Patent Description:
The present disclosure relates to communications networks and, more specifically, to Hybrid Acknowledgement Repeat Request (HARQ) for communication networks.

There is an ongoing resurgence of satellite communications. Several plans for satellite networks have been announced in the past few years. The target services vary, from backhaul and fixed wireless, to transportation, to outdoor mobile, to Internet of Things (IoT). Satellite networks could complement mobile networks on the ground by providing connectivity to underserved areas and multicast/broadcast services.

To benefit from the strong mobile ecosystem and economy of scale, adapting the terrestrial wireless access technologies including Long Term Evolution (LTE) and New Radio (NR) for satellite networks is drawing significant interest. For example, Third Generation Partnership Project (3GPP) completed an initial study in Release <NUM> on adapting NR to support non-terrestrial networks (mainly satellite networks) (see TR <NUM> V15. <NUM>, Study on New Radio (NR) to support non-terrestrial networks). This initial study focused on the channel model for the non-terrestrial networks, defining deployment scenarios, and identifying the key potential impacts. 3GPP is conducting a follow-up study item in Release <NUM> on solutions evaluation for NR to support non-terrestrial networks (see RP-<NUM>, Study on solutions evaluation for NR to support non-terrestrial Network).

A satellite radio access network usually includes the following components:.

The link from gateway to terminal is often called forward link, and the link from terminal to gateway is often called return link. Depending on the functionality of the satellite in the system, we can consider two transponder options.

Depending on the orbit altitude, a satellite may be categorized as Low Earth Orbiting (LEO), Medium Earth Orbiting (MEO), or Geostationary (GEO) satellite.

A communication satellite typically generates several beams over a given area. The footprint of a beam is usually in an elliptic shape, which has been traditionally considered as a cell. The footprint of a beam is also often referred to as a spotbeam. The footprint of a beam may move over the earth surface with the satellite movement or may be earth fixed with some beam pointing mechanism used by the satellite to compensate for its motion. The size of a spotbeam depends on the system design, which may range from tens of kilometers to a few thousands of kilometers.

<FIG> shows an example architecture of a satellite network with bent pipe transponders.

The two main physical phenomena that affect satellite communications system design are the long propagation delay and Doppler effects. The Doppler effects are especially pronounced for LEO satellites.

Propagation delay is a main physical phenomenon in a satellite communication system that makes the design different from that of a terrestrial mobile system. For a bent pipe satellite network, the following delays are relevant.

Note that there may be additional delay between the ground BS antenna and BS, which may or may not be collocated. This delay depends on deployment. If the delay cannot be ignored, it should be taken into account in the communications system design.

The propagation delay depends on the length of the signal path, which further depends on the elevation angles of the satellite seen by the BS and UE on the ground. The minimum elevation angle is typically more than <NUM>° for UE and more than <NUM>° for BS on the ground. These values will be assumed in the delay analysis below.

The following Tables <NUM> and <NUM> are taken from 3GPP TR <NUM> V15. <NUM>, Study on New Radio (NR) to support non-terrestrial networks. We can see that the round-trip delay is much larger in satellite systems. For example, it is about <NUM> for a GEO satellite system. In contrast, the round-trip time is normally no more than <NUM> for typical terrestrial cellular networks.

Generally, within spot beam covering one cell, the delay can be divided into a common delay component and a differential delay component. The common delay is the same for all UEs in the cell and is determined with respect to a reference point in the spot beam. In contrast, the differential delay is different for different UEs which depends on the propagation delay between the reference point and the point at which a given UE is positioned within the spot beam.

The differential delay is mainly due to the different path lengths of the service links, since the feeder link is normally the same for terminals in the same spotbeam. Further, the differential delay is mainly determined by the size of the spotbeam. It may range from sub-millisecond (for spotbeam on the order of tens of kilometres) to tens of millisecond (for spotbeam on the order of thousands of kilometres).

In RAN#<NUM>, a new SI "Solutions for NR to support Non Terrestrial Network" was agreed (see RP-<NUM>, Study on solutions evaluation for NR to support non-terrestrial Network).

It is a continuation of a preceding SI "NR to support Non-Terrestrial Networks" (RP-<NUM>), where the objective was to study the channel model for the non-terrestrial networks, to define deployment scenarios, parameters and identify the key potential impacts on NR. The results are reflected in TR <NUM>, V15.

The objectives of the current SI are to evaluate solutions for the identified key impacts from the preceding SI and to study impact on Radio Access Network (RAN) protocols/architecture. The objectives for layer <NUM> and above are:.

Note: This new study item does not address regulatory issues:.

The coverage pattern of Non-Terrestrial Network (NTN) is described in TR <NUM> V15. <NUM> in Section <NUM> as follows:.

Satellite or aerial vehicles typically generate several beams over a given area. The foot print of the beams are typically elliptic shape.

