Patent Description:
Ultra-reliable and low latency communication (URLLC) is one of the main use cases of fifth generation (<NUM>) new radio (NR). URLLC has strict requirements on transmission reliability and latency, i.e., <NUM>% reliability within <NUM> one-way latency. NR Rel-<NUM> includes several new features and enhancements to support these requirements. Rel-<NUM> standardization works are focused on further enhancing URLLC system performance as well as ensuring reliable and efficient coexistence of URLLC and other NR use cases. One example scenario is when both enhanced mobile broadband (eMBB) and URLLC user equipment (UEs) co-exist in the same cell. Two main approaches exist to support multiplexing/prioritization.

In addition to operation in licensed bands, NR includes operation in unlicensed bands, i.e., NR-unlicensed (NR-U). Allowing unlicensed networks, i.e., networks that operate in unlicensed or shared spectrum, to effectively use the available spectrum is an attractive approach to increase system capacity. For convenience, unlicensed spectrum herein may refer to both unlicensed and shared spectrum.

Although unlicensed spectrum does not match the qualities of the licensed regime, solutions that allow an efficient use of it as a complement to licensed deployments have the potential to bring great value to network operators, and, ultimately, to the wireless industry as a whole. Some features in NR need to be adapted to comply with the special characteristics of the unlicensed band as well as different regulations. Further, a UE intended to use unlicensed spectrum may employ clear channel assessment (CCA) schemes to find out whether the channel is free over a certain period.

One such technique is listen-before-talk (LBT). There are different flavors of LBT depending on which channel access mode the device uses and which type of data it wants to transmit in the upcoming transmission opportunity, referred to as channel occupancy time (COT). Common for all flavors is that the sensing is done in a particular channel (corresponding to a defined carrier frequency) and over a predefined bandwidth. Further, two modes of access operations are defined - frame-based equipment (FBE) and load-based equipment (LBE). In FBE mode, the sensing period is simple, while the sensing scheme in LBE mode is more complex.

FBE includes semi-static channel occupancy. An example is illustrated in <FIG>.

<FIG> is a timing diagram illustrating an example FBE procedure depicting Third Generation Partnership Project (3GPP) semi-static channel occupancy [ETSI harmonized standard EN <NUM><NUM> Section <NUM>. In FBE mode as defined in 3GPP specifications and illustrated in <FIG>, the gNB assigns fixed frame periods (FFPs), senses the channel for <NUM> just before the FFP boundary, and if the channel is sensed to be free, it starts with a downlink transmission, and allocates resources among different UEs in the FFP. This procedure can be repeated with a certain periodicity.

In the FFP, downlink/uplink transmissions are only allowed within the COT, a subset of FFP resources, where the remaining idle period is reserved so that other nodes also have the chance to sense and use the channel. Thus in FBE operations, the channel is sensed at specific intervals just before the FFP boundary. The FFP can be set to values between <NUM> and <NUM> and can be changed after a minimum of <NUM>. The IDLE period is a regulatory requirement and is supposed to be at least TIDLE ≥ max(<NUM>*COT, <NUM>). In 3GPP TS <NUM> this has been simplified to be TIDLE ≥ max(<NUM>*FFP, <NUM>), i.e., the maximum channel occupancy time, MCOT, is defined as TMCOT = min(<NUM>*FFP, FFP-<NUM>). So for <NUM> FFP, the MCOT is <NUM>, while for <NUM> FFP the MCOT is <NUM> = <NUM>*FFP.

LBE includes dynamic channel occupancy. The default LBT mechanism for LBE operation, LBT category <NUM>, is similar to existing Wi-Fi operation, where a node can sense the channel at any time and start transmitting if the channel is free after a deferral and back off period. For specific cases, e.g., shared COT, other LBT categories allowing a very short sensing period are allowed.

There are different wideband operation modes. The nodes perform LBT on a certain bandwidth referred to as the LBT channel, which are up to <NUM> to comply with WiFi channels. The transmission bandwidth is therefore also limited by the LBT bandwidth. The channels can however be aggregated in wideband operation modes using either carrier aggregation, where LBT is performed separately on each carrier, or using one wideband carrier which is divided into several resource block sets, RB set (also referred to as LBT bandwidth or LBT subband), where LBT is performed on each RB-set.

There currently exist certain challenges. For example, for COT initiation in FBE mode, only gNB initiated COT is considered in 3GPP specifications, i.e., gNB transmits in the beginning of the COT, then UEs may transmit within the same COT (there may be multiple switching points between downlink and uplink within the same COT). This may cause some issues.

If a configured grant (CG) opportunity falls in the beginning of a COT, then a gNB-initiated COT procedure may collide with the CG opportunity in the time-domain. Using gNB-initiating COT as the only option may not be desirable for some latency-critical situations. For example, if an urgent URLLC request needs immediate allocation, and if there is an allocation opportunity that intersects with the IDLE period and/or the beginning of the COT, then the UE cannot use the (full) allocation because the UE has to wait for gNB-initiation procedure in the beginning of the next COT.

