Patent Description:
In NR, a WTRU may operate using bandwidth parts (BWPs) in a carrier. First, a WTRU may access a cell using an initial BWP. It may then be configured with a set of BWPs to continue operation.

Channel access in an unlicensed frequency band may use a Listen-Before-Talk (LBT) mechanism, which is typically mandated independently of whether the channel is occupied or not. For frame-based systems, LBT may be defined by one or more of the following parameters : a Clear Channel Assessment (CCA) time, a Channel Occupancy Time (COT), an idle period, a fixed frame period, a short control signaling transmission time, and a CAA (Capacity Allocation Acknowledgement) energy detection threshold. For load-based systems (e.g., transmit/receive structure may not be fixed in time), LBT may be parameterized by a number N corresponding to the number of clear idle slots in extended Clear Channel Assessment (CCA) instead of a fixed time period before a device may access the channel. N may be selected randomly within a range.

The listen-before-talk (LBT) procedure is defined as a mechanism by which a WTRU applies a CCA check before using the channel. The CCA utilizes at least energy detection to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear, respectively.

Clear Channel Assessment (CCA) may be performed on contiguous PRBs (Physical Resource Blocks) in multiples of <NUM> (or number of PRBs). A WTRU may be configured with a set of BWPs that are composed of one or more <NUM> sub-bands. When the network acquires the channel, it may indicate to the WTRU the start of the COT. However, the WTRU further needs to determine which sub-bands (e.g., sets of PRBs) of the frequency carrier were grabbed and further determine what active DL BWPs and/or portions of configured DL BWPs are acquired by the network.

Also, if the regular uplink (RUL) in a cell is assessed as unreliable for an uplink transmission, the WTRU may switch its active UL carrier to a supplementary uplink carrier (SUL).

Thus, methods for bandwidth part (BWP) and supplementary uplink (SUL) operation in wireless systems are needed.

The document <NPL>, discloses that BWP concept allows handling the issue of partial subband availability for wideband NR-U carrier. The gNB can configure multiple BWPs for each UE, where these BWPs are configured so as to avail the wideband carrier in a number of combinations of partial subbands being available. These UEs can initially be configured for the default bandwidth part which is wide and may potentially encompass the whole wideband carrier. When the gNB has its LBT passing on a subset of subbands of the wideband carrier, it can switch the BWPs for the UEs so that it corresponds to the available subbands.

The document <NPL>, proposes that the frequency-domain location of the CORESET should be adjusted according to the results of LBT. Preamble can be used to indicate the location of the CORESET.

Methods are described herein for BWP and SUL operation in wireless systems, especially in systems using a shared spectrum. The term shared spectrum may refer to any spectrum that is shared between multiple operators and/or multiple technologies (e.g., 3GPP, WiFi, radar, satellite, etc.), and may include lightly licensed spectrum, licensed spectrum that is shared between operators and/or unlicensed spectrum. The terms shared and unlicensed may be used interchangeably in this disclosure.

In one exemplary embodiment, a wireless transmit/receive unit (WTRU) may receive information related to an upcoming channel occupancy time (COT) and use the received information to determine at least one resource for the operation of the WTRU during the COT. The received information may include signaling information of an occupied channel in a frequency domain during the COT. The received information may also include a duration of the COT. The at least one resource may include a control resource set (CORESET) within which the WTRU shall operate. The WTRU may monitor at least one frequency band in order to detect the information related to an upcoming channel occupancy time. The WTRU may select a downlink bandwidth part (DL BWP) for message reception. The selection may be based on at least one measurement performed by the WTRU. The WTRU may trigger a measurement report when at least one measurement associated with a DL BWP satisfies a criterion. The WTRU may switch from one DL BWP to another DL BWP. It may then transmit a message indicating the switch. The WTRU may also select an uplink bandwidth part (UL BWP) for message transmission. At least one inactivity timer may be configured in the WTRU for at least one DL BWP. The WTRU may deactivate a DL BWP when its corresponding inactivity timer expires.

In another exemplary embodiment, a WTRU operating in a wireless network may transmit data on a first uplink carrier. It may trigger a switch from the first uplink carrier to a second uplink carrier based on at least one condition of the network and transmit data on the second uplink carrier.

A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawing, wherein like reference numerals in the figures indicate like elements, and wherein:.

The communications system <NUM> may also include a base station 114a and/or a base station 114b.

It will be appreciated that the WTRU <NUM> may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

The MME <NUM> may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN <NUM> via an S1 interface and may serve as a control node.

The SGW <NUM> may perform other functions, such as anchoring user planes during intereNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

Although the WTRU is described in <FIG> as a wireless terminal, it is contemplated in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

11n, <NUM>. 11ac, <NUM>. 11af, and <NUM>. In the example of <NUM> ah, the primary channel may be <NUM> wide for STAs (e.g., MTC type devices) that support (e.g., only support) a <NUM> mode, even if the AP, and other STAs in the BSS support <NUM>, <NUM>, <NUM>, <NUM>, and/or other channel bandwidth operating modes.

11ah is <NUM> to <NUM> depending on the country.

For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and/or receive signals from the gNBs 180a, 180b, 180c.

Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized.

A PDU session type may be IP-based, non-IP based, Ethernetbased, and the like.

The UPF 184a, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the ON 185a, 185b.

In view of <FIG>, and the corresponding description of <FIG>, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME <NUM>, SGW <NUM>, PGW <NUM>, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, ON 185a-b, and/or any other device(s) described herein, may be performed by one or more emulation devices (not shown).

The term network in the following description may refer to one or more gNBs which in turn may be associated with one or more Transmission/Reception Points (TRPs) or any other node in the radio access network.

The term shared spectrum may refer to any spectrum that is shared between multiple operators and/or multiple technologies (e.g., 3GPP, WiFi, radar, satellite etc.) and may include lightly licensed spectrum, licensed spectrum that is shared between operators and/or unlicensed spectrum. The terms shared spectrum and unlicensed spectrum may be used interchangeably in this disclosure.

