NZ752145B2 - Node for a radio communication network and operating method - Google Patents

Abstract

Methods and systems for a 3GPP radio communication network for selecting a relative timing from among a plurality of predetermined relative timing choices for sending a second transmission from a wireless device in response to receiving a first transmission from a network node. Whereby the network node being arranged for sending of the first transmission and subsequent receiving of the second transmission in response to said first transmission, wherein said network node is furthermore arranged to perform a selecting process for selecting a relative timing for sending of said second transmission from among a plurality of predetermined relative timing choices, and to send to the wireless device Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set. The wireless device being arranged for reception of the first transmission and subsequent sending of the second transmission in response to said first transmission, wherein said wireless device is furthermore arranged to receive from the network node Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises the RRC control message for configuring the set of possible relative timing selections and the DCI control message for selecting from the configured set, and to perform a selecting process for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, wherein the selecting said relative timing for sending said second transmission is done according to the received DCI control message. ode being arranged for sending of the first transmission and subsequent receiving of the second transmission in response to said first transmission, wherein said network node is furthermore arranged to perform a selecting process for selecting a relative timing for sending of said second transmission from among a plurality of predetermined relative timing choices, and to send to the wireless device Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set. The wireless device being arranged for reception of the first transmission and subsequent sending of the second transmission in response to said first transmission, wherein said wireless device is furthermore arranged to receive from the network node Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises the RRC control message for configuring the set of possible relative timing selections and the DCI control message for selecting from the configured set, and to perform a selecting process for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, wherein the selecting said relative timing for sending said second transmission is done according to the received DCI control message.

Description

[Title] Node for a radio communication network and operating method [Technical Field] The present invention relates to radio communication networks generally, in which transmissions are sent between nodes, and especially to a node for such a communication network and a method of operating such a node.

[Background] Radio communication ks which are currently deployed and/or being ped include networks having a UMTS (Universal Mobile Telecommunications ; also known as 3G) or an LTE (Long Term Evolution; also known as 4G) architecture. Presently, a further standard ed to as New Radio (NR), but also known as 5G or Next Generation, is under development.

In such networks, network nodes (e.g. denoted eNodeB or eNB in LTE, and gNB in NR) and wireless devices (e.g. user equipments, UEs) send and receive radio transmissions, some of which are sent in response to preceding transmissions.

In LTE architectures, the relative timing of such response is fixed by the agreed standards.

For example, ACK/NACK feedback is used by a node receiving a transmission to inform a transmitting node that its transmission has been or has not been successfully received. The ACK/NACKs may be transmitted in response to downlink (DL) transmissions by UE (via UL control channel or data channel) or eNB (via Physical Hybrid Indicator Channel PHICH) in response to uplink (UL) issions, respectively.

Depending on the configuration of the network, a HARQ feedback transmitted by the wireless device is in l transmitted 4 subframes after (n+4) the reception of a transmission (in me n), for frequency division duplex (FDD). For Time division duplex, TDD, the relation is also fined. In Half Duplex FDD, HD-FDD, the timing relation between reception of data at the UE and transmission of HARQ A/N in the uplink is also predefined e.g. in Narrowband Internet of Things, NB-IoT, the CK is sent in subframe n+12.

NR architectures being currently discussed by the Third Generation Partnership Project, 3GPP, are ged to offer some level of interoperability with LTE networks.

[Summary] The object of the invention is to provide a node for a radio communication network with more flexibility with respect to a ication mechanism sing the reception of a first transmission and the subsequent sending of a second transmission in se to the first transmission. ing to an embodiment, a wireless device for a 3GPP radio ication network is proposed. The wireless device is arranged for ion of a first transmission and subsequent sending of a second transmission in response to said first ission, wherein said wireless device is furthermore arranged to receive from a network node Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for uring a set of possible relative timing selections and a DCI control message for selecting from the configured set, and to m a selecting process for selecting a relative timing for sending said second transmission from among a ity of predetermined relative timing choices, wherein the selecting said relative timing for sending said second transmission is done according to the received DCI control message.

In ance with this concept, the node, which in the context of the bed communication mechanism may be the sending node of the first transmission or the sending node of the second transmission, is not limited to necessarily setting the timing for the sending of the second transmission in a predetermined way like in the prior art, but is e of performing a selecting process for selecting a relative timing. The expression “relative timing” means that there is a plurality (i.e. two or more) of choices that are different with respect to one another in terms of their relative timing, i.e. if there are n relative timing choices Ci, where i=1, …, n, then the choices Ci relate to a temporal hierarchy for the sending of the second transmission from fastest to slowest in the sense that the sending of the second transmission for choice Ci will be earlier than the sending of the second transmission for choice Ci+1. Naturally, the entation of the choices can also be in the inverse, i.e. the choices Ci may equally be presented as a temporal hierarchy from slowest to fastest in the sense that the g of the second transmission for choice Ci will be later than the g of the second transmission for choice Ci+1. As an example, the concept may be embodied as a first choice C1 = “fast” and a second choice C2 = “slow”, such that if choice C1 is selected the sending of the second transmission will be earlier than if choice C2 is selected.

As can be seen, the choices Ci only relate to a relative timing with respect to one another, so that there is no limitation to associated actual time . rmore, the actual time at which the second ission is sent for each choice Ci may vary from one instance of sending the second transmission to another instance of sending the second transmission, as long as the hierarchy of relative timings between different choices is maintained.

Nonetheless, if desired, the concept can be embodied as a set of actual time values (e.g. difference times ∆Ti expressing a time difference between ing the first transmission and sending the second transmission) associated with each choice Ci. However, the concept can equally well be embodied as a set of transmission mechanisms Mi, each of which is associated with a relative , thereby again providing a hierarchy of timing choices, e.g. from fastest to slowest or vice-versa, or ordered some other way.

Due to the described concept, a node of a radio communication network becomes more flexible, as the response time for reacting to the first transmission by sending the second ission can be variably controlled.

According to a further embodiment, a network node for a 3GPP radio ication network is proposed. The network node is arranged for sending of a first ission and subsequent receiving of a second transmission in response to said first transmission, wherein said network node is furthermore arranged to m a ing process for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, and to send to a wireless device Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control e signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set.

According to a further embodiment, a method of operating a wireless device for a 3GPP radio communication network, comprises: receiving, from a network node, Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling ses an RRC control message for configuring a set of possible relative timing ions and a DCI control message for selecting from the configured set, receiving a first transmission; selecting a relative timing for sending a second transmission in response to said first transmission, the relative timing being selected from among the ured set, and wherein the ing said ve timing for sending said second ission is done according to the received DCI control message; and g a second ission in accordance with the selected relative timing.

According to a further embodiment, a method of operating a network node for a 3GPP radio communication network , comprises: sending a first ission to a wireless device; and receiving a second transmission in response to said first transmission, wherein said method also comprises selecting a relative timing for sending said second transmission in response to said first transmission, the relative timing being selected from among a ity of predetermined relative timing choices, and further comprising: sending to said wireless device Radio ce Control, RRC, and nk Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set.

[Description of Figures] The following description of embodiments and preferred examples, which are to be understood as illustrative but not as limiting, will make reference to Figures, in which: Fig. 1 shows a schematic representation of an example of a communication k; Fig. 2 shows a schematic representation of a node according to the presently described concept; Fig. 3 shows a flow chart of a method embodiment; Fig. 4 shows a flow chart of another method embodiment; Fig. 5 shows a flow chart of another method embodiment; Fig. 6 shows a flow chart of r method embodiment; Fig. 7 shows a flow chart of another method embodiment; Fig. 8 shows a schematic e of NR architecture; Fig. 9 shows NR deployment examples; Fig. 10 shows e subcarrier spacing candidate configurations for NR; Fig. 11 shows an example of a DL-heavy slot with CK feedback at the end; Fig. 12 shows an e of two different relative timings for sending a second ission with feedback in response to having received a first transmission; Fig. 13 shows a first scenario of resource allocation and data transmission in response; Fig. 14 shows a second scenario of resource allocation and data transmission in response; Fig. 15 shows a third io of ce allocation and data transmission in response; Fig. 16 shows an example of how DL HARQ feedback is transmitted at the end of a DL-heavy slot duration as a form of “immediate” ACK/NACK; and Fig. 17 shows an example of a feedback transmission delayed with respect to the “Immediate” ck of the example of Fig. 16.

[Detailed description of embodiments] Fig. 1 shows a schematic representation of a radio communication network 1, which is shown as having one or more core parts (or core networks) 10 and one or more access parts (or access networks) 11. The core part 10 is arranged to provide core control and management functions, while the access part 11 is arranged to let end nodes 12 access the radio communication network 1. The concept of core and access parts or networks is well known, such that a further description is not necessary. Fig. 1 furthermore shows core network nodes 101 and access network nodes 111. The presently described concept is applicable to any of the described nodes, i.e. can be embodied in an end node 12, an access node 111 and/or a network control node 101 of the core part 10. The concept is also not limited to any particular communication technology, such that it can be applied e.g. to 3G, 4G and/or 5G, and to any mixed architecture of different technologies.

