Patent Description:
<CIT> discloses that performance degradation can occur when a wireless device interrupts reception and transmission on a primary cell (PCell) to perform measurements on a secondary cell (SCell). The number and instances of such interruptions may be UE implementation specific. Therefore, an eNB may not be aware of an occurrence of such an interruption. Such interruptions may negatively interact with any link adaptation algorithm in a network node that uses HARQ ACK, NACK, or discontinuous transmission (DTX) as input for outer loop (OL) correction of channel estimates because the interruptions may appear as random HARQ DTX.

As defined by claim <NUM>, the invention provides a method of wireless communication at a user equipment, UE, comprising: receiving data from a first base station; performing a measurement of a downlink signal from a second base station based on a measurement configuration; and transmitting a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed. Preferred embodiments of the method of claim <NUM> are defined by claims <NUM> to <NUM>.

As defined by claim <NUM>, the invention provides an apparatus for wireless communication, comprising: means for receiving data from a first base station; means for performing a measurement of a downlink signal from a second base station based on a measurement configuration; and means for transmitting a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed. A preferred embodiment of the apparatus of claim <NUM> is defined by claim <NUM>.

As defined by claim <NUM>, the invention provides a computer-readable medium storing computer executable code which, when executed by a processor, causes the processor to perform a method according to any of claims <NUM> to <NUM>.

As defined by claim <NUM>, the invention provides a computer program comprising instructions which, when the computer program is executed by an apparatus for wireless communication, cause the apparatus to carry out a method according to any of claims <NUM> to <NUM>.

A base station may perform various radio resource management (RRM) procedures, such as handovers, radio resource control (RRC) reconfigurations, and data scheduling, in response to information provided by a UE. For example, the base station may perform outer loop link adaptation (OLLA) to improve a radio link with the UE in response to channel measurements performed by the UE, hybrid automatic repeat request (HARQ) feedback from the UE, or other information from the UE (e.g. radio link control (RLC) information and upper layer acknowledgments).

With respect to channel measurements, the base station may provide a measurement configuration to the UE (e.g. in an RRC reconfiguration message) that configures the UE to perform and report such measurements. For example, the measurement configuration may include one or more measurement objects indicating the frequency, time location, and subcarrier spacing of reference signals the UE is to measure (e.g. synchronization signal block (SSB), channel state information reference signal (CSI-RS), demodulation reference signal (DMRS), etc.), a reporting configuration for each measurement object (e.g. event triggered reporting or periodic reporting), measurement gaps indicating the time periods during which the UE may perform measurements, and other measurement criteria. Based on the measurement configuration, the UE may report intra-frequency <NUM> New Radio (NR) measurements, inter-frequency NR measurements, or inter-radio access technology (RAT) measurements of Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) frequencies (e.g. <NUM> Long Term Evolution (LTE)) to the base station. For instance, during a configured measurement gap, the UE connected to a serving cell on one frequency and in one RAT may measure a reference signal receive power (RSRP) of a configured reference signal in a neighbor cell on a same frequency, on a different frequency, or in a different RAT, and the UE may report the measurement to the base station when the measurement exceeds a threshold. Based on the measurements, the base station may adapt its scheduling grants to the UE or perform other RRM procedures.

Additionally, the measurement configuration may also support multi-radio dual connectivity (MR-DC). In MR-DC, two different nodes or base stations may provide resources and data to the UE, including a master node (MN) and a secondary node (SN). One type of MR-DC is E-UTRA-NR dual connectivity (EN-DC), in which the MN is an Evolved Node B (eNB in LTE) and the SN is a gNodeB (gNB in NR). Generally, in EN-DC, the eNB/MN sends RRC messages to the UE including the measurement configuration, while the gNB/SN sends data to the UE. The eNB/MN may also send data to the UE. The measurement configuration configured by the eNB/MN may include similar information as described above (e.g. measurement objects, reporting configuration, measurement gaps, and other criteria), and the UE may similarly report intra-frequency, inter-frequency, or inter-RAT measurements to the eNB/MN or gNB/SN based on the measurement configuration. For example, during a configured measurement gap, the UE connected to a serving eNB and gNB in EN-DC may measure an RSRP of a configured reference signal in a neighbor cell, and the UE may report the measurement to the serving eNB or gNB when the measurement exceeds a threshold. Based on the measurements, the eNB/MN or gNB/SN may adapt its scheduling grants to the UE or perform other RRM procedures.

Generally, a UE may not be able to measure a target carrier frequency in a neighbor cell simultaneously while transmitting or receiving on a serving cell. Thus, to enable the UE to perform such measurements, the base station (for example, the eNB/MN in EN-DC) may configure measurement gaps for the UE. During a measurement gap, the UE may retune its antennas to the frequency or RAT of the neighbor cell, perform measurements in the neighbor cell, and then retune its antennas back to the serving cell. The UE may repeat the measurement process periodically during each configured measurement gap.

