WO2018174766A1 - Systems and methods for harq feedback control when nr and lte co-exist on the same carrier - Google Patents

Abstract

Systems and methods are disclosed herein for configuring and using Transmit Time Interval (TTI) bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request (HARQ) in a first radio access network of a first Radio Access Technology (RAT) that in such a manner as to avoid conflicts with a second radio access network of a second RAT when sharing uplink and/or downlink resources on the same carrier. In some embodiments, a method of operation of a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT comprises configuring TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier.

Description

SYSTEMS AND METHODS FOR HARQ FEEDBACK CONTROL WHEN NR AND LTE CO-EXIST ON THE SAME CARRIER

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 62/476,283, filed March 24, 2017, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] New Radio (NR), Long Term Evolution (LTE), Hybrid Automatic Repeat Request (HARQ)

Background

[0003] New Radio (NR), which is also known as Fifth Generation (5G) or Next Generation, architecture is being discussed in Third Generation Partnership Project (3GPP). The current concept for the N R architecture is illustrated in Figure 1 , where enhanced or evolved Node B (eNB) denotes a Long Term Evolution (LTE) eNB, gNB denotes a NR base station where one NR base station may correspond to one or more transmission/reception points, and the lines between the nodes illustrate the corresponding interfaces which are under discussion in 3GPP. Further, Figure 2 illustrates deployment scenarios with NR base stations which are discussed in 3GPP.

[0004] Multi-antenna schemes for NR are currently being discussed in 3GPP. For NR, frequency ranges up to 100 gigahertz (GHz) are considered. It is known that high-frequency radio communication above 6 GHz suffers from significant path loss and penetration loss. One solution to address this issue is to deploy large-scale antenna arrays to achieve high beamforming gain, which is a reasonable solution due to the small wavelength of high-frequency signal.

Therefore, Multiple Input Multiple Output (MIMO) schemes for NR are also called massive MIMO. For around 30/70 GHz, up to 256 transmit (Tx) and receive (Rx) antenna elements are assumed. Extension to support 1024 Tx at 70 GHz is agreed and it is under discussion for 30 GHz. For sub-6 GHz communication, to obtain more beamforming and multiplexing gain by increasing the number of antenna elements is also a trend.

[0005] With massive MIMO, three approaches to beamforming have been discussed: analog, digital, and hybrid (a combination of the two). The analog beamforming would compensate high pathloss in NR scenarios, while digital precoding would provide additional performance gains similar to MIMO for sub-6 GHz necessary to achieve a reasonable coverage. The implementation complexity of analog beamforming is significantly less than digital precoding since in many implementations it relies on simple phase shifters, but the drawbacks are its limitation in multi-direction flexibility (i.e., a single beam can be formed at a time and the beams are then switched in the time domain), only wideband transmissions (i.e., not possible to transmit over a sub-band), unavoidable inaccuracies in the analog domain, etc. Digital beamforming (requiring costly converters to/from the digital domain from/to Intermediate Frequency (IF) domain), used today in LTE, provides the best performance in terms of data rate and multiplexing capabilities (multiple beams over multiple sub-bands at a time can be formed), but at the same time it is challenging in terms of power consumption, integration, and cost; in addition to that the gains do not scale linearly with the number of transmit/receive units while the cost is growing rapidly. Supporting hybrid beamforming, to benefit from cost-efficient analog beamforming and high-capacity digital beamforming, is therefore desirable for NR. An example diagram for hybrid beamforming is shown in Figure 3.

[0006] Beamforming can be on transmission beams and/or reception beams, network side or User Equipment device (UE) side.

[0007] The analog beam of a subarray can be steered toward a single direction on each Orthogonal Frequency Division Multiplexing (OFDM) symbol, and hence the number of subarrays determines the number of beam directions and the corresponding coverage on each OFDM symbol. However, the number of beams to cover the whole serving area is typically larger than the number of subarrays, especially when the individual beam width is narrow. Therefore, to cover the whole serving area, multiple transmissions with narrow beams differently steered in the time domain are also likely to be needed. The provision of multiple narrow coverage beams for this purpose has been called "beam sweeping" (see, e.g., Figures 4A and 4B). For analog and hybrid beamforming, the beam sweeping seems to be essential to provide the basic coverage in NR. For this purpose, multiple OFDM symbols, in which differently steered beams can be transmitted through subarrays, can be assigned and periodically transmitted.

[0008] For LTE, the term "numerology" includes, e.g., the following elements: frame duration, subframe or Transmit Time Interval (TTI) duration, slot duration, subcarrier spacing, Cyclic Prefix (CP) length, number of subcarriers per

Resource Block (RB), number of RBs within the bandwidth (different

numerologies may result in different numbers of RBs within the same bandwidth), number of symbols within a certain time unit, e.g., 1 millisecond (ms) subframe, symbol length, etc.

[0009] The exact values for the numerology elements in different Radio Access Technologies (RATs) are typically driven by performance targets, e.g., performance requirements impose constraints on usable subcarrier spacing sizes, e.g., the maximum acceptable phase noise sets the minimum subcarrier bandwidth while the slow decay of the spectrum (impacting filtering complexity and guardband sizes) favors smaller subcarrier bandwidth for a given carrier frequency, and the required CP sets the maximum subcarrier bandwidth for a given carrier frequency to keep overhead low.

[0010] However, the numerology used so far in the existing RATs is rather static and typically can be trivially derived by the UE, e.g., by one-to-one mapping to RAT, frequency band, service type (e.g., Multimedia

Broadcast/Multicast Service (MBMS)), etc.

[0011] In LTE downlink which is OFDM-based, the subcarrier spacing is 15 kilohertz (kHz) for normal CP and 15 kHz and 7.5 kHz (i.e., the reduced carrier spacing) for extended CP, where the latter is allowed only for MBMS-dedicated carriers. [0012] The support of multiple numerologies has been agreed for NR, which can be multiplexed in the frequency and/or time domain for the same or different UEs.

[0013] In NR which is to be based on OFDM, multiple numerologies will be supported for general operation. A scaling approach (based on a scaling factor 2^Λη, n G N₀) is considered for deriving subcarrier spacing candidates for NR. Values for subcarrier bandwidths currently discussed include, among others, 3.75 kHz, 15 kHz, 30 kHz, and 60 kHz. The numerology-specific slot durations can then be determined in ms based on the subcarrier spacing: subcarrier spacing of (2^m*15) kHz gives exactly 1 /2^m 0.5 ms for a slot that is 0.5 ms in the 15 kHz numerology.

[0014] Subcarrier spacings of at least up to 480 kHz are currently being discussed for NR (the highest discussed values correspond to millimeter-wave based technologies). It was also agreed that multiplexing different numerologies within a same NR carrier bandwidth is supported, and Frequency Domain

Multiplexing (FDM) and/or Time Domain Multiplexing (TDM) can be considered. It was further agreed that multiple frequency/time portions using different numerologies share a synchronization signal, where the synchronization signal refers to the signal itself and the time-frequency resource used to transmit the synchronization signal. Yet another agreement is that the numerology used can be selected independently of the frequency band although it is assumed that a very low subcarrier spacing will not be used at very high carrier frequencies. In Figure 5, some candidate carrier spacings are illustrated with respect to the frequency and cell range. In Table 1 , further details are provided on

corresponding time durations for some candidate carrier spacings.

Table 1 : Different OFDM numerologies

[0015] Evolved Universal Terrestrial Radio Access Network (E-UTRAN) provides Automatic Repeat Request (ARQ) and Hybrid ARQ (HARQ)

functionalities for transmission error correction. The ARQ functionality provides error correction by retransmissions in acknowledged mode at Layer 2. HARQ is an N-process Stop-And-Wait, and it transmits and retransmits transport blocks. Upon reception of a transport block, the receiver makes an attempt to decode the transport block and informs the transmitter about the outcome of the decoding operation through a single Acknowledgement/Negative Acknowledgement (ACK/NACK) bit indicating whether the decoding was successful or if a retransmission of the transport block is required.

[0016] The HARQ functionality ensures delivery between peer entities at Layer 1 , and independent HARQ processes are used for downlink and uplink transmission delivery per cell. In a Carrier Aggregation (CA) system, where multiple serving cells may be configured, HARQ is defined per serving cell.

HARQ is supported for the Downlink Shared Channel (DL-SCH) and Uplink Shared Channel (UL-SCH) transport channels transmitted in Physical Downlink Shared Channel (PDSCH) and Physical Uplink Shared Channel (PUSCH) physical channels, respectively, e.g.:

• HARQ may be used for dynamically scheduled downlink and/or uplink transmissions. A UE always monitors the Physical Downlink Control Channel(s) (PDCCH(s)) to find possible allocations for downlink and/or uplink.

· HARQ may be used for semi-persistently allocated downlink and/or uplink transmissions. PDCCH indicates whether the downlink/uplink grant is a semi-persistent one, i.e., whether it can be implicitly reused in the following TTIs according to the periodicity defined by Radio Resource Control (RRC). When required, retransmissions are explicitly signaled via the PDCCH(s). In the subframes where the UE has semi-persistent downlink/uplink resources, if the UE cannot find its Cell Radio Network Temporary Identifier (C-RNTI) on the PDCCH(s), a downlink/uplink transmission according to the semi-persistent allocation that the UE has been assigned in the TTI is assumed. Otherwise, the PDCCH allocation overrides the semi-persistent allocation for that TTI.

