Patent Description:
In modern communications system, capacity and reliability of communication is of great importance. Several methods for increased reliability are available and one such method is to use an automatic repeat request, ARQ, scheme. The ARQ scheme allows errors in received information bits to be corrected by retransmission of data. Generally, this may comprise one or several schemes of how and if a retransmission is to be performed, exemplary schemes are stop and wait, SAW, go-back-N, GBN, selective repeat, SR, etc..

In order to further increase reliability of communications, the ARQ scheme may be combined with a Forward Error Correction, FEC, scheme forming, what is commonly known as a Hybrid Automatic Repeat Request, HARQ, scheme. The FEC scheme allows incorrectly received information bits to be corrected by an added error correction code.

Generally, in an HARQ scheme, the receiving entity tries to perform error correction by means of the error correction code, and if error correction fails, a retransmission is requested by a negative acknowledge, NACK, is transmitted by the receiving entity to a transmitting entity. Upon reception of the NACK, the transmitting entity retransmits data in accordance with a HARQ mode and the receiving entity combines the retransmitted data with the previously, erroneously, received data, effectively improving the reliability of the communication. Analogously, if the reception of the information bits was successful, the receiving entity transmits a positive acknowledgement, ACK, to the transmitting entity and no retransmission is required.

In a HARQ scheme, information bits transmitted by the transmitting entity will require downlink DL capacity in the communications system for transfer, and each ACK/NACK transmitted by the receiving entities will require uplink UL capacity in the communications system. The number of UL resources for reporting ACK/NACK are limited and it may very well be that a UL link budget is worse than a corresponding DL link budget.

The <NPL>" discloses unidirectional relaying with an eRelay UE to relay UL control/data and ACK/NACK feedback on DL transmissions.

The <NPL>" discloses three options for sidelink resource configuration.

<CIT> discloses relay communication between a base station and a remote terminal via a relay terminal.

<CIT> discloses a method for enabling data rate relay operation using a Device-to-Device air interface for transmitting and receiving data via sidelink under control of an Evolved Node B.

The <NPL>" discloses a case where a Tx-UE receives resource allocation from a network node and then transmit SCI and data in sidelink.

<CIT> discloses a relay device for supporting communications between a terminal device and a base station.

Additional details are provided in the dependent claims.

It is in view of the above considerations and others that the various embodiments of this disclosure have been made. The present disclosure therefor recognizes the fact that there is a need for improvement of the existing art described above.

It is a general object of the embodiments described herein to provide a new type of method for transferring Hybrid Automatic Repeat Request, HARQ, positive Acknowledgement, ACK, or Negative Acknowledgement, NACK, in a wireless communication system which is improved over the prior art and which eliminates or at least mitigates one or more of the drawbacks discussed above. More specifically, an object of the embodiments discussed in this disclosure is to provide a method that enables L1 relaying.

In a first aspect, a method of transferring Hybrid Automatic Repeat Request, HARQ, positive Acknowledgement, ACK, or Negative Acknowledgement, NACK, in a wireless communication system is presented. The wireless communication system comprises a first wireless device, a second wireless device and a network node. The method comprises the network node transmitting a first transmission to the first wireless device. The first wireless device transmits, in response thereto, a first HARQ-ACK/NACK associated with the first transmission. Responsive to control information provided to the second wireless device indicating that the first HARQ-ACK/NACK is to be forwarded to the network node, the second wireless device relays the first HARQ-ACK/NACK to the network node.

In one variant, the first transmission is transmitted directly to the first wireless device. This is beneficial as it enables the relaying to be implemented selectively in the UL without affecting DL.

In one variant, the first wireless device determines if the first HARQ-ACK/NACK should be relayed by the second wireless device based on at least one of an uplink, UL, channel quality of the first wireless device, an UL channel resource availability of the first wireless device, an UL channel capacity of the first wireless device, and/or an urgency associated with the first HARQ-ACK/NACK. This is beneficial as the first wireless device may itself decide if the first HARQ-ACK/NACK should be relayed or not.

In one variant, the network node determines if the first HARQ-ACK/NACK should be relayed by the second wireless device based on at least one of an uplink, UL, channel quality of the first wireless device and/or the second wireless device, an UL channel resource availability of the first wireless device and/or the second wireless device, an UL channel capacity of the first wireless device and/or the second wireless device, and/or an urgency associated with the first HARQ-ACK/NACK. This is beneficial as the network node may itself decide if the first HARQ-ACK/NACK should be relayed or not.

In one variant, the first HARQ-ACK/NACK is transmitted across a sidelink responsive to that the first HARQ-ACK/NACK is to be relayed by the second wireless device. This is beneficial as the sidelink communication will not load the main UL/DL links and is extra beneficial if UL resources are scarce.

In one variant, the sidelink is one or more of a Physical Sidelink Feedback Channel, PSFCH, a Physical Sidelink Shared Channel, PSSCH, a Physical Sidelink Control Channel, PSCCH, a non-cellular communications link, a channel enabling physical layer decoding of HARQ-ACK/NACK, and/or a channel enabling higher-layer decoding of HARQ-ACK/NACK. This is beneficial as the sidelink communication will not load the main UL/DL links and is extra beneficial if UL resources are scarce.

In one variant the sidelink is selected by the first wireless device based on allocated resources provided by the network node. This is beneficial as the sidelink communication will not load the main UL/DL links and is extra beneficial if UL resources are scarce.

In one variant the sidelink is assigned by the network node. This is beneficial as the sidelink communication will not load the main UL/DL links and is extra beneficial if UL resources are scarce.

In one variant, the control information is provided to the first wireless device at least by the network node. This is beneficial as the network node possesses knowledge of network parameters that may be pertinent to the decision of relaying or not.

In one variant, the control information is provided to the second wireless device at least as an indication comprised in the first HARQ-ACK/NACK associated with first transmission. This is beneficial as it allows the decision to relay to be taken per HARQ-ACK/NACK.

In one variant, the wireless communication system further comprises one or more additional wireless devices. The method further comprises the network node transmitting an additional transmission to one of the one or more additional wireless devices. In response thereto, said one of the one or more additional wireless devices transmits an additional HARQ-ACK/NACK associated with the additional transmission. Responsive to control information provided to the second wireless device indicating that the additional HARQ-ACK/NACK and the first HARQ-ACK/NACK is to be forwarded to the network node, the second wireless device relays the first HARQ-ACK/NACK together with the additional HARQ-ACK/NACK to the network node. This is beneficial as several relayed HARQ-ACK/NACKs may be transmitted at the same time.

In one variant, the method further comprises the network node transmitting a second transmission to the second wireless device. The step of relaying further comprises relaying, by the second wireless device, a second HARQ-ACK/NACK associated with second transmission together with any other HARQ-ACK/NACK that are to be relayed to the network node. This is beneficial as the combination of several HARQ-ACK/NACK will reduce the signaling overhead and network load.

In one variant, the step of relaying comprises combining the first HARQ-ACK/NACK with any other HARQ-ACK/NACK that are to be relayed to the network node to provide a combined HARQ-ACK/NACK. The second wireless device relays the combined HARQ-ACK/NACK to the network node. This is beneficial as the combination of several HARQ-ACK/NACK will reduce the signaling overhead and network load.

In one variant, wherein at least one of the first transmission, the second transmission and/or the additional transmission are sent at different timeslots of a codebook. The HARQ-ACKs/NACKs associated with the transmissions that are sent at different timeslots and relayed by the second wireless device, are coded in one single line of the codebook. This is beneficial as the codebook size is reduced and thereby signaling overhead.

In one variant, wherein at least one of the first transmission, the second transmission and/or the additional transmission are sent at overlapping timeslots of the codebook, the HARQ-ACKs/NACKs associated with the transmissions sent at overlapping timeslots and relayed by the second wireless device, are coded on separate lines of the codebook, wherein each separate line is associated with a respective wireless device. This is beneficial as it allows a clear and straight forward association between a common codebook and the associated wireless devices.

In one variant only a HARQ-ACK is relayed. This is beneficial as it reduces network and signaling load.

In a second aspect, a first wireless device comprising one or more controllers is presented. Said one or more controllers are configured to, when the first wireless device is operable in a wireless communication system, perform the steps associated with first wireless device of the method according to the first aspect.

In a third aspect, a second wireless device comprising one or more controllers is presented. Said one or more controller are configured to, when the second wireless device is operable in a wireless communication system, perform the steps associated with second wireless device of the method according to the first aspect.