Thus, UE-initiated COT is a useful alternative, but supporting this feature imposes new challenges. One is physical uplink shared channel (PUSCH) segmentation. If a PUSCH is segmented over the time-period that spans over part of two FFPs, then its segmentation behavior may depend on type of initiation - gNB or UE based.

<CIT> discloses a method and apparatus for frame-based equipment operation of NR unlicensed.

A 3GPP submission by Huawei et al. (R1-<NUM>, "Coexistence and channel access for NR unlicensed band operations") discloses coexistence and channel access for NR unlicensed band operations.

As described above, certain challenges currently exist with channel occupancy time (COT)/fixed frame period (FFP) scheduling in unlicensed spectrum. Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. For example, some embodiments include flexible scheduling where COT behavior is not restricted to gNB-initiated COT. Some embodiments consider other initiation-types and combination of modes, e.g., LBE and FBE, for flexible scheduling for reliable and low latency applications. Aspects of the invention are set out in the independent claims.

According to claim <NUM>, a method is performed by a wireless device for operation with shared spectrum channel access, wherein a first plurality of FFPs are associated with the wireless device and a second plurality of FFPs are associated with a network node and wherein each FFP comprises an idle period with no transmission and a COT for potential transmission. The method comprises initiating a COT in one of the FFPs of the first plurality of FFPs and upon successful initiation of the COT, transmitting uplink data from the beginning of the COT.

In particular embodiments, the method further comprises receiving an indication that the wireless device may initiate a COT in one of the FFPs of the first plurality of FFPs.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain. Transmitting uplink data may comprise refraining from transmitting uplink data in an idle period of any of the FFPs of the second plurality of FFPs. Transmitting uplink data may comprise segmenting the uplink data into two or more segments and refraining from transmitting any of the two or more segments that overlap with an idle period of any of the FFPs of the second plurality of FFPs. Transmitting uplink data may comprise segmenting the uplink data into two or more segments and refraining from transmitting all of the two or more segments if any of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs. Transmitting uplink data may comprise segmenting the uplink data into two or more segments and refraining from transmitting any of the two or more segments after one of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs.

In particular embodiments, transmitting uplink data comprises segmenting the uplink data into two or more segments and one segment of the two or more segments includes an indication that the wireless device will transmit the next segment of the two or more segments using wireless device initiated COT in a next FFP of the first plurality of FFPs.

In particular embodiments, the method further comprises determining the wireless device does not have uplink data to transmit at the beginning of a COT and transmitting at the beginning of the COT an indication to a base station that the wireless device does not have uplink data to transmit.

In particular embodiments, the method further comprises signaling to another wireless device or network node whether the wireless device was successfully able to obtain a COT for wireless device initiated COT.

According to independent claim <NUM>, a wireless device comprises processing circuitry operable to perform any of the wireless device methods described above.

According to independent claim <NUM>, a method is performed by a network node for operation with shared spectrum channel access, wherein a first plurality of FFPs are associated with a wireless device and a second plurality of FFPs are associated with the network node and wherein each FFP comprises an idle period with no transmission and a channel occupancy time (COT) for potential transmission. The method comprises determining a wireless device initiated a COT in one of the FFPs of the second plurality of FFPs and receiving uplink data from the beginning of the COT.

In particular embodiments, the method further comprises transmitting an indication that the wireless device may initiate COT in one of the FFPs of the first plurality of FFPs.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and uplink data is not received in an idle period of any of the FFPs of the second plurality of FFPs. The uplink data may be segmented into two or more segments and segments that overlap with an idle period of any of the FFPs of the second plurality of FFPs are not received. The uplink data may be segmented into two or more segments and none of the two or more segments are received if any of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs. The uplink data may be segmented into two or more segments and the segments are not received after one of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs.

In particular embodiments, the uplink data is segmented into two or more segments and one segment of the two or more segments includes an indication that the wireless device will transmit the next segment of the two or more segments using wireless device initiated COT in a next FFP of the first plurality of FFPs.

In particular embodiments, the method further comprises receiving at the beginning of a COT an indication that a wireless device does not have uplink data to transmit.

According to independent claim <NUM>, a network node comprises processing circuitry operable to perform any of the network node methods described above.

Certain embodiments may provide one or more of the following technical advantages. For example, in some embodiments the flexible COT behavior facilitates reliable and low latency transmissions.

As described above, certain challenges currently exist with channel occupancy time (COT)/fixed frame period (FFP) scheduling in unlicensed spectrum. Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.

Particular embodiments are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter set forth in the appended claims.

Particular embodiments include FFP/COT scheduling with a plurality of behavior governed by COT initiation (e.g., gNB and/or UE), and operational mode (FBE, LBE).