However, in some cases while a UE is performing measurements during a configured measurement gap, a serving base station may still send scheduling grants to the UE. For example, in EN-DC, a lack of measurement gap coordination may exist between the eNB/MN providing the measurement configuration and the gNB/SN providing scheduling grants for data. As a result, the gNB/SN may transmit scheduling grants to the UE during the measurement gaps. As the UE is unable to receive the grants since the UE has tuned out from the gNB/SN to perform measurements during these periods of time, the UE may not report HARQ feedback to the base station acknowledging (or not acknowledging) the scheduling grants. Consequently, the base station may inaccurately determine from the lack of HARQ feedback that the UE is currently in a discontinuous reception (DRX) mode, and thus the base station may refrain from further transmitting grants for a period of time. Generally in DRX, the UE monitors the radio channel periodically for downlink data during an "on" duration and powers down most of its circuitry to save battery life during an "off" duration, and therefore the base station typically transmits data to the UE during the on duration while refraining from transmitting data to the UE during the off duration to save resources. Accordingly, the base station may refrain from transmitting scheduling grants to the UE for a period of time based on the incorrect assumption that the UE is in the off duration, even though the UE may have completed its measurements, has retuned back to the serving gNB/SN, and is in the on duration during this period of time. Thus, data transmissions to the UE may be inefficiently stalled, resulting in reduced data throughput.

To prevent this data stalling from occurring in such cases, the UE may transmit a scheduling request (SR) to the serving base station after performing a measurement based on the measurement configuration. The SR may inform the serving base station that the UE is not in the DRX off duration and currently has data to transmit to the base station. For example, to initiate the SR procedure, the UE may trigger a buffer status report (BSR) (e.g. a regular BSR) in response to determining a decrease in an amount of data received from the serving base station or in an amount of uplink grants received from the serving base station following a measurement gap. To identify whether such decrease has occurred, the UE may first determine whether a threshold amount of data and/or a threshold amount of uplink grants, e.g. x bytes of data and/or z number of grants, was received from the base station within a threshold amount of time prior to performing the measurement, e.g. y ms before the measurement gap, where x, y, and z are preconfigured thresholds. If so, then the UE may next determine whether the UE tuned to a different frequency, RAT, or cell (relative to a frequency, RAT, or cell of the serving base station) to perform a measurement during the measurement gap. Afterwards, the UE may determine whether another threshold amount of data and/or another threshold amount of uplink grants, e.g. a bytes of data and/or c number of grants, was not received from the base station within another threshold amount of time after performing the measurement, e.g. b ms after the measurement gap, where a, b, and c are preconfigured thresholds and may respectively be the same as or different than x, y, and z. If so, the UE may determine that a decrease in received data or received grants has occurred since the measurement gap, and the UE may transmit SR accordingly to prevent the serving base station from incorrectly determining the UE to be in the DRX off duration. That is, if the UE determines that a threshold amount of data and/or a threshold amount of uplink grants was received within a threshold amount of time prior to the measurement gap, but that the same or a different threshold amount of data and/or uplink grants was not received within a threshold amount of time after the measurement gap (e.g., the thresholds were met before the gap but not after the gap), the UE may conclude that a decrease in received data or received grants has occurred, and thus the UE may transmit the SR in response to this conclusion. Thus, data stalling may be prevented and data throughput may be improved.

The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations <NUM>, user equipment(s) (UE) <NUM>, an Evolved Packet Core (EPC) <NUM>, and another core network <NUM> (e.g., a <NUM> Core (5GC)).

The base stations <NUM> configured for <NUM> Long Term Evolution (LTE) (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC <NUM> through first backhaul links <NUM> (e.g., S1 interface). The base stations <NUM> configured for <NUM> New Radio (NR) (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network <NUM> through second backhaul links <NUM>. In addition to other functions, the base stations <NUM> may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, Multimedia Broadcast Multicast Service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages.

The base stations <NUM> / UEs <NUM> may use spectrum up to Y megahertz (MHz) (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction.

The wireless communications system may further include a Wi-Fi access point (AP) <NUM> in communication with Wi-Fi stations (STAs) <NUM> via communication links <NUM>, e.g., in a <NUM> gigahertz (GHz) unlicensed frequency spectrum or the like.

The EPC <NUM> may include a Mobility Management Entity (MME) <NUM>, other MMEs <NUM>, a Serving Gateway <NUM>, an MBMS Gateway <NUM>, a Broadcast Multicast Service Center (BM-SC) <NUM>, and a Packet Data Network (PDN) Gateway <NUM>.

Generally, the AMF <NUM> provides Quality of Service (QoS) flow and session management. All user IP packets are transferred through the UPF <NUM>. The IP Services <NUM> may include the Internet, an intranet, an IMS, a Packet Switch (PS) Streaming Service, and/or other IP services.