• HARQ is used for contention-based Random Access (RA) transmissions, both for the first scheduled uplink transmission (e.g., for initial access, after handover, or RRC connection reestablishment) and for contention resolution in downlink (where HARQ feedback is transmitted only by the UE which detects its own UE identity, as provided in message 3, echoed in the Contention Resolution message). HARQ failure in the first uplink transmission step or in the contention resolution step may result, e.g., in a

C-RNTI detection failure by the UE or erroneous assignment of the same C-RNTI also to another UE.

[0017] ACK/NACK feedback is used, e.g., in LTE, by the intended receiving node to inform a transmitting node that its transmission has been or has not been successfully received. The ACK/NACKs may be transmitted in response to downlink or uplink transmissions by the UE (via uplink control channel or data channel) or eNB (via Physical HARQ Indicator Channel (PHICH)), respectively. For the HARQ feedback transmitted by the UE in uplink, in general, it is expected that in Frequency Division Duplexing (FDD) the UE transmits the feedback in subframe (n+4) for the downlink reception in subframe n. For Time Division Duplexing (TDD), the relation is also predefined but depends on the TDD configuration. In Half Duplex FDD (HD-FDD), the timing relation between reception of data at the UE and transmission of HARQ A/N in the uplink is also predefined, e.g., in Narrowband Internet of Things (NB-loT) the ACK/NACK is sent in subframe n+12. [0018] Asynchronous adaptive HARQ is used for DL-SCH transmission (see Figure 6A), implying asynchronous retransmissions and synchronous HARQ feedback. Uplink ACK NACKs in response to downlink (re)transmissions are sent on Physical Uplink Control Channel (PUCCH) or PUSCH.

[0019] PDCCH signals the HARQ process number and also indicates if it is a transmission or retransmission. Retransmissions are always scheduled through PDCCH.

[0020] Synchronous HARQ is used for UL-SCH transmission, implying synchronous retransmissions and synchronous HARQ feedback, i.e., the time instant for the retransmissions is fixed once the initial transmission has been scheduled and known to both UE and eNB (see Figure 6B) and hence no need to signal HARQ process number. The maximum number of retransmissions is configured per UE. Downlink ACK/NACKs in response to uplink

(re)transmissions are sent on PHICH. HARQ operation in uplink is summarized in Table 2 below.

[0021] To improve uplink coverage for cell edge UEs at a lower delay and reduce the HARQ failure probability (e.g., by reducing HARQ signaling), TTI bundling may be used, by which multiple HARQ transmission attempts in consecutive TTIs before receiving HARQ feedback may be configured. An example is illustrated in Figure 6C, where a bundle comprises sending four Redundancy Versions (RVs) in four consecutive TTIs. Note that compared to Figure 6B, the retransmission of the bundle is delayed, which is because the shortest HARQ Round Trip Time (RTT) with the bundle of size of 4 is 1 1 ms which cannot be synchronized with the normal HARQ RTT of 8 ms and thus a period of 16 ms should be configured. The time slots in between can be used for some other bundled HARQ processes from the given UE or other UEs using TTI bundling.

[0022] Currently, TTI bundling support may not be supported for all UEs (it is UE capability); TTI bundling may be configured for FDD and for TDD only for configurations 0, 1 , and 6. PDCCH

HARQ feedback

detected/seen by UE behavior seen by the UE

the UE

ACK or NACK New Transmission New transmission according to PDCCH

Retransmission according to PDCCH (adaptive

ACK or NACK Retransmission

retransmission)

No (re)transmission, keep data in HARQ buffer and

ACK None

a PDCCH is required to resume retransmissions

NACK None Non-adaptive retransmission

Table 2. UL HARQ operation

[0023] At least the following problems are envisioned. In the NR Work Item Description (WID) [NTT DOCOMO, INC. , "RP-1 70847: New WID on New Radio Access Technology," 3GPP TSG RAN Meeting #75, March 6-9, 2017], the following is stated among the objectives:

NR-LTE co-existence mechanisms [RAN1 , RAN 2, RAN4]: Support co-existence of LTE UL and NR UL within the bandwidth of an LTE component carrier and co-existence of LTE DL and NR DL within the bandwidth of an LTE component carrier, and identify and specify at least one NR band/LTE-NR band combination for this operation.

However, currently there are no methods to enable the objective below.

Furthermore, there are certain dependencies between downlink and uplink which may limit the system flexibility requested above or even make it not possible.

Summary

[0024] Systems and methods are disclosed herein for configuring and using Transmit Time Interval (TTI) bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request (HARQ) in a first radio access network of a first Radio Access Technology (RAT) that in such a manner as to avoid conflicts with a second radio access network of a second RAT when sharing uplink and/or downlink resources on the same carrier. In some embodiments, a method of operation of a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT comprises configuring TTI

bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier.

[0025] In some embodiments, the method further comprises using TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network in accordance with a result of configuring TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network.

[0026] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT adaptively based on a subset of time and/or frequency resources allocated for downlink transmissions for the second RAT such that downlink transmissions of the first RAT for a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources allocated for downlink transmissions for the second RAT.

[0027] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier, wherein uplink transmissions in the first radio access network of the first RAT and downlink transmissions in the first radio access network of the first RAT are related in time.

[0028] In some embodiments, the first RAT is Long Term Evolution (LTE) and the second RAT is New Radio (NR), and configuring uplink TTI

bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for NR downlink transmissions in the second radio access network such that LTE downlink transmissions of a given channel are avoided in resources which are comprised in the subset. In some embodiments, the given channel is a Physical HARQ Indicator Channel (PHICH) with uplink HARQ feedback.

[0029] In some embodiments, the first RAT is NR and the second RAT is LTE, and configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for LTE downlink transmissions in the second radio access network such that NR downlink transmissions of a given channel are avoided in resources which are comprised in the subset. In some

embodiments, the given channel is a data channel, a control channel, or a channel with uplink HARQ feedback.

[0030] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT such that at least one parameter of TTI bundling/aggregation and/or HARQ configuration is based on at least one parameter characterizing resources associated with the second RAT. In some embodiments, the at least one parameter of TTI bundling/aggregation and/or HARQ configuration comprises bundle size, bundle transmission time and resources, transmission power, and/or number of HARQ retransmissions. In some embodiments, the at least one parameter characterizing resources associated with the second RAT comprises time, pattern, numerology, and/or duplex mode for the resources associated with the second RAT. [0031] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises adapting an uplink TTI size for the first radio access network of the first RAT such that downlink transmission for the first RAT are avoided in resources associated with the second RAT.

[0032] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring a first transmission and/or transmitting a scheduling grant in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for downlink transmissions in the second radio access network.

[0033] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring use of synchronous or asynchronous uplink HARQ in the first radio access network of the first RAT based on one or more triggering conditions related to the second RAT.

[0034] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring asynchronous uplink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT is avoided. In some

embodiments, configuring asynchronous uplink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT are avoided comprises selecting asynchronous uplink HARQ for use in the first radio access network of the first RAT if the first radio access network and the second radio access network share the same downlink carrier frequency. In some

embodiments, configuring asynchronous uplink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT are avoided comprises scheduling asynchronous uplink HARQ feedback and/or a transmission that triggers asynchronous uplink HARQ feedback such that the asynchronous uplink HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first RAT. In some embodiments, the first RAT is LTE and the second RAT is NR. In some embodiments, the first RAT is NR and the second RAT is LTE.

[0035] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT adaptively based on a subset of time and/or frequency resources allocated for uplink transmissions in the second RAT such that uplink

transmissions in the first radio access network of the first RAT for a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources allocated for uplink transmissions in the second RAT.

[0036] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier.

[0037] In some embodiments, the first RAT is LTE and the second RAT is N R, and configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier comprises configuring downlink TTI

bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for NR uplink

transmissions in the second radio access network such that LTE uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0038] In some embodiments, the first RAT is NR and the second RAT is LTE, and configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier comprises configuring downlink TTI

bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for LTE uplink transmissions in the second radio access network such that NR uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0039] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring use of synchronous or asynchronous downlink HARQ in the first radio access network of the first RAT based on one or more triggering conditions related to the second RAT.

[0040] In some embodiments, configuring TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring asynchronous downlink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided. In some embodiments, configuring asynchronous downlink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided comprises selecting asynchronous downlink HARQ for use in the first radio access network of the first RAT if the first radio access network and the second radio access network share the same uplink carrier frequency. In some embodiments, configuring asynchronous downlink HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided comprises scheduling asynchronous downlink HARQ feedback and/or a transmission that triggers asynchronous HARQ feedback such that the asynchronous downlink HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first RAT. In some embodiments, the first RAT is LTE and the second RAT is NR. In some embodiments, the first RAT is NR and the second RAT is LTE.

[0041] In some embodiments, the node is a network node. In some embodiments, the node is a wireless device.