In a first group of embodiments, for NR-U operation, a radio resource control (RRC) or downlink control information (DCI) based signaling is used to disable or enable UE-initiated COT behavior. This means if a UE transmission falls in the beginning of a COT, the user equipment (UE) can perform LBT and transmit its data or control signaling in the beginning of the COT if the UE-initiated COT feature is enabled. The enabling or disabling of UE-initiated COT feature can be done, e.g., according to any of the following.

For example, the signaling may be in a unicast, or multicast, or broadcast manner (e.g., group-common DCI may be used). The signaling may be on the basis of component carriers (CCs), e.g., UE-initiated COT feature is disabled on some CCs and enabled on some other CCs. The signaling may be on the basis of listen-before-talk (LBT) channels in which the sensing procedure is performed if the cell is divided into multiple LBT channels.

The UE-initiated COT transmission, e.g., can include any of the following. They may include uplink data transmission over physical uplink shared channel (PUSCH), uplink control information (UCI) over physical uplink control channel (PUCCH) or PUSCH, sounding reference signals (SRS), and/or any uplink transmission initiated by the UE (e.g., physical random access channel (PRACH)).

In some embodiments, the FFPs of the gNB and UE(s) are fully aligned (same duration, same boundary). An example is illustrated in <FIG>.

<FIG> is a timing diagram illustrating gNB-initiated and UE-initiated COT transmission, according to a particular embodiment. <FIG> illustrates the planned data transmissions by gNB and UE in the first row. For gNB-initiated COT (2nd row), the second part of the UE transmission is postponed to the next uplink transmission opportunity after gNB initiates the next COT. Also, because of the UE transmission delay, the second part of the gNB is postponed to the 3rd COT.

With UE initiated COT, the UE can transmit the second part of its transmission directly after the first FFP at the beginning of the next COT, so that all transmissions can be performed in that COT.

In some embodiments, the FFPs of the gNB and UE(s) are not aligned (different duration, different boundaries). An example is illustrated in <FIG>.

<FIG> is a timing diagram illustrating gNB-initiated and UE-initiated COT transmission where the FFPs are not aligned, according to a particular embodiment. <FIG> illustrates the planned data transmissions by gNB and UE in the first row. As shown in the second row, illustrating gNB initiated COT only, the second UE transmission burst intersects with the IDLE period of the gNB's FFP. Therefore, the UE has to wait until the next gNB initiated COT and its downlink transmissions before the UE can transmit its data, leading to some uplink transmission delay.

If the gNB does not have downlink data, the gNB may decide not to initiate its COT. For a UE that is allowed to initiate its own COT within the gNB's unused FFP, the UE can perform the second transmission burst even in the gNB's IDLE period, because the gNB did not use its FFP. The gNB can initiate a new COT. However, whenever the COTs overlap, the nodes need to respect the other node's IDLE period. As illustrated in <FIG>, the gNB needs to cancel or postpone its transmission during the UE's IDLE period.

In a second group of embodiments, for NR-U operation with UE-initiated COT disabled in the gNB's FFP, if a PUSCH transmission (dynamic or CG based) occurs over the resource that spans over the FFP boundary, then the following embodiments handle segmentation of the repetition.

In some embodiments, the repetitions that overlap fully or partially with invalid resources are not transmitted. In this case, the resources that fall in the idle period plus an additional margin (X, where X><NUM>) are considered invalid. The UE may resume the transmission in the subsequent COT if it detects a downlink transmission that initiates that COT and has assigned resources (dynamically scheduled or configured). An example is illustrated in <FIG>.

<FIG> is a timing diagram illustrating the segmented part of a transport block that occurs over the idle period and resources meant for gNB-initiation of the COT that is not transmitted, according to a particular embodiments. As illustrated in <FIG>, the transmission (PUSCH transport block) is segmented into three repetitions, Rep#<NUM>, Rep#<NUM> and Rep#<NUM>. Rep#<NUM> occurs over the COT of an FFP where the transmission of the non-segmented PUSCH transport block (TB) is supposed to begin. Rep#<NUM> occurs over the Idle period plus the resource meant for gNB-COT initiation in the next FFP, and Rep#<NUM> occurs in the COT of next FFP after gNB-initiation.

There are multiple options for UE transmission behavior when the transmission intersects with the FFP boundary. In some embodiments, only the intersecting repetition is not transmitted by the UE, i.e., Rep#<NUM> and Rep#<NUM> are transmitted but Rep#<NUM> is not transmitted because it occurs over invalid symbols or resources.

In some embodiments, the complete PUSCH TB is not transmitted (i.e., Rep#<NUM>, Rep#<NUM> and Rep#<NUM> are not transmitted).

