Patent Description:
Currently the fifth generation ("<NUM>") of cellular systems, also referred to as New Radio (NR), is being standardized within the Third-Generation Partnership Project (3GPP). NR is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases.

<FIG> illustrates an exemplary high-level view of the <NUM> network architecture, consisting of a Next Generation RAN (NG-RAN) <NUM> and a <NUM> Core (5GC) <NUM>. NG-RAN <NUM> can include a set of gNodeB's (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs <NUM>, <NUM> connected via interfaces <NUM>, <NUM>, respectively. In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface <NUM> between gNBs <NUM> and <NUM>. With respect the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof.

NG-RAN <NUM> is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The NG-RAN architecture, i.e., the NG-RAN logical nodes and interfaces between them, is defined as part of the RNL. For each NG-RAN interface (NG, Xn, F1) the related TNL protocol and the functionality are specified. The TNL provides services for user plane transport and signaling transport.

The NG RAN logical nodes shown in <FIG> include a central (or centralized) unit (CU or gNB-CU) and one or more distributed (or decentralized) units (DU or gNB-DU). For example, gNB <NUM> includes gNB-CU <NUM> and gNB-DUs <NUM> and <NUM>. CUs (e.g., gNB-CU <NUM>) are logical nodes that host higher-layer protocols and perform various gNB functions such as controlling the operation of DUs. Each DU is a logical node that hosts lower-layer protocols and can include, depending on the functional split, various subsets of the gNB functions. As such, each of the CUs and DUs can include various circuitry needed to perform their respective functions, including processing circuitry, transceiver circuitry (e.g., for communication), and power supply circuitry.

A gNB-CU connects to gNB-DUs over respective F1 logical interfaces, such as interfaces <NUM> and <NUM> shown in <FIG>. The gNB-CU and connected gNB-DUs are only visible to other gNBs and the 5GC as a gNB. In other words, the F1 interface is not visible beyond gNB-CU.

Sidelink (SL) is a type of device-to-device (D2D) communication whereby UEs can communicate with each other directly rather than indirectly via a 3GPP RAN. The first 3GPP standardization of SL was in LTE Rel-<NUM> targeting public safety use cases. Since then, various enhancements have been introduced to broaden the use cases that could benefit from D2D technology. For example, the D2D extensions in LTE Rel-<NUM> and Rel-<NUM> include supporting vehicle-to-everything (V2X) communication.

3GPP Rel-<NUM> specifies the NR SL interface. NR Rel-<NUM> SL targets advanced V2X services, which can be categorized into four use case groups: vehicles platooning, extended sensors, advanced driving, and remote driving. The advanced V2X services require a new SL in order to meet the stringent requirements in terms of latency and reliability. The NR SL is designed to provide higher system capacity and better coverage, and to allow for extension to support the future development of even more advanced V2X services and other related services.

National security and public safety (NSPS) services often need to operate without (or with partial) RAN coverage, such as during indoor firefighting, forest firefighting, earthquake rescue, sea rescue, etc. In these scenarios, network coverage extension is a crucial enabler for NSPS. 3GPP Rel-<NUM> includes a study item for coverage extension for SL-based communication, including UE-to-network relay for cellular coverage extension and UE-to-UE relay for SL coverage extension. Additionally, improving performance of power-limited UEs (e.g., pedestrian UEs, first responder UEs, etc.) and improving the performance using resource coordination are also important goals for the Rel-<NUM> work.

Broadcast, groupcast, and unicast transmissions are desirable for the services targeted by NR SL. In groupcast (or multicast), the intended receiver of a message consists of only a subset of the possible recipients in proximity to the transmitter, whereas a unicast message is intended for only one recipient in proximity to the transmitter. For example, in the platooning service there are certain messages that are only of interest of the members of the platoon, for which groupcast can be used. Unicast is a natural fit for use cases involving only a pair of vehicles. Furthermore, NR SL is designed such that it is operable both with and without network coverage and with varying degrees of interaction between the UEs (user equipment) and the RAN, including support for standalone, network-less operation.

Two types of resource allocation modes are supported for NR SL between UEs. In NR SL resource allocation mode <NUM>, all SL transmissions between UEs are scheduled by the network (e.g., a serving gNB) using a configured grant or a dynamic grant. The network (e.g., serving gNB) can provide a UE with a configured SL grant via radio resource control (RRC) configuration. Configured SL grants typically allocate resources having a periodic, semipersistent pattern. Two types of configured SL grants are available, i.e., types <NUM> and <NUM>. In type <NUM>, the network can activate/deactivate the RRC-configured grant using DCI signaling. In other cases, the network may select the resources used for transmission but may give the transmitting SL UE some freedom to select some of the transmission parameters, possibly with some restrictions.

In SL resource allocation mode <NUM>, the resource allocation is performed by UE itself, e.g., autonomously based on sensing the carrier/resource pool for availability. In particular, the UE determines SL resource pool(s) by decoding sidelink control information (SCI) received from other UEs and/or by energy sensing, and selects a set of idle/available resources to use for its SL transmission. In this mode, there may be no intervention by the network (e.g., out of coverage, unlicensed carriers without a network deployment, etc.) or very minimal intervention by the network (e.g., configuration of pools of resources, etc.).