[0042] Embodiments of a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT are also disclosed. In some embodiments, a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT is adapted to configure TTI

bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier.

[0043] In some embodiments, a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT comprises at least one processor and memory comprising instructions executable by the at least one processor whereby the node is operable to configure TTI

bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier.

[0044] In some embodiments, a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT comprises a configuring module operable to configure TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier. Brief Description of the Drawings

[0045] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0046] Figure 1 illustrates an example architecture for a Third Generation Partnership Project (3GPP) New Radio (NR) network;

[0047] Figure 2 illustrates example deployments of a NR network;

[0048] Figure 3 illustrates one example of hybrid beamforming;

[0049] Figures 4A and 4B illustrates examples of transmit beam sweeping;

[0050] Figure 5 illustrates examples of candidate carrier spacings;

[0051] Figures 6A through 6C illustrate Long Term Evolution (LTE) Hybrid Automatic Repeat Request (HARQ);

[0052] Figure 7 is a flow chart that illustrates the operation of a node according to some embodiments of the present disclosure;

[0053] Figure 8 illustrates one example of a wireless system (e.g., a cellular communications network such as, e.g., a 3GPP Fifth Generation (5G) or N R network), in which embodiments of the present disclosure may be implemented;

[0054] Figures 9 and 1 0 are example embodiments of a wireless device; and

[0055] Figures 1 1 through 13 are example embodiments of a network node.

Detailed Description

[0056] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0057] In some embodiments a non-limiting term "User Equipment" or "UE" is used. The UE herein can be any type of wireless device capable of communicating with network node or another UE over radio signals. The UE may also be a radio communication device, a target device, a Device-to-Device (D2D) UE, a machine type UE or a UE capable of Machine-to-Machine (M2M) communication, a sensor equipped with a UE, an iPad, a tablet, mobile terminals, a smart phone, Laptop Embedded Equipment (LEE), Laptop

Mounted Equipment (LME), Universal Serial Bus (USB) dongles, Customer Premises Equipment (CPE), etc.

[0058] Also in some embodiments generic terminology "network node" is used. It can be any kind of network node which may comprise a radio network node such as a base station, a radio base station, a base transceiver station, a base station controller, a network controller, a New Radio (NR) base station (gNB), a NR base station, an enhanced or evolved Node B (eNB), a Node B, a Multi-Cell/Multicast Coordination Entity (MCE), a relay node, an access point, a radio access point, a Remote Radio Unit (RRU) , a Remote Radio Head (RRH), a multi-standard base station (aka a Multi-Standard Radio (MSR) base station), a core network node (e.g., a Mobility Management Entity (MME), a Self- Organizing Network (SON) node, a coordinating node, a positioning node, a Minimization of Drive Tests (MDT) node, etc.), or even an external node (e.g., a third party node, a node external to the current network), test or trial equipment (e.g., a field test or a laboratory test), etc. The network node may also comprise test equipment.

[0059] The term Long Term Evolution (LTE) used herein may also comprise enhanced LTE.

[0060] The term "radio node" used herein may be used to denote a UE or a radio network node.

[0061] The embodiments are applicable to single carrier as well as to multicarrier or Carrier Aggregation (CA) operation of the UE in which the UE is able to receive and/or transmit data to more than one serving cells. The term CA is also called (e.g. , interchangeably called) "multi-carrier system," "multi-cell operation," "multi-carrier operation," and "multi-carrier" transm ission and/or reception. In CA one of the Component Carriers (CCs) is the Primary

Component Carrier (PCC) or simply primary carrier or even anchor carrier. The remaining ones are called Secondary Component Carriers (SCCs) or simply secondary carriers or even supplementary carriers. The serving cell is interchangeably called a Primary Cell (PCell) or a Primary Serving Cell (PSC). Similarly, the secondary serving cell is interchangeably called a Secondary Cell (SCell) or Secondary Serving Cell (SSC).

[0062] The term "signaling" used herein may comprise any of: high-layer signaling (e.g., via Radio Resource Control (RRC) or the like), lower-layer signaling (e.g., via a physical control channel or a broadcast channel), or a combination thereof. The signaling may be implicit or explicit. The signaling may further be unicast, multicast, or broadcast. The signaling may also be directly to another node or via a third node.

[0063] The term "time resource" used herein may correspond to any type of physical resource or radio resource expressed in terms of length of time.

Examples of time resources are: symbol, time slot, subframe, radio frame, Transmit Time Interval (TTI), interleaving time, etc.

[0064] The term "radio measurement" used herein may refer to any measurement performed on radio signals. Radio measurements can be absolute or relative. Radio measurements can be, e.g., intra-frequency, inter-frequency, CA, etc. Radio measurements can be unidirectional (e.g., downlink or uplink) or bidirectional (e.g., Round Trip Time (RTT), receive-transmit (Rx-Tx), etc.). Some examples of radio measurements: timing measurements (e.g., Time of Arrival (TOA), timing advance, RTT, Reference Signal Time Difference (RSTD), System Frame Number and Subframe Timing Difference (SSTD), Rx-Tx, propagation delay, etc.), angle measurements (e.g., angle of arrival), power-based

measurements (e.g., received signal power, Reference Signal Received Power (RSRP), received signal quality, Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR), interference power, total interference plus noise, Received Signal Strength Indicator (RSSI), noise power, Channel Quality Indication (CQI), Channel State Information (CSI), Precoding Matrix Indicator (PMI), etc.), cell detection or cell identification, beam detection or beam identification, Radio Link Monitoring (RLM), system information reading, etc.

[0065] The term "beamformed measurement," which is also known as radio beamformed measurement, used herein refers to any of the above radio measurements performed by a radio node on at least radio signals, which are transmitted by another radio node using at least one beam. The transmitted beam may be created by at least two transmit antennas or antenna elements. The beamformed measurement is also interchangeably called a 'measurement with beamforming,' a measurement on one or more beams, a beam

measurement, etc. The term beamformed measurement may further comprise performing the measurement using beamformed reception, i.e., using at least one reception beam. The beamformed measurement performed without measurement on the reception beam is denoted by Nb1 . The beamformed measurement performed with the reception beam is denoted by Nb2. For consistency, a beamformed measurement is denoted by a generic term, 'Nb,' and it can be Nb1 or Nb2.

[0066] The term "non-beamformed measurement," which is also known as radio non-beamformed measurement, used herein refers to any of the above radio measurements performed by a radio node on at least radio signals, which are transmitted by another radio node without any beam. The radio signal may be transmitted from the other radio node by using one or more transmit antennas. The radio signals are transmitted in the entire cell or at least in the part of the signal, e.g., in the sector. The non-beamformed measurement is also interchangeably called a 'measurement without beamforming,' a measurement on omnidirectional signals or signals transmitted from omnidirectional or sectorized but not beamforming antennas, an omnidirectional measurement, a sector measurement, etc. The term non-beamformed measurement may further comprise performing the measurement using non-beamformed reception, i.e., without using any reception beam. The non-beamformed measurement performed without reception beam is denoted by Nn1 . The term non- beamformed measurement may further comprise performing the measurement using beamformed reception, i.e., using at least one reception beam. The non- beamformed measurement performed with the reception beam is denoted by Nn2. For consistency, a non-beamformed measurement with or without reception beam is denoted by a generic notation, 'Nn,' and it can be Nn1 or Nn2.

[0067] The term "measurement performance" used herein may refer to any criteria or metric which characterizes the performance of the measurement performed by a radio node. The term measurement performance is also called measurement requirement, measurement performance requirements, etc. The radio node has to meet one or more measurement performance criteria related to the performed measurement. Examples of measurement performance criteria are measurement time, number of cells to be measured with the measurement time, measurement reporting delay, measurement accuracy, measurement accuracy with regard to a reference value (e.g., ideal measurement result), etc. Examples of measurement time are measurement period, cell identification period, evaluation period, etc.

[0068] The term "dynamic (e.g., in time) antenna configuration" may comprise:

• The dynamic antenna configuration relates to beamforming and may

comprise beam switching or beam sweeping in the time domain (which may be used interchangeably herein in some embodiments).

· The dynamic antenna configuration may be at the first radio node side or at the second and/or third radio node sides.

• The dynamic configuration may apply to receive antennas and/or transmit antennas.

[0069] The term "numerology" used herein may refer, e.g. , to any one or more of: subcarrier spacing, number of subcarriers per Resource Block (RB), Cyclic

Prefix (CP) length, number of RBs within the bandwidth, subframe length, etc.

The numerology may be configured statically or change dynamically for transmissions from the same Transmission Point (TP) or cell and may or may not be the same for different cells and/or carrier frequencies.

[0070] The term "ΤΤ may also be interchangeably used herein with the term

"time unit" which may further comprise symbol, slot, minislot, subframe, etc. [0071] At least the following embodiments are described herein. In a first embodiment, uplink TTI bundling/aggregation is configured and used in RATI adaptively to (i.e., configured and used in RATI adaptively based on) a subset of time and/or frequency resources allocated for RAT2 downlink transmissions, so that RATI downlink transmissions of a given channel (e.g., Physical Hybrid Automatic Repeat Request (HARQ) Indicator Channel (PHICH) or more specifically PHICH with uplink HARQ feedback or similar) are avoided in resources which are comprised in the subset.