An example of an end node is a user equipment (UE) or any other device arranged for accessing the network 1 via the access part 11. As such, an end node can be a radio device, a mobile phone, a mobile er, a relay, but also any appropriately equipped sensor, actuator or other element designed for onnectivity, e.g. IoT elements (IoT = Internet of Things). It should also be noted that although the end nodes are arranged to communicate through the network 1 both among each other and with nodes in other networks than network 1, e.g. with computer servers located e.g. in the Internet, end nodes may also be arranged for direct communication with one another. The end node herein can thus be any type of wireless device capable of communicating with an access node or another end node over radio signals. The end node may also be radio ication device, target device, device to device (D2D) UE, machine type UE or UE capable of e to machine communication (M2M), a sensor equipped with UE, tablet, mobile terminal, smart phone, laptop ed equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE) etc.

The access node can be any kind of network node which may comprise a radio network node such as base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), network controller, gNodeB, gNB, NR BS, evolved Node B (eNB), Node B, Multi-cell/multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU), Remote Radio Head (RRH), a multi-standard BS (MSR BS).

The network control node can be any core network node, e.g. MME ity Management Entity), SON (Self-Organizing Network) node, a coordinating node, positioning node, MDT (Minimization of Drive Tests) node, etc., or even an external node (e.g., 3rd party node, a node external to the current network 1), etc.

In the present description, the term “network node” is used for both access nodes and network control nodes. A network node may also se a test ent.

Fig. 2 shows a schematic representation of a node for a radio communication network according to the present concept. The node 20 comprises an interface part 201 for ication with other nodes. If the node 20 is an end node, e.g. end node 12 of Figure 1, then the interface part 201 will be arranged for radio communication. If the node 20 is an access node, e.g. access node 111 of Figure 1, the interface part will be arranged for radio communication with end nodes and for one or both of wire-bound and radio communication with network control nodes of the core network. If the node 20 is a network control node of the core network, e.g. network control node 101 of Figure 1, the interface part will be arranged for one or both of wire-bound and radio communication with access nodes. The interface part 201 may furthermore be arranged to perform measurements relating to communicating conditions of the node, e.g. signal th. However, node 20 may also have dedicated measuring ent (not shown) or test equipment (not shown).

The node 20 furthermore ses a control part 202 for controlling the operation of node , especially the communications and/or measurements performed by the ace part 201, but also the processing of data and information received. The control part can be provided in any suitable or desirable way, e.g. comprising one or more programmable processors and one or more memory and storage devices for storing control software and s data.

In accordance with the present concept, node 20 is arranged for a communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission. An example of such a mechanism is where the first transmission comprises data and the second transmission comprises feedback information related to a receipt of that data. Various such feedback isms are known, e.g. ARQ atic Repeat reQuest) mechanisms or HARQ (Hybrid-ARQ) isms. Such ARQ or HARQ mechanisms may involve the sending of ACK/NACK (Acknowledgment/Negative Acknowledgement) messages ng to the reception state of the data received in the first ission, such that in exemplary cases of the present concept, the second ission may comprise ACK/NACK information.

Other examples of feedback information that can be sent in the second transmission are CSI (Channel State Information) feedback or CQI (Channel Quality Indicators) feedback.

Another example of a communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first ission is when the first ission comprises resource allocation information and the second transmission comprises data, said data being sent over a resource allocated with the resource allocation ation. In exemplary cases of the present concept, the first transmission may e.g. comprise scheduling information.

In the context of the presently described concept, the node 20 may be involved in ent ways in the described communication mechanism. For example, the node 20 may be the receiver of the first transmission and the sender of the second transmission. If the node 20 is an end node, then the first transmission may comprise a DL (down link) data communication and the second transmission may comprise an UL (uplink) feedback message relating to the ion status of the DL data ication. Equally, the first transmission may be ling information sent on the DL and the second ission may be an UL transmission in response to the received scheduling information. If the node 20 is an access node, then the first transmission may comprise an UL data communication and the second transmission may comprise a DL feedback message relating to the reception status of the UL data communication.

However, the node 20 may also be sender of the first transmission and the er of the second transmission. Or the node 20 may also be a network node sending control information to one or both of other nodes acting as sender and receiver of the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to the first transmission.

Besides being applicable to UL or DL communication, the presently described concept is e.g. also applicable to sidelink communication or to communication between (or among) two or more end nodes, between (or among) two or more access nodes or between (or among) two or more network control nodes.

Furthermore, the presently described concept can be employed in connection with any d type of carrier or channel for the first and second transmission, e.g. one or both can be carried over a l channel (e.g. a Physical Uplink Control Channel, PUCCH or Physical Downlink Control Channel, PDCCH) or a data channel (e.g. a Physical Downlink Shared Channel, PDSCH or al Uplink Shared Data Channel, .

In accordance with the present t, the control part 202 of node 20 may comprise an arrangement 2021 for performing a selecting process for selecting a relative timing for sending the second transmission from among a plurality of predetermined relative timing choices. The arrangement 2021 may be ed in any suitable or ble way, e.g. as hardware, software or any suitable ation of hardware and re. For example, the arrangement 2021 may be a computer program part designed to be executed on a sor of the node 20.

The expression “relative timing” means that there is a plurality (i.e. two or more) of choices that are different with respect to one another in terms of their relative timing, i.e. if there are n relative timing choices Ci, where i=1, …, n, then the choices Ci relate to a temporal hierarchy for the sending of the second transmission from fastest to slowest in the sense that the sending of the second transmission for choice Ci will be earlier than the sending of the second transmission for choice Ci+1. lly, the representation of the choices can also be in the inverse, i.e. the choices Ci may equally be presented as a al hierarchy from slowest to fastest in the sense that the sending of the second transmission for choice Ci will be later than the sending of the second transmission for choice Ci+1. As an example, the concept may be embodied as a first choice C1 = “fast” and a second choice C2 = “slow”, such that if choice C1 is selected the sending of the second transmission will be earlier than if choice C2 is ed. As another example, the concept may be embodied as a first choice C1 = “fast”, a second choice C2 = “medium”, and a third choice C3 = “slow”, such that if choice C1 is selected the sending of the second transmission will be earlier than if choice C2 is selected, and if choice C2 is selected the sending of the second transmission will be earlier than if choice C3 is selected.

As can be seen, the choices Ci only relate to a relative timing with respect to one another, so that there is no limitation to ated actual time values. rmore, the actual time at which the second transmission is sent for each choice Ci may vary may vary from one instance of sending the second transmission to another ce of sending the second transmission, as long as the hierarchy of relative timings between different choices is maintained. Nonetheless, if desired, the concept can be embodied as a set of actual time values (e.g. difference times ∆Ti expressing a time difference between receiving the first transmission and sending the second ission) associated with each choice Ci. However, the concept can equally well be embodied as a set of transmission mechanisms Mi, each of which is associated with a relative timing, thereby again providing a hierarchy of timing choices from fastest to slowest or vice-versa.

Fig. 3 shows a flow chart of a basic method embodiment of the presently described concept.

Within the method 3 for operating a node of a radio communication network, e.g. node 20 of Fig. 2, the node being adapted for a communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to the first transmission, there is ed a selecting process S31 for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices.

An example of a further method embodiment is shown in the flow chart of Fig. 4. Within the method 4 for operating a node of a radio communication network, e.g. node 20 of Fig. 2, the node being adapted for a communication mechanism comprising the ion of a first transmission and the uent sending of a second ission in response to the first transmission, there is provided a step S41 of receiving the first ission, a selecting process S42 for ing a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, and a step S43 of sending the second transmission in accordance with the selected relative timing.

The methods of Fig. 3 or 4 may additionally comprise a step uent to selection process S31 or S42 that ses sending a control message indicating the selected relative timing for sending said second transmission to another node. An example is shown in Fig. 5, where step S51 comprises sending such a control message. Although step S51 is also subsequent to step S43 in this example, this is not necessary, as step S51 could also be prior to step S43 or in parallel thereto. The other node may be the direct communication partner in the transmission mechanism, i.e. the node that sent the first transmission, or it could be some other node, like a control node in the network 1. The control message may also be sent to a plurality of nodes. By virtue of the control message, the other node, e.g. the intended receiver of the second transmission, is made aware of the timing choice of the node sending the second transmission and can thus appropriately control its ion process. However, it is to be noted that it is not necessary that a control message be sent, as e.g. the node intended to receive the second transmission can be equipped to perform the same selecting process like S31 or S42, i.e. apply the same logic or algorithm and the same input information as the node executing method 3 or method 4, thereby deriving the same relative timing choice without receiving a control message.