To summarize, SL resource allocation mode <NUM> is based on reservation of future resources and sensing-based resource allocation. Reservation of future resources is done so that a sending UE also notifies the receiving UE(s) about its intention to transmit using certain time-frequency resources at a later point in time. For example, a UE transmitting at time T informs the receivers that it will transmit using the same frequency resources at time T+<NUM>. This is referred to as a "booking message".

Resource reservation allows a UE to predict the utilization of the radio resources in the future. For example, a UE can obtain information about potential future transmissions by listening to the current transmissions of another UE. This information can be used by the UE to avoid collisions when selecting its own resources. As a more specific example, a UE predicts the future utilization of the radio resources by reading received booking messages and then schedules its transmissions to avoid using the same resources. This is known as sensing-based resource selection.

In cellular communication, discontinuous reception (DRX) refers to mechanisms that allow a node (typically a UE) to turn off at least part of its receiver circuitry when no incoming data is expected, which helps reduce node energy consumption. Broadly speaking, a UE in DRX has an Active Time (also referred to as Active Time state or ACTIVE state) during which it is expected to receive and process incoming transmissions as appropriate. For example, the UE is expected to decode downlink (DL) control channels, process grants, etc. Typically, UEs that are not in Active Time turn off some of their components and enter a low-energy (i.e., sleep) mode.

Prior-art document titled: "Discussion on resource allocation for power saving", 3GPP DRAFT; R1-<NUM>, discusses some of the agreements made on resource allocation schemes for UE power saving.

Advantageous embodiments are subject to the dependent claims.

In V2X, UEs are typically mounted in a vehicle and have no significant power restrictions. In contrast, NSPS use cases mostly involve handheld UEs for which energy efficiency is a concern. Accordingly, the Rel-<NUM> Work Item on NR SL includes the study and specification of SL DRX mechanism as one of its objectives.

However, since a UE can only sense resources when its receiver is active, SL DRX can cause various problems, issues, and/or difficulties for the sensing procedures used by UEs in SL resource selection, e.g., in SL mode <NUM> (autonomous). For example, there can be insufficient time for resource sensing due to SL DRX Active Time restrictions.

Embodiments of the present disclosure provide specific improvements to SL operation of UEs, such as by providing, enabling, and/or facilitating solutions to overcome exemplary problems summarized above and described in more detail below.

Embodiments include methods (e.g., procedures) for a UE configured for SL communication with one or more other UEs in a wireless network.

These exemplary methods include, while operating in SL discontinuous reception (SL-DRX) comprising a plurality of active times during which the UE's SL receiver is active and a plurality of inactive times during which the UE's SL receiver is inactive, receiving, at a time n, a trigger to select resources for a SL transmission. These exemplary methods also include extending a contiguous partial sensing, CPS, window after the trigger at time n when a portion of an active time is less than a first duration. The portion of the active time corresponds to an overlap of the active time with a remaining PDB associated with the SL transmission, while the first duration comprises a minimum contiguous partial sensing window (CPSWmin) followed by a minimum resource selection window (RSWmin).

These exemplary methods can also include performing at least one of the following during the portion of the active time: contiguous partial sensing (CPS) of resources, and selection of resources for the SL transmission.

In some embodiments, extending the CPS window can include, when the portion of the active time is less than the first duration, extending the CPS window to outside the active time, into an inactive time, such that the portion of the active time is extended to at least the first duration. During the extended portion of the active time, CPS is performed for at least CPSWmin and selection of resources is performed after CPS for at least RSWmin.

In some embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration of at least CPSWmin starting at the beginning of the portion of the active time while selection of resources is performed after CPS, for a duration of RSWmin until the end of the portion of the active time. In some of these embodiments, CPS is performed until the beginning of the selection of resources.

In other embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration of CPSWmin starting at the beginning of the portion of the active time, while selection of resources is performed after CPS for a duration of at least RSWmin, until the end of the portion of the active time.

In other embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration greater than CPSWmin, starting at the beginning of the portion of the active time. Also, selection of resources is performed after CPS for a duration greater than RSWmin, until the end of the portion of the active time.

In various embodiments summarized above, the selection of resources is based on the CPS (e.g., results or outcome).

In some embodiments, extending the CPS window when the portion of the active time is less than the first duration can include refraining from extending the CPS window when the trigger is received during an inactive time and a second duration between the time n and the beginning of the active time is less than CPSWmin. During the portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly from a pool of SL resources.

In other embodiments, extending the CPS window when the portion of the active time is less than the first duration can include refraining from extending the CPS window when a second duration between the time n and the end of the remaining PDB is less than CPSWmin plus RSWmin. During the portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly from a pool of SL resources.

In variants of these embodiments, the random selection of resources for the SL transmission is further based on the UE's channel occupancy ratio (CR) not exceeding a threshold.

In some embodiments, extending the CPS window when the portion of the active time is less than the first duration can include refraining from extending the CPS window when the portion of the active time is less than RSWmin. During the portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly from a pool of SL resources. In some of these embodiments, the selection of resources is performed randomly regardless of whether the CPS window can be extended such that CPS can be performed for at least CPSWmin.

In some embodiments, CPSWmin is based on one or more of the following: a packet priority level associated with the SL transmission, and a channel busy ratio (CBR) requirement. In some embodiments, RSWmin is based on one or more of the following: a packet priority level associated with the SL transmission, and a CBR requirement.

