WO2021061124A1

WO2021061124A1 - Explicit nack signaling performed in an optional manner suitable for 5g nr urllc performance improvements

Info

Publication number: WO2021061124A1
Application number: PCT/US2019/053068
Authority: WO
Inventors: Anil Rao
Original assignee: Nokia Technologies Oy; Nokia Usa Inc.
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2021-04-01

Abstract

A group of UE(s) is configured with reserved resources, reserved periodically in time and on which the UE(s) can transmit in uplink in one of multiple time slots. A BS determines for which UE(s) of the group there were signals received and decoded, the signals received over the reserved resources in one of the time slots. The BS does nothing for the UE(s) of the group where there were signals received and decoded. In response to there being at least one UE of the group where signals were not received or were received but not decoded, the BS sends a set of indications including indication(s) of NACK to the at least one UE and indication(s) of acknowledgment to all other UE(s) in the group. In response to all UE(s) of the group having signals that were received and decoded, the BS does not send the set of indications.

Description

Explicit NACK Signaling Performed in an Optional Manner Suitable for 5G NR URLLC

Performance Improvements

TECHNICAL FIELD

[0001] This invention relates generally to uplink in a wireless communication system and, more specifically, relates to uplink in Ultra Reliable Low Latency Communications (URLLC) and other communications techniques for high reliability.

BACKGROUND

[0002] The Rel-15 (release 15) Ultra Reliable Low Latency Communications (URLLC) design in 5G NR (fifth generation new radio) aims to achieve a very high reliability level of 99.999% while simultaneously achieving a very low latency of less than 1 millisecond (ms) delay in the RAN (radio access network), where delay includes queuing delay in the RAN plus any over the air transmission delay due to HARQ (Hybrid Automatic Repeat reQuest) retransmissions. The enhancements to URLLC in Rel-16 (release 16) aim to increase the reliability level even further to 99.9999% - 99.999999% (6 nines to 8 nines) and possibly reduce latency even more as described in 3GPP, “Study on physical layer enhancements for NR ultra-reliable and low latency case (URLLC) Release 16”, 3GPP TR 38.824 V2.0.1 (2019-03). This further reduced latency is used to address automation in new vertical domains discussed in 3GPP, “Study for Communication for Automation in Vertical Domains”, 3GPP TR 22.804 V16.2.0 (2018-12).

[0003] These very low latency, highly reliable enhancements require different uplink strategies.

BRIEF SUMMARY

[0004] This section is intended to include examples and is not intended to be limiting.

[0005] In an exemplary embodiment, a method is disclosed that includes configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots. The method includes determining, by the base station, for which user equipment of the group there were signals received and decoded. The signals being received over the reserved resources in a selected one of the plurality of time slots The method further includes doing nothing by the base station for the user equipment of the group where there were signals received and decoded. The method also includes, in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group. The method finally includes, in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications.

[0006] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0007] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; doing nothing by the base station for the user equipment of the group where there were signals received and decoded; in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications. [0008] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; code for determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; code for doing nothing by the base station for the user equipment of the group where there were signals received and decoded; code, in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, for sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and code, in response to all user equipment of the group having signals that were received and decoded, for not sending the set of indications.

[0009] In another exemplary embodiment, an apparatus comprises: means for configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; means for determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; means for doing nothing by the base station for the user equipment of the group where there were signals received and decoded; means, responsive to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, for sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and means, responsive to all user equipment of the group having signals that were received and decoded, for not sending the set of indications.

[0010] In an exemplary embodiment, a method is disclosed that includes receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots. The method includes scanning by the user equipment a resource location for acknowledgement information from the base station. The acknowledgement information is for transmissions performed previous to the scanning in a selected one of the plurality of time slots. The method includes, in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station. The method also includes, in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[0011] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0012] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station; in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[0013] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; code for scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; code, in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, for assuming an implicit acknowledgement has been performed by the base station; code, in response to detecting acknowledgement information, for checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and for performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[0014] In another exemplary embodiment, an apparatus comprises: means for receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; means for scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; means, responsive to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, for assuming an implicit acknowledgement has been performed by the base station; and means, responsive to detecting acknowledgement information, for checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and for performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the attached Drawing Figures:

[0016] FIG. 1 is a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced;

[0017] FIG. 2 illustrates operation for uplink (UL) resource allocation by grant-free configuration and is used to compare operation with Configured Grant (CG) (bottom) and operation without CG (top); [0018] FIG. 3, split into FIGS. 3(a), 3(b), and 3(c), illustrates the following: Current behavior on 3 GPP Rel-15 specification of uplink configured grant when FIG. 3 (a) the gNB detects and decodes transmission successfully, FIG. 3(b) the gNB detects but does not decode transmission successfully, and FIG. 3(c) the gNB misses the detection of the UE transmission;

[0019] FIG. 4, split into FIGS. 4(a), 4(b), and 4(c), illustrates the following: Behavior of “explicit ACK” proposal in Rl- 1900932 when FIG. 4(a) the gNB detects and decodes transmission successfully, FIG. 4(b) the gNB detects but does not decode transmission successfully, and FIG. 4(c) the gNB misses the detection of the UE transmission;

[0020] FIG. 5, split into FIGS. 5(a), 5(b), and 5(c), illustrates the following in an exemplary embodiment: Behavior of “explicit NACK” proposal in an exemplary embodiment when FIG. 5(a) the gNB detects and decodes transmission successfully, FIG. 5(b) the gNB detects but does not decode transmission successfully, and FIG. 5(c) the gNB misses the detection of the UE transmission; and

[0021] FIG. 6, split over FIGS. 6A and 6B, is a signaling and logic flow diagram for explicit NACK signaling performed in an optional manner suitable for 5G NR URLLC performance improvements.

DETAILED DESCRIPTION OF THE DRAWINGS

[0022] The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

[0023] % percent [0024] 3 GPP third generation partnership project [0025] 5G fifth generation [0026] 5GC 5G core network [0027] ACK Acknowledgement/ [0028] AMF access and mobility management function [0029] BS base station [0030] CG Configured Grant [0031] CRC Cyclic Redundancy Check [0032] CU central unit [0033] DCI Downlink Control Information [0034] DL downlink (from RAN node to UE) [0035] DTX Discontinuous Transmission [0036] DU distributed unit

[0037] eNB (or eNodeB) evolved Node B (e.g., an LTE base station)

[0038] EN-DC E-UTRA-NR dual connectivity

[0039] en-gNB or En-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DC

[0040] E-UTRA evolved universal terrestrial radio access, i.e., the LTE radio access technology

[0041] gNB (or gNodeB) base station for 5G/NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC

[0042] HARQ Hybrid Automatic Repeat reQuest

[0043] UF interface

[0044] IIoT Industrial Internet of Things

[0045] KPI Key Performance Indicator

[0046] LTE long term evolution

[0047] MAC medium access control

[0048] MME mobility management entity

[0049] ms millisecond

[0050] NACK Negative Acknowledgement

[0051] NDI New Data Indicator

[0052] ng or NG next generation

[0053] ng-eNB or NG-eNB next generation eNB

[0054] NR new radio

[0055] N/W or NW network

[0056] PDCCH Physical Downlink Control Channel

[0057] PDCP packet data convergence protocol

[0058] PDSCH Physical Downlink Shared Channel

[0059] PHICH Physical Hybrid ARQ Indicator Channel

[0060] PHY physical layer

[0061] PUSCH Physical Uplink Shared Channel [0062] RAN radio access network

[0063] Rel release

[0064] RLC radio link control

[0065] RNTI Radio Network Temporary Identifier

[0066] RRH remote radio head

[0067] RRC radio resource control

[0068] RU radio unit

[0069] Rx receiver

[0070] SDAP service data adaptation protocol

[0071] SGW serving gateway

[0072] SMF session management function

[0073] SR Scheduling Request

[0074] TS technical specification

[0075] Tx transmitter

[0076] UE user equipment (e.g., a wireless, typically mobile device)

[0077] UL uplink (from UE to RAN node)

[0078] UPF user plane function

[0079] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims.

[0080] The exemplary embodiments herein describe techniques for explicit NACK signaling performed in an optional manner suitable for 5G NR URLLC performance improvements. Additional description of these techniques is presented after a system into which the exemplary embodiments may be used is described.

[0081] Turning to FIG. 1, this figure shows a block diagram of one possible and non- limiting exemplary system in which the exemplary embodiments may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. In FIG. 1, a user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless, typically mobile device that can access a wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a control module 140, comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The control module 140 may be implemented in hardware as control module 140-1, such as being implemented as part of the one or more processors 120. The control module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 140 may be implemented as control module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[0082] The RAN node 170 is a base station (BS) that provides access by wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for instance, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (e.g., the network element(s) 190). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the FI interface connected with the gNB-DU. The FI interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the FI interface 198 connected with the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of an RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station.

[0083] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F(s)) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory/memories and processor(s), and/or other hardware, but these are not shown.

[0084] The RAN node 170 includes a control module 150, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The control module 150 may be implemented in hardware as control module 150-1, such as being implemented as part of the one or more processors 152. The control module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 150 may be implemented as control module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the control module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[0085] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more RAN nodes 170 communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., an Xn interface for 5G, an X2 interface for LTE, or other suitable interface for other standards.

[0086] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH/DU, and the one or more buses 157 could be implemented in part as, e.g., fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node 170 to the RRH/DU 195. Reference 198 also indicates those suitable network link(s).

[0087] The wireless network 100 may include a network element or elements 190 that may include core network functionality, and which provides connectivity via a link or links 181 with a further network, such as a telephone network and/or a data communications network (e.g., the Internet). Such core network functionality for 5G may include access and mobility management function(s) (AMF(s)) and/or user plane functions (UPF(s)) and/or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality. These are merely exemplary functions that may be supported by the network element(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to a network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an SI interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N W I/F(s)) 180, interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0088] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software -based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[0089] The computer readable memories 125, 155, and 171 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. The processors 120, 152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, and other functions as described herein.

[0090] In general, the various embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances (including Internet of Things devices) permitting wireless Internet access and possibly browsing, tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

[0091] It is noted that one possibility for the RAN 170 is a gNB. Below, the RAN 170 is referred to primarily as a gNB 170, although this is not a limitation and is for ease of reference only.

[0092] Having thus introduced one suitable but non- limiting technical context for the practice of the exemplary embodiments of this invention, the exemplary embodiments will now be described with greater specificity. [0093] As described above, the reliability for Rel-16 is to be increased even further over that for Rel-15. These very low latency, highly reliable enhancements require different uplink strategies.

[0094] One of the key, enabling features of URLLC in 3GPP Rel-15 is the notion of “Configured Grant” (CG), also known as grant-free operation for achieving low transmission latencies in the uplink direction for URLLC. See 3GPP, “Physical layer procedures for data”, 3GPP TS 38.214 V15.4.0 (2018-12) for information on grant-free operation. In this type of CG scenario, the phases of sending scheduling request and waiting for scheduling grant are skipped as shown in FIG. 2, which illustrates operation for uplink (UL) resource allocation by grant- free configuration and is used to compare operation with Configured Grant (CG) (bottom 250) and operation without CG (top 210). In CG, the UE is allocated (by the gNB) time-frequency resources (e.g., PRBs = physical resource blocks) periodically in time. Use of CG in bottom 250 allows the phases of scheduling request (SR) 220 by the UE and scheduling grant (UL DCI 235) by the gNB to be skipped and instead the UE can send uplink data on the very next configured grant scheduling opportunity.

[0095] In more detail, both the top 210 (without CG) and bottom 250 (with CG) start with data arrival 205 at a UE 110 and with corresponding UL processing 207, which is an amount of time needed for the UE 110 to process the data and respond via UL. In the top 210, the UE 110 has an alignment (align) phase 215, then sends a Scheduling Request (SR 220). The gNB 170 has an SR processing phase 225 phase, then has to wait for slot alignment 230. The gNB 170 performs an UL DCI 235, and then the UE 110 performs an uplink transmission (UL TX) 240 in another slot. By contrast, in the bottom 250, with CG, the UE 110 can perform the UL TX 250 without going through the SR 220 and the UL DCI 235. This is illustrated by the X 265 and the reduced UL scheduling handshake delay 260. This is because prior to data arrival 205, the gNB 170 has allocated time-frequency resources (e.g., PRBs = physical resource blocks) able to be used by the UE 110 periodically in time. The grant-free UL transmission as in the bottom 250 results in greater than or equal to two times (>= 2X) latency reduction, relative to the without CG operation in the top 210.

[0096] Such a mechanism reserves resources periodically in time and frequency that the UE can transmit on if the UE has data in its buffer, without waiting for a dynamic scheduling-grant on the PDCCH from the gNB 170. Note that on many occasions, these reserved resources may go unused, because when the UE has no data in its buffer to transmit, the UE 110 will not transmit anything such as padding bits or dummy information on its CG transmission opportunities as specified in the following: 3GPP, “Medium Access Control (MAC) protocol specification”, 3GPP TS 38.321 V15.4.0 (2018-12). This means the gNB’s receiver 162 needs to carry out what is known as “DTX detection”, as the gNB 170 does not know whether a UE transmitted on its CG resource. DTX stands for discontinuous transmission. So, the gNB 170 must first determine if the UE transmitted or not via a DTX detection stage, and if the gNB determines the UE transmitted something, then the gNB will try and decode the uplink transmission. If the gNB tried to just decode without first trying to detect if the UE transmitted anything, the gNB would be trying to decode essentially noise, resulting in a decoding error, and generating unnecessarily a retransmission request from the gNB to the UE, wasting air interface resources.

