WO2022031215A1

WO2022031215A1 - Narrowband channel reporting technique

Info

Publication number: WO2022031215A1
Application number: PCT/SE2021/050779
Authority: WO
Inventors: Gerardo Agni MEDINA ACOSTA; Kazuyoshi Uesaka; Liping Zhang; Jie Chen; Ritesh SHREEVASTAV; Emre YAVUZ
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2020-08-07
Filing date: 2021-08-06
Publication date: 2022-02-10
Anticipated expiration: 2023-02-07

Abstract

A technique for reporting a channel quality indicator, CQI, of a narrowband channel (502) between a radio device (100) and a network node (200) in a radio network (500) is described. As to a method aspect of the technique, a reference resource comprising a group of downlink, DL, physical resource blocks, PRBs, of the narrowband channel (502) from the network node (200) is measured at the radio device (100). Based on the measuring, a CQI index of the CQI is derived for which atransport block, TB, occupying the reference resource with a radio schemecorresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a narrowband physical DL shared channel, NPDSCH, TB. The radio scheme comprises 16-QAM as a modulation scheme. A report to the network node (200) is transmitted. The report is indicative of the derived CQI index.

Description

Narrowband channel reporting technique

Technical Field

The present disclosure relates to reporting the channel quality of a narrowband channel. More specifically, and without limitation, methods and devices for reporting a channel quality indicator of a narrowband channel and for receiving a channel quality indicator of a narrowband channel are provided.

Background

Long Term Evolution (LTE) and Fifth Generation New Radio (5G NR) as specified by the Third generation Partnership Project (3GPP) uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL) from a network node (e.g., eNodeB or gNodeB) to a radio device termed user equipment (UE). The basic DL physical resource can thus be seen as a time-frequency grid of resource elements, each resource element corresponding to one OFDM subcarrier during one OFDM symbol interval. The resource elements are allocated in units of physical resource blocks (PRBs). A PRB is 180 kHz wide in frequency and 1 slot long in time. In frequency, PRB may be 12 x 15 kHz subcarriers or 24 x 7.5 kHz subcarriers wide. The number of subcarriers used per PRB for most channels and signals is 12 subcarriers.

Aside mobile broadband (MBB) using a plurality of PRBs in the frequency, Narrowband Internet of Things (NB-loT) is a Low Power Wide Area (LPWA) system. NB-loT is optimized for applications sending and receiving small quantities of data, as many loT devices do, e.g. infrequently exchanging data with a back-end system. Furthermore, while MBB technologies offer excellent outdoor coverage, their reception deep within buildings is often limited. Furthermore, a battery life of several years is feasible using NB-loT.

The document WO 2017/078603 Al describes a system for deriving channel feedback for a physical channel based on an indication of the number of transmission repetitions. While NB-loT has proven to provide reliable and power-efficient radio connectivity, the potential of channel capacity is not used efficiently at least in some channel conditions.

Summary

Accordingly, there is a need for a radio technology that allows using the channel capacity of narrowband channels more efficiently in at least some scenarios.

As to a first method aspect, a method of reporting a channel quality indicator (CQ.I) of a narrowband (NB) channel between a radio device and a network node in a radio network is provided. The method comprises or initiates a step of measuring, at the radio device, a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel from the network node. The method further comprises or initiates a step of deriving, based on the measuring, a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The method further comprises or initiates a step of transmitting a report to the network node. The report is indicative of the derived CQI index.

The first method aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the claims 1 to 33. Furthermore, the first method aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

In at least some embodiments, based on the reported CQI, the network node is enabled to use a modulation order in the DL on the narrowband channel that uses the channel capacity of the narrowband channel more efficiently.

Same or further embodiments may harness the channel capacity of the narrowband channel under good channel conditions based on the report being indicative of a CQI index for which a TB using 16-QAM is receivable with the prescribed or required reliability. The technique may be implemented as a method of NB-loT channel quality reporting for the support of 16-QAM in downlink.

The report may be indicative of a channel quality of the narrowband channel in terms of the CQI. Based on the reported CQI, the network node can selectively use 16-QAM in the DL.

The technique may be applied to a narrowband internet of things (NB-loT) device as the radio device and/or a NB-loT physical DL shared channel (NPDSCH) on the narrowband channel. Optionally, the reported CQI may be further indicative of an (e.g., achievable) code rate and/or transport block size (TBS) of the transport block (TB). Alternatively or in addition, a mapping between CQI indices and ranges of the code rate may depend on whether the radio network provides the narrowband channel in a stand-alone implementation, an in-band implementation, or a guardband implementation.

The transport block error probability may be a block error rate (BLER).

The radio network may be Low Power Wide Area Network (LPWAN).

The measuring may comprise an unrestricted observation interval (e.g., measurement interval) in time and/or frequency.

The CQI of the narrowband channel may relate to the DL of the narrowband channel. Alternatively or in addition, the narrowband channel may be a unicast channel.

Herein, "receivable" may be equivalent to or may encompass "can be received" or decodable, e.g., successfully decodable.

The radio scheme may also be referred to as a transmission scheme. The CQI index may also be referred to as a CQI value.

The modulation scheme may also be referred to as a modulation and coding scheme (MCS). Alternatively or in addition, the radio scheme may comprise an MCS, wherein the MCS comprises the modulation scheme. The measuring may comprise measuring a signal to noise ratio (SNR) or a signal to noise and interference ratio (SNIR).

The method may be applied to a NB-loT device as the radio device, e.g., using 16- QAM as the modulation scheme. Alternatively or in addition, the method may be applied to a NPDSCH on the narrowband channel.

The CQI index may be derived for the TB being receivable on a NPDSCH.

The CQI index may be derived out of a set of CQI indices. The derived CQI index may be the greatest CQI index out of the set of CQI indices, for which the TB is receivable using the radio scheme corresponding to the CQI index with the transport block error probability equal to or less than the predefined threshold.

Alternatively or in addition, the CQI index may be derived out of a set of CQI indices. The derived CQI index may be the greatest CQI index out of the set of CQI indices, for which according with measurements performed on the reference resource, the TB is receivable by the radio device with the transport block error probability equal to or less than the predefined threshold.

The set may be an index column of at least one predefined mapping table (e.g., a standardized and/or hard-coded table). The at least one predefined mapping table may be stored at each of the radio device and the network node.

The derived CQI index may be a CQI value, e.g., out of an index column of the at least one predefined mapping table.

The CQI may be a CQI for a Narrowband internet-of-things (NB-loT) Physical DL Control Channel (CQI-NPDCCH-NB), e.g., according to table 9.1.22.15-1 in the 3GPP document TS 36.133, version 16.6.0. Alternatively or in addition, the set of CQI indices may correspond to the CQI indices in at least one of the table 9.1.22.15-1 and the table 9.1.22.15-2 of the 3GPP document TS 36.133, version 16.6.0.

The radio device may derive, e.g., for each CQI value, the greatest (i.e., highest) CQI index in the set which satisfies the condition that the transport block error probability is equal to or less than the predefined threshold. If the radio scheme (e.g., the combination) corresponding to the least CQI index (e.g., the index "1" or the first index in the predefined table) does not fulfil the condition, the radio device may report a CQI report associated with QPSK (Quadrature Phase Shift Keying), or the report may be indicative of a CQI index equal to zero ("0") and/or may be indicative of the absence of a measurement ("no measurement).

The set may be restricted to those CQI indices that correspond to the 16-QAM, which may also be referred to as a first subset of the set.

Herein, those CQI indices for which the radio schemes corresponding to the respective CQI indices comprise the 16-QAM as the modulation scheme may also be referred to as CQI indices associated with (e.g., mapped to) the 16-QAM. The CQI indices associated with the 16-QAM may be referred to as a first subset in the set (e.g., the set of all CQI indices).

The reference resource may be a CSI reference resource or a reference resource for channel state information (CSI) of the narrowband channel.

The method may be performed by the radio device. The radio device may be a UE Category NB1.

The TB using the radio scheme corresponding to the CQI index may be receivable at the radio device with the transport block error probability equal to or less than the predefined threshold.

The narrowband channel may comprise one or more physical channels, optionally at least one of a Narrowband internet-of-things (NB-loT) Physical DL Control Channel (NPDCCH) and a NB-loT Physical DL Shared Channel (NPDSCH).

The NPDCCH may comprise narrowband control channel elements (NCCEs). The radio schemes corresponding to the CQI indices in the first subset may be used with NPDCCH Format 0 or NPDCCH Format 1.

The CQI index may correspond to or may be indicative of the modulation scheme (e.g., a MCS) on the narrowband channel, optionally on the NPDSCH and/or for the TB.

The CQI index may correspond to or may be indicative of a modulation and coding scheme (MCS). The radio device may be a Narrowband Internet-of-Things (NB-loT) radio device and/or a radio device with Bandwidth reduced Low complexity (BL).

At least one of the radio device, the network node, and the narrowband channel between the radio device and the network node may be configured for coverage enhancement.

The coverage enhancement may include repetitions of the TB according to a repetition level.

The coverage enhancement may comprise and/or the repetition level may be indicative of more than 10 or more than 100 repetitions of the TB.

The CQI index may correspond to or may be indicative of a repetition level on the narrowband channel, optionally on the NPDCCH and/or for the TB.

The repetition level may be the number of repetitions. Increasing the CQI index (e.g., by one), e.g., each increase of the CQI index by 1, may correspond to an increase in the repetition level by a factor of 2 or 4 or 8.

The TB may be a NPDCCH TB. Alternatively or in addition, the CQI index may be derived for the TB being receivable on a NPDCCH.

The TB may be a single TB. Alternatively or in addition, the transport block error probability of the TB may relate to the probability of a single TB being receivable.

The TB may be receivable with the block error probability equal to or less than the predefined threshold when using the radio scheme (e.g., the combination of the modulation scheme and the TBS) corresponding to the derived CQI index.

Alternatively or in addition, the report may be indicative of a reference number of repetitions.

The predefined threshold may be 0.1 or 0.01 or between 0.1 and 0.01.

A single NPDSCH TB of the TB with a combination of the modulation scheme and a transport block size (TBS) corresponding to the CQI index, and occupying the group of DL PRBs termed CSI reference resource as the resource source, may be receivable with the transport block error probability not exceeding 0.1. The narrowband channel may be a narrowband internet-of-things (NB-loT) channel. Alternatively or in addition, the radio device may be a NB-loT device.

Alternatively or in addition, the radio network may use a radio access technology (RAT) for the NB-loT.

A bandwidth of the narrowband channel may be equal to or less than 180 kHz. Alternatively or in addition, the narrowband channel is a half-duplex channel.

The narrowband channel between the radio device and the network node may operate in a half-duplex mode.

Alternatively or in addition, a bandwidth of the narrowband may be equal to or less than 200 kHz, e.g., equal to or less than 180 kHz. The bandwidth may be a device receive bandwidth of the radio device.

The reference resource may comprise a reference signal (RS).

The reference resource may comprise at least one of a DL RS and a narrowband reference signal (NRS).

The radio scheme may comprise a combination of the modulation scheme and a transport block size (TBS).

The reported CQI index may be further indicative of a code rate and/or TBS of the TB.

Each of the CQI indices (e.g., in the first subset) may encompass a different set of transport blocks (TBs) transmittable or usable with the 16-QAM modulation scheme.

Alternatively or in addition, all the TBs transmittable or usable with 16-QAM may be grouped into a number of sets of TBs associated to the same number of CQI indices.

All the TBs transmittable or usable with 16-QAM may be grouped into three sets of TBs associated to three CQI indices. The tree CQI indices in the report may be indicative of the usage of 16-QAM. Alternatively or in addition, the tree CQI indices may be on the three reserved states in table 9.1.22.15-1 of the 3GPP document TS 36.133 (e.g., version 16.6.0), clause 9.1.22.15.

All the TBs transmittable with 16-QAM may be grouped into sets of TBs based on the code rate and/or TB indices.

The radio scheme may comprise a combination of the modulation scheme and a repetition level.

The modulation scheme may comprise a modulation and coding scheme (MCS). The modulation scheme or the MCS may apply to the NPDSCH of the narrowband channel.

A mapping may map the derived CQI index or each CQI index or each CQI index in the set of CQI indices to the radio scheme corresponding to the respective CQI index.

The mapping may, for the derived CQI index or each CQI index or each CQI index in the set of CQI indices, be indicative of the radio scheme corresponding to the respective CQI index, e.g., the MCS and/or the repetition level corresponding to the respective CQI index.