Other embodiments include UEs (e.g., wireless devices) that are configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing computer-executable instructions that, when executed by processing circuitry, configure such UEs to perform operations corresponding to any of the exemplary methods described herein.

These and other embodiments described herein can balance energy savings of SL-DRX with the need for reliable sensing to facilitate SL resource selection. Embodiments can improve reliability of the SL transmission due to the extended sensing operation in case the UE is in DRX, reduce energy consumption compared to a full-sensing operation, and trigger extended sensing operation as needed. Embodiments also provide a common UE behavior regarding the minimum contiguous sensing window which must be met irrespective of SL-DRX configuration or UE implementation, thereby improving overall system performance by reducing collisions caused by inadequate sensing.

These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

The steps of any methods and/or procedures disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein can be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments can apply to any other embodiments, and vice versa. Other objects, features, and advantages of the enclosed embodiments will be apparent from the following description.

Furthermore, the following terms are used throughout the description given below:.

The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and/or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and/or descriptions conflict with the above definitions, the above definitions should control.

Furthermore, although the term "cell" is used herein, it should be understood that (particularly with respect to <NUM> NR) beams may be used instead of cells and, as such, concepts described herein apply equally to both cells and beams.

<FIG> shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE (<NUM>), a gNB (<NUM>), and an access and mobility management function (AMF, <NUM>) in the 5GC. The Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. The PDCP layer provides ciphering/deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP. In addition, PDCP provides header compression and retransmission for UP data.

On the UP side, Internet protocol (IP) packets arrive to the PDCP layer as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection/correction, concatenation, segmentation/reassembly, sequence numbering, reordering of data transferred to/from the upper layers. The MAC layer provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (on gNB side). The PHY layer provides transport channel services to the MAC layer and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

On CP side, the non-access stratum (NAS) layer is between UE and AMF and handles UE/gNB authentication, mobility management, and security control. The RRC layer sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual-connectivity (DC) configurations for UEs. RRC also performs various security functions such as key management.

After a UE is powered ON it will be in the RRC_IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC_CONNECTED state (e.g., where data transfer can occur). The UE returns to RRC_IDLE after the connection with the network is released. In RRC_IDLE state, the UE's radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active times, an RRC_IDLE UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC_IDLE state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC_INACTIVE has some properties similar to a "suspended" condition used in LTE.

DRX functionality is also used by RRC_CONNECTED UEs. This allows a UE to turn off at least some of its receiver circuitry when no incoming data is expected, which helps reduce the energy consumption. When configured, the DRX functionality controls the expected UE behavior in terms of reception and processing of transmissions. Similar to RRC_IDLE DRX, RRC_CONNECTED DRX includes an Active Time (also referred to as Active Time state or ACTIVE state), in which the UE is expected to receive and process incoming transmissions as appropriate. For example, the UE is expected to decode the downlink (DL) control channels, process grants, etc. When the UE is not in Active Time (i.e., the UE is in Inactive Time), there is no expectation on the UE receiving and processing transmissions. That is, the base station cannot assume that the UE will be listening to DL transmissions. The DRX configuration defines the transitions between states. Note that a UE's RRC state is independent of its DRX state, such that a UE stays in its current RRC state when changing between DRX Active Time and Inactive Time.

Typically, UEs that are not in Active Time turn off some of their components and enter a reduced-energy (i.e., sleeping) mode. To ensure that the UE switches regularly to Active Time (i.e., wakes up), a DRX cycle is defined. This DRX cycle is controlled by two parameters: a periodicity, which controls how frequently the UE switches to Active Time; and a duration, which controls for how long the UE remains in active state each time it enters active state.

In addition to this basic cycle, the DRX procedures also define other conditions that may allow the UE to switch between Active Time and Inactive Time. For example, if a UE is expecting a retransmission from the gNB, the UE may enter Inactive Time (i.e., while the gNB prepares the retransmission) and then may enter Active Time (i.e., during a window in which the gNB may send the transmission).

A vehicle-to-everything (V2X) UE can support unicast communication via the uplink/downlink radio interface (also referred to as "Uu") to a 3GPP RAN, such as the LTE Evolved-UTRAN (E-UTRAN) or the NG-RAN. A V2X UE can also support SL unicast over the PC5 interface. <FIG> shows an exemplary arrangement of interfaces between two V2X UEs and a RAN. In addition to Uu and PC5 interfaces, the V2X UEs can communicate with a ProSe (PROximity-based SErvices) function via respective PC3 interfaces. Communication with the ProSe function requires a UE to establish a connection with the RAN, either directly via the Uu interface or indirectly via PC5 and another UE's Uu interface. The ProSe function provides the UE various information for network related actions, such as service authorization and provisioning of PLMN-specific information (e.g., security parameters, group IDs, group IP addresses, out-of-coverage radio resources, etc.). <FIG> also shows a PC4 interface between the ProSe function and the core network (CN).