[0072] In a second embodiment, the selection or use of synchronous or asynchronous uplink HARQ in RATI is based on one or more triggering conditions related to RAT2, e.g. asynchronous uplink HARQ is used when RATI and RAT2 are sharing a downlink carrier frequency otherwise synchronous uplink HARQ may be used, or when predefined time instances for uplink HARQ feedback do not match (e.g., not a subset of) the downlink resources available for RATI (i.e., fall into the subset of time and/or frequency resources allocated for RAT2 downlink), etc.

[0073] In a third embodiment, downlink TTI bundling/aggregation is configured and used in RATI adaptively to (i.e., configured and used in RATI adaptively based on) a subset of time and/or frequency resources allocated for RAT2 uplink transmissions, so that RATI uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0074] In a fourth embodiment, the selection or use of synchronous or asynchronous downlink HARQ in RATI is based on one or more triggering conditions related to RAT2, e.g. asynchronous uplink HARQ is used when RATI and RAT2 are sharing an uplink carrier frequency otherwise synchronous downlink HARQ may be used, or when predefined time instances for downlink HARQ feedback do not match (e.g., not a subset of) the uplink resources available for RATI (i.e., fall into the subset of time and/or frequency resources allocated for RAT2 uplink), etc.

[0075] In all the above embodiments, RATI and RAT2 share resources on the same carrier for at least one of downlink and uplink. [0076] RATI may be LTE (or enhanced LTE), while RAT2 may be NR. RATI may be NR, while RAT2 may be LTE (or enhanced LTE).

[0077] In one example, RATI and RAT2 may be operated by the same network node. In another example, RATI and RAT2 may be operated by different network nodes.

[0078] In yet another example, a RATI network node and a RAT2 network node may be or may intend to be in dual carrier operation (i.e., both serving the UE, one as master eNB and another one as a secondary eNB, which physically may or may not be in the same node).

[0079] In one non-limiting example, RAT2 downlink resources may comprise a subset of the time resources configurable as Multicast- Broadcast Single Frequency Network (MBSFN) subframes, e.g., RAT2 downlink may not appear in subframe #0 or #5.

[0080] More generally, the HARQ operation of RATI is adapted to or configured based on how the downlink and/or uplink resources are shared on the same carrier with RAT2, where one of RATI and RAT2 is LTE and another one is NR. The HARQ configuration, determined based on the described

embodiments, may further be indicated to another node (e.g., base station (eNB or gNB) to UE, UE to base station (eNB or gNB), BS1 (eNB or gNB) to BS2 (eNB or gNB), network node 1 to network node 2). To facilitate such HARQ operation, there may also be coordination or message exchange or information delivery between eNB and gNB or UE and base station (eNB or gNB) regarding the shared downlink and/or uplink resource allocation and/or the allocation may be determined based on common rules known to both nodes. A UE operating to any embodiments described herein may further signal its capability to another node such as a network node. The UE and/or network node (operating RATI ) may also need to know the resources of RAT2. In one example, the network node may schedule resources in RAT2 and thus jointly control RATI HARQ operation and RAT2 resources. In another example, the network node may get the RAT2 resource information from a RAT2 network node. In another example, the UE may determine the RAT2 resources based on a predefined rule or standard and/or message from the RATI and/or RAT2 network node. The RATI network node may also use predefined rules to determine RAT2 resources. The UE or RATI network node may also determine RAT2 resources based on measurements and searching for a known signal associated with RAT2 or for a certain power profile.

[0081] Examples of HARQ operation include: scheduling/controlling resources for/performing a transmission which is in turn triggering Acknowledgment/ Negative Acknowledgment (ACK/NACK) transmission, receiving ACK/NACK, scheduling/controlling resources for/performing/bundling ACK/NACK

transmissions, etc.

[0082] The described embodiments provide advantages such as, e.g., the possibility to avoid conflicting resource allocation and hereby enable the system operation when LTE and NR share a carrier frequency.

[0083] Figure 7 is a flow chart that illustrates the operation of a node according to some embodiments of the present disclosure. The node may be a network node (e.g., a radio access node or a core network node) or a wireless device (e.g., a UE), depending on the particular embodiment. The node is associated with a wireless system, which may be referred to herein as a cellular network, that includes two (or more) Radio Access Technologies (RATs) (e.g., LTE and NR). Specifically, the wireless system includes a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT. In some embodiments, one of the two RATs is LTE (e.g., LTE-Advanced, LTE-Pro, or some enhanced version of LTE), and the other RAT is NR. In some embodiments, the two RATs share at least some downlink resources on the same downlink carrier and/or share at least some uplink resources on the same uplink carrier.

[0084] In this context, as discussed below in detail, the node configures TTI bundling (or TTI aggregation) and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict (i.e., overlap in time on the same resources on the same carrier) between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier (step 100). Optionally, the node uses TTI bundling (or TTI aggregation) and/or asynchronous HARQ in the first radio access network in accordance with a result of step 100 (step 102). Note that TTI bundling or TTI aggregation is denoted herein as TTI bundling/aggregation.

[0085] Various embodiments of configuring TTI bundling/aggregation or asynchronous HARQ such that conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier are described below. While discussed separately, the various embodiments may be used together in any desired combination.

Using Uplink TTI Bundling/Aggregation in RATI to Avoid Conflict with Downlink

Resources of RAT2

[0086] According to this embodiment, uplink TTI bundling/aggregation is used in the first RAT (RATI ) to avoid conflict with downlink resources of the second RAT (RAT2) when RATI and RAT2 are sharing downlink resources on the same carrier frequency, and where the uplink transmissions of RATI and downlink transmissions of RATI are related in time. In other words, with respect to Figure 7, the node configures uplink TTI bundling/aggregation in RATI to avoid conflict with downlink resources of RAT2 when RATI and RAT2 are sharing downlink resources on the same carrier frequency, where uplink transmissions of RATI and downlink transmission of RATI are related in time. In other words, the node configures uplink TTI bundling/aggregation in RATI to avoid conflict (i.e., overlap in time) between downlink resources used for HARQ feedback associated with the uplink TTI bundling/aggregation for RATI and downlink resources (on the same carrier) allocated for downlink transmissions for RAT2. For example, this embodiment may be used when RATI has downlink in a first subset of resources on carrier frequency f 1 and RAT2 has downlink in a second subset of resources on f1 , where the non-overlapping first and the second subsets of resources can be configured statically, semi-statically, or dynamically. The first subset and the second subset of resources may be used by a first set of UEs and a second set of UEs, wherein the first and the second sets of UEs may or may not overlap. [0087] In order to configure uplink TTI bundling/aggregation in RATI in accordance with this embodiment, the node may need to determine the downlink resources used by RAT2. The determining of RAT2 downlink resources may be based, e.g., on a message from another node, measurements, standard, and/or predefined rule. Also, a node capable of receiving/understanding signals of RAT2 may also determine whether resources are used by RAT2 transmissions by performing measurements in those resources or searching for known signals associated with RAT2 or determining a certain power profile.

[0088] In a further embodiment, at least one parameter of the UE TTI bundling and/or HARQ configuration (e.g., bundle size, bundle transmission time and resources, transmission power, number of HARQ retransmissions, etc.) may be based on at least one parameter (e.g., time, pattern, numerology, duplex mode, etc.) characterizing the resources associated with RAT2. In other words, when configuring the UE TTI bundling and/or HARQ configuration (e.g., in step 100 of Figure 7), the node may make this configuration based on at least one parameter (e.g., time, pattern, numerology, duplex mode, etc.) characterizing the resources associated with RAT2. For example, the maximum number of HARQ

transmissions may be reduced when TTI bundling is used according to the basic embodiment. In another example, the RATI uplink bundle transmission time or the grant (sent in RATI downlink) for this RATI uplink transmission may be selected or delayed so that the next downlink transmission is avoided to appear in resources allocated to RAT2. In another example, the bundle size may be optimized (e.g., depend on), e.g., for each uplink-downlink subframe

configuration (currently, the bundle size is four and TTI bundling cannot be used for some uplink-downlink subframe configuration).

[0089] In yet a further embodiment, the uplink TTI size may also be adapted to avoid the downlink transmissions of RATI in the resources associated with RAT2.

[0090] In one example, RATI is in LTE and RAT2 is NR, and LTE uplink TTI bundling is configured and used adaptively to a subset of time and/or frequency resources allocated for N R downlink transmissions, so that LTE downlink transmissions of a given channel (e.g., PH ICH or more specifically PHICH with uplink HARQ feedback) are avoided in resources which are comprised in the subset. In one example, the N R downlink resources may comprise any subframe except subframes #0 and #5. In another example, the NR downlink resources may comprise any subframe which may be configured as a LTE MBSFN subframe.

[0091] In another example, RATI is NR and RAT 2 is LTE, and NR uplink TTI bundling is configured and used adaptively to a subset of time and/or frequency resources allocated for LTE downlink transmissions, so that NR downlink transmissions of a given channel (e.g., control channel or data channel or more specifically channel with uplink HARQ feedback) are avoided in resources which are comprised in the subset.