Referring again to <FIG>, in certain aspects, the UE <NUM> may include a measurement gap component <NUM> that is configured to receive data from a first base station, perform a measurement of a downlink signal from a second base station based on a measurement configuration, and transmit a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed.

Although the present disclosure may focus on <NUM> NR, the concepts and various aspects described herein may be applicable to other similar areas, such as LTE, LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Global System for Mobile communications (GSM), or other wireless/radio access technologies.

In the examples provided by <FIG>, the <NUM> NR frame structure is assumed to be TDD, with subframe <NUM> being configured with slot format <NUM> (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe <NUM> being configured with slot format <NUM> (with mostly UL).

A frame, e.g., of <NUM> milliseconds (ms), may be divided into <NUM> equally sized subframes (<NUM>). The symbols on DL may be cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM) (CP-OFDM) symbols. For slot configuration <NUM>, different numerologies µ <NUM> to <NUM> allow for <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> slots, respectively, per subframe. The subcarrier spacing may be equal to <NUM>µ * <NUM> kilohertz (kHz), where µ is the numerology <NUM> to <NUM>. <FIG> provide an example of slot configuration <NUM> with <NUM> symbols per slot and numerology µ=<NUM> with <NUM> slots per subframe. The slot duration is <NUM>, the subcarrier spacing is <NUM>, and the symbol duration is approximately <NUM>. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see <FIG>) that are frequency division multiplexed. Each BWP may have a particular numerology.

A PDCCH within one BWP may be referred to as a control resource set (CORESET). Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)).

The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) / non-acknowledgement (NACK) feedback.

At least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> may be configured to perform aspects in connection with measurement gap component <NUM> of <FIG>.

A base station may perform various RRM procedures, such as handovers, RRC reconfigurations, and data scheduling, in response to information provided by a UE. For example, the base station may perform OLLA to improve a radio link with the UE in response to channel measurements performed by the UE, HARQ feedback from the UE, or other information from the UE (e.g. RLC information and upper layer acknowledgments).

With respect to channel measurements, the base station may provide a measurement configuration to the UE (e.g. in an RRC reconfiguration message) that configures the UE to perform and report such measurements. For example, the measurement configuration may include one or more measurement objects indicating the frequency, time location, and subcarrier spacing of reference signals the UE is to measure (e.g. SSB, CSI-RS, DMRS, etc.), a reporting configuration for each measurement object (e.g. event triggered reporting or periodic reporting), measurement gaps indicating the time periods during which the UE may perform measurements, and other measurement criteria. Based on the measurement configuration, the UE may report intra-frequency NR measurements, inter-frequency NR measurements, or inter-RAT measurements of E-UTRA frequencies (e.g. LTE) to the base station. For instance, during a configured measurement gap, the UE connected to a serving cell on one frequency and in one RAT may measure an RSRP of a configured reference signal in a neighbor cell on a same frequency, on a different frequency, or in a different RAT, and the UE may report the measurement to the base station when the measurement exceeds a threshold. Based on the measurements, the base station may adapt its scheduling grants to the UE or perform other RRM procedures.

Additionally, the measurement configuration may also support MR-DC. In MR-DC, two different nodes or base stations may provide resources and data to the UE, including an MN and a SN. One type of MR-DC is EN-DC, in which the MN is an eNB (LTE) and the SN is a gNB (NR). Generally, in EN-DC, the eNB/MN sends RRC messages to the UE including the measurement configuration, while the gNB/SN sends data to the UE. The eNB/MN may also send data to the UE. The measurement configuration configured by the eNB/MN may include similar information as described above (e.g. measurement objects, reporting configuration, measurement gaps, and other criteria), and the UE may similarly report intra-frequency, inter-frequency, or inter-RAT measurements to the eNB/MN or gNB/SN based on the measurement configuration. For example, during a configured measurement gap, the UE connected to a serving eNB and gNB in EN-DC may measure an RSRP of a configured reference signal in a neighbor cell, and the UE may report the measurement to the serving eNB or gNB when the measurement exceeds a threshold. Based on the measurements, the eNB/MN or gNB/SN may adapt its scheduling grants to the UE or perform other RRM procedures.

<FIG> illustrates an example <NUM> of a measurement gap <NUM>. When the UE receives a measurement configuration from the base station, the measurement configuration may include a measurement gap configuration indicating a measurement gap length (e.g. <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc.), a measurement gap repetition periodicity (e.g. <NUM>, <NUM>, <NUM>, <NUM>, etc.), and other criteria. For instance, <FIG> illustrates an example where the base station configures the UE with a measurement gap length of <NUM> (e.g. <NUM> subframes) and a measurement repetition periodicity of <NUM> (e.g. occurring after every <NUM> frames), although different gap lengths and periodicities may be configured in other examples. During each measurement gap <NUM>, the UE may perform RF retuning to a different frequency, RAT, or cell, perform measurements, and then perform RF tuning back from the different frequency, RAT, or cell.