The sending of the control message may be automatically done after each tion of the selecting process, but may also be triggered differently, e.g. upon request of another node or in dependence on an outside event.

The methods of Fig. 3, Fig. 4 or Fig. 5 may also comprise a step prior to selection process S31 or S42 that comprises receiving a control message (e.g. a DCI message, where DCI stands for nk Control Information) indicating the ed relative timing for sending said second transmission from another node. The l e could also be an RRC (Radio Resource Control Message). An example is shown in Fig. 6, where step S61 comprises receiving such a control message. Although step S61 is subsequent to step S41 in this example, this is not necessary, as step S61 could also be prior to step S41 or in el thereto. The selecting process S31 or S42 for selecting the relative timing for g the second ission can then take into account the ed control message. The taking into account can be such that the control message is a command message and the selecting process then follows received command. The taking into account can, however, also be such that the control message is an information message informing the node of a suggestion of another node for the relative timing choice, where the selecting process S31 or S42 may or may not follow the suggestion, i.e. has the freedom to make a different choice. In the latter case it is preferable that the method 3, 4, 5, or 6 comprise a control message sending step like step S51 of Fig. 5, in order to indicate the selected relative timing choice to the one or more other nodes, e.g. as a command message or as an information message.

As already mentioned the control message may be one or both of a DCI message and an RRC message. Preferably a combination of RRC and DCI l message signalling is used. For example an RRC control message may configure a le set of values (for example taking into account the other node’s capabilities), and the DCI control message may select one of the configured s. More detailed examples of this are given in the following. The DCI message could select (e.g. via 1 or 2 bits) one out of 2 or 4 values for a se time configured by an RRC e. The values that RRC can ure could e.g. depend on numerology, ally the smallest possible value to configure. Response time could be the time between (end of) DL data ission and PUCCH (HARQ feedback) transmission.

Another e is the time between end-of-UL-grant and the start of UL transmission. Note furthermore that a given rier spacing is an example of a numerology, and a given m response time, e.g. expressed as a number of symbols, is an example of a capability.

Examples: Example A: For 15 kHz subcarrier spacing, UE needs at least 1 OFDM symbol n end of DL data and start of PUCCH.

Example B: For 30 kHz subcarrier spacing, UE needs at least 2 OFDM symbols between end of DL data and start of PUCCH.

Example C: For 60 kHz subcarrier spacing and more, UE needs at least 4 OFDM symbols between end of DL data and start of PUCCH.

A configuration, e.g. via RRC, may se defining a set of possible relative timing selections in terms of a number of OFDM s, i.e. a first timing selection is expressed as n1 OFDM symbols, a second timing selection is expressed as n2 OFDM symbols, etc., where ni are s. If the selection control signalling (e.g. via DCI) is 1 bit, then the set of possible selections has two member {n1, n2}, if the selection control signalling (e.g. via DCI) is 2 bits, then the set of possible ions may have two to four members {n1, n2, n3, n4}, etc. The smallest number among the ni must be at least as large as the minimum response time indicated above, i.e. 1 for Example A, 2 for Example B, and 4 for Example C. Naturally, the smallest number may be larger than the minimum spacing. In this way a “slower” response time adjustment is possible. To give examples, in the case of a 1-bit selection signalling, a configuration for Example A could be {1, 2}, for Example B {2, 3} and for Example C {4, 5}. A different, “slower” configuration could be {3, 6} for Example A, {5, 8} for Example B and {7, 10} for Example C.

Note that for a given numerology, e.g. a 15 kHz subcarrier spacing, there can be ent nodes (e.g. terminals) having different capabilities, e.g. one node having a minimum response time of 1 OFDM symbol and another node having a minimum response time of 3 OFDM symbols. The possible configurations then take these different capabilities into account accordingly, i.e. as explained above, the smallest number among the ni must be at least as large as the minimum response time.

Example D: For 15 kHz subcarrier spacing, UE needs at least 2 OFDM symbols between end of UL grant and start of UL transmission. e E: For 30 kHz subcarrier spacing, UE needs at least 3 OFDM symbols between end of UL grant and start of UL transmission.

Example F: For 60 kHz subcarrier spacing and more, UE needs at least 4 OFDM symbols between end of UL grant and start of UL transmission.

Similar to the explanation for Examples A-C, in the case of a 1-bit selection signalling, a configuration for Example D could be {2, 3}, for Example E {3, 4} and for Example F {4, 5}. A different, “slower” configuration could be {4, 6} for Example D, {6, 8} for Example E and {8, } for Example F.

Note that although these examples use the number of OFDM symbols as the expression of a time delay, this is only one possibility among many and other representations are possible, e.g. using absolute time expressed in microseconds or seconds.

A further example of a method embodiment is shown in the flow chart of Fig. 7. Within the method 7 for operating a node of a radio communication network, e.g. node 20 of Fig. 2, the node being adapted for a communication ism comprising the ion of a first ission and the subsequent sending of a second transmission in se to the first transmission, there is provided a step S71 of sending the first ission, a ing process S72 for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, and a step S73 of receiving the second transmission. The node executing method 7 may control the reception process for ing the second transmission in accordance with the selected relative timing choice.

The methods of Fig. 3 and 7 may additionally comprise a step subsequent to process S31 or S71 of g a l message indicating the selected relative timing of process S31 or S72 to one or more other nodes, especially the node to which the first transmission is sent.

The control message may be in the form of a command message instructing the other node(s) to select the same relative timing choice, or in the form of an information message comprising the selection made by process S31 or S72 as a suggestion for the relative timing choice to be made in the other node(s).

The s of Fig. 3 and 7 may furthermore onally comprise a step prior to process S31 or S72 of receiving from another node a control message indicating a selected relative timing choice, especially from the node to which the first transmission is sent. The control message may be in the form of a command message instructing the node running method 7 to select the same relative timing choice in process S31 or S72, or in the form of an ation message sing a suggestion for the relative timing choice to be made in the process S31 or S72.

The operating methods of Figures 3 – 7 will generally comprise further conventionally known steps and processes belonging to the ion of a communication node, as indicated by the dotted lines in the figures, but these are not described r, as they are not pertinent to the presently described concept.

A node according to the presently described concept, e.g. node 20 as shown Fig. 2, may furthermore be arranged to send information associated with the node’s capability of supporting one or more of said plurality of ermined relative timing choices to one or more other nodes. For e, the information associated with the node’s capability of supporting one or more of the plurality of predetermined relative timing choices may comprise information on one or more numerologies supported by the node. Accordingly, the methods of Figures 3 to 7 may comprise anywhere within said methods a step of sending information associated with the node’s capability of supporting one or more of said plurality of predetermined relative timing s to another node, preferably prior to the selecting process S31, S42 or S72, and more preferably prior to engaging in the communication mechanism comprising the reception of a first ission and the subsequent g of a second transmission in response to said first transmission, i.e. prior to the steps S41 or S71.

A node according to the presently described concept, e.g. node 20 as shown Fig. 2, may additionally or alternatively be arranged to receive from r node information associated with the other node’s capability of supporting one or more of said plurality of predetermined relative timing choices. Accordingly, the methods of s 3 to 7 may comprise anywhere within said methods a step of receiving from another node information associated with the other node’s capability of supporting one or more of the plurality of predetermined ve timing choices, preferably prior to the selecting process S31, S42 or S72, and more preferably prior to engaging in the communication ism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission, i.e. prior to the steps S41 or S71. This capability information may then be used for ing relative timing choices in subsequent instances of ming process S31, S42 or S72, i.e. the selecting process takes into account the received information associated with the other node’s capability of supporting one or more of said plurality of predetermined relative timing choices, when selecting said relative timing for sending said second transmission.

The criteria or dependencies that the selecting arrangement 2021 or the selecting process S31, S42 or S72 employ for selecting a relative timing choice may be chosen in any suitable or ble way. According to a preferred ment, the selecting process is arranged to take into account information associated with one or more communicating ions of one or both of the nodes involved in the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission, i.e. the node receiving the first ission and sending the second transmission and/or the node sending the first transmission and receiving the second ission. The taking into account of the information associated with one or more communicating conditions may be direct in the sense that the node having the selecting arrangement or performing the selecting process directly processes the ation associated with one or more communicating conditions in the selection procedure, or may be indirect in the sense that a control e (such as the control message S61 described above in connection with Fig. 6) indicating the ed relative timing was generated in a s directly taking into account the information associated with the one or more communicating conditions, but the node having the selecting arrangement or ming the selecting process only receives the l message and then simply follows a command for timing selection comprised in the control message. The taking into t of the information associated with one or more communicating conditions of one or both of the nodes involved in the communication mechanism can also be combined with the previously mentioned taking into account of the other node’s capabilities of supporting one or more of the plurality of predetermined relative timing choices.