In some embodiments, only repetitions that can be transmitted in the current COT are transmitted, while all other repetitions that would occur within or after invalid symbols/resources and/or in the subsequent FFP are not transmitted, i.e., Rep#<NUM> is transmitted, while Rep#<NUM> and Rep#<NUM> are not transmitted.

In a third group of embodiments, for NR-U operation with UE-initiated COT enabled in the FFP, if a PUSCH transmission (dynamic or CG based) occurs over the resource that spans over the FFP boundary, then the following embodiments handle the segmentation of the repetition. The repetitions that overlap fully or partially with invalid resources are not transmitted. In this case, the resources that fall in the idle period are considered invalid. The UE may resume the transmission in the subsequent COT if it is assigned resources (dynamically scheduled or configured) and able to successfully initiate a UE COT at the beginning of the FFP. An example is illustrated in <FIG>.

<FIG> is a timing diagram illustrating a segmented part of the repetition over the idle period that is not transmitted, according to a particular embodiment. As illustrated in <FIG>, the transmission of the PUSCH TB is segmented into three repetitions Rep#<NUM>, Rep#<NUM> and Rep#<NUM>. Rep#<NUM> occurs over the COT of an FFP where the non-segmented PUSCH TB is supposed to begin. Rep#<NUM> occurs over the Idle period, and Rep#<NUM> occurs in the COT of the next FFP where the transmission of Rep#<NUM> acts as an indication of UE initiating the COT. Rep#<NUM> and Rep#<NUM> are transmitted but Rep#<NUM> is not transmitted because it occurs over invalid symbols or resource.

In some embodiments, the indication of UE-initiated COT with Rep#<NUM> can be indicated in Rep#<NUM>.

In a fourth group of embodiments, unlike in <FIG> and <FIG>, the Rep#<NUM> is transmitted after invalid symbols/resource, as illustrated in <FIG>.

<FIG> is a timing diagram illustrating a segmented part of the repetition that is overlapping with the invalid symbols is transmitted after invalid resource, according to a particular embodiment. The invalid symbols may indicate Idle period, or Idle period plus downlink resource (e.g., meant for gNB-initiated signaling).

In a fifth group of embodiments, any of the second, third, and fourth groups of embodiments may further comprise segmenting the repetition around the slot-boundary when the slot-boundary occurs in the COT/FFP.

In a sixth group of embodiments, if a UE is scheduled with transmission in the beginning of an FFP and the UE does not have data to transmit, then the UE can inform or signal gNB about "no data" transmission. This signaling (in the form of UCI/sequence over PUCCH or PUSCH) serves purpose of grabbing the COT and also enables the gNB to act fast because there will be no data transmission from the UE and the gNB needs to transmit or allocate resource to other UEs, in case the gNB intends to keep the COT (especially if interferers are operating in the same spectrum in the vicinity).

In a seventh group of embodiments, if a UE configured with normal/larger PUSCH (can belong to dynamic or CG allocation), then additional smaller PUSCH or PUCCH can be configured which begins at the same time as normal PUSCH.

The purpose of the smaller PUSCH or PUCCH is if there is no data to transmit in normal PUSCH, then the UE can transmit specific data sequence or UCI in smaller PUSCH or UCI in PUCCH. The transmission of the data sequence or UCI is useful when the gNB does not initiate the COT and waits for UE initiating the COT. With this, gNB is able to conserve the resources in normal PUSCH in case there is no data to transmit and at the same time allows the UE to grab the COT by transmitting in a smaller PUSCH/PUCCH so that the gNB may continue transmissions in the same COT.

In an eighth group of embodiments, for some carriers or channels, the UE-initiated COT behavior can be enabled and for some carriers, the behavior can be disabled.

In a ninth group of embodiments, the gNB can do dynamic or CG based allocation with cross-FFP scheduling (e.g., see <FIG>) where one repetition is allocated in one FFP and another in the next FFP. If a repetition falls in the beginning of the COT, then the following options can occur. Some of the options are described with respect to <FIG>.

<FIG> is a timing diagram illustrating an example where a UE transmits its repetition X in gNB-initiated COT (as gNB transmits some DL signaling in the beginning of the COT) and in the next COT, the UE initiates the transmission by transmitting next Rep#X+<NUM>.

If UE-initiated COT is not allowed, then the UE does not transmit that repetition (i.e., Rep#X+<NUM> in <FIG>). The UE waits for gNB-COT initiation signaling and if it receives or decodes the signaling, then the UE transmits its Rep#X+<NUM>. The gNB-COT initiation signaling happens over the initial part of the repetition resource meant for Rep#X+<NUM>, therefore following options can occur.

In one option, Rep#X+<NUM> occurs over the remaining resource (originally meant for Rep#X+<NUM> before gNB COT initiation signaling) if repetition X+<NUM> still can be accommodated, or the segment of Rep#X+<NUM> occurs over remaining resource and Rep#X+<NUM> is divided in two segments, one segment overlaps with gNB COT initiation signaling, and thus, this segment is not transmitted; other segment occurs over the remaining resource.