In a fourth aspect, an additional wireless device comprising one or more controllers is presented. Said one or more controllers are configured to, when the additional wireless device is operable in a wireless communication system, perform the steps associated with the additional wireless device of the method according to the first aspect.

In a fifth aspect, a network node comprising one or more controllers is presented. Said one or more controllers are configured to, when the network node is operable in a wireless communication system, perform the steps associated with network node of the method according to the first aspect.

In a sixth aspect, a wireless communication system comprising a first wireless device according to the second aspect, a second wireless device according to the third aspect and a network node according the fifth aspect.

In one variant, the wireless communication system further comprises an additional wireless device according to the fifth aspect.

Embodiments of the invention will be described in the following; references being made to the appended diagrammatical drawings which illustrate non-limiting examples of how the inventive concept can be reduced into practice.

Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention, such as it is defined in the appended claims, to those skilled in the art.

The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. Two or more items that are "coupled" may be integral with each other. The terms "a" and "an" are defined as one or more unless this disclosure explicitly requires otherwise. The terms "substantially," "approximately," and "about" are defined as largely, but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including") and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a method that "comprises," "has," "includes" or "contains" one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps.

Regarding scenarios and embodiments presented throughout this disclosure, albeit presented in specific terms, it should be understood that any specific terms may, unless otherwise is clearly stated, very well be replaced by more general, generic terms even if not explicitly specified. For example, the mentioning of specific signaling and control channel relating to e.g. specific cellular standards should be considered examples and this disclosure is, as the skilled person will appreciate after digesting the teachings herein, applicable to any suitable communication system, wireless or wired.

As mentioned earlier, the number of UL resources for reporting positive acknowledgement, ACK or negative acknowledgement, NACK, are limited and it may very well be that an uplink, UL, link budget is worse than a corresponding downlink, DL, link budget. This means that scenarios exist, wherein a wireless device, such as a User Equipment, UE, is unable to transmit an ACK/NACK to a network node. It may be that the capacity of a channel for transmitting ACK/NACK is limited or that frequency selective fading causes imbalance in the link budgets. Based on these findings, the inventors behind this disclosure have devised a method for improving the transmission of hybrid automatic repeat request, HARQ, in a wireless communication system. As will be clear to the person skilled in the art after digestion of the teachings of the present disclosure, the presented embodiments will e.g. reduce the risk of interferences between wireless devices, when e.g. one wireless device is at a location with poor signaling conditions, no additional latency is introduced as the case with e.g. Physical Uplink Control Channel, PUCCH, repetition, the required PUCCH resources are reduced increasing capacity of the wireless communication system and reduced and reduce the risk of HARQ ACK/NACK transmission errors.

With reference to <FIG>, a wireless communication system <NUM> according to an embodiment will be introduced. The wireless communication system <NUM> comprises a first wireless device <NUM>, a second wireless device <NUM> and a network node <NUM>. The first wireless device <NUM> and the second wireless device <NUM> are in wireless communication with the network node <NUM>. The network node <NUM> is configured to send transmissions to the first wireless device <NUM> and the second wireless device <NUM>. Responsive thereto, the first wireless device <NUM> and the second wireless device <NUM> are configured to transmit an ACK or NACK to the network node <NUM> indicating a successful or unsuccessful reception of the transmission from the network node <NUM> by the respective wireless device <NUM>, <NUM>. In addition to the, the wireless communication system <NUM> may further comprise one or more additional wireless devices <NUM>. Said one or more additional wireless devices <NUM> are in wireless communication with the network node <NUM>. The network node <NUM> is configured to send transmissions to said one or more additional wireless devices <NUM>. Responsive thereto, said one or more additional wireless devices <NUM> are configured to transmit an ACK or NACK to the network node <NUM> indicating a successful or unsuccessful reception of the transmission from the network node <NUM> by the respective additional wireless devices <NUM>. In addition to being in communication with the network node <NUM>, the wireless devices <NUM>, <NUM>, <NUM> may be in direct wireless communication with each other through a sidelink <NUM>. In the wireless communication system <NUM> of <FIG>, the first wireless device <NUM> and the second wireless device <NUM> are in communication across a sidelink <NUM>.

The following sections provide a brief introduction to the concept and configuration of sidelink communication. The sidelink <NUM> may, in e.g. New Radio, NR devices be scheduled either by the network node <NUM>, gNB, referred to as Mode <NUM>, or autonomously by the wireless device <NUM>, <NUM>, <NUM>, Mode <NUM>. In Mode <NUM>, the wireless device <NUM>, <NUM>, <NUM> selects sidelink resources from a (pre-)configured sidelink resource pool(s) based on a channel sensing mechanism. For the wireless devices <NUM>, <NUM>, <NUM> within coverage of a network node <NUM>, the network node <NUM> may be configured to adopt Mode <NUM> or Mode <NUM>. For wireless devices out-of-coverage, only Mode <NUM> can be adopted. For NR sidelink transmissions, at most one sidelink bandwidth part, BWP, may be configured on a carrier, and the minimum unit for resource scheduling in the frequency domain is a subchannel. Wherein a subchannel is composed of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> consecutive resource bocks, RBs, depending on practical configuration.

The sidelink <NUM> may be utilized as a layer <NUM> resource, which allows one wireless device <NUM>, <NUM>, <NUM> to relay data, generally a Protocol Data Unit, PDU, received from another wireless device <NUM>, <NUM>, <NUM> across the sidelink <NUM>. The methodology of using the sidelink <NUM> for relaying a PDU is described in e.g. 3GPP TR <NUM> V15.

For a NR wireless device, the sidelink <NUM> comprises a number of physical channels, a Physical Sidelink Control Channel, PSCCH, carrying control information in the sidelink; a Physical Sidelink Shared Channel, PSSCH, carrying a data payload, PDU, in the sidelink and additional control information; a Physical Sidelink Broadcast Channel, PSBCH, carrying information for supporting synchronization in the sidelink <NUM>; and a Physical Sidelink Feedback Channel, PSFCH, carrying feedback related to the successful or failed reception of a sidelink transmission. The PSFCH is transmitted by a sidelink receiving wireless device <NUM>, <NUM>, <NUM> for unicast and groupcast, which conveys <NUM>-bit information over <NUM> RB for the HARQ-ACK and the HARQ-NACK. In addition, channel state information, CSI, is carried in the medium access control, MAC, control element, CE, over the PSSCH instead of the PSFCH. In the time domain, a time gap between the PSSCH and the PSFCH is configured. However, when a receiving wireless device <NUM>, <NUM>, <NUM> sends the HARQ ACK/NACK on the PSFCH, only the transmitting wireless device <NUM>, <NUM>, <NUM> has the capability to receive such ACK/NACK messages, and a network node <NUM> cannot receive this feedback transmission. Consequently, a network node <NUM> may not know whether to further allocate resources for a transmitting wireless device <NUM>, <NUM>, <NUM> to retransmit a transport block, TB, or not. To obtain resources of the PSSCH for subsequent retransmissions, a transmitting wireless device needs to forward the sidelink HARQ ACK/NACK message to a network node when a feedback message is received on the PSFCH. To further obtain resources for a transmitting wireless device to send the sidelink HARQ ACK/NACK to a network node <NUM>, the network node <NUM> may allocate one physical uplink control channel, PUCCH, occurring after the last resource in the PSSCH set for initial sidelink transmissions. When a NACK is received by a network node <NUM>, the network node <NUM> further allocates PSCCH and PSSCH resources for sidelink retransmissions, and this resource allocation is indicated in a Downlink Control Information, DCI, field in the case of dynamic grant. Alternatively, a transmitting wireless device <NUM>, <NUM>, <NUM> may launch the TB retransmission through the reserved PSCCH and the PSSCH in a case of a configured grant. In the Mode <NUM> resource allocation, when traffic arrives at a transmitting wireless device <NUM>, <NUM>, <NUM>, this transmitting wireless device <NUM>, <NUM>, <NUM> is configured to autonomously select resources for the PSCCH and the PSSCH. To further minimize the latency of the feedback HARQ ACK/NACK transmissions and subsequently retransmissions, a transmitting wireless device <NUM>, <NUM>, <NUM> may also reserve resources for PSCCH/PSSCH for retransmissions.

