Patent Description:
<CIT> describes a method for uplink transmission performed by a UE. The method includes receiving a first configured grant configuration that allocates a first PUSCH duration; receiving a second configured grant configuration that allocates a second PUSCH duration, wherein the second PUSCH duration overlaps with the first PUSCH duration; obtaining a first HARQ process ID for the first PUSCH duration, then determining whether a first configured grant timer associated with the first HARQ process ID is running; obtaining a second HARQ process ID for the second PUSCH duration, then determining whether a second configured grant timer associated with the second HARQ process ID is running; and selecting one of the first PUSCH duration and the second PUSCH duration for an uplink transmission based on whether the first configured grant timer is running and whether the second configured grant timer is running.

Third Generation Partnership Project (3GPP) new radio (NR) includes ultra-reliable low latency communication (URLLC). Enhancements for URLLC and Industrial Internet of things (IIoT) were introduced in NR Release <NUM> (Rel-<NUM>). At the same time, NR was enhanced to operate in unlicensed/shared spectrum. Ongoing 3GPP discussions include harmonizing the operation of URLLC in unlicensed spectrum.

Uplink (UL) traffic can be scheduled with dynamic UL grants or configured UL grants. For dynamic grants, the gNB provides an UL grant to the user equipment (UE) for each UL transmission. Configured grants are pre-allocated, i.e., provided once to the UE. Thereafter, the configured UL grant is valid for UL transmissions
according to a configured periodicity. The UE does not need to transmit padding on the UL resources if no UL data is available for transmission. Thus, the UE may skip an UL transmission on such grants. Multiple parallel configured grant configurations (e.g., with different periodicity/allocation sizes) can be configured for the UE. Each configured grant configuration can be configured with nrofHARQ-Processes and harq-ProcID-Offset so that the UE can select a HARQ process ID within [harq-procID-offset,. , (harq-procID-offset + nrofHARQ-Processes - <NUM>).

A typical NR-Internet of Things (NR-IIoT) device may handle communication for multiple service types such as, for example, multiple periodic URLLC type robot control messages (also referred to as time sensitive network (TSN)-like traffic), URLLC type of occasional alarm signals (for which periodic resources would need to be configured or relying on UE to send scheduling request for each occasional alarm message), occasional sensor data transmission (can be time-critical or non-time-critical), other mobile broadband (Enhanced Mobile Broad Band (eMBB)/Mobile Broadband (MBB)) best-effort type traffic such as occasional video transmissions or software updates. This may lead to a traffic mix to be multiplexed by the UE for UL transmissions, i.e., on medium access control (MAC) multiple logical channels with different priorities would need to be configured. In such a traffic mix scenario, it is crucial to treat URLLC-type of traffic with high priority, while still maintaining a high efficiency/capacity to also serve other traffic types. Traffic of different logical channels (LCHs) can be mapped to different configured grant configurations.

Rel-<NUM> includes intra-UE multiplexing/prioritization (lch-basedPrioritization). For UL, when multiple UL grants overlap (e.g., a configured grant and dynamic grant or multiple configured grants), the MAC layer performs logical channel (LCH) and grants prioritization, where the general intention is that the grant on which the highest priority data allowed/transmitted is chosen. Data to be transmitted on the de-prioritized grant is to be transmitted at the next configured grant occasion, which is referred to as autonomousTx.

For unlicensed spectrum access, a separate mechanism for autonomous retransmissions on configured grants was introduced. A hybrid automatic repeat request (HARQ) process, for which an initial transmission could not take place because of listen before talk (LBT) failure, is considered a pending HARQ process. At each transmission on a HARQ process using a configured grant, the UE shall start a CG Retransmission Timer (CGRT) and if the reception of the HARQ process was not positively acknowledged at the expiry of the timer, the HARQ process is autonomously retransmitted. Whenever there is a pending HARQ process, it is similarly autonomously retransmitted at the next configured grant occasion. The UE chooses the next HARQ process for transmission itself, and it is mandated that the UE should prioritize retransmissions before transmissions of new data.