However, in some cases while a UE is performing measurements during a configured measurement gap, a serving base station may still send scheduling grants to the UE. For example, in EN-DC, a lack of measurement gap coordination may exist between the eNB/MN providing the measurement configuration and the gNB/SN providing scheduling grants for data. As a result, the gNB/SN may transmit scheduling grants to the UE during the measurement gaps. As the UE is unable to receive the grants since the UE has tuned out from the gNB/SN to perform measurements during these periods of time, the UE may not report HARQ feedback to the base station acknowledging (or not acknowledging) the scheduling grants. Consequently, the base station may inaccurately determine from the lack of HARQ feedback that the UE is currently in a DRX mode, and thus the base station may refrain from further transmitting grants for a period of time. Generally in DRX, the UE monitors the radio channel periodically for downlink data during an "on" duration and powers down most of its circuitry to save battery life during an "off" duration, and therefore the base station typically transmits data to the UE during the on duration while refraining from transmitting data to the UE during the off duration to save resources. Accordingly, the base station may refrain from transmitting scheduling grants to the UE for a period of time based on the incorrect assumption that the UE is in the off duration, even though the UE may have completed its measurements, has retuned back to the serving gNB/SN, and is in the on duration during this period of time. Thus, data transmissions to the UE may be inefficiently stalled, resulting in reduced data throughput.

<FIG> illustrates an example <NUM> of a UE <NUM> in communication with serving base stations in EN-DC, including an eNB <NUM> (MN) and a gNB <NUM> (SN). The eNB <NUM> and gNB <NUM> may be in respective serving cells A and B, respectively. The eNB <NUM> may provide a measurement configuration to the UE <NUM> (e.g. via RRC signaling) to perform intra-frequency, inter-frequency, or inter-RAT measurements of a reference signal from a neighbor base station <NUM> in a neighbor cell C. The measurement configuration may include a configured measurement occasion or measurement gap (e.g. measurement gap <NUM>) during which the UE <NUM> may periodically perform its measurements. At the beginning of the UE's DRX on duration, the gNB <NUM> may send reference signals (e.g. CSI-RS) and scheduling grants for downlink data, uplink data, or measurement reports (e.g. CSI reports). However, due to a lack of measurement gap coordination between the eNB <NUM> and gNB <NUM>, the gNB <NUM> may continue to send scheduling grants to the UE <NUM> while the UE is performing measurements during measurement gaps. As the UE <NUM> does not expect to receive data while performing its measurements, the UE may not send HARQ feedback to gNB <NUM>, causing the gNB to incorrectly determine the UE to be in the DRX off duration. As a result, the gNB <NUM> may stop transmitting scheduling grants to the UE, resulting in data stalling at least until after the UE experiences an actual DRX off duration and subsequent DRX on duration.

To prevent this data stalling from occurring in such cases, the UE may transmit a SR to the serving base station after performing a measurement based on the measurement configuration. The SR may inform the serving base station that the UE is not in the DRX off duration and currently has data to transmit to the base station. For example, to initiate the SR procedure, the UE may trigger a BSR (e.g. a regular BSR) in response to determining a decrease in an amount of data received from the serving base station and/or in an amount of uplink grants received from the serving base station following a measurement gap. To identify whether such decrease has occurred, the UE may first determine whether a threshold amount of data and/or a threshold amount of uplink grants, e.g. x bytes of data and/or z number of grants, was received from the base station within a threshold amount of time prior to performing the measurement, e.g. y ms before the measurement gap, where x, y, and z are preconfigured thresholds. For example, referring to <FIG> and <FIG>, the UE <NUM> may determine whether at least <NUM> KB of data (or some other threshold amount of data) or at least <NUM> uplink grants (or some other threshold number of grants) was received from gNB <NUM> (or eNB <NUM>) in the last <NUM> (or some other threshold amount of time) before one of the measurement gaps <NUM>. If so, then the UE may next determine whether the UE tuned to a different frequency, RAT, or cell (relative to a frequency, RAT, or cell of the serving base station) to perform a measurement during the measurement gap. For example, referring to <FIG> and <FIG>, the UE <NUM> may determine from the measurement configuration that the UE measured RSRP of an SSB, CSI-RS, or some other downlink signal of neighbor base station <NUM> during the same one of the measurement gaps <NUM>. If so, then the UE may determine whether another threshold amount of data and/or another threshold amount of uplink grants, e.g. a bytes of data and/or c number of grants, was not received from the base station within another threshold amount of time after performing the measurement, e.g. b ms after the measurement gap, where a, b, and c are preconfigured thresholds and may respectively be the same as or different than x, y, and z. For example, referring to <FIG> and <FIG>, the UE <NUM> may determine whether at least <NUM> KB of data (or some other threshold amount of data) or at least <NUM> uplink grants (or some other threshold number of grants) was not received from eNB <NUM> or gNB <NUM> in the last <NUM> (or some other threshold amount of time) after measurement gap <NUM>. If so, the UE may determine that a decrease in received data or received grants has occurred since the measurement gap, and the UE may transmit SR accordingly to prevent the serving base station from incorrectly determining the UE to be in the DRX off duration.