The mapping may comprise or may be implemented by at least one predefined mapping table.

The mapping or the at least one predefined mapping table may be indicative of the combination of the modulation scheme (e.g., the MCS) and the repetition level corresponding to the respective CQI index.

The at least one predefined table may, for each CQI index in the set of CQI indices, be indicative of the combination of the modulation scheme and the repetition level corresponding to the respective CQI index. The mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with a or the repetition level being 1.

Alternatively, the repetition level is greater than 1.

For example, the at least one predefined mapping table comprises an index column that is indicative of the CQI indices in the set of CQI indices, a repetition level column that is indicative of the repetition levels (e.g., for the NPDCCH) corresponding to the respective CQI indices, and a modulation scheme column that is indicative of the modulation schemes corresponding to the respective CQI indices.

According to the repetition level being 1, the TP may be transmitted only once. The repetition level being 1 may be indicative of a single transmission, e.g., on the NPDCCH or the NPDSCH. In combination with the 16-QAM as the modulation scheme, a repetition level greater than 1 may be applied (e.g., only) to the NPDCCH while the repetition level 1 is applied to the NPDSCH.

The mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being equal to or less than 16 or 32 or 64.

The mapping, optionally the same predefined mapping table, may map each CQI index in a first subset of the set of CQI indices to the radio scheme comprising 16- QAM as the modulation scheme and further maps each CQI index in a second subset of the set of CQI indices to the radio scheme corresponding to the respective CQI index. The respective radio schemes corresponding to the CQI indices in the second subset may comprise a modulation scheme other than the 16-QAM.

The second subset may be disjoint from the first subset.

Each CQI index in the second subset may be less than each CQI index in the first subset. Each CQI index in the second subset may correspond to a channel quality of the narrowband channel lesser than the channel quality of the narrowband channel of each CQI index in the first subset.

Each or at least one of the respective radio schemes corresponding to the CQI indices in the second subset may comprise quadrature phase-shift keying (QPSK) or binary phase-shift keying (BPSK) as the modulation scheme and/or a repetition level equal to or greater than 1.

At least one of the respective radio schemes corresponding to the CQI indices in the second subset may comprise a repetition level greater than 1.

The set may comprise a number of N=2ⁿ or N=2ⁿ-1 CQI indices for an integer n (e.g., n=4). The first subset may comprise a number of Ni CQI indices and the second subset may comprise a number of /V₂ CQI indices, wherein N = N + /V₂. For example, N = 13 and /₂ = 3 (or vice versa).

Herein, the CQI indices of the first subset (e.g., the respective CQI values of the first subset) may be referred to as candidateRep-M, candidateRep-N, and candidateRep-O, respectively.

Different CQI indices in the first subset may correspond to different ranges of a code rate of the respective radio scheme.

Optionally, the modulation scheme column or a further column (e.g., a code rate column) of the at least one predefined mapping table may be indicative of the ranges of the code rate.

Alternatively or in addition, the radio scheme may comprise a coding scheme determining the code rate. The coding scheme may be part of the MCS. The coding scheme may comprise channel coding with an error-correction code (e.g., encoding at the network node and decoding at the radio device) and/or puncturing. Puncturing may comprise removing one or more parity bits after the encoding with the error-correction code. This may have the same effect as encoding with an error-correction code with a higher rate, or less redundancy.

The radio scheme may comprise or define the code rate. Alternatively or in addition, the code rate may be achievable by the TB using the radio scheme. The different ranges of the code rate may be pairwise disjoint.

The radio scheme may comprise a TBS of the TB. Different CQI indices in the first subset may correspond to different ranges of a TBS of the TB with the respective radio scheme.

The different ranges of the TBS may be pairwise disjoint.

The ranges may be defined or delimited by range thresholds.

The range thresholds may correspond to fractional numbers of achievable code rates of the TB using the respective radio schemes.

The ranges or the range thresholds may depend on whether the radio network is a guard-band deployment, a stand-alone deployment, or an in-band deployment.

The channel quality reporting for 16-QAM in the DL may be created through defining 3 ranges using thresholds based on achievable code rates, which are associated with an NPDCCH repetition level equal to 1.

The ranges or the range thresholds may depend on a level of a coverage enhancement on the narrowband channel.

The level of the coverage enhancement (also: coverage enhancement level) may comprise a number of repetitions of the TB. The repetition level may be an example of the coverage enhancement level.

Greater CQI indices in the first subset may correspond to the ranges having greater values of the code rate or the TBS.

In other words, the ranges may be sorted in ascending order of the CQI index. Alternatively, the lesser CQI indices in the first subset may correspond to the ranges having greater values of the code rate or the TBS. In other words, the ranges may be sorted in descending order of the CQI index. The mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 1 for a first CQI index in the first subset. Alternatively or in addition, the mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 2 for a second CQI index and a third CQI index in the first subset.

The mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 1 for a first CQI index and a second CQI index in the first subset. Alternatively or in addition, the mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 2 for a third CQI index in the first subset.

The first CQI index in the first subset may correspond to a first range of the code rate. The second CQI index in the first subset may correspond to a second range of the code rate. The third CQI index in the first subset may correspond to a third range of the code rate.

Herein, the range thresholds of the first, second, and third ranges may also be referred to as E, F, and G, respectively.

The narrowband channel may comprise a NB-loT or NB Physical DL Control Channel (NPDCCH) comprising narrowband control channel elements (NCCEs). The radio schemes corresponding to the CQI indices in the first subset may be used in the NCCEs with either NPDCCH Format 0 or NPDCCH Format 1.

The narrowband channel may comprise a NB-loT or NB Physical DL Control Channel (NPDCCH) comprising narrowband control channel elements (NCCEs). The radio schemes corresponding to the CQI indices in the first subset may be used in the NCCEs only with NPDCCH Format 0.

The report may be a CSI feedback.

The report may be, or may be transmitted in, a message of a random access (RA) procedure, optionally in a Message 3 (Msg3) of the RA procedure or an Early Data Transmission (EDT) of the RA procedure. Alternatively or in addition, the report may be, or may be transmitted in, a preconfigured uplink resource (PUR). The report may be, or may be transmitted in, a medium access control (MAC) packet data unit (PDU) or a MAC control element (MAC CE).

The report may comprise a bit field that is indicative of the CQI index. Optionally, the bit field may comprise 4 bits.

The MAC CE may comprises a bit field that is indicative of the CQI index. Optionally, the bit field may comprise 6 bits.

The bit field may correspond to CQI-NPDCCH-NB as defined in the 3GPP document TS 36.331, version 16.1.1.

Consecutive 4 bits in the bit field may be configured to represent the CQI indices in the second subset of the set of CQI indices. Alternatively or in addition, 2 bits in the bit field outside of the consecutive 4 bits may be configured to represent the CQI indices in the first subset of the set of CQI indices.

The bit field may be representative of the CQI indices in the second subset if 2 bits in the bit field outside of the consecutive 4 bits are zero. Alternatively or in addition, the bit field may be representative of the CQI indices in the first subset if at least one bit in the bit field outside of the consecutive 4 bits is non-zero.

The mapping may comprise or may be implemented by a first mapping table that is indicative of the CQI index for the NPDCCH of the narrowband channel and a second mapping table that is indicative of the CQI index for the NPDSCH of the narrowband channel.

The method may further comprise or initiate the step of receiving a radio resource control (RRC) message indicative of whether or not the network node or the radio network supports 16-QAM as the modulation scheme on the narrowband channel.

As to a second method aspect, a method of receiving a channel quality indicator (CQI) of a narrowband (NB) channel between a radio device and a network node in a radio network is provided. The method comprises or initiates a step of transmitting on a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel to the radio device. The method further comprises or initiates a step of receiving, based on a measurement of the reference resource, a report from the radio device. The report is indicative of a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The method further comprises or initiates a step of transmitting in the DL on the narrowband channel using a radio scheme depending on the received CQI index. The used radio scheme comprises 16-QAM as the modulation scheme.

The second method aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the claims 34 to 36. Furthermore, the second method aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

The used radio scheme may depend on the received CQI index in that the used radio scheme may be, or may correspond to, or may comprise, the radio scheme corresponding to the received CQI index.

The CQI index in the report (i.e., the reported CQI index) may be derived (e.g., estimated) for the TB to be transmitted. The transmitting on the DL may comprise transmitting the TB using 16-QAM as the modulation scheme.

The method is performed by the network node.

The second method aspect may further comprise any feature and/or any step disclosed in the context of the first method aspect, or a feature and/or step corresponding thereto, e.g., a receiver counterpart to a transmitter feature or step.

Some aspects of the technique may be implemented by changes and/or additions to the 3GPP document TS 36.133, version 16.6.0; the 3GPP document TS 36.213, version 16.2.0; the 3GPP document TS 36.331 version 16.1.1; and/or a corresponding document in the 3GPP TS 38-series.

Any radio device may be a user equipment (UE), e.g., according to a 3GPP specification. The radio device and/or the network node (e.g., a base station) and/or a radio access network (RAN) comprising multiple network nodes may form, or may be part of, the radio network, e.g., according to the Third Generation Partnership Project (3GPP) or according to the standard family IEEE 802.11 (Wi-Fi). The first method aspect and/or the second method aspect may be performed by one or more embodiments of the radio device and network node (e.g., the RAN), respectively.

The RAN may comprise one or more network nodes, e.g., each or collectively performing the second method aspect. Alternatively or in addition, the radio network may be a vehicular, ad hoc and/or mesh network comprising two or more radio devices, e.g., a remote radio device acting as the radio device and/or a relay radio device acting as the network node.

Any of the radio devices may be a 3GPP user equipment (UE) or a Wi-Fi station (STA). The radio device may be a mobile or portable station, a device for machinetype communication (MTC), a device for narrowband Internet of Things (NB-loT) or a combination thereof. Examples for the UE and the mobile station include a mobile phone, a tablet computer and a self-driving vehicle. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device or the NB-loT device include robots, sensors and/or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-loT device may be implemented in a manufacturing plant, household appliances and consumer electronics.

The radio device may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with the network node or the relay radio device (e.g., according to 3GPP Proximity Services, ProSe).

The network node (e.g., a base station) may encompass any station that is configured to provide radio access to any of the radio devices. The network nodes may also be referred to as cell, transmission and reception point (TRP), radio access node or access point (AP). The base station and/or the relay radio device may provide a data link to a host computer providing user data to the radio device in the DL of the narrowband channel. Examples for the base stations may include a 3G base station or Node B, 4G base station or eNodeB, a 5G base station or gNodeB, a Wi-Fi AP and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

The radio network or the RAN may be implemented according to the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE) and/or 3GPP New Radio (NR).

Any aspect of the technique may be implemented on a Physical Layer (PHY), a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a packet data convergence protocol (PDCP) layer, and/or a Radio Resource Control (RRC) layer of a protocol stack for the radio communication.

As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the method aspects disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download, e.g., via the radio network, the RAN, the Internet and/or the host computer. Alternatively, or in addition, any of the method aspects may be encoded in a Field-Programmable Gate Array (FPGA) and/or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

As to a first device aspect, a radio device for reporting a channel quality indicator (CQI) of a narrowband (NB) channel between the radio device and a network node in a radio network is provided. The radio device comprises memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device is operable to measure, at the radio device, a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel from the network node. The radio device is further operable to derive, based on the measurement, a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The radio device is further operable to transmit a report to the network node. The report is indicative of the derived CQI index.

The first device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the embodiments 38 to 39. Furthermore, the first device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

As to a further first device aspect, a radio device for reporting a channel quality indicator (CQI) of a narrowband (NB) channel between the radio device and a network node in a radio network is provided. The radio device is configured to measure, at the radio device, a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel from the network node. The radio device is further configured to derive, based on the measurement, a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The radio device is further configured to transmit a report to the network node. The report is indicative of the derived CQI index.

The further first device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the embodiments 40 to 41. Furthermore, the further first device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

Alternatively or in addition, the device may be configured to perform any one of the steps of the first method aspect.

As to a still further first device aspect, a user equipment (UE) according to the first device aspect or the further first device aspect is provided.