[0097] The current Rel-15 specification of Configured Grant utilizes what is known as an “implicit ACK” mechanism. What this means is that when a UE transmits data on a CG occasion, if the UE does not receive any request from the gNB to retransmit the packet via a PDCCH scheduling grant, then the UE assumes that its transmission was successful and does not attempt any type of autonomous retransmission. Note that in the Rel-15 specification, the gNB does not send an ACK or NACK in the downlink to inform the UE if its transmission on PUSCH was successful or not, such as in the PHICH channel that exists in LTE. Instead, the only way the UE knows if its PUSCH transmission failed is if the UE receives a PDCCH scheduling grant from the gNB requesting a retransmission. Hence the term “implicit ACK” is used, because if the UE does not hear anything from the gNB after the UE transmits, the UE implicitly assumes the gNB was able to successfully decode the data.

[0098] The problem of the existing implicit ACK mechanism is known, for instance being described in the Nokia RANI contribution in the following: 3GPP Tdoc Rl- 1900932 “On Configured Grant Enhancements for NR URLLC”, Nokia, January 2019. As an example, if the gNB fails to detect an actual uplink CG transmission by the UE using its DTX detection mechanism, then the gNB assumes the UE did not transmit on its CG resource and hence will do nothing. This is known as a missed detection event. From the UE’s point of view, because the UE does not receive any response from the gNB, the UE implicitly assumes ACK - meaning the UE implicitly assumes the transmission was successful and then moves on to transmit new data when the data arrives on future CG occasions. Hence, the data that was actually transmitted is lost at the MAC layer and can only be recovered using higher layer RLC layer retransmissions. Unfortunately, RLC retransmission incur significant latency well beyond the 1ms latency constraint of URLLC traffic, and hence this results in an immediate outage problem.

[0099] To illustrate these principles, reference is made to FIG. 3. This figure split into FIGS. 3(a), 3(b), and 3(c), illustrates the following: Current behavior on 3GPP Rel-15 specification of uplink configured grant when FIG. 3 (a) the gNB detects and decodes transmission successfully, FIG. 3(b) the gNB detects but does not decode transmission successfully, and FIG. 3(c) the gNB misses the detection of the UE transmission. Reference 300 indicates uplink configured grant (CG) time slots, and there are three of these: 300-1, 300-2, and 300-3. In each of FIGS. 3(a), 3(b), and 3(c), data arrives 320 and there is an initial UE data transmission 310 on the next CG timeslot.

[00100] In FIG. 3(a), the transmitted packet is detected and decodes successfully, so the gNB 170 does nothing. See reference 330.

[00101] In FIG. 3(b), in reference 340, the packet is detected by the gNB 170 but does not decode. In reference 350, the gNB 170 sends a PDCCH grant for retransmission. In response, in reference 360, the UE 110 retransmits the data on scheduled (non CG) resource(s).

[00102] In FIG. 3(c), as indicated by reference 370, the packet is not detected, and the gNB 70 does nothing. In reference 380, the UE discards the packet, as the UE thinks the gNB received the packet. The packet is, however, lost.

[00103] Because of the problem described above, several companies including Nokia proposed to introduce the notion of “explicit ACK” for Configured Grant. See 3GPP Tdoc Rl- 1900932 “On Configured Grant Enhancements for NR URLLC”, Nokia, January 2019. In this scenario, the UE behavior would change such that if the UE transmitted data on the uplink CG resource and if the UE did not explicitly receive an ACK from the gNB, then the UE will implicitly assume the gNB did not detect or decode the transmission. The UE will then autonomously retransmit the data on its configured grant resources. The benefit is that this latency-critical URLLC data is not lost in the case of missed detection by the gNB, as is the case with the existing “implicit ACK” mechanism such as illustrated in FIG. 3. To make the signaling efficient and compact, it was proposed in Rl- 1900932 to use the notion of group common ACK/NACK DCI similar to the existing DCI format 2_2 for group power control. This “explicit ACK” proposal essentially mandates that the gNB sends an ACK if the gNB detects and successfully decodes the UE’s configured grant transmission. This because the UE behavior is such that if the UE does not receive this explicit ACK from the gNB, the UE will autonomously retransmit on the next uplink configured grant resource, as illustrated in FIG. 4.

[00104] Turning to FIG. 4, this figure is split into FIGS. 4(a), 4(b), and 4(c), and illustrates the following: Behavior of “explicit ACK” proposal in Rl- 1900932 when FIG. 4(a) the gNB detects and decodes transmission successfully, FIG. 4(b) the gNB detects but does not decode transmission successfully, and FIG. 4(c) the gNB misses the detection of the UE transmission. This figure should be compared with FIG. 3.

[00105] In reference 405 of FIG. 4(a), the gNB detects the packet and decodes the packet successfully. In reference 410, the gNB sends an (explicit) ACK for this UE on group common DCI. This is different from FIG. 3(a), where nothing is sent by the gNB in response to the gNB’s detecting and decoding the packet successfully.

[00106] In FIG. 4(b), in reference 415, the gNB detects the packet but cannot decode the packet. The gNB does nothing, and the UE in reference 420 autonomously retransmits the previously transmitted data on the CG time slot 300-2. This is different from FIG. 3(b), where the gNB sends a PDCCH grant for retransmission in reference 350 and the UE retransmits data on a non-CG resource in reference 350.

[00107] In FIG. 4(c), the packet is not detected by the gNB and the gNB does nothing (reference 370). The UE autonomously retransmits data on CG time slot 300-2. See reference 430. This is in contrast to FIG. 3(c), where the UE discards the packet (see reference 380 in FIG. 3(c)), as the UE thinks the gNB received the packet, and the packet is lost.

[00108] The disadvantage of this technique is that it introduces considerable mandatory signaling overhead with the proposed behavior, as the gNB must now send an ACK for every uplink configured grant initial transmission.

[00109] This topic was debated in 3 GPP, and as discussed in the following, there was no consensus reached, with a number of companies concluding that the typical missed detection rate at the gNB is small enough in the scenarios of interest that the existing implicit ACK mechanism is sufficient and hence does not warrant introducing the high signaling overhead of the explicit ACK proposal. See NTT DOCOMO, INC., “Summary of 7.2.6.3 Enhanced configured grant PUSCH transmissions”, Rl-1903341, 3GPP TSG RAN WG1 Meeting #96, Athens, Greece, 25th February - 1st March 2019. On the other hand, also in Rl-1903341, there were arguments from several companies showing results in certain scenarios where the missed detection rate would be an issue and hence warrants the introduction of the explicit ACK mechanism. As no consensus was reached, this topic would not continue further in Rel-16 and may only be revisited in Rel-17.

[00110] Hence, a better method is needed which does not introduce this mandatory signaling overhead, but also addresses the need to solve the missed detection problem in scenarios or situations where this problem will impact the desired reliability level of the URLLC application.