For example, if the UE has not received an uplink grant to transmit data after the measurement gap, the UE may trigger the regular BSR and initiate a SR procedure. For instance, the UE may periodically transmit SR on PUCCH a configured number of times until the UE receives an uplink grant from the serving base station (e.g. eNB <NUM> or gNB <NUM>), in response to which the UE may transmit the BSR (e.g. in a MAC-CE). As a result of the SR (or BSR), the serving base station may determine that the UE is not in a DRX mode or DRX off duration and that the UE is thus able to decode scheduling grants and data, thereby preventing data stalling and improving data throughput.

<FIG> illustrates an example <NUM> of a call flow between a UE <NUM> and base stations <NUM>, <NUM>, <NUM>. Referring to <FIG>, UE <NUM> may correspond to UE <NUM>, base station <NUM> may correspond to eNB <NUM> in serving cell A, base station <NUM> may correspond to gNB <NUM> in serving cell B, and base station <NUM> may correspond to neighbor base station <NUM> in neighbor cell C. Alternatively, in some cases, base station <NUM> may correspond to gNB <NUM> in serving cell B, and base station <NUM> may correspond to eNB <NUM> in serving cell A. The UE <NUM> may initially receive a measurement configuration <NUM> from base station <NUM> configuring the UE to perform measurements of a downlink signal <NUM> from base station <NUM>. The measurement configuration <NUM> may also include a measurement gap <NUM> indicating the period of time during which the UE is to perform the measurements (e.g. measurement gap <NUM>). Afterwards, the UE may receive data <NUM> and uplink grants <NUM> from base station <NUM>, as well as reference signals (e.g. CSI-RS) and scheduling grants for downlink data and CSI reports. Although not shown, the UE may similarly receive data <NUM> and uplink grants <NUM> from base station <NUM>.

Next, at <NUM>, the UE may determine that a threshold amount of data (e.g. data <NUM>) or a threshold amount of uplink grants (e.g. uplink grants <NUM>) is received from a serving base station within a threshold amount of time. For example, the UE <NUM> may determine that at least <NUM> KB of data (or some other number) or at least <NUM> uplink grants (or some other number) was received from base station <NUM> (or base station <NUM>) in the last <NUM> (or some other number) before measurement gap <NUM>. Then, at <NUM>, the UE may perform a measurement of a downlink signal from a neighbor base station based on the measurement configuration. For example, the UE <NUM> may measure an RSRP, a reference signal receive quality (RSRQ), or a signal-to-noise ratio (SNR) of downlink signal <NUM> (e.g. SSB, CSI-RS, DMRS, etc.) from base station <NUM> during measurement gap <NUM>, as configured in measurement configuration <NUM>. After performing the measurement, then at <NUM>, the UE may determine that another threshold amount of data or another threshold amount of uplink grants is not received from the serving base station within another threshold amount of time. For example, the UE <NUM> may determine that at least <NUM> KB of data (or some other number) or at least <NUM> uplink grants (or some other number) was not received from base station <NUM> (or base station <NUM>) in the last <NUM> (or some other number) after measurement gap <NUM>. For instance, as illustrated in <FIG>, the UE may determine that no data or uplink grants were received from base station <NUM> or <NUM> after performing the measurement at <NUM>.

Accordingly, at <NUM>, the UE may identify a decrease in amount of received downlink data or uplink grants from the serving base station based on the determinations at <NUM> and <NUM>, and consequently the UE may transmit a scheduling request <NUM> to base station <NUM> (or base station <NUM>) to inform the serving base station that the UE has data available to transmit. As a result, the base station <NUM> (or <NUM>) may send an uplink grant <NUM> to the UE <NUM> including configured resources for the uplink transmission, and the UE may subsequently send a BSR <NUM> to the corresponding base station in the configured resources. Thus, a degradation in data throughput may be avoided. Additionally, while the example of <FIG> illustrates the determination at <NUM> being performed before the measurement at <NUM>, in other examples, the UE may perform the determination at <NUM> after performing the measurement at <NUM>.