The following sections provide a brief introduction to the concept and configuration of cellular transmissions, typically for NR devices. In NR, there are three types of HARQ-ACK code construction in NR, semi-static code construction, Type <NUM>, dynamic code construction, Type <NUM>, and one-shot feedback, Type <NUM>. The latter was introduced in 3GPP Rel-<NUM> for NR-U, in Rel-<NUM> for NR. The general procedure for receiving downlink, DL, transmission is that the wireless device <NUM>, <NUM>, <NUM> monitors and decodes a Physical Downlink Control Channel, PDCCH, in slot n which points to a DL data scheduled in slot n+K<NUM>, wherein K<NUM> is larger than or equal to zero. The wireless device <NUM>, <NUM>, <NUM> then decodes the data in the corresponding Physical Downlink Shared Channel, PDSCH. Finally, based on the outcome of the decoding the wireless device <NUM>, <NUM>, <NUM> sends an ACK of a correct decoding or a NACK of an incorrect decoding to the network node <NUM> at time slot n+ k<NUM>+k<NUM>, in case of slot aggregation, n+ K<NUM> would be replaced by the slot where the associated PDSCH ends. Both of K<NUM> and k<NUM> are indicated in the DCI. The resources for sending the acknowledgement are indicated by a Physical Uplink Control Channel, PUCCH, resource indicator, PRI, field in the DCI which points to one of PUCCH resources that are configured by higher layers.

Depending on e.g. a DL/UL slot configurations, or whether carrier aggregation or per code-block group, CBG, transmission is used in the DL, the feedback for several PDSCHs may need to be multiplexed in one single feedback. Generally, this is done by constructing HARQ-ACK codebooks. In NR, the wireless device <NUM>, <NUM>, <NUM> may be configured to multiplex the ACK/NACK bits using a semi-static codebook or a dynamic codebook.

Semi-static HARQ codebook, or Type <NUM> codebook, comprises a bit sequence where each element contains an ACK/NACK bit from a possible allocation in a certain slot, carrier, or TB. When the wireless device <NUM>, <NUM>, <NUM> is configured with a CBG and/or a time-domain resource allocation, TDRA, table with multiple entries; multiple bits are generated per slot and TB. It should be mentioned that the codebook is generally derived regardless of the actual PDSCH scheduling. The size and format of the semi-static codebook is generally preconfigured based on the mentioned parameters. The drawback of semi-static HARQ ACK codebook is that the size is fixed, and regardless of whether there is a transmission or not, a bit is reserved in the feedback matrix. In scenarios where the wireless device <NUM>, <NUM>, <NUM> has a TDRA table with multiple time-domain resource allocation entries configured; the table is pruned, i.e. entries are removed based on a specified algorithm in order to derive a TDRA table that only contains non-overlapping time-domain allocations. One bit is then reserved in the HARQ CB for each non-overlapping entry, that is assuming the wireless device <NUM>, <NUM>, 130is capable of supporting reception of multiple PDSCH in a slot.

In the dynamic HARQ codebook, or type <NUM> codebook, an ACK/NACK bit is present in a codebook only if there is a corresponding transmission scheduled. To avoid any confusion between the network node <NUM> and the wireless device <NUM>, <NUM>, <NUM> on the number of PDSCHs that the wireless device <NUM>, <NUM>, <NUM> is expected to send a feedback for, a counter downlink assignment indicator, DAI, field is available in the DL assignment. The DAI field denotes accumulative number of serving cell-PDCCH occasion pairs in which a PDSCH is scheduled to a wireless device <NUM>, <NUM>, <NUM> up to the current PDCCH. In addition to this, a total DAI field is available which, when present, shows the total number of serving cell-PDCCH occasions up to, and including, all PDCCHs of a current PDCCH monitoring occasion. The timing for sending HARQ feedback is determined based on both PDSCH transmission slot with reference to PDCCH slot k<NUM> and the PUCCH slot that contains HARQ feedback k<NUM>.

Assuming there are no errors in the downlink control signaling, a dynamic codebook would be straightforward. However, in the presence of an error in the downlink control signaling, the wireless device <NUM>, <NUM>, <NUM> and the network node <NUM> may have different understanding on the number of scheduled carriers, which would lead to an incorrect codebook size and possibly corrupt the feedback report for all carriers - and not only for the ones for which the downlink controls signaling was missed. If, by means of example, a wireless device <NUM>, <NUM>, <NUM> was scheduled for downlink transmission in two subsequent slots but missed the PDCCH and thereby the scheduling assignment for the first slot. As a result, the wireless device <NUM>, <NUM>, <NUM> will only transmit an acknowledgment for the second slot. The network node <NUM> on the other hand, tries to receive acknowledgments for both slots. This leads to mismatch. In NR, one way of mitigating this mismatch is by utilization of the downlink assignment index which is included in the DCI comprising the downlink assignment. The DAI field is further split into two parts, a counter DAI, cDAI, and, in the case of e.g. carrier aggregation, a total DAI, tDAI. The cDAI included in the DCI indicates the number of scheduled downlink transmissions up to the point the DCI was received in a carrier. The tDAI included in the DCI indicates the total number of downlink transmissions across all carriers up to this point in time, that is, the highest cDAI at the current point in time.

As present cellular wireless networks are defined, a wireless device <NUM>, <NUM>, <NUM> may be unable to reliably send a HARQ ACK/NACK to the network node <NUM> due to poor UL channel condition. As previously indicated, this may occur in frequency division duplex, FDD, systems in case of frequency selective fading where DL channels are good, but UL channels are poor. Similarly, valid also for time division duplex, TDD, an output power of a wireless device <NUM>, <NUM>, <NUM> may be reduced due to e.g. antenna loading causing mismatch affecting a gain of a transmitter power amplifier of the wireless device <NUM>, <NUM>, <NUM> more than a corresponding gain of a receiver low noise amplifier, LNA, of the wireless device <NUM>, <NUM>, <NUM>. Also, the wireless device <NUM>, <NUM>, <NUM> may have limited power for uplink transmission, e.g., it is a permanently low power device or its power may have been temporarily reduced.

There are situations where PUCCH resources for reporting a HARQ-ACK/NACK and other signaling may be limited. This may be exemplified by a scenario wherein there are heavy downlink data-consumers and a TDD pattern is devised such that higher downlink transmissions are provided in a TDD pattern. Assume a TDD pattern is of <NUM> DL + <NUM> UL slots wherein each DL slot is dedicated to one wireless device <NUM>, <NUM>, <NUM>. The wireless device <NUM>, <NUM>, <NUM> receiving data in the first DL slot, slot <NUM>, can report in timeslot <NUM>, while a wireless device <NUM>, <NUM>, <NUM> receiving its data in a second DL slot, slot <NUM>, will have to wait for a next available uplink slot.

In order to enhance PUCCH coverage, a wireless device <NUM>, <NUM>, <NUM> may apply repetitions for a PUCCH transmission up to a configurable number of times, e.g., <NUM>, <NUM> or <NUM>. One drawback with PUCCH repetition is that a wireless device <NUM>, <NUM>, <NUM> experiencing poor UL coverage may create interference to the other wireless device <NUM>, <NUM>, <NUM> with good coverage. In addition to this, additional latency, e.g., with <NUM> times of PUCCH repetitions, may be introduced. There may also be situations where there is an obstacle between a wireless device <NUM>, <NUM>, <NUM> and its network node <NUM>. In such situations, increasing the PUCCH transmitted power or applying PUCCH repetition may not help in improving PUCCH coverage.

An alternative approach is to let a wireless device <NUM>, <NUM>, <NUM> with poor UL coverage connect to the network node via a relay wireless device <NUM>, <NUM>, <NUM>. As network relay is currently being developed, e.g. 3GPP Rel-<NUM>. Relay architectures are only feasible to enable a relaying wireless device to relay data and control signaling above L2 of a remote wireless device to the network node <NUM>. In other words, with current or planned relay architectures, it is not feasible to relay L1 signaling of a wireless device <NUM>, <NUM>, <NUM> by another wireless device <NUM>, <NUM>, <NUM> to the network node <NUM>.

The inventors behind this disclosure have realized that it would be beneficial to, in the light of the above issues, develop mechanisms to enable a relay wireless device <NUM>, <NUM>, <NUM> to relay L1 signaling of a remote wireless device <NUM>, <NUM>, <NUM> to a network node <NUM>. By configuring a wireless communications network <NUM> such that a first wireless device <NUM> receives HARQ-ACK feedbacks from a second wireless device <NUM> and optionally from one or more additional wireless devices <NUM>, the first wireless device may combine the feedback(s) of the wireless devices <NUM>, <NUM> with its own HARQ-ACK feedback and transmits the feedbacks to the network node <NUM>. This may be accomplished by configuring the firs wireless device <NUM> such that it utilizes the PUCCH to sends HARQ-ACK information. However, historically, all HARQ-ACKs sent on a PUCCH by the first wireless device <NUM> would belong to the first wireless device <NUM> only. In the present disclosure, changes in PUCCH are allowed making it possible for the first wireless device to send HARQ-ACK information belonging to multiple wireless devices, including itself.