The communication conditions may relate to one or both of the transport of the first transmission (e.g. the signal or carrier carrying the first transmission and/or the channel carrying the first transmission and/or the bearer carrying the first transmission) and the transport of the second transmission (e.g. the signal or carrier carrying the second transmission and/or the l carrying the second transmission and/or the bearer carrying the second transmission).

The communicating conditions may comprise a set of one or more physical layer gs provided for said communication mechanism. An example of such a set is a logy.

Examples of a logy are one or more of subcarrier spacing, cyclic prefix, l spacing, number of RBs (radio bearers) within a given bandwidth, symbol length, subframe length, slot length, etc. The selecting process could thus take into account one or both of the used logy or numerologies and the capability of the other node to support a timing choice given the used numerology or numerologies.

The communicating conditions may furthermore comprise a carrier frequency.

The communicating conditions may furthermore comprise any suitable communication quality indicator, such as the coverage level. The communication quality may be assessed in any suitable or desirable way. For example, in the communication between an end node and an access node, an indicator (e.g. the ge level) can be determined by ing one or more radio ement values associated with the communication quality, where these values may be compared to a set of thresholds, each threshold corresponding to a given coverage level. The term “radio measurement” may refer to any measurement med on radio signals. Radio measurements can be absolute or relative. Radio measurements can be e.g. intra-frequency, inter-frequency, CA, etc. Radio measurements can be unidirectional (e.g., DL or UL) or bidirectional (e.g., RTT, Rx-Tx, etc.). Some examples of radio measurements: timing measurements (e.g., TOA (Time of Arrival), timing advance, RTT (Round Trip Time), RSTD (Reference Signal Time Difference), SSTD (Synchronization Signal Time Difference), Rx-Tx time difference, propagation delay, etc.), angle measurements (e.g., angle of arrival), power-based measurements (e.g., received signal power, RSRP (Reference Symbol Received Power), received signal quality, RSRQ (Reference Symbol ed y), SINR, SNR, path loss, interference power, total interference plus noise, RSSI, noise power, etc.), cell detection or identification, beam detection or identification, system information reading (e.g. acquisition of MIB and/or one or more SIBs etc), acquisition of cell global ID (CGI), RLM, channel availability (e.g., when the channel is accessed based on a CSMA-like or ke scheme), load tion or load measurement, channel occupancy measurement, CSI etc. Examples of CSI measurements are CQI, PMI, RI, CRI etc.

The communicating conditions may furthermore comprise one or both of the distance and the speed difference between the two nodes involved in the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission.

The radio communication network may be a cellular k, and the communicating conditions may comprise a cell range of a cell in which one or both of the nodes involved in the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission are located.

The communicating conditions may furthermore se a temporal characteristic associated with the communication between the two nodes involved in the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission. As such, the information associated with one or more communicating conditions may comprise one or more of a time of arrival, a timing advance, a round-trip delay time, a reference signal time difference, a synchronization signal time ence, an Rx-Tx time difference, and a propagation delay.

In accordance with the presently described concept, the selection process may take into account one or more measurement results. A measurement may be, e.g., one or more radio measurements. In another example, a measurement may be the evaluation of a statistical e (e.g., probability of an error/failure/successful operation). A measurement result may comprise a result of one or more measurements, i.e. the processing of different measurement values into processed values also generates a measurement .

In association with the relative timing choice, there may be a timing on related to the time difference or response time ∆T n the ion of the first transmission and the sending of the second ission. The timing relation may be expressed in any le and desirable way in terms of a given number of time resources, e.g. as physical time (measured e.g. in seconds), as a number of (one or more) ns of a , as a number of (one or more) symbols, as a number of (one or more) time slots, as a number of (one or more) mes, as a number of (one or more) slots, as a number of (one or more) radio , as a number of (one or more) TTIs, as a number of (one or more) interleaving times, etc.

In accordance with the presently described concept, the selected relative timing choice may be applied in the same way to a group of different types of communications each falling under a respective communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission. For example, a first type of communication may relate to a sending HARQ feedback in response to receiving a data transmission, a second type of communication may relate to sending a CSI feedback in response to receiving a data or reference signal transmission, and a third type communication may relate to sending data in response to receiving a resource allocation. For example, the same timing relation between the reception of a first signal at the radio node and the transmission of a second signal by the radio node may be d for all types of responses grouped together e.g. same for HARQ, CSI, UL data transmission etc..

The definition of such a group may be done in any suitable or desirable way, e.g. cover all types of communications fulfilling the definition of a communication ism sing the reception of a first transmission and the subsequent sending of a second ission in se to said first transmission. However, it also possible to define a smaller group for common application of the relative timing choice, e.g. the timing on between the reception of a first signal at the node and the transmission of a second signal by the node may be the same for at least the types of response signals which are transmitted concurrently e.g. same for HARQ and CSI if they are transmitted at the same time or in the same channel/radio resources.

However, in accordance with the presently described concept, the selection of a relative timing choice may also be different for different types of communications g under a respective communication mechanism sing the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission. In other words, in the context of the above example of a first type of communication relating to a sending HARQ feedback in response to receiving a data transmission, a second type of communication relating to sending a CSI feedback in response to receiving a data or reference signal transmission, and a third type communication relating to sending data in response to receiving a resource allocation, an individual relative timing choice (and possibly corresponding individual timing relation) may be made for each individual type of communication.

Now further examples of applying the presently described concept will be described.

Receiving node examples In a node involved in the communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission and acting as the ing node of the first transmission red to as “receiving node” in the following), methods of the following kind may be d.

• Step 0 nal): Indicating to another node the receiving node’s lity related to the support of flexible response transmission times and/or mechanisms • Step 1: Determining a time of receiving or expecting one or more radio signals/channels for which a response (e.g. ck) needs to be transmitted • Step 2: Selecting one from a plurality of the relative timing choices, e.g. associated with corresponding response transmission times or mechanisms, depending on one or more communication conditions, e.g. one or more of: numerology, carrier frequency, cell range, measurement, and threshold or condition o Step 2a (optional): ting to another node the ed choice • Step 3: Sending at least one feedback to another radio node, based on the selected choice.

Different possibilities for steps 0 -3 will be described in the following.

Step 0 In this step, the receiving node may indicate to another node (e.g., UE, radio network node, core network node) the receiving node’s capability related to the support of le response transmission time and/or mechanism.

In a further ment, the capability may further comprise or be indicative of the response transmission time or mechanism options ted by the receiving node.

The lity may be provided upon a request from the other node or in an unsolicited way, e.g., upon a triggering condition, event, receiving a triggering message from another node, etc.

Step 1 In this step, the receiving node may determine a time of receiving or expecting one or more radio signals/channels for which a response is to be itted. For example, a signal/channel is received in a time resource#K (e.g. subframe/slot#N and/or symbol#M).

The determining may be, e.g., based on the actual reception time, scheduling information, pre-defined rule, etc.

Step 2 In this step, the receiving node may select one from a plurality of relative timing s, e.g. feedback transmission times or mechanisms, directly or indirectly depending on one or more of: numerology, carrier frequency, coverage level, cell range, measurement, and threshold or condition. Any of the above parameters and/or the selection method may be obtained based on, e.g., • Measurement, • Pre-defined rule • Statistics • e or configuration from another node One example of plurality of relative timing choices ses: - Short delay (aka faster response) e.g. response sent in time resource K + 1, - Long delay (aka slower se) e.g. response sent in time resource K + 4.

Another example of plurality of response transmission time comprises: - Short delay (aka faster response) e.g. response sent in time ce K + 1, - Intermediate delay (aka moderate response) e.g. response sent in time resource K + 3, - Long delay (aka slower response) e.g. response sent in time resource K + 6.

One example of ity of feedback transmission mechanisms Mi ses e.g. any two or more of: - Fast ACK/NACK feedback channel which is transmitted at the end of a DL-heavy slot (same slot or slot in near future), - Alternative feedback is another feedback mechanism that is itted over a longer transmission duration in an UL slot, - -like feedback (e.g., vely long feedback) In a further embodiment, the receiving node may also indicate to another node (e.g., the node which is going to receive the response or to another UE, radio network node, or core network node) the selected choice, e.g. ck transmission time and/or mechanism. The indication may be, e.g., upon a request or upon triggering condition or event.