The beam footprint may be moving over the earth with the satellite or the aerial vehicle motion on its orbit. Alternatively, the beam foot print may be earth fixed, in such case some beam pointing mechanisms (mechanical or electronic steering feature) will compensate for the satellite or the aerial vehicle motion.

Typical beam patterns of various NTN access networks are depicted in <FIG>.

The TR of the ongoing SI, TR <NUM> V0. <NUM>, describes scenarios for the NTN work as follows:.

Non-Terrestrial Network typically features the following elements:.

Four scenarios are considered as depicted in Table <NUM>-<NUM> and are detailed in Table <NUM>-<NUM>.

The numbers in the table above marked with (*) corresponds to an altitude of <NUM>.

For scenario D, which is LEO with regenerative payload, both earth-fixed and earth moving beams have been listed. So, when we factor in the fixed/non-fixed beams, we have an additional scenario. The complete list of <NUM> scenarios in <NUM> is then:.

There currently exist certain challenge(s).

Existing HARQ procedures at the PHY/MAC layer have been designed for terrestrial networks where the round-trip propagation delay is restricted to be within the cyclic prefix (CP) duration. Thus, existing HARQ procedures in LTE/NR are not well suited for satellite-based networks.

Document "<NPL> may be construed to disclose an evaluation on NR MAC architecture and MAC modelling in presence of multiple numerologies and/or TTI durations. The following proposals and observations were made. Proposal <NUM>: A single DL-SCH can support transmissions using different numerologies and/or TTI duration. Proposal <NUM>: A single UL-SCH can support transmissions using different numerologies and/or TTI duration. Observation <NUM>: RRC can configure a DRB with a parameter that corresponds to the mapping between data available for transmission for the corresponding LCH and a specific grant as indicated by the PHY layer. Proposal <NUM>: A UE MAC entity can support the configured mapping between a LCH and a grant associated to a specific TTI duration without knowledge of the applicable numerology and/or TTI duration. Proposal <NUM>: MAC support variable timing for transmission of DL HARQ feedback. The UE MAC entity adjusts DRX timers according to the HARQ RTT Timer signalled for the given TTI duration. Proposal <NUM>: Capture the attached TP part of the NR MAC TS.

Document "<NPL> may be construed to disclose an evaluation on delivery procedures of other SI. The following proposals and observations were made. Observation <NUM>: Alternative <NUM>-<NUM> (One HARQ process for the entire/multiple aggregated component carriers, with different redundancy version) enables efficient HARQ operation as a single HARQ is performed across the involved component carriers. Hence, it can reduce the HARQ handling latency and naturally support HARQ soft combination across component carriers compared to above two approaches. And the method is similar as TTI bundling in LTE, which is just a kind of bundling in frequency domain. Observation2: RANI need to be involved for the study of the MAC structure which allows one HARQ process configured across multiple aggregated component carriers. Proposal <NUM>: It is proposed that the MAC structure allows one HARQ process configured across multiple aggregated component carriers, if it is desirable, with different redundancy versions during data duplication operation for URLLC services.

Document "<NPL> may be construed to disclose an evaluation on optional impacts of intra-UE prioritization/multiplexing on RANI (prioritization between physical channels) and RAN2 (prioritization between grants and prioritization between logical channels). The following proposals were made. Proposal <NUM>: RAN2 study solution on UL grant prioritization and LCP for intra-UE prioritization. Proposal <NUM>: RANI study solution on prioritization between physical channels, including data and control channel, for UL and DL.

Document "<NPL> may be construed to disclose an evaluation on basic design issues that should be considered if using repetition or TTI length switching for 2msec TTI range extension. As part of a standardisation phase, a number of design decisions would need to be taken: Repetition vs TTI length extension; TTI/repetition length; channel structure and multiplexing of E-DPCCH/E-DPDCH - it would be preferable to allow for decoding of E-DPCCH in the first 2msec TTI. This can be achieved if E-DPCCH is only transmitted in the 2msec TTI. It is then TBD whether any E-DPDCH is also transmitted in that TTI, use of TTIs for repetition/reservation of some TTIs for other traffic - reservation of some TTIs may allow more options for transmitting SRBs etc.; system operation: Node B or UE decides to do repetition on a TTI by TTI basis - the UE has more information on its UPH and must inform non serving Node Bs anyhow if it is doing repetition; UE deciding is preferable; application of retransmissions and ACK/NACK signalling - no retransmissions of repetitions; signalling of the use of repetition by the UE to the Node B(s); and E-TFC selection.

In this disclosure, systems and methods for mapping data on specific HARQ process ID to account for large propagation delays and still offer reliable communication are disclosed.

According to the invention, there are provided methods, a user equipment, a base station and a computer-readable medium according to the independent claims. Further developments are set forth in the dependent claims.

Additional information may also be found in the document(s) provided in the Appendix.

Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (<NUM>) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a highpower or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

Note that, in the description herein, reference may be made to the term "cell;" however, particularly with respect to <NUM> NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

In the following discussion, Hybrid Automatic Repeat Request (HARQ) protocol refers to the HARQ procedure at the Physical (PHY) / Medium Access Control (MAC) layer.

Existing HARQ procedures at the PHY/MAC layer have been designed for terrestrial networks where the round-trip propagation delay is restricted to be within the cyclic prefix (CP) duration. With HARQ protocol, a transmitter needs to wait for the feedback from the receiver before sending new data. In case of a negative acknowledgement (NACK), the transmitter may need to resend the data packet. Otherwise, it may send new data. This stop-and-wait (SAW) procedure introduces inherent latency to the communication protocol, which may reduce the link throughput. To alleviate this issue, existing HARQ procedure allows activating multiple HARQ processes at the transmitter. That is, the transmitter may initiate multiple transmissions in parallel without having to wait for a HARQ completion. For example, with <NUM> (<NUM>) HARQ processes in NR (LTE) DL, the gNB (eNB) may initiate up to <NUM> (<NUM>) new data transmissions without waiting for an ACK for the first packet transmission. Note that there are sufficient number of HARQ processes for terrestrial networks where the propagation delay is typically less than <NUM>.

<FIG> shows the various delays associated with the HARQ procedure:.

Some issues with existing HARQ protocol amid large propagation delays are identified below:
The existing HARQ mechanism may not be feasible when the propagation delay is much larger than that supported by the allowed number of HARQ processes. For example, consider the scenario where LTE DL is to be adopted for satellite communications. For the GEO case, the RTT propagation delay can be around <NUM>. With <NUM> HARQ processes, the eNB needs to wait for around <NUM> before sending new data. This translates to benefitting from only a meager fraction (<NUM>/<NUM>) of the available peak throughput. Therefore, without a sufficient number of HARQ processes, the sheer magnitude of the propagation delay may render closed-loop HARQ communication impractical.

The number of HARQ processes supported by the existing HARQ protocol are not sufficient to absorb the potentially large propagation delays in non-terrestrial networks. For example, Table <NUM> shows that a substantial increase in the existing number of HARQ processes (Note: Rel-<NUM> NR supports a maximum of <NUM> HARQ processes in UL/DL per serving cell. LTE supports <NUM> for UL/DL per serving cell) is required for operating HARQ amid large propagation delays. Unfortunately, it is challenging to support that many HARQ processes specially at UE side, due to e.g. the following reasons.

It requires large memory at both the transmitter and receiver.

It may require reducing the HARQ buffer size (and thus the maximum supported TBS).

A large number of HARQ buffers implies a large number of HARQ receivers.

It may increase the signaling overhead for HARQ ID.

In short, the existing (PHY/MAC) HARQ mechanism is ill-suited to non-terrestrial networks with large propagation delays. Moreover, there is no existing signaling mechanism for disabling HARQ at the PHY/MAC layers. Therefore, there is a need to develop new signaling procedures for adapting HARQ to non-terrestrial networks.

For example, in non-terrestrial networks where the propagation delay is large, activating the HARQ feedback loop may considerably reduce the throughput due to the inherent stop-and-wait property of the HARQ protocol. With the ability to deactivate HARQ, the eNB/gNB/UE need not wait for the HARQ feedback or retransmissions before transmitting new data. Moreover, it helps saves the time/frequency/energy/computational resources required for HARQ feedback transmission.

In certain scenarios such as in poor channel conditions, it may also be desirable to operate with HARQ enabled so as to avoid aggressive retransmissions and increased latency at the higher layers.

The above enabling/disabling of feedback for certain HARQ processes has earlier been proposed to allow the network to configure the UE to disable parts of the HARQ procedure to mitigate some of the negative impact inflicted by the propagation delay of a non-terrestrial network.

If the HARQ procedure is turned off or altered, there is a risk that the reliability is reduced due to the non-exiting feedback. The reliability could then be increased by using more robust modulation and coding schemes but only to a certain extent. If transport blocks with errors are passed up to higher layers, e.g. RLC, PDCP, TCP, retransmission may occur which will again increase the delay mitigating some of the effect of disabling the HARQ procedure.

To increase the reliability, i.e. reduce the block error rate, BLER, for a non-terrestrial network with HARQ feedback disabled for some specific HARQ process IDs, it has also been proposed to allow bundling of TBs on a per HARQ process ID level. This would allow TBs sent on a specific HARQ process ID to be retransmitted a configurable number of times to reach the BLER targeted for the communication.

In current NR and LTE specifications, the network is in control of what LCHs that shall be served in DL for a given TB. it is up the network implementation to concatenate data so that bitrates for the different LCH are fulfilled. A TB will then be sent using the next in order and available HARQ process ID. In the uplink, there is Logical Channel Prioritization procedure, configured by RRC, that controls the amount of data that will be sent from each of the available LCH until the size of the TB meet the allocated size indicated in the grant. The TB will then be sent using the next in order and available HARQ process ID.