If UE-initiated COT is allowed, then in such scenarios, the UE can transmit right away from the beginning of a COT if the LBT at the end of idle period is successful (gNB can assume this repetition transmission as an implicit indication for COT initiation). The UE may indicate during its uplink transmissions in the gNB initiated COT that it will initiate the next COT.

In a tenth group of embodiments, if a UE is scheduled or performs transmission at the end of a COT and if it is also granted transmission in the beginning of the next FFP while the UE does not have more data to transmit, then the UE can inform or signal the gNB about "no data" transmission in the UCI and thus allow gNB to initiate the next COT.

An eleventh group of embodiments includes UE initiated COT in FBE scenario. If the UE transmissions for the UE are scheduled (i.e., not pre-configured), the gNB can derive the remaining COT duration that can be used by the gNB without an explicit indication from the UE.

If the UE performs the transmissions based on preconfigured resources, even though the start of the UE's COT is known to the gNB, the duration of the uplink transmission is up to the UE (depends on the UE's buffer, and the available resources). The UE could either indicate the start time for the gNB, or its own transmission duration (gNB start time = UE start time plus transmission duration), or the remaining COT (gNB start time = end of COT minus remaining COT). The UE may indicate to the gNB one of the parameters through a UCI (over PUSCH or PUCCH on preconfigured uplink resources).

In a twelfth group of embodiments, the repetitions (or multi-segment transmissions) are allocated based on which node initiates the COT. For example,. all repetitions may be on gNB-initiated COT(s) or all repetitions may be on UE-initiated COT(s). Some repetitions can be allocated on gNB-initiated COT(s) and some on UE-initiated COT(s) (e.g., see <FIG>).

In some embodiments, a repetition transmission may fall in the beginning of a COT, and if the UE is not allowed to initiate the COT by default, then following solutions can be considered. IN some embodiments, the UE skips the transmission in the beginning of the COT. In some embodiments gNB sends downlink signaling, e.g., a DCI in the beginning of COT, and then UE can transmit in the remaining resource, and the UE can include UCI (in the PUSCH transmission) indicating updated information to decode the transmission. In some embodiments, the gNB can inform the UE beforehand and give permission to initiate in such COTs where the UE's transmission falls in the beginning of the COT, and for this, an appropriate downlink signaling (DCI/reference signaling) may be used.

If the UE cannot grab the channel, the following solutions can be considered on how the gNB finds out about the loss of COT initiation by the UE. In some embodiments, ff the UE is allowed to transmit a TB in the beginning of the COT, and if the gNB does not detect the TB (i.e., DMRS of the TB), then the gNB concludes that the UE did not grab the COT. In some embodiments, if the UE is allowed to transmit UCI in the beginning of the COT, and if the gNB does not detect the UCI, then the gNB concludes that the UE did not grab the COT. In some embodiments, if the UE has UCI resource allocated later in the same FFP, i.e., FFP#A (and in another FFP, i.e. FFP#B) and may transmit negative feedback in the UCI about COT initiation (LBT failure indication) (e.g., see <FIG>). Additionally, the UE may indicate its buffer status so that the gNB may provide the UE with an uplink grant in the COT of FFP#B. In other words, this UCI can act as a scheduling request (SR).

<FIG> is a timing diagram illustrating UCI indicating COT-initiation failure for another FFP, according to a particular embodiment.

In some embodiments, a transmission may fall over the idle period of FFP, then following solutions can be considered. In some embodiments, the UE skips the transmission if a part of the transmission intersects the idle period. In some embodiments, the UE can transmit the transmission in the resource only that is not part of an idle period in an FFP (i.e., on COT only), and for this the UE may include UCI in the PUSCH transmission (to indicate the updated control information as the transmission is squeezed to fewer resource dynamically). Further options can be considered as well.

In some embodiments, if the resource is in the beginning of the COT, either gNB or UE-initiated COT can be employed. If, e.g., a transmission falls over the end of a COT, idle period and beginning of COT in the next FFP, then transmission can be divided into two or more segments where these segments are only transmitted in the COTs, i.e., one or more segments in the COT prior to the idle period and one or more segments in the COT later to the idle period.

Each segmented transmission may be equipped with UCI to indicate the decoding information, the segment identity, etc..

A thirteenth group of embodiments includes a single UE configured with both modes - LBE and FBE which can happen with resource allocation for the same HARQ process, e.g., (a) with different component carriers (CCs), (b) with different repetitions, (c) with transmission modes - initial transmissions, retransmissions and reattempt. In some embodiments, in a cell, some UEs can be configured with just FBE mode and some UEs with just LBE mode.