The still further first device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the embodiments 42 to 43. Furthermore, the still further first device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

As to a second device aspect, a network node for receiving a channel quality indicator (CQ.I) of a narrowband (NB) channel between a radio device and the network node in a radio network is provided. The network node comprises memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node is operable to transmit on a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel to the radio device. The network node is further operable to receive, based on a measurement of the reference resource, a report from the radio device. The report is indicative of a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The network node is further operable to transmit in the DL on the narrowband channel using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

The second device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the claims 44 to 45. Furthermore, the second device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

As to a further second device aspect, a network node for receiving a channel quality indicator (CQI) of a narrowband (NB) channel between a radio device and the network node in a radio network is provided. The network node is configured to transmit on a reference resource comprising a group of downlink (DL) physical resource blocks (PRBs) of the NB channel to the radio device. The network node is further configured to receive, based on a measurement of the reference resource, a report from the radio device, the report is indicative of a CQI index of the CQI for which a transport block (TB) occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold. The TB is a NB physical DL shared channel (NPDSCH) TB. The radio scheme comprises 16 Quadrature Amplitude Modulation (16-QAM) as a modulation scheme. The network node is further configured to transmit in the DL on the narrowband channel using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

Alternatively or in addition, the device may be configured to perform any one of the steps of the second method aspect.

The further second device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the embodiments 46 to 47. Furthermore, the further second device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

As to a still further second device aspect, a base station according to the second device aspect or the further second device aspect is provided.

The still further second device aspect may be provided or implemented alone or in combination with any one of the claims in the list of claims, particularly the embodiments 48 to 49. Furthermore, the still further second device aspect may be provided or implemented alone or in combination with any one of the embodiments described herein below.

As to a still further aspect a communication system including a host computer is provided. The host computer comprises a processing circuitry configured to provide user data. The host computer further comprises a communication interface configured to forward the user data to a cellular network (e.g., the RAN and/or the base station) for transmission to a UE. A processing circuitry of the cellular network is configured to execute any one of the steps of the second method aspect. The UE comprises a radio interface and processing circuitry, which is configured to execute any one of the steps of the first method aspect.

The communication system may further include the UE. Alternatively, or in addition, the cellular network may further include one or more base stations configured for radio communication with the UE and/or to provide a data link between the UE and the host computer using the first and/or second method aspects.

The processing circuitry of the host computer may be configured to execute a host application, thereby providing the user data and/or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the UE may be configured to execute a client application associated with the host application.

Any one of the devices, the UE, the network node (e.g., the base station), the communication system or any node or station for embodying the technique may further include any feature disclosed in the context of the method aspects, and vice versa. Particularly, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspects.

Brief Description of the Drawings

Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

Fig. 1 shows a schematic block diagram of an embodiment of a device for reporting a CQI of a narrowband channel;

Fig. 2 shows a schematic block diagram of an embodiment of a device for receiving a CQI of a narrowband channel;

Fig. 3 shows a flowchart for a method of reporting a CQI of a narrowband channel, which method may be implementable by the device of Fig. 1;

Fig. 4 shows a flowchart for a method of receiving a CQI of a narrowband channel, which method may be implementable by the device of Fig. 2;

Fig. 5 schematically illustrates an exemplary network environment for implementing the devices of Figs. 1 and 2;

Fig. 6 schematically illustrates a first signaling diagram for embodiments of the devices of Figs. 1 and 2 in radio communication according to embodiments of the methods of Figs. 3 and 4;

Fig. 7 schematically illustrates a second signaling diagram for embodiments of the devices of Figs. 1 and 2 in radio communication according to embodiments of the methods of Figs. 3 and 4; Fig. 8 shows a schematic block diagram of a radio device embodying the device of Fig. 1;

Fig. 9 shows a schematic block diagram of a network node embodying the device of Fig. 2;

Fig. 10 schematically illustrates an example telecommunication network connected via an intermediate network to a host computer;

Fig. 11 shows a generalized block diagram of a host computer communicating via a base station or radio device functioning as a gateway with a user equipment over a partially wireless connection; and

Figs. 12 and 13 show flowcharts for methods implemented in a communication system including a host computer, a base station or radio device functioning as a gateway and a user equipment.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for 3GPP LTE, it is readily apparent that the technique described herein may also be implemented for any other radio communication technique, including a New Radio (NR) or 5G implementation, 3GPP LTE-Advanced or a related radio access technique such as MulteFire, a Wireless Local Area Network (WLAN) implementation according to the standard family IEEE 802.11, for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy, Bluetooth Mesh Networking and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance or for ZigBee based on IEEE 802.15.4.

Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

Fig. 1 schematically illustrates a block diagram of an embodiment of a device for reporting a channel quality indicator (CQ.I ) of a narrowband channel between a radio device and a network node in a radio network. The device is generically referred to by reference sign 100.

The device 100 comprises a reference resource measuring module 102 that performs the step of measuring, a deriving module 104 that performs the step of deriving, and a CQI report transmitting module 106 that performs the step of transmitting, e.g., according to the first device aspect and/or any one of the embodiments described herein below, optionally in combination.

The reference resource measuring module 102 may measure, at the radio device, a reference resource comprising a group of DL PRBs of the NB channel from the network node. The deriving module 104 may derive, based on the measuring, a CQI index of the CQI for which a TB occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NPDSCH TB, the radio scheme comprising 16-QAM as a modulation scheme. The transmitting module 106 may transmit a report to the network node, the report being indicative of the derived CQI index.

Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality.

The device 100 may also be referred to as, or may be embodied by, the radio device (or briefly: UE). The radio device 100 and the network node may be in direct radio communication, e.g., during the measuring and the transmitting. The network node may be embodied by the device 200. Fig. 2 schematically illustrates a block diagram of an embodiment of a device for receiving a channel quality indicator (CQ.I ) of a narrowband channel between a radio device and a network node in a radio network. The device is generically referred to by reference sign 200.

The device 200 comprises a reference resource transmitting module 202 that performs the step of transmitting on a reference resource, a CQI report receiving module 204 that performs the step of receiving, and transport block transmitting module 206 that performs the step of transmitting in the DL, e.g., according to the second device aspect and/or any one of the embodiments described herein below, optionally in combination.

The reference resource transmitting module 202 may transmit on a reference resource comprising a group of DL PRBs of the NB channel to the radio device. The CQI report receiving module 204 may receive, based on a measurement of the reference resource, a report from the radio device, the report being indicative of a CQI index of the CQI for which a TB occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NPDSCH TB, the radio scheme comprising 16-QAM as a modulation scheme

Any of the modules of the device 200 may be implemented by units configured to provide the corresponding functionality.

The device 200 may also be referred to as, or may be embodied by, the network node (or base station). The network node 200 and the radio device may be in direct radio communication, e.g., during the receiving and the transmitting. The radio device may be embodied by the device 100.

Fig. 3 shows an example flowchart for a method 300 of reporting a channel quality indicator (CQI) of a narrowband channel between a radio device and a network node in a radio network, e.g., according to the first method aspect.

In a step 302, a reference resource comprising a group of DL PRBs of the NB channel from the network node is measured at the radio device. In a step 304, a CQI index of the CQI for which a TB occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold is derived based on the measuring, wherein the TB is a NPDSCH TB, the radio scheme comprising 16-QAM as a modulation scheme. In a step 306, a report is transmitted to the network node, the report being indicative of the derived CQI index.

The method 300 may be performed by the device 100. For example, the modules 102, 104, and 106 may perform the steps 302, 304, and 306, respectively.

Fig. 4 shows an example flowchart for a method 400 of receiving a channel quality indicator (CQI) of a narrowband channel between a radio device and a network node in a radio network, e.g., according to the second method aspect.

In a step 402, the network node transmits on a reference resource comprising a group of DL PRBs of the NB channel to the radio device. In a step 404, the network node receives, based on a measurement of the reference resource, a report from the radio device, the report being indicative of a CQI index of the CQI for which a TB occupying the reference resource with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NPDSCH TB, the radio scheme comprising 16-QAM as a modulation scheme. In a step 406, the network node transmits in the DL on the narrowband channel using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

The method 400 may be performed by the device 200. For example, the modules 202, 204, and 206 may perform the steps 402, 404, and 406, respectively.

Each of the device 100 and the device 200 may be a radio device (e.g., UE) or a network node (e.g., base station). Herein, any radio device may be a mobile or portable station and/or any radio device wirelessly connectable to a base station or RAN, or to another radio device. For example, the radio device may be a user equipment (UE), a device for machine-type communication (MTC) or a device for (e.g., narrowband) Internet of Things (loT). Two or more radio devices may be configured to wirelessly connect to each other, e.g., in an ad hoc radio network or via a 3GPP SL connection. Furthermore, any base station may be a station providing radio access, may be part of a radio access network (RAN) and/or may be a node connected to the RAN for controlling the radio access. For example, the base station may be an access point, for example a Wi-Fi access point. Herein, whenever referring to noise or a signal-to-noise ratio (SNR), a corresponding step, feature or effect is also disclosed for noise and/or interference or a signal-to-interference-and-noise ratio (SINR).

Fig. 5 schematically illustrates a radio network 500 (e.g., an exemplary network environment) for implementing embodiments of the radio device 100 and the network node 200.

Embodiments of the radio device 100 may comprise tools for monitoring infrastructure (e.g., for freshwater and electricity) or smart buildings. Each of the radio devices 100 is in radio communication using the narrowband channel 502 with at least one of the network nodes 200 of the radio network 500.

The downlink (DL) channel quality may be defined as the NPDCCH repetition level of hypothetical NPDCCH BLER of 1%, e.g., as the predefined threshold for the TB error probability.

Embodiments of the technique can address a 3GPP Work Item (Wl) entitled "Rel- 17 enhancements for NB-loT and LTE-MTC", which was agreed (according to the 3GPP document RP-193264 and which was further updated in the 3GPP document RP-201306. In the Work Item Description (WID) one of the objectives states the following:

• Specify 16-QAM for unicast in UL and DL, including necessary changes to DL power allocation for NPDSCH and DL TBS. This is to be specified without a new NB-loT UE category. For DL, increase in maximum TBS of e.g. 2x the Rel-16 maximum, and soft buffer size will be specified by modifying at least existing Category NB2. For UL, the maximum TBS is not increased.

The main objective above is accompanied by the following sub-item: o Extend the NB-loT channel guality reporting based on the framework of Release 14 to 16, to support 16-QAM in DL.

Embodiments of the technique can meet the above sub-item. The step 306 of transmitting the report and the step 404 of receiving the report (e.g., the report of NB-loT channel quality) may be implemented in IDLE mode and/or during a random access procedure.

Fig. 6 schematically illustrates a DL channel quality reporting in IDLE mode. The device 100 may perform the measuring step 302 on the reference resource 602. The random access is initiated with the device 100 transmitting a random access preamble 604 on the NB-loT random access channel (NPRACH). The NB-loT device 100 may report the DL channel quality according to the step 306 in the MSG3 608 in the IDLE mode:

The DL channel quality on anchor carrier is derived based on DL signal measurement before NPRACH (e.g. NRSRP) at reference sign 602 or on the period the UE receives Random Access Response (RAR) 606. DL channel quality on nonanchor is derived based only on RAR 606 reception period.

Alternatively or in addition, the step 306 of transmitting the report and the step 404 of receiving the report (e.g., the report of NB-loT channel quality) may be implemented in CONNECTED mode.

Fig. 7 schematically illustrates a DL channel quality reporting in CONNECTED mode. The NB-loT device 100 may report the DL channel quality according to the step 306 with a MAC CE 704 in CONNECTED mode. The DL channel quality on a configured carrier may be derived in the step 304 based on an uplink (UL) grant reception period as an example of the reference resource 702.

The reported values for NB-loT are based on an 8-bit mapping table including the following NPDCCH repetition levels (1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048).

The 3GPP document TS 36.133, version 16.6.0, contains descriptions associated to the channel quality reporting in the following clauses:

Any embodiment may implement at least one of the following features of Clause 6.6.2.6 (idle-mode) of the 3GPP document TS 36.133, version 16.6.0: 6.6.2.6 MSG3-based channel quality report for UE Category NB1

The requirements in this clause shall apply for UE supporting DL channel quality reporting for UE Category NB1 as defined in TS 36.331, section 5.3.3.3, 5.3.3.3a, and 5.3.7.4.

The DL channel quality provides the serving eNB with information about the minimum NPDCCH repetition level to satisfy the hypothetical NPDCCH block error rate of 1% with the parameters specified in Table 6.6.2.6-1.