Next generation air interfaces, including further evolution of LTE Advanced Pro and a New Radio (NR), are expected to support a wide range of use cases with varying service requirements (e.g., low overhead low data rate power efficient services (mMTC), ultra-reliable low latency communication (URLLC) and high data rate enhanced mobile broadband services (eMBB)), for diverse WTRU capabilities (low power low bandwidth WTRUs, WTRUs capable of very wide bandwidth, e.g., <NUM>, WTRUs support for high frequencies e.g., ><NUM> etc.), with different spectrum usage models (e.g., licensed, unlicensed/shared etc.), under various mobility scenarios (e.g., stationary/fixed, high speed trains etc.) using an architecture that is flexible enough to adapt to diverse deployment scenarios (e.g., standalone, non-standalone with assistance from a different air interface, centralized, virtualized, distributed over ideal/non-ideal backhaul etc.).

In NR, a WTRU may operate using bandwidth parts (BWPs) in a carrier spectrum. First, a WTRU may access the cell using an initial BWP. It may then be configured with a set of BWPs to continue operation. At any given moment, a WTRU may have at least one active BWP. Each BWP may be configured with a set of Control Resource Sets (CORESETs) within which a WTRU may blind decode Physical Downlink Control Channel (PDCCH) candidates for scheduling, among other things.

Furthermore, NR supports variable transmission duration and feedback timing. With variable transmission duration, a Physical Downlink Shared Channel (PDSCH) or Physical Uplink Shared Channel (PUSCH) transmission may occupy a contiguous subset of symbols of a slot. With variable feedback timing, the Downlink Control Information (DCI) for a DL assignment may include an indication for the timing of the feedback for the WTRU, e.g., by pointing to a specific Physical Uplink Control Channel (PUCCH) resource.

NR may support two types of PUCCH resources, a short PUCCH and a long PUCCH. The former may be transmitted using <NUM> or <NUM> OFDM symbols, while the latter may use up to <NUM> OFDM symbols. Each PUCCH type may have multiple formats which may depend on the type and/or size of corresponding payload.

Beamforming may be used to compensate for increased path-loss at higher frequencies (e.g., ><NUM>). A large number of antenna elements may be used to achieve higher beamforming gain.

Analog and/or hybrid beamforming may be used to reduce implementation costs by reducing the number of RF chains. Typically, analog/hybrid beams may be multiplexed in time. Beamforming may be applied for Sync and/or Physical Broadcast Channel (PBCH) and/or Control channels to provide cell wide coverage.

Different reference signals may be defined for beam management in the DL and UL. For example, the downlink beam management may use Channel State Information-Reference Signal (CSI-RS), Demodulation Reference Signal (DMRS), synchronization signal, or similar. For example, the uplink beam management may use Sounding Reference Signal (SRS), DMRS, Random Access Channel (RACH), or similar.

Operation in an unlicensed frequency band may be subject to some limits on the Transmit Power Control (TPC), the RF output power and power density given by the mean Effective Isotropic Radiated Power (EIRP), and the mean EIRP density at the highest power level. It may further be subject to requirements on the transmitter out of band emissions. Such may be specific to bands and/or geographical locations.

Operation may be further subject to requirements on the Nominal Channel Bandwidth (NCB) and the Occupied Channel Bandwidth (OCB), which may be defined for unlicensed spectrum in the <NUM> region. The Nominal Channel Bandwidth, i.e., the widest band of frequencies inclusive of guard bands assigned to a single channel, shall be at least <NUM> at all times in NR. The Occupied Channel Bandwidth, i.e., the bandwidth containing <NUM> % of the power of the signal, shall be between <NUM> % and <NUM> % of the declared Nominal Channel Bandwidth. During an established communication, a device may be allowed to operate temporarily in a mode where its Occupied Channel Bandwidth may be reduced to as low as <NUM> % of its Nominal Channel Bandwidth with a minimum of <NUM>.

Channel access in an unlicensed frequency band may use a Listen-Before-Talk (LBT) mechanism. LBT is typically mandated independently of whether the channel is occupied or not.

For frame-based systems, LBT may be defined by (<NUM>) a Clear Channel Assessment (CCA) time (e.g., ~<NUM>), (<NUM>) a Channel Occupancy Time (COT) (e.g., minimum <NUM>, maximum <NUM>), (<NUM>) an idle period (e.g., minimum <NUM>% of channel occupancy time), (<NUM>) a fixed frame period (e.g., equal to the channel occupancy time + idle period), (<NUM>) a short control signaling transmission time (e.g., maximum duty cycle of <NUM>% within an observation period of <NUM>), and (<NUM>) a Capacity Allocation Acknowledgement (CAA) energy detection threshold.

For load-based systems (e.g., transmit/receive structure may not be fixed in time), LBT may be parameterized by a number N corresponding to the number of clear idle slots in extended CCA that must be detected before a device may access the channel instead of the fixed frame period. N may be selected randomly within a range.

Deployment scenarios may include different standalone NR-based operations, different variants of dual connectivity operation (e.g., EN-DC (E-UTRAN New Radio - Dual Connectivity) with at least one carrier operating according to the LTE radio access technology (RAT) or NR DC with at least two sets of one or more carriers operating according to the NR RAT), and/or different variants of Carrier Aggregation (CA), e.g., possibly also including different combinations of zero or more carriers of each of LTE and NR RATs.

For example, for LTE, the following functionalities were considered for a License Assisted Access (LAA) system:.

3GPP is expected to study the support for operation in unlicensed bands in Release <NUM>. Per a study item description for NR unlicensed (NR-U), one may refer to<NPL>. The objective is to study NR-based operation in unlicensed spectrum, including initial access, Scheduling/Hybrid Automatic Repeat Request (HARQ), and mobility, along with coexistence methods with LTE-LAA and other incumbent RATs. Some scenarios under study include NR-based LAA cell connected with an LTE or NR anchor cell, as well as NR-based cell operating standalone in unlicensed spectrum.

NR unlicensed (NR-U) may support that a serving cell can be configured with bandwidth larger than <NUM>. The following options are considered for BWP operation in NR-U. For DL operation, the following options for BWP-based operation within a carrier with bandwidth larger than <NUM> may be considered:.

Multiple active BWPs and LBT mechanisms in a given frequency carrier may impact BWP and SUL operation as defined initially in NR. Thus, some procedures may be adapted to accommodate this. In particular, procedures may be defined to take into account the plurality of active BWPs, the unavailability of sub-bands and to make use of the diverse available frequency carriers or portions with different associated channel characteristics or regulations.