In a fourteenth group of embodiments, the UE is configured with both LBE and FBE mode and the UE can dynamically change between FBE and LBE mode where LBE mode operates as a fallback LBT mode.

In FBE mode, when UE or gNB determines COT is not initiated, the UE/gNB can attempt to access the channel performing LBE based channel access procedures. In this case, for initial transmission, the UE/gNB has to perform an LBT procedures based on LBE corresponding to the intended transmission properties, using LBE channel access rules.

The UE can include the type of LBT or mode of LBT in its uplink UCI. The gNB upon detection of the UCI and determining that the UE has performed Cat <NUM> LBT, may switch to channel access operation based on LBE in the current FFP or the next one or some other FFPs.

The gNB can include LBE channel access commands for uplink transmissions in the downlink control information to a UE or a group of UEs that are used for scheduling or other purposes, such as group common control signaling.

In another example, the gNB can indicate by using a flag in DCI to the UE or a group of UEs to switch to LBE mode and maintain LBE mode until indicated otherwise. The gNB can switch back to the FBE mode of operation starting for example from an FFP and indicate to the UEs using a flag in the DCI to the UE or a group of UEs to switch to FBE mode.

The FFPs that channel access modes can be changed within can follow a pattern provided by configuration, or dynamically signaled.

In a fifteenth group of embodiments, in a UE-initiated COT, the gNB signals other UEs sharing the COT regarding COT success (i.e., others UEs sharing the COT can transmit as per regulation for unlicensed operation). The signaling can be based on DCI transmitted over PDCCH or PDSCH, or in the form of transmission of reference or synchronization signals broadcasted/multicasted/unicasted to indicate the COT success.

In some embodiments, in a UE-initiated COT, the UE that initiated the COT signals other UEs for the COT success over side-link channels. The signaling can be transmitted over sidelink control channel (SLCCH) or sidelink shared channel (SLSCH) or a reference signal to indicate the COT success.

In some embodiments, in a UE-initiated COT, the gNB signals only other UEs sharing the COT if there is COT grabbing failure (i.e., COT is busy or occupied, and could not be up for grabbing). This is beneficial in controlled environment scenarios, for example, where COT success is highly probable and the gNB transmits signaling/indication only in case COT success failure because this incurs less signaling transmission overhead. The signaling may be based on DCI over PDCCH or PDSCH, or in the form of transmission of a reference or synchronization signal broadcasted/multicasted/unicasted to indicate the COT success failure.

In a sixteenth group of embodiments, the gNB a-priory selects which type of signaling information to be used to indicate COT success or not. For example, in an uncontrolled environment, the gNB may prefer to send signaling related to positive COT success (i.e., LBT before the COT is successful and the COT is up for grabbing) because the success probability may be low and therefore may have low signaling overhead. In a controlled environment, the gNB may prefer to deliver signaling indicating negative COT success (i.e., COT is busy or occupied, and could not be up for grabbing).

In the above embodiments, the transmissions can be in uplink or downlink. For example, if a transmission is in uplink, then data transmission can occur over PUSCH. Further, the PUSCH may be equipped with UCI (included in PUSCH) to update its decoding information. Similarly, in downlink, the data transmission may happen over PDSCH. Further, the PUSCH may be equipped with DCI (included in PDSCH) to update its decoding information.

In the above embodiments, the transmissions may be a part of SPS/CG or dynamic-based allocations wherever possible. The above embodiments may be used in separation or combinations.

Although particular embodiments and examples are described with respect to NR-U, the embodiments and examples are applicable generally to any shared spectrum channel access operation (e.g., not limited to unlicensed operation, but also applies to shared spectrum operation generally).

<FIG> illustrates an example wireless network, according to certain embodiments.

These components work together to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network.

Interface <NUM> is used in the wired or wireless communication of signaling and/or data between network node <NUM>, network <NUM>, and/or WDs <NUM>.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air.

In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network.

Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE). a vehicle-mounted wireless terminal device, etc. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device.

As yet another specific example, in an Internet of Things (IoT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.).

In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

Radio front end circuitry <NUM> is connected to antenna <NUM> and processing circuitry <NUM> and is configured to condition signals communicated between antenna <NUM> and processing circuitry <NUM>.

The benefits provided by such functionality are not limited to processing circuitry <NUM> alone or to other components of WD <NUM>, but are enjoyed by WD <NUM>, and/or by end users and the wireless network generally.

In some embodiments, processing circuitry <NUM> and device readable medium <NUM> may be integrated.

User interface equipment <NUM> is configured to allow input of information into WD <NUM> and is connected to processing circuitry <NUM> to allow processing circuitry <NUM> to process the input information. Using one or more input and output interfaces, devices, and circuits, of user interface equipment <NUM>, WD <NUM> may communicate with end users and/or the wireless network and allow them to benefit from the functionality described herein.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in <FIG>. For simplicity, the wireless network of <FIG> only depicts network <NUM>, network nodes <NUM> and 160b, and WDs <NUM>, 110b, and 110c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node <NUM> and wireless device (WD) <NUM> are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices' access to and/or use of the services provided by, or via, the wireless network.

