Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W28/00—Network traffic management; Network resource management
  • H04W28/02—Traffic management, e.g. flow control or congestion control
  • H04W28/0205—Traffic management, e.g. flow control or congestion control at the air interface
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1829—Arrangements specially adapted for the receiver end
  • H04L1/1864—ARQ related signaling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1867—Arrangements specially adapted for the transmitter end
  • H04L1/1887—Scheduling and prioritising arrangements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L47/00—Traffic control in data switching networks
  • H04L47/70—Admission control; Resource allocation
  • H04L47/82—Miscellaneous aspects
  • H04L47/826—Involving periods of time
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/12—Wireless traffic scheduling
  • H04W72/1221—Wireless traffic scheduling based on age of data to be sent

Definitions

• the disclosure relates to a client device and a network access node for reduced preparation time for retransmission of transport blocks. Furthermore, the disclosure also relates to corresponding methods and a computer program.
• 3GPP 5G is the latest generation of cellular mobile communication system succeeding 4G, also known as long term evolution (LTE).
• 4G also known as long term evolution (LTE).
• 5G targets high data rate, reduced latency, energy saving, high system capacity, and massive device connectivity.
• 3GPP 5G also known as new radio (NR)
• NR new radio
• URLLC ultra reliable and low latency communication
• the latency requirement for URLLC services is expressed as the time required for transmitting a message through the network.
• the requirement, one way over the radio access network (RAN), for URLLC has been set to, for some services, a latency of 1 ms combined with a PER of 10e-5.
• An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.
• a further objective of embodiments of the invention is to provide a solution which reduces the retransmission time of transport blocks compared to conventional solutions.
• a client device for a wireless communication system the client device being configured to
• the transmission grant can e.g. be received in a physical downlink control channel (PDCCH) from a network access node, such as a base station. More precisely, such a transmission grant can be an uplink grant in downlink control information (DCI) transmitted in the PDCCH.
• DCI downlink control information
• the transmission grant is received in response to transmission, by the client device, of a scheduling request (SR) to the network access node.
• the preparation time herein are sometimes denoted as a physical uplink shared channel (PUSCH) preparation time in NR systems.
• PUSCH physical uplink shared channel
• An advantage of the client device according to the first aspect is reduced processing time together with limited complexity increase in the client device. Further, by reducing the processing time for retransmissions of transport blocks the latency budget for URLLC services can be fulfilled.
• the second preparation time N 2 2 is shorter than the first preparation time N 2 . 1 .
• An advantage with this implementation form is that the overall latency budget is decreased since retransmission of transport block can be made faster compared to conventional solutions which uses the same preparation time for retransmissions as for initial transmission of a transport block.
• the second preparation time N 2 2 is less than 80 % of the first preparation time N 2 . 1 .
• An advantage with this implementation form is that the overall latency budget is decreased since retransmission can be made faster compared to conventional solutions which uses the same preparation time for retransmissions as for initial transmission of a transport block.
• the second preparation time N 2 2 is less than 60 % of the first preparation time N 2 . 1 .
• At least one of the first preparation time N 2.1 and the second preparation time N 2 2 are dependent on at least one of
• An advantage with this implementation form is that the client device implementation can be made less complex since the first preparation time N 2.1 and the second preparation time N 2 2 are dependent on the above mentioned parameters. Further, since conventional solutions uses the same preparation time for retransmissions as for the first transmission of a transport block shorter preparation time is possible with this implementation form and at the same time being adapted to system configuration. Moreover, in introducing different processing times for an initial transmission and a retransmission only for certain client device capabilities may further reduce the complexity since this requirement is only applicable to certain client devices with tight latency requirements and not for client devices not requiring tight latency requirements.
• the first preparation time N 2.1 and the second preparation time N 2 2 are expressed in number of orthogonal frequency division multiplexing symbols.
• An advantage with this implementation form is that a well-defined preparation timing is defined suitable for wireless communication system using OFDM, such as LTE and NR.
• the uplink data channel can be a PUSCH in NR systems.
• An advantage with this implementation form is that the data is transmitted in a data channel according to defined standard for NR making network access node reception and decoding of prepared transport block following standard procedures.
• the client device is further configured to configured to
• the version may be a redundancy version of a copy of the prepared transport block.