[0092] The TTI bundling may concern one or more UEs. The size of the TTI bundle may be four TTIs.

[0093] In one example, controlling the uplink TTI bundling may be performed by a network node and indicated to the UE. In another example, controlling the uplink TTI bundling may be performed by a UE, e.g., based on a predefined rule and/or a message received from another node (e.g., a network node).

[0094] The adaptation/configuration may be in the UE (e.g., based on a predefined rule or a control message from the network node) and/or network node. The network node (operating RATI ) may also send a message or coordinate with another network node (operating RAT2).

[0095] The network node may need to configure/adapt the ACK/NACK transmission based on the above, e.g., for the uplink TTI bundle.

[0096] The UE may need to configure/adapt the reception of ACK/NACK transmitted by the network node.

[0097] The UE may need to configure/adapt the transmission (to be

ACK/NACK-ed) based on the above.

[0098] The network node may need to adapt/configure the reception of the uplink transmission (to be ACK/NACK-ed) based on the above. [0099] The downlink transmission of RATI and/or RAT2 may be based, e.g., on Frequency Division Duplexing (FDD), Time Division Duplexing (TDD), Half Duplex FDD (HD-FDD), or flexible duplex mode. RATI and RAT2 downlink transmissions may or may not have the same duplex.

[0100] In a further example, a node controlling uplink TTI bundling may coordinate with the node controlling NR downlink resources, e.g., one or more messages may be sent in one or both directions. The message(s) may comprise one or more parameters related to how RATI uplink TTI bundling is configured based on (to avoid the conflict with) the subset of RAT2 downlink resources. The node controlling RATI resources and the node controlling RAT2 resources may be different physical nodes or may be logical nodes (comprised in the same or different physical nodes). Furthermore, the messages between the two nodes may be sent via cross-layer communication, via a direct radio or non-radio interface, or even via a third node.

[0101] In yet another embodiment, the node may further configure the first transmission and/or transmit the scheduling grant adaptively to the set of RAT2 resources, e.g., to avoid sending RATI uplink scheduling grant in subframes when the next RATI PHICH ACK/NACK (in 8 milliseconds (ms)) cannot be received due to a conflict with RAT2 downlink resources.

[0102] Currently, TTI bundling can be used for data transmissions but not for Msg3 for Random Access (RA). It is thus an embodiment that TTI bundling may be used also for RA Msg3 when RATI and RAT2 are sharing downlink resources on the same carrier frequency. Selecting Asynchronous HARQ in RATI to Avoid the Conflict with RAT2

Downlink Resources

[0103] In this embodiment, asynchronous HARQ may be configured in RATI to avoid the conflict with RAT2 downlink resources. In other words, in step 1 00 of Figure 7, the node configures asynchronous HARQ in RATI to avoid conflict with RAT2 downlink resources, where RATI and RAT2 are sharing the same downlink carrier frequency. [0104] In this embodiment, the selection or use of synchronous or asynchronous uplink HARQ in RATI may further be based on one or more triggering conditions related to RAT2, e.g., asynchronous uplink HARQ is used when RATI and RAT2 are sharing a downlink carrier frequency, otherwise synchronous uplink HARQ may be used, or when predefined time instances for uplink HARQ feedback do not match (e.g., not a subset of) the downlink resources available for RATI (i.e., fall into the subset of time and/or frequency resources allocated for RAT2 downlink), etc. The selection may be based on a predefined rule or may be configurable, e.g., allowed or not allowed.

[0105] In a further embodiment, the selection of synchronous or

asynchronous HARQ operation may further comprise scheduling the feedback and/or the transmission which triggers the feedback so that the feedback can be transmitted in the resources which are determined to be available for RATI .

[0106] In one example, RATI and RAT2 are LTE and NR, respectively. In another example, RATI and RAT2 are NR and LTE, respectively.

[0107] The selection between synchronous and asynchronous uplink HARQ may be done in the UE (e.g., based on a predefined rule and/or message from another node) and/or controlled by a network node.

[0108] The adaptation/configuration may be in the UE (e.g., based on a predefined rule or a control message from the network node) and/or network node. The network node (operating RATI ) may also send a message or coordinate with another network node (operating RAT2).

[0109] The network node may need to configure/adapt the ACK/NACK transmission based on the above, e.g., for the uplink TTI bundle.

[0110] The UE may need to configure/adapt the reception of the ACK/NACK transmitted by the network node.

[0111] The UE may need to configure/adapt the transmission (to be

ACK/NACK-ed) based on the above.

[0112] The network node may need to adapt/configure the reception of the uplink transmission (to be ACK/NACK-ed) based on the above. [0113] The selecting node needs to determine the downlink resources which are or may be used by RAT2. For example, the determining may be based on a message from another node or may be based on a standard or a predefined rule. A message from another node may comprise, e.g., system information, assistance data, etc. The selecting node capable of receiving/understanding signals of RAT2 may also determine whether resources are used by RAT2 transmissions by performing measurements in those resources or searching for known signals associated with RAT2 or determining a certain power profile.

[0114] The downlink transmission of RATI and/or RAT2 may be based, e.g., on FDD, TDD, HD-FDD, or flexible duplex mode. RATI and RAT2 downlink transmissions may or may not have the same duplex.

[0115] A UE capable of adaptive switching between HARQ

synchronous/asynchronous, based on the determined RAT2 downlink resources, may also indicate such capability to the network node.

Using Downlink TTI Bundling/Aggregation in RATI to Avoid Conflict with Uplink

Resources of RAT2

[0116] In this embodiment, downlink TTI bundling is configured and used in RATI adaptively to a subset of time and/or frequency resources allocated for RAT2 uplink transmissions, so that RATI uplink transmissions of a given channel are avoided in resources which are comprised in the RAT2 uplink subset. In other words, in step 1 00 of Figure 7, the node configures downlink TTI bundling in RATI in an adaptive manner based on a subset of time and/or frequency resources allocated for RAT2 uplink transmissions such that RATI uplink transmissions of a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources allocated for RAT2 uplink transmissions.

[0117] RATI may be LTE, while RAT2 may be NR. RATI may be NR, while RAT2 may be LTE.

[0118] The UE may need to adapt/configure the ACK/NACK transmission based on the above, e.g., for the downlink TTI bundle. [0119] The network node may need to adapt/configure the reception of ACK/NACK transmitted by the UE.

[0120] The network node may need to adapt/configure the transmission based on the above.

[0121] The UE may need to adapt/configure the reception of the downlink transmission based on the above.

[0122] The adaptation/configuration may be in the UE (e.g., based on a predefined rule or a control message from the network node) and/or network node. The network node (operating RATI ) may also send a message or coordinate with another network node (operating RAT2).

[0123] The principles of HARQ operation configuration/adaptation may be similar to those described in the section "Using Uplink TTI

Bundling/Aggregation in RATI to Avoid Conflict with Downlink Resources of RAT2," but for the opposite direction (read "downlink" instead of "uplink" and vice versa).

Selecting Asynchronous HARQ in RATI to Avoid the Conflict with RAT2 Uplink

Resources

[0124] In this embodiment, asynchronous HARQ may be configured in RATI to avoid the conflict with RAT2 uplink resources. In other words, in step 100 of Figure 7, the node configures asynchronous HARQ in RATI to avoid conflict with RAT2 uplink resources, where RATI and RAT2 are sharing the same uplink carrier frequency.

[0125] In this embodiment, the selection or use of synchronous or

asynchronous downlink HARQ in RATI may further be based on one or more triggering condition related to RAT2, e.g., asynchronous downlink HARQ is used when RATI and RAT2 are sharing an uplink carrier frequency otherwise synchronous downlink HARQ may be used, or when predefined time instances for downlink HARQ feedback do not match (e.g., not a subset of) the uplink resources available for RATI (i.e., fall into the subset of time and/or frequency resources allocated for RAT2 uplink), etc. [0126] In a further embodiment, the selection of synchronous or

asynchronous HARQ operation may further comprise scheduling the feedback and/or the transmission which triggers the feedback so that the feedback can be transmitted in the resources which are determined to be available for RATI .

[0127] RATI may be LTE, while RAT2 may be NR. RATI may be NR, while RAT2 may be LTE.

[0128] The UE may need to adapt/configure the ACK/NACK transmission based on the above.

[0129] The network node may need to adapt/configure the reception of ACK/NACK transmitted by the UE.

[0130] The network node may need to adapt/configure the transmission (to be ACK/NACK-ed) based on the above.

[0131] The UE may need to adapt/configure the reception of the downlink transmission (to be ACK/NACK-ed) based on the above.

[0132] The adaptation/configuration may be in the UE (e.g., based on a predefined rule or a control message from the network node) and/or network node. The network node (operating RATI ) may also send a message or coordinate with another network node (operating RAT2).

[0133] The principles of HARQ operation configuration/adaptation may be similar to those described in the section "Selecting Asynchronous HARQ in RATI to Avoid the Conflict with RAT2 Downlink Resources," but for the opposite direction (read "downlink" instead of "uplink" and vice versa).