Table 6.6.2.6-1: NPDCCH transmission parameters for downlink quality reporti ng.

For channel quality reporting in the anchor carrier, the reported NPDCCH repetition level shall be derived from the channel quality measured in the period T1 or T2 in the carrier where the random access response is transmitted, wherein

- T1 is the period before NPRACH transmission used for NRSRP measurement for enhanced coverage level estimation; and/or

- T2 is the period from the beginning of the random access response to the beginning of PUSCH format 1 for DL channel quality reporting.

For channel quality reporting in the non-anchor carrier, the reported NPDCCH repetition level shall be derived from the channel quality measured in the period T2 in the carrier where UE monitors Random Access Response where T2 is defined above.

The NPDCCH repetition level for CQI-NPDCCH-NB and CQI-NPDCCH-Short-NB is chosen from the supported NPDCCH repetition levels. The report mapping is defined in clause 9.1.22.15.

The UE shall satisfy the downlink channel quality measurement accuracy requirements as specified in clause 9.1.22.16.

Alternatively or in addition, any embodiment may implement at least one of the following features of Clause 8.14.4 (connected-mode) of the 3GPP document TS 36.133, version 16.6.0:

8.14.4 Connected mode channel quality report for UE Category NB1

The requirements in this clause shall apply for UE supporting DL channel quality reporting for UE Category NB1 as defined in TS 36.331 [2] section TBD when triggered by the MAC-CE command as specified in TS 36.321 [17] section 5.xx.

The DL channel quality provides the serving eNB with information about the minimum NPDCCH repetition level to satisfy the hypothetical NPDCCH block error rate of 1% with the parameters specified in Table 8.14.4-1.

Table 8.14.4-1: NPDCCH transmission parameters for downlink quality reporting

The reported NPDCCH repetition level shall be derived from the channel quality measured over the NPDCCH period which carries the uplink grant of channel quality report for measurement of DL channel quality of the configured carrier.

The NPDCCH repetition level for Quality Report specified in the 3GPP TS 36.321, e.g., version 16.0.0, is chosen from the supported NPDCCH repetition levels. The report mapping is defined in 9.1.22.15. The UE shall satisfy the downlink channel quality measurement accuracy requirements as specified in 9.1.22.16.

Alternatively or in addition, any embodiment may implement at least one of the following features of Clause 9.1.22.15 (report mapping) of the 3GPP document TS 36.133, version 16.6.0:

9.1.22.15 MSG3-based Measurement Report Mapping for UE Category NB1

Table 9.1.22.15-1: Downlink channel quality measurement report mapping of CQI- N PDCCH-NB when the DL channel quality reporting is supported

The NPDCCH repetition level for CQI-NPDCCH-Short-NB is chosen with regard to the signalled parameter Rmax, the maximum number of repetitions for NPDCCH common search space for random access response (npdcch-NumRepetitions-RA) in SystemlnformationBlockType2-NB. The report mapping is defined in Table 9.1.22.15-2.

Table 9.1.22.15-2: Downlink channel quality measurement report mapping of CQI-NPDCCH-Short-NB when the DL channel quality reporting is supported

Alternatively or in addition, any embodiment may implement at least one of the following features of Clause 9.1.22.16 (measurement accuracy requirements) of the 3GPP document TS 36.133, version 16.6.0:

9.1.22.16 Downlink Channel Quality Measurement Accuracy for UE Category NB1

The requirements for accuracy of downlink channel quality reporting in this clause apply only to the serving cell on the anchor carrier for UE Category NB1. The accuracy requirements in Table 9.1.22.16-1 are valid under the following conditions:

Cell specific reference signals are transmitted either from one or two ports.

Conditions defined in TS 36.101 [5] Clause 7.3 for reference sensitivity are fulfilled.

NRSRP | dBm according to Annex B.3.25 for a corresponding Band.

Table 9.1.22.16-1: Downlink channel quality reporting accuracy for UE Category NB1

One important aspect on the clauses above is that although the 3GPP TS 36.133 explicitly refers to "UE Category NB1", in the same technical specification in clause 3.6.1 there is an applicability rule mentioning that the "Following requirements are applicable to UE category NB2".

Embodiments of the technique may be implemented by introducing a NB-loT channel quality reporting for 16-QAM in DL. Accordingly, at least some embodiments can achieve at least the following one of the objectives in the Wl on "Additional enhancements for NB-loT and LTE-MTC", which is to "Specify 16-QAM for unicast in UL and DL", which includes to "Extend the NB-loT channel quality reporting based on the framework of Release 14 to 16, to support 16-QAM in DL".

Embodiments of the technique can achieve at least one of the following requirements. A first requirements in the WID states "Extend the NB-loT channel quality reporting based on the framework of Release 14 to 16, to support 16-QAM in DL" , thus the channel quality reporting for 16-QAM in DL cannot be a completely brand-new design, and it should preferably be backwards compatible. A Second requirement is a proper metric for the CQI reporting (i.e., the nature of the CQI thresholds).

An embodiment may comprise, alone or in combination with the above- mentioned embodiments of each of the aspects, methods for introducing channel quality reporting towards the support of 16-QAM for unicast in DL for NB-loT.

For example, the channel quality reporting to support 16-QAM in DL may be introduced through at least one of the following changing steps.

In a first changing step, the CQI reporting definition for the support of 16-QAM for unicast in DL is based on an existing definition, e.g., for LTE-MTC in the 3GPP document TS 36.213, clause 7.2.3. In a second changing step, the CQI mapping table in thee 3GPP document TS 36.133, clause 9.1.22.15 is used as a baseline to introduce the reporting for 16-QAM in DL through 3 unused combinations found in the above mentioned CQI mapping table. In a third changing step, the channel quality reporting for 16-QAM in DL is created through defining 3 ranges using thresholds based on achievable code rate, which are associated with (or under the umbrella of) an NPDCCH repetition level equal to 1.

In the following embodiments, these three changing steps are explained to arrive at a technique for channel quality reporting that support 16-QAM in the DL of the narrowband channel.

In the 3GPP document TS 36.213, version 16.2.0, clause 7.2.3, the following CQI reporting definition can be found for LTE-MTC:

- A single PDSCH transport block with a combination of modulation scheme and transport block size corresponding to the CQI index, and occupying a group of downlink physical resource blocks termed the CSI reference resource, could be received with a transport block error probability not exceeding 0.1.

Towards the support of the channel quality reporting for 16-QAM in DL, in a first embodiment of NB-loT, above definition for the derived CQI index may be changed (i.e., modified). For example, the definition for the derived CQI index (e.g., the criterion to be fulfilled by the smallest possible CQI index being the derived CQI index) may read:

- A single NPDSCH transport block with a combination of modulation scheme and transport block size corresponding to CQI-NPDCCH-NB in Table 9.1.22.15-1, and occupying a group of downlink physical resource blocks termed the CSI reference resource, could be received with a transport block error probability not exceeding 0.1.

In a first variant of the first embodiment, the CSI reference resource is Narrowband Reference Signal (NRS).

In a second variant of the first embodiment (which may be combined with the first variant), the CSI reference resource can be any other downlink reference signal.

In any embodiment, the radio scheme corresponding to the CQI index may be mapped to the CQI index, e.g., by means of at least one CQI mapping table. The step of deriving 304 may use the mapping to determine the radio schemes corresponding to the respective CQI indices.

The mapping may map the set of CQI indices to the radio schemes corresponding to the respective CQI indices. The radio scheme may be at least partially defined by the mapping. For example, the mapping may define the modulation scheme to be a 16-QAM in the first subset of the set of CQI indices. In the second subset of the set of CQI indices, the modulation scheme may be left undefined by the mapping.

For example, the CQI mapping table in the 3GPP document TS 36.133, clause 9.1.22.15, version 16.6.0 may be used as a baseline to introduce the channel quality reporting for 16-QAM in DL.

Due that a high modulation order as 16-QAM requires good radio conditions, as initial design criteria we limit the case where the "NPDCCH repetition level" is equal to one ("1").

Moreover, the CQI mapping table in TS 36.133 clause 9.1.22.15 currently uses 13 out of 16 entries, which opens the possibility of using 3 entries for the support of the channel quality reporting of 16-QAM in DL. In a second embodiment, which may be combined with the first embodiment, the channel quality reporting for 16-QAM in DL is built based on an "NPDCCH repetition level" equal to 1, which is associated with 3 different subcases built on the 3 unused entries (or combinations) of the CQI mapping table in the 3GPP document TS 36.133, clause 9.1.22.15.

In third embodiment, which may be combined with the first and/or second embodiment, the channel quality reporting for 16-QAM in DL is built based on an "NPDCCH repetition level" equal to 1 or a higher value, which is associated with 3 different subcases or a subset of such subcases built on the 3 unused entries/combinations of the CQI mapping table in the 3GPP document TS 36.133, version 16.6.0, clause 9.1.22.15.

In a first variant of the second and/or third embodiment, the 3 different subcases built on the 3 unused entries and/or unused combinations of the CQI mapping table in the 3GPP document TS 36.133, version 16.6.0, clause 9.1.22.15 correspond to 3 different regions of transport blocks that are suitable to be chosen for a subsequent DL transmission using 16-QAM.

Optionally, to determine the 3 different regions of transport blocks that, e.g., in accordance with the channel quality reporting, are suitable to be chosen for a subsequent DL transmission using 16-QAM as the modulation scheme, a set of thresholds may be introduced, e.g., as described hereinbelow.

In any embodiment, the CQI indices for the CQI reporting in the first subset may be defined or delimited by range thresholds (briefly: thresholds) for a metric of the narrowband channel.

For the second and/or third embodiment, it has been mentioned that the channel quality reporting for 16-QAM in DL would be based on an "NPDCCH repetition level" equal to, e.g., one ("1"), which would have associated 3 different subcases pointing to 3 different regions of transport blocks that would be suitable to be chosen for a subsequent DL transmission using 16-QAM.

In a fourth embodiment, which may be combined with any of the first to third embodiments, the 3 different regions are determined through the thresholds, e.g., using as a metric the achievable code rates of the transport blocks that are selectable for performing DL transmissions using 16-QAM.

In a first variant of the fourth embodiment, the table below is used as an example of a (e.g., full) implementation, in which the changes required to introduce the channel quality reporting for the support of 16-QAM in DL have been printed in italic font relative to the CQI mapping table in clause 9.1.22.15 of the 3GPP document TS 36.133, version 16.6.0. Table 9.1.22.15-1: Downlink channel quality measurement report mapping of CQI-NPDCCH-NB when the DL channel quality reporting is supported

In a second variant of the fourth embodiment (which may be combined with the first variant), the thresholds A, B, and C correspond to fractional numbers associated to the achievable codes (e.g., code rates and/or transport block sizes) of transports blocks (TBs) that are selectable for performing DL transmissions using the 16-QAM as the modulation scheme of the radio scheme. The thresholds may be 0.0 < C < B < A < 1.0. In a third variant of the fourth embodiment (which may be combined with the first and/or second variant), the thresholds A, B, and C correspond to fractional numbers that depend on whether the NB-loT deployment corresponds to a guard-band, stand-alone, or in-band deployment.

In a fourth variant of the fourth embodiment (which may be combined with any of the first to third variants), the thresholds A, B and C correspond to fractional numbers that depend on enhanced coverage level if the report is provided during random access procedure including but not limited to the features named early data transmission (EDT), and/or preconfigured uplink resources (PUR).

For the second and/or third embodiment, e.g., as mentioned above, the channel quality reporting for 16-QAM in DL is built based on an "NPDCCH repetition level" equal to 1 or a higher value.

In a first variant of a fifth embodiment, which may be combined with any one of the first to fourth embodiments), the NPDCCH repetition level 1 is associated with one 16-QAM subcase using code rates greater than D, and NPDCCH repetition level 2 is associated with two 16-QAM subcases using code rates equal to or less than D but greater than E, and equal to or less than E but greater than F, respectively.

In a second variant of the fifth embodiment (which may be combined with the first variant), the NPDCCH repetition level 1 is the one associated with two 16- QAM subcases (e.g., associated with two different CQI indices in the first subset), whereas NPDCCH repetition level 2 is associated with one 16-QAM subcase (e.g., associated with one CQI index in the first subset).

In a third variant of the fifth embodiment (which may be combined with the first or second variant), the thresholds D, E and F correspond to fractional numbers associated to the achievable codes of transports blocks that are selectable for performing DL transmissions using 16-QAM.