<FIG> shows three exemplary network coverage scenarios for two UEs (<NUM>, <NUM>) and a gNB (<NUM>) serving a cell. In the full coverage scenario (left), both UEs are in the coverage of the cell, such that they both can communicate with the gNB via respective Uu interfaces and directly with each other via the PC5 interface. In the partial coverage scenario (center), only one of the UEs is in coverage of the cell, but the out-of-coverage UE can still communicate with the gNB indirectly via the PC5 interface with the in-coverage UE. In the out-of-coverage scenario, both UEs can only communicate with each other via the PC5 interface.

In general, the term "SL standalone" refers to direct communication between two SL-capable UEs (e.g., via PC5) in which source and destination are the UEs themselves. In contrast, the term "SL relay" refers to indirect communication between a network node and a remote UE via a first interface (e.g., Uu) between the network node an intermediate (or relay) UE and a second interface (e.g., PC5) between the relay UE and the remote UE. In this case the relay UE is neither the source nor the destination.

In general, an "out-of-coverage UE" is one that cannot establish a direct connection to the network and must communicate via either SL standalone or SL relay. A "peer UE" refers to a UE that can communicate with the out-of-coverage UE via SL standalone or SL relay (in which case the peer UE is also a relay UE).

UEs that are in coverage can be configured (e.g., by a gNB) via RRC signaling and/or system information. Out-of-coverage UEs rely on a (pre-)configuration available in their SIMs. These pre-configurations are generally static but can be updated by the network when a UE is in coverage.

As briefly mentioned above, in SL resource allocation mode <NUM>, the resource allocation is performed by UE itself, e.g., autonomously based on sensing the carrier/resource pool for availability. In particular, this mode uses distributed resource selection in which there is no central scheduling node. Mode <NUM> is based on two functionalities: reservation of future resources and sensing-based resource allocation. Reservation of future resources is done so that a sending UE also notifies the receiving UE(s) about its intention to transmit using certain time-frequency resources at a later point in time. For example, a UE transmitting at time T informs the receivers that it will transmit using the same frequency resources at time T+<NUM>. This is referred to as a "booking message".

The sensing-based resource selection technique for NR Rel-<NUM> SL is specified in 3GPP TS <NUM> (v16. <NUM>) and can be summarized in the following operations:.

Although sensing plays a key role in the SL resource selection, sensing also consumes significant energy. Thus, a Rel-<NUM> enhancement for power-limited SL devices is partial sensing, which aims to reduce sensing time used by a UE while maintaining a decent level of performance. So far, 3GPP has agreed to support two types of partial sensing: periodic-based partial sensing (PBPS), which is a similar procedure as the one used in LTE; and continuous partial sensing (CPS), which is a new procedure in NR. Another alternative is random resource selection, where the UE selects resources randomly without sensing.

<FIG> shows an example of PBPS. In this example, the UE performs sensing during a subset of resources based on a set of periodicities, which are defined in the parameter sl-ResourceReservePeriodList. As shown in <FIG>, the UE performs sensing during a subset of resources every P ms. Using this procedure, the UE reduces energy consumption relative to continuous sensing, but at the expense of an increase in the likelihood of collision because the UE is unable to collect complete channel occupancy information due to reduced sensing time.

<FIG> shows an example of CPS. In this example, the UE performs sensing after an event at time n that triggers a transmission. Since the UE is in partial sensing operation, there is no sensing prior to time n, thereby reducing energy consumption. The sensing procedure consumes part of the PDB of the packet, however, which reduces the potential size of the resource selection window.

<FIG> shows the case where a UE performs contiguous partial sensing during a window size defined by [n+TA, n+TB] and the remaining part of the PDB (i.e., S) is allocated for the resource selection window. This behavior for the contiguous sensing window is aligned with some agreements made in 3GPP. In particular, when the UE performs only CPS in a mode <NUM> Tx pool with periodic reservation for another TB (sl-MultiReserveResource) disabled, and a resource (re)selection is triggered in slot n:.

As briefly mentioned above, the Rel-<NUM> Work Item on NR SL includes the study and specification of SL DRX mechanism as one of its objectives. This includes defining SL DRX configurations and the corresponding UE procedure, specifying mechanisms to align sidelink DRX configurations among the UEs communicating with each other, and specifying mechanisms to align sidelink DRX configurations with Uu DRX configurations for an in-coverage UE.

3GPP RAN Working Group <NUM> has reached a number of agreements on the design of SL DRX. In general, similar to Uu DRX, SL DRX includes a set of timers that define the Active Time and a set of timers that define the Inactive Time. For example, the sl-drx-OnDuration timer defines the Active duration in each DRX cycle. Details of each timer and the related procedures for each casting type (i.e., unicast, groupcast, broadcast) are under discussion. Another feature of SL DRX under development in Rel-<NUM> is a mechanism to align the Active Times of a transmitter UE and the intended receiver UEs. This will help maximize the energy savings of SL DRX.

SL DRX impacts the resource selection sensing procedure in SL mode <NUM> because a UE can only sense the resources during SL-DRX Active Time according to its SL-DRX configuration. However, it is under discussion in 3GPP whether the sensing operation is allowed during the SL-DRX Inactive Time, i.e., whether the UE can turn on its receiver outside its SL-DRX Active Time to perform sensing and if so, under what condition such operation is allowed.