Moreover, while <FIG> illustrates the example where the UE transmits SR in response to identifying that a decrease has occurred in either an amount of received downlink data or an amount of uplink grants, the UE may alternatively transmit SR in response to identifying that a decrease has occurred in both an amount of received data and an amount of uplink grants. In such case, the UE may perform the determinations at <NUM> and <NUM> separately for each amount (i.e. data and uplink grants) based on same or different threshold amounts of data, uplink grants, or time. For instance, the UE may transmit SR in response to identifying that at least <NUM> KB of data (or some other number) was not received from base station <NUM> (or base station <NUM>) in the last <NUM> (or some other number) after measurement gap <NUM>, and in response to further identifying that at least <NUM> uplink grants were not received from base station <NUM> (or base station <NUM>) in the last <NUM> (or some other number) after measurement gap <NUM>. Thus, SR may be transmitted in response to decreases in received downlink data, decreases in received uplink grants, or a combination of the two.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a UE (e.g., the UE <NUM>, <NUM>, <NUM>, <NUM>; the apparatus <NUM>). Optional aspects are illustrated in dashed lines. The method allows a UE to trigger initiation of an SR procedure in response to a decrease in at least one of an amount of received downlink data or uplink grants following a measurement gap in order to avoid inefficient data stalls caused by erroneous DRX determinations by a base station.

At <NUM>, the UE receives data from a first base station. For example, <NUM> may be performed by data component <NUM>. For instance, referring to <FIG>, the UE <NUM> may receive data <NUM> from base station <NUM>. The UE <NUM>, <NUM> may receive the data <NUM> from base station <NUM>, <NUM>, for example, according to the following example process: the UE may obtain the data using one or more of the antennas <NUM>, the UE may demodulate the obtained data (e.g., in RX processor <NUM>), and the UE may decode the demodulated data (e.g., in the controller/processor <NUM>). The UE may also store the decoded data in memory <NUM>.

At <NUM>, the UE may determine, before performing a measurement of a downlink signal from a second base station, that a threshold amount of data is received from the first base station within a threshold length of time. Alternatively or additionally, the UE may determine at <NUM>, before performing the measurement, that a threshold number of uplink grants is received from the first base station within a threshold length of time. Thus, at <NUM>, the UE may determine, before performing the measurement, that at least one of a threshold amount of data or a threshold number of uplink grants is received from the first base station within a threshold length of time. For example, <NUM> may be performed by first determination component <NUM>. For instance, referring to <FIG>, the UE <NUM> may determine at <NUM>, before performing a measurement at <NUM> of downlink signal <NUM> from base station <NUM>, that a threshold amount of data such as x bytes of data and/or a threshold number of uplink grants such as z number of grants is received from base station <NUM> within a threshold length of time such as y ms before measurement gap <NUM>. The thresholds x and z may be the same as or different from each other. In an example process of making the determination at <NUM>, the UE <NUM> (e.g., the controller/processor <NUM> of UE <NUM>) may count, within a configured (threshold) period of time y ms (prior to measuring downlink signal <NUM>), a number of bytes of data received from base station <NUM> and/or a number of uplink grants received from base station <NUM>, the UE may compare the counted number of bytes and/or number of uplink grants with a threshold amount of data (x bytes) and/or a threshold number of uplink grants (z grants), respectively, and the UE may identify that the counted number of bytes and/or number of uplink grants at least meet the threshold amount of data and/or threshold number of uplink grants, respectively (e.g., the number of counted bytes is at least x bytes and/or the number of counted grants is at least z grants).

At <NUM>, the UE performs the measurement of the downlink signal from the second base station based on a measurement configuration. For example, <NUM> may be performed by measurement component <NUM>. For instance, referring to <FIG>, the UE <NUM> may perform the measurement at <NUM> of downlink signal <NUM> from base station <NUM>. In an example process of performing the measurement at <NUM>, the UE (e.g., the controller/processor <NUM> of UE <NUM>) may receive the downlink signal from base station <NUM> (e.g., using one or more antennas <NUM> and following demodulation and decoding of the downlink signal), and the UE may obtain an RSRP, a RSRQ, or a SNR of the downlink signal <NUM>. Moreover, the measurement may be performed at <NUM> based on the measurement configuration <NUM>. For instance, the measurement configuration may include one or more measurement objects indicating the frequency, time location, and subcarrier spacing of reference signal(s) (e.g., downlink signal <NUM>) the UE is to measure (e.g. SSB, CSI-RS, DMRS, etc.) from base station <NUM>, and the UE may perform the measurement of the reference signal(s) indicated in the configured measurement object(s). The measurement configuration may be received from a third base station in dual connectivity with the first base station (e.g. base station <NUM> such as illustrated in <FIG>). Alternatively, the measurement configuration may be received from the first base station (e.g. base station <NUM>) in another example. Furthermore, the measurement configuration may indicate a measurement gap (e.g. measurement gap <NUM>), and the measurement may be performed at <NUM> during the measurement gap. For instance, the UE may measure the reference signal(s) indicated in the configured measurement object(s) during the measurement gap <NUM> indicated in the measurement configuration.