Additionally, new measurements may assist the network in the configuration of the BWP and/or allow the WTRU to select frequency carriers and/or BWPs to successfully receive downlink control messages or perform uplink transmissions.

A first aspect of the present disclosure concerns the indication of the channel acquisition in the frequency domain. CCA may be performed on contiguous Physical Resource Blocks (PRBs) in multiples of <NUM> (or multiples of PRBs). A WTRU may be configured with a set of BWPs that are composed of one or more <NUM> sub-bands. When the network acquires the channel, it may transmit a signal to the WTRU indicating the start of the COT (hereinafter termed the pre-signal). However, the WTRU may further need to determine which sub-bands (e.g., which set(s) of PRBs) of the frequency carrier were grabbed and further determine what active DL BWPs and/or portions of configured DL BWPs are acquired by the network.

Moreover, further to signaling the start of the COT and the corresponding acquired bandwidth, it may be beneficial to also inform the WTRU of the duration of the COT.

Furthermore, although the transmission of the pre-signal indicating the start of the COT facilitates its detection with low complexity and is less power consuming than frequent PDCCH monitoring, the WTRU may be required to monitor multiple frequency locations to receive this pre-signal, especially under multiple active DL BWPs operation. To facilitate its detection while reducing the effort of the WTRU, some procedure may need to be defined.

The occupied channel structure may include resources in frequency domain, time domain, and/or spatial domain. The occupied channel may be determined as a function of the medium obtained by a successful channel access procedure (e.g., LBT). And thus, the channel access procedure may imply how much bandwidth is occupied in addition to the timing and duration of when the channel is acquired.

A WTRU may monitor for the presence of a pre-signal transmitted to the WTRU that signals the configuration of an upcoming COT. Such pre-signal may be transmitted to one or more WTRUs in the system.

This pre-signal may either contain information about the gNB's channel acquisition (e.g., time/frequency/spatial resources) or indicate to the WTRU that it has to monitor one or more PDCCHs to receive further downlink control information about an activation of a BWP or an acquisition of channel subbands.

The pre-signal may be provided implicitly via another signal. For example, a sequence used for a Reference Signal (RS) may provide the WTRU with the necessary parameters to operate on a COT. Such parameters may include the PDCCH to be monitored.

In another solution, the pre-signal may be provided explicitly, such as in a bitmap or a short transmission (e.g., one bit information). For example:.

To signal the sub-bands grabbed by the network, the subbands may be indexed from <NUM> to x throughout the frequency carrier, e.g., sub-band index <NUM> corresponding to the first LBT sub-band and subband index x corresponding to the last LBT sub-band in the serving carrier.

The WTRU may further receive in the corresponding PDCCH a DCI for LBT success indication in the DL sub-bands. A DCI may indicate to the WTRUs of the system the sub-bands that are activated (i.e. acquired by the network).

When a pre-signal as described is successfully received by the WTRU, the WTRU may start monitoring the corresponding CORESET and/or search space.

The embodiment of <FIG> represents an exemplary NR-U system with three example WTRUs, UE1, UE2 and UE3, in which the initial BWP, BWP0, is not acquired by the network. The UEs are configured with DL BWPs containing the frequency locations where a pre-signal may be received, i.e. where the LBT is successful at the network. Thus, UE1 and UE2 may be configured with DL BWP1 containing the frequency locations where pre-signal <NUM> may be received, while UE3 is configured with DL BWP1 containing the frequency locations where pre-signal <NUM> may be received (note that each WTRU has its own distinct BWP indices, i.e., the BWP indexed as BWP1 for UE1 may be a different BWP than the BWP indexed as BWP1 for UE2). Pre-signals indicating the start of the COT are transmitted to the WTRUs. They include a first pre-signal, Pre-signal <NUM>, transmitted in LBT sub-band <NUM> and a second pre-signal, Pre-signal <NUM>, transmitted in LBT sub-band <NUM>. For UE1 and UE2, the channel is deemed acquired in each UE's respective BWP1 as determined from the reception of pre-signal <NUM>, while for UE3, the channel is deemed acquired in its BWP1 as determined from the reception of pre-signal <NUM>. Thus, according to an exemplary mapping, UE1 and UE2 are configured with CORESET1 located in sub-band <NUM> as determined from the reception of pre-signal <NUM> and UE3 is configured with CORESET2 located in sub-band <NUM> as determined from the reception of Pre-signal <NUM>. All the WTRUs may be configured with a search space (e.g. common search space) to receive a DCI indicating the acquisition of sub-band1, sub-band2, sub-band6, sub-band7.

<FIG> shows an embodiment in which WTRUs may detect a pre-signal transmission in BWPs other than the initial BWP. A WTRU may monitor CORESETs and/or search spaces in a secondary set of BWPs (e.g., a configured BWP, possibly not including the initial DL BWP) if the WTRU has not received a pre-signal in its initial DL BWP. For example, the WTRU may monitor an initial DL BWP (BWP0) and only upon not receiving a pre-signal on this initial DL BWP, the WTRU may begin monitoring the second set of BWPs. The set of CORESETs or BWPs to monitor may be determined by the WTRU as a function of time and/or the location of the initial DL BWP.

The WTRU may assess the correspondence between LBT sub-bands and the configured BWPs and may be able to determine the configured BWPs or portions of BWPs acquired by the network. As in the example of <FIG>, UE1 may determine that a corresponding portion of DL BWP1 is acquired by the network, while UE2 may determine that its whole BWP1 is successfully acquired.

The duration of the COT may further be signaled to the WTRU either explicitly or implicitly.

The explicit indication may, for example, be that the first set of bits (e.g., first x bits) of the pre-signal may correspond to the LBT sub-bands indication as described above, and the second set of bits (e.g., last y bits) may correspond to the duration of the COT (e.g., number of slots of the COT).

Alternately, the duration of the COT may be implicitly signaled, for example, through a parameter of the pre-signal. For example, the duration of the pre-signal in OFDM symbols may be mapped to the duration of the COT. For example, one OFDM symbol of pre-signal duration may correspond to a certain number of OFDM symbols in the COT.