Typically, when a packet arrives at the MAC and PHY layers of the UE, the packet will trigger a resource selection. Each packet typically has a particular packet delay budget (PDB) that the resource selection protocol at the UE tries to fulfill. In other words, the UE will attempt to find resources to transmit the packet within the remaining PDB, after which the packet might be considered obsolete. As a result, when SL-DRX is configured, if the UE is only allowed to perform sensing during SL-DRX Active time, the UE may have little or no time for sensing before it must transmit the packet to fulfill the PDB.

<FIG> illustrates an exemplary scenario involving CPS for a SL transmission associated with a PDB. In this example, n denotes the time of resource selection trigger. Due to the large gap between n and the start of the SL DRX Active Time of the UE, the portion of the Active Time that can be used for sensing is too small for the sensing result to be meaningful. Moreover, the UE often needs to retain a time window, after the sensing, from which the resources are selected (denoted resource selection window, RSW, in <FIG>).

Accordingly, embodiments of the present disclosure address these and other problems, issues, and/or difficulties by providing techniques for contiguous partial sensing to achieve a minimum sensing duration (e.g., minimum CPS window) regardless of SL DRX Active or Inactive Time associated with at UE's SL DRX configuration and when the PDB allows for it. For example, in case the overlap between a configured CPS window and a DRX Active time is less than a minimum CPS window requirement, the UE starts sensing outside the DRX active time to meet the minimum CPS window requirement.

Embodiments can provide various benefits and/or advantages. For example, embodiments can balance energy savings of SL-DRX with the need for reliable sensing to facilitate SL resource selection. More specifically, embodiments can improve the reliability of the SL transmission due to the extended sensing operation in case the UE is in DRX mode, reduce energy consumption compared to a full-sensing operation, and trigger extended sensing operation as needed. Also, embodiments provide a common UE behavior regarding the minimum contiguous sensing window. For instance, irrespective of SL-DRX configuration or UE implementation, the minimum contiguous sensing window is fulfilled improving the overall system performance, such as by reducing collisions caused by inadequate sensing.

In general, embodiments are described in the context of 3GPP SL communications directly between UEs rather than through an intermediate base station. Even so, underlying principles of the described embodiments are applicable to any kind of device-to-device (D2D) communications that involve sensing operations and DRX.

At a high level, embodiments provide a mechanism that enables a UE to perform sensing for a minimum contiguous sensing window size (CPSWmin), regardless of whether the UE is DRX Inactive Time or Active Time when the sensing should occur. In case the CPSWmin cannot be guaranteed within the Active Time, the UE is allowed to extend its sensing window outside of the (pre-)configured SL-DRX Active Time.

In various embodiments, the value of CPSWmin can be defined in specifications or (pre-)configured based on certain parameters, e.g., based on channel busy ratio (CBR) level or on the priority of the SL transmission. For example, a larger value of CPSWmin can be associated with a higher priority level of the packet and/or with a higher CBR. Likewise, a lower priority level or lower CBR can be associated with a lower value of CPSWmin.

Additionally, a minimum size of the resource selection window (RSW) can be defined, denoted RSWmin. For example, RSWmin can also be defined in the specifications or (pre-) configured based on packet priority and/or CBR.

Depending on the relation of the PDB, CPSWmin, RSWmin, and SL DRX Active Time of a UE, different rules for UE continuous partial sensing are applied, as discussed in more detail below. The rules can be configured by the network, or (pre)configured to the UE, or defined by a standard specification.

In some embodiments, RSWmin is prioritized to be fulfilled within the SL DRX Active Time. Various rules can be applied in these embodiments, as described below.

In case CPSWmin cannot be fulfilled during SL-DRX Active Time, the CPS window is extended to SL-DRX Inactive time, up to a value that fulfills at least the CPSWmin. More specifically, when the Active Time before PDB expiration is smaller than CPSWmin + RSWmin (potentially with some additional time for UE processing delay), the UE prioritizes operation to ensure that the RSWmin is fulfilled and extends the sensing time to outside the Active Time so that the CPSWmin is fulfilled. The extended sensing time is noted as Extended Contiguous Partial Sensing Window (ECPSW). The duration of ECPSW can at UE's discretion, so long as CPSWmin is fulfilled. <FIG> shows an example scenario according to these embodiments.

In case CPSWmin can be fulfilled during the SL-DRX Active time, the UE can perform sensing in several ways. In some embodiments, when the Active Time before PDB expiration is larger than CPSWmin + RSWmin (potentially with some additional time for UE processing delays), the UE prioritizes fulfillment of RSWmin and starts sensing when Active Time starts. <FIG> shows an example scenario according to these embodiments.

In other embodiments, when the Active Time before PDB expiration is larger than CPSWmin + RSWmin (potentially with some additional time for UE processing delay), the UE prioritizes to ensure that the CPSWmin is fulfilled and uses the remaining Active Time for the resource selection window. <FIG> shows an example scenario according to these embodiments.

In other embodiments, when the Active Time before PDB expiration is larger than CPSWmin + RSWmin (potentially with some additional time for UE processing delays), the UE prioritize use the Active Time in such a way that the actual CPSW and RSW are larger than the corresponding minimum values. <FIG> shows an example scenario according to these embodiments.