For example, one or any combination may apply: • First choice, e.g. first response transmission time and/or mechanism may be selected for a numerology comprised in a first set of numerologies, second choice, e.g. response transmission time and/or mechanism may be selected for a numerology sed in a second set of numerologies, e.g.: o A faster response (mechanism) may be selected for a subcarrier g of the ion and/or feedback below a first threshold o A slower response (mechanism) may be selected for a subcarrier spacing of the reception and/or response above a second threshold Note that depending on entation also the te can occur, i.e. a faster response (mechanism) may be selected for a subcarrier spacing of the reception and/or feedback above a first threshold and a slower response (mechanism) may be selected for a subcarrier spacing of the reception and/or se below a second threshold.

• First choice, e.g. first response transmission time and/or mechanism may be selected for a carrier frequency comprised in a first set of carrier frequencies, second choice, e.g. second se transmission time and/or mechanism may be selected for a carrier frequency comprised in a second set of carrier frequencies, e.g.: o A faster response (mechanism) may be transmitted on a carrier frequency of the reception and/or response below a first threshold o A slower response (mechanism) may be itted on a carrier frequency of the reception and/or response above a second threshold • First choice, e.g. first response transmission time and/or mechanism may be selected for a cell range comprised in a first set of cell , second choice, e.g. second response transmission time and/or ism may be selected for a cell range comprised in a second set of cell ranges, e.g.: o Where the first set of cell ranges comprises cell ranges below a threshold, and the second set of cell ranges comprises cell ranges above a threshold • First choice, e.g. first response transmission time and/or mechanism may be selected for a first measurement result, second , e.g. second response transmission time and/or mechanism may be selected for a second measurement result, e.g., o The first measurement result is received signal strength or quality is above a threshold and/or a timing measurement value is below a threshold, the second measurement result is received signal strength or quality is below a threshold and/or a timing measurement value is above a threshold. o The first measurement result is channel availability is above a threshold, the second measurement result is channel availability is below a threshold o The first measurement result is load is above a threshold, the second measurement result is load is below a threshold • More specifically in one example the receiving node may select the first choice, e.g. first response transmission time and/or ism if the path loss with respect to other radio node is below path loss threshold and the propagation delay n the radio node and the other radio node is also below propagation delay threshold, otherwise the radio node may select the second choice, e.g. second response transmission time and/or ism. The path loss threshold and propagation delay threshold may be pre-defined or configured at the radio node by controlling node.

The controlling node may also be the other radio node to which the se is sent by the receiving node.

• In yet another example if the receiving node cannot reliably perform one or more radio ements used for selecting the choice, e.g. response transmission time and/or mechanism then the ing node may select a reference , e.g. reference response transmission time and/or mechanism or a pre-defined one. The measurement may be considered able if the cy is worse than a threshold e.g. if pathloss measurement accuracy is worse than ±6 dB. In one example the reference response time can be the longest of the possible response times. In another example the reference response time can be an intermediate value out of the possible response times. In yet another example the reference response time can be configured at the receiving node by another node.

In the above examples the first response ission time and the second response transmission time may correspond to shorter response delay and longer response delay respectively.

Step 3 In this step, the receiving node may send at least one response to r radio node, based on the selected choice, e.g. response transmission time and/or mechanism.

The sending may further comprise sending a response via a physical channel (e.g., UL control channel). g node examples In a node involved in the communication ism comprising the reception of a first transmission and the subsequent sending of a second transmission in response to said first transmission and acting as the sending node of the first transmission (referred to as “sending node” in the ing), methods of the following kind may be applied.

• Step 0 (optional): Receiving from a receiving node an indication of its capability related to the support of flexible response ission times and/or mechanisms • Step 1: Selecting one from a plurality of the relative timing choices, e.g. feedback transmission times and/or mechanisms for the receiving node, depending on one or more of: logy, carrier frequency, coverage level, cell range, measurement, and threshold or condition • Step 2 (optional): Controlling the receiving node’s selection of the relative timing choice, e.g. associated with a feedback transmission time and/or mechanism, based on the selection result • Step 3 (optional): Adapting resource scheduling or at least one parameter related to the response transmission and/or for the radio signals/channels for which the response is to be sent, based on the selection result • Step 4: Receiving one or more ses from the receiving node, based on the selection result Different possibilities for steps 0 -4 will be described in the following.

Step 0 In this step, the sending node may receive from a receiving node an tion of its capability related to the support of flexible feedback transmission times and/or mechanisms.

See also Step 0 in the us ption of receiving node embodiments.

The received capability information may further be used in the next steps, e.g., to ensure that the selected relative timing choice e.g. feedback transmission time and/or mechanism is ted by the receiving node.

Step 1 In this step, the sending node may select one from a plurality of the relative timing choices, e.g. ck transmission times and/or mechanisms for the receiving node, depending on one or more of: numerology, carrier frequency, coverage level, cell range, measurement, and threshold or condition.

The selection s, principles and rules may be similar to those described for the receiving node.

In addition, the ion may be based on the measurement results received from the receiving node and/or measurement results obtained at the sending node (e.g., based on radio transmissions by the receiving node).

Step 2 In this step, the sending node may control the ing node’s selection of the relative timing choice e.g. feedback transmission time and/or mechanism, based on the selection result. This can be done by any suitable or desirable type of control message, e.g. via DCI (Downlink Control Information). Equally, the control message could be an RRC (Radio Resource Control) message, e.g. semi-statically configured. RRC and DCI signaling can be used in combination, e.g. an RRC l message configures a possible set of values (for example taking into t the other node’s capabilities), and the DCI control message selects one of the configured options.

The controlling may se, e.g., sending to the receiving node one or more ters based on the selection result to enable the receiving node to select or determine the relative timing choice, e.g. response transmission time and/or mechanism based on the result of the selection in the sending node.

Step 3 In this step, the sending node may adapt resource scheduling or at least one parameter related to the response transmission and/or for the radio signals/channels for which the response is to be sent, based on the selection .

For e, a faster ling may be used if a faster response (e.g. feedback or UL transmission) is selected. Another example is that a DL transmission may stop early in a slot (see Figure 11), to enable transmission on feedback at the end of the slot duration.

Step 4 In this step, the sending node may receive one or more responses from the receiving node, based on the selection result.

The presently described concept can be ed in the context of any communication mechanism comprising the reception of a first transmission and the subsequent sending of a second transmission in se to said first ission. According to a preferred embodiment, the concept is applied in the context of the introduction of the NR or 5G ecture, aspects of which will be described in the following.

NR (a.k.a. 5G or Next Generation or New Radio) architecture is being sed in 3GPP and the current concept is illustrated in Figure 8, where eNB denotes LTE eNodeB, gNB denotes NR Base Station (NR BS) (one NR BS may correspond to one or more transmission/reception points), and the lines between the nodes illustrate the corresponding interfaces which are under discussion in 3GPP. Further, Figure 9 illustrates deployment scenarios with NR BS which are discussed in 3GPP.

The NR radio frame structure is being discussed for NR. However, it has been agreed already that multiple numerologies, multiplexed in time and/or frequency will be supported in NR.

Furthermore, the radio frame may consist of a ent number of smaller time units, e.g., symbols.

For LTE, the term “numerology” includes, e.g., the following elements: frame duration, subframe or TTI duration, slot duration, subcarrier spacing, cyclic prefix length, number of subcarriers per RB, number of RBs within the bandwidth rent numerologies may result in different numbers of RBs within the same bandwidth).

The exact values for the numerology elements in different radio access technologies are typically driven by performance targets, e.g., performance requirements impose constraints on usable subcarrier g sizes, e.g., the maximum acceptable phase noise sets the minimum subcarrier bandwidth while the slow decay of the spectrum (impacting filtering complexity and and sizes) favors smaller subcarrier bandwidth for a given carrier frequency, and the ed cyclic prefix sets the maximum subcarrier bandwidth for a given carrier frequency to keep overhead low.

However, the numerology used so far in the existing RATs is rather static and lly can be trivially derived by the UE, e.g., by one-to-one mapping to RAT, frequency band, service type (e.g., MBMS), etc.

In LTE downlink which is OFDM-based, the rier g is 15 kHz for normal CP and 15 kHz and 7.5 kHz (i.e., the reduced carrier spacing) for extended CP, where the latter is allowed only for MBMS-dedicated carriers.

The support of multiple numerologies has been agreed for NR, which can be multiplexed in the frequency and/or time domain for the same or ent UEs.

In NR, which is to be based on OFDM, multiple numerologies will be supported for general operation. A g approach (based on a scaling factor 2^n, ��∈ℕ4) is considered for deriving subcarrier spacing candidates for NR. Values for subcarrier bandwidths currently discussed include among others 3.75 kHz, 15kHz, 30 kHz, 60 kHz. The numerology-specific slot durations can then be determined in ms based on the rier spacing: subcarrier spacing of (2m*15)kHz gives exactly 1/2m X ms for a slot that is X ms in the 15 kHz numerology, where X may e.g. be 0.5 or 1 .