There currently exist certain challenges. For example, it is unclear how the UE is to prioritize between retransmission and transmission HARQ processes when they are shared between different configured grant configurations and how to apply logical channel prioritization.

The invention is defined by a method according to claim <NUM> and a wireless device according to claim <NUM>. Further details are defined by dependent claims <NUM>-<NUM> and <NUM>-<NUM>.

Although particular problems and solutions may be described using NR terminology, it should be understood that the same solutions apply to LTE and other wireless networks as well, where applicable.

All references to alan/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise.

As used herein, the terms "operating in unlicensed spectrum" and "operating in shared spectrum" are used interchangeably. Also, it is assumed that the cg-RetransmissionTimer is configured to support the operation in shared spectrum. For the embodiments described herein, for each configured grant configuration, retransmission is prioritized over initial transmission.

As used herein, the terms "HARQ process" and "HARQ process ID" are used interchangeably.

Considering a configuration where a pool of HARQ processes is shared among multiple configured grant configurations (which is a baseline agreement in ongoing 3GPP discussions), a E) may handle prioritization of transmissions as discussed below. The current MAC specification specifies that the UE implementation can select a HARQ process ID for transmission and retransmission is prioritized over initial transmission:
For configured UL grants configured with cg-RetransmissionTimer, the UE implementation selects an HARQ Process ID among the HARQ process IDs available for the configured grant configuration. The UE shall prioritize retransmissions before initial transmissions.

A problem may arise if the same HARQ process is chosen for two overlapping configured grants, because the UE implementation can select the HARQ Process ID on its own.

In some embodiments, the UE implementation avoids selecting the same HARQ process ID for overlapping configured grants. The UE chooses different HARQ processes for the overlapping configured grants, whenever possible.

According to certain embodiments, a method provided to enable the UE to efficiently prioritize data transmissions with different logical channel priorities when such transmissions are based on different configured grant configurations. Certain embodiments also relate to autonomous retransmissions resulting from LBT failures when operating in unlicensed spectrum.

For example, in particular embodiments, when prioritizing transmissions on overlapping configured grant resources for which HARQ processes are shared, the UE does not select the same HARQ process for overlapping configured grants. When there is only one shared HARQ process for retransmission in one configured grant, instead of choosing to use the HARQ process for new transmission in the overlapping configured grant, retransmission is prioritized over the new transmission. As a result, LCH-based prioritization is never applied for the same HARQ process.

In some embodiments, the UE prioritizes among retransmission and transmissions according to the LCH priority of the data. This applies for shared HARQ processes when all are used for ongoing retransmissions. When all HARQ processes are in use for retransmission, then some embodiments include flushing a HARQ process with lower priority retransmission data and using it for a new transmission of higher priority data. The step of HARQ flushing includes stopping the corresponding configured grant timer and configured grant retransmission timer so that the HARQ transmission is handled as a regular new transmission.

In one example, among the HARQ process identifiers (IDs) for initial transmissions, the UE prioritizes the non-overlapping HARQ process ID pools. On the other hand, among the HARQ process IDs for retransmissions, the UE prioritizes the overlapping HARQ process ID pools (if it can be chosen). The principle is that the UE avoids choosing the HARQ processes for a configured grant that might be chosen by another configured grant. If there is a HARQ process in this overlapping range that requires a retransmission, this should be picked first so that the data is transmitted and the HARQ process can be re-used again. If there is no such HARQ process for retransmission, the UE should choose a HARQ process ID from the non-overlapping pool.