The pre-signal indicating the start of a COT and/or set of acquired LBT sub-bands by gNBs may be one or a combination of the following signals:.

The WTRU may be configured with multiple CORESETs and search spaces for the System Information Block (SIB) acquisition over the entire frequency carrier. If the pre-signal is received, this may indicate to the WTRU to monitor one or more CORESETs where the SIB may be transmitted.

A pre-signal, or COT preamble, may additionally be used to indicate the start of a gNB acquired COT (or DL burst) or may be contained in a signal used to indicate the start of a gNB acquired COT (or DL burst).

To avoid the need to monitor for a pre-signal in multiple frequency locations, the WTRU may expect to receive the pre-signal in some pre-defined frequency locations. This may reduce the pre-signal detection complexity for the WTRU and may reduce the need for a cell to transmit pre-signals in multiple frequency locations. For example, the WTRU may expect to receive the pre-signal in the sub-band corresponding to the initial DL BWP.

<FIG> illustrates an embodiment with two WTRUs, UE1 and UE2, in the case in which the acquired channel by each WTRU contains the initial BWP which may be common to all the WTRUs in the system, e.g., BWP0. In this case, UE1 and UE2 may receive the pre-signal in the initial active DL BWP(s), BWP0. UE1 and UE2 may be configured with a CORESET (CORESET0) and a common search space to receive a Downlink Control Information (DCI) indicating the acquired sub-bands, i.e., sub-band <NUM>, during the signaled COT. The WTRUs may also receive the System Information (SI) within the acquired initial DL BWP indicating the acquired sub-bands. As the WTRUs are configured with multiple active DL BWPs, they may expect to receive a pre-signal in different frequency locations, i.e. different DL BWPs, based on where the successful LBT may be performed at the transmitter side. Thus, UE1 and UE2 also monitor BWP1 and BWP2 for this purpose. Moreover, portions of the BWPs may be discarded (such as BWP1 and a portion of BWP2 for UE1) only for the duration of the COT. This does not prevent the WTRUs from receiving an indication of another COT for another set of sub-bands in these DL BWPs.

If the WTRU has received a DCI for DL BWPs activation during a COT (i.e., upon receiving a pre-signal indicating the start of a COT), the WTRU may consider that the active DL BWPs are acquired by the gNB.

In one exemplary embodiment, a WTRU monitors all its active DL BWPs for pre-signal reception. For instance, the WTRU may receive a pre-signal in one DL BWP that may activate or trigger the monitoring of the associated CORESET and search space (e.g., the CORESET in the same DL BWP where the pre-signal was received).

For example, with reference again to <FIG>, UE <NUM>, UE2 and UE3 all monitor a common BWP, BWP0. UE1 also monitors two other BWPs, namely, its BWP1 and BWP2. UE2 also monitors one other BWP, namely, its BWP1. Finally, UE3 also monitors one other BWP, its BWP1. Note that BWP1 for UE1 and BWP1 for UE2 overlap with each other. UE1 and UE2 both receive the pre-signal, Pre-signal <NUM>, in their respective BWPs1. Consequently, UE1 and UE2 start monitoring the associated CORESET1 for DCI reception. However, UE3 is not configured with a DL BWP where the first pre-signal, Pre-signal <NUM>, is transmitted. Thus, UE3 receives another pre-signal, Pre-signal <NUM>, in its active DL BWP1 that triggers the monitoring of the CORESET2.

The pre-signal may be transmitted at a time offset from the first PRB of the CORESET, for example, a given number of PRBs before or after the first PRB. If the WTRU receives such pre-signal, the WTRU may start monitoring the corresponding PDCCH. In the corresponding PDCCH, the WTRU may receive a DCI for BWP activation or sub-bands acquisition.

For example, the WTRU may be configured with a mapping of PRBs to BWPs. If the pre-signal is received in a set of PRBs mapped to a BWP, the WTRU may consider the BWP as activated. Such a mapping may be per BWP. As such, a pre-signal sent on a first BWP may point to a second BWP being activated.

A WTRU may be configured to determine the BWP (or the number of BWPs) to monitor for pre-signal based on predefined rules. For example, the WTRU may be configured to monitor a pre-signal in a targeted BWP (e.g., current active BWP or the BWP in which it received the most recent DL signal). If a pre-signal is not detected in that targeted BWP (possibly for a configured period of time), then the WTRU may be configured to monitor the pre-signal in one or more other BWP(s) (e.g., in any of the BWPs that were active in the past X ms). Upon failure to detect the pre-signal in previous active BWPs, the WTRU may add initial/default BWPs to the list of BWPs to monitor for pre-signal. Upon failure to detect the pre-signal (possibly for a configured period of time), the WTRU may monitor the pre-signal in all the configured BWPs. If a pre-signal is not detected in any of the configured BWPs (possibly for a configured period of time), the WTRU may include the whole carrier bandwidth for pre-signal monitoring.

A WTRU may be configured with a window to monitor for the pre-signal having a starting time, a time duration, and a periodicity. Such configuration may be received by an RRC configuration and may be applicable to the WTRU when it is in connected mode. The monitoring may only be performed outside of a DL burst. The time window may comprise multiple occasions, each corresponding to a monitoring time and duration of one indicated sub-band. The first occasion of the window may for example be used to monitor a specific sub-band, the second occasion another sub-band, etc..

In another solution, the monitoring of sub-bands may be incremental in the time window. An example of an incremental monitoring process implemented by a WTRU is depicted in <FIG>, where the first occasion of the window (w1 in the left) is dedicated to the monitoring of sub-band3, the second monitoring occasion (w21 and w22 in the middle) is dedicated to the monitoring of sub-band1 and subband3, and finally the third monitoring occasion of the window (w31, w32 and w33 in the right) is dedicated to the monitoring of sub-band1, sub-band3 and sub-band4. In the represented example, a pre-signal is detected at the second monitoring occasion at sub-band3 in the active DL BWP0, that triggers the monitoring of the CORESET0.