Turning now to the simplified signaling diagram of <FIG>, four different signaling scenarios A-D will be introduced. Signals are indicated as horizontal lines, and a direction of the signals is indicated by an arrow pointing to the receiver of the signal. In <FIG>, from the right, the vertical lines illustrate the network node <NUM>, the second wireless device <NUM>, the first wireless device <NUM> and the additional wireless devices <NUM>.

In signaling scenario A of <FIG>, the network node <NUM> sends a first transmission <NUM> to the first wireless device <NUM>. In response to the first transmission <NUM>, the first wireless device <NUM> sends a first HARQ-ACK/NACK <NUM> to the network node <NUM>. Scenario A is a typical way of signaling a HARQ-ACK/NACK in a communications network <NUM>.

In signaling scenario B of <FIG>, the network node <NUM> still sends a first transmission <NUM> to the first wireless device <NUM>, but rather having the first wireless device <NUM> sends the first HARQ-ACK/NACK <NUM> to the network node, the first HARQ-ACK/NACK <NUM> is received by the second wireless device <NUM> which in turn sends the first HARQ-ACK/NACK <NUM> to the network node. In other words, the first HARQ-ACK/NACK <NUM> from the first wireless device <NUM> is relayed to the network node <NUM> by the second wireless device <NUM>. The wireless device <NUM>, <NUM>, <NUM> acting as a relay may, in sections of this disclosure be referenced to as a coordinator wireless device <NUM>, <NUM>, <NUM>. Any of the devices mentioned herein may be the coordinator wireless device <NUM>, <NUM>, <NUM>, but for consistency and simplicity of explanation, the second wireless device <NUM> will typically be the coordinator wireless device <NUM>, <NUM>, <NUM> relaying HARQ-ACK/NACKs <NUM>, <NUM>, <NUM>. As will be detailed elsewhere, the first wireless device may or may not be aware of the first HARQ-ACK/NACK <NUM> being relayed or not. Scenario B may be a scenario in which the first wireless device <NUM> is experiencing transmit difficulties from e.g. UL/DL link budget mismatch.

In signaling scenario C of <FIG>, the network node <NUM> again sends a first transmission <NUM> to the first wireless device <NUM>, but in this scenario, also sends a second transmission <NUM> to the second wireless device <NUM>. The second wireless device <NUM> receives the first HARQ-ACK/NACK <NUM> from the first wireless device and combines this with a second HARQ-ACK/NACK <NUM> of the second wireless device <NUM> being in response to the second transmission <NUM>. The second wireless device <NUM> sends the combined HARQ-ACK/NACK <NUM>, <NUM> to the network node <NUM>. As in scenario B, the first HARQ-ACK/NACK <NUM> from the first wireless device <NUM> is relayed to the network node <NUM> by the second wireless device <NUM>, but in scenario C, the second wireless device <NUM> sends the first HARQ-ACK/NACK <NUM> together with the second HARQ-ACK/NACK <NUM>.

Analogously, in signaling scenario D of <FIG>, the network node sends a first transmission <NUM> to the first wireless device, a second transmission to the second wireless device <NUM> and an additional transmission <NUM> to the additional wireless device <NUM>. In this scenario, the second wireless device <NUM> receives, from the first wireless device <NUM> a first HARQ-ACK/NACK <NUM> associated with the first transmission <NUM> and, from the additional wireless device <NUM>, an additional HARQ-ACK/NACK <NUM> associated with the additional transmission <NUM>. The second wireless device <NUM> sends its own second HARQ-ACK/NACK <NUM> associated with the second transmission <NUM> to the network node together with the first HARQ-ACK/NACK <NUM> and the additional HARQ-ACK/NACK <NUM>.

From <FIG>, it is clear that by allowing the second wireless device <NUM> to relay HARQ-ACK/NACK <NUM>, <NUM> from other wireless devices <NUM>, <NUM> problems previously presented are solved.

The second wireless device <NUM> is preferably configured to relay HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM>, and as illustrated in <FIG>, the configuration of relay of HARQ-ACK/NACK <NUM>, <NUM> may be provided as control information <NUM> from the network node <NUM> and/or from the other wireless devices <NUM>, <NUM>. In embodiments wherein the control information <NUM> is provided by the network node, the control information <NUM> may be transmitted as e.g. uplink control information, UCI on the PUCCH or multiplexed with the PUSCH. When the control information <NUM> is provided by the other wireless devices <NUM>, <NUM>, it may be sent as a direct control message or preferably comprised in the HARQ-ACK/NACK <NUM>, <NUM> to be relayed. The control information <NUM> is preferably communicated across the sidelink <NUM>. When provided by the network node <NUM>, the network node <NUM> may send DCI, i.e. dynamic PDSCH grant or SPS activation DCI or new DCI, to the second wireless device <NUM> indicating that the second wireless device <NUM> is to collect HARQ-ACK/NACK from other wireless devices <NUM>, <NUM> and relay the collected HARQ-ACK/NACK to the network node <NUM>. The other wireless devices <NUM>, <NUM> may be e.g. wireless devices <NUM>, <NUM> in a proximity of the second wireless device <NUM> allowing the other wireless devices <NUM>, <NUM> to communicate with UE1 via device to device, D2D, communication technologies, e.g., the SL <NUM>. The control information <NUM> may comprise e.g. one or more flags indicating whether the HARQ-ACK/NACK of the other wireless devices <NUM>, <NUM> may be combined or not, identities of the other wireless devices <NUM>, <NUM> etc..

In order to relay HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM>, the second wireless device <NUM> preferably receives the HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM> prior to the relaying. The channel, medium or communication path across which the second wireless device <NUM> received the HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM> will be exemplified in the following, it should be emphasized that these are exemplary embodiments, and several others being within the scope of this disclosure may come to the mind of the skilled person after reading the following.

The HARQ-ACK/NACK <NUM>, <NUM> to be relayed may be received by the second wireless device <NUM> on the PSFCH of the SL from the first wireless device <NUM>. A modified channel over which HARQ-ACK/NACK <NUM>, <NUM> information of the first wireless device <NUM> is transmitted to the second wireless device <NUM> may be formed e.g. by adding bit(s) in the transmitted information over PSFCH indicating that the HARQ-ACK/NACK <NUM>, <NUM> feedback is related to the first wireless device <NUM> transmitted over sidelink channel.

The HARQ-ACK/NACK <NUM>, <NUM> to be relayed may be received by the second wireless device <NUM> PSSCH on the SL from the first wireless device <NUM>. The HARQ-ACK/NACK <NUM>, <NUM> information of the first wireless device <NUM> may be multiplexed with data from first wireless device <NUM> sent over PSSCH to the second wireless device.

In some embodiments, the HARQ-ACK/NACK <NUM> information of the first wireless device <NUM> may be carried by PC5-RRC, the HARQ-ACK/NACK <NUM> information of the first wireless device <NUM> may be carried by MAC CE, or the HARQ-ACK/NACK <NUM> information of the first wireless device <NUM> may be carried by control a PDU of a protocol layer such as SDAP, PDCP, RLC, or an adaption protocol layer designed for Sidelink relay.

In one embodiment, the HARQ-ACK/NACK <NUM> of the first wireless device <NUM> may be sent over PSCCH using an existing SCI format, e.g. repurpose existing fields in the SCI format, or by using a new SCI format defined for relaying HARQ-ACK/NACK <NUM>, <NUM> information of neighbor UEs.

In some embodiments, other licensed or unlicensed radio access technologies, RAT, are used e.g. Bluetooth, Zigbee, LoRa, WIFI, are used for communicating the HARQ-ACK/NACK <NUM>, <NUM> to be relayed to the second wireless device <NUM>. Any suitable protocol such as TCP/IP, proprietary protocols etc. may be utilized.

In some embodiments, a new channel may be introduced which enables physical layer decoding of HARQ-ACK/NACK <NUM>, <NUM> transmission sent from other transmitting wireless devices <NUM>, <NUM> by the receiving wireless device <NUM>, e.g. the second wireless device <NUM>. Subsequent to decoding, the receiving wireless device <NUM> may retransmit that information by optionally including its own information to the network node <NUM>.