<FIG> illustrates an example method <NUM> demonstrating how a UE chooses a HARQ process ID to transmit, according to certain embodiments. At step <NUM>, the UE determines whether there is any HARQ process for retransmission. If so, the UE then determines at step <NUM> whether there is more than one HARQ process for retransmission. If there is more than one HARQ process for retransmission, the UE picks one HARQ process from overlapping pools, at step <NUM>. Otherwise, the UE picks the one HARQ process, at step <NUM>. After step <NUM> or step <NUM>, the UE transmits data on the chosen HARQ process ID, at step <NUM>.

However, returning to step <NUM>, if the UE determines that there are no HARQ process IDs for retransmission, then the method proceeds to step <NUM>, and the UE picks a process ID from non-overlapping pools. The UE then transmits the data on the chosen HARQ process ID, at step <NUM>.

<FIG> illustrates a more detailed example <NUM> of overlapping HARQ process pools, according to a particular embodiment. Suppose that the CG1 is configured with a HARQ process pool, numbered from N_11 to N_12 and CG2 is configured with a HARQ process pool, numbered from N_21 to N_22. There is an overlap ifN_12 >= N_21, as shown in <FIG>.

The UE implementation chooses HARQ process between N_21 and N_12 if there is a retransmission among any HARQ process in this range (even though there can be other retransmission grants in other ranges). Otherwise, UE chooses the range N_11 to N_21 for CG1 and N_12 to N_22 for CG2. This improves the situation for subsequent prioritization decisions between configured grants. For example, in the non-overlapping HARQ processes, it is more likely that there are no ongoing retransmission that potentially block those HARQ IDs to be used for new transmissions (of higher priority data).

The method described above with regard to <FIG> is a simplified example in that the UE can always choose one in the non-overlapping or overlapping pool. In a follow-up example, for CG1, if there is no HARQ process for retransmission and it is not possible to choose a HARQ process ID from non-overlapping pools, the UE must choose a HARQ process ID in the overlapping pool. The UE implementation, for CG2, should avoid picking the same HARQ process ID within the overlapping pool, e.g., by choosing another HARQ process ID for retransmission in the overlapping pool if there are more than one in the overlapping pool or choosing another HARQ process ID for retransmission in the non-overlapping pool. The basic principle is the same: the UE avoids picking the same HARQ process ID for overlapping configured grants, while keeping the HARQ process ID in the overlapped HARQ process ID pool free from initial transmission (i.e., retransmission in the overlapped HARQ process ID pool is prioritized).

The examples above are simply one UE implementation example demonstrating how a UE may avoid using the same HARQ process for two overlapping configured grant resources. This can be implemented in the specification by one normative text as follows. For configured UL grants configured with cg-RetransmissionTimer, the UE implementation selects a HARQ Process ID among the HARQ process IDs available for the configured grant configuration. The UE shall prioritize retransmissions before initial transmissions. The UE shall toggle the new data indication (NDI) in the CG-UCI for new transmissions and not toggle the NDI in the CG-UCI in retransmissions. If the MAC entity is configured with lch-basedPrioritization, the UE implementation shall avoid selecting the same HARQ process ID for overlapping configured grants.

There may be cases in which a UE cannot avoid choosing the same HARQ process for the two overlapping configured grants. For example, all the HARQ processes between N_11 and N_21 in CG1 have their CG-RetransmissionTimer and CG-TransmissionTimer running and CG1 can only choose a HARQ process ID in the pool between N_21 and N_12 (with a size of one). CG2, on the other hand, has this only one HARQ process for retransmission. In this case, the retransmission is prioritized over initial transmission. This follows the principle in NR-U. This can be implemented in the specification by one normative text as follows.

For configured UL grants configured with cg-RetransmissionTimer, the UE implementation selects a HARQ Process ID among the HARQ process IDs available for the configured grant configuration, in a particular embodiment. The UE shall prioritize retransmissions before initial transmissions. The UE shall toggle the NDI in the CG-UCI for new transmissions and not toggle the NDI in the CG-UCI in retransmissions. If the MAC entity is configured with Ich-basedPrioritization, the UE implementation shall avoid selecting the same HARQ process ID for overlapping configured grants. If only the same HARQ process ID for overlapping configured grants can be chosen, the UE shall keep the grant for retransmission and discard the grant for initial transmission.