Given a non-terrestrial network with the new above proposed solutions for disabling and enabling HARQ feedback on a per HARQ processes level as well as to allow bundling on a per HARQ process level implemented, there is currently no means to map certain data/signaling to a certain HARQ process ID, i.e. without a well-defined mapping of what data that is sent on what HARQ process ID, the use of HARQ feedback disabling or HARQ process ID bundling will be of little use.

In this disclosure, systems and methods for mapping data on specific HARQ process ID to account for large propagation delays and still offer reliable communication are provided.

Embodiments described herein provide mapping of data to specific HARQ process IDs.

Certain embodiments may provide none, one or more of the following technical advantage(s). Embodiments of the proposed solution introduce methods for to map specific data to specific HARQ processes to allow some data to be sent with the HARQ procedure enabled and for other data, disabled.

Referring back to <FIG>, one example of a satellite-based radio access network <NUM> in which embodiments of the present disclosure may be implemented is illustrated. In some embodiments, the satellite-based radio access network <NUM> is a radio access network for a cellular communications network such as, e.g., a LTE or NR network.

As illustrated, the satellite-based radio access network <NUM> includes, in this example, a base station <NUM> that connects the satellite-based radio access network <NUM> to core network (not shown). In this example, the base station <NUM> is connected to a ground-based base station antenna <NUM> that is, in this example, remote from (i.e., not collocated with) the base station <NUM>. The satellite-based radio access network <NUM> also includes a satellite <NUM>, which is a space-borne platform, that provides a satellite-based access link to a User Equipment (UE) <NUM> located in a respective spotbeam, or cell, <NUM>.

The term "feeder link" refers to the link between the base station <NUM> (i.e., the base station antenna <NUM> in this example in which the base station <NUM> and the base station antenna <NUM> are not collocated) and the satellite <NUM>. The term "service link" refers to the link between the satellite <NUM> and the UE <NUM>. The link from the base station <NUM> to the UE <NUM> is often called the "forward link", and the link from UE <NUM> to base station <NUM> is often called the "return link" or "access link. " Depending on the functionality of the satellite <NUM> in the satellite-based radio access network <NUM>, two transponder options can be considered:.

Since there might be data and/or control signaling sent between the UE and the non-terrestrial network that requires higher reliability, it has been previously proposed to allow the network to disable HARQ feedback for certain HARQ processes only (see <CIT>).

With the above solution of disabling HARQ feedback for certain HARQ processes, there is a need to use different aggregation factors for different HARQ processes. For example, it may be desirable for a HARQ process with HARQ feedback disabled to be configured with a higher aggregation factor than a HARQ process with HARQ feedback enabled. Note that an aggregation factor is a number that represents the number of times that the transport block will be retransmitted within a bundle. Without the capability of controlling aggregation factors for different HARQ processes, a single aggregation factor has to be used for all the HARQ processes regardless whether the HARQ feedback is enabled/disabled for a particular HARQ process. If the aggregation factor is small or not configured (i.e., aggregation factor = <NUM>), a much larger proportion of Transport Block transmission errors (associated with HARQ process(es) without HARQ feedback) than what is designed in the specification needs to be recovered by higher layer retransmission techniques, such as RLC AM mode, PDCP, RRC or TCP. This results in a much higher latency and a reduced throughput. To avoid this, a large value needs to be configured for the aggregation factor, but this in turn makes the transmissions on the HARQ processes with HARQ feedback enabled spectrally inefficient and experience higher latency.

Several embodiments are described below. Embodiments <NUM> in particular, is aiming at addressing some of the challenges identified above, with respect to mapping data to HARQ processes. While described separately, these embodiments may be used in any desired combination.

In one embodiment, bundling of transport blocks (TBs) is enabled for a specific HARQ process (e.g., a HARQ process identified by a specific HARQ process ID). This is sometimes referred to herein as "HARQ process specific bundling". Bundling is available in NR for both uplink and downlink and for both dynamic and configured scheduling. In the existing NR specification, however, bundling can only be activated for all transmissions on all configured HARQ processes. That is, bundling cannot be activated for a specified subset of HARQ processes. Given the proposed ability to disable the HARQ feedback for one or more specific HARQ processes (see <CIT>), the reliability would decrease for all TBs sent using these HARQ processes if the aggregation factor is small or not configured. Since not all HARQ processes will have their feedback disabled, it will be useful to increase the reliability by allowing bundling for one or more specific HARQ process IDs (e.g., using HARQ process specific aggregation factor).