At <NUM>, the UE may determine, after performing the measurement, that another threshold amount of data is not received from the first base station within another threshold length of time. Alternatively or additionally, the UE may determine at <NUM>, after performing the measurement, that another threshold number of uplink grants is not received from the first base station within another threshold length of time. Thus, at <NUM>, the UE may determine, after performing the measurement, that at least one of another threshold amount of data or another threshold number of uplink grants is not received from the first base station within another threshold length of time. For example, <NUM> may be performed by second determination component <NUM>. The another threshold amount of time may be the same as, or different from, the threshold amount of time referenced at <NUM>, the another threshold number of uplink grants may be the same as, or different from, the threshold number of uplink grants referenced at <NUM>, and the another threshold length of time may be the same as, or different from, the threshold length of time referenced at <NUM>. For instance, referring to <FIG>, the UE <NUM> may determine at <NUM>, after performing the measurement at <NUM>, that another threshold amount of data such as a bytes of data or another threshold number of uplink grants such as c number of uplink grants is not received from base station <NUM> within another threshold length of time such as b ms after measurement gap <NUM>. In an example process of making the determination at <NUM>, the UE <NUM> (e.g., the controller/processor <NUM> of UE <NUM>) may count, within a configured (threshold) period of time b ms (after measuring downlink signal <NUM>), a number of bytes of data received from base station <NUM> and/or a number of uplink grants received from base station <NUM>, the UE may compare the counted number of bytes and/or number of uplink grants with a threshold amount of data (a bytes) and/or a threshold number of uplink grants (c grants), respectively, and the UE may identify that the counted number of bytes and/or number of uplink grants do not meet the threshold amount of data and/or threshold number of uplink grants, respectively (e.g., the number of counted bytes is less than a bytes and/or the number of counted grants is less than c grants). The thresholds a and c may be the same as or different from each other, the thresholds a and x may be the same as or different from each other, the thresholds c and z may be the same as or different from each other, and the thresholds b and y may be the same as or different from each other.

At <NUM>, the UE may identify a decrease in an amount of received downlink data based on the determinations at <NUM> and <NUM>. Alternatively or additionally, the UE may identify at <NUM> a decrease in an amount of received grants to transmit uplink data based on the determinations at <NUM> and <NUM>. Thus, at <NUM>, the UE may identify a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data based on the determinations at <NUM> and <NUM>. For example, <NUM> may be performed by identification component <NUM>. For instance, referring to <FIG>, the UE <NUM> may identify at <NUM> a decrease in an amount of received downlink data since measurement gap <NUM> based on the determinations at <NUM> and <NUM>. Alternatively or additionally, the UE <NUM> may identify at <NUM> a decrease in an amount of received grants to transmit uplink data since measurement gap <NUM> based on the determinations at <NUM> and <NUM>. In an example process of making the identification at <NUM>, the UE (e.g., the controller/processor <NUM> of UE) may determine as described above at <NUM> that a counted number of received bytes and/or counted number of received uplink grants prior to the measurement gap at least meet the threshold amount of data and/or threshold number of uplink grants, the UE may determine as described above at <NUM> that another counted number of received bytes and/or another counted number of received uplink grants after the measurement gap do not meet the threshold amount of data and/or threshold number of uplink grants, and the UE may ascertain the decrease has occurred in response to both determinations.

At <NUM>, the UE transmits a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed at <NUM>. For example, <NUM> may be performed by scheduling request component <NUM>. The decrease may be the decrease identified at <NUM>. For instance, referring to <FIG>, the UE <NUM> may transmit scheduling request <NUM> to base station <NUM> in response to the identification of the decrease at <NUM> and after performing the measurement at <NUM>. The scheduling request may be transmitted in an absence of receiving a grant after performing the measurement at <NUM>. For instance, the UE <NUM> may transmit scheduling request <NUM> if the UE does not receive an uplink grant from base station <NUM> following measurement gap <NUM>. The UE <NUM>, <NUM> may transmit the scheduling request to base station <NUM>, <NUM>, for example, according to the following example process: the UE may encode the scheduling request (e.g., in the controller/processor <NUM>), the UE may modulate the encoded scheduling request (e.g., in the TX processor <NUM>), and the UE may send the modulated and encoded scheduling request using one or more of the antennas <NUM>.

The scheduling request may also be transmitted at <NUM> in response to a BSR being triggered. For instance, referring to <FIG>, the UE may trigger a BSR in response to identifying the decrease at <NUM> (and <NUM>), after which the UE transmits the scheduling request <NUM> at <NUM>. Moreover, after transmitting the scheduling request, at <NUM>, the UE may receive an uplink grant in response to the scheduling request, and at <NUM>, the UE may transmit the BSR in response to the uplink grant. For example, <NUM> may be performed by uplink grant component <NUM>, and <NUM> may be performed by BSR component <NUM>. For instance, referring to <FIG>, the UE <NUM> may receive uplink grant <NUM> in response to the scheduling request <NUM>, and the UE may transmit BSR <NUM> in response to uplink grant <NUM>. The UE <NUM>, <NUM> may receive the uplink grant from base station <NUM>, <NUM>, for example, according to the following example process: the UE may obtain the grant using one or more of the antennas <NUM>, the UE may demodulate the obtained grant (e.g., in RX processor <NUM>), and the UE may decode the demodulated grant (e.g., in the controller/processor <NUM>). The UE may also store the decoded grant in memory <NUM>. Moreover, the UE <NUM>, <NUM> may transmit the BSR to base station <NUM>, <NUM>, for example, according to the following example process: the UE may encode the BSR (e.g., in the controller/processor <NUM>), the UE may modulate the encoded BSR (e.g., in the TX processor <NUM>), and the UE may send the modulated and encoded BSR using one or more of the antennas <NUM>.

