may receive downlink data from TCP endpoint <NUM>. For example, UE <NUM> may receive a PDSCH conveying TCP data at modem <NUM> and may pass the TCP data to host <NUM> for processing.

As further shown in <FIG>, and by reference numbers <NUM>, 656a, and <NUM>, during processing of the TCP data, a PUCCH scheduling request opportunity (or a configured grant or semi persistent scheduling (SPS) occurrence) may occur, resulting in a TCP feedback message being received at modem <NUM> after the PUCCH scheduling request opportunity. As a result, UE <NUM> delays until another scheduling request opportunity, as shown by reference numbers <NUM>, <NUM>, and <NUM>, before transmitting a scheduling request to request an uplink grant for transmitting the TCP feedback message. In contrast, as shown in <FIG>, and by reference number 656b, UE <NUM> may alter a behavior of a data layer of UE <NUM> to preemptively deliver the TCP feedback message from host <NUM> to modem <NUM> before the PUCCH scheduling request opportunity.

In this case, a medium access control (MAC) layer of UE <NUM> may identify, to a data layer of UE <NUM>, a set of parameters relating to an uplink channel to enable pulling of the TCP feedback message or other uplink latency sensitive traffic. For example, the MAC layer may identify a set of PUCCH scheduling request occasions, SPS occasions, an expiration of a periodic buffer status report (BSR) timer (e.g., indicating when UE <NUM> has an opportunity to indicate an updated size of an uplink buffer), an expected time at which the MAC layer will drain the uplink buffer (e.g., when the uplink buffer drains, TCP endpoint <NUM> may halt uplink grants causing latency in transmitting the TCP feedback message), and/or the like. In this case, based at least in part on the information regarding the uplink channel, UE <NUM> may alter a behavior of the data layer to preemptively deliver uplink traffic (e.g., the TCP feedback message) to the MAC layer, to enable the MAC layer to transmit the TCP feedback message at an earlier time. In some aspects, to achieve preemptive delivery, UE <NUM> may commit downlink data earlier than may have otherwise occurred, may commit the UL data earlier than may have otherwise occurred, may boost a CPU clock to accelerate processing time, may prevent entering a sleep state of one or more hardware components, and/or the like. In this way, UE <NUM> enables use of the PUCCH scheduling request opportunity indicated by reference number <NUM> for requesting an uplink grant, rather than the PUCCH scheduling request opportunity indicated by reference number <NUM> of <FIG>. In this way, UE <NUM> enables reduced latency for obtaining an uplink grant to transmit the TCP feedback message without predictive (preemptive) scheduling request transmission.

As further shown in <FIG> and <FIG>, and by reference numbers <NUM> and <NUM>, UE <NUM> may receive a grant of uplink resources. For example, as shown in <FIG> and <FIG>, by pulling the TCP acknowledgement message to modem <NUM> preemptively and using the PUCCH scheduling request opportunity of reference number <NUM>, rather than the TCP scheduling request opportunity of reference number <NUM>, UE <NUM> reduces a latency associated with transmitting the TCP acknowledgement message.

In some aspects, UE <NUM> may use information regarding a connected discontinuous reception (CDRX) mode to control when to have the TCP acknowledgement message available for transmission. For example, when a delay between a downlink message and uplink response traffic is greater than an inactivity timer for the CDRX mode, a medium access control (MAC) layer of UE <NUM> may indicate, to a data layer of UE <NUM>, that the CDRX mode is configured. Additionally, or alternatively, the MAC layer may indicate a period of time that a MAC entity will remain in an awake state, a period of time when the MAC entity will be in a sleep state, and a next period of time, after the sleep state, when the MAC entity will be in an awake state again. In this case, the data layer may configure a timing of the TCP acknowledgement message such that the TCP acknowledgement message arrives at modem <NUM> for transmission at a MAC awake time. In this case, to achieve time synchronization with the MAC awake time, UE <NUM> may pull the TCP acknowledgement message to modem <NUM> preemptively. Alternatively, UE <NUM> may delay the TCP acknowledgement message until a next on duration. In this way, UE <NUM> enables use of a CDRX mode with reduced power consumption relative to waking up the MAC entity when the TCP acknowledgement message is ready for transmission. In some aspects, the MAC entity may alter a value of a discontinuous reception (DRX) timer (e.g., a DRX inactivity timer) associated with the CDRX mode based at least in part on a latency associated with communication between mode <NUM> and host <NUM>.