[0134] Figure 8 illustrates one example of a wireless system 10 (e.g., a cellular communications network), in which embodiments of the present disclosure may be implemented. As illustrated, a number of wireless devices 12 (e.g., UEs) wirelessly transmit signals to and receive signals from radio access nodes 14 (e.g., eNBs and/or gNBs), each serving one or more cells 16. The radio access nodes 14 are connected to a core network 1 8.

[0135] Notably, in the embodiments described herein, the wireless system 1 0 includes a number of radio access nodes 14 forming a first radio access network of a first RAT and a number of radio access nodes 14 forming a second radio access network of a second RAT. Note that a particular radio access node 14 may serve cells in both of the RATs. As an example, one of the two RATs may be LTE (e.g., LTE, LTE-A, LTE-Pro, or some enhanced version of LTE) and the other of the two RATs may be Fifth Generation (5G) NR. The two radio access networks (or in other words the two RATs) share downlink resources on the same carrier and/or share uplink resources on the same carrier, but not necessarily for the same wireless device 1 2.

[0136] One or more of the nodes (e.g., one or more of the radio access nodes 14, one or more of the core network nodes, and/or one or more of the wireless devices 12) operate in accordance with the process described above with respect to Figure 7.

[0137] Figure 9 is a schematic block diagram of the wireless device 12 (e.g., UE) according to some embodiments of the present disclosure. As illustrated, the wireless device 12 includes circuitry 20 comprising one or more processors 22 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), and/or the like) and memory 24. The wireless device 12 also includes one or more transceivers 26 each including one or more

transmitters 28 and one or more receivers 30 coupled to one or more antennas 32. In some embodiments, the functionality of the wireless device 12 described above may be implemented in hardware (e.g., via hardware within the circuitry 20 and/or within the processor(s) 22) or be implemented in a combination of hardware and software (e.g., fully or partially implemented in software that is, e.g., stored in the memory 24 and executed by the processor(s) 22).

[0138] In some embodiments, a computer program including instructions which, when executed by the at least one processor 22, causes the at least one processor 22 to carry out at least some of the functionality of the wireless device 12 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0139] Figure 10 is a schematic block diagram of the wireless device 12 (e.g., UE) according to some other embodiments of the present disclosure. The wireless device 12 includes one or more modules 34, each of which is

implemented in software. The module(s) 34 provide the functionality of the wireless device 12 described herein. For example, the modules(s) 34 may include a configuring module operable to perform the function of step 100 of Figure 7 and a using module (optional) operable to perform the function of step 102 of Figure 7.

[0140] Figure 1 1 is a schematic block diagram of a network node 36 (e.g., a radio access node 14 such as, for example, an eNB or gNB) or a core network node according to some embodiments of the present disclosure. As illustrated, the network node 36 includes a control system 38 that includes circuitry comprising one or more processors 40 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like) and memory 42. The control system 38 also includes a network interface 44. In embodiments in which the network node 36 is a radio access node 14, the network node 36 also includes one or more radio units 46 that each include one or more transmitters 48 and one or more receivers 50 coupled to one or more antennas 52. In some embodiments, the functionality of the network node 36 described above may be fully or partially implemented in software that is, e.g., stored in the memory 42 and executed by the processor(s) 40.

[0141] Figure 12 is a schematic block diagram that illustrates a virtualized embodiment of the network node 36 (e.g., the radio access node 14 or a core network node) according to some embodiments of the present disclosure. As used herein, a "virtualized" network node 36 is a network node 36 in which at least a portion of the functionality of the network node 36 is implemented as a virtual component (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, the network node 36 optionally includes the control system 38, as described with respect to Figure 1 1 . In addition, if the network node 36 is the radio access node 14, the network node 36 also includes the one or more radio units 46, as described with respect to Figure 1 1 . The control system 38 (if present) is connected to one or more processing nodes 54 coupled to or included as part of a network(s) 56 via the network interface 44. Alternatively, if the control system 38 is not present, the one or more radio units 46 (if present) are connected to the one or more processing nodes 54 via a network interface(s). Alternatively, all of the functionality of the network node 36 described herein may be implemented in the processing nodes 54. Each processing node 54 includes one or more

processors 58 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like), memory 60, and a network interface 62.

[0142] In this example, functions 64 of the network node 36 described herein are implemented at the one or more processing nodes 54 or distributed across the control system 38 (if present) and the one or more processing nodes 54 in any desired manner. In some particular embodiments, some or all of the functions 64 of the network node 36 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) 54. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 54 and the control system 38 (if present) or alternatively the radio unit(s) 46 (if present) is used in order to carry out at least some of the desired functions. Notably, in some embodiments, the control system 38 may not be included, in which case the radio unit(s) 46 (if present) communicates directly with the processing node(s) 54 via an appropriate network interface(s).

[0143] In some particular embodiments, higher layer functionality (e.g., layer 3 and up and possibly some of layer 2 of the protocol stack) of the network node 36 may be implemented at the processing node(s) 54 as virtual components (i.e., implemented "in the cloud") whereas lower layer functionality (e.g., layer 1 and possibly some of layer 2 of the protocol stack) may be implemented in the radio unit(s) 46 and possibly the control system 38.

[0144] In some embodiments, a computer program including instructions which, when executed by the at least one processor 40, 58, causes the at least one processor 40, 58 to carry out the functionality of the network node 36 or a processing node 54 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as the memory 60).

[0145] Figure 13 is a schematic block diagram of the network node 36 (e.g., the radio access node 14 or a core network node) according to some other embodiments of the present disclosure. The network node 36 includes one or more modules 66, each of which is implemented in software. The module(s) 66 provide the functionality of the network node 36 described herein. In some embodiments, the module(s) 66 may comprise, for example, a configuring module operable to perform the function of step 100 of Figure 7 and a using module (optional) operable to perform the function of step 102 of Figure 7.

Example Embodiments

[0146] While not being limited thereto, some example embodiments of the present disclosure are provided below.

[0147] Embodiment 1 : A method of operation of a node associated with a wireless system comprising a first radio access network of a first RAT and a second radio access network of a second RAT that is different than the first RAT, comprising: configuring (100) TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and the second RAT is avoided when sharing uplink resources and/or downlink resources on the same carrier.

[0148] Embodiment 2: The method of embodiment 1 further comprising using (102) TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network in accordance with a result of configuring (100) TTI

bundling/aggregation and/or asynchronous HARQ in the first radio access network. [0149] Embodiment 3: The method of embodiment 1 or 2 wherein configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring uplink TTI

bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier.

[0150] Embodiment 4: The method of embodiment 3 wherein: the first RAT is LTE and the second RAT is NR; and configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier comprises: configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for NR downlink transmissions in the second radio access network such that LTE downlink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0151 ] Embodiment 5: The method of embodiment 4 wherein the given channel is PHICH with uplink HARQ feedback.

[0152] Embodiment 6: The method of embodiment 3 wherein : the first RAT is NR and the second RAT is LTE; and configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with downlink resources in the second radio access network of the second RAT is avoided when sharing downlink resources on the same carrier comprises: configuring uplink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for LTE downlink transmissions in the second radio access network such that NR downlink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0153] Embodiment 7: The method of embodiment 6 wherein the given channel is a data channel, a control channel, or a channel with uplink HARQ feedback. [0154] Embodiment 8: The method of any one of embodiments 3 to 7 wherein configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT such that at least one parameter of TTI

bundling/aggregation and/or HARQ configuration is based on at least one parameter characterizing resources associated with the second RAT.

[0155] Embodiment 9: The method of any one of embodiments 3 to 7 further comprising adapting uplink TTI size such that downlink transmission for the first RAT are avoided in resources associated with the second RAT.

[0156] Embodiment 10: The method of embodiment 1 or 2 wherein configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT are avoided.

[0157] Embodiment 1 1 : The method of embodiment 1 0 wherein configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT are avoided comprises selecting asynchronous HARQ for use in the first radio access network of the first RAT if the first radio access network and the second radio access network share the same downlink carrier frequency.

[0158] Embodiment 12: The method of embodiment 1 0 or 1 1 wherein configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and downlink resources in the second radio access network of the second RAT are avoided comprises: scheduling asynchronous HARQ feedback and/or a transmission that triggers asynchronous HARQ feedback such that the asynchronous HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first RAT. [0159] Embodiment 13: The method of any one of embodiments 10 to 12 wherein the first RAT is LTE and the second RAT is NR.

[0160] Embodiment 14: The method of any one of embodiments 10 to 12 wherein the first RAT is NR and the second RAT is LTE.

[0161] Embodiment 15: The method of embodiment 1 or 2 wherein configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier.

[0162] Embodiment 16: The method of embodiment 1 5 wherein: the first RAT is LTE and the second RAT is NR; and configuring downlink TTI

bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier comprises: configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for NR uplink transmissions in the second radio access network such that LTE uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

[0163] Embodiment 17: The method of embodiment 1 5 wherein: the first RAT is NR and the second RAT is LTE; and configuring downlink TTI

bundling/aggregation in the first radio access network of the first RAT such that conflict with uplink resources in the second radio access network of the second RAT is avoided when sharing uplink resources on the same carrier comprises: configuring downlink TTI bundling/aggregation in the first radio access network of the first RAT adaptively to a subset of time and/or frequency resources allocated for LTE uplink transmissions in the second radio access network such that NR uplink transmissions of a given channel are avoided in resources which are comprised in the subset. [0164] Embodiment 18: The method of embodiment 1 or 2 wherein configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first RAT comprises configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided.