Upon detecting a pre-signal in any configured or signaled DL BWP or sub-band, the WTRU may activate the corresponding DL BWP or sub-band. This activation may be part of a two-step method in combination with the DL BWP activation received in a DCI. For example, in a first step, a UE may be indicated to switch DL BWP to a target DL BWP. The UE may then attempt to receive a pre-signal indicating that the target DL BWP is indeed activated. In another method, the activation of a DL BWP by pre-signal detection may override the indicated target DL BWP determined from a previously received DCI indication. In the case of overriding activation, the WTRU may deactivate the DCI activated DL BWP and activate the DL BWP where the pre-signal is detected. DL BWP switching via pre-signal detection may only be applicable outside of a DL burst. During a DL burst, on the other hand, the WTRU may only activate or deactivate BWPs based on (<NUM>) a DCI message, (<NUM>) a RRC message, (<NUM>) fallback due to inactivity timer expiry, and/or (<NUM>) BWP linkage based switching.

Upon detecting a pre-signal indicating that two or more BWPs are acquired, the WTRU may select a BWP (e.g., consider such acquired BWP as active) from the set or a subset of BWPs (possibly up to a maximum number of simultaneous active BWPs) to receive the PDCCH, based on prioritization rules, such as:.

In an alternative monitoring scheme, a WTRU may determine a new BWP as an aggregate of all the BWPs (or sub-bands) indicated as acquired. For example, the WTRU may determine a BWP for monitoring as the frequency range that accommodates at least the set of acquired sub-bands. For instance, in order to monitor one contiguous frequency range for simplicity, the BWP may monitor subbands that span all of the acquired BWPs but includes additional, contiguous BWPs that are not indicated as acquired. In another example, the WTRU may determine a new BWP as a set of contiguous acquired BWPs (or sub-bands), e.g., the largest set thereof.

<FIG> is a flowchart illustrating operation of a WTRU for obtaining information about resources related to an upcoming COT in accordance with an exemplary embodiment.

At <NUM>, the WTRU may monitor for the presence of a pre-signal signaling the configuration of an upcoming COT in one or more BWPs configured for the WTRU.

At <NUM>, after receiving the pre-signal, the WTRU may determine a CORESET that it shall monitor, for example, by using a mapping between the PRB or set of PRBs in the BWP in which the pre-signal was received and a CORESET index.

At <NUM>, the WTRU may decode a Physical Downlink Control Channel (PDCCH) within the determined CORESET.

A second aspect of the present disclosure concerns the bandwidth part (BWP) linkage for the random access (RA) procedure. NR may use one-to-one BWP linkage limitation. In NR, when the WTRU initiates a Random Access (RA), it may switch its active DL BWP to the DL BWP with the same BWP-ld as the active UL BWP. This linkage was initially introduced for Contention Based Random Access (CBRA) for the network to know where to transmit a Random Access Response (RAR) when it receives a preamble, i.e., Msg1 (RACH request) of the RA procedure. The linkage was extended to Contention Free Random Access (CFRA) for consistency. However, this static linkage may not be applicable to NR-U.

In NR-U, the linked DL BWP where the WTRU is expecting to receive the DL messages during a RA may be busy, while other configured DL BWPs may have been acquired by the network. Similarly, a WTRU's active UL BWP may be busy and the WTRU may need to switch its active UL BWP to transmit the preamble.

Thus, there is a need for a mechanism that would permit multiple active BWPs and the associated behavior for transmitting and receiving RA messages.

If the WTRU is configured with multiple active BWPs, the one-to-one BWP linkage introduced in NR may not be ideal. With multiple active DL BWPs, the reception of the DL messages during a RA may depend on the capability of the WTRU to monitor multiple PDCCHs at the same time or how the WTRU determines in which of the active DL BWPs it is expecting to receive the Random Access Response (RAR).

The following exemplary linkages may either be explicit linkages (e.g., an identifier, x, of UL BWP may be linked to an identifier, y, of DL BWP) or implicit. The linkage also may be at the level of LBT subband granularity, rather than BWP granularity. For the remainder of this text, BWP and LBT sub-band may be used interchangeably. For example, there may be a linkage between reception of a pre-signal in a first LBT sub-band and the selection of a second LBT sub-band for the transmission of a random access preamble. An implicit linkage may be that the Physical Random Access Channel (PRACH) resource or set of PRACH resources associated with an UL BWP are linked to a CORESET or search space configured in the DL BWP. In such a way, WTRUs configured with multiple overlapping DL BWPs are not required to switch their active DL BWP if it contains the CORESET associated with the linked uplink PRACH resource where the WTRU transmitted the preamble.

A first embodiment may be a one-to-many linkage, i.e. one UL BWP is linked to one or more DL BWPs.

According to an example, the WTRU may monitor multiple PDCCHs at the same time. Then, the WTRU may receive the RAR in one or multiple of the linked active DL BWPs. This may depend on the WTRU capability, e.g., the case of a WTRU with multiple RF chains.

According to an example, the WTRU may monitor control regions of one BWP at a time.

For example, the WTRU may perform a PDCCH monitoring sweeping in time for RAR reception. The WTRU may be configured with a periodic window for PDCCH monitoring where a slot or a group of slots in the window are associated with PDCCH within a given DL BWP. The RAR timing in the corresponding DL BWP may further match the allocated time window.

For example, the WTRU may only monitor for the RAR in the sub-bands acquired by the gNB upon receiving a COT preamble. If multiple DL BWPs are activated, the WTRU may receive the RAR in the DL BWP with random access search space associated with the lowest frequency band. Alternately, the WTRU may determine the DL BWP where it may receive the RAR based on a function. Such function may use as input at least one of the frequency of the random access CORESET, the timing of the RA preamble transmission, or the timing of the associated Dedicated Reference Signal (DRS) or Synchronization Signal Block (SSB). The WTRU may also determine the DL BWP where it may receive the RAR based on the type of random access it is performing and on the configuration of associated parameters. For example, for beam failure recovery, among the linked active DL BWPs, the WTRU may monitor a DL BWP configured with a recovery search space.