Other examples may differ from what is described with respect to <FIG> and <FIG>.

As further shown in <FIG>, and by reference numbers <NUM> and <NUM>, host <NUM> of UE <NUM> may periodically process uplink traffic and push the uplink traffic to modem <NUM> of UE <NUM>. In this case, modem <NUM> receives the uplink traffic after a BSR update opportunity of reference number <NUM>. As a result, UE <NUM> delays reporting the uplink traffic to TCP endpoint <NUM> until a subsequent BSR update opportunity. In this case, as shown by reference number <NUM>, UE <NUM> may receive an uplink grant from TCP endpoint <NUM> that does not include resources for the uplink traffic, which may add delay until transmission.

In contrast, as shown in <FIG>, and by reference number <NUM>', in some aspects, UE <NUM> may preemptively provide the uplink traffic from host <NUM> to modem <NUM> preemptively, based at least in part on information indicating when the BSR update opportunity of reference number 756a is to occur. For example, based at least in part on layer <NUM> (L2) information regarding a radio bearer, a subscription identifier, a PUCCH scheduling request schedule, a buffer status report timer configuration, and/or the like, UE <NUM> may determine to alter a behavior of a data layer to pull uplink traffic from the data layer for transmission. In some aspects, a medium access control (MAC) layer of UE <NUM> may broadcast semi-static values for one or more parameters during a radio resource control (RRC) reconfiguration procedure to enable data layer alteration behavior. Additionally, or alternatively, UE <NUM> may use a request message to the MAC layer to cause the MAC layer to provide a response message with one or more values for one or more parameters. In some aspects, UE <NUM> (e.g., at L2) may determine whether to alter a data layer behavior based at least in part on an uplink allocation, a downlink allocation, a time of a first available uplink slot after expiration of a buffer status report timer, and/or the like.

In some aspects, UE <NUM> may define a time parameter representing an amount of time between providing a buffer status report layer from L2 to a first available uplink resource for transmitting a buffer status report. In this case, UE <NUM> may alter the behavior at the data layer when uplink traffic can be pulled to L2 before the first available uplink resource for transmitting the buffer status report. In some aspects, UE <NUM> (e.g., at L2) may provide a set of indications indicating whether an RRC reconfiguration invalidates previously provided parameter values, whether a buffer status report expiration value is to be invalidated, and/or the like.

In this case, UE <NUM> may report the uplink traffic in the BSR update opportunity indicated by reference number 756a. As a result, as shown by reference number <NUM>', UE <NUM> may receive an uplink grant from TCP endpoint <NUM> that includes resources for the uplink traffic. In this way, using dynamic data layer operation as shown in <FIG>, UE <NUM> reduces a latency for transmitting uplink traffic relative to static data layer operation as shown in <FIG>.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM> and/or the like) performs operations associated with low-latency scheduling request configuration.

As shown in <FIG>, process <NUM> includes receiving downlink data that is associated with triggering a feedback message (block <NUM>). The UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) receives downlink data that is associated with triggering a feedback message for transmission on an uplink, as described above. The UE determines a flow identifier for the downlink data.

As further shown in <FIG>, process <NUM> includes transmitting, before receiving the feedback message for the downlink data at a component of the UE and based at least in part on the flow identifier, a scheduling request to request an allocation of a set of resources for transmitting the feedback message (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit, before receiving (e.g., at a modem) the feedback message for the downlink data at a component of the UE , a scheduling request to request an allocation of a set of resources for transmitting the feedback message, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting the feedback message in connection with the set of resources (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit the feedback message in connection with the set of resources, as described above.