• An advantage with this implementation form is that the client device can reduce the preparation time for the retransmission since most of the pre-processing for a possible retransmission can be made in advance.
• An advantage with this implementation form is that the timing of uplink data transmission is well defined, reducing the complexity in the network access node when decoding the uplink transport block.
• the first time instance T is given by the formula and the second time instance T 2.2 is given by the formula where max(*) is the maximum function, d 2 1 is an indicator function, k is a slot offset, m is the subcarrier spacing, T c is a chip time period, and d 2,2 is a switching time.
• the maximum function in the formulas relates to the maximum of either(N 2:1 + d 2,1 )(2048 + 144) . k2 -m . T c or d 2,2 for the first time instance T 2:1 ; and to the maximum of either ⁇ N 2-2 + d 2,1 )(2048 + 144) . k2 -m . T c or d 2 2 for the second time instance T 2.2 .
• An advantage with this implementation form is that the timing of uplink data transmission is well defined, thereby reducing the complexity in the network access node when decoding the received transport block.
• the client device is further configured to
• the transmission grant is associated with an initial transmission or a retransmission of the transport block based on downlink control information received in a downlink control channel.
• this can be indicated in a new data indicator field of DCI.
• An advantage with this implementation form is that the client device in a simple way can determine whether to perform an initial transmission of a transport block or a retransmission of a transport block.
• a network access node for a wireless communication system the network access node being configured to
• the transmission request herein can for an initial transmission be a request from higher layer to transmit data to a client device, while the transmission request for a retransmission may be a hybrid automatic repeat request (HARQ) negative acknowledgment (NACK) transmitted from a client device in order to request a retransmission of a transport block.
• HARQ hybrid automatic repeat request
• NACK negative acknowledgment
• An advantage of the network access node according to the second aspect is reduced processing time together with limited complexity increase in the network access node. Further, by reducing the processing time for retransmissions of transport blocks the latency budget for URLLC services can be fulfilled.
• the second preparation time N 2 2 is shorter than the first preparation time N 2:1 .
• An advantage with this implementation form is that the overall latency budget is decreased since retransmission can be made faster compared to conventional solutions which uses the same preparation time for retransmissions as well as for an initial transmission of a transport block.
• the second preparation time N 2 2 is less than 80 % of the first preparation time N 2:1 .
• An advantage with this implementation form is that the overall latency budget is decreased since retransmission can be made faster compared to conventional solutions which uses the same preparation time for retransmissions as well as for an initial transmission of a transport block.
• the second preparation time N 2 2 is less than 60 % of the first preparation time N 2:1 .
• An advantage with this implementation form is that the overall latency budget is decreased since retransmission can be made faster compared to conventional solutions which uses the same preparation time for retransmissions as for an initial transmission of a transport block.
• At least one of the first preparation time N 2:1 and the second preparation time N 2 2 are dependent on at least one of
• An advantage with this implementation form is that the network access node implementation can be made less complex since the first preparation time N 2.1 and the second preparation time N 2 2 are dependent on the above mentioned parameters. Further, since conventional solutions uses the same preparation time for retransmissions as for an initial transmission of a transport block shorter preparation time is possible with this implementation form and at the same time being adapted to system configuration.
• the first preparation time N 2:1 and the second preparation time N 2-2 are expressed in number of orthogonal frequency division multiplexing symbols.
• An advantage with this implementation form is that a well-defined preparation time is defined suitable for wireless communication system using OFDM, such as LTE and NR.
• An advantage with this implementation form is that the transport block is transmitted in a data channel, according to defined standard for NR making network access node reception and decoding of prepared transport block following standard procedures.
• network access node further being configured to
• An advantage with this implementation form is that the client device can reduce the preparation time for the retransmission since most of the pre-processing for a possible retransmission can be made in advance.
• perform the first downlink transmission comprises
• An advantage with this implementation form is that the timing of downlink data transmission is well defined, reducing the complexity in the client device when decoding the downlink transport block.
• the first time instance T 2:1 is a function of the first preparation time N 2.1
• the second time instance T 2.2 is a function of the second preparation time N 2 2 .
• An advantage with this implementation form is that different functions may be applied for initial transmission and retransmission and thereby a more flexible solution can be provided in the network access node.
• the above mentioned and other objectives are achieved with a method for a client device, the method comprises
• the method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the client device according to the first aspect.