<FIG> illustrates an example user equipment, according to certain embodiments.

Certain UEs may use all the components shown in <FIG>, or only a subset of the components.

<FIG> is a flowchart illustrating an example method in wireless device, according to certain embodiments. In particular embodiments, one or more steps of <FIG> may be performed by wireless device <NUM> described with respect to <FIG>. The wireless device is operable to operate in shared spectrum channel access. A first plurality of FFPs are associated with the wireless device and a second plurality of FFPs are associated with a network node (e.g., network node <NUM>). Each FFP comprises an idle period with no transmission and a COT for potential transmission.

The method may begin at step <NUM>, where the wireless device (e.g., wireless device <NUM>) receives an indication that the wireless device may initiate a COT in one of the FFPs of the first plurality of FFPs. For example, wireless device <NUM> may receive the indication from network node <NUM> (e.g., via RRC, DCI, etc.). The indication may be unicast, multicast or broadcast. The indication may be per component carrier or per LBT channel. The indication may comprise any of the indications described with respect to the first group of embodiments above.

At step <NUM>, the wireless device initiates a COT in one of the FFPs of the first plurality of FFPs and at step <NUM> transmits uplink data from the beginning of the COT. For example, wireless device <NUM> may transmit uplink data over PUSCH, UCI over PUSCH or PUCCH, PRACH, reference signals, or any other transmission initiated by a wireless device. Examples are illustrated in <FIG>.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and transmitting uplink data comprises refraining from transmitting uplink data in an idle period of any of the FFPs of the second plurality of FFPs. For example, the wireless device does not transmit uplink in its own idle periods and the wireless device also refrains from transmitting in the idle period of the network node. An example is illustrated in <FIG>.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and transmitting uplink data comprises segmenting the uplink data into two or more segments and refraining from transmitting any of the two or more segments that overlap with an idle period of any of the FFPs of the second plurality of FFPs. An example is illustrated in <FIG>.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and transmitting uplink data comprises segmenting the uplink data into two or more segments and refraining from transmitting all of the two or more segments if any of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs. That is, if any of the segments overlap with an idle period of the network node, the wireless device does not transmit any of the segments.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and transmitting uplink data comprises segmenting the uplink data into two or more segments and refraining from transmitting any of the two or more segments after one of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs. That is, the wireless device transmits segments until one segment overlaps with an idle period of the network node and then the wireless device refrains from transmitting any more subsequent segments.

In some embodiments, the wireless device may initiate a COT, but the wireless device may not have data to send, so the wireless device may inform the network node so that the network node may begin using the COT. In this case the method continues to step <NUM> where the wireless device determines the wireless device does not have uplink data to transmit at the beginning of a COT and step <NUM> where the wireless device transmits at the beginning of the COT an indication to a base station that the wireless device does not have uplink data to transmit.

In some embodiments, the wireless device may attempt to initiate a COT, but fails to successfully initiate the COT (e.g., collision occurred). In this case the method continues to step <NUM> where the network node signals to another wireless device or network node whether the wireless device was successfully able to obtain a COT for wireless device initiated COT. Examples are described with respect to the fifteenth, sixteenth, an seventeenth group of embodiments.

Modifications, additions, or omissions may be made to method <NUM> of <FIG>. Additionally, one or more steps in the method of <FIG> may be performed in parallel or in any suitable order.

<FIG> is a flowchart illustrating an example method in a network node, according to certain embodiments. In particular embodiments, one or more steps of <FIG> may be performed by network node <NUM> described with respect to <FIG>. The network node is operable to operate in shared spectrum channel access. A first plurality of FFPs are associated with a wireless device (e.g., wireless device <NUM>) and a second plurality of FFPs are associated with the network node. Each FFP comprises an idle period with no transmission and a COT for potential transmission.

The method may begin at step <NUM>, where the network node (e.g., network node <NUM>) transmits an indication that the wireless device may initiate COT in one of the FFPs of the first plurality of FFPs. The indication may be the indication described with respect to step <NUM> of <FIG>.

At step <NUM> the network node determines a wireless device initiated a COT in one of the FFPs of the second plurality of FFPs and at step <NUM> the network node receives uplink data from the beginning of the COT. Examples are described with respect to <FIG>.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and uplink data is not received in an idle period of any of the FFPs of the second plurality of FFPs. An example is illustrated in <FIG>.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and the uplink data is segmented into two or more segments and segments that overlap with an idle period of any of the FFPs of the second plurality of FFPs are not received.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and the uplink data is segmented into two or more segments and none of the two or more segments are received if any of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs.