[0165] Embodiment 19: The method of embodiment 1 8 wherein configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided comprises:

selecting asynchronous HARQ for use in the first radio access network of the first RAT if the first radio access network and the second radio access network share the same uplink carrier frequency.

[0166] Embodiment 20: The method of embodiment 1 8 or 19 wherein configuring (i.e., selecting) asynchronous HARQ in the first radio access network of the first RAT such that a conflict between the first RAT and uplink resources in the second radio access network of the second RAT are avoided comprises: scheduling asynchronous HARQ feedback and/or a transmission that triggers asynchronous HARQ feedback such that the asynchronous HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first RAT.

[0167] Embodiment 21 : The method of any one of embodiments 18 to 20 wherein the first RAT is LTE and the second RAT is NR.

[0168] Embodiment 22: The method of any one of embodiments 18 to 20 wherein the first RAT is NR and the second RAT is LTE.

[0169] Embodiment 23: The method of any one of embodiments 1 to 22 wherein the node is a network node.

[0170] Embodiment 24: The method of any one of embodiments 1 to 22 wherein the node is a wireless device. [0171] Embodiment 25: A node (12, 14, 36, 54) in a cellular communications network (10), the node (1 2, 14, 36, 54) adapted to perform the method of any one of embodiments 1 to 24.

[0172] Embodiment 26: A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 1 to 24.

[0173] Embodiment 27: A carrier containing the computer program of embodiment 26, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0174] Embodiment 28: A node (12, 14, 36, 54) in a cellular communications network (10), comprising: at least one processor (22, 40, 58); and memory (24, 42, 60) comprising instructions executable by the at least one processor (40, 58) whereby the network node (12, 14, 36, 54) is operable to perform the method of any one of embodiments 1 to 24.

[0175] Embodiment 29: A node (12, 14, 36, 54) in a cellular communications network (10), comprising: one or more modules (34, 66) operable to perform the method of any one of embodiments 1 to 24.

[0176] The following acronyms are used throughout this disclosure.

• 3GPP Third Generation Partnership Project

• 5G Fifth Generation

• ACK Acknowledgment

• ARQ Automatic Repeat Request

• ASIC Application Specific Integrated Circuit

• CA Carrier Aggregation

• CC Component Carrier

• CP Cyclic Prefix

• CPE Customer Premises Equipment

• CPU Central Processing Unit

• CQI Channel Quality Indication

• C-RNTI Cell Radio Network Temporary Identifier

• CSI Channel State Information D2D Device-to-Device

DL-SCH Downlink Shared Channel

DSP Digital Signal Processor

eNB Enhanced or Evolved Node B

E-UTRAN Evolved Universal Terrestrial Radio Access Network

FDD Frequency Division Duplexing

FDM Frequency Domain Multiplexing

FPGA Field Programmable Gate Array

GHz Gigahertz

gNB New Radio Base Station

HARQ Hybrid Automatic Repeat Request

HD-FDD Half Duplex Frequency Division Duplexing

IF Intermediate Frequency

kHz Kilohertz

LEE Laptop Embedded Equipment

LME Laptop Mounted Equipment

LTE Long Term Evolution

M2M Machine-to-Machine

MBMS Multimedia Broadcast/Multicast Service

MBSFN Multicast-Broadcast Single Frequency Network

MCE Multi-Cell/Multicast Coordination Entity

MDT Minimization of Drive Tests

MIMO Multiple Input Multiple Output

MME Mobility Management Entity

ms Millisecond

MSR Multi-Standard Radio

NACK Negative Acknowledgment

NB-loT Narrowband Internet of Things

NR New Radio

OFDM Orthogonal Frequency Division Multiplexing PCC Primary Component Carrier

PCell Primary Cell

PDCCH Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PHICH Physical Hybrid Automatic Repeat Request Indicator

Channel

PMI Precoding Matrix Indicator

PSC Primary Serving Cell

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RA Random Access

RAT Radio Access Technology

RB Resource Block

RLM Radio Link Monitoring

RRC Radio Resource Control

RRH Remote Radio Head

RRU Remote Radio Unit

RSRP Reference Signal Received Power

RSRQ Reference Signal Received Quality

RSSI Received Signal Strength Indicator

RSTD Reference Signal Time Difference

RTT Round Trip Time

RV Redundancy Version

Rx Receive

SCC Secondary Component Carrier

SCell Secondary Cell

SINR Signal to Interference plus Noise Ratio

SNR Signal to Noise Ratio

SON Self-Organizing Network

SSC Secondary Serving Cell SSTD System Frame Number and Subframe Timing

Difference

TDD Time Division Duplexing

TDM Time Domain Multiplexing

TOA Time of Arrival

TP Transmission Point

TTI Transmit Time Interval

Tx Transmit

UE User Equipment

UL-SCH Uplink Shared Channel

USB Universal Serial Bus

WID Work Item Description

[0177] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims What is claimed is:

1 . A method of operation of a node associated with a wireless system (1 0) comprising a first radio access network of a first radio access technology and a second radio access network of a second radio access technology that is different than the first radio access technology, comprising:

configuring (1 00) Transmit Time Interval, TTI, bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request, HARQ, in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and the second radio access technology is avoided when sharing uplink resources and/or downlink resources on the same carrier.

2. The method of claim 1 further comprising using (1 02) TTI

bundling/aggregation and/or asynchronous HARQ in the first radio access network in accordance with a result of configuring (1 00) TTI bundling/aggregation and/or asynchronous HARQ in the first radio access network.

3. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively based on a subset of time and/or frequency resources allocated for downlink transmissions for the second radio access technology such that downlink transmissions of the first radio access technology for a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources allocated for downlink transmissions for the second radio access technology.

4. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with downlink resources in the second radio access network of the second radio access technology is avoided when sharing downlink resources on the same carrier, wherein uplink transmissions in the first radio access network of the first radio access technology and downlink transmissions in the first radio access network of the first radio access technology are related in time.

5. The method of claim 4 wherein configuring uplink TTI

bundling/aggregation in the first radio access network of the first radio access technology such that conflict with downlink resources in the second radio access network of the second radio access technology is avoided when sharing downlink resources on the same carrier comprises:

determining a first subset of the shared downlink resources that is allocated for downlink transmissions in the second radio access network of the second radio access technology; and

configuring uplink TTI bundling/aggregation in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions in the second radio access network of the second radio access technology.

6. The method of claim 5 wherein configuring uplink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions comprises:

selecting or delaying a transmission time for an uplink TTI bundle or grant for the uplink TTI bundle in the first radio access network such that an associated HARQ feedback transmission in the first radio access network utilizes a subset of the shared downlink resources that does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions in the second radio access network of the second radio access technology.

7. The method of claim 5 wherein configuring uplink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions comprises:

reducing a maximum number of HARQ transmissions when uplink TTI bundling is used in the first radio access network of the first radio access technology.

8. The method of claim 5 wherein configuring uplink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions comprises:

configuring a bundle size used for uplink TTI bundling in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions in the second radio access network of the second radio access technology.

9. The method of claim 5 wherein configuring uplink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions comprises:

configuring an uplink TTI size in the first radio access network such that a second subset of the shared downlink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with uplink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared downlink resources that is allocated for downlink transmissions in the second radio access network of the second radio access technology.

10. The method of any one of claim 4 wherein:

the first radio access technology is Long Term Evolution, LTE, and the second radio access technology is New Radio, NR; and

configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with downlink resources in the second radio access network of the second radio access technology is avoided when sharing downlink resources on the same carrier comprises:

configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively to a subset of time and/or frequency resources allocated for NR downlink transmissions in the second radio access network such that LTE downlink transmissions of a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources.

1 1 . The method of claim 10 wherein the given channel is Physical HARQ Indicator Channel, PHICH, with uplink HARQ feedback.

12. The method of claim 4 wherein:

the first radio access technology is New Radio, NR, and the second radio access technology is Long Term Evolution, LTE; and

configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with downlink resources in the second radio access network of the second radio access technology is avoided when sharing downlink resources on the same carrier comprises:

configuring uplink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively to a subset of time and/or frequency resources allocated for LTE downlink transmissions in the second radio access network such that NR downlink transmissions of a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources.

13. The method of claim 12 wherein the given channel is a data channel, a control channel, or a channel with uplink HARQ feedback.

14. The method of any one of claims 4 and 1 0 to 13 wherein configuring (1 00) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring (100) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology such that at least one parameter of TTI bundling/aggregation and/or HARQ configuration is based on at least one parameter characterizing resources associated with the second radio access technology.

15. The method of claim 14 wherein the at least one parameter of TTI bundling/aggregation and/or HARQ configuration comprises bundle size, bundle transmission time and resources, transmission power, and/or number of HARQ retransmissions.

16. The method of claim 14 or 1 5 wherein the at least one parameter characterizing resources associated with the second radio access technology comprises time, pattern, numerology, and/or duplex mode for the resources associated with the second radio access technology.