In some embodiments, a new channel which enables higher-layer decoding of HARQ-ACK/NACK <NUM>, <NUM> transmission which are sent from other transmitting wireless devices <NUM>, <NUM> by the receiving wireless device <NUM>, e.g. the second wireless device <NUM>. Subsequent to decoding, the receiving wireless device <NUM> may retransmit that information by optionally including its own information to the network node <NUM>.

In some embodiments, for autonomous resource selection, the preferred scenario is where the network node <NUM> allocates a certain spectrum pool, carriers or resource for HARQ-ACK/NACK <NUM>, <NUM> transmission from the first wireless device <NUM> to the second wireless device <NUM>. For example, if the first wireless device <NUM> receives PDSCH from the network node <NUM> and it want sends to HARQ-ACK/NACK <NUM> to the network node <NUM> via relaying over the second wireless device <NUM>, then the first wireless device may autonomously select resources, i.e. PRBs from given spectrum pool, to transmit HARQ-ACK/NACK <NUM> codebook to the second wireless device <NUM>.

As disclosed above with some exemplifying embodiments, the second wireless device <NUM> may be provided with information regarding e.g. medium and resource allocation for relaying of HARQ-ACK/NACK <NUM>, <NUM> from other wireless devices <NUM>, <NUM>. It should be mentioned that there may be further embodiments to this, in one embodiment, the network node <NUM> informs the first wireless device <NUM> to send its HARQ-ACK/NACK <NUM> information via the second wireless device <NUM> and accordingly the network node <NUM> may be configured to assign sidelink resources for transmitting HARQ-ACK/NACK <NUM>, <NUM> feedbacks of other wireless devices <NUM>, <NUM> to the second wireless device. In another embodiment, the resources are awarded to the first wireless device <NUM>, but the decision of HARQ-ACK/NACK <NUM> information transmission is left to the first wireless device <NUM>, that is to say, resources are allocated by the network node <NUM>, but the transmission decision is autonomously made by the first wireless device <NUM>. For instance, the first wireless device may be configured such that when it is able to transmit via UL, i.e. directly to the network node <NUM>, it does so, otherwise the first wireless device <NUM> may relay the HARQ-ACK/NACK <NUM> information to the second wireless device <NUM>, e.g. if UL channel is bad. In one embodiment, the first wireless device <NUM> may be configured to transmit HARQ-ACK/NACK <NUM> on both UL and via the second wireless device <NUM> for increased reliability. This option may be useful in situations where the UL for the first wireless device <NUM> is not reliable due to e.g. rapid fluctuations, fading etc. As an additional embodiment, the first wireless device may decide to forward its HARQ-ACK/NACK <NUM> information to the second wireless device in situations when there is no available PUCCH resource or PUSCH resource to transmit the HARQ-ACK/NACK <NUM> information in the closing time while the HARQ-ACK information is delay critical e.g., for URLLC. In this situation, the HARQ-ACK/NACK <NUM> information may be relayed to the network node <NUM> via the second wireless device <NUM> in order to reduce latency.

The control information <NUM> may comprise information indicating what resources to utilize when relaying HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM>. In embodiments wherein the network node <NUM> allocate resources, the resources for relaying HARQ-ACK/NACK <NUM>, <NUM> may comprise, but are not limited to, HARQ-ACK/NACK resources in specific cells/carriers, HARQ-ACK/NACK resources in specific BWPs of the same serving cell where the PDSCH receptions associated with the HARQ ACK occur, HARQ-ACK/NACK resources transmission using specific Transmission Reception Points, TRPs, DCI allocated HARQ-ACK/NACK resources indicated in a specific CORESET, and/or DCI allocated HARQ-ACK/NACK resources indicated by using specific DCI format. In the exemplified embodiment, the second wireless device <NUM> may relay HARQ-ACK/NACK <NUM>, <NUM> from the other wireless devices <NUM>, <NUM> utilizing e.g. MAC CE in PUSCH using a configured grant or a dynamic grant, RRC signaling in PUSCH using a configured grant or a dynamic grant etc..

The relaying functionality may, as exemplified above, be under control of the network, e.g. the network node <NUM> or in the case of NR, a scheduler in a gNB. This allows the network node <NUM> to schedule the second wireless device to perform, or not to perform relaying based on RRC parameter or DCI parameter. In other embodiments, the network node <NUM> may permit the second wireless device <NUM> to relay only the HARQ-ACK/NACK <NUM>, <NUM> information of a permitted list of wireless devices <NUM>, <NUM>. That is to say, the second wireless device <NUM> only acts as relay for the wireless devices <NUM>, <NUM> that are specified in a list provided by the network node <NUM>. The list of wireless devices <NUM>, <NUM> where relaying is permitted may be provided to the second wireless device by RRC parameter or DCI parameter. The list of wireless devices <NUM>, <NUM> where relaying is permitted may be comprised in the control information <NUM>. In another embodiment, the network node <NUM> may permit the second wireless device to relay HARQ-ACK/NACK <NUM>, <NUM> information for specific services. For example, the relaying of only HARQ-ACK information of URLLC services is allowed but not eMBB or CMTC services. As the skilled person appreciates, the above listed embodiments are in no way strict alternatives but may be freely combined and the network node <NUM> may be configured to permit the second wireless device <NUM> to relay any combination of the above examples. For example, the relying of URLLC services of a permitted list of wireless devices <NUM>, <NUM> is one workable embodiment.

In some embodiments, a wireless device <NUM>, <NUM>, <NUM>, i.e. the first wireless device <NUM> or the additional wireless device <NUM> from the non-limiting examples of this disclosure, may under some conditions be configured to send HARQ-ACK/NNACK <NUM>, <NUM> feedback on the UL and in under other conditions via relaying. UL transmission may be utilized when e.g. when a UL radio quality is above a UL quality threshold and relaying, relaying via the second wireless device <NUM>, over SL when the UL radio quality is below the UL quality threshold. One advantage of this is that the delay is reduced if the direct HARQ-ACK/NACK <NUM>, <NUM> feedback over UL is successful, compared to if only the relayed feedback is successful as there is generally an added delay when relaying. In this case one further embodiment, the first wireless device <NUM> is configured with two k1 values in DCI, e.g., the first k1 value is used to indicate the offset from PDSCH transmission to the direct HARQ feedback transmission over UL resource. The second k1 value is the offset from the PDSCH transmission to the relayed HARQ feedback transmitted/relayed to the second wireless device <NUM> over SL resource. In alternative embodiment, there is one k1 value in DCI, either it is used to transmit e.g. feedback in UL or transmit feedback over SL to the second wireless device <NUM>.

In one embodiment, the relay selection/reselection may occur independent of the first wireless device <NUM> needs to transmit/relay its HARQ-ACK/NACK <NUM> information. Due to e.g. the first wireless device <NUM> being mobile or varying channel conditions, a new coordinator wireless device <NUM>, <NUM> for relaying may be selected based on parameters such as signal strength, path loss, etc. for the first wireless device's L1 HARQ-ACK/NACK <NUM> information relaying capabilities. When a new coordinator wireless device is selected, and if there is a need to transmit HARQ-ACK/NACK <NUM>, <NUM>, <NUM> information, then first wireless device may be configured to send it via the new coordinator wireless device instead of via the old coordinator wireless device <NUM>, the second wireless device. In other words, the second wireless device <NUM> is replaced by new coordinator wireless device for relaying the first wireless device's L1 HARQ-ACK information. This means that the first wireless device <NUM> continually/semi-persistently e.g. after every N slots/time units, scan the received signal strength from the neighboring wireless devices <NUM>, <NUM> and the network node <NUM> to determine/select the best node to receive its UL transmission directly, which may be a wireless device, acting as a coordinator wireless device, or the network node <NUM>. Alternatively, the first wireless device may be configured to trigger a relay selection/reselection when a current sidelink <NUM> between the first wireless device <NUM> and the second wireless device <NUM> has channel quality below a configured sideling quality threshold e.g. for a configured time period.