In a fourth variant of the fifth embodiment (which may be combined with the first, second, or third variant), the thresholds D, E and F correspond to fractional numbers that depend on whether the NB-loT deployment corresponds to a guard-band, stand-alone, or in-band deployment. In a fifth variant of the fifth embodiment (which may be combined with any one of the first to fourth variants), the thresholds D, E and F correspond to fractional numbers that depend on enhanced coverage level (e.g., a level of the coverage enhancement), if the report 608 is provided during the random access procedure, e.g., including but not limited to features named early data transmission (EDT), and/or preconfigured uplink resources (PUR).

In a sixth variant of the fifth embodiment (which may be combined with any one of the first to fifth variants), in terms of narrowband control channel elements (NCCEs) on the NPDCCH, candidateRep-M, candidateRep-N, and candidateRep-0 are used with either NPDCCH Format 1 or NPDCCH Format 0.

In a seventh variant of the fifth embodiment (which may be combined with any one of the first to sixth variants), in terms of NCCEs on the NPDCCH, candidateRep-M, candidateRep-N, and candidateRep-0 are used only with NPDCCH Format O.

The usage of Table 9.1.22.15-1 including the changes (e.g., updates) to introduce the channel quality reporting for the support of 16-QAM in DL can be illustrated through the following example:

Based on the measurements 302 that the UE 100 has performed, the radio conditions are found to be good as to correspond to an NPDCCH repetition level equal to 1. At this point, based on the changed (e.g., updated) Table 9.1.22.15-1, there are four possible candidates for the CQI index to be derived in the step 304: candidateRep-A, candidateRep-M, candidateRep-N, or candidateRep-0

The UE 100 may have an implementation-dependent algorithm (i.e., an algorithm that is not in defined in a 3GPP specification), which allows the UE 100 to determine whether 16-QAM with Code Rates > A or 16-QAM with A > Code Rates > B or 16-QAM with B > Code Rates > C are suitable to be used, or if rather candidateRep-A (i.e., QPSK) should be reported.

If 16-QAM with Code Rates > A was found to be suitable to use, the UE 100 reports 306 to the network node 200 (e.g., an eNodeB) the CQI index "candidateRep-M", which implies two pieces of information. As a first piece of information, 16-QAM could be used by the network node 200 with Code Rates > A. As a second piece of information, the repetition level for both NPDCCH (explicit in the table) and NPDSCH (implicit under the assumption 16-QAM is used only for 1 repetition) is equal to 1. In a variant of any embodiment, the Table 9.1.22.15-1 is changed (e.g., updated) or a statement is added to the specifications to explicitly mention that the repetition level for NPDSCH is equal to 1.

In a variant of any embodiment, if 16-QAM were to be used also for more than 1 repetition, then the Table 9.1.22.15-1 is changed (e.g., updated) to explicitly include e.g., one column for the NPDSCH repetition level.

In a variant of any embodiment, a relation between the NPDCCH repetition level and the NPDSCH repetition level is created through a mapping between these two quantities.

In a variant of any embodiment, the network node 200 (e.g., the eNodeB) receives 404 such a report (e.g., being indicative of "candidateRep-M" in this example) as a recommendation. The network node 200 may be configured to final determine upon the next DL transmission, i.e., the radio scheme used for the transmission 406.

To illustrate further the relationship between the channel quality reporting and the selectable transport blocks for performing DL transmissions using 16-QAM, below, a first example covering "stand-alone and guard-band deployments" and one more covering "in-band deployments" is described below.

The first example may be implemented as a method of channel quality reporting for 16-QAM in DL for "stand-alone" and "guard-band" deployments of the radio network 500.

In the first example, the TBS Table below is assumed to be used by 16-QAM in DL for "stand-alone" and "guard-band" deployments, wherein exemplary changes for implementing 16-QAM are printed in italic font. Table 1: TBS Table to be used by 16-QAM in DL for "stand-alone" and "guardband" deployments

The achievable code rates for the TBS Table to be used by 16-QAM in DL for "stand-alone" and "guard-band" deployments are displayed below, wherein exemplary changes for implementing 16-QAM are printed in italic font.

Table 2: Achievable Code Rates for the TBS Table to be used by 16-QAM in DL for "stand-alone" and "guard-band" deployments

The thresholds in the CQI mapping table displayed below are set as a function of the achievable code rates shown in Table 2.

Table 9.1.22.15-1: Downlink channel quality measurement report mapping of CQI-NPDCCH-NB when the DL channel quality reporting is supported (e.g., as a change to the 3GPP document TS 36.133, version 16.6.0)

A second example may implement the channel quality reporting for 16-QAM in DL for "in-band" deployments. In the second example, the TBS Table below is assumed to be used by 16-QAM in DL for "in-band" deployments, wherein changes for implementing 16-QAM are printed in italic font.

Table 3: TBS Table to be used by 16-QAM in DL for "in-band" deployments

The achievable code rates for the TBS Table to be used by 16-QAM in DL for "in- band" deployments are displayed below, wherein changes for implementing 16- QAM are printed in italic font.

Table 4: Achievable Code Rates for the TBS Table to be used by 16-QAM in DL for "in-band".

The thresholds in the CQI mapping table displayed below are set as a function of the achievable code rates shown in Table 4, wherein changes relative to the 3GPP document TS 36.133, version 16.6.0, are printed in italic font.

Table 9.1.22.15-1: Downlink channel quality measurement report mapping of CQI-NPDCCH-NB when the DL channel quality reporting is supported

In a variant of any embodiment, the CQI index may be reported in a MAC CE. An alternate mechanism of transmitting the report indicative of a CQI index associated with 16-QAM repurposes the reserved bits, e.g., the 2 bits "R", as shown in below "Octet 1" recited from the 3GPP document TS 36.321:

"Quality Report: For an NB-loT UE, the field corresponds to CQI-NPDCCH-NB as defined in TS 36.331. For a BL UE or UE in CE, the field corresponds to DL channel quality report as defined in TS 36.133. The length of the field is 4 bits." According to the Figure 6.1.3.19-1: (labeled DCQR and AS RAI MAC control element) in the 3GPP document TS 36.133, the MAC CE comprises the following octet.

Thus, the unused code points in the 4-bit Quality Report is kept for the future extension of NPDCCH and to report for example: NPDCCH aggregation level etc. But then the reserved bits in MAC CE are used for Quality reporting instead. One advantage is that separate tables for reporting the CQI index of the NPDCCH and the NPDSCH may be used.

The CQI index 00 (i.e., the CQI value 00) can be interpreted as 16-QAM not supported or not possible.

Another option is rather than alternate the reserved MAC bits are used for further complementing the CQI reporting or basically the CQI reporting is extended by 4 code points (2 reserved bits). This can be used if new additions such as to reflect the relation between NPDCCH and NPDSCH repetition levels are desired along with NPDCCH aggregation level. An example is shown below, which may be implemented as an additional mapping table to be included in the 3GPP document TS 36.133, version 16.6.0.

Table 9.1.22.15-X: Extended Downlink channel quality measurement report mapping of CQI-NPDCCH-NB for 16QAM when the DL channel quality reporting is supported

Thus, basically based upon the report (also referred to as feedback) obtained from UE 100 in the step 404 on the repetition level of the NPDCCH and the NPDSCH, the network node 200 or the radio network (e.g., the RAN) may additionally decide to activate 16-QAM or not.

The methods 300 and 400 may further comprise or initiate a step of exchanging the table indication and/or capability of the network node (e.g., eNB capability). The network node 200 need to indicate to the radio device 100 whether the one or more changed or added tables being indicative of CQI for 16-QAM as the MCS are supported or not. This can be done using a RRC message, such as a Msg4 (RRCConnectionSetup) of the random access procedure.

When such an indication for the support of 16-QAM as the MCS is present, the UE 100 supporting 16-QAM shall use the changed or additional tables for deriving the CQI index (e.g., for checking the MCS index) and for demodulation purpose.

Moreover, as a legacy UE will not understand the extensions (i.e., the first subset) in the set CQI indices, those UEs 100 will then use the legacy table.

Hence, the presence or absence of a changed table indication can act implicitly as a capability of the radio network 500 (besides the usage for UE 100), which table should be used. Fig. 8 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises processing circuitry, e.g., one or more processors 804 for performing the method 300 and memory 806 coupled to the processors 804. For example, the memory 806 may be encoded with instructions that implement at least one of the modules 102, 104 and 106.

The one or more processors 804 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 806, radio device functionality. For example, the one or more processors 804 may execute instructions stored in the memory 806. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action.

As schematically illustrated in Fig. 8, the device 100 may be embodied by a radio device 800, e.g., functioning as a (e.g., data receiving) UE. The radio device 800 comprises a radio interface 802 coupled to the device 100 for radio communication with one or more network nodes, e.g., functioning as a transmitting base station or a receiving UE.

Fig. 9 shows a schematic block diagram for an embodiment of the device 200. The device 200 comprises processing circuitry, e.g., one or more processors 904 for performing the method 400 and memory 906 coupled to the processors 904. For example, the memory 906 may be encoded with instructions that implement at least one of the modules 202, 204 and 206.

The one or more processors 904 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 906, network node functionality. For example, the one or more processors 904 may execute instructions stored in the memory 906. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

As schematically illustrated in Fig. 9, the device 200 may be embodied by a network node 900, e.g., functioning as a base station. The network node 900 comprises a radio interface 902 coupled to the device 200 for radio communication with one or more radio devices, e.g., functioning as a transmitting UE.

With reference to Fig. 10, in accordance with an embodiment, a communication system 1000 includes a telecommunication network 1010, such as a 3GPP-type cellular network, which comprises an access network 1011, such as a radio access network, and a core network 1014. The access network 1011 comprises a plurality of base stations 1012a, 1012b, 1012c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1013a, 1013b, 1013c. Each base station 1012a, 1012b, 1012c is connectable to the core network 1014 over a wired or wireless connection 1015. A first user equipment (UE) 1091 located in coverage area 1013c is configured to wirelessly connect to, or be paged by, the corresponding base station 1012c. A second UE 1092 in coverage area 1013a is wirelessly connectable to the corresponding base station 1012a. While a plurality of UEs 1091, 1092 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1012.

Any of the base stations 1012 and the UEs 1091, 1092 may embody the device 100.

The telecommunication network 1010 is itself connected to a host computer 1030, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 1030 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 1021, 1022 between the telecommunication network 1010 and the host computer 1030 may extend directly from the core network 1014 to the host computer 1030 or may go via an optional intermediate network 1020. The intermediate network 1020 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 1020, if any, may be a backbone network or the Internet; in particular, the intermediate network 1020 may comprise two or more sub-networks (not shown).

The communication system 1000 of Fig. 10 as a whole enables connectivity between one of the connected UEs 1091, 1092 and the host computer 1030. The connectivity may be described as an over-the-top (OTT) connection 1050. The host computer 1030 and the connected UEs 1091, 1092 are configured to communicate data and/or signaling via the OTT connection 1050, using the access network 1011, the core network 1014, any intermediate network 1020 and possible further infrastructure (not shown) as intermediaries. The OTT connection 1050 may be transparent in the sense that the participating communication devices through which the OTT connection 1050 passes are unaware of routing of uplink and downlink communications. For example, a base station 1012 need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 1030 to be forwarded (e.g., handed over) to a connected UE 1091. Similarly, the base station 1012 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1091 towards the host computer 1030.

By virtue of the method 200 being performed by any one of the UEs 1091 or 1092 and/or any one of the base stations 1012, the performance or range of the OTT connection 1050 can be improved, e.g., in terms of increased throughput and/or reduced latency. More specifically, the host computer 1030 may indicate to the network node 200 or the radio network 500 or the radio device 100 acting as a relay (e.g., on an application layer) a QoS of the traffic.

Example implementations, in accordance with an embodiment of the UE, base station and host computer discussed in the preceding paragraphs, will now be described with reference to Fig. 11. In a communication system 1100, a host computer 1110 comprises hardware 1115 including a communication interface 1116 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1100. The host computer 1110 further comprises processing circuitry 1118, which may have storage and/or processing capabilities. In particular, the processing circuitry 1118 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 1110 further comprises software 1111, which is stored in or accessible by the host computer 1110 and executable by the processing circuitry 1118. The software 1111 includes a host application 1112. The host application 1112 may be operable to provide a service to a remote user, such as a UE 1130 connecting via an OTT connection 1150 terminating at the UE 1130 and the host computer 1110. In providing the service to the remote user, the host application 1112 may provide user data, which is transmitted using the OTT connection 1150. The user data may depend on the location of the UE 1130. The user data may comprise auxiliary information or precision advertisements (also: ads) delivered to the UE 1130. The location may be reported by the UE 1130 to the host computer, e.g., using the OTT connection 1150, and/or by the base station 1120, e.g., using a connection 1160.