• an implementation form of the method comprises the feature(s) of the corresponding implementation form of the client device.
• the advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the client device according to the first aspect.
• the above mentioned and other objectives are achieved with a method for a network access node, the method comprises
• an implementation form of the method comprises the feature(s) of the corresponding implementation form of the network access node.
• the invention also relates to a computer program, characterized in program code, which when run by at least one processor causes said at least one processor to execute any method according to embodiments of the invention. Further, the invention also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.
• ROM Read-Only Memory
• PROM Programmable ROM
• EPROM Erasable PROM
• Flash memory Flash memory
• EEPROM Electrically EPROM
• - Fig. 1 shows a client device according to an embodiment of the invention
• FIG. 2 shows a method for a client device according to an embodiment of the invention
• FIG. 3 shows a network access node according to an embodiment of the invention
• FIG. 4 shows a method for a network access node according to an embodiment of the invention
• FIG. 5 shows a wireless communication system according to an embodiment of the invention
• - Fig. 6 shows a timing diagram of control signaling and data transmission of transport blocks in the uplink from a client device to a network access node
• Fig. 7 shows a flow chart of a method according to an embodiment of the invention.
• URLLC traffic requires higher reliability and lower latency than e.g. enhanced mobile broadband (eMBB) traffic.
• eMBB enhanced mobile broadband
• UE user equipment
• gNB packet processing times as much as possible in order to meet the latency requirements of URLLC services.
• UL uplink
• embodiments of the invention utilize the fact that the client device can make pre preparations of uplink transmissions for the retransmission, when such a retransmission is necessary, of a transport block. Hence, the uplink preparation time for retransmission of a transport block can be significantly reduced.
• Embodiments of the invention also relates to corresponding downlink (DL) transmission and retransmission of transport block, mutatis mutandis, performed by a network access node.
• DL downlink
• Fig. 1 shows a client device 100 according to an embodiment of the invention.
• the client device 100 comprises a processor 102, a transceiver 104 and a memory 106.
• the processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art.
• the client device 100 further comprises an antenna or antenna array 1 10 coupled to the transceiver 104, which means that the client device 100 is configured for wireless communications in a wireless communication system. That the client device 100 is configured to perform certain actions can in this disclosure be understood to mean that the client device 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions.
• the client device 100 is configured to receive a transmission grant 502 (see Fig. 5) associated with an uplink transmission of a transport block.
• the client device 100 is further configured perform a first uplink transmission of the transport block based on the transmission grant 502 and a first preparation time N if the transmission grant 502 is associated with an initial transmission of the transport block.
• the client device 100 is further configured perform a second uplink transmission of the transport block based on the transmission grant 502 and a second preparation time N 2 2 if the transmission grant 502 is associated with a retransmission of the transport block.
• the second preparation time N 2 2 is different to the first preparation time N 2 .
• Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a client device 100, such as the one shown in Fig. 1.
• the method 200 comprises receiving 202 a transmission grant 502 associated with an uplink transmission of a transport block.
• the method 200 further comprises performing 204 a first uplink transmission of the transport block based on the transmission grant 502 and a first preparation time N 2:1 if the transmission grant 502 is associated with an initial transmission of the transport block.
• the method 200 further comprises performing 206 a second uplink transmission of the transport block based on the transmission grant 502 and a second preparation time N 2 2 if the transmission grant 502 is associated with a retransmission of the transport block.
• the second preparation time N 2 2 is different to the first preparation time N 2:1 .
• performing the first uplink transmission comprises preparing a transport block for a first uplink transmission (i.e. initial transmission) based on the transmission grant 502 and thereafter to transmit the prepared transport block in an uplink data channel, e.g. PUSCH.
• the client device 100 also stores a version of a copy of the prepared transport block for the first uplink transmission.
• the client device 100 can perform a second uplink transmission (i.e. retransmission) by transmitting the version of a stored copy of the prepared transport block (i.e. a redundancy version of the transport block) in the uplink data channel. Cleary, further retransmissions of a version of the stored copy of the transport block can be performed.
• first uplink transmission can mean to transmit the transport block at a first time instance T 2;1 after reception of the transmission grant 502; whilst to perform the second uplink transmission can mean to transmit the transport block at a second time instance T after reception of the transmission grant 502.
• first time instance T 2;1 and the second time instance T 2.2 can be determined is described more in detail in the following disclosure.