[00111] To address these issues, what is proposed in exemplary embodiments herein is the notion of “explicit NACK” signaling from the gNB for uplink Configured Grant transmissions, but where the UE behavior is specified in such a way that this new signaling can be introduced in an optional and/or more selective manner so that no mandatory high signaling overhead method is introduced into the specifications.

[00112] In this way, the new “explicit NACK” signaling can be utilized only to those scenarios or applications in which the higher level of reliability of uplink configured grant transmissions is required and the signaling overhead is then justified to meet this requirement. Examples of applications with extremely high reliability requirements up to 99.9999% - 99.999999% are given in 3GPP, “Study for Communication for Automation in Vertical Domains”, 3GPP TR 22.804 V16.2.0 (2018-12). Exemplary details on how to introduce such an optional signaling are described in the next section regarding detailed implementation.

[00113] As discussed already, the problem with the “explicit ACK” proposal in 3GPP Tdoc Rl- 1900932 “On Configured Grant Enhancements for NR URLLC”, Nokia, January 2019 is that this proposal essentially mandates that the gNB sends an ACK if the gNB detects and successfully decodes the UE’s configured grant transmission. This was not agreed in 3GPP as this is significant additional signaling overhead that becomes a mandatory part of the specification. Arguments from other companies were that the increased level of reliability from “explicit ACK” is not needed in all circumstances, and that in many scenarios of interest the desired URLLC reliability level of say 99.999% or even 99.9999% can be met without “explicit ACK”. However other companies (including Nokia in Rl- 1900932) provided use cases where explicit ACK signaling from the gNB is needed to meet the desired URLLC reliability levels. These divergent views are shown in Rl-1903341.

[00114] It should also be pointed out that new use cases beyond the 99.999% - 99.9999% reliability levels studied as part of 3GPP Rel-15/Rel-16 may occur in the future for the new verticals described in 3 GPP, “Study for Communication for Automation in Vertical Domains”, 3GPP TR 22.804 V16.2.0 (2018-12)., where increased reliability levels of 99.99999% - 99.999999% may be needed. In this case, extra signaling that avoids the missed detection problem to achieve these increased reliability levels may be warranted, which is why this topic may be revisited in Rel-17, when there has been further experimentation with such reliability levels and use cases.

[00115] To order to avoid introducing mandatory extra signaling into the standard as done by the explicit ACK proposal in Rl- 1900932, but also have available a mechanism in the specification when we need increased reliability for uplink configured grant transmission (such as for the new verticals described in 3GPP, “Study for Communication for Automation in Vertical Domains”, 3GPP TR 22.804 V16.2.0 (2018-12)), we propose in the techniques herein to introduce the notion of “explicit NACK” signaling from the gNB for uplink Configured Grant transmissions, but specify the UE behavior in such a way that this new signaling can be introduced in an optional and/or more selective manner so that no mandatory high signaling overhead method is introduced into the specifications. In this way, the new “explicit NACK” signaling can be targeted only to those scenarios or applications in which the higher level of reliability of uplink configured grant transmissions is required and the signaling overhead then justified to meet this requirement.

[00116] First, an overview similar to FIGS. 3 and 4 is provided. Then, more details are provided.

[00117] Referring to FIG. 5, this figure split into FIGS. 5(a), 5(b), and 5(c), illustrates the following in an exemplary embodiment: Behavior of “explicit NACK” proposal in an exemplary embodiment when FIG. 5(a) the gNB detects and decodes transmission successfully, FIG. 5(b) the gNB detects but does not decode transmission successfully, and FIG. 5(c) the gNB misses the detection of the UE transmission.

[00118] In FIG. 5(a), there is an initial UE data transmission on the next CG time slot 300-1, in response to data arriving in reference 320. See reference 310. In reference 330, the gNB 170 detects and decodes the packet successfully, and the gNB does nothing. This is similar to FIG. 3(c), but the UE 110 in this case, as described in more detail below, is configured such that the baseline behavior is “implicit ACK”. This means if the UE does not receive a downlink PDCCH grant to retransmit its data packet, the UE will assume the initial configured grant transmission was successfully delivered. There is no ACK in FIG. 5(a), as there is in FIG. 4(a).

[00119] In FIG. 5(b), in reference 415, the packet is detected but does not decode. In response, the gNB 170 sends a NACK for this UE on group common DCI. An example of the group common DCI is described below. In reference 520, the UE 110 autonomously retransmits data on the CG time slot 300-2. Sending the NACK is different from both FIGS. 3(b) and 4(b).

[00120] In FIG. 5(c), the gNB 170 does not detect the packet in reference 505. In response, the gNB 170 sends (see reference 525) a NACK for this UE on the group common DCI. The UE in reference 530, in response, autonomously retransmits data on the CG time slot 300-2. Sending the NACK is different from both FIGS. 3(c) and 4(c).

[00121] Now that an overview has been provided, additional details are provided. These details are provided in reference to FIG. 6, which is split over FIGS. 6 A and 6B and is a signaling and logic flow diagram for explicit NACK signaling performed in an optional manner suitable for 5G NR URLLC performance improvements. FIG. 6 also illustrates the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiment. The operations in FIG. 6 for the UE 110 are assumed to be performed by UE under control at least in part by the control module 140, and the operations for the gNB 170 are assumed to be performed by gNB under control at least in part by the control module 150.

[00122] In signaling 605, the gNB 170 configures the UE 110 in a group of UEs with information for explicit NACK signaling. For instance, this could be configuration for group common DCI with a corresponding scrambling code and user location(s) within the group common DCI. This could be configured semi-statically, with a periodicity at least as often as the period of the Configured Grant period that is being used. Using group common DCI formats (such as format 2_2), up to 15 users can be in a single group. However, it is also possible to just have one user in a group. Additional exemplary details for group common DCI are provided below. It is also noted that although group common DCI is primarily considered herein, other ACK NACK signaling techniques may be used. This may also include a command to enable optional explicit NACK signaling, if the UE supports optional explicit NACK signaling. The gNB 170 in signaling 607 configures each UE in a group with allocated CG UL grants. That is, the UEs in the group will be provided with allocated CG UL grants, and it is assumed no UEs, one UE, some UEs, or all UEs in the group can transmit in any of the the allocated CG UL grants. The allocated CG UL grants comprise time-frequency resources. As previously described, these allocated time and frequency resources (e.g., via allocated PRBs) are allocated with a periodicity in time. The allocation may be semi-static, for instance. As is known, persistent scheduling enables radio resources to be semi- statically configured and allocated to a UE for a longer time period than one subframe, avoiding the need for specific downlink assignment messages or uplink grant messages for each subframe.