In particular embodiments, the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and the uplink data is segmented into two or more segments and the segments are not received after one of the two or more segments overlap with an idle period of any of the FFPs of the second plurality of FFPs.

At step <NUM>, the network node may receive at the beginning of a COT an indication that a wireless device does not have uplink data to transmit. The network node may then use the COT for its own purposes.

At step <NUM>, the wireless device may signal to another wireless device or network node whether the wireless device was successfully able to obtain a COT for wireless device initiated COT. Examples are described above with respect to the fifteenth group of embodiments.

<FIG> illustrates a schematic block diagram of two apparatuses in a wireless network (for example, the wireless network illustrated in <FIG>). The apparatuses may comprise a network node and a wireless device (e.g., wireless device <NUM> and network node <NUM> in <FIG>). Apparatuses <NUM> and <NUM> are operable to carry out the example methods described with reference to <FIG> and <FIG>, respectively. Apparatuses <NUM> and <NUM> may be operable to carry out other processes or methods disclosed herein. It is also to be understood that the methods of <FIG> and <FIG> are not necessarily carried out solely by apparatuses <NUM> and <NUM>. At least some operations of the method can be performed by one or more other entities.

Virtual apparatus <NUM> may comprise processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments.

In some implementations, the processing circuitry may be used to cause receiving module <NUM>, determining module <NUM>, transmitting module <NUM>, and any other suitable units of apparatus <NUM> to perform corresponding functions according one or more embodiments of the present disclosure.

As illustrated in <FIG>, apparatus <NUM> includes receiving module <NUM> configured to receive an indication of whether the apparatus may initiate a COT, according to any of the embodiments and examples described herein. Determining module <NUM> is configured to determine uplink data is available, whether a transmission will overlap with an idle period, and how to segment a transmission if needed, according to any of the embodiments and examples described herein. Transmitting module <NUM> transmits uplink data according to any of the embodiments and examples described herein.

As illustrated in <FIG>, apparatus <NUM> includes receiving module <NUM> configured to receive uplink data from a wireless device, according to any of the embodiments and examples described herein. Determining module <NUM> is configured to determine whether a wireless device initiated a COT, according to any of the embodiments and examples described herein. Transmitting module <NUM> is configured to transmit an indication to a wireless device about whether the wireless device may initiate a COT, according to any of the embodiments and examples described herein.

NFV may be used to consolidate many network equipment types onto industry standard high-volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

Host computer <NUM> may be under the ownership or control of a service provider or may be operated by the service provider or on behalf of the service provider.

<FIG> illustrates an example host computer communicating via a base station with a user equipment over a partially wireless connection, according to certain embodiments. Example implementations, in accordance with an embodiment of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to <FIG>.

Connection <NUM> may be direct, or it may pass through a core network (not shown in <FIG>) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system.

While OTT connection <NUM> is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., based on load balancing consideration or reconfiguration of the network).

Wireless connection <NUM> between UE <NUM> and base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE <NUM> using OTT connection <NUM>, in which wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the signaling overhead and reduce latency, which may provide faster internet access for users.

A measurement procedure may be provided for monitoring data rate, latency and other factors on which the one or more embodiments improve. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection <NUM> passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above or supplying values of other physical quantities from which software <NUM>, <NUM> may compute or estimate the monitored quantities.

Additionally, or alternatively, in step <NUM>, the UE provides user data.

Modifications, additions, or omissions may be made to the systems and apparatuses disclosed herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. Additionally, operations of the systems and apparatuses may be performed using any suitable logic comprising software, hardware, and/or other logic. As used in this document, "each" refers to each member of a set or each member of a subset of a set.

Modifications, additions, or omissions may be made to the methods disclosed herein without departing from the scope of the invention. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order.

The foregoing description sets forth numerous specific details. It is understood, however, that embodiments may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation.

Although this disclosure has been described in terms of certain embodiments, alterations and permutations of the embodiments will be apparent to those skilled in the art in the sense that other changes, substitutions, and alterations are possible without departing from the scope defined by the claims below.

Claim 1:
A method performed by a wireless device for operation with shared spectrum channel access, wherein a first plurality of fixed frame periods, FFPs, are associated with the wireless device and a second plurality of fixed frame periods, FFPs, are associated with a network node and wherein each FFP comprises an idle period with no transmission and a channel occupancy time, COT, in which the wireless device or the network node is permitted to transmit, the method comprising:
initiating (<NUM>) a COT in one of the FFPs of the first plurality of FFPs; and
upon successful initiation of the COT, transmitting (<NUM>), to the network node, uplink data from the beginning of the COT,
characterized in that,
the first plurality of FFPs and the second plurality of FFPs are not aligned in the time domain and transmitting uplink data comprises segmenting the uplink data into two or more segments and refraining from transmitting any of the two or more segments that overlap with an idle period of any of the FFPs of the second plurality of FFPs.