In some cases, RSWmin can be fulfilled during the Active Time but PDB < RSWmin + CPSWmin. <FIG> shows an example scenario where RSWmin can be fulfilled within the Active Time, but CPSWmin cannot be fulfilled even with extended sensing outside Active Time. In these scenarios, the UE can perform resource selection in various ways. In some embodiments, the UE can perform random resource selection (e.g., without sensing) without additional condition. In other embodiments, the UE performs random resource selection with additional conditions, such as that the UE's channel occupancy ratio (CR) does not exceed a threshold and/or requirement.

<FIG> shows an example scenario where RSWmin cannot be fulfilled within the Active Time. When the UE encounters this condition, the UE can perform random resource selection (i.e., without sensing) for its SL transmission. Note that in this case the random resource selection is performed regardless of whether the CPSWmin can be fulfilled by extending sensing to outside the Active Time. One motivation for this rule is that RSWmin needs to consider the DRX Active Time of the intended recipient of the UE's transmission. The recipient's DRX active time can be assumed to be generally aligned with the transmitter UE's DRX Active Time based on DRX Active Time alignment mechanisms discussed above. Consequently, it is not possible for the UE to select any resource outside the Active Time for transmission to the recipient UE.

<FIG> shows a flowchart of an exemplary procedure that embodies the various rules and/or conditions discussed above. Although the operations in <FIG> are given numerical labels, this is done to facilitate the following explanation rather than to imply or require a particular order of the operations, unless expressly stated otherwise.

Based on a transmission triggered at time n (block <NUM>) and the values of CPSWmin and RSWmin being defined and/or pre-configured (block <NUM>), the UE starts the procedure. In block <NUM>, the UE checks whether the remaining PDB for the transmission is large enough to accommodate both CPSWmin and RSWmin. In case of not being able to accommodate both, in block <NUM> the UE checks whether at least RSWmin can be fulfilled. If that is not possible, then the UE performs a random resource selection (block <NUM>) without considering whether the sensing window can be fulfilled.

On the other hand, if at least RSWmin can be fulfilled, then in blocks <NUM>-<NUM> the UE selects a RSW that fulfills RSWmin and determines whether at least the CPSWmin can be fulfilled in the remaining PDB. If not, the UE proceeds to block <NUM> (discussed above) but if so, the UE proceeds to blocks <NUM> where it selects a CPSW that fulfills CPSWmin. In block <NUM>, the UE determines whether the selected CPSW is available during SL-DRX Active Time. If so, the UE proceeds to block <NUM> where it sets the selected CPSW ≥ CPSWmin during the SL-DRX Active Time. If not, then in block <NUM> the UE sets the selected CPSW ≥ CPSWmin which in this case means that the CPSW is extended to outside the SL-DRX Active Time, i.e., extended into SL-DRX Inactive Time, e.g., as illustrated in other figures. Thus, if CPSWmin cannot be fulfilled during the SL-DRX Active Time, then the sensing window, i.e. CPSW, is extended to the instants where the UE is in SL-DRX Inactive Time until fulfilling the CPSWmin value (block <NUM>).

In case the UE determines in block <NUM> that both CPSWmin and RSWmin can be fulfilled under the remaining PDB, the UE first selects a RSW ≥ RSWmin (block <NUM>) and determines whether the selected RSW is available during SL-DRX Active Time (block <NUM>). If so, the UE proceeds to blocks <NUM>-<NUM> (discussed above). On the other hand, if the selected RSW ≥ RSWmin is not available in SL-DRX Active Time, the UE determines whether CPSWmin can be fulfilled in the remaining PDB. If so, the UE proceeds to block <NUM> discussed above. If not, the UE proceeds to block <NUM> discussed above.

Various features of the embodiments described above correspond to various operations illustrated in <FIG>, which shows an exemplary method (e.g., procedure) for a user equipment (UE) configured for sidelink (SL) communication with one or more other UEs in a wireless network. In other words, various features of the operations described below correspond to various embodiments described above.

The exemplary method shown in <FIG> can be performed by a UE (e.g., wireless device, etc.) such as described elsewhere herein. Furthermore, the exemplary method can be used cooperatively to provide various benefits, advantages, and/or solutions to problems described herein. Although <FIG> shows specific blocks in a particular order, the operations of the exemplary method can be performed in a different order than shown and can be combined and/or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

The exemplary method can include the operations of block <NUM>, where while operating in SL discontinuous reception (SL-DRX) comprising a plurality of active times, e.g. SL-DRX active times, during which the UE's SL receiver is active and a plurality of inactive times, e.g. SL-DRX inactive times, during which the UE's SL receiver is inactive, the UE can receive a trigger to select resources for a SL transmission. The UE can receive the trigger at a triggering instant n, also denoted a time n or slot n. For example, the UE can receive the trigger during an inactive time (such as shown in <FIG>) or during an active time.

The exemplary method can also include the operations of block <NUM>, where the UE can extend, or selectively extend, a contiguous partial sensing, CPS, window after the trigger at time n when a portion of an active time, e.g. an SL-DRX active time, is less than a first duration. For example, the CPS window may be extended to outside the active time. The portion of the active time corresponds to an overlap of the active time with a remaining PDB associated with the SL transmission, while the first duration comprises a minimum contiguous partial sensing window (CPSWmin) followed by a minimum resource selection window (RSWmin).

The extending of the CPS window when the portion of the active time is less than the first duration in block <NUM> may thus be selectively performed e.g. in that there may be situations where the UE can refrain from extending the CPS window. Some examples are given below.