[00123] The baseline behavior (see block 610) is “implicit ACK”, meaning if the UE does not receive a downlink PDCCH grant to retransmit its data packet, the UE will assume the initial configured grant transmission was successfully delivered. Unlike the “explicit ACK” proposal in Rl- 1900932, if the gNB sends nothing, the UE will not autonomously retransmit anything, instead, the UE behaves as a Rel-15/16 UE. The UE 110 in signaling 615 performs initial data transmission on a next CG time slot 300 (e.g., 300-1 in FIG. 5), using the time-frequency resources that have already been assigned.

[00124] The concept of a group common DCI is introduced in certain exemplary embodiments. The group common DCI carries ACK/NACK signaling bits to a group of users configured with uplink configured grant together with a new group common RNTI (e.g., ACK-CG-RNTI) which scrambles the CRC on this new group common DCI. One exemplary possibility is to use the idea described in Rl-1900932 (see, e.g., Option 2 in “Explicit HARQ-Ack for autonomous retransmission” in Rl-1900932). As an example, there can be a 1 (one) bit indicator for each user in the group, so that the gNB may signal ACK=1 or NACK=0 for that bit. Note that the bit assignments are exemplary and can be reversed (i.e., ACK=0 or NACK=1).

[00125] As far as how the gNB 170 could utilize this new group common DCI carrying the configured grant ACK/NACK information, each time there is a time slot “T” where configured grants have been allocated, after attempting to receive the signals transmitted in the uplink at time slot “T”, the gNB would then respond by sending a group common DCI corresponding to those users which were allocated configured grant transmissions in time slot “T”. The following would then be performed by the gNB 170: [00126] (a) If a user signal was either not detected or detected but not decoded properly on the user’s CG resource in time slot “T”, a NACK would be signaled for this user in the group common DCI; or

[00127] (b) If a user signal was detected and decoded on its CG resource properly in time slot “T”, then the gNB can either do nothing (as the user is going to follow “implicit ACK” behavior by default), or if the gNB 170 is in any case sending the group common DCI to issue one or more NACKs to users that were not detected and/or not decoded in time slot “T”, the gNB 170 may signal an ACK for this use in the group common DCI.

[00128] As the system might be configured such that UEs are very frequently using all of their CG time slot allocations, and the initial transmissions succeed with a very high probability (i.e., 99.99% or greater on the first transmission), it may only rarely be the case where part (a) applies above and hence the explicit signaling of NACK may occur very infrequently, contributing low signaling overhead to the system.

[00129] References 620-640 of FIG. 6 provide examples illustrating these concepts. In block 620, the gNB 170 attempts to receive signals transmitted in UL in time slot “T” for UEs with allocated CG UL grants. This reception would be on the time-frequency resources already allocated by the gNB to the UE in reference 607. The gNB 170 in block 625 determines for which UEs there were signals received and decoded, and follows “implicit ACK” behavior and does nothing for these. That is, for any UEs transmitting data in uplink in an allocated CG time slot “T” (e.g., at some corresponding frequency resource(s)) and where the gNB 170 receives and decodes this data, the gNB 170 does nothing, as illustrated in FIG. 5(a). That is, no acknowledgement or other communication is transmitted from the gNB toward the UE. For all other UE(s) 110 (if there are any) transmitting data in uplink in an allocated CG time slot “T” and where the gNB 170 receives but does not decode this data or does not receive this data, the gNB 170 marks these as not acknowledged. For these UE(s), the gNB 170 then needs to send NACKs, such as illustrated in FIG. 5(b) (the gNB 170 receives but does not decode this data) or FIG. 5(c) (the gNB 170 does not receive the data).

[00130] Thus, in block 630, if there any NACKs, the gNB 170 configures a group common DCI, indicating ACK or NACK, corresponding to those users which were allocated configured grant transmissions in time slot “T”. If there are any NACKs, then the gNB 170 in signaling 640 sends the configured group common DCI to the UEs in the group. This means that even though there may only be one or a few UEs that sent data that was not received or decoded, in an exemplary embodiment, each the UEs in the group will have one or more indicators (e.g., bits) assigned to the UE. This is illustrated by group common DCI 631, which indicates one example of how a group common DCI (or part thereof) might be structured. In this example, the group common DCI 631 includes six bits, each indicating either an ACK (A) or a NACK (N).

[00131] Note that if there are no NACKs, then block 630 and signaling 640 would not be performed. In other words, if all UEs in the group have their UL data properly received and decoded by the gNB 170, then there is no need for the gNB 170 to perform block

630 and signaling 640. Thus, the explicit NACK signaling created by block 630 and signaling 640 are optional, as indicated by reference 641.

[00132] Configured Grant (CG) UEs in the group are asked to scan for this new group common DCI (e.g., transmitted on the Physical Downlink Control CHannel (PDCCH) in known resources) carrying ACK/NACK signaling bits scrambled with the scrambling code of, e.g., the ACK-CG-RNTI. See block 635. It is noted that for a given group common signaling, one needs to name the type of RNTI for the group, so here the same name is adopted as is used in Rl- 1900932, which was ACK-CG-RNTI. The CRC bits in the group common DCI are scrambled with whatever this group RNTI value (e.g., ACK-CG-RNTI) is called.

[00133] As indicated in block 640, if the UE 110 detects this new group common DCI 631, the UE 110 can check the ACK/NACK status for its last uplink configured grant transmission:

[00134] 1) If an ACK was signaled to this UE, the UE does nothing;

[00135] 2) If a NACK was detected but the UE had not transmitted anything on the last uplink configured grant resource, then the UE does nothing; or

[00136] 3) If a NACK was signaled to this UE and the UE had transmitted new data on the last uplink configured grant resource, then the UE should assume its last uplink configured grant transmission was not decoded or detected, and the UE autonomously retransmits the packet on the next CG time slot (e.g., 300-2 in FIGS. 5(b) and 5(c)). An example of one possible autonomous retransmission concept for configured grant is described in Rl- 1900932.

[00137] In block 645, if the UE 110 does not detect the new group common DCI

631 scrambled by, e.g., the ACK-CG-RNTI, the UE continues with the default behavior of “implicit ACK” as Rel-15 UEs currently behave. [00138] In the example of FIG. 6, in signaling 650, the UE 110 retransmits data (e.g., a packet) on the next (allocated) CG time slot, if necessary. For instance, if the UE received a NACK (N) in position 4 (the UE’ s user location) of the group common DCI 631 , the UE 110 would retransmit data on next CG time slot using signaling 650. Note that it is assumed only one bit is assigned to each UE, but it might be possible to have more than one bit assigned to a UE. Otherwise (e.g., the UE received an ACK (A) in another user location or locations of the group common DCI 631), the UE does not perform signaling 650. That is, both signaling 650 and the attempt to receive in block 655 are optional, as indicated by reference 651.

[00139] If any UEs were supposed to retransmit data, in block 655, the gNB 170 in block 655 attempts to receive, on next CG time slot, UL transmissions from UEs in the group that were previously sent NACKs. This reception would be on the time-frequency resources already allocated by the gNB to the UE in reference 607. Note that if all UEs were previously properly received and decoded, then this operation would not be performed.

[00140] As previously described, the system might be configured such that UEs are very frequently using all of their CG time slot allocations, and the initial transmissions succeed with a very high probability (i.e., 99.99% or greater on the first transmission), it may only rarely be the case where ACK/NACK information needs to be transmitted by the gNB 170, and hence the explicit signaling of NACK may occur very infrequently, contributing low signaling overhead to the system.

[00141] With the exemplary proposed behavior, the case of missed detection is handled, because if the UE transmitted but the gNB did not detect data, the gNB 170 will be sending a NACK on the new group common DCI carrying the ACK/NACK signaling, and the UE will retransmit.

[00142] It is also not required that this new group common DCI with ACK NACK be sent, because if the gNB sends nothing, it has been specified that if the UE does not detect this new group common DCI then the UE does nothing (i.e., does not attempt an autonomous retransmission), which is currently the default Rel-15 behavior.

[00143] The only thing that now becomes needed to avoid missed detection of data is for the gNB to send a NACK in response to the gNB 170 not detecting any transmission from the UE; this is why the techniques herein are referred to as “explicit NACK”. Again, one can see that if the system is in a scenario where an unacceptable missed detection rate is not expected, then the explicit NACK need not be signaled at all by the gNB ; this is what makes the proposed signaling as being referred to as “optional” (see reference 641 of FIG. 6 too).

[00144] It should be pointed out here that when a UE does not transmit on its CG resource, the gNB would not detect any signal with its DTX detection mechanism and now needs to signal explicitly a NACK in this proposal. This could be viewed as a disadvantage in that signaling is being sent by the gNB when there is in fact no data transmission by the UE and may not be suitable for the case where the traffic from the UE is expected to be very infrequent. However as described in 3GPP, “Study for Communication for Automation in Vertical Domains”, 3GPP TR 22.804 V16.2.0 (2018-12), there are many use cases where the traffic from the UE is not only frequent but also strictly periodic, in which case the CG resources in time could be aligned with the periodic transmission pattern from the UE and it is expected that the UE will be using the CG resources nearly 100% of the time.

[00145] What the proposed examples allow is that these examples leaves it up to the gNB implementation on whether to configure or use the new DCI format with, e.g., ACK-CG-RNTI to issue these group common configured grant ACK/NACK commands, because the UE behavior has been specified in such a way that it is no longer mandatory to send this ACK/NACK signaling (i.e. baseline Rel-15 UE behavior is set if the gNB does not choose to send this signaling). Hence this signaling can be used selectively in scenarios/deployments where ACK NACK signaling for uplink configured grants are needed to overcome unacceptable missed detection rates and achieve the target reliability KPI for the URLLC application or other applications requiring high reliability such as 99.99999% or higher reliability. Hence these methods now provide new tools that can be used selectively for the new verticals requiring extra high reliability levels

[00146] For example, if a URLLC IIoT network is being deployed for an indoor factory use case for a customer interested in an increased reliability level of less than lxlO ⁸ packet loss/excess delay (99.999999% reliability), the gNB implementation can then choose to make use of this new downlink group common ACK NACK signaling for configured grant to achieve this reliability level. Note other use cases for needing this ACK NACK signaling might be if the implementation is using overbooking of configured grant resources where collisions might occur, or if the particular channel environment is very harsh with very wide swings in received signal quality making detection of configured grant transmissions difficult. [00147] On the other hand, if the application requires a less stringent reliability level of say lxlO ⁵ or lxlO ⁶ error/excess delay (99.999% - 99.9999% reliability), there may be no need for this extra downlink signaling of ACK/NACK and hence air interface resources can be saved by not configuring or issuing these commands, and the UE behavior naturally follows Rel-15 (i.e., implicit ACK), and there is no autonomous UE retransmissions but instead the application can follow the Rel-15 behavior of issuing PDCCH grants for retransmissions.

[00148] Exemplary advantages and technical effects of the exemplary embodiments include the following. One exemplary advantage and technical effect over the existing “implicit ACK” specification in the standard is that the exemplary proposed methods provide solutions to the problem of unacceptably high missed detection rate relative to the desired URLLC reliability level.

[00149] Another exemplary advantage and technical effect over the “explicit ACK” technique is that this new “explicit NACK” method can be used by the gNB as an optional tool in the specification, meaning no mandatory additionally signaling is introduced, e.g., into a specification.

[00150] With regard to this exemplary advantage and technical effect over the “explicit ACK” technique, the “explicit NACK” can be used selectively on an as-needed basis to achieve the higher URLLC reliability targets to future proof the specification against new use cases that may arise (for example in the Industrial IoT setting in particular) for which more stringent reliability targets may be required, or if it is found in practice that even the 99.999% - 99.99999% reliability levels targeted for Rel-15 and Rel-16 are not achieved in a real deployed network, because the simulations in 3 GPP were not accurate enough or not aligned enough to real use cases to see the missed detection rate is indeed a bottleneck to achieving the desired reliability levels.

[00151] The following are additional examples.

[00152] Example 1. A method, comprising:

[00153] configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; [00154] determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots;

[00155] doing nothing by the base station for the user equipment of the group where there were signals received and decoded;

[00156] in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and

[00157] in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications.

[00158] Example 2. The method of example 1, wherein the reserved resources are for configured grant uplink grants.

[00159] Example 3. The method of any of examples 1 or 2, wherein sending a set of indications comprises sending the set of indications using a group common downlink control information that has been set up for the group by the base station.

[00160] Example 4. The method of example 3, wherein set of indications comprises a set of bits within part of the group common downlink control information, each of the user equipment in the group is assigned at least one bit from the set of bits, and each bit is used to indicate one of acknowledgement or negative acknowledgement.

[00161] Example 5. The method of example 4, wherein each of the user equipment in the group is assigned a single bit in the set of bits.

[00162] Example 6. The method of any of examples 3 to 5, further comprising configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

[00163] Example 7. The method of any of examples 3 to 6, further comprising scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

[00164] Example 8. The method of example 7, wherein the scrambling code comprises an ACK-CG-RNTI code. [00165] Example 9. The method of any of examples 1 to 8, wherein there is at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, and the method further comprises attempting to receive by the base station, in a time slot subsequent in time to the selected time slot, signals from the at least one user equipment.

[00166] Example 10. A method, comprising:

[00167] receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots;

[00168] scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots;

[00169] in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station;

[00170] in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following:

[00171] in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or

[00172] in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or

[00173] in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[00174] Example 11. The method of example 10, wherein the reserved resources are for configured grant uplink grants. [00175] Example 12. The method of any of examples 10 or 11, wherein the acknowledgement information comprises a set of indications, and scanning by the user equipment a resource location comprises scanning a group common downlink control information for the set of indications.

[00176] Example 13. The method of example 12, wherein:

[00177] the set of indications comprises a set of bits within part of the group common downlink control information;

[00178] scanning by the user equipment a resource location further comprises finding by the user equipment at least one bit from the set of bits, each bit used to indicate one of acknowledgement or negative acknowledgement; and

[00179] checking by the user equipment acknowledgment/negative acknowledgment status further comprises using acknowledgment/negative acknowledgment status for the at least one bit to determine whether the transmission by the user equipment in the selected time slot has or has not been acknowledged.

[00180] Example 14. The method of example 13, wherein the user equipment is assigned a single bit in the set of bits.

[00181] Example 15. The method of any of examples 12 to 14, further comprising configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

[00182] Example 16. The method of any of examples 12 to 15, further comprising scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

[00183] Example 17. The method of example 16, wherein the scrambling code comprises an ACK-CG-RNTI code.

[00184] Example 18. A computer program, comprising code for performing the methods of any of examples 1 to 17, when the computer program is ran on a computer.

[00185] Example 19. The computer program according to example 18, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with the computer.

[00186] Example 20. The computer program according to example 18, wherein the computer program is directly loadable into an internal memory of the computer. [00187] Example 21. An apparatus, comprising:

[00188] means for configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots;

[00189] means for determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots;

[00190] means for doing nothing by the base station for the user equipment of the group where there were signals received and decoded;

[00191] means, responsive to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, for sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and

[00192] means, responsive to all user equipment of the group having signals that were received and decoded, for not sending the set of indications.

[00193] Example 22. The apparatus of example 31, wherein the reserved resources are for configured grant uplink grants.

[00194] Example 23. The apparatus of any of examples 31 or 22, wherein the means for sending a set of indications comprises means for sending the set of indications using a group common downlink control information that has been set up for the group by the base station.

[00195] Example 24. The apparatus of example 23, wherein set of indications comprises a set of bits within part of the group common downlink control information, each of the user equipment in the group is assigned at least one bit from the set of bits, and each bit is used to indicate one of acknowledgement or negative acknowledgement.

[00196] Example 25. The apparatus of example 24, wherein each of the user equipment in the group is assigned a single bit in the set of bits.

[00197] Example 26. The apparatus of any of examples 23 to 25, further comprising means for configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

[00198] Example 27. The apparatus of any of examples 23 to 26, further comprising means for scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information·

[00199] Example 28. The apparatus of example 27, wherein the scrambling code comprises an ACK-CG-RNTI code.

[00200] Example 29. The apparatus of any of examples 31 to 28, wherein there is at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, and the apparatus further comprises means for attempting to receive by the base station, in a time slot subsequent in time to the selected time slot, signals from the at least one user equipment.

[00201] Example 30. A base station comprising the apparatus of any of examples 21 to 30.

[00202] Example 31. An apparatus, comprising:

[00203] means for receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots;

[00204] means for scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots;

[00205] means, responsive to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, for assuming an implicit acknowledgement has been performed by the base station;

[00206] means, responsive to detecting acknowledgement information, for checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and for performing by the user equipment one of the following:

[00207] in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or [00208] in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or

[00209] in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[00210] Example 32. The apparatus of example 31, wherein the reserved resources are for configured grant uplink grants.

[00211] Example 33. The apparatus of any of examples 31 or 32, wherein the acknowledgement information comprises a set of indications, and the means for scanning by the user equipment a resource location comprises means for scanning a group common downlink control information for the set of indications.

[00212] Example 34. The apparatus of example 33, wherein:

[00213] the set of indications comprises a set of bits within part of the group common downlink control information;

[00214] the means for scanning by the user equipment a resource location further comprises means for finding by the user equipment at least one bit from the set of bits, each bit used to indicate one of acknowledgement or negative acknowledgement; and

[00215] the means for checking by the user equipment acknowledgment/negative acknowledgment status further comprises means for using acknowledgment/negative acknowledgment status for the at least one bit to determine whether the transmission by the user equipment in the selected time slot has or has not been acknowledged.

[00216] Example 35. The apparatus of example 34, wherein the user equipment is assigned a single bit in the set of bits.

[00217] Example 36. The apparatus of any of examples 33 to 35, further comprising means for configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

[00218] Example 37. The apparatus of any of examples 33 to 36, further comprising means for scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information· [00219] Example 38. The apparatus of example 37, wherein the scrambling code comprises an ACK-CG-RNTI code.

[00220] Example 39. A user equipment comprising any of the apparatus of examples 31 to 38.

[00221] Example 40. A wireless communications system comprising any one of the apparatus of examples 21 to 30 and any one of the apparatus of examples 31 to 38.

[00222] Example 41. An apparatus, comprising:

[00223] one or more processors; and

[00224] one or more memories including computer program code,

[00225] wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising:

[00226] configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots;

[00227] determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots;

[00228] doing nothing by the base station for the user equipment of the group where there were signals received and decoded;

[00229] in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and

[00230] in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications.

[00231] Example 42. The apparatus of example 39, wherein the one or more memories and the computer program code are further configured, with the one or more processors, to cause the apparatus to perform the methods of any of examples 2 to 9.

[00232] Example 43. An apparatus, comprising: [00233] one or more processors; and

[00234] one or more memories including computer program code,

[00235] wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising:

[00236] receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots;

[00237] scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots;

[00238] in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station;

[00239] in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following:

[00240] in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or

[00241] in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or

[00242] in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

[00243] Example 44. The apparatus of example 43, wherein the one or more memories and the computer program code are further configured, with the one or more processors, to cause the apparatus to perform the methods of any of examples 11 to 17. [00244] As used in this application, the term “circuitry” may refer to one or more or all of the following:

[00245] (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

[00246] (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[00247] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.”

[00248] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[00249] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a “computer-readable medium” may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 1. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories 125, 155, 171 or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals.

[00250] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[00251] Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[00252] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

CLAIMS What is claimed is:

1. A method, comprising: configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; doing nothing by the base station for the user equipment of the group where there were signals received and decoded; in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications.

2. The method of claim 1, wherein the reserved resources are for configured grant uplink grants.

3. The method of any of claims 1 or 2, wherein sending a set of indications comprises sending the set of indications using a group common downlink control information that has been set up for the group by the base station.

4. The method of claim 3, wherein set of indications comprises a set of bits within part of the group common downlink control information, each of the user equipment in the group is assigned at least one bit from the set of bits, and each bit is used to indicate one of acknowledgement or negative acknowledgement.

5. The method of claim 4, wherein each of the user equipment in the group is assigned a single bit in the set of bits.

6. The method of any of claims 3 to 5, further comprising configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

7. The method of any of claims 3 to 6, further comprising scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

8. The method of claim 7, wherein the scrambling code comprises an ACK-CG-RNTI code.

9. The method of any of claims 1 to 8, wherein there is at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, and the method further comprises attempting to receive by the base station, in a time slot subsequent in time to the selected time slot, signals from the at least one user equipment.