The communication system 1100 further includes a base station 1120 provided in a telecommunication system and comprising hardware 1125 enabling it to communicate with the host computer 1110 and with the UE 1130. The hardware 1125 may include a communication interface 1126 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1100, as well as a radio interface 1127 for setting up and maintaining at least a wireless connection 1170 with a UE 1130 located in a coverage area (not shown in Fig. 11) served by the base station 1120. The communication interface 1126 may be configured to facilitate a connection 1160 to the host computer 1110. The connection 1160 may be direct, or it may pass through a core network (not shown in Fig. 11) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 1125 of the base station 1120 further includes processing circuitry 1128, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 1120 further has software 1121 stored internally or accessible via an external connection.

The communication system 1100 further includes the UE 1130 already referred to. Its hardware 1135 may include a radio interface 1137 configured to set up and maintain a wireless connection 1170 with a base station serving a coverage area in which the UE 1130 is currently located. The hardware 1135 of the UE 1130 further includes processing circuitry 1138, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 1130 further comprises software 1131, which is stored in or accessible by the UE 1130 and executable by the processing circuitry 1138. The software 1131 includes a client application 1132. The client application 1132 may be operable to provide a service to a human or non-human user via the UE 1130, with the support of the host computer 1110. In the host computer 1110, an executing host application 1112 may communicate with the executing client application 1132 via the OTT connection 1150 terminating at the UE 1130 and the host computer 1110. In providing the service to the user, the client application 1132 may receive request data from the host application 1112 and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The client application 1132 may interact with the user to generate the user data that it provides.

It is noted that the host computer 1110, base station 1120 and UE 1130 illustrated in Fig. 11 may be identical to the host computer 1030, one of the base stations 1012a, 1012b, 1012c and one of the UEs 1091, 1092 of Fig. 10, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 11, and, independently, the surrounding network topology may be that of Fig. 10.

In Fig. 11, the OTT connection 1150 has been drawn abstractly to illustrate the communication between the host computer 1110 and the UE 1130 via the base station 1120, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 1130 or from the service provider operating the host computer 1110, or both. While the OTT connection 1150 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 1170 between the UE 1130 and the base station 1120 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1130 using the OTT connection 1150, in which the wireless connection 1170 forms the last segment. More precisely, the teachings of these embodiments may reduce the latency and improve the data rate and thereby provide benefits such as better responsiveness and improved QoS. A measurement procedure may be provided for the purpose of monitoring data rate, latency, QoS and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1150 between the host computer 1110 and UE 1130, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1150 may be implemented in the software 1111 of the host computer 1110 or in the software 1131 of the UE 1130, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 1111, 1131 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1150 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 1120, and it may be unknown or imperceptible to the base station 1120. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer's 1110 measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software 1111, 1131 causes messages to be transmitted, in particular empty or "dummy" messages, using the OTT connection 1150 while it monitors propagation times, errors etc.

Fig. 12 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 10 and 11. For simplicity of the present disclosure, only drawing references to Fig. 12 will be included in this paragraph. In a first step 1210 of the method, the host computer provides user data. In an optional substep 1211 of the first step 1210, the host computer provides the user data by executing a host application. In a second step 1220, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 1230, the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional fourth step 1240, the UE executes a client application associated with the host application executed by the host computer. Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 10 and 11. For simplicity of the present disclosure, only drawing references to Fig. 13 will be included in this paragraph. In a first step 1310 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In a second step 1320, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step 1330, the UE receives the user data carried in the transmission.

Alternatively or in addition, a technique according to any one of the following embodiments is disclosed.

Embodiment 1. A method (300) of reporting a channel quality indicator, CQI, of a narrowband channel (502) between a radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), the method (300) comprising or initiating the steps of: measuring (302), at the radio device (100; 800; 1091; 1092; 1130), a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the narrowband channel (502) from the network node (200; 900; 1012; 1120); deriving (304), based on the measuring (302), a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmitting (306) a report (608; 704) to the network node (200; 900; 1012; 1120), the report (608; 704) being indicative of the derived CQI index.

The transport block error probability may be a block error rate (BLER).

The radio network may be Low Power Wide Area Network (LPWAN).

Embodiment 2. The method (300) of embodiment 1, wherein the CQI index is derived out of a set of CQI indices, and wherein the derived CQI index is the greatest CQI index out of the set of CQI indices, for which the TB is receivable using the radio scheme corresponding to the CQI index with the transport block error probability equal to or less than the predefined threshold.

The radio device may derive, e.g., for each CQI value, the greatest (i.e., highest) CQI index in the set which satisfies the condition that the transport block error probability is equal to or less than the predefined threshold. If the radio scheme (e.g., the combination) corresponding to the least CQI index (e.g., the index "1" or the first index in the predefined table) does not fulfil the condition, the report may be indicative of a CQI index equal to zero ("0") and/or may be indicative of the absence of a measurement ("no measurement).

Herein, those CQI indices for which the radio schemes corresponding to the respective CQI indices comprise the 16-QAM as the modulation scheme may also be referred to as CQI indices associated with (e.g., mapped to) the 16-QAM. The CQI indices associated with the 16-QAM may be referred to as a first subset in the set (e.g., the set of all CQI indices). Embodiment 3. The method (300) of embodiment 1 or 2, wherein the reference resource (602; 606; 702) is a CSI reference resource (602; 606; 702) or a reference resource (602; 606; 702) for channel state information, CSI, of the narrowband channel (502).

Embodiment 4. The method (300) of any one of embodiments 1 to 3, wherein the method (300) is performed by the radio device (100; 800; 1091; 1092; 1130).

The radio device may be a UE Category NB1.

Embodiment 5. The method (300) of any one of embodiments 1 to 4, wherein the TB using the radio scheme corresponding to the CQI index is receivable at the radio device (100; 800; 1091; 1092; 1130) with the transport block error probability equal to or less than the predefined threshold.

Embodiment 6. The method (300) of any one of embodiments 1 to 5, wherein the narrowband channel (502) comprises one or more physical channels, optionally at least one of a Narrowband internet-of-things, NB-loT, Physical DL Control Channel, NPDCCH; and a NB-loT Physical DL Shared Channel, NPDSCH.

Embodiment 7. The method (300) of any one of embodiments 1 to 6, wherein the radio device (100; 800; 1091; 1092; 1130) is a Narrowband Internet-of-Things, NB-loT, radio device (100; 800; 1091; 1092; 1130) and/or a radio device (100; 800; 1091; 1092; 1130) with Bandwidth reduced Low complexity, BL.

Embodiment 8. The method (300) of any one of embodiments 1 to 7, wherein at least one of the radio device (100; 800; 1091; 1092; 1130), the network node (200; 900; 1012; 1120), and the narrowband channel (502) between the radio device (100; 800; 1091; 1092; 1130) and the network node (200; 900; 1012; 1120) is configured for coverage enhancement, optionally including repetitions of the TB according to a repetition level.

The coverage enhancement may comprise and/or the repetition level may be indicative of more than 10 or more than 100 repetitions of the TP.

Embodiment 9. The method (300) of any one of embodiments 1 to 8, wherein the CQI index corresponds to or is indicative of a repetition level on the narrowband channel (502), optionally on the NPDCCH and/or for the TB.

Embodiment 10. The method (300) of any one of embodiments 1 to 9, wherein the TB is a NPDSCH TB or a NPPCCH TB, and/or wherein the CQI index is derived for the TB being receivable on a NPDSCH and/or for the TB being receivable on a NPDCCH.

Embodiment 11. The method (300) of any one of embodiments 1 to 10, wherein the TB is a single TB, and/or wherein the transport block error probability of the TB relates to the probability of a single TB being receivable.

The TB may be receivable with the block error probability equal to or less than the predefined threshold when using the radio scheme (e.g., the combination of the modulation scheme and the TBS) corresponding to the derived CQI index. Alternatively or in addition, the report may be indicative of a reference number of repetitions.

Embodiment 12. The method (300) of any one of embodiments 1 to 11, wherein the predefined threshold is 0.1 or 0.01 or between 0.1 and 0.01.

Embodiment 13. The method (300) of any one of embodiments 1 to 12, wherein the narrowband channel (502) is a narrowband internet-of-things, NB-loT, channel, and/or the radio device (100; 800; 1091; 1092; 1130) is a NB-loT device.

Alternatively or in addition, the radio network may use a radio access technology (RAT) for the NB-loT. Embodiment 14. The method (300) of any one of embodiments 1 to 13, wherein a bandwidth of the narrowband channel (502) is equal to or less than 180 kHz, and/or wherein the narrowband channel (502) is a half-duplex channel.

Embodiment 15. The method (300) of any one of embodiments 1 to 14, wherein the reference resource (602; 606; 702) is or comprises a reference signal, RS, optionally a DL RS and/or a narrowband reference signal, NRS.

Embodiment 16. The method (300) of any one of embodiments 1 to 15, wherein the radio scheme comprises a combination of the modulation scheme and a transport block size, TBS.

Embodiment 17. The method (300) of any one of embodiments 1 to 16, wherein the radio scheme comprises a combination of the modulation scheme and the repetition level.

Embodiment 18. The method (300) of any one of embodiments 1 to 17, wherein the modulation scheme comprises a modulation and coding scheme, MCS.

Embodiment 19. The method (300) of embodiment 18, wherein the modulation scheme or the MCS apply to the NPDSCH of the narrowband channel (502).

Embodiment 20. The method (300) of any one of embodiments 1 to 19, wherein a mapping maps the derived CQI index or each CQI index or each CQI index in the set of CQI indices to the radio scheme corresponding to the respective CQI index.

Embodiment 21. The method (300) of embodiment 20, wherein the mapping comprises or is implemented by at least one predefined mapping table.

The at least one predefined table may, for each CQI index in the set of CQI indices, be indicative of the combination of the modulation scheme and the repetition level corresponding to the respective CQI index.

Embodiment 22. The method (300) of embodiment 20 or 21, wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 1 or greater than 1.

The mapping or the at least one predefined mapping table may be indicative of the 16-QAM as the modulation scheme in combination with the repetition level being equal to or less than 16 or 32 or 64. Embodiment 23. The method (300) of any one or embodiments 20 to 22, wherein the mapping, optionally the same predefined mapping table, maps each CQI index in a first subset of the set of CQI indices to the radio scheme comprising 16-QAM as the modulation scheme and further maps each CQI index in a second subset of the set of CQI indices to the radio scheme corresponding to the respective CQI index.

The second subset may be disjoint from the first subset. The respective radio schemes corresponding to the CQI indices in the second subset may comprise a modulation scheme other than the 16-QAM.

Embodiment 24. The method (300) of embodiment 23, wherein each CQI index in the second subset is less than each CQI index in the first subset.

Embodiment 25. The method (300) of embodiment 23 or 24, wherein each CQI index in the second subset corresponds to a channel quality of the narrowband channel (502) lesser than the channel quality of the narrowband channel (502) of each CQI index in the first subset.

Embodiment 26. The method (300) of any one or embodiments 23 to 25, wherein each or at least one of the respective radio schemes corresponding to the CQI indices in the second subset comprises quadrature phase-shift keying, QPSK, or binary phase-shift keying, BPSK, as the modulation scheme and/or a repetition level equal to or greater than 1.

The set may comprise a number of N=2ⁿ or N=2ⁿ-1 CQI indices for an integer n (e.g., n=4). The first subset may comprise a number of Ni CQI indices and the second subset may comprise a number of /V₂ CQI indices, wherein N = N + /V₂. For example, N = 13 and /V₂ = 3.

Embodiment 27. The method (300) of any one or embodiments 23 to 26, wherein different CQI indices in the first subset correspond to different ranges of a code rate of the respective radio scheme. Optionally, the modulation scheme column or a further column (e.g., a code rate column) of the at least one predefined mapping table may be indicative of the ranges of the code rate.

The radio scheme may comprise or define the code rate. Alternatively or in addition, the code rate may be achievable by the TB using the radio scheme.