According to an example, the WTRU may indicate to the network its preference among the configured active DL BWPs for DL message reception during the RA procedure. Such preference may be based on measurements performed by the WTRU on a set of resources contained in the active DL BWP to permit the network to be aware of possible hidden nodes, i.e., nodes that are visible to the WTRU but not to the transmitter that may perform the LBT. For example, a mapping of the preamble transmitted by the UE and DL BWPs may enable the WTRU to transmit a RA preamble associated with a DL BWP in which it prefers to receive the RAR. For example, a WTRU may be configured with Random Access Channel (RACH) occasions associated with each DL BWP.

A second embodiment may be a many-to-one linkage, i.e. multiple UL BWPs are linked to the same DL BWP.

If the WTRU is configured with multiple UL BWPs and DL BWPs, it may further be configured with a linkage between multiple UL BWPs and one DL BWP.

The WTRU may be configured with different types of linkage, but only activate the many-to-one linkage when it assesses that the channel associated with the DL BWP is acquired.

For example, this type of linkage may be applicable if a pre-signal for COT indication associated with the bandwidth of the linked DL BWP has been transmitted to the WTRU prior to the random-access initiation.

The WTRU may select any of the UL BWPs for preamble transmission and is expecting to receive the RAR and subsequent messages in the linked DL BWP. For example, the WTRU may select (e.g., autonomously select) the UL BWP based on a UL BWP selection rule. The rule may include at least one of: the UL BWP with the lowest channel occupancy (or channel occupancy below a threshold), the UL BWP with highest Reference Signal Received Quality (RSRQ), the UL BWP associated with a DRS/SSB, the UL BWP associated with a traffic type, the UL BWP indicated in a random access command. The WTRU may monitor the linked DL BWP for RAR and subsequent DL messages. The WTRU may also select the UL BWP based on measurement (e.g., Reference Signal Received Power (RSRP), RSRQ, Signal to Interference plus Noise Ratio (SINR), Received Signal Strength Indication (RSSI), Channel Occupancy (CO)) of one or a set of configured SSB and/or CSI-RS resources associated with the corresponding BWPs. The WTRU may also select the UL BWP based on the configuration of dedicated RACH resources, e.g., the WTRU may select the UL BWP with dedicated PRACH resources. The WTRU may also select the UL BWP based on the type of RA and configuration of the associated parameters. For example, for a beam failure recovery request, the WTRU may select the UL BWP configured with recovery resources. For example, for SI request, the WTRU may select the UL BWP configured with random access preambles and/or PRACH occasions for SI request.

According to another embodiment, the WTRU may select the UL BWP in which to perform RACH based on characteristics of the linked DL BWP(s). For example, the WTRU may be configured with PRACH resources in multiple UL BWPs. In order to determine which UL BWP to switch to and transmit the preamble, the WTRU may use the UL BWP/DL BWP linkage. For example, the WTRU may select the UL BWP(s) linked to the DL BWP(s) that was/were acquired by the gNB e.g., based on a reception of a pre-signal. If multiple DL BWPs are acquired, the WTRU may perform an UL BWP selection based on measurement results of the acquired DL BWP, e.g., the WTRU may select the UL BWP linked to the DL BWP with the highest measurement result (e.g., RSRQ). If an LBT on the selected UL BWP is not successful, the WTRU may transmit the preamble, e.g., Msg1, in any acquired UL BWP or sub-band. A mapping of the preamble and/or PRACH resources may permit a WTRU to indicate this fallback. A priority rule may be used to determine in which DL sub-band the gNB may then transmit the pre-signal and the WTRU may monitor for RAR, e.g., the lowest acquired sub-band in frequency.

If a linked DL BWP comprises only one sub-band, the WTRU may detect the pre-signal and may monitor the associated sub-band for RAR. If the linked DL BWP comprises more than one acquired subband (i.e. multiple detected pre-signals), the WTRU may be configured to monitor more than one sub-band for RAR in the linked DL BWP.

In another embodiment, the WTRU may be configured with an association between PRACH resources and/or preambles and sub-bands in the linked DL BWP to indicate in the preamble transmission the DL sub-band(s) where it may expect to receive the RAR.

If there are multiple active BWPs and the WTRU receives an indication of the COT structure of a current DL burst, the WTRU may report in Msg1 or Msg3 (RRC Connection Request) the sub-band identifier of the best BWP/sub-band to transmit DL messages. The determination of the best sub-band may be based on a sub-band measurement result. For example, it may be based on channel occupancy, to assist the network to determine the existence of hidden nodes.

According to a further embodiment, while multiple DL BWPs are acquired by the network based on successful LBT on multiple sub-bands, it may be beneficial to indicate to the WTRU where to receive the DL messages during a random access procedure. This indication may permit the WTRU to monitor the search space for RAR and Msg4 (Contention Resolution Message) in only one DL BWP. This may also permit the gNB to indicate to the WTRU which DL BWPs among the active DL BWPs are acquired by the network while a random access is ongoing. For example, if the COT associated with the DL BWP where the WTRU has received Msg2 (RAR) expires shortly and the network has acquired a sub-band in another DL BWP, it may be beneficial to indicate in Msg2 (RAR) that the subsequent messages will be received in the other DL BWP. For load balancing among multiple DL BWPs, it may also be beneficial to be able to signal another DL BWP for RA messages reception.

Similarly, when the WTRU is configured with multiple active DL BWPs, it may be beneficial to allow the WTRU to indicate the preferred DL BWP for RAR and subsequent messages (i.e. Msg4 and possibly other messages such as RRC messages, DCIs, SI, etc.) reception based on some criteria. This indication may, for example, be based on a measurement performed by the WTRU and may help attenuate the hidden nodes problem.

A third aspect of the present disclosure concerns BWP inactivity timer operation and associated behavior of the WTRU. Indeed, other BWP operation procedures, such as fallback to initial/default BWP when an inactivity timer expires, as agreed in NR, may not be applicable to NR-U. In particular, the inactivity timer may expire often due to an LBT failure, resulting in multiple fallbacks of the WTRUs in the system to the initial BWP (thus overcrowding this BWP). Additionally, the initial/default DL BWP may not be available due to LBT mechanisms. Hence, new mechanisms are desirable to specify the behavior of the WTRU in such cases. Finally, it has been considered beneficial to allow multiple active DL BWPs in NR-U. Hence, the inactivity timer operation in such case has to be properly defined.