Subcarrier spacings of at least up to 480 kHz are currently being discussed for NR (the highest discussed values correspond to millimeter-wave based technologies). It was also agreed that multiplexing different numerologies within a same NR carrier bandwidth is supported, and FDM and/or TDM multiplexing can be considered. It was further agreed that multiple frequency/time portions using different numerologies share a synchronization signal, where the synchronization signal refers to the signal itself and the time-frequency ce used to transmit the synchronization signal. Yet another ent is that the numerology used can be selected ndently of the frequency band although it is assumed that a very low subcarrier spacing will not be used at very high carrier frequencies.

In Figure 10, some ate carrier spacings are illustrated with respect to the frequency and cell range. In Table 1, further details are ed on corresponding time durations for some candidate carrier spacings.

Subcarrier spacing in OFDM symbol Cyclic prefix length Total symbol kHz duration in µs in µs duration in µs 66.67 4.76 71.43 33.33 2.38 35.71 60 16.67 1.19 17.86 120 8.33 0.60 8.93 Table 1 ACK/NACK feedback is used, e.g., in LTE, by the intended receiving node to inform a sending node that its transmission has been or has not been successfully received. The ACK/NACKs may be itted in response to DL by UE (via UL control channel or data channel) or eNB (via PHICH) in response to UL, respectively. For the HARQ ck transmitted by the UE in UL, in general, it is expected that in FDD the UE transmits the feedback in subframe (n+4) for the DL reception in subframe n. For TDD, the relation is also pre-defined but depends on the TDD configuration. In HD-FDD, the timing on between reception of data at the UE and transmission of HARQ A/N in the uplink is also pre-defined e.g. in NB-IoT the ACK/NACK is sent in me n+12.

For NR (or at least for some configurations/setups), one of the important functional ements is a reduced latency, which may also imply, e.g., faster feedback. Several solutions enabling faster feedback were discussed.

For example, it is foreseen that an ACK/NACK feedback of a transport block sent in DL during a slot can already be sent back at the end of the same slot, see Figure 11, where Tproc is the UE processing time (the time required in the UE to decode and prepare the ACK/NACK), and Tp is the propagation time. One OFDM symbol incl. cyclic prefix is ��æ long. Note that a slower n of the fast ACK/NACK feedback is also discussed in 3GPP where the UL slot depicted in Figure 11 does not contain ACK/NACK feedback of the DL in the current slot but of a previous slot.

Figure 11 shows a DL-heavy slot with ACK/NACK feedback at the end. The duration between DL-end UL-start is determined by the UE sing time. Three OFDM symbol durations are needed to fit the UL channel structure including required processing time in the UE.

If the NR carrier is to be deployed in the same band as an LTE TDD carrier and due to interference, the UL-DL must be aligned and the ACK/NACK feedback as shown in Figure 11 cannot be used since LTE has no matching frame ure. In this case, an alternative ACK/NACK ck structure must be used. The ative ACK/NACK feedbacks structure resembles a more “regular” UL transmission, e.g. on scheduled resources, see Figure 12. In Figure 12 both ACK/NACK feedback mechanisms are shown. More specifically, in Figure 12 the first two transmissions are acknowledged by an CK feedback coming immediately at the end of the transmission. The last transmission is acknowledged by feedback transmitted in a more ar” UL transmission and is more suitable if coexistence with LTE is required.

The presently described concept of performing a selecting process for selecting a relative timing for sending the second transmission from among a plurality of predetermined relative timing choices can be advantageously applied in the above io. In other words, the node can be made more flexible by providing it with the arrangement for performing a ing s for selecting a relative timing for sending the second transmission from among a plurality of predetermined relative timing choices, as it can then choose e.g. between the fast feedback at the end of the same slot as a first relative timing choice and the “regular” UL transmission on a resource scheduled in a subsequent slot.

Fig. 13, 14 and 15 show another type of scenario in which the presently described t may be advantageously d. In the scenarios of Fig. 13, 14 and 15, the access node (e.g. an eNB) sends a first transmission (DL ctrl in the figure) which grants an end node (e.g. a UE) the resources to transmit UL transmission for a specific period of time (a resource ling). If the response is to be sent in the same slot, the UE must take into account the propagation delay, and transmit the UL transmission such that the UL transmission is received by the eNB before the next transmission (DL in the figure). The last symbol transmitted by the UE is received right before the DL transmission starts again. There is a need for the UE to start transmitting as soon as possible, in order to transmit every symbol of the UL ission within the scheduled resource grant.

Fig. 13 shows a resource scheduling io in which the propagation delay (and thus timing advance) of ications between the access node and an end node is reduced (because the distance from base station to UE is small, e.g. in a small cell). In this io, the UE receives a resource scheduling DL transmission. The UE processes the received ation and prepares an UL transmission. The UE initiates the UL transmission, taking into account the propagation delay, or the timing advance, such that the UL transmission is received by the eNB at an adequate time. In the io of Fig. 13, the UE has enough time to process the resource scheduling DL transmission (DL ctrl) and start transmitting the UL transmission such that every symbol of the UL transmission is received by the eNB during the scheduled resource grant. In other words, the time between the reception of the DL ctrl at the UE and the start of the UL transmission is larger than the time needed for the UE to process, prepare and start transmitting the UL transmission.

Fig. 14 shows a resource scheduling io in which the propagation delay (and thus timing advance) of communications between the access node and an end node is large. In this scenario, the UE received the resource scheduling DL transmission, but does not have enough time to process the information and prepare the UL ission before the time when the UL transmission needs to start so that every symbol of the UL transmission is received by the eNB during the scheduled resource grant.

Fig. 15 shows a possible on to the problem encountered in Fig. 14. In Fig. 15, the UL transmission is delayed (and shortened) until the next suitable time which would allow the UL transmission to be received by the eNB appropriately. A drawback of the solution in the scenario of Fig. 15 is that a large overhead is created, whereby the channel is unused for a longer period of time. An alternative would be to adjust the period of resources d to the UE for a UL transmission, such that the resource grant is valid for one or more additional slot or symbol, if necessary. In which case, the DL transmission would resume at a later slot or symbol.

The shown scenarios indicate how the timing advance or cell size can be used as communication condition on the basis of which the selecting s can select a relative timing choice. For example, if the TA is small, then the selecting process may be arranged to select a fast uplink response, as e.g. shown in Fig. 13, s if the TA exceeds a predetermined limit, then the selecting process may be arranged to select a slower relative timing choice, e.g. similar to the alternative mechanism shown in Fig. 12 or Fig. 15.

In the following, further technical aspects will be disclosed.

I. Regarding Radio ce Management (RRM) requirements for NR, the following is disclosed: Discussion Multiple numerologies In [1], RAN4 has been agreed: o Evaluate decisions made in /3 August meeting round and investigate likely impacts to future RAN4 RRM requirements and testing. Topics may include:  Measurement gaps for NR  Impact on RRM requirements from: • Flexibility of subcarrier g and multiple numerologies In this section, we further discuss the highlighted topics from the WF in [1].

In RAN1#86, the following new agreements in relation to numerology were achieved: • NR logy scalability should allow at least from [3.75 kHz] to 480 kHz rier spacing • Specification supports multiplexing numerologies in TDM and/or FDM within/across (a) subframe duration(s) from a UE perspective • A UE has one reference numerology in a given NR carrier which defines subframe duration for the given NR carrier From the above, it is evident that the number of numerologies in NR is not limited to a just few options. This, in ation with other factors, e.g., bandwidths, may make it impossible to explicitly specify RRM requirements for each numerology or each combination involving a numerology. An alternative could be to specify RRM requirements for groups of r numerologies. For time-related RRM requirements, e.g., handover delays, measurement periods, etc., the requirements could also be ied in a generic way, if the requirement or its part scales with the logy (which may not be necessarily always possible, e.g., when the RS density does not scale or the UE/gNB processing time do not scale).

• Proposal 1: Consider grouping of numerologies in RRM requirements or specifying requirements in a generic way with respect to numerology, e.g., when the requirements or its parts scale with numerology.

Numerology may change in frequency or time in NR on one hand, but one the other hand not all the UEs will be ting all numerologies and perhaps the numerology at least in some requency ces or at least for the basic signals will be more static.

• Proposal 2: The minimum set of RRM requirements need to be defined for scenarios with ally d numerology being the same in all or at least some time resources, which should be at least the starting point. Next, requirements for scenarios with dynamic or mixed numerologies should be specified in a complementary way.