• Fig. 3 shows a network access node 300 according to an embodiment of the invention.
• the network access node 300 comprises a processor 302, a transceiver 304 and a memory 306.
• the processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 known in the art.
• the network access node 300 may be configured for both wireless and wired communications in wireless and wired communication systems, respectively.
• the wireless communication capability is provided with an antenna or antenna array 310 coupled to the transceiver 304, while the wired communication capability is provided with a wired communication interface 312 coupled to the transceiver 304. That the network access node 300 is configured to perform certain actions can in this disclosure be understood to mean that the network access node 300 comprises suitable means, such as e.g. the processor 302 and the transceiver 304, configured to perform said actions.
• the network access node 300 is configured to obtain a transmission request 504 associated with a downlink transmission of a transport block.
• the network access node 300 is further configured to perform a first downlink transmission of the transport block based on the transmission request 504 and a first preparation time N 2:1 if the transmission request 504 is associated with an initial transmission of the transport block.
• the network access node 300 is further configured to perform a second downlink transmission of the transport block based on the transmission request 504 and a second preparation time N if the transmission request 504 is associated with a retransmission of the transport block.
• the second preparation time N 2 2 is different to the first preparation time N 2:1 .
• Fig. 4 shows a flow chart of a corresponding method 400 which may be executed in a network access node 300, such as the one shown in Fig. 3.
• the method 400 comprises obtaining 402 a transmission request 504 associated with a downlink transmission of a transport block.
• the method 400 further comprises performing 404 a first downlink transmission of the transport block based on the transmission request 504 and a first preparation time N 2:1 if the transmission request 504 is associated with an initial transmission of the transport block.
• the method 400 further comprises performing 406 a second downlink transmission of the transport block based on the transmission request 504 and a second preparation time N 2 2 if the transmission request 504 is associated with a retransmission of the transport block.
• the second preparation time N 2 2 is different to the first preparation time N 2:1 .
• the network access node 300 can perform a first downlink transmission by preparing a transport block for the first downlink transmission, i.e. initial transmission, based on the transmission request 504, and thereafter transmits the prepared transport block in a downlink data channel, e.g. PDSCH.
• a downlink data channel e.g. PDSCH.
• the network access node 300 stores a version of a copy of the prepared transport block for the first downlink transmission.
• the network access node 300 can perform a second downlink transmission, i.e. retransmission, by transmitting a redundancy version of the stored copy of the prepared transport block in the downlink data channel.
• the transmission request can for an initial transmission be a request from higher layer to transmit data to a client device.
• the transmission request for a retransmission can be a hybrid automatic repeat request (HARQ) negative acknowledgment (NACK) transmitted from a client device 100 in order to request a retransmission of a transport block, e.g. at reception failure detected in a CRC check.
• HARQ hybrid automatic repeat request
• NACK negative acknowledgment
• the first downlink transmission by the network access node 300 can mean to transmit the transport block at a first time instance T 2;1 after reception of the transmission request 504.
• to perform the second downlink transmission by the network access node 300 can mean to transmit the transport block at a second time instance T 2.2 after reception of the transmission request 504.
• the first time instance T 2;1 is a function of the first preparation time N 2:1
• the second time instance T 2.2 is a function of the second preparation time N 2 2 , respectively.
• a transport block herein can be considered as the information to be transmitted over a radio channel. Hence, different coded versions, i.e. redundancy versions, of the transport block are transmitted in the initial transmission compared to a retransmission of the transport block.
• a transport block can be generated in the medium access control (MAC) layer by concatenating radio link control (RLC) packet data units (PDUs) from different resource blocks.
• MAC medium access control
• RLC radio link control
• PDUs packet data units
• the client device 100 is configured to perform uplink initial transmission and retransmission of one or more transport blocks 520 to the network access node 300 as illustrated in Fig. 5.
• the network access node 300 is configured to perform downlink initial transmission and retransmission of one or more transport blocks 540 to the client device 100.
• Fig. 6 illustrates overall latency considerations of transport block transmission by describing the communication between a client device 100 and network access node 300.
• an initial transmission of a transport block and one retransmission of the transport block is illustrated. More than one retransmission of a transport block can however be performed within the scope of the invention.
• the communication illustrated in Fig. 6 is set in the context of a 3GPP NR system, hence, the terminology used so that a UE corresponds to a client device 100 and a gNB to a network access node 300.