In one embodiment, a group of wireless devices <NUM>, <NUM> is determined. The group of wireless devices <NUM>, <NUM> is configured to transmit their HARQ-ACK <NUM>, <NUM> information via the coordinator wireless device <NUM>. The network node <NUM> may be configured to group wireless devices <NUM>, <NUM>, <NUM> based on one or more conditions where one condition may relate to a path loss between wireless devices e.g., the path loss between a wireless device <NUM>, <NUM>, <NUM>, and the coordinator wireless device <NUM>. If this path loss is below a path loss threshold, the wireless device <NUM>, <NUM>, <NUM> may be added to the group of wireless devices <NUM>, <NUM>, <NUM>. Another condition may relate to a channel quality, e.g. if UL channel, over which HARQ-ACK CB is supposed to be transmitted is poor, then a nearby wireless device is chosen as coordinator wireless device so that the coordinator wireless device may relay the HARQ-ACK/NACK information of the wireless device suffering from poor UL. The channel quality may be measured and analyzed using indicators such UL signal strength and quality, RSRP, RSRQ, CSI report, etc. Another condition may relate to applications, services and/or traffic types. Wireless devices <NUM>, <NUM>, <NUM> may be grouped in case they have similar/same application, service, or traffic type as these may imply that they have similar traffic pattern and/or QoS requirements.

In one embodiment, the coordinator wireless device <NUM> combines HARQ-ACK/NACK of itself and at least one other wireless device <NUM>, <NUM> based on a priority of the HARQ-ACK/NACK. Combination of feedback may, in this embodiment be considered if the HARQ-ACK/NACK <NUM>, <NUM> of both wireless devices <NUM>, <NUM> belongs to same priority, if the HARQ-ACK/NACK <NUM>, <NUM> of both wireless devices <NUM>, <NUM> belongs to mix of priority. The mix of priority may be exemplified by the coordinator wireless device having high priority HARQ-ACK/NACK <NUM>, and the first wireless device <NUM> has low priority HARQ-ACK/NACK <NUM>, or if both the coordinator wireless device <NUM> and the first wireless device <NUM> has a mix of high and low priority HARQ-ACK/NACK <NUM>, <NUM>.

Albeit this disclosure mainly focuses on relaying of HARQ-ACK and HARQ-NACK, it should be emphasized that in embodiments, it is possible that either the coordinator wireless device <NUM> or any of the wireless devices <NUM>, <NUM> whose information is to be forwarded, may be configured to only relay a HARQ-ACK or a HARQ-NACK. For the wireless devices <NUM>, <NUM> whose information is to be forwarded, this will reduce the signaling required between the coordinator wireless device <NUM> and the wireless devices <NUM>, <NUM> whose information is to be forwarded, thereby saving power and reducing spectrum load. Where coordinator wireless device <NUM> is configured to only forward HARQ-ACK, this also reduces power consumption and spectrum load and is further beneficial as the network node <NUM> may be configured to retransmit a PDSCH if an associated HARQ-ACK is not received within a predetermined time period from the initial transmission of the PDSCH.

It should be mentioned that in some embodiments, whether HARQ-ACK information of e.g. the first wireless device <NUM> can be relayed via a neighboring wireless device, e.g. the second wireless device <NUM>, may be configurable per service, traffic type, LCH or LCG. This means that the first wireless device <NUM> would only forward the HARQ-ACK associated with specific services, traffic types, LCHs or LCGs, which may be associated with specific Quality of Service, QoS, requirements. As a further embodiment, a first capability bit is defined. The first capability bit indicate whether an associated wireless device <NUM>, <NUM>, <NUM> supports to forward its HARQ-ACK information to the coordinator wireless device. As a further embodiment, a second capability bit is defined, indicating whether the associated wireless device <NUM>, <NUM>, 130may be configured to work as coordinator wireless device for other wireless devices.

In one embodiment, DL DCI, e.g. DCI format 1_1, received by a wireless device <NUM>, <NUM>, <NUM> includes a field indicating whether the HARQ ACK timing indicator K1 in the DCI refers to the wireless device <NUM>, <NUM>, <NUM> from which the DL DCI was received, or to another wireless device <NUM>, <NUM>, <NUM>. In case K1 refers to another wireless device <NUM>, <NUM>, <NUM>, an ID of the wireless device <NUM>, <NUM>, <NUM> referred to may also be carried in the DCI.

In the following sections, exemplifying embodiments of how a coordinator wireless device <NUM> may configure a transmission of HARQ-ACK/NACK when relaying HARQ-ACK/NACK from other wireless devices <NUM>, <NUM>.

With reference to <FIG>, one embodiment of HARQ-ACK/NACK <NUM>, <NUM>, <NUM> slot configuration will be described exemplified with the first transmissions <NUM> and the second transmission <NUM> as previously introduced. The HARQ-ACK/NACK feedback transmissions <NUM>, <NUM> of the first wireless device <NUM> and the second wireless device <NUM> are configured such that their DL HARQ processes do not overlap in the time-domain. In <FIG>, four slots S1-S4 are illustrated out of which the second transmissions <NUM> are present in a first slot S1 and a third slot S3. In <FIG>, which illustrate the same four slots S1-S4 as <FIG>, the first transmission <NUM> is present in a second slot S2. With this, the Type <NUM> CB construction for the feedback associated with multiple PDSCHs of multiple wireless devices may be configured as illustrated in <FIG>. The PDSCHs of the two wireless devices <NUM>, <NUM> do not overlap, hence, in the CB construction, the HARQ-ACK/NACK feedback of the first wireless device <NUM> and the second wireless device <NUM> are combined in one row of HARQ-ACK/NACK codebook. As seen in a codebook <NUM> illustrated in <FIG>, the first wireless device <NUM> and the second wireless <NUM> device have been configured with one TDRA entry in a slot. The second wireless device <NUM> is allocated with two transmissions in the first slot S1 and the third slot S3, respectively with k1=<NUM> and k1=<NUM>. The second wireless device <NUM> has been configured with a transmission in the second slot S2 with k1=<NUM>.

As illustrated in <FIG>, the codebook <NUM> may be transmitted by the coordinator wireless device <NUM> at a next available UL slot. In one embodiment, the UL slot for transmission of the codebook <NUM> is a slot following an eighth DL slot S8.

In one embodiment, illustrated in <FIG>, multiple PDSCHs allocations for different wireless devices overlap in time-domain. Therefore, in this case, HARQ-ACK/NACK information for different wireless devices cannot be transmitted as exemplified with reference to <FIG>. As seen in <FIG>, the first wireless device <NUM> and the second wireless device have the same configured TDRA entries in a slot or a time window, both wireless devices <NUM>, <NUM> have transmissions scheduled in the first slot S1, with k1=<NUM>, and the second wireless device <NUM> also have transmission scheduled in the third slot S3, with k1=<NUM>. In this embodiment, the coordinator wireless device <NUM> constructs CB <NUM> where HARQ-ACK information of both the first wireless device <NUM> and the second wireless device in one codebook <NUM> are mapped to two rows, each of which representing HARQ-ACK/NACK information of a wireless device. In a further embodiment, the coordinator wireless device <NUM> is configured to indicate an ID of a wireless device <NUM>, <NUM> for each row of the CB <NUM>. In order to reduce the size of the codebook <NUM>, the indicated ID may be a relative index, e.g. if the first wireless device <NUM> and the second wireless device <NUM> forms a group to help each other for relaying HARQ-ACK/NACK; a single bit field with value may indicate each wireless device <NUM>, <NUM>. For multiple wireless devices <NUM>, <NUM>, <NUM> in a group, a bitmap field may be introduced to indicate wireless devices <NUM>, <NUM>, <NUM> in the group. In an additional or alternative embodiment, the network node <NUM> has prior knowledge of which row is associated with which wireless device <NUM>, <NUM>.

As further embodiments to the CB <NUM> embodiments above, there may be scenarios, as illustrated in <FIG> where different wireless devices <NUM>, <NUM>, <NUM> are configured with different TDRA entries which may result in different number of HARQ-ACK/NACK bits for different wireless devices, see <FIG>. These scenarios it may be beneficial to further extend the codebook <NUM> by adding columns to correspond to the largest number of bits of each wireless device, <FIG>.

Additionally or alternatively, the codebook <NUM> may be constructed based on HARQ-ACK/NACK priority.

In embodiments wherein a type <NUM> codebook <NUM> is utilized, the coordinator wireless device may be configured to construct a type <NUM> CB which contains HARQ-ACK/NACK information of itself any additional wireless device <NUM>, <NUM>, <NUM> from which a HARQ-ACK/NACK is to be relayed. For type <NUM> CB construction, the coordinator wireless device <NUM> preferably has knowledge of the number of transmissions <NUM>, <NUM>, <NUM> itself and the additional wireless devices <NUM>, <NUM>, <NUM> are allocated with. This may be accomplished by the coordinator wireless device having knowledge related to the tDAI of the additional wireless devices <NUM>, <NUM>, <NUM>.