Numerology impact on timing-related requirements The support of multiple numerologies and multiplexing different numerologies in time and/or frequency domain may also have impact on timing related aspects, e.g., the amount of timing adjustment at a time, accuracy, timing adjustment delay. Also, in addition to the dependency of subframe length even the time unit (in LTE, corresponding to Ts specified in 36.211) may not be a single value any more in NR.

• Observation 1: Timing related requirements will depend on numerology Another -related aspect which may need to also account for the support of multiple numerologies is the differentiation between synchronous and asynchronous scenarios which in turn determines which requirements apply, e.g., whether the UE is performing ements on synchronous or ronous cells which are using different numerologies and corresponding time scales.

• Observation 2: RAN4 needs to define how to differentiate synchronous and asynchronous operation when multiple logies are used.

CA scenarios with different numerologies CA of carriers with different numerologies was discussed in other groups, e.g. in RAN2#95, where the ing was concluded: • From RAN2 point of view, aggregation of carriers with ent logies should be supported in NR. (Modelling aspects such as whether it is a single or multiple MAC entity is FFS) The above scenario may further impact how the timing is adjusted in such carrier ations and how to create TAGs. Another issue that may arise is that with cross-carrier ling with the carriers using different time scales due to different numerologies.

• Proposal 3: RAN4 to discuss the RRM impact of CA scenarios with carriers having different numerologies.

Feedback mechanisms and cross-numerology scheduling In LTE, there is a strict fined time relation between some DL and UL transmissions. For example, for the HARQ feedback transmitted by the UE in UL, in general, it is expected that in FDD the UE transmits the feedback in subframe (n+4) for the DL reception in subframe n.

For TDD, the relation is also pre-defined but depends on the TDD configuration. In HD-FDD, the timing relation between reception of data at the UE and transmission of HARQ A/N in the uplink is also pre-defined e.g. in NB-IoT the CK is sent in subframe n+12. For NR, faster ck mechanisms are being discussed, which has advantages in certain scenarios, but these mechanisms may further depend on numerology of the UL and possibly DL, coverage level, etc. Ultimately, both LTE-like mechanism and fast feedback mechanisms may be supported in NR, depending on the scenarios. Therefore, there may be a need in requirements for the NR feedback mechanisms. Furthermore, some current LTE requirements are measured in terms of CK, but if multiple feedback mechanisms are supported in NR, just g this metric in NR as it is used in LTE may introduce ambiguity in the requirements.

• Proposal 4: Support of multiple feedback mechanisms needs to be considered in NR requirements.

Measurement gaps Many LTE requirements account for measurement gaps, which is likely to happen also in NR.

In LTE, a single duration of 6 ms for UE measurement gaps has been so far standardized.

Furthermore, the measurement gaps are common for all carrier frequencies. In NR, where different numerologies are ted, using common gaps of a single fined length independent of numerology may be not efficient from resource utilization point of view.

Furthermore, even intra-frequency measurement gaps may be needed, e.g., due to transmissions misaligned with t to the center of the bandwidth.

• Proposal 5: In NR, more flexible measurements gap configurations are needed.

Beamforming In [1], RAN4 agreed: o Evaluate decisions made in RAN1/2/3 August meeting round and igate likely impacts to future RAN4 RRM ements and testing. Topics may include:  Necessary metric and requirements for beam management measurements  Impact on RRM requirements from: • a configuration, e.g., r the requirements are the same or ent for measurements based on beamforming and omni-directional antennas, and applicability of beamforming related requirements for different frequency ranges.

 Impact of NR rming techniques, and how to specify generic requirements covering eg , digital, or hybrid beamforming The topics highlighted above are further discussed in this section.

Some related RAN1 agreements: Agreements: Beam management = a set of L1/L2 procedures to acquire and maintain a set of TRP(s) and/or UE beams that can be used for DL and UL transmission/reception, which include at least following aspects: Beam determination= for TRP(s) or UE to select of its own Tx/Rx beam(s).

Beam measurement = for TRP(s) or UE to measure characteristics of received beamformed signals Beam reporting = for UE to report information a property/quality of of beamformed (s) based on beam measurement Beam sweeping = operation of ng a spatial area, with beams transmitted and/or received during a time interval in a predetermined way.

Agreements: The following DL L1/L2 beam management procedures are supported within one or multiple TRPs: • P-1: is used to enable UE measurement on different TRP Tx beams to support selection of TRP Tx beams/UE Rx beam(s) o For beamforming at TRP, it typically includes a intra/inter-TRP Tx beam sweep from a set of different beams o For beamforming at UE, it typically includes a UE Rx beam sweep from a set of different beams o FFS: TRP Tx beam and UE Rx beam can be determined jointly or sequentially • P-2: is used to enable UE measurement on different TRP Tx beams to possibly change inter/intra-TRP Tx beam(s) o From a possibly smaller set of beams for beam refinement than in P-1 o Note: P-2 can be a special case of P-1 • P-3: is used to enable UE measurement on the same TRP Tx beam to change UE Rx beam in the case UE uses beamforming • Strive for the same procedure design for Intra-TRP and inter-TRP beam management o Note: UE may not know whether it is intra-TRP or inter TRP beam • Note: ures P-2&P-3 can be performed jointly and/or multiple times to achieve e.g. TRP Tx/UE Rx beam change simultaneously • Note: Procedures P-3 may or may not have physical layer procedure spec. impact • Support managing le Tx/Rx beam pairs for a UE • Note: Assistance information from another carrier can be studied in beam management procedures • Note that above procedure can be applied to any frequency band • Note that above procedure can be used in /multiple beam(s) per TRP • Note: multi/single beam based initial access and mobility treated within a separate RAN1 agenda item Beam sweeping is one of the a configurations to be used in NR, which make the availability of transmission and/or reception ons time-dependent, e.g., in a ined way. The frequency or icity of the availability is unlikely to be a single fixed number since this would greatly limit network and UE implementations, but likely to make dependent on these parameters the time periods for procedures based on beamformed measurements, e.g., measurement time period, ement reporting delay, etc. The case of beamforming without beam sweeping in time domain or the omni-directional case can then be viewed as a special case resulting in more frequent or even continuous (e.g., every subframe) availability, provided all other factors are the same, e.g., same signal configuration, etc. The time-based requirements may, however, like in LTE, depend on additional ions, e.g., bandwidth, channel ion, interference, etc., and some of these conditions may possibly be more typical for some antenna configurations and less typical for the others, but it is still believed that there is no need in explicit relation of the requirements to antenna/beam urations.

When it comes to the accuracy, the requirements should be transparent to the beam configurations rather than should be determined by traditional factors, e.g., measurement purpose, type of ed signals, signal design and density, bandwidth, etc.

• Proposal 6: In NR, ased requirements are specified in a generic way for different antenna configurations, allowing also for scaling depending on the availability in time of the relevant tx and/or rx beams, e.g., due to beam sweeping.

Accuracy requirements should be arent to beam configurations.

References R4-166735, “Way forward for NR RRM”, Ericsson, Nokia, Intel.

II. Regarding DL HARQ feedback transmission in UL, the following is ed: Introduction Most of the DL HARQ ck transmission schemes ted so far focused on the transmission of DL ACK/NACK at the end of a DL-heavy slot duration (with the ACK/NACK corresponding to the DL ission of the same slot or an earlier slot). Several reasons suggest the need for additional ck transmission scheme, e.g. the UL transmission on at the end of a DL-heavy slot is very short resulting in small coverage. It is important that NR coverage can match LTE coverage in similar conditions, therefore additional DL HARQ feedback transmission scheme is needed. Coexistence with LTE FS2 – where NR and LTE must share the same UL/DL n – is another reason additional feedback transmission scheme is needs.

Discussion In most RAN1 discussions on DL HARQ feedback transmission in UL a rapid HARQ ACK/NACK feedback transmitted either at the end of the same or at the end of a subsequent slot duration is described. See Figure 6 for an illustration. Figure 16 shows how DL HARQ ck is transmitted at the end of a DL-heavy slot duration (“immediate” CK).

A likely outcome of the NR frame structure discussion is a slot length of 7 and/or 14 symbols.

To fit the feedback into a small part at the slot end the UL transmission can obviously only be short, typically one or very few symbols. Depending on the numerology one OFDM symbol has length 67 µs/2á. For ke deployments at least ��=0 (15 kHz) and ��=1 (30 kHz) are interesting options. Feedback transmission over one or few OFDM symbols is much r than the LTE PUCCH transmission duration of 1 ms with accordingly reduced coverage. To match LTE PUCCH link budget, it must be possible to transmit DL HARQ feedback in UL over a duration of around 1 ms. The application of le RX antennas in the eNB allows shorter ission durations, however, we believe it is important that NR matches LTE coverage even for similar eNB antenna arrangements.