Example: HARQ Process ID = <NUM> has its HARQ feedback disabled but is at the same time configured for bundling. When this HARQ process is used for transmission of a TB, it is bundled and the receiver knows how to receive and process these TBs within the bundle. Note that the reception and processing of TBs within the bundle can be performed in any suitable manner such as, e.g., the conventional manner. In case the transmitter desires not using bundling, it may use a HARQ process ID not configured for bundling.

HARQ process specific bundling could be used for HARQ process having a specific HARQ process ID regardless of whether HARQ feedback is disabled or not for that HARQ process.

Which HARQ process to bundle in uplink or downlink can be indicated in any suitable manner such as e.g. indicated dynamically in the received DCI using a bit indication, indicated using a specific RNTI(s), indicated using a MAC CE, indicated semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like.

In some embodiments, the aggregation factor to be used for bundling (e.g., for HARQ-disabled transmission) is configured, e.g., semi-statically (e.g., via RRC signaling). Further, in some embodiments, bundling is enabled for all transmissions using a HARQ process(es) for which HARQ mechanism(s) are disabled. Some examples of how HARQ mechanisms can be disabled are described in see <CIT>.

In another embodiment, the New Data Indicator (NDI) field in the DCI scheduling a transmission for a specific HARQ process (e.g., indicated by a HARQ process ID) is used to indicate whether bundling is enabled for the HARQ process or not. When HARQ is disabled for certain HARQ process IDs using one or more of the mechanisms proposed in see <CIT>, the NDI fields for those HARQ processes may be redundant. The NDI fields for those HARQ processes can be repurposed, for example using new signaling (e.g., RRC signaling), to indicate whether or not bundling is activated for the respective HARQ processes.

<FIG> illustrates the operation of a base station <NUM> and a UE <NUM> in accordance with at least some aspects of Embodiment <NUM> described above. Optional steps are represented with dashed lines. As illustrated, the base station <NUM> optionally determines (e.g., decides) to enable bundling for a specific HARQ process(es) (step <NUM>). For example, the base station <NUM> may determine to enable bundling for a HARQ process(es) for which HARQ mechanism(s) have been disabled. Notably, the HARQ process(es) for which bundling is enabled is a subset of all configured HARQ processes. The base station <NUM> provides an indication to the UE <NUM> of the HARQ process(es) for which bundling is enabled (step <NUM>). This indication can be provided to the UE <NUM> in any suitable manner such as e.g. indicated dynamically in the received DCI using a bit indication, indicated using a specific RNTI(s), indicated using a MAC CE, indicated semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like. Optionally, in some embodiments, the base station <NUM> also provides, to the UE <NUM>, an indication of the number of bundles to use (step <NUM>).

At the UE <NUM>, the UE <NUM> receives the indication in step <NUM> and optionally the indication in step <NUM> and, based on the received indication(s), determines that bundling is enabled for the specific indicated HARQ process(es) (step <NUM>). The UE <NUM> and the base station <NUM> then perform DL/UL data transmission/reception associated with the indicated HAR process(es) with bundling enabled (step <NUM>).

In one embodiment, bundling of non-contiguous received/transmitted TBs is enabled for a specific HARQ process(es). If configured, this would allow the network or UE to send TBs with the same HARQ process ID not necessarily contiguously, i.e., non-contiguous bundling. This would allow the transmitter to spread transmissions to achieve time diversity and avoid temporary radio propagation obstacles such as fast fading and, if delay tolerable, even slow fading mechanisms.

The current NR specification states that if the UE is configured with aggregationFactor > <NUM> (i.e., bundling is enabled), the same symbol allocation is applied across the aggregationFactor consecutive slots, and the UE may expect that the TB is repeated within each symbol allocation among each of the aggregationFactor consecutive slots.

A non-contiguous bundling pattern (i.e., a pattern that defines the location of the bundled TBs, e.g., in time (and optionally frequency)) can be indicated to the UE in any suitable manner such as e.g., by RRC, DCI bitmap, etc. or by a number of retransmissions plus NDI.

Example: The bundling is configured with a period of X slots, and the same symbol allocation is applied every X-th slot. As a result, the total transmission duration of a bundle is X * aggregationFactor slots.

<FIG> illustrates the operation of a base station <NUM> and a UE <NUM> in accordance with at least some aspects of Embodiment <NUM> described above. Optional steps are represented with dashed lines. As illustrated, the base station <NUM> optionally determines (e.g., decides) to enable non-contiguous bundling for a specific HARQ process(es) (step <NUM>). For example, the base station <NUM> may determine to enable non-contiguous bundling for a HARQ process(es) for which HARQ mechanism(s) have been disabled. Notably, the HARQ process(es) for which non-contiguous bundling is enabled is a subset of all configured HARQ processes. The base station <NUM> provides an indication to the UE <NUM> of the HARQ process(es) for which bundling is enabled (step <NUM>). This indication can be provided to the UE <NUM> in any suitable manner such as e.g. indicated dynamically in the received DCI using a bit indication, indicated using a specific RNTI(s), indicated using a MAC CE, indicated semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like. Optionally, in some embodiments, the base station <NUM> also provides, to the UE <NUM>, an indication of the number of bundles to use and/or a non-contiguous bundling pattern(s) for the indicated HARQ process(es) (step <NUM>).