The BWP inactivity timer may expire often due to LBT failure. Moreover, the current behavior in NR, wherein the UE switches to the initial/default downlink bandwidth part, may not be applicable since the initial/default DL BWP may not be acquired by the gNB (e.g., due to a high channel occupancy).

To operate under multiple active DL BWPs operation, different configurations of the BWP inactivity timer may be considered.

In one embodiment, the WTRU may be configured with a single inactivity timer for all active DL BWPs. If an additional DL BWP is activated to a WTRU, the inactivity timer may be restarted.

In another embodiment, the WTRU may be configured with an inactivity timer applicable to a set of one or more DL BWPs. The sets of DL BWPs may have resources that overlap at least one LBT subband. Upon expiration of an inactivity timer for a set of DL BWPs, the WTRU may consider that that DL BWP is inactive. Furthermore, if there are no other currently active DL BWPs, the WTRU may switch to (or activate) the initial DL BWP.

The BWP inactivity timer may start/re-start/stop/pause depending on the status of a COT signaled to the WTRU. Such a timer may be deemed a COT-duration based inactivity timer. For example, the WTRU may only run an inactivity timer for a DL BWP if there is an active COT in all, some, or at least one, of the LBT sub-bands associated with the DL BWP. If the above condition is not met, the WTRU may pause or suspend an inactivity timer for that DL BWP or set of DL BWPs. The WTRU may re-start a paused inactivity timer upon determination that all, some, or at least one, of the LBT sub-bands is acquired by the gNB (e.g. upon reception of a pre-signal).

The WTRU may maintain more than one timer. For example, on top of the regular BWP-specific inactivity timer as in NR, the WTRU may be configured with an additional timer for BWP inactivity during the COT (e.g. a COT-duration based inactivity timer). These two timers may further be associated with different behaviors of the WTRU at their expiry as described in the following paragraph. For example, the WTRU may maintain two BWP inactivity timers, one during a COT and one outside the COT, and may determine which one to use based on the detection of the pre- signal.

The COT-duration based inactivity timer associated with a DL BWP or a set of DL BWPs may start or re-start at the beginning of the COT. For example, the WTRU may start the timer when it has received a COT pre-signal or a DCI indicating the acquisition of the associated DL BWP. The WTRU may stop or pause or suspend the timer at the end of the COT, if the COT duration has been explicitly signaled. Otherwise, the WTRU may stop the timer at the end of the regulatory maximum channel occupancy time or any other predetermined duration.

If the WTRU is configured with more than one active DL BWP and if the BWP inactivity timer associated with one of the active DL BWPs expires, the WTRU may autonomously deactivate the corresponding DL BWP.

If the WTRU has only one active DL BWP, and an inactivity timer expires (e.g. if the COT-duration based inactivity timer expires but the regular inactivity timer is still running), the WTRU may switch to another configured DL BWP for which it has received an indication of channel acquisition (e.g., COT pre-signal). The determination of the target DL BWP may depend on any one or more of the following.

In one embodiment, if the WTRU has received a pre-signal/DCI indicating the start of a COT in a non-active DL BWP, the WTRU may switch its active DL BWP to this BWP.

In one embodiment, if multiple BWPs have been acquired by the gNB, the WTRU may switch to the DL BWP with the highest measured RSSI.

In one embodiment, if multiple BWPs have been acquired by the gNB, the WTRU may switch to the DL BWP with the highest number of best beams (e.g., above a pre-defined threshold).

If the WTRU has autonomously switched to a DL BWP other than the initial/default DL BWP, the WTRU may inform the network of the switch. For example, the WTRU may transmit an UL message (e.g., Uplink Control Information (UCI)) to indicate the new activated DL BWP.

A fourth aspect of the present disclosure concerns the selection of UL and DL BWPs for receiving and/or transmitting in an unlicensed environment. In NR-U, when multiple UL and DL BWPs are either available for receiving and/or transmitting, the WTRU may need to select the BWP to activate or to transmit an indication to the network regarding which DL BWP has to be used for DL transmission. This indication is especially beneficial to cope with the hidden node problems where a plurality of DL BWPs may have been acquired by the network, but one specific band may be more beneficial for a given WTRU (e.g., with regard to interference and/or channel conditions for the reception of DL messages).

The WTRU may be configured with BWP specific measurement events and reporting in order to assist the network with configuring the active DL BWPs and/or activating/de-activating BWPs.

A WTRU may be configured with one or a set of CSI-RS resources confined within a specific frequency band.

In one embodiment, one or a set of CSI-RS resources are configured over each of the configured DL BWPs.

In one embodiment, one or a set of CSI-RS resources are configured over each of the active DL BWPs.

In one embodiment, one or a set of CSI-RS resources are configured over each of the LBT subbands.

A WTRU may be further configured with a measurement event allowing the triggering of a measurement report when one CSI-RS or a set of configured CSI-RS resources satisfy a given measurement result criterion. This criterion may be any one of RSRP, RSRQ, SINR, RSSI, channel occupancy or any combination thereof.

In one embodiment, a measurement report may be triggered if a measured quantity or a combination of measured quantities associated with one DL BWP is above a threshold. For example, if the measured RSRP and RSSI of CSI-RS in any of the configured DL BWPs is above a threshold, a measurement report may be triggered.

A measurement report may be triggered if a measured quantity or a set of measured quantities associated with CSI-RS resources over one DL BWP is an offset better, e.g., a certain number of dB higher, than the measured quantity in resources over another configured DL BWP. For example, a report may be triggered if the RSSI associated with a set of CSI-RS resources over one non-active DL BWP is an offset lower, i.e., a certain number of dB lower, than the measured RSSI associated with CSI-RS resources over the active DL BWP.

If the WTRU has received an indication that a given BWP has been acquired by the network (e.g., COT pre-signal), the WTRU may report the measurements associated with CSI-RS resources in the associated DL BWPs.

The measurement report may include the measurement results associated with the BWP-specific measurement results.

A WTRU may only maintain or perform measurements on CSI-RS associated with a BWP upon being informed that such a BWP has been acquired by the gNB.