The different ranges of the code rate may be pairwise disjoint.

Embodiment 28. The method (300) of any one or embodiments 23 to 27, wherein the radio scheme comprises a TBS of the TB, and wherein different CQI indices in the first subset correspond to different ranges of a TBS of the TB with the respective radio scheme.

The different ranges of the TBS may be pairwise disjoint.

Embodiment 29. The method (300) of embodiment 27 or 28, wherein the ranges are defined or delimited by range thresholds.

Embodiment 30. The method (300) of embodiment 29, wherein the range thresholds correspond to fractional numbers of achievable code rates of the TB using the respective radio schemes.

Embodiment 31. The method (300) of embodiment 29 or 30, wherein the ranges or the range thresholds depend on whether the radio network (500; 1010) is a guard-band deployment, a stand-alone deployment, or an in-band deployment.

Embodiment 32. The method (300) of any one of embodiments 29 to 31, wherein the ranges or the range thresholds depend on a level of a coverage enhancement on the narrowband channel (502). The level of the coverage enhancement (also: coverage enhancement level) may comprise a number of repetitions of the TB. The repetition level may be an example of the coverage enhancement level.

Embodiment 33. The method (300) of any one of embodiments 27 to 32, wherein greater CQI indices in the first subset correspond to the ranges having greater values of the code rate or the TBS.

In other words, the ranges may be sorted in ascending order of the CQI index. Alternatively, the lesser CQI indices in the first subset may correspond to the ranges having greater values of the code rate or the TBS. In other words, the ranges may be sorted in descending order of the CQI index.

Embodiment 34. The method (300) of any one of embodiments 23 to 33, wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 1 for a first CQI index in the first subset, and/or wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 2 for a second CQI index and a third CQI index in the first subset.

Embodiment 35. The method (300) of any one of embodiments 23 to 34, wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 1 for a first CQI index and a second CQI index in the first subset, and/or wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with the repetition level being 2 for a third CQI index in the first subset.

Embodiment 36. The method (300) of embodiment 34 or 35, wherein the first CQI index in the first subset corresponds to a first range of the code rate, wherein the second CQI index in the first subset corresponds to a second range of the code rate, and wherein the third CQI index in the first subset corresponds to a third range of the code rate.

Herein, the range thresholds of the first, second, and third ranges may also be referred to as E, F, and G, respectively. Embodiment 37. The method (300) of any one of embodiments 23 to 36, the narrowband channel (502) comprising a NB-loT Physical DL Control Channel, NPDCCH, comprising narrowband control channel elements, NCCEs, wherein the radio schemes corresponding to the CQI indices in the first subset are used in the NCCEs with either NPDCCH Format 0 or NPDCCH Format 1.

Embodiment 38. The method (300) of any one of embodiments 23 to 36, the narrowband channel (502) comprising a NB-loT Physical DL Control Channel, NPDCCH, comprising narrowband control channel elements, NCCEs, wherein the radio schemes corresponding to the CQI indices in the first subset are used in the NCCEs only with NPDCCH Format 0.

The report may be a CSI feedback.

Embodiment 39. The method (300) of any one of embodiments 1 to 38, wherein the report (608) is, or is transmitted in, a message of a random access, RA, procedure, optionally in a Message 3, Msg3, of the RA procedure or an Early Data Transmission, EDT, of the RA procedure; and/or wherein the report (608; 704) is or is transmitted in a preconfigured uplink resource, PUR.

Embodiment 40. The method (300) of any one of embodiments 1 to 39, wherein the report (704) is, or is transmitted in, a medium access control, MAC, packet data unit, PDU, or a MAC control element, MAC CE.

Embodiment 41. The method (300) of any one of embodiments 1 to 40, wherein the report (608; 704) comprises a bit field that is indicative of the CQI index, optionally the bit field comprising 4 bits.

Embodiment 42. The method (300) of embodiment 41, wherein the MAC CE comprises a bit field that is indicative of the CQI index, optionally the bit field comprising 6 bits.

The bit field may correspond to CQI-NPDCCH-NB as defined in the 3GPP document TS 36.331, version 16.1.1. Embodiment 43. The method (300) of any one of embodiments 23 to 42, wherein consecutive 4 bits in the bit field are configured to represent the CQI indices in the second subset of the set of CQI indices, and/or wherein 2 bits in the bit field outside of the consecutive 4 bits are configured to represent the CQI indices in the first subset of the set of CQI indices.

Embodiment 44. The method (300) of embodiment 43, wherein the bit field is representative of the CQI indices in the second subset if 2 bits in the bit field outside of the consecutive 4 bits are zero; and/or wherein the bit field is representative of the CQI indices in the first subset if at least one bit in the bit field outside of the consecutive 4 bits is non-zero.

Embodiment 45. The method (300) of any one of embodiments 20 to 44, wherein the mapping comprises or is implemented by a first mapping table that is indicative of the CQI index for the NPDCCH of the narrowband channel (502) and a second mapping table that is indicative of the CQI index for the NPDSCH of the narrowband channel (502).

Embodiment 46. The method (300) of any one of embodiments 1 to 45, further comprising or initiating the step of: receiving a radio resource control, RRC, message indicative of whether or not the network node (200; 900; 1012; 1120) or the radio network (500; 1010) supports 16-QAM as the modulation scheme on the narrowband channel (502).

Embodiment 47. A method (400) of receiving a channel quality indicator, CQI, of a narrowband channel (502) between a radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), the method (400) comprising or initiating the steps of: transmitting (402) on a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the narrowband channel (502) to the radio device (100; 800; 1091; 1092; 1130); receiving (404), based on a measurement of the reference resource (602; 606; 702), a report (608; 704) from the radio device (100; 800; 1091; 1092; 1130), the report (608; 704) being indicative of a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; transmitting (406) in the DL on the narrowband channel (502) using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

Embodiment 48. The method (400) of embodiment 47, wherein the method (400) is performed by the network node (200; 900; 1012; 1120).

Embodiment 49. The method (400) of embodiment 47 or 48, further comprising any feature or step of any one of embodiments 2 to 46 or a feature or step corresponding thereto.

Embodiment 50. A computer program product comprising program code portions for performing the steps of any one of the embodiments 1 to 46 or 47 to 49 when the computer program product is executed on one or more computing devices (804; 904), optionally stored on a computer-readable recording medium (806; 906).

Embodiment 51. A radio device (100; 800; 1091; 1092; 1130) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device (100; 800; 1091; 1092; 1130) is operable to perform the steps of any one of embodiments 1 to 46.

Embodiment 52. A radio device (100; 800; 1091; 1092; 1130), configured to perform the steps of any one of embodiments 1 to 46. Embodiment 53. A user equipment, UE, (100; 800; 1091; 1092; 1130) configured to communicate with a base station (200; 900; 1012; 1120) or radio device (100; 800; 1091; 1092; 1130) functioning as a gateway, the UE (100; 800; 1091; 1092; 1130) comprising a radio interface (802; 1137) and processing circuitry (1104; 1438) configured to execute the steps of any one of embodiments 1 to 46.

Embodiment 54. A network node (200; 900; 1012; 1120) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node (200; 900; 1012; 1120) is operable to perform the steps of any one of embodiments 47 to 49.

Embodiment 55. A network node (200; 900; 1012; 1120) configured to perform the steps of any one of embodiments 47 to 49.

Embodiment 56. A base station (200; 900; 1012; 1120) configured to communicate with a user equipment, UE, the base station (200; 900; 1012; 1120) comprising a radio interface (1202; 1427) and processing circuitry (904; 1128) configured to execute the steps of any one of embodiments 47 to 49.

Embodiment 57. A communication system (1000; 1100) including a host computer (1030; 1110) comprising: processing circuitry (1118) configured to provide user data; and a communication interface (1116) configured to forward user data to a cellular or ad hoc radio network (500; 1010) for transmission to a user equipment, UE, (100; 800; 1091; 1092; 1130) wherein the UE (100; 800; 1091; 1092; 1130) comprises a radio interface (802; 1137) and processing circuitry (804; 1138), the processing circuitry (804; 1138) of the UE (100; 800; 1091; 1092; 1130) being configured to execute the steps of any one of embodiments 1 to 46.

Embodiment 58. The communication system (1000; 1100) of embodiment 57, further including the UE (100; 800; 1091; 1092; 1130).

Embodiment 59. The communication system (1000; 1100) of embodiment 57 or 58, wherein the radio network (500; 1010) further comprises a base station (200; 900; 1012; 1120) or radio device (100; 800; 1091; 1092; 1130) functioning as a gateway configured to communicate with the UE (100; 800; 1091; 1092; 1130). Embodiment 60. The communication system (1000; 1100) of embodiment 59, wherein the base station (200; 900; 1012; 1120) or the radio device (100; 800; 1091; 1092; 1130) functioning as a gateway comprises processing circuitry (904; 1128) being configured to execute the steps of any one of embodiments 47 to 49.

Embodiment 61. The communication system (1000; 1100) of any one of embodiments 57 to 60, wherein: the processing circuitry (1118) of the host computer (1030; 1110) is configured to execute a host application (1112), thereby providing the user data; and the processing circuitry (804; 1138) of the UE (100; 800; 1091; 1092; 1130) is configured to execute a client application (1132) associated with the host application (1112).

Any embodiment of the technique may be or may comprise a method for introducing a channel quality reporting towards the support of 16-QAM for unicast in DL for NB-loT.

Alternatively or in addition, the channel quality reporting 306 to support 16-QAM in DL has been introduced through the following steps. The CQI reporting definition for the support of 16-QAM for unicast in DL has been based on an existing definition for LTE-MTC in TS 36.213, clause 7.2.3. The CQI mapping table in TS 36.133, clause 9.1.22.15 has been used as a baseline to introduce the reporting for 16-QAM in DL through 3 unused combinations found in the above mentioned CQI mapping table. The channel quality reporting for 16-QAM in DL has been created through defining 3 ranges using thresholds based on achievable coders, which are under the umbrella of an NPDCCH repetition level equal to 1.

As has become apparent from above description, at least some embodiments of the technique allow for an improved selection of a relay radio device and/or an improved selection of a SL connection establishment. Same or further embodiments can ensure that the traffic relayed by the relay radio device is given the appropriate QoS treatment.

Same or further embodiments can fulfill a design criterion of the Wl Description as to "Extend the NB-loT channel quality reporting based on the framework of Rel-14— 16, to support 16-QAM in DL". Alternatively or in addition, embodiments for the channel quality reporting for 16-QAM in DL is backwards compatible. Alternatively or in addition, to introduce the channel quality reporting for 16- QAM in DL, there is no need to increase the number of bits of the higher layer parameter associated to the CQI mapping table.

Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and/or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following claims.

Claims

1. A method (300) of reporting a channel quality indicator, CQI, of a narrowband, NB, channel (502) between a radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), the method (300) comprising or initiating the steps of: measuring (302), at the radio device (100; 800; 1091; 1092; 1130), a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) from the network node (200; 900; 1012; 1120); deriving (304), based on the measuring (302), a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmitting (306) a report (608; 704) to the network node (200; 900; 1012; 1120), the report (608; 704) being indicative of the derived CQI index.

2. The method (300) of claim 1, wherein the transport block error probability is a block error rate, BLER.

3. The method (300) of claim 1 or 2, wherein the method (300) is applied to a narrowband internet of things, NB-loT, device as the radio device (100; 800; 1091; 1092; 1130) and/or a NB-loT physical DL shared channel, NPDSCH, on the narrowband channel (502).

4. The method (300) of any one of claims 1 to 3, wherein the CQI index is derived (304) for the TB being receivable on a NPDSCH.

5. The method (300) of any one of claims 1 to 4, wherein the CQI index is derived out of a set of CQI indices, and wherein the derived CQI index is the greatest CQI index out of the set of CQI indices, for which the TB is receivable using the radio scheme corresponding to the CQI index with the transport block error probability equal to or less than the predefined threshold. 68

6. The method (300) of any one of claims 1 to 5, wherein the reference resource (602; 606; 702) is a CSI reference resource (602; 606; 702) or a reference resource (602; 606; 702) for channel state information, CSI, of the narrowband channel (502).

7. The method (300) of any one of embodiments 1 to 4, wherein the TB using the radio scheme corresponding to the CQI index is receivable at the radio device (100; 800; 1091; 1092; 1130) with the transport block error probability equal to or less than the predefined threshold.