17. The method of any one of claims 4 and 1 0 to 16 wherein configuring (1 00) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises adapting an uplink TTI size for the first radio access network of the first radio access technology such that downlink transmissions for the first radio access technology are avoided in resources associated with the second radio access technology.

18. The method of any one of claims 4 and 1 0 to 16 wherein configuring (1 00) TTI bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring a first transmission and/or transmitting a scheduling grant in the first radio access network of the first radio access technology adaptively to a subset of time and/or frequency resources allocated for downlink transmissions in the second radio access network.

19. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring use of synchronous or asynchronous uplink HARQ in the first radio access network of the first radio access technology based on one or more triggering conditions related to the second radio access technology.

20. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring asynchronous uplink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and downlink resources in the second radio access network of the second radio access technology is avoided.

21 . The method of claim 20 wherein configuring asynchronous uplink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and downlink resources in the second radio access network of the second radio access technology are avoided comprises:

selecting asynchronous uplink HARQ for use in the first radio access network of the first radio access technology if the first radio access network and the second radio access network share the same downlink carrier frequency.

22. The method of claim 20 wherein configuring asynchronous uplink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and downlink resources in the second radio access network of the second radio access technology are avoided comprises:

selecting asynchronous uplink HARQ for use in the first radio access network of the first radio access technology if predefined time instances for uplink HARQ feedback do not match a subset of the shared downlink resources available for the first radio access network of the first radio access technology.

23. The method of claim 20 or 21 wherein configuring asynchronous uplink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and downlink resources in the second radio access network of the second radio access technology are avoided comprises:

scheduling asynchronous uplink HARQ feedback and/or a transmission that triggers asynchronous uplink HARQ feedback such that the asynchronous uplink HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first radio access technology.

24. The method of any one of claims 20 to 23 wherein the first radio access technology is Long Term Evolution, LTE, and the second radio access technology is New Radio, NR.

25. The method of any one of claims 20 to 23 wherein the first radio access technology is New Radio, NR, and the second radio access technology is Long Term Evolution, LTE.

26. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively based on a subset of time and/or frequency resources allocated for uplink transmissions in the second radio access technology such that uplink transmissions in the first radio access network of the first radio access technology for a given channel are avoided in resources which are comprised in the subset of time and/or frequency resources allocated for uplink transmissions in the second radio access technology.

27. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with uplink resources in the second radio access network of the second radio access technology is avoided when sharing uplink resources on the same carrier.

28. The method of claim 27 wherein configuring downlink TTI

bundling/aggregation in the first radio access network of the first radio access technology such that conflict with uplink resources in the second radio access network of the second radio access technology is avoided when sharing uplink resources on the same carrier comprises:

determining a first subset of the shared uplink resources that is allocated for uplink transmissions in the second radio access network of the second radio access technology; and

configuring downlink TTI bundling/aggregation in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink transmissions in the second radio access network of the second radio access technology.

29. The method of claim 28 wherein configuring downlink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink

transmissions in the second radio access network of the second radio access technology comprises: selecting or delaying a transmission time for a downlink TTI bundle or grant for the downlink TTI bundle in the first radio access network such that an associated HARQ feedback transmission in the first radio access network utilizes a subset of the shared uplink resources that does not conflict with the first subset of the shared uplink resources that is allocated for uplink transmissions in the second radio access network of the second radio access technology.

30. The method of claim 28 wherein configuring downlink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink

transmissions in the second radio access network of the second radio access technology comprises:

reducing a maximum number of HARQ transmissions when downlink TTI bundling is used in the first radio access network of the first radio access technology.

31 . The method of claim 28 wherein configuring downlink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink

transmissions in the second radio access network of the second radio access technology comprises:

configuring a bundle size used for downlink TTI bundling in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink transmissions in the second radio access network of the second radio access technology.

32. The method of claim 28 wherein configuring downlink TTI

bundling/aggregation in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI

bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink

transmissions in the second radio access network of the second radio access technology comprises:

configuring a downlink TTI size in the first radio access network such that a second subset of the shared uplink resources that is utilized by the first radio access network for HARQ feedback transmissions associated with downlink TTI bundling/aggregation in the first radio access network does not conflict with the first subset of the shared uplink resources that is allocated for uplink

transmissions in the second radio access network of the second radio access technology.

33. The method of claim 27 wherein:

the first radio access technology is Long Term Evolution, LTE, and the second radio access technology is New Radio, NR; and

configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with uplink resources in the second radio access network of the second radio access technology is avoided when sharing uplink resources on the same carrier comprises:

configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively to a subset of time and/or frequency resources allocated for NR uplink transmissions in the second radio access network such that LTE uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

34. The method of claim 27 wherein:

the first radio access technology is New Radio, NR, and the second radio access technology is Long Term Evolution, LTE; and

configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology such that conflict with uplink resources in the second radio access network of the second radio access technology is avoided when sharing uplink resources on the same carrier comprises:

configuring downlink TTI bundling/aggregation in the first radio access network of the first radio access technology adaptively to a subset of time and/or frequency resources allocated for LTE uplink transmissions in the second radio access network such that NR uplink transmissions of a given channel are avoided in resources which are comprised in the subset.

35. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring use of synchronous or asynchronous downlink HARQ in the first radio access network of the first radio access technology based on one or more triggering conditions related to the second radio access technology.

36. The method of claim 1 or 2 wherein configuring (1 00) TTI

bundling/aggregation and/or asynchronous HARQ on the first radio access network of the first radio access technology comprises configuring asynchronous downlink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and uplink resources in the second radio access network of the second radio access technology are avoided.

37. The method of claim 36 wherein configuring asynchronous downlink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and uplink resources in the second radio access network of the second radio access technology are avoided comprises:

selecting asynchronous downlink HARQ for use in the first radio access network of the first radio access technology if the first radio access network and the second radio access network share the same uplink carrier frequency.

38. The method of claim 36 wherein configuring asynchronous downlink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and uplink resources in the second radio access network of the second radio access technology are avoided comprises:

selecting asynchronous downlink HARQ for use in the first radio access network of the first radio access technology if predefined time instances for downlink HARQ feedback do not match a subset of the shared uplink resources available for the first radio access network of the first radio access technology.

39. The method of claim 36 or 37 wherein configuring asynchronous downlink HARQ in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and uplink resources in the second radio access network of the second radio access technology are avoided comprises:

scheduling asynchronous downlink HARQ feedback and/or a transmission that triggers asynchronous downlink HARQ feedback such that the asynchronous downlink HARQ feedback is transmitted in the resources that are determined to be available for the first radio access network of the first radio access technology.

40. The method of any one of claims 36 to 39 wherein the first radio access technology is Long Term Evolution, LTE, and the second radio access

technology is New Radio, NR.

41 . The method of any one of claims 36 to 39 wherein the first radio access technology is New Radio, NR, and the second radio access technology is Long Term Evolution, LTE.

42. The method of any one of claims 1 to 41 wherein the node is a network node.

43. The method of any one of claims 1 to 41 wherein the node is a wireless device.

44. A node (12, 14, 36, 54) associated with a wireless system (10) comprising a first radio access network of a first radio access technology and a second radio access network of a second radio access technology that is different than the first radio access technology, the node (12, 14, 36, 54) adapted to:

configure Transmit Time Interval, TTI, bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request, HARQ, in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and the second radio access technology is avoided when sharing uplink resources and/or downlink resources on the same carrier.

45. The node (12, 14, 36, 54) of claim 44 wherein the node (12, 14, 36, 54) is further adapted to perform the method of any one of claims 2 to 43.

46. A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1 to 43.

47. A carrier containing the computer program of claim 46, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

48. A node (12, 14, 36, 54) associated with a wireless system (10) comprising a first radio access network of a first radio access technology and a second radio access network of a second radio access technology that is different than the first radio access technology, the node (1 2, 14, 36, 54) comprising:

at least one processor (22, 40, 58); and

memory (24, 42, 60) comprising instructions executable by the at least one processor (22, 40, 58) whereby the node (1 2, 14, 36, 54) is operable to

configure Transmit Time Interval, TTI, bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request, HARQ, in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and the second radio access technology is avoided when sharing uplink resources and/or downlink resources on the same carrier.

49. The node (12, 14, 36, 54) of claim 48 wherein, by execution of the instructions, the node (1 2, 14, 36, 54) is further operable to perform the method of any one of claims 2 to 43.

50. A node (12, 14, 36, 54) associated with a wireless system (10) comprising a first radio access network of a first radio access technology and a second radio access network of a second radio access technology that is different than the first radio access technology, the node (1 2, 14, 36, 54) comprising:

a configuring module (34, 66) operable to configure Transmit Time

Interval, TTI, bundling/aggregation and/or asynchronous Hybrid Automatic Repeat Request, HARQ, in the first radio access network of the first radio access technology such that a conflict between the first radio access technology and the second radio access technology is avoided when sharing uplink resources and/or downlink resources on the same carrier.

51 . The node (12, 14, 36, 54) of claim 50 further comprising one or more modules (34, 66) operable to perform the method of any one of claims 2 to 43.