For simplified explanation, cDAI,UE1 indicates the number of scheduled transmissions for the coordinator wireless device <NUM> up to a time at which the DCI to the coordinator wireless device is received; tDAI,UE1 indicates the total number of transmissions for all carriers of the coordinator wireless device <NUM> up to this point in time, and tDAI,UE2 indicates the total number of transmissions for all carriers of the first wireless device <NUM> up to this point in time. As mention, in order to construct Type <NUM> CB <NUM>, the coordinator wireless device <NUM> preferably knows about the total number of transmission in the first wireless device <NUM>.

In one embodiment of type <NUM> codebook <NUM>, in DCI, DAI counters are set by the network node <NUM> as {cDAI,UE1, tDAI,UE1+ tDAI,UE} which are sent to the coordinator wireless device <NUM> and as {cDAI,UE2, tDAI,UE2} which are sent to the first wireless device <NUM>. The counters tDAI,UE1+ tDAI,UE2 indicate the total number of allocated transmissions across all carriers of the first wireless device <NUM> and the coordinator wireless device <NUM> up to this point in time. Next, if the first wireless device <NUM> transmits its HARQ-ACK information, Type <NUM> CB <NUM> of the first wireless device <NUM>, to the coordinator wireless device <NUM> over SL, and in addition, the coordinator wireless device <NUM> has knowledge of the total DAI, i.e. tDAI,UE1+ tDAI,UE2, e.g. as indicated in the PDSCH allocation's DCI of the coordinator wireless device <NUM> or sent in some DCI. Consequently, the coordinator wireless device <NUM> can transmit NACK for non-reported transmissions by the first wireless device or the coordinator wireless device <NUM>.

In another embodiment, similar to the one above, instead of total DAI as tDAI,UE1+ tDAI,UE2, the network node <NUM> may be configured to indicate total DAIs separately, where the DAI counters are set as {cDAI,UE1,tDAI,UE1, tDAI,UE2} which are sent to the coordinator wireless device <NUM> and as {cDAI,UE2,tDAI,UE2} which is sent to the first wireless device <NUM>.

In another embodiment, the first wireless device <NUM> sends its CB <NUM>, which may be Type-<NUM>, Type-<NUM> or one-shot to the coordinator wireless device <NUM>. The coordinator wireless device <NUM> attaches/concatenates its Type <NUM> CB <NUM> to the received CB <NUM> of the first wireless device <NUM> and transmits this bigger sized CB <NUM> to the network node <NUM>. If the network node <NUM> possesses knowledge of how these two codebooks <NUM> are attached, then there is no need to add the IDs of the wireless devices <NUM>, <NUM> as key to the bigger sized CB <NUM>. Otherwise, the coordinator wireless device <NUM> preferably adds the IDs of the wireless devices <NUM>, <NUM> at relevant places of the CB <NUM>, e.g. at the starting of each wireless device's codebook <NUM>.

The teachings herein are workable also when one-shot codebook is utilized. In one such embodiment, an enhancement of a one-shot codebook <NUM> transmitted by the coordinator wireless device <NUM> to the network node <NUM> wherein the codebook <NUM> contains the HARQ-ACK information of both the coordinator wireless device <NUM> and the first wireless device <NUM> for all HARQ processes. This may be exemplified in two embodiments.

In one embodiment, the HARQ process IDs, PIDs, are not shared. For example, per carrier, each UE may be allocated maximum <NUM> HARQ processes, then the coordinator wireless device <NUM> comprises HARQ-ACK information for all <NUM> HARQ processes of the coordinator wireless device <NUM> and the first wireless device in the CB <NUM>. Consequently, the first wireless device <NUM> is preferably configured to provide the coordinator wireless device <NUM> with HARQ-ACK information of all its <NUM> or active HARQ processes. The coordinator wireless device <NUM> may be configured to assume NACK for any HARQ processes which the first wireless device did not provide. The codebook may be formed as [{UE#<NUM>-ID}{PID<NUM>-A/N,. ,PID<NUM>-A/N}, {UE#<NUM>-ID}{PID<NUM>-A/N,. ,PID<NUM>-A/N}].

In another embodiment, the HARQ processes are shared between the coordinator wireless device <NUM> and the first wireless device. In this embodiment, the coordinator wireless device <NUM> is preferably configured to transmit HARQ-ACK information of only <NUM> HARQ processes. For example, out of <NUM> per CB <NUM>, the first <NUM> HARQ processes may be allocated to the coordinator wireless device <NUM> and the last <NUM> HARQ processes may be allocated to the first wireless device, then the CB <NUM> may be formed as [{PID<NUM>-A/N,. ,PID<NUM>-A/N}].

Based the teachings of the present disclosure, a method of transferring HARQ-ACK/NACK <NUM> will be presented with reference to <FIG>. The method <NUM> is preferably adapted for use in a wireless communication system <NUM>, but may in fact be used in any type of communication system. <FIG> is a schematic overview of the method <NUM> and <FIG> is a signaling overview similar to that of <FIG> but with the corresponding method steps illustrated. The method <NUM> may be performed in a wireless communication system <NUM> comprising a network node <NUM>, a first wireless device <NUM> and a second wireless device <NUM>. These devices <NUM>, <NUM>, <NUM> may be any according to any embodiment of this disclosure. The network node <NUM> transmits <NUM> a first transmission <NUM> to the first wireless device <NUM>. As a response to the transmitted <NUM> first transmission <NUM>, the first wireless device <NUM> transmits <NUM> a first HARQ-ACK/NACK <NUM> which is associated with the first transmission <NUM>. The second wireless device <NUM> is provided with control information <NUM> indicating that the second wireless device <NUM> is to forward HARQ-ACK/NACK <NUM> from at least the first wireless device <NUM> to the network node <NUM>. Based on the control information <NUM>, the second wireless device <NUM> relays <NUM> the first HARQ-ACK/NACK <NUM>, which was received from the first wireless device <NUM>, to the network node <NUM>.

The control information <NUM> may be provided to the second wireless device <NUM> by any means available, and preferably by the means presented in this disclosure. The first HARQ-ACK/NACK <NUM>, the HARQ-ACK/NACK <NUM> associated with the first transmission <NUM>, may be sent to the second wireless device <NUM> by any means available, and preferably by the means presented in this disclosure.

The first transmission <NUM> may be transmitted <NUM> in a relayed signal path from the network node <NUM> to the first wireless device <NUM>. In a preferred embodiment of the method <NUM>, the first transmission <NUM> is transmitted <NUM> directly from the network node <NUM> to the first wireless device <NUM>.

The final decision to actually relay <NUM> the first HARQ-ACK/NACK <NUM> by the second wireless device <NUM> may, as detailed elsewhere in this disclosure, be taken by e.g. the network node <NUM>, the first wireless device <NUM>, or the second wireless device <NUM>. If, for instance, the first wireless device takes the decision to relay <NUM> the first HARQ-ACK/NACK, or any HARQ-ACK/NACK for that matter, may be based on e.g. an UL channel quality of the first wireless device <NUM>, an UL channel resource availability of the first wireless device <NUM>, an UL channel capacity of the first wireless device <NUM>, and/or an urgency associated with the first HARQ-ACK/NACK <NUM> etc. Similarly, if the decision lies with the network node <NUM>, the criteria may comprise the same basis as those listed above, but preferably with the addition of the corresponding basis relating to the second wireless device <NUM>.

As explained, the teachings of this disclosure are workable also for relaying <NUM> HARQ-ACK/NACK information from more than one wireless device <NUM>, <NUM>. This means that the method <NUM> may further comprise the network node <NUM> transmitting <NUM> an additional transmission <NUM> to one of the one or more additional wireless devices <NUM> of the wireless communication network <NUM>. These additional wireless devices <NUM> are preferably configured to transmit <NUM> an additional HARQ-ACK/NACK <NUM> associated with the additional transmission <NUM>. As previously explained, based on the control information <NUM>, the second wireless device <NUM> relays <NUM> the first HARQ-ACK/NACK <NUM> together with the additional HARQ-ACK/NACK <NUM> to the network node <NUM>.

The method <NUM> may further comprise a second transmission <NUM> being transmitted <NUM> by the network node <NUM> to the second wireless device <NUM>. The second wireless device <NUM> may be configured to combine its own HARQ-ACK/NACK <NUM> associated with the second transmission <NUM> in the relaying <NUM> of other HARQ-ACK/NACK <NUM>, <NUM>.