Observation 1: To match LTE PUCCH link budget, it should be possible to transmit DL HARQ feedback transmissions over approximately 1 ms.

It is envisioned that NR can coexist with LTE FS2 if deployed in the same band. Depending on interference situation this may require same DL/UL pattern in LTE and NR. In such cases it is not possible to transmit DL HARQ feedback at the end of a DL-heavy slot. The UL transmission must be delayed until the next UL opportunity in LTE FS2, see Figure 17.

Figure 17: In coexistence-scenario with LTE TDD, DL HARQ ck transmission must be delayed until next LTE FS2 UL opportunity.

Observation 2: In coexistence-scenario with LTE TDD, DL HARQ feedback must be delayed until next LTE FS2 UL opportunity.

To solve the link budget issue pointed out in Observation 1 and to solve the tence with LTE FS2 an additional DL HARQ feedback transmission scheme is needed in addition to the DL HARQ feedback transmission at the end of a DL-heavy slot duration. al 1: NR must provide DL HARQ feedback transmission scheme in UL enabling similar link budget as LTE PUCCH Format 1a.

Proposal 2: NR must provide DL HARQ feedback transmission scheme enabling coexistence with LTE FS2.

One possible mechanism could be to rely on the gNB polling feedback for outstanding DL HARQ processes and scheduling the feedback transmission similar to a regular UL transmission. By selecting the transmission time, the gNB can obviously ensure d UL transmissions with LTE FS2. To ensure adequate link budget the feedback transmissions may have to extend beyond a slot (especially if a slot is only 7 OFDM symbols or for a numerology with ��>0) . However, also for other reasons we propose in 0 to specify aggregation of multipole slots in UL; the same principle could also be applied here to enable longer transmission durations with improved link budget.

Conclusion In this observation, we propose to define DL HARQ feedback ission schemes in UL that match LTE PUCCH link budget and enable coexistence with LTE FS2. ation 1: To match LTE PUCCH link budget, it should be possible to transmit DL HARQ ck transmissions over approximately 1 ms.

Observation 2: In coexistence-scenario with LTE TDD, DL HARQ ck must be delayed until next LTE FS2 UL opportunity.

Proposal 1: NR must e DL HARQ feedback transmission scheme in UL enabling similar link budget as LTE PUCCH Format 1a.

Proposal 2: NR must provide DL HARQ feedback transmission scheme enabling coexistence with LTE FS2.

References R1-167502, “On multi-subframe ling for uplink transmissions”, Ericsson, RAN1#86, August 2016

Claims (30)

Claims 1.

1. A wireless device for a 3GPP radio ication k, said wireless device being arranged for reception of a first transmission and subsequent sending of a second transmission in response to said first transmission, wherein said wireless device is furthermore arranged to receive from a network node Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for configuring a set of le relative timing ions and a DCI control message for selecting from the configured set, and to perform a selecting process for selecting a relative timing for sending said second transmission from among a plurality of predetermined relative timing choices, wherein the selecting said relative timing for sending said second transmission is done according to the received DCI control message.

2. A ss device according to claim 1, further being arranged to send information associated with the wireless device’s capability of supporting one or more of said plurality of ermined relative timing choices to the network node.

3. A ss device according to claim 2, wherein said information comprises information on one or more numerologies.

4. A wireless device ing to one of the preceding claims, wherein said relative timing is sed in terms of a given number of slots.

5. A wireless device according to any one of the preceding claims, wherein the relative timing s are related to a time difference between receiving the first transmission and sending the second ission..

6. A wireless device according to one of the preceding claims, wherein said ing process is arranged to take into account information associated with one or more communicating conditions of said wireless device, wherein said icating conditions comprise a set of one or more physical layer settings and said set comprises at least a numerology, and wherein said information associated with one or more communicating conditions comprise one or more of a time of arrival, a timing advance, a round-trip delay time, a reference signal time difference, a synchronization signal time difference, an Rx-Tx time difference, and a propagation delay.

7. A wireless device ing to one of the preceding , wherein said first transmission is a downlink transmission that comprises scheduling information and said second transmission is an uplink ission that comprises data, over a resource allocated with the scheduling information.

8. A ss device according to claim 7, wherein said first transmission is over a Physical Downlink Control Channel, PDCCH, and said second transmission is over a Physical Uplink Shared Data Channel, PUSCH.

9. A wireless device according to one of claims 1 to 6, wherein said first transmission is a downlink transmission that comprises data and said second transmission is an uplink transmission that comprises HARQ feedback information related to a receipt of said data.

10. A wireless device according to claim 9, wherein said first transmission is over a al Downlink Shared Channel, PDSCH, and said second transmission is over a Physical Uplink Control Channel, PUCCH.

11. A network node for a 3GPP radio communication network, said network node being arranged for sending of a first transmission and subsequent receiving of a second transmission in response to said first ission, wherein said network node is furthermore arranged to perform a selecting process for selecting a ve timing for sending said second ission from among a plurality of predetermined relative timing choices, and to send to a wireless device Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control e signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set.

12. A network node according to claim 11, further being ed to e from the wireless device information associated with the wireless device’s capability of supporting one or more of said plurality of predetermined relative timing choices.

13. A network node ing to claim 12, wherein said information comprises information on one or more numerologies.

14. A network node according to one of the preceding claims, wherein said relative timing is expressed in terms of a given number of slots.

15. A network node according to any one of the preceding claims, wherein the relative timing s are related to a time ence between receiving the first transmission and sending the second transmission.

16. A network node according to one of the preceding claims, wherein said selecting process is arranged to take into account information associated with one or more communicating ions of said wireless device, wherein said icating conditions comprise a set of one or more physical layer gs and said set comprises at least a numerology, and wherein said information associated with one or more icating conditions comprise one or more of a time of arrival, a timing e, a round-trip delay time, a reference signal time difference, a synchronization signal time difference, an Rx-Tx time difference, and a propagation delay.

17. A network node according to one of the preceding claims 11 to 16, wherein said first transmission is a downlink transmission that comprises scheduling information and said second transmission is an uplink transmission that comprises data, over a resource allocated with the scheduling information.

18. A network node according to claim 17, wherein said first transmission is over a Physical Downlink Control l, PDCCH, and said second transmission is over a Physical Uplink Shared Data Channel, PUSCH.

19. A network node according to one of claims 11 to 16, wherein said first transmission is a downlink transmission that comprises data and said second ission is an uplink transmission that comprises HARQ feedback information related to a receipt of said data.

20. A network node according to claim 19, wherein said first transmission is over a Physical Downlink Shared Channel, PDSCH, and said second transmission is over a Physical Uplink Control Channel, PUCCH.

21. A method of operating a wireless device for a 3GPP radio communication network, comprising: receiving, from a k node, Radio Resource Control, RRC, and Downlink Control Information, DCI, control message ing, wherein said RRC and DCI control message ing comprises an RRC control message for configuring a set of possible relative timing selections and a DCI control message for selecting from the configured set, receiving a first transmission; selecting a relative timing for sending a second transmission in response to said first transmission, the relative timing being selected from among the configured set, and wherein the selecting said relative timing for sending said second transmission is done ing to the received DCI control message; and sending a second transmission in accordance with the selected relative timing.

22. A method of operating a k node for a 3GPP radio communication k , comprising: sending a first transmission to a wireless device; and ing a second ission in response to said first transmission, n said method also comprises selecting a relative timing for sending said second transmission in se to said first transmission, the relative timing being selected from among a plurality of predetermined ve timing choices, and further comprising: sending to said wireless device Radio Resource Control, RRC, and Downlink Control Information, DCI, control message signaling, wherein said RRC and DCI control message signaling comprises an RRC control message for configuring a set of possible relative timing selections and a DCI l message for selecting from the configured set.

23. A method according to one of claims 21 or 22, wherein said relative timing is expressed in terms of a given number of slots.

24. A method according to one of claims 21 to 23, wherein the relative timing choices are related to a time ence between receiving the first ission and sending the second transmission.

25. A method according to one of claims 21 to 24, wherein said first transmission is a nk transmission that comprises data and said second transmission is an uplink transmission that comprises HARQ feedback information related to a receipt of said data.

26. A method according to claim 25, wherein said first transmission is over a Physical Downlink Shared Channel, PDSCH, and said second transmission is over a Physical Uplink Control Channel, PUCCH.

27. A wireless device according to claim 1 substantially as herein described with reference to figures 1 – 17 and/or examples.

28. A network node according to claim 11 substantially as herein described with reference to s 1 – 17 and/or examples.

29. A method according to claim 21 substantially as herein described with reference to figures 1 – 17 and/or es.

30. A method according to claim 22 substantially as herein bed with reference to figures 1 – 17 and/or examples. WO 60431