8. The method (300) of any one of claims 1 to 6, wherein at least one of the radio device (100; 800; 1091; 1092; 1130), the network node (200; 900; 1012; 1120), and the narrowband channel (502) between the radio device (100; 800; 1091; 1092; 1130) and the network node (200; 900; 1012; 1120) is configured for coverage enhancement.

9. The method (300) of any one of claims 1 to 8, wherein the TB is a single TB, and/or wherein the transport block error probability of the TB relates to the probability of a single TB being receivable.

10. The method (300) of any one of claims 1 to 9, wherein the predefined threshold is 0.1 or 0.01 or between 0.1 and 0.01.

11. The method (300) of any one of claims 1 to 10, wherein a single NPDSCH TB of the TB with a combination of the modulation scheme and a transport block size, TBS, corresponding to the CQI index, and occupying the group of DL PRBs termed CSI reference resource as the resource source, is receivable with the transport block error probability not exceeding 0.1.

12. The method (300) of any one of claims 1 to 11, wherein the reference resource (602; 606; 702) comprises at least one of a DL RS and a narrowband reference signal, NRS.

13. The method (300) of any one of claims 1 to 12, wherein the radio scheme comprises a combination of the modulation scheme and a transport block size, TBS. 69

14. The method (300) of any one of claims 1 to 13, wherein the reported CQI index is further indicative of a code rate and/or TBS of the TB.

15. The method (300) of any one of claims 1 to 14, wherein the radio scheme comprises a combination of the modulation scheme and a repetition level.

16. The method (300) of any one of claims 1 to 15, wherein the modulation scheme comprises a modulation and coding scheme, MCS, and wherein the modulation scheme or the MCS apply to the NPDSCH of the narrowband channel (502).

17. The method (300) of any one of claims 1 to 16, wherein a mapping maps the derived CQI index or each CQI index or each CQI index in the set of CQI indices to the radio scheme corresponding to the respective CQI index.

18. The method (300) of claim 17, wherein the mapping comprises or is implemented by at least one predefined mapping table.

19. The method (300) of claim 17 or 18, wherein the mapping or the at least one predefined mapping table is indicative of the 16-QAM as the modulation scheme in combination with a or the repetition level being 1.

20. The method (300) of any one or claims 17 to 19, wherein the mapping, optionally the same predefined mapping table, maps each CQI index in a first subset of the set of CQI indices to the radio scheme comprising 16-QAM as the modulation scheme and further maps each CQI index in a second subset of the set of CQI indices to the radio scheme corresponding to the respective CQI index, wherein the respective radio schemes corresponding to the CQI indices in the second subset comprise a modulation scheme other than the 16-QAM.

21. The method (300) of claim 20, wherein each CQI index in the second subset is less than each CQI index in the first subset.

22. The method (300) of any one or claims 20 or 21, wherein at least one of the respective radio schemes corresponding to the CQI indices in the second subset comprises a repetition level greater than 1. 70

23. The method (300) of any one or claims 20 to 22, wherein different CQI indices in the first subset correspond to different ranges of a code rate of the respective radio scheme.

24. The method (300) of any one or claims 20 to 23, wherein the radio scheme comprises a TBS of the TB, and wherein different CQI indices in the first subset correspond to different ranges of a TBS of the TB with the respective radio scheme.

25. The method (300) of claim 23 or 24, wherein the ranges are defined or delimited by range thresholds.

26. The method (300) of claim 25, wherein the range thresholds correspond to fractional numbers of achievable code rates of the TB using the respective radio schemes.

27. The method (300) of claim 25 or 26, wherein the ranges or the range thresholds depend on whether the radio network (500; 1010) is a guard-band deployment, a stand-alone deployment, or an in-band deployment.

28. The method (300) of any one of claims 1 to 27, wherein the channel quality reporting (306) for 16-QAM in the DL is created through defining 3 ranges using thresholds based on achievable code rates, which are associated with an NPDCCH repetition level equal to 1.

29. The method (300) of any one of claims 23 to 28, wherein greater CQI indices in the first subset correspond to the ranges having greater values of the code rate or the TBS.

30. The method (300) of any one of claims 1 to 29, wherein the report (608) is, or is transmitted in, a message of a random access, RA, procedure, optionally in a Message 3, Msg3, of the RA procedure or an Early Data Transmission, EDT, of the RA procedure; and/or wherein the report (608; 704) is or is transmitted in a preconfigured uplink resource, PUR. 71

31. The method (300) of any one of claims 1 to 30, wherein the report (704) is, or is transmitted in, a medium access control, MAC, packet data unit, PDU, or a MAC control element, MAC CE.

32. The method (300) of any one of claims 1 to 31, wherein the report (608; 704) comprises a bit field that is indicative of the CQI index, optionally the bit field comprising 4 bits.

33. The method (300) of claim 32, wherein the MAC CE comprises a bit field that is indicative of the CQI index, optionally the bit field comprising 6 bits.

34. A method (400) of receiving a channel quality indicator, CQI, of a narrowband, NB, channel (502) between a radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), the method (400) comprising or initiating the steps of: transmitting (402) on a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) to the radio device (100; 800; 1091; 1092; 1130); receiving (404), based on a measurement of the reference resource (602; 606; 702), a report (608; 704) from the radio device (100; 800; 1091; 1092; 1130), the report (608; 704) being indicative of a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmitting (406) in the DL on the narrowband channel (502) using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

35. The method (400) of claim 34, wherein the method (400) is performed by the network node (200; 900; 1012; 1120).

36. The method (400) of claim 34 or 35, further comprising any feature or step of any one of claims 2 to 33 or a feature or step corresponding thereto. 72

37. A computer program product comprising program code portions for performing the steps of any one of the claims 1 to 33 or 34 to 36 when the computer program product is executed on one or more computing devices (804; 904), optionally stored on a computer-readable recording medium (806; 906).

38. A radio device (100; 800; 1091; 1092; 1130) for reporting a channel quality indicator, CQI, of a narrowband, NB, channel (502) between the radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device (100; 800; 1091; 1092; 1130) is operable to: measure, at the radio device (100; 800; 1091; 1092; 1130), a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) from the network node (200; 900; 1012; 1120); derive, based on the measurement, a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit a report (608; 704) to the network node (200; 900; 1012; 1120), the report (608; 704) being indicative of the derived CQI index.

39. The radio device (100; 800; 1091; 1092; 1130) of claim 38, further comprising the features or being operable to perform the steps of any one of claims 2 to 33.

40. A radio device (100; 800; 1091; 1092; 1130) for reporting a channel quality indicator, CQI, of a narrowband, NB, channel (502) between the radio device (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), configured to : measure, at the radio device (100; 800; 1091; 1092; 1130), a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) from the network node (200; 900; 1012; 1120); derive, based on the measurement, a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit a report (608; 704) to the network node (200; 900; 1012; 1120), the report (608; 704) being indicative of the derived CQI index.

41. The radio device (100; 800; 1091; 1092; 1130) of claim 40, further comprising the features or being configured to perform the steps of any one of claims 2 to 33.

42. A user equipment, UE, (100; 800; 1091; 1092; 1130) for reporting a channel quality indicator, CQI, of a narrowband, NB, channel (502) between the UE (100; 800; 1091; 1092; 1130) and a network node (200; 900; 1012; 1120) in a radio network (500; 1010), configured to communicate with a base station (200; 900; 1012; 1120) or radio device (100; 800; 1091; 1092; 1130) functioning as a gateway, the UE (100; 800; 1091; 1092; 1130) comprising a radio interface (802; 1137) and processing circuitry (1104; 1438) configured to: measure, at the UE (100; 800; 1091; 1092; 1130), a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) from the network node (200; 900; 1012; 1120); derive, based on the measurement, a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit a report (608; 704) to the network node (200; 900; 1012; 1120), the report (608; 704) being indicative of the derived CQI index.

43. The UE (100; 800; 1091; 1092; 1130) of claim 42, further comprising the features or being configured to perform the steps of any one of claims 2 to 33.

44. A network node (200; 900; 1012; 1120) for receiving a channel quality indicator, CQI, of a narrowband, NB, channel (502) between a radio device (100; 800; 1091; 1092; 1130) and the network node (200; 900; 1012; 1120) in a radio network (500; 1010), comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node (200; 900; 1012; 1120) is operable to: transmit on a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) to the radio device (100; 800; 1091; 1092; 1130); receive, based on a measurement of the reference resource (602; 606; 702), a report (608; 704) from the radio device (100; 800; 1091; 1092; 1130), the report (608; 704) being indicative of a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit in the DL on the narrowband channel (502) using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

45. The network node (200; 900; 1012; 1120) of claim 44, further comprising the features or being operative to perform the steps of any one of claims 35 to 36.

46. A network node (200; 900; 1012; 1120) for receiving a channel quality indicator, CQI, of a narrowband, NB, channel (502) between a radio device (100; 800; 1091; 1092; 1130) and the network node (200; 900; 1012; 1120) in a radio network (500; 1010), configured to: transmit on a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) to the radio device (100; 800; 1091; 1092; 1130); receive, based on a measurement of the reference resource (602; 606; 702), a report (608; 704) from the radio device (100; 800; 1091; 1092; 1130), the report (608; 704) being indicative of a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB 75 physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit in the DL on the narrowband channel (502) using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

47. The network node (200; 900; 1012; 1120) of claim 46, further comprising the features or being configured to perform the steps of any one of claims 35 to 36.

48. A base station (200; 900; 1012; 1120) for receiving a channel quality indicator, CQI, of a narrowband, NB, channel (502) between a user equipment, UE, (100; 800; 1091; 1092; 1130) and the base station (200; 900; 1012; 1120) in a radio network (500; 1010), configured to communicate with the UE, the base station (200; 900; 1012; 1120) comprising a radio interface (1202; 1427) and processing circuitry (904; 1128) configured to: transmit on a reference resource (602; 606; 702) comprising a group of downlink, DL, physical resource blocks, PRBs, of the NB channel (502) to the UE (100; 800; 1091; 1092; 1130); receive, based on a measurement of the reference resource (602; 606; 702), a report (608; 704) from the UE (100; 800; 1091; 1092; 1130), the report (608; 704) being indicative of a CQI index of the CQI for which a transport block, TB, occupying the reference resource (602; 606; 702) with a radio scheme corresponding to the CQI index is receivable with a transport block error probability equal to or less than a predefined threshold, wherein the TB is a NB physical DL shared channel, NPDSCH, TB, the radio scheme comprising 16 Quadrature Amplitude Modulation, 16-QAM, as a modulation scheme; and transmit in the DL on the narrowband channel (502) using a radio scheme depending on the received CQI index, the used radio scheme comprising 16-QAM as the modulation scheme.

49. The base station (200; 900; 1012; 1120) of claim 48, further comprising the features or being configured to perform the steps of any one of claims 35 to 36. 76

50. A communication system (1000; 1100) including a host computer (1030; 1110) comprising: processing circuitry (1118) configured to provide user data; and a communication interface (1116) configured to forward user data to a cellular or ad hoc radio network (500; 1010) for transmission to a user equipment, UE, (100; 800; 1091; 1092; 1130) wherein the UE (100; 800; 1091; 1092; 1130) comprises a radio interface (802; 1137) and processing circuitry (804; 1138), the processing circuitry (804; 1138) of the UE (100; 800; 1091; 1092; 1130) being configured to execute the steps of any one of claims 1 to 33.

51. The communication system (1000; 1100) of claim 50, further including the UE (100; 800; 1091; 1092; 1130).

52. The communication system (1000; 1100) of claim 50 or 51, wherein the radio network (500; 1010) further comprises a base station (200; 900; 1012; 1120) or radio device (100; 800; 1091; 1092; 1130) functioning as a gateway configured to communicate with the UE (100; 800; 1091; 1092; 1130).

53. The communication system (1000; 1100) of claim 52, wherein the base station (200; 900; 1012; 1120) or the radio device (100; 800; 1091; 1092; 1130) functioning as a gateway comprises processing circuitry (904; 1128) being configured to execute the steps of any one of claims 34 to 36.

54. The communication system (1000; 1100) of any one of claims 50 to 53, wherein: the processing circuitry (1118) of the host computer (1030; 1110) is configured to execute a host application (1112), thereby providing the user data; and the processing circuitry (804; 1138) of the UE (100; 800; 1091; 1092; 1130) is configured to execute a client application (1132) associated with the host application (1112).