• embodiments of the invention are not limited thereto.
• step I in Fig. 6 data or information is available for uplink transmission at the UE. Therefore, the latency consideration in step I firstly involves UE scheduling request (SR) processing, i.e. the time to prepare transmission of the SR and to determine when the SR can be transmitted to the gNB. Secondly, SR transmission alignment latency is added to the overall latency. The latter latency relates to the fact that the gNB is only monitoring after SRs in pre-defined symbols. Therefore, when the UE has made its decision to transmit the SR to the gNB, it has to wait until the next transmission occasion in order to transmit the SR to the gNB.
• SR UE scheduling request
• step II in Fig. 6 the SR duration is shown and this latency relates the time it takes to transmit the SR from the UE to the gNB in PUCCH.
• a first latency consideration relates to gNB SR processing which is the time it takes to process the SR once the SR has been completely received, decide on a PUSCH grant, schedule and encoded by the gNB.
• the gNB SR processing time may vary significantly.
• a second latency consideration in step III is the PDCCH transmission alignment which relates to the fact that the UE is monitoring the PDCCH only on pre-defined symbols.
• PDCCH blocking occurs which means that the gNB has to wait until the PDCCH blocking has been lifted before transmission of the grant.
• step IV in Fig. 6 the PDCCH duration is shown and this latency relates the time it takes to transmit the transmission grant from the gNB to the UE in the PDCCH.
• step V in Fig. 6 at reception of the grant in the PDCCH the UE prepares the data information into a transport block according to the received grant for an initial transmission to the gNB.
• a first preparation time N for preparing the initial transport block contributes to the latency.
• the first preparation time N can be seen as the time from the end of the PDCCH reception at the UE until the earliest possible time when the PUSCH can be transmitted.
• the maximum allowed PUSCH preparation time is specified in 3GPP NR specification, TS38.214 in terms of OFDM symbols.
• For the aggressive UE cap#2 N2 is ⁇ 5, 5.5, 1 1 ⁇ OFDM symbols for ⁇ 15, 30, 60 ⁇ kHz sub-carrier spacing.
• step V Another factor contributing to the overall latency in step V is the PUSCH transmission alignment which is the time between that the PUSCH has been assembled, encoded and is ready for transmission. Sometimes it is assumed that the PUSCH can be sent immediately after first preparation time N 2:1 , i.e. that this time is equal to zero and does not introduce any extra delay.
• the UE in step V may also store a redundancy version of a copy of the prepared transport block for the initial transmission in a transmission buffer of the UE for possible retransmission of the transport block.
• step VI in Fig. 6 the PUSCH duration for the initial transmission of the transport block is shown and relates to the time it takes to transmit the transport block from the UE to the gNB in PUSCH.
• gNB PUSCH processing has to be considered in overall latency.
• the gNB PUSCH processing latency is the time it takes for the gNB to process the PUSCH once it has been received from the UE. In case of a transmission error, a retransmission grant is scheduled.
• this processing time is split into two components, firstly the PUSCH decoding for which a duration of N1 symbols is assumed, i.e. it is assumed to be the same as PDSCH decoding at the UE side.
• N1 is the specified maximum UE processing time for PDSCH processing based on UE capability #2 and can be predefined, such as defined in 3GPP TS 38.214.
• step VIII in Fig. 6 the transmission of the retransmission grant from the gNB to the UE in the PDCCH is shown.
• the retransmission can be indicated in a dedicated field of a DCI comprised in the PDCCH.
• step IX in Fig. 6 at reception of the PDCCH and the UE determining that a retransmission is requested, the UE prepares for retransmission of the transport block previously transmitted in step VI.
• a second preparation time N 2 2 contributes to the latency, where the second preparation time N 2 2 according to embodiments of the invention is shorter than the first preparation time N 2:1 .
• the second preparation time N 2 2 can be considered as the time from the end of the PDCCH reception at the UE until the earliest possible time when the PUSCH can be transmitted. That the second preparation time N 2 2 is shorter than the first preparation time N can be achieved by the UE transmitting the stored version of the copy of the transport block in step V.
• Another factor contributing to the overall latency in step IX is the PUSCH transmission alignment which is the time between that the PUSCH has been assembled, encoded and is ready for transmission to the gNB.