If both configured grants have the same transport block size (TBS) allocation, both grants would be chosen for retransmission, but because the retransmission data is the same (hence the priority is the same), the UE chooses by its implementation which grant to use (free choice). If configured grants have different TBS allocation, one configured grant cannot choose this for retransmission and can only accommodate an initial transmission. Thus, only one grant is chosen. In both cases, the end result is that there are not two overlapping grants with the same HARQ process to perform LCH-based grant prioritization. This results from the embodiment described above where, in the case of limited HARQ processes available to choose from, for HARQ processes that are usable in both configured grants, retransmission is chosen instead of transmission of new data. The network can ensure that new transmissions (of higher priority data) are chosen by configuring an appropriate number of non-shared HARQ processes for each configured grant configuration.

In a second group of embodiments, the LCH-based decision is considered more important than the retransmission decision because, following the principle that different priority data is transmitted on different configured grants, particular embodiments prioritize the higher priority data and its corresponding grant.

According to some embodiments, this only applies to shared HARQ processes of the overlapping configured grants and when no other HARQ processes are available for new transmissions. Within each configured grant's HARQ process pool, the UE may prioritize retransmissions before new transmissions, which may result in choosing the same HARQ process ID for both configured grants. Thereafter, LCH-based prioritization is applied to prioritize among configured grants for this same HARQ process according to the LCH-based priority of the data to be transmitted or retransmitted. When new transmission is prioritized over retransmission, the retransmission HARQ process needs to be flushed/reset, which according to one embodiment involves stopping of configured grant timer and cg-RetransmissionTimer, to ensure the correct handling of the new data, i.e. giving the new data the correct amount of time for potential later retransmission (after cgRetransmissionTimer expired until configured grant timer expired).

In some embodiments, when all HARQ processes are undergoing retransmissions for overlapping grants, the UE chooses the configured grant with the retransmission that includes the highest priority LCH data, i.e. applies LCH-based prioritization among the retransmissions. In this case, the priority of an UL grant for which the retransmission data is not associated with any logical channel (e.g., the retransmission of a MAC CE) is lower than the priority of an UL grant for which the retransmission data is associated with any logical channel.

In some embodiments, to reduce the case in which the same HARQ process is chosen for the two configured grants configurations (one for retransmission and one for initial transmission) and leads to a flush of the HARQ buffer of the grant for retransmission, the UE shall avoid selecting the same HARQ process ID for overlapping grants.

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

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

In such a scenario, each unique NodeB and RNC pair may in some instances be considered a single separate network node.

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

<FIG> illustrates an example wireless device <NUM>, according to certain embodiments. As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (IoT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated in <FIG>, wireless device <NUM> includes antenna <NUM>, interface <NUM>, processing circuitry <NUM>, device readable medium <NUM>, user interface equipment <NUM>, auxiliary equipment <NUM>, power source <NUM> and power circuitry <NUM>.

As illustrated in <FIG>, interface <NUM> comprises radio front end circuitry <NUM> and antenna <NUM>.

<FIG> illustrates an example telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments.

OTT connection <NUM> may be transparent in the sense that the participating communication devices through which OTT connection <NUM> passes are unaware of routing of UL and downlink communications. Similarly, base station <NUM> need not be aware of the future routing of an outgoing UL communication originating from the UE <NUM> towards the host computer <NUM>.

Wireless connection <NUM> between UE <NUM> and base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE <NUM> using OTT connection <NUM>, in which wireless connection <NUM> forms the last segment.

<FIG> illustrates an example method <NUM> performed by a wireless device <NUM>, according to certain embodiments. In the illustrated method, the wireless device <NUM> is configured with a first configured grant (CG1) associated with a first HARQ pool and a second configured grant (CG2) associated with a second HARQ pool. The first HARQ pool at least partially overlaps with the second HARQ pool, and the second configured grant partially overlaps with the first configured grant.