In one example, the second base station may be of a different RAT than the first base station. For instance, referring to <FIG>, base station <NUM> may an eNB while base station <NUM> may be a gNB. In another example, the downlink signal from the second base station may be received on a different frequency than the data received from the first base station. For instance, referring to <FIG>, downlink signal <NUM> from base station <NUM> may be received on different frequency than data <NUM> from base station <NUM>. In a further example, the second base station may be in a different cell than the first base station. For instance, referring to <FIG>, base station <NUM> may be in a different cell (e.g. neighbor base station <NUM> in cell C of <FIG>) than base station <NUM> (e.g. gNB <NUM> in cell B of <FIG>).

The communication manager <NUM> includes a data component <NUM> that is configured to receive data from a first base station, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes a first determination component <NUM> that receives input in the form of data from data component <NUM> and is configured to determine, before performing the measurement, that at least one of a threshold amount of data or a threshold number of uplink grants is received from the first base station within a threshold length of time, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes a measurement component <NUM> that is configured to perform a measurement of a downlink signal from a second base station based on a measurement configuration, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes a second determination component <NUM> that receives input in the form of data from data component <NUM> and is configured to determine, after performing the measurement, that at least one of another threshold amount of data or another threshold number of uplink grants is not received from the first base station within another threshold length of time, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes an identification component <NUM> that receives input in the form of the determinations from first determination component <NUM> and second determination component <NUM> and is configured to identify the decrease in the at least one of the amount of the received downlink data or the number of the received grants to transmit the uplink data based on the determinations, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes a scheduling request component <NUM> that receives input in the form of the data from data component <NUM> and measurement from measurement component <NUM>, as well as the identification from identification component <NUM>, and is configured to transmit a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes an uplink grant component <NUM> that is configured to receive an uplink grant in response to the scheduling request, e.g., as described in connection with <NUM>. The communication manager <NUM> further includes a BSR component <NUM> that receives input in the form of the uplink grant from uplink grant component <NUM> and is configured to transmit the BSR in response to the uplink grant, e.g., as described in connection with <NUM>.

In one configuration, the apparatus <NUM>, and in particular the cellular baseband processor <NUM>, includes means for receiving data from a first base station, means for performing a measurement of a downlink signal from a second base station based on a measurement configuration, and means for transmitting a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed.

In one configuration, the measurement configuration may be received from the first base station or a third base station in dual connectivity with the first base station.

In one configuration, the scheduling request may be transmitted in an absence of receiving a grant after performing the measurement.

In one configuration, the scheduling request may be transmitted in response to a BSR being triggered. In one configuration, the means for receiving may be further configured to receive an uplink grant in response to the scheduling request, and the means for transmitting may be further configured to transmit the BSR in response to the uplink grant.

In one configuration, the measurement configuration may indicate a measurement gap, and the measurement may be performed during the measurement gap.

In one configuration, the second base station may be of a different RAT than the first base station. In one configuration, the downlink signal from the second base station may be received on a different frequency than the data received from the first base station. In one configuration, the second base station may be in a different cell than the first base station.

In one configuration, the apparatus <NUM>, and in particular the cellular baseband processor <NUM>, may include means for determining, before performing the measurement, that at least one of a threshold amount of data or a threshold number of uplink grants is received from the first base station within a threshold length of time. The means for determining may be further configured to determine, after performing the measurement, that at least one of another threshold amount of data or another threshold number of uplink grants is not received from the first base station within another threshold length of time. The apparatus <NUM>, and in particular the cellular baseband processor <NUM>, may also include means for identifying the decrease in the at least one of the amount of the received downlink data or the number of the received grants to transmit the uplink data based on the determinations.

The aforementioned means may be one or more of the aforementioned components of the apparatus <NUM> configured to perform the functions recited by the aforementioned means. As described supra, the apparatus <NUM> may include the TX Processor <NUM>, the RX Processor <NUM>, and the controller/processor <NUM>.

Claim 1:
A method of wireless communication at a user equipment, UE, comprising:
receiving (<NUM>) data from a first base station;
performing (<NUM>) a measurement of a downlink signal from a second base station based on a measurement configuration; and
transmitting (<NUM>) a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed.