Patent Description:
3GPP R1-<NUM> describes that a dynamic TDD can lead to high BS-BS and UE-UE interference besides the conventional BS to UE and UE to BS interference. In NR, with heterogeneous deployment and various TTls (e.g., slot/mini-slot). To handle interference, schemes such as resource assignment, advanced receiver, and power/rate/precoding/beam control can be applied.

Under discussion are methods to enhance existing mobile communication systems to provide communication between a wide range of machines. A subgroup of this discussion relates to critical machine type communication (C-MTC) where the communication requirements of very low latency, very high reliability and very high availability must be fulfilled. Examples include:.

Candidate communication systems to fulfill such requirements are, e.g., LTE and a newly developed radio access called new radio (NR) by Third Generation Partnership Project (3GPP). In NR, a scheduling unit is defined either as a slot or a mini-slot. A NR slot consists of several Orthogonal Frequency Division Multiplexing (OFDM) symbols where one possible outcome is that it consists of seven OFDM symbols, but other structures such as fourteen OFDM symbols can be used as well. Also under discussion is that a NR slot may or may not contain both the transmission in the uplink (UL) and the downlink (DL), respectively. Therefore, three configurations of slots are being discussed, namely: (<NUM>) DL-only slot (<NUM>) UL-only slot (<NUM>) Mixed DL and UL slot.

<FIG> shows different cases with seven OFDM symbols. The case with fourteen OFDM symbols is similar, for example by doubling the case of seven OFDM symbols. In particular, Case (<NUM>) relates to a slot consisting of downlink only OFDM symbols, case (<NUM>) relates to a slot consisting of uplink only OFDM symbols, and case (<NUM>) relates to a slot consisting of downlink symbols followed by a guard time and uplink symbols.

Furthermore, in NR systems, different OFDM numerologies will be used which determine the duration of the OFDM symbols. Table <NUM> lists different OFDM numerologies with different OFDM symbol durations, cyclic prefix durations, and symbol lengths including cyclic prefix. Additional numerologies to those shown in Table <NUM> can be used as well.

To fulfill the requirements of latency critical applications (e.g., C-MTC use-cases as shown above), a mini-slot is also defined in NR. The starting position and length of the mini-slot is variable. The minimum possible length of a mini-slot is one OFDM symbol. However, the alignment of mini-slot and slot is relevant for better interworking and co-existence.

While still under discussion, the operation in NR-TDD is the most likely mode of operation for future systems in high frequency bands. Below are existing assumptions taken for NR-TDD operation:.

Some embodiments advantageously provide a method, system and network node configuring resources for control messages for optimizing Ultra-Reliable and Low-Latency Communications, URLLC, using new radio time division duplex, NR-TDD.

The dependent claims set out advantageous embodiments.

In NR-TDD the transmission opportunity delay has a large impact on latency. If downlink (DL) control is collected in one symbol in the beginning and the uplink (UL) control is collected in one symbol in the end, it is not possible to achieve a low round-trip time assuming realistic processing delay.

The disclosure is described within the context of NR, and advantageously distributes the control messages over a NR TDD slot to allow shortest possible round-trip time. In other words, at least two control messages are transmitted on different symbols in the same NR TDD slot, thereby providing at least two control channels in the NR TDD slot, where the at least two control channels could be at least two uplink channels or at least two downlink channels. This allows for the transmission latency to be minimized for both UL and DL data in NR TDD.

Before describing in detail exemplary embodiments that are in accordance with the disclosure, it is noted that the embodiments reside primarily in combinations of apparatus/node/wireless device components and processing steps related to configuring resources for control messages for optimizing Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD).

Accordingly, components have been represented where appropriate by conventional symbols in drawings, showing only those specific details that are pertinent to understanding the embodiments of the disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

As used herein, relational terms, such as "first," "second," "top" and "bottom," and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

The term "network node" or "radio network node" used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), nodes in distributed antenna system (DAS) etc..

The term wireless device used herein may refer to any type of wireless device communicating with a network node and/or with another wireless device in a cellular or mobile communication system. Examples of a wireless device are user equipment (UE), target device, device to device (D2D) wireless device, machine type wireless device or wireless device capable of machine to machine (M2M) communication, PDA, iPAD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles etc..

Note further that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices located at the same or different physical locations.

Referring now to the drawing figures in which like reference designators refer to like elements there is shown in <FIG> a block diagram of an exemplary system for configuring resources for control messages for optimizing Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD) in accordance with the principles of the disclosure and designated generally as "<NUM>. " System <NUM> includes one or more network nodes <NUM> and one or more wireless devices <NUM> in communication with each other via one or more communication links, paths and/or networks.

Network node <NUM> includes transmitter <NUM> and receiver <NUM> for communicating with wireless device <NUM>, other network nodes <NUM> and/or other entities in system <NUM> via one or more communication protocols such as LTE based communication protocols. In particular, the disclosure will be described herein within the context of NR-TDD. In one or more embodiments, transmitter <NUM> and/or receiver <NUM> may be replaced with one or more communication interfaces for communicating signals, packets, messages, etc..

Network node <NUM> includes processing circuitry <NUM> containing instructions which, when executed, configure processing circuitry <NUM> to perform network node <NUM> functions such as one or more functions described herein and with respect to <FIG>. In one or more embodiments, processing circuitry <NUM> includes memory <NUM> that is configured to store code such as configuration code <NUM>. For example, configuration code <NUM> includes instructions which, when executed by processor <NUM>, causes processor <NUM> to perform the configuration process discussed in detail with respect to <FIG>.

In addition to processor and memory, e.g., a traditional processor and memory, processing circuitry <NUM> may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry). Processing circuitry <NUM> may comprise and/or be connected to and/or be adapted for accessing (e.g., writing to and/or reading from) memory <NUM>, which may comprise any kind of volatile and/or non-volatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Such memory <NUM> may be adapted to store code executable by control circuitry and/or other data, e.g., data pertaining to communication, e.g., configuration and/or address data of nodes, modulation and coding schemes such as BPSK and QPSK, etc..

Processing circuitry <NUM> may be configured to control any of the methods described herein and/or to cause such methods to be performed, e.g., by network node <NUM>. Corresponding instructions may be stored in the memory <NUM>, which may be readable and/or readably connected to the processing circuitry <NUM>. In other words, processing circuitry <NUM> may include a controller, which may comprise a microprocessor and/or microcontroller and/or FPGA (Field-Programmable Gate Array) device and/or ASIC (Application Specific Integrated Circuit) device. It may be considered that processing circuitry <NUM> includes or may be connected or connectable to memory, which may be adapted to be accessible for reading and/or writing by the controller and/or processing circuitry <NUM>.

Wireless device <NUM> includes transmitter <NUM> and receiver <NUM> for communicating with network nodes <NUM>, other wireless devices <NUM> and/or other entities in system <NUM> via one or more communication protocols such as LTE based communication protocols. In one or more embodiments, transmitter <NUM> and/or receiver <NUM> may be replaced with one or more communication interfaces such as an air interface and/or other interface for communicating signals, packets, messages, etc..

Wireless device <NUM> includes processing circuitry <NUM> containing instructions which, when executed, configure processing circuitry <NUM> to perform wireless device <NUM> functions such as one or more functions described herein and with respect to <FIG> and <FIG>. In one or more embodiments, processing circuitry <NUM> includes memory <NUM> that is configured to store code such as operation code <NUM>. For example, operation code <NUM> includes instructions which, when executed by processor <NUM>, causes processor <NUM> to perform the configuration process discussed in detail with respect to <FIG>.

Processing circuitry <NUM> may be configured to control any of the methods described herein and/or to cause such methods to be performed, e.g., by wireless device <NUM>. Corresponding instructions may be stored in the memory <NUM>, which may be readable and/or readably connected to the processing circuitry <NUM>. In other words, processing circuitry <NUM> may include a controller, which may comprise a microprocessor and/or microcontroller and/or FPGA (Field-Programmable Gate Array) device and/or ASIC (Application Specific Integrated Circuit) device. It may be considered that processing circuitry <NUM> includes or may be connected or connectable to memory, which may be adapted to be accessible for reading and/or writing by the controller and/or processing circuitry <NUM>.

It is assumed that wireless device <NUM> and the network node <NUM> each require one OFDM symbol for the processing of a control message and the preparation of the transmission. This assumption is made for all numerologies described herein.

<FIG> is a flow diagram of an exemplary configuration process in accordance with the principles of the disclosure. In one or more embodiments, processing circuitry <NUM> is configured to configure positioning of at least two control messages over at least two symbols of a NR TDD slot (Block S100). For example, the two control messages are two control messages transmitted in uplink or two control messages transmitted in downlink. The configuring of positioning by the network node may be considered as any configuring of a transmission by the network node or any configuring of the wireless device which provides for downlink or uplink control messages or channels to be transmitted as described. In one or more embodiments, positioning of at least control messages over at least two symbols of a NR TDD slot includes network node <NUM> transmitting at least two control messages over at least two symbols of a NR TDD slot such as within at least two sPDCCHs of the NR TDD slot. For example, as illustrated in <FIG> (described below), network node <NUM> transmits at least two of the following downlink control messages: DL assignment, UL assignment and UL HARQ, to wireless device <NUM>. In one or more embodiments, positioning of at least control messages over at least two symbols of a NR TDD slot includes configuring or causing wireless device <NUM> to transmit at least two uplink control messages over at least two symbols of a NR TDD slot such as within at least two sPUCCHs of the NR TDD slot. For example, as illustrated in <FIG> (described below), wireless device <NUM> is configured or caused to transmit at least two of the following uplink control messages: DL HARQ and SR, to network node <NUM>.

For example, at least two control messages, e.g., first and second control messages, are positioned in at least two control channels such as, for example, the sPDCCHs or sPUCCHs, of a single slot (<NUM> or <NUM> symbols), where the at least two control channels could be at least two uplink channels or at least two downlink channels. In another example, different configurations are described herein with respect to <FIG>, in which the configuration of resources for at least two messages on at least two symbols in the NR TDD slot advantageously optimizes Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD). In one or more embodiments, the symbols are OFDM symbols that may be included in one or more control channels, i.e., control symbols. In one or more embodiments, the at least two symbols are different symbols in the time domain.

In one embodiment, processing circuitry <NUM> is configured to configure placement of downlink control messages over at least two symbols of a NR TDD slot. In one or more embodiments, a NR TDD slot includes at least two control channels such, for example, as two sPDCCHs or sPUCCHs, in the same NR TDD slot where the at least two control channels could be at least two uplink channels or at least two downlink channels. For example, different configurations are described herein with respect to <FIG>, in which the configuration of resources for at least two messages on at least two symbols in the NR TDD slot advantageously optimizes Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD). In one or more embodiments, the symbols are OFDM symbols that may be included in one or more control channels, i.e., control symbols.

<FIG> is a flow diagram of another embodiment of an operational process in accordance with the principles of the disclosure. In one or more embodiments, processing circuitry <NUM> is configured to operate according to a configured positioning of at least two control messages over at least two symbols of a NR TDD slot (Block S102). In one or more embodiments, operating according to a configured positioning of at least two control messages over at least two symbols of a NR TDD slot includes wireless device <NUM> receiving at least two control messages over at least two symbols of a NR TDD slot such as within at least two sPDCCHs of the NR TDD slot. For example, as illustrated in <FIG> (described below), wireless device <NUM> receives at least two of the following downlink control messages: DL assignment, UL assignment and UL HARQ, from network node <NUM>. In one or more embodiments, operate according to a configured positioning of at least two control messages over at least two symbols of a NR TDD slot includes wireless device <NUM> transmitting at least two control messages over at least two symbols of a NR TDD slot such as within at least two sPUCCHs of the NR TDD slot. For example, as illustrated in <FIG> (described below), wireless device <NUM> transmits at least two of the following uplink control messages: DL HARQ and SR to network node <NUM>. In other words, control messages refer to messages transmitted by network node <NUM> and/or wireless device <NUM>.

For example, different configurations are described herein with respect to <FIG> in which the configuration of resources for messages on at least two symbols significantly optimizes Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD). In one or more embodiments, the at least two symbols are different symbols in a time domain.

In this embodiment, processing circuitry <NUM> is configured to configure placement of uplink control messages over at least two symbols of a NR TDD slot. For example, different configurations are described herein with respect to <FIG>, in which the configuration of resources for messages on at least two symbols significantly optimizes Ultra-Reliable and Low-Latency Communications (URLLC) using new radio time division duplex (NR-TDD).

In one or more embodiments, the processes of <FIG> and <FIG> is combined such that the placement of both uplink (UL) control message and downlink (DL) control messages on respective symbols of a NR TDD slot is configured. As used herein, uplink refers to communications from wireless device <NUM> to network node <NUM>, while downlink refers to communications from network node <NUM> to wireless device <NUM>.

For example, <FIG> is a block diagram where the control messages in DL and UL are spread out across different symbols to allow for the shortest possible round-trip time for UL and DL. In particular, in one embodiment, a single slot such as a NR TDD slot includes two sPDCCHs or two sPUCCHs for carrying at least two control messages. The messaging, signaling, communication, etc., between network node <NUM> and wireless device <NUM> is illustrated in <FIG>. In one or more embodiments, for the control messages:.

In other words, network node <NUM> transmits control messages and receives certain data, control messages and/or signaling. The types of control messages transmitted and the type of data, control messages and/or signaling received varies based on the situation and/or examples such as those described with respect to <FIG>. Also, wireless device <NUM> receives control messages and transmits data based on the control messages and/or signaling such as DL HARQ and/or SR. The types of control messages received and the type of data and/or signaling transmitted varies based on the situation and/or examples such as those described with respect to <FIG>. In one or more embodiments, the uplink assignment is configured in a downlink symbol after the second downlink symbol of the NR TDD slot depending on the processing speed in network node <NUM> and/or the slot structure. In one or more embodiments, the downlink HARQ is configured in an uplink symbol earlier than the second to last uplink symbol of the NR TDD slot depending on the processing speed of network node <NUM> and/or slot configuration.

In some aspects, the transmission of the different control messages or channels is on different symbols (and/or different mini-slots) in a time domain, for the control channels in uplink and/or in downlink. For example, the uplink control messages are transmitted in separate symbols (and/or separate mini-slots) by a wireless device. For example, the wireless device is configured to transmit a first (e.g. DL HARQ) uplink control message in a separate, or different, symbol to a second (e.g. SR) uplink control message, in the time domain. The first and second control messages according to any example may be both uplink control messages or may be both downlink control messages. A slot may comprise either or both of uplink and downlink control messages.

In one or more embodiments, a minimum of two DL and two UL symbols in the slot such as a NR-TDD slot are used, and therefore allows a guard period of three symbols in the seven symbol slot case. In one or more embodiments, the UL assignment is transmitted in later symbols, and DL HARQ is transmitted in earlier symbols depending on the processing delay in network node <NUM> and wireless device <NUM>. This configuration is also relevant for the case of fourteen OFDM symbols per slot. In one or more embodiments, multiple OFDM symbols are used for the control messages as described herein.

In one or more embodiments, wireless device <NUM> and/or network node <NUM> automatically configure the placing of UL and DL control messages based on the slot configuration: number of DL symbols, number of guard symbols and number of UL symbols in a slot.

The location of the control messages such as the DL assignment on parts (in frequency) or the whole of the first OFDM symbol is preconfigured with a search space blindly detected by wireless device <NUM>. This control message indicates the location of DL data, and can also indicate the location of the UL assignment on parts (in frequency) of a later symbol/symbols. Optionally, the location of the UL assignment is also a preconfigured search space blindly detected by wireless device <NUM>.

In the presence of UL data in the slot for wireless device <NUM>, DL HARQ and SR can be punctured into the UL data transmission for this wireless device <NUM> on parts of the OFDM symbols.

If wireless device <NUM> has no UL data to transmit but DL HARQ and/or SR to transmit, a different channel can be used (similar to the physical uplink control channel ((PUCCH)). The DL HARQ message may however still have the same distribution in time: the placement may allow for processing in wireless device <NUM> and in network node <NUM>. The data symbol/symbols may therefore not come too soon, and should end before the last symbol to allow for processing. With three UL symbols a pattern of reference symbol-data symbol-reference symbol is therefore suitable, and with four symbols two data symbols can be surrounded by two reference symbols. The same structure can be used for SR if no DL HARQ is transmitted, alternatively, the last reference symbol is replaced with SR data whenever SR is to be indicated.

The following example demonstrates how transmission and retransmission is conducted for the DL and UL case using the control channel configuration described herein. In the examples of <FIG>, it is assumed that a one mini-slot has a length of one OFDM symbol, however other mini-slot lengths can be used in accordance with the teaching of the disclosure. A slot may have a length of <NUM> or <NUM> OFDM symbols. A mini-slot may have a length of less than the slot, e.g. <NUM>, <NUM> or <NUM> symbols, or <NUM> symbols for a <NUM> symbol slot. In TDD, uplink and downlink are transmissions are sequential in time, i.e. time division duplexed on the same frequency band. Before describing the configuration, symbol usage is described with respect to <FIG>. In particular, the symbol usage can vary as shown in <FIG>, options <NUM>-<NUM>, which have an impact on the overall latency for a transmission and retransmission. Three different options for the usage of symbols: (<NUM>) same ratio of DL and UL mini-slots protected by a guard-time, (<NUM>) higher ratio of UL symbols, and (<NUM>) higher ratio of DL only symbols, are illustrated. The options described with respect to <FIG> may also be considered as examples of the present disclosure. The choice of symbol configuration can be indicated during run-time in the first symbol, which in this embodiment is the first mini-slot, as an adaptation to traffic needs. Thus, the placement of UL and DL control can be configured based on the control message sent in the first symbol. In some aspects, the control messages (e.g. control messages transmitted in uplink from a wireless device) may be each be transmitted on one (or more) symbols in the time domain. In some aspects, the control messages transmitted in uplink may each be transmitted on a symbol, or, in a mini-slot, e.g. within a slot, a first control message is transmitted in an uplink mini-slot and a second control message is transmitted in a further, subsequent, uplink mini-slot. In some aspects, the control messages transmitted in downlink may each be transmitted in a symbol, or, in a mini-slot, e.g. within a slot, a first control message is transmitted in a downlink mini-slot and a second control message is transmitted in a further, subsequent, downlink mini-slot. A slot may comprise uplink control messages and/or downlink control messages. In some aspects, a control message may refer to a control channel, e.g. a first control channel comprising a first control message (e.g. DL HARQ) and a second control channel comprising a second control message (e.g. SR). As such, the different control channels, e.g. different types of control message (e.g., DL HARQ or SR) are transmitted on different symbols in a time domain within a slot. The remaining examples will be discussed based on option <NUM> illustrated in <FIG>. However, the approach described herein is similar for the remaining options of <FIG>.

<FIG> is a block diagram of the uplink transmission where after a scheduling request (SR) from wireless device <NUM> in symbol seven, first an uplink assignment (UA) in symbol two is sent in the DL. Subsequently, a data packet is sent using the last three symbols. The HARQ DL acknowledgement is sent for this data packet in symbol two. The uplink packet transmission using option <NUM> is successful. In other words, network node <NUM> transmits control messages and receives data and/or signaling. The types of control messages transmitted and the type of data received varies based on the situation and/or examples such as those described with respect to <FIG>. Also, wireless device <NUM> receives control messages and transmits data based on the control messages and/or transmits signaling. The types of control messages received and the type of data and/or signaling transmitted varies based on the situation and/or examples such as those described with respect to <FIG>.

<FIG> is a block diagram illustrating the situation where an uplink transmission fails and a retransmission takes place. In other words, network node <NUM> transmits control messages and receives data and/or signaling. The types of control messages transmitted and the type of data and/or signaling received varies based on the situation and/or examples such as those described with respect to <FIG>. Also, wireless device <NUM> receives control messages and transmits data based on the control messages and/ transmit signaling. The types of control messages received and the type of data and/or signaling transmitted varies based on the situation and/or examples such as those described with respect to <FIG>.

<FIG> is a block diagram illustrating the situation with a successful downlink transmission. In other words, network node <NUM> transmits control messages and receives data and/or signaling. The types of control messages transmitted and the type of data and/or signaling received varies based on the situation and/or examples such as those described with respect to <FIG>. Also, wireless device <NUM> receives control messages and transmits data based on the control messages and/or transmits signaling. The types of control messages received and the type of data and/or signaling transmitted varies based on the situation and/or examples such as those described with respect to <FIG>.

<FIG> is a block diagram illustrating the situation where a downlink data transmission fails and is transmitted afterwards. In other words, network node <NUM> transmits control messages and receives data and/or signaling. The types of control messages transmitted and the type of data and/or signaling received varies based on the situation and/or examples such as those described with respect to <FIG>. Also, wireless device <NUM> receives control messages and transmits data based on the control messages and/or transmits signaling. The types of control messages received and the type of data and/or signaling transmitted varies based on the situation and/or examples such as those described with respect to <FIG>.

<FIG> is a block diagram of an alternative embodiment of node <NUM> in accordance with the principles of the disclosure. Network node <NUM> includes configuration module <NUM> that performs the configuration process discussed in detail with respect to <FIG> and <FIG>, and the network node <NUM> signaling described in <FIG>. Therefore, the network distributes the control and feedback resources for wireless device <NUM> over the OFDM symbols in a slot so that the lowest possible latency can be realized in NR-TDD.

<FIG> is a flow diagram of an exemplary operational process of operation module <NUM> in accordance with the principles of the disclosure. Processing circuitry is configured to operate according to a configured positioning of at least two control messages over at least two symbols of a NR TDD slot in which the at least two symbols being different symbols in a time domain (Block S104). In one or more embodiments, processing circuitry <NUM> is configured to receive control messages in which the control messages are placed in at least two symbols of a new radio time division duplex (NR-TDD) slot. In one or more embodiments, processing circuitry <NUM> is configured to transmit information. For example, in one or more embodiments, the information is transmitted based on the received control messages. In one or more embodiments, processing circuitry <NUM> performs blind detection of an indication of the configuration of the placement of control messages, i.e., performs blind detection of an indication of the configuration of the placement of control messages as described above with respect to the "Physical Resources" section such as the "DL control", "UL control with data" and "UL control without data" sections. For example, based on the control messages, wireless device <NUM> is able to transmit signal(s), message(s) and/or information as described with respect to <FIG>, and/or knows to expect signal(s), message(s) and/or information as described with respect to <FIG>.

<FIG> is a block diagram of an alternative embodiment of wireless device <NUM> in accordance with the principles of the disclosure. Wireless device <NUM> incudes operation module <NUM> that performs the configuration process discussed in detail with respect <FIG>, and perform wireless device <NUM> messaging described in <FIG>.

Claim 1:
A network node (<NUM>) using new radio time division duplex, NR TDD, the network node (<NUM>) comprising:
processing circuitry (<NUM>) configured to:
configure positioning of at least two control messages over at least two symbols of a NR TDD slot, wherein the NR TDD slot comprises a minimum of two downlink and two uplink symbols in the NR TDD slot, and
wherein the at least two control messages are different types of control message, and
wherein the at least two control messages on the at least two symbols are on different uplink symbols in a time domain;
wherein each control message corresponds to a respective symbol of the at least two symbols of the NR TDD slot;
wherein the at least two control messages include:
a downlink Hybrid Automatic Repeat Request, HARQ, configured to be positioned on a first symbol of the at least two symbols of the NR TDD slot; and
a scheduling request configured to be positioned on a second symbol of the at least two symbols of the NR TDD slot, the first symbol being positioned, in the time domain, before the second symbol.