At the UE <NUM>, the UE <NUM> receives the indication in step <NUM> and optionally the indication in step <NUM> and, based on the received indication(s), determines that non-contiguous bundling is enabled for the specific indicated HARQ process(es) (step <NUM>). The UE <NUM> and the base station <NUM> then perform DL/UL data transmission/reception associated with the indicated HAR process(es) with non-contiguous bundling enabled (step <NUM>).

It should be noted that, in step <NUM>, the base station <NUM> may determine to configure a first HARQ process for contiguous bundling and second HARQ process for non-contiguous bundling. In this case, the base station <NUM> can, for example, indicate to the UE <NUM> in step <NUM> that bundling is enabled for both the first and second HARQ processes. Then, the base station <NUM> may provide a further indication to the UE <NUM> that the bundling for the second HARQ process is non-contiguous, e.g., by indicating a respective non-contiguous bundling pattern to the UE <NUM>, e.g., in step <NUM>. Then, in step <NUM>, contiguous bundling is used for the first HARQ process and non-contiguous bundling is used for the second HARQ process.

The current NR specification requires generating possibly different redundancy versions of the TB, and a version of the TB is transmitted at each transmission occasion from the total of aggregationFactor transmission occasions in a bundle. In one embodiment, instead, the codeword could be directly generated, rate matched, modulated and mapped to all the resource elements from the available symbols assigned to the TB.

Example: DCI indicates the assignment of Y symbols in a slot using Z resource blocks. Bundling is configured with a period of X slots, and the same symbol allocation is applied every X-th slot. So in total, there would be <NUM>*Z*Y* aggregationFactor resource elements minus not available resource elements (such as those used by reference signals). The codeword for the TB is generated, rate matched, and the corresponding bits are modulated and mapped to the available resource elements.

In one embodiment, a HARQ process timer for bundling of (non-) contiguous TBs is provided. Similar to bundling of X non-contiguous TBs for a certain HARQ process (e.g., identified by a certain HARQ process ID), the UE keeps monitoring for a specific HARQ process ID while the HARQ process timer is running. When the timer expires, the UE uses the received bundle of TBs, with possibly different redundancy versions, to decode the TB. The timer could be connected to each HARQ process, and the network (e.g. the base station <NUM>) should not reuse the same HARQ process ID until the timer has expired or if the NDI is toggled. If configured, it would allow the network to send a TB multiple times depending on the load. For times of low load, more redundancy could be achieved and at high load, less redundancy. This embodiment can be used regardless of whether HARQ feedback is turned on or off (i.e., regardless of whether HARQ mechanism(s) are deactivated for the respective HARQ process).

Example: If HARQ process ID <NUM>, <NUM> and <NUM> is configured for HARQ process ID bundling with a HARQ process timer set to X ms, the receiver would store all received TBs for a process ID, possibly with different redundancy version, until the timer expires. The received TBs would then be combined before decoding to reduce the probability of decoding error.

<FIG> illustrates the operation of a base station <NUM> and a UE <NUM> in accordance with at least some aspects of Embodiment <NUM> described above. Optional steps are represented with dashed lines. As illustrated, the base station <NUM> optionally determines (e.g., decides) to enable (non-contiguous) bundling for a specific HARQ process(es) (step <NUM>). For example, the base station <NUM> may determine to enable (non-contiguous) bundling for a HARQ process(es) for which HARQ mechanism(s) have been disabled. Notably, the HARQ process(es) for which (non-contiguous) bundling is enabled is a subset of all configured HARQ processes. The base station <NUM> provides an indication to the UE <NUM> of the HARQ process(es) for which bundling is enabled (step <NUM>). This indication can be provided to the UE <NUM> in any suitable manner such as e.g. indicated dynamically in the received DCI using a bit indication, indicated using a specific RNTI(s), indicated using a MAC CE, indicated semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like. Optionally, in some embodiments, the base station <NUM> also provides, to the UE <NUM>, an indication HARQ process timer value(s) for the HARQ process(es) for which bundling is enabled (step <NUM>). This indication may be provided to the UE <NUM> in any suitable manner such as, e.g., dynamically in the received DCI using a bit indication, using a specific RNTI(s), using a MAC CE, using semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like. Note that if bundling is enabled for two or more specific HARQ processes, a single HARQ process timer value may be indicated for all of these HARQ processes or separate HARQ process timer values may be indicated for the separate HARQ processes.