At step <NUM>, the wireless device <NUM> selects, a first HARQ process from the first HARQ pool for the first configured grant. At step <NUM>, the UE selects a second HARQ process from the second HARQ pool for the second configured grant. The first HARQ process selected for the first configured grant is different than the second HARQ process selected for the second configured grant. The wireless device <NUM> performs UL transmission or retransmission for the first configured grant or the second configured grant, at step <NUM>.

In a particular embodiment, when selecting the first HARQ process for the first configured grant and the second HARQ process for the second configured grant, the wireless device <NUM> determines whether there is a retransmission among any of the HARQ processes in an overlapping portion of the first and second HARQ pools. When there is the retransmission among any of the HARQ processes in the overlapping portion of the first and second HARQ pools, a selected HARQ process is for the retransmission and is from the overlapping portion of the first and second HARQ pools. Conversely, when there is no retransmission among any of the HARQ processes in the overlapping portion of the first and second HARQ pools, the first HARQ process for the first configured grant and the second HARQ process for the second configured grant are from the non-overlapping portion of the first and second HARQ pools.

In a particular embodiment, when determining there is a retransmission among all of the HARQ processes in the overlapping portion of the first and second HARQ pools, the wireless device <NUM> flushes a HARQ process with a lower priority retransmission data and uses the HARQ process for a new transmission of higher priority data.

In a particular embodiment, the first HARQ process is for retransmission of data according to the first configured grant, and the second HARQ process is for initial transmission of data according to the second configured grant. In this scenario, the wireless device <NUM> prioritizes the retransmission of data according to the first configured grant over the initial transmission of data according to the second configured grant, in a particular embodiment.

In a particular embodiment, the first HARQ process is for transmission or retransmission of high priority logical channel data according to the first configured grant, and the second HARQ process is for transmission or retransmission of low priority logical channel data according to the second configured grant. In this scenario, the wireless device <NUM> prioritizes the transmission or retransmission of the high priority logical channel data according to the first configured grant over the transmission or retransmission of low priority logical channel data according to the second configured grant, in a particular embodiment.

In a particular embodiment, when selecting the first HARQ process, the wireless device <NUM> selects a first HARQ process identifier. Likewise, when selecting the second HARQ process, the wireless device <NUM> selects a second HARQ process identifier.

Claim 1:
A method performed by a wireless device (<NUM>), wherein the wireless device is configured with a first configured grant associated with a first hybrid automatic repeat request, HARQ, pool and a second configured grant associated with a second HARQ pool, and wherein the first HARQ pool at least partially overlaps with the second HARQ pool, and wherein the second configured grant partially overlaps with the first configured grant, the method comprising:
for the first configured grant, selecting (<NUM>) a first HARQ process from the first HARQ pool,
for the second configured grant, selecting (<NUM>) a second HARQ process from the second HARQ pool, wherein the first HARQ process selected for the first configured grant is different than the second HARQ process selected for the second configured grant; and
performing (<NUM>) UL transmission or retransmission for the first configured grant or the second configured grant; wherein when selecting the first HARQ process for the first configured grant and the second HARQ process for the second configured grant, the method further comprises:
determining (<NUM>) whether there is a retransmission among any of the HARQ processes in an overlapping portion of the first and second HARQ pools,
wherein, when there is the retransmission (<NUM>) among any of the HARQ processes in the overlapping portion of the first and second HARQ pools, the first or second HARQ process is for the retransmission and is from the overlapping portion of the first and second HARQ pools; and
wherein when there is no retransmission (<NUM>) among any of the HARQ processes in the overlapping portion of the first and second HARQ pools, the first HARQ process for the first configured grant and the second HARQ process for the second configured grant are from the non-overlapping portion of the first and second HARQ pools.