In a first aspect, transmitting the scheduling request includes transmitting the scheduling request based at least in part on the predicted arrival time of the feedback message.

In a second aspect, alone or in combination with the first aspect, the scheduling request is transmitted at a predicted scheduling request time, wherein the predicted scheduling request time is based at least in part on at least one of: a predicted time between receiving the downlink data and receiving the feedback message, or a predicted time between requesting the allocation of the set of resources and receiving a response granting the allocation of the set of resources.

In a third aspect, alone or in combination with one or more of the first and second aspects, transmitting the scheduling request includes transmitting the scheduling request before receiving a feedback message for the downlink data based at least in part on the flow identifier.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the flow identifier is based at least in part on at least one of: a source address, a destination address, a bearer identifier, a flow identifier, a quality of service identifier, a codepoint, a port, or a protocol.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes determining that the set of resources does not satisfy a threshold size for transmitting the feedback message; transmitting a buffer status report and pseudo-feedback message using the set of resources, wherein the buffer status is reporting includes information identifying a size corresponding to the feedback message; and transmitting the feedback message using another set of allocated resources.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, transmitting the scheduling request includes transmitting the scheduling request before receiving a feedback message for the downlink data based at least in part on the public land mobile network identifier.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, transmitting the scheduling request comprises: transmitting the scheduling request before receiving a feedback message for the downlink data based at least in part on determining that the pre-scheduling mode is active.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, transmitting the scheduling request comprises: transmitting the scheduling request before receiving a feedback message for the downlink data based at least in part on determining that processing the downlink data to generate the feedback message is associated with the threshold round-trip delay.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process <NUM> includes transmitting the scheduling request before receiving a feedback message for the downlink data based at least in part on a driver characteristic.

As shown in <FIG>, in some aspects, process <NUM> may include receiving downlink data (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive downlink data, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include determining a schedule of a set of uplink channel resources associated with a medium access control layer (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may determine a schedule of a set of uplink channel resources associated with a medium access control layer, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include altering a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may alter a behavior of data layer traffic based at least in part on a characteristic of the uplink channel resources, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit a feedback message in connection with one or more of the uplink channel resources and based at least in part on altering the behavior of the data layer traffic, as described above.

In a first aspect, the downlink data is associated with triggering the feedback message.

In a second aspect, alone or in combination with the first aspect, the set of uplink channel resources is associated with information identifying at least one of: a set of physical uplink control channel scheduling request occasions, one or more semi-persistent scheduling occasions, one or more configured grants, and/or the like available to a MAC layer, an expiration of a periodic buffer status reporting timer, or a predicted medium access control uplink buffer drain time.

In a third aspect, alone or in combination with one or more of the first and second aspects, altering the behavior of the data layer traffic includes altering the behavior of the data layer traffic based at least in part on identifying the transmission opportunity.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, altering the behavior of the data layer traffic includes causing downlink data to be delivered from the medium access control layer to a host before a scheduled delivery time.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, altering the behavior of the data layer traffic includes causing a change to a data processing time of the downlink data at a host.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, altering the behavior of the data layer traffic includes causing uplink data to be delivered from a host to the medium access control layer before a scheduled delivery time.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, altering the behavior of the data layer traffic includes altering the behavior of the data layer traffic based at least in part on at least one of: a timing of an uplink occasion, whether a low-latency request is active, a status of a transport layer connection, or a status of a bearer.

Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code - it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

Claim 1:
A method (<NUM>) of wireless communication performed by a user equipment (UE), comprising:
receiving (<NUM>) downlink data that is associated with triggering a feedback message;
determining a flow identifier for the downlink data; and
transmitting (<NUM>), before receiving the feedback message for the downlink data at a component of the UE and based at least in part on the flow identifier, a scheduling request to request an allocation of a set of resources for transmitting the feedback message.