The exemplary method can also include the operations of block <NUM>, where the UE can perform at least one of the following during the portion of the active time: contiguous partial sensing (CPS) of resources, and selection of resources for the SL transmission.

In some embodiments, extending, or selectively extending, the CPS window in block <NUM> can include the operations of sub-block <NUM>, where when the portion of the active time is less than the first duration, the UE can extend the CPS window to outside the active time into an inactive time, such that the portion of the active time is extended to at least the first duration. Here the portion of the active time is extended by the UE turning on its SL receiver outside its SL-DRX Active Time, i.e. when in SL-DRX Inactive Time, so that it can perform sensing. In this way, the time during which the UE's SL receiver is active increases, i.e. it is extended, and then the portion of time during which the UE's SL receiver is active that overlaps with the remaining PDB associated with the SL transmission is also extended. This overlap corresponds to, or is denoted, the extended portion of the active time. During the extended portion of the active time, CPS is performed for at least CPSWmin and selection of resources is performed after CPS for at least RSWmin. <FIG> shows an example of these embodiments.

In some embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration of at least CPSWmin starting at the beginning of the portion of the active time while selection of resources is performed after CPS, for a duration of RSWmin until the end of the portion of the active time. <FIG> shows an example of these embodiments. In some of these embodiments, CPS is performed until the beginning of the selection of resources.

In other embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration of CPSWmin starting at the beginning of the portion of the active time, while selection of resources is performed after CPS for a duration of at least RSWmin, until the end of the portion of the active time. <FIG> shows an example of these embodiments.

In other embodiments, when the portion of the active time is not less than the first duration, CPS is performed for a duration greater than CPSWmin, starting at the beginning of the portion of the active time. Also, selection of resources is performed after CPS for a duration greater than RSWmin, until the end of the portion of the active time. <FIG> shows an example of these embodiments.

In various embodiments described above, the selection of resources is based on the CPS (e.g., CPS results or outcome), both of which are performed in block <NUM>.

In some embodiments, extending, or selectively extending, the CPS window when the portion of the active time is less than the first duration in block <NUM> can include the operations of sub-block <NUM>, where the UE can refrain from extending the CPS window when the trigger is received during an inactive time and a second duration between the time n and the beginning of the active time is less than CPSWmin. During the (non-extended) portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly (e.g., in block <NUM>) from a pool of SL resources. The extending of the CPS window when the portion of the active time is less than the first duration in block <NUM> may thus be selectively performed in that in case a second duration between the time n and the beginning of the active time is less than CPSWmin, e.g. in a situation when the trigger is received during an inactive time, the UE can refrain from extending the CPS window.

In other embodiments, extending, or selectively extending, the CPS window when the portion of the active time is less than the first duration in block <NUM> can include the operations of sub-block <NUM>, where the UE can refrain from extending the CPS window when a second duration between the time n and the end of the remaining PDB is less than CPSWmin plus RSWmin. During the (non-extended) portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly (e.g., in block <NUM>) from a pool of SL resources. <FIG> shows an example of these embodiments. In these embodiments, the extending of the CPS window when the portion of the active time is less than the first duration in block <NUM> may thus be selectively performed in that in case a second duration between the time n and the end of the remaining PDB is less than CPSWmin plus RSWmin, the UE can refrain from extending the CPS window.

In variants of these embodiments, the random selection of resources for the SL transmission (e.g., in block <NUM>) is further based on the UE's channel occupancy ratio (CR) not exceeding a threshold.

In some embodiments, extending, or selectively extending, the CPS window when the portion of the active time is less than the first duration in block <NUM> can include the operations of sub-block <NUM>, where the UE can refrain from extending the CPS window when the portion of the active time is less than RSWmin. During the portion of the active time, CPS is not performed and resources for the SL transmission are selected randomly from a pool of SL resources. In some of these embodiments, the selection of resources is performed randomly regardless of whether the CPS window can be extended such that CPS can be performed for at least CPSWmin. Thus, the extending of the CPS window when the portion of the active time is less than the first duration in block <NUM> may be selectively performed in that when the portion of the active time is less than RSWmin, the UE can refrain from extending the CPS window.

Although various embodiments are described above in terms of methods, techniques, and/or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and/or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc..

<FIG> shows an example of a communication system <NUM> in accordance with some embodiments. In the example, the communication system <NUM> includes a telecommunication network <NUM> that includes an access network <NUM>, such as a radio access network (RAN), and a core network <NUM>, which includes one or more core network nodes <NUM>. The access network <NUM> includes one or more access network nodes, such as network nodes 1510a and 1510b (one or more of which may be generally referred to as network nodes <NUM>), or any other similar 3GPP access node or non-3GPP access point. The network nodes <NUM> facilitate direct or indirect connection of UEs, such as by connecting UEs 1512a-d (one or more of which may be generally referred to as UEs <NUM>) to core network <NUM> over one or more wireless connections.