10. A method, comprising: receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station; in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

11. The method of claim 10, wherein the reserved resources are for configured grant uplink grants.

12. The method of any of claims 10 or 11, wherein the acknowledgement information comprises a set of indications, and scanning by the user equipment a resource location comprises scanning a group common downlink control information for the set of indications.

13. The method of claim 12, wherein: the set of indications comprises a set of bits within part of the group common downlink control information; scanning by the user equipment a resource location further comprises finding by the user equipment at least one bit from the set of bits, each bit used to indicate one of acknowledgement or negative acknowledgement; and checking by the user equipment acknowledgment/negative acknowledgment status further comprises using acknowledgment/negative acknowledgment status for the at least one bit to determine whether the transmission by the user equipment in the selected time slot has or has not been acknowledged.

14. The method of claim 13, wherein the user equipment is assigned a single bit in the set of bits.

15. The method of any of claims 12 to 14, further comprising configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

16. The method of any of claims 12 to 15, further comprising scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

17. The method of claim 16, wherein the scrambling code comprises an ACK-CG-RNTI code.

18. A computer program, comprising code for performing the methods of any of claims 1 to 17, when the computer program is ran on a computer.

19. The computer program according to claim 18, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with the computer.

20. The computer program according to claim 18, wherein the computer program is directly loadable into an internal memory of the computer.

21. An apparatus, comprising: means for configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; means for determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; means for doing nothing by the base station for the user equipment of the group where there were signals received and decoded; means, responsive to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, for sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and means, responsive to all user equipment of the group having signals that were received and decoded, for not sending the set of indications.

22. The apparatus of claim 31, wherein the reserved resources are for configured grant uplink grants.

23. The apparatus of any of claims 31 or 22, wherein the means for sending a set of indications comprises means for sending the set of indications using a group common downlink control information that has been set up for the group by the base station.

24. The apparatus of claim 23, wherein set of indications comprises a set of bits within part of the group common downlink control information, each of the user equipment in the group is assigned at least one bit from the set of bits, and each bit is used to indicate one of acknowledgement or negative acknowledgement.

25. The apparatus of claim 24, wherein each of the user equipment in the group is assigned a single bit in the set of bits.

26. The apparatus of any of claims 23 to 25, further comprising means for configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

27. The apparatus of any of claims 23 to 26, further comprising means for scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

28. The apparatus of claim 27, wherein the scrambling code comprises an ACK-CG-RNTI code.

29. The apparatus of any of claims 31 to 28, wherein there is at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, and the apparatus further comprises means for attempting to receive by the base station, in a time slot subsequent in time to the selected time slot, signals from the at least one user equipment.

30. A base station comprising the apparatus of any of claims 21 to 30.

31. An apparatus, comprising: means for receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; means for scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; means, responsive to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, for assuming an implicit acknowledgement has been performed by the base station; means, responsive to detecting acknowledgement information, for checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and for performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

32. The apparatus of claim 31, wherein the reserved resources are for configured grant uplink grants.

33. The apparatus of any of claims 31 or 32, wherein the acknowledgement information comprises a set of indications, and the means for scanning by the user equipment a resource location comprises means for scanning a group common downlink control information for the set of indications.

34. The apparatus of claim 33, wherein: the set of indications comprises a set of bits within part of the group common downlink control information; the means for scanning by the user equipment a resource location further comprises means for finding by the user equipment at least one bit from the set of bits, each bit used to indicate one of acknowledgement or negative acknowledgement; and the means for checking by the user equipment acknowledgment/negative acknowledgment status further comprises means for using acknowledgment/negative acknowledgment status for the at least one bit to determine whether the transmission by the user equipment in the selected time slot has or has not been acknowledged.

35. The apparatus of claim 34, wherein the user equipment is assigned a single bit in the set of bits.

36. The apparatus of any of claims 33 to 35, further comprising means for configuring by the base station each of the user equipment in the group with information about the set of indications in the group common downlink control information and locations within the set of indications each of the user equipment should use.

37. The apparatus of any of claims 33 to 36, further comprising means for scrambling by the base station and using a scrambling code the set of indications in the group common downlink control information.

38. The apparatus of claim 37, wherein the scrambling code comprises an ACK-CG-RNTI code.

39. A user equipment comprising any of the apparatus of claims 31 to 38.

40. A wireless communications system comprising any one of the apparatus of claims 21 to 30 and any one of the apparatus of claims 31 to 38.

41. An apparatus, comprising: one or more processors; and one or more memories including computer program code, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising: configuring, by a base station in a wireless network, a group of one or more user equipment with reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment have data to transmit, in uplink in one of a plurality of time slots; determining, by the base station, for which user equipment of the group there were signals received and decoded, the signals received over the reserved resources in a selected one of the plurality of time slots; doing nothing by the base station for the user equipment of the group where there were signals received and decoded; in response to there being at least one user equipment of the group where signals from the at least one user equipment were not received or were received but not decoded, sending a set of indications including one or more indications of negative acknowledgment to the at least one user equipment and one or more indications of acknowledgment to all other user equipment in the group; and in response to all user equipment of the group having signals that were received and decoded, not sending the set of indications.

42. The apparatus of claim 39, wherein the one or more memories and the computer program code are further configured, with the one or more processors, to cause the apparatus to perform the methods of any of claims 2 to 9.

43. An apparatus, comprising: one or more processors; and one or more memories including computer program code, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising: receiving, at a user equipment in a wireless network and able to communicate with a base station in the wireless network, configuration comprising reserved resources that are reserved periodically in time and on which the user equipment can transmit, if the user equipment has data to transmit, in uplink toward the base station and in one of a plurality of time slots; scanning by the user equipment a resource location for acknowledgement information from the base station, the acknowledgement information for transmissions performed previous to the scanning in a selected one of the plurality of time slots; in response to there being no acknowledgement information detected and transmission of data by the user equipment in the selected time slot, assuming an implicit acknowledgement has been performed by the base station; in response to detecting acknowledgement information, checking by the user equipment acknowledgment/negative acknowledgment status in the acknowledgement information, and performing by the user equipment one of the following: in response to there being an acknowledgement of the data transmitted by the user equipment in the selected time slot, taking no action; or in response to there being a negative acknowledgement but the user equipment did not transmit data in the selected time slot, taking no action; or in response to there being a negative acknowledgement of the data transmitted by the user equipment in the selected time slot, assuming by the user equipment that its transmission of the data in the selected time slot was not decoded or detected by the base station, and autonomously retransmitting the data in a next time slot.

44. The apparatus of claim 43, wherein the one or more memories and the computer program code are further configured, with the one or more processors, to cause the apparatus to perform the methods of any of claims 11 to 17.