At the UE <NUM>, the UE <NUM> receives the indication in step <NUM> and optionally the indication in step <NUM> and, based on the received indication(s), determines that bundling is enabled for the specific indicated HARQ process(es) (step <NUM>). The UE <NUM> starts a HARQ process timer(s) for the indicated HARQ process(es), where the HARQ process timer(s) is set to a value(s) indicated by the base station <NUM> in step <NUM> or set to value(s) that are otherwise defined for configured. The UE <NUM> and the base station <NUM> then perform DUUL data transmission/reception associated with the indicated HAR process(es) with bundling enabled while the respective HARQ process timer(s) is running (step <NUM>).

Here, a number of example variations for how HARQ process specific bundling is indicated to the UE <NUM> are described.

In some embodiment, RRC is used to provide the indication to enable bundling for a specific HARQ process(es). Two examples of RRC configuration are as follows:.

In some other embodiments, a combination of RRC and MAC CE or a combination of RRC and DCI is used to configure bundling for a specific HARQ process(es).

In some other embodiments, RRC configures a set of bundling and HARQ on/off states for given HARQ process or common to all HARQ processes. MAC CE or DCI may then indicate which of the preconfigured states becomes active/deactive. Option <NUM> is that each HARQ process is configured with N possible states, where one state can mean bundling is assumed and no HARQ, or bundling is assumed and HARQ is also enabled. Option <NUM>, the configuration state is common for all HARQ processes and MAC CE or DCI indicated which state is assumed for the UE. The states may be indexed such that those can be referred by MAC CE or predefined ordering is assumed. first bit in MAC CE refers to first state in the list of configured states.

In some other embodiments, a combination of RRC and RNTI to activate/deactivate bundling for a specific HARQ process(es) is used.

In some other embodiments, DCI is used to configure bundling for a specific HARQ process(es).

In some other embodiments, given the mapping that configures the amount of bundles for each HARQ process ID, in MAC CE or DCI the amount of bundling on each HARQ process is controlled by either signalling increase, decrease or maintain. As an example, if the current bundling number is <NUM> for HARQ process ID <NUM>, then if MAC CE signals an increase on HARQ process ID then the bundling number is increased to <NUM>.

In case a UE is configured with bundling in both contiguous or non-contiguous mode, the UE can try to decode the data after each received TB within the bundle. In case the UE is able to decode the data, it can discard future TBs within the same bundle (same HARQ process ID), this will lead to energy savings at the UE side. Optionally, the UE can feedback to the NW indicating successful transmission of the TB and thus NW could terminate transmission early (instead of blindly sending aggregationFactor times of the TB).

Since the network is interested in sending as much information as possible, while minimizing the resource overhead. The UE can feedback the decoding information of the bundle to enable the network to set optimal TB sizes, bundling parameters, MCS, in order to optimize the resource utilization for future communication with said UE. The UE reported feedback could be, e.g.:.

A parameter for logical channel prioritization, LCP, that can be indicated in e.g. a grant is provided. According to the invention, if this indication is included, the UE may only include data from specific LCH that are allowed to send data on HARQ processes with HARQ Feedback disabled. If not included, any LCH are valid for the grant.

Example: HARQ process IDs <NUM> and <NUM> are configured to not send HARQ feedback. A grant is received in the UE to be used together with HARQ process ID = <NUM>. The LCP in the is then only allowed to include data from LCHs that indicates that data from these buffers are ok to be sent without feedback.

<FIG> illustrates the operation of a base station <NUM> and a UE <NUM> in accordance with at least some aspects of Embodiment <NUM>. Optional steps are represented with dashed lines. As illustrated, the base station <NUM> optionally determines (e.g., decides) an indication for mapping data (step <NUM>). The base station <NUM> provides to the UE <NUM> of an indication for mapping data that can be sent on one or more of specific HARQ processes (step <NUM>). This indication can be provided to the UE <NUM> in any suitable manner such as e.g. in a grant, indicated dynamically in the received DCI using a bit indication, indicated using a specific RNTI(s), indicated using a MAC CE, indicated semi-static signaling such as, e.g., Radio Resource Control (RRC) signaling, or the like.

At the UE <NUM>, the UE <NUM> receives the indication in step <NUM> (step <NUM>). The UE <NUM> and the base station <NUM> then perform transmission/reception of a transmission based on the received indication (step <NUM>).

In some embodiments, a repetition is configured for a certain logical channel with a certain logical channel priority. This can be configured directly by RRC in LogicalChannelConfig IE with a parameter giving the repetition order. This means then when receiving MAC SDU from such logical channel, MAC entity forms the configured number of MAC PDUs of the same MAC SDU.