A fifth aspect of the present disclosure concerns the operation of supplementary uplink (SUL) and the fallback to SUL in NR-U. In NR-U, although the diversity of BWPs and associated LBT sub-bands in a wideband carrier may allow the network to increase the chance of channel acquisition and successful UL/DL transmissions, the channel may be loaded or experience a high level of interference due to sharing of the channel by different nodes potentially from different operators.

Supplementary uplink (SUL) has been introduced in NR to cope with the limited uplink coverage in high frequency scenarios, but an additional uplink carrier for UL transmission fallback may also be beneficial in an unlicensed environment where the channel in a regular carrier is shared by different uncoordinated nodes.

Selection of SUL based on the received power in the DL may also be impacted by the maintenance of a plurality of active DL BWPs by the WTRU, and a specific behavior may be needed to trigger the fallback to a more reliable uplink. Moreover, if LBT is performed per sub-band, different BWPs may experience different levels of interference and/or the reference signal used as path loss reference may not be transmitted at RA initiation.

In one embodiment, if the regular uplink (RUL) in a cell is assessed as unreliable for an uplink transmission, the WTRU may switch its active UL carrier to a supplementary uplink carrier (SUL).

The SUL may operate in any of the following deployment scenarios:.

The WTRU may need to estimate the DL reception of the cell to trigger the selection of SUL for a RA procedure. This estimation may be based on a path loss reference that can either be performed in a DL BWP or in a plurality of DL BWPs if the WTRU is configured in multiple configured BWPs.

The triggering condition may be based on measurements by the WTRU. In one embodiment, the WTRU may switch to the SUL based on one or a combination of the following conditions:.

The WTRU may be configured with a set of rules in order to evaluate the downlink signal quality and determine if a selection of SUL is needed.

In one embodiment, the WTRU may determine the DL reference path loss and link quality based on a measurement of any DL BWP where it has received an indication of successful LBT (e.g., based on a COT pre-signal reception as described).

In one embodiment, the WTRU may perform such evaluation based on a measurement of the DL BWP(s) linked to the configured active BWP(s) in RUL carrier. Such configuration may be specifically received by the WTRU in the Radio Resource Control (RRC) configuration. Such linkage may be based on the LBT sub-bands associated with the UL and DL BWPs. For example, to select SUL for its UL transmission, the WTRU may determine that a measurement result in the DL BWP(s) comprising the same LBT sub-band(s) as the active UL BWP(s) is below a threshold, Th.

In one embodiment, the WTRU may be configured with one or a set of reference signals associated with each UL BWP in the RUL carrier. The WTRU may select SUL if the measurement results of all reference signals are below a pre-defined threshold, or the WTRU may select SUL if the average measurement result of all reference signals associated with all the active UL BWPs is below a threshold, or the UE may select SUL if the reference signal associated with the UL BWP where it has successfully performed LBT is below a threshold.

<FIG> is a flowchart illustrating an embodiment of the operation of a WTRU for switching from a RUL to a SUL.

At <NUM>, the WTRU may be operating on a Regular Uplink Carrier (RUL) which may be in licensed or unlicensed spectrum. Furthermore, the WTRU may be continuously measuring a plurality of channel conditions.

At <NUM>, the WTRU, responsive to one or more measurements, may determine that the channel conditions have changed sufficiently to merit a possible switch from RUL to a Supplemental Uplink Carrier (SUL).

At <NUM>, in response to such determination, the WTRU may switch its active UL carrier to the SUL, which may be in the licensed or unlicensed spectrum.

At <NUM>, the WTRU may begin operating on the SUL.

Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, a read only memory (ROM), random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU <NUM>, UE, terminal, base station, RNC, or any host computer.

Moreover, in the embodiments described above, processing platforms, computing systems, controllers, and other devices containing processors are noted. These devices may contain at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed.

One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the representative embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (e.g., but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost vs. efficiency tradeoffs. There may be various vehicles by which processes and/or systems and/or other technologies described herein may be effected (e.g., hardware, software, and/or firmware), and the preferred vehicle may vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, when referred to herein, the terms "station" and its abbreviation "STA", "user equipment" and its abbreviation "UE" may mean (i) a wireless transmit and/or receive unit (WTRU), such as described infra; (ii) any of a number of embodiments of a WTRU, such as described infra; (iii) a wireless-capable and/or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU, such as described infra; (iii) a wireless-capable and/or wired-capable device configured with less than all structures and functionality of a WTRU, such as described infra; or (iv) the like. Details of an example WTRU, which may be representative of any UE recited herein, are provided below with respect to <FIG>.

In certain representative embodiments, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and/or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality.

A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, Mobility Management Entity (MME) or Evolved Packet Core (EPC), or any host computer. The WTRU may be used m conjunction with modules, implemented in hardware and/or software including a Software Defined Radio (SDR), and other components such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a Near Field Communication (NFC) Module, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

Although the invention has been described in terms of communication systems, it is contemplated that the systems may be implemented in software on microprocessors/general purpose computers (not shown). In certain embodiments, one or more of the functions of the various components may be implemented in software that controls a general-purpose computer.

Throughout the disclosure, one of skill understands that certain representative embodiments may be used in the alternative or in combination with other representative embodiments.

Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, a read only memory (ROM), random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WRTU, UE, terminal, base station, RNC, or any host computer.

One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits.

The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory ("RAM")) or non-volatile ("e.g., Read-Only Memory ("ROM")) mass storage system readable by the CPU.

Claim 1:
A method, implemented by a wireless transmit/receive unit, WTRU, configured to manage a plurality of downlink, DL, bandwidth parts, BWPs, including an initial/default DL BWP, the method comprising:
receiving information related to a first channel occupancy time, COT;
selecting one or more active DL BWPs for the WTRU among the plurality of DL BWPs for the first COT based on the received information;
receiving information indicating an inactivity timer applicable for the one or more active DL BWPs;
starting the inactivity timer when the first COT begins;
receiving first downlink control information, DCI, on the one or more active DL BWPs during the first COT;
pausing the inactivity timer when the first COT ends;
starting the inactivity timer when a second COT begins;
deactivating the one or more active DL BWPs and activating the default BWP based on the inactivity timer expiring during the second COT; and
after activating the default BWP, receiving second DCI on the default BWP during a third COT,
wherein the second COT is later than the first COT, and the third COT is later than the second COT.