In some examples, the UEs <NUM> are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network <NUM> on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network <NUM>. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e., being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

In the example, the hub <NUM> communicates with the access network <NUM> to facilitate indirect communication between one or more UEs (e.g., UE 1512c and/or 1512d) and network nodes (e.g., network node 1510b). In some examples, the hub <NUM> may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub <NUM> may be a broadband router enabling access to the core network <NUM> for the UEs. As another example, the hub <NUM> may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes <NUM>, or by executable code, script, process, or other instructions in the hub <NUM>. As another example, the hub <NUM> may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub <NUM> may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub <NUM> may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub <NUM> then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub <NUM> acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy IoT devices.

The hub <NUM> may have a constant/persistent or intermittent connection to the network node 1510b. The hub <NUM> may also allow for a different communication scheme and/or schedule between the hub <NUM> and UEs (e.g., UE 1512c and/or 1512d), and between the hub <NUM> and the core network <NUM>. In other examples, the hub <NUM> is connected to the core network <NUM> and/or one or more UEs via a wired connection. Moreover, the hub <NUM> may be configured to connect to an M2M service provider over the access network <NUM> and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes <NUM> while still connected via the hub <NUM> via a wired or wireless connection. In some embodiments, the hub <NUM> may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 1510b. In other embodiments, the hub <NUM> may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1510b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

<FIG> shows a UE <NUM> in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by 3GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

UE <NUM> may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink (SL) communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In such case, certain components of UE <NUM> (e.g., communication interface <NUM>) can include functionality needed to communicate directly with other UEs.

In other examples, UE <NUM> may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device.

The processing circuitry <NUM> may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, fieldprogrammable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above.

Each transceiver may include a transmitter <NUM> and/or a receiver <NUM> appropriate to communicate with an access network and/or with other UEs (e.g., via optical, electrical, frequency allocations, and so forth).

In the illustrated embodiment, communication functions of the communication interface <NUM> may include cellular communication (including uplink, downlink, and sidelink), Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof.

A UE, when in the form of an Internet of Things (IoT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an IoT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an IoT device comprises circuitry and/or software in dependence of the intended application of the IoT device in addition to other components as described in relation to the UE <NUM> shown in <FIG>.

In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone's speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone's speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

<FIG> shows a network node <NUM> in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeB s (gNBs)).

The memory <NUM> may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions (collectively denoted computer program product 1704a) capable of being executed by the processing circuitry <NUM> and utilized by the network node <NUM>.

Applications <NUM> (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

Hardware <NUM> includes processing circuitry, memory that stores software and/or instructions (collectively denoted computer program product 1904a) executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers <NUM> (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1908a and 1908b (one or more of which may be generally referred to as VMs <NUM>), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer <NUM> may present a virtual operating platform that appears like networking hardware to the VMs <NUM>.

Hardware <NUM> may be implemented in a standalone network node with generic or specific components. Hardware <NUM> may implement some functions via virtualization. Alternatively, hardware <NUM> may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration <NUM>, which, among others, oversees lifecycle management of applications <NUM>. In some embodiments, hardware <NUM> is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system <NUM> which may alternatively be used for communication between hardware nodes and radio units.

<FIG> shows a communication diagram of a host <NUM> communicating via a network node <NUM> with a UE <NUM> over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 1512a of <FIG> and/or UE <NUM> of <FIG>), network node (such as network node 1510a of <FIG> and/or network node <NUM> of <FIG>), and host (such as host <NUM> of <FIG> and/or host <NUM> of <FIG>) discussed in the preceding paragraphs will now be described with reference to <FIG>.

One or more of the various embodiments improve the performance of OTT services provided to the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, embodiments can balance energy savings of SL-DRX with the need for reliable sensing to facilitate SL resource selection. Embodiments can improve reliability of the SL transmission due to the extended sensing operation in case the UE is in DRX, reduce energy consumption compared to a full-sensing operation, and trigger extended sensing operation as needed. Embodiments also provide a common UE behavior regarding the minimum contiguous sensing window which must be met irrespective of SL-DRX configuration or UE implementation, thereby improving overall system performance by reducing collisions caused by inadequate sensing. In this manner, embodiments increases the value of OTT services that rely on SL communications to both end users and services providers.

In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection <NUM> between the host <NUM> and UE <NUM>, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host <NUM> and/or UE <NUM>. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the 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 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection <NUM> may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node <NUM>. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host <NUM>. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or 'dummy' messages, using the OTT connection <NUM> while monitoring propagation times, errors, etc..

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Various exemplary embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and/or electronic devices and can include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Claim 1:
A method performed by a user equipment, UE, configured for sidelink, SL, communication with one or more other UEs in a wireless network, the method comprising:
while operating in SL discontinuous reception, SL-DRX, comprising a plurality of active
times during which the UE's SL receiver is active and a plurality of inactive times during which the UE's SL receiver is inactive, receiving (<NUM>), at a time n, a trigger to select resources for a SL transmission;
the method characterized by extending (<NUM>) a contiguous partial sensing, CPS, window after the trigger at time n when a portion of an active time is less than a first duration, wherein:
the portion of the active time corresponds to an overlap of the active time with a remaining packet delay budget, PDB, associated with the SL transmission, and
the first duration comprises a minimum contiguous partial sensing window, CPSWmin, followed by a minimum resource selection window, RSWmin; and
performing (<NUM>) at least one of the following during the portion of the active time:
contiguous partial sensing, CPS, of resources; and selection of resources for the SL transmission.