<FIG> is a schematic block diagram of a radio access node <NUM> according to some embodiments of the present disclosure. The radio access node <NUM> may be, for example, the base station <NUM> or the combination of the base station <NUM> and the base station antenna <NUM> described above. As illustrated, the radio access node <NUM> includes a control system <NUM> that includes one or more processors <NUM> (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory <NUM>, and a network interface <NUM>. The one or more processors <NUM> are also referred to herein as processing circuitry. In addition, in some embodiments, the radio access node <NUM> includes one or more radio units <NUM> that each includes one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. The radio units <NUM> may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) <NUM> is external to the control system <NUM> and connected to the control system <NUM> via, e.g., a wired connection (e.g., an optical cable). For example, the control system <NUM> may be implemented in the base station <NUM>, and the radio unit(s) <NUM> and antennas <NUM> may be implemented in the base station antenna <NUM>. However, in some other embodiments, the radio unit(s) <NUM> and potentially the antenna(s) <NUM> are integrated together with the control system <NUM>. The one or more processors <NUM> operate to provide one or more functions of a radio access node <NUM> (e.g., one or more functions of the base station, eNB, or gNB) as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory <NUM> and executed by the one or more processors <NUM>.

As used herein, a "virtualized" radio access node is an implementation of the radio access node <NUM> in which at least a portion of the functionality of the radio access node <NUM> is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node <NUM> includes one or more processing nodes <NUM> coupled to or included as part of a network(s) <NUM> via the network interface <NUM>. Each processing node <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), memory <NUM>, and a network interface <NUM>. Optionally, the radio access node <NUM> includes the control system <NUM> and/or the radio unit(s) <NUM>, depending on the particular implementation.

In this example, functions <NUM> of the radio access node <NUM> described herein (e.g., functions of the base station, eNB, or gNB described herein) are implemented at the one or more processing nodes <NUM> or distributed across the control system <NUM> and the one or more processing nodes <NUM> in any desired manner. In some particular embodiments, some or all of the functions <NUM> of the radio access node <NUM> described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) <NUM>. Notably, in some embodiments, the control system <NUM> may not be included, in which case the radio unit(s) <NUM> can communicate directly with the processing node(s) <NUM> via an appropriate network interface(s).

<FIG> is a schematic block diagram of a UE <NUM> according to some embodiments of the present disclosure. As illustrated, the UE <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), memory <NUM>, and one or more transceivers <NUM> each including one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. The transceiver(s) <NUM> includes radio-front end circuitry connected to the antenna(s) <NUM> that is configured to condition signals communicated between the antenna(s) <NUM> and the processor(s) <NUM>, as will be appreciated by on of ordinary skill in the art. The processors <NUM> are also referred to herein as processing circuitry. The transceivers <NUM> are also referred to herein as radio circuitry. In some embodiments, the functionality of the UE <NUM> (i.e., the functionality of the UE) described above may be fully or partially implemented in software that is, e.g., stored in the memory <NUM> and executed by the processor(s) <NUM>. Note that the UE <NUM> may include additional components not illustrated in <FIG> such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other components for allowing input of information into the UE <NUM> and/or allowing output of information from the UE <NUM>), a power supply (e.g., a battery and associated power circuitry), etc..

With reference to <FIG>, in accordance with an embodiment, a communication system includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a RAN, and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 1306A, 1306B, 1306C, such as NBs, eNBs, gNBs, or other types of wireless Access Points (APs), each defining a corresponding coverage area 1308A, 1308B, 1308C. Each base station 1306A, 1306B, 1306C is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 1308C is configured to wirelessly connect to, or be paged by, the corresponding base station 1306C. A second UE <NUM> in coverage area 1308A is wirelessly connectable to the corresponding base station 1306A.

It is noted that the host computer <NUM>, the base station <NUM>, and the UE <NUM> illustrated in <FIG> may be similar or identical to the host computer <NUM>, one of the base stations 1306A, 1306B, 1306C, and one of the UEs <NUM>, <NUM> of <FIG>, respectively.

The wireless connection <NUM> between the UE <NUM> and the 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 the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve e.g., data rate, latency, and/or power consumption and thereby provide benefits such as e.g., reduced user waiting time, relaxed restriction on file size, better responsiveness, and/or extended battery lifetime.

Claim 1:
A method performed by a wireless device (<NUM>) for mapping data to specific HARQ processes for a non-terrestrial network supported in New Radio, NR, the method comprising:
receiving (<NUM>) an indication that maps data that can be sent on one or more of specific HARQ processes; and
transmitting/receiving (<NUM>) a transmission for a specific HARQ process of the one or more specific HARQ processes based on the received indication such that:
- when the indication comprises a parameter for logical channel prioritization, LCP, only data from specific logical channels, LCH, are included that are allowed to send data on HARQ processes with a HARQ feedback procedure disabled, based on the received indication; and
- when the indication does not comprise the parameter for LCP, the wireless device interprets that also LCH that are not allowed to send data on HARQ processes with the HARQ feedback procedure disabled are allowed to send data on the specific HARQ process.