In <FIG>, a schematic view of the first wireless device <NUM> according to one embodiment is shown. The first wireless device <NUM> comprises one or more controllers <NUM> which may be configured to, when the first wireless device <NUM> is operable in a wireless communication system <NUM>, perform the steps associated with first wireless device <NUM> of the method <NUM> according to this disclosure.

<FIG> illustrates another example implementation of the first wireless device <NUM>, which may be in the form of a UE. The first wireless device <NUM> comprises a processor <NUM>, a memory <NUM> and a communications interface <NUM> with transmission and reception capabilities. The memory <NUM> comprises instructions executable by the processor <NUM> whereby the first wireless device <NUM> is operative to, see e.g. <FIG>, receive the first transmission <NUM>, and responsive thereto, transmit <NUM> the first HARQ-ACK/NACK <NUM> to the second wireless device <NUM>. To this end, said memory <NUM> comprising instructions executable by the processor <NUM> whereby the first wireless device <NUM> is operative to perform the steps of the method <NUM> relating to the first wireless device <NUM> as described in conjunction with <FIG>.

<FIG> is a schematic view of a computer program product <NUM> according to one embodiment. The computer program product <NUM> comprises instructions which, when executed on at least one processor <NUM> or controller <NUM> of the first wireless device <NUM>, cause the at least one processor <NUM> or controller <NUM> to carry out the method <NUM> and/or any other features listed in this disclosure related to the first wireless device <NUM>.

In <FIG>, a schematic view of the second wireless device <NUM> according to one embodiment is shown. The second wireless device <NUM> comprises one or more controllers <NUM> which may be configured to, when the second wireless device <NUM> is operable in a wireless communication system <NUM>, perform the steps associated with second wireless device <NUM> of the method <NUM> according to this disclosure.

<FIG> illustrates another example implementation of the second wireless device <NUM>, which may be in the form of a UE. The second wireless device <NUM> comprises a processor <NUM>, a memory <NUM> and a communications interface <NUM> with transmission and reception capabilities. The memory <NUM> comprises instructions executable by the processor <NUM> whereby the second wireless device <NUM> is operative to, see e.g. <FIG>, receive the first HARQ-ACK/NACK <NUM>, and responsive to control information <NUM> to that effect, relay <NUM> the first HARQ-ACK/NACK <NUM> to the network node <NUM>. To this end, said memory <NUM> comprising instructions executable by the processor <NUM> whereby the second wireless device <NUM> is operative to perform the steps of the method <NUM> relating to the second wireless device <NUM> as described in conjunction with <FIG>.

<FIG> is a schematic view of a computer program product <NUM> according to one embodiment. The computer program product <NUM> comprises instructions which, when executed on at least one processor <NUM> or controller <NUM> of the second wireless device <NUM>, cause the at least one processor <NUM> or controller <NUM> to carry out the method <NUM> and/or any other features listed in this disclosure related to the second wireless device <NUM>.

In <FIG>, a schematic view of the additional wireless device <NUM> according to one embodiment is shown. The additional wireless device <NUM> comprises one or more controllers <NUM> which may be configured to, when the additional wireless device <NUM> is operable in a wireless communication system <NUM>, perform the steps associated with additional wireless device <NUM> of the method <NUM> according to this disclosure.

<FIG> illustrates another example implementation of the additional wireless device <NUM>, which may be in the form of a UE. The additional wireless device <NUM> comprises a processor <NUM>, a memory <NUM> and a communications interface <NUM> with transmission and reception capabilities. The memory <NUM> comprises instructions executable by the processor <NUM> whereby the additional wireless device <NUM> is operative to, see e.g. <FIG>, receive the additional transmission <NUM>, and responsive thereto, transmit <NUM> the additional HARQ-ACK/NACK <NUM> to the second wireless device <NUM>. To this end, said memory <NUM> comprising instructions executable by the processor <NUM> whereby the additional wireless device <NUM> is operative to perform the steps of the method <NUM> relating to the additional wireless device <NUM> as described in conjunction with <FIG>.

<FIG> is a schematic view of a computer program product <NUM> according to one embodiment. The computer program product <NUM> comprises instructions which, when executed on at least one processor <NUM> or controller <NUM> of the additional wireless device <NUM>, cause the at least one processor <NUM> or controller <NUM> to carry out the method <NUM> and/or any other features listed in this disclosure related to the additional wireless device <NUM>.

In <FIG>, a schematic view of the network node <NUM> according to one embodiment is shown. The network node <NUM> comprises one or more controllers <NUM> which may be configured to, when network node <NUM> is operable in a wireless communication system <NUM>, perform the steps associated with network node <NUM> of the method <NUM> according to this disclosure.

<FIG> illustrates another example implementation of the network node <NUM>, which may be in the form of a gNB. The network node <NUM> comprises a processor <NUM>, a memory <NUM> and a communications interface <NUM> with transmission and reception capabilities. The memory <NUM> comprises instructions executable by the processor <NUM> whereby the network node <NUM> is operative to, see e.g. <FIG>, transmit <NUM> the first transmission <NUM> to the first wireless device <NUM>, receive, in responsive thereto receive the first HARQ-ACK/NACK <NUM> relayed <NUM> by the second wireless device <NUM>. To this end, said memory <NUM> comprising instructions executable by the processor <NUM> whereby the additional wireless device <NUM> is operative to perform the steps of the method <NUM> relating to network node <NUM> as described in conjunction with <FIG>.

<FIG> is a schematic view of a computer program product <NUM> according to one embodiment. The computer program product <NUM> comprises instructions which, when executed on at least one processor <NUM> or controller <NUM> of the network node <NUM>, cause the at least one processor <NUM> or controller <NUM> to carry out the method <NUM> and/or any other features listed in this disclosure related to the network node <NUM>.

<FIG> is a schematic view of a carrier <NUM> according to one exemplary embodiment. The carrier <NUM> may be any one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium. In one further embodiment of the carrier <NUM>, the carrier <NUM> comprises the computer program product <NUM> for the first wireless device <NUM>. In an alternative embodiment of the carrier <NUM>, the carrier <NUM> comprises the computer program product <NUM> for the second wireless device <NUM>. In another alternative embodiment of the carrier <NUM>, the carrier <NUM> comprises the computer program product <NUM> for the additional wireless device <NUM>. In another alternative embodiment of the carrier <NUM>, the carrier <NUM> comprises the computer program product <NUM> for the network node <NUM>.

With reference to <FIG>, in accordance with an embodiment, a communication system, which may the wireless communication system <NUM>, includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 3212a, 3212b, 3212c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 3213a, 3213b, 3213c. Each base station 3212a, 3212b, 3212c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first user equipment (UE) <NUM> located in coverage area 3213c is configured to wirelessly connect to, or be paged by, the corresponding base station 3212c. A second UE <NUM> in coverage area 3213a is wirelessly connectable to the corresponding base station 3212a.

In a communication system <NUM>, which may be the wireless communication system <NUM>, a host computer <NUM> comprises hardware <NUM> including a communication interface <NUM> configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system <NUM>.

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, as previously explained, improve spectrum efficiency, reliability etc. and thereby provide benefits such as e.g. reduced user waiting time etc..

Claim 1:
A method (<NUM>) of transferring Hybrid Automatic Repeat Request, HARQ, positive Acknowledgement, ACK, or Negative Acknowledgement, NACK, in a wireless communication system (<NUM>) comprising a first wireless device (<NUM>), a second wireless device (<NUM>) and a network node (<NUM>), wherein the network node is a base station, the method (<NUM>) comprising:
transmitting (<NUM>), by the network node (<NUM>), a first transmission (<NUM>) directly to the first wireless device (<NUM>); in response thereto
determining, by the first wireless device, if a first HARQ-ACK/NACK (<NUM>) should be relayed by the second wireless device based on at least one of
an uplink, UL, channel quality of the first wireless device (<NUM>),
an UL channel resource availability of the first wireless device (<NUM>),
an UL channel capacity of the first wireless device (<NUM>), and/or
an urgency associated with the first HARQ-ACK/NACK (<NUM>);
transmitting (<NUM>), by the first wireless device (<NUM>) to the second wireless device (<NUM>), the first HARQ-ACK/NACK (<NUM>) associated with the first transmission (<NUM>); and
responsive to control information (<NUM>) provided to the second wireless device (<NUM>) indicating that the first HARQ-ACK/NACK (<NUM>) is to be forwarded to the network node (<NUM>):
relaying (<NUM>), by the second wireless device (<NUM>), the first HARQ-ACK/NACK (<NUM>) to the network node (<NUM>).