• step X in Fig. 6 the PUSCH duration for the retransmission of the transport block is shown which is the time duration for retransmission of the transport block from the UE to the gNB in the PUSCH.
• step XI in Fig. 6 gNB PUSCH processing has to be considered in the overall latency.
• the gNB processes the PUSCH, and assuming correctly decoded, the decoded data is fed to higher layers for further processing. It is understood that for the overall latency over the RAN in steps I to XI, also the gNB PUSCH processing has to be considered.
• Fig. 7 shows a flow chart of a method 210 according to a further embodiment of the invention.
• the description of this embodiment is also set in a 3GPP NR context which means that the UE corresponds to a client device 100 and the gNB to a network access node 300.
• step 212 in Fig. 7 the UE monitors PDCCH for DCI.
• the detected DCI comprises an uplink grant which is determined by the UE.
• the UL grant typically consists of information about time-frequency resources, as well as modulation and coding to be used for uplink data transmission.
• the UE obtains information about whether the uplink grant is associated to an initial uplink transmission of a transport block or whether it is associated to a retransmission of the transport block. This information may be obtained from the“new data field indicator” in the DCI indicating whether it is new data or a retransmission that is granted.
• a first preparation time value N is used if it is an initial transmission of the transport block, and a second preparation time value N 2 2 is used if it is a retransmission of the transport block.
• the first preparation time value N is larger than the second preparation time value N 2 2 , i.e. the preparation time is allowed to be longer if it is a first transmission compared to if it is a retransmission of an already transmitted transport block, e.g. due to failed decoding in the gNB.
• the second preparation time N 2 2 is shorter than the first preparation time N 2:1 , such that the second preparation time N 2 2 is less than 80 % of the first preparation time N 2:1 and in some cases less than 60 % of the first preparation time N 2:1 .
• the second preparation time N 2 2 may instead be larger than the first preparation time N 2:1 .
• This may e.g. be the case when the retransmission grant requires significantly re-encoding of a data block. This could happen when the gNB requires a significantly lower code rate than first expected in order to perform a reliable retransmission.
• Another non-limiting example can be when the gNB configures the retransmission on another bandwidth part or another carrier frequency compared to the initial transmission.
• At least one of the first preparation time N 2:1 and the second preparation time N 2 2 is dependent on a size of the transport block to be transmitted. For instance, if the transport block is smaller than a first threshold value, i.e. the entire transport block can be fitted in one code block group, the second preparation time N 2 2 value can be 80 % of the first preparation time N 2:1 value, while if the transport block is large and consist of several code block groups, and only code block groups are retransmitted the relation between the first preparation time N 2:1 and the second preparation time N 2 2 value may different to the first case, e.g. 60 %.
• the first preparation time N value may be 5, while the second preparation time N 2 2 value may be 2.5 expressed in OFDM symbols.
• the first preparation time N 2:1 value may be 5, while the second preparation time N 2 2 value may be 3 expressed in OFDM symbols.
• At least one of the first preparation time N 2:1 and the second preparation time N 2 2 is based on a timing capability of the client device 100.
• the second preparation time N 2 2 value may be only used for certain timing capabilities.
• only the first preparation time N 2:1 value is applicable to first transmissions as well as retransmission, while for other client device capabilities, a first preparation time N 2:1 value is used for initial transmission and a second preparation time N 2 2 value is used for retransmissions.
• Timing capability is often the possibility of a client device to prepare an uplink transmission.
• first preparation time N 2:1 and the second preparation time N 2 2 can be dependent on one or more of the above described parameters: sub-carrier spacing value for the uplink transmission of the transport block, size of the transport block, and timing capability. It is further realized that the first preparation time N 2:1 and the second preparation time N can be expressed in number of OFDM symbols, such as in LTE and NR using OFDM based transmission technology, but may in other embodiments be expressed in time units. Moreover, the first preparation time N 2:1 and the second preparation time N 2 2 for the network access node 300 can also be dependent on one or more of the above described parameters: sub-carrier spacing value for the uplink transmission of the transport block, size of the transport block, and timing capability. Furthermore, the first preparation time N 2 .
• ⁇ and the second preparation time N 2 2 for the client device 100 may also be a dependent on or a function of other parameters, and may in some embodiments be expressed as below, defined in a time after reception of the uplink grant.
• the first uplink symbol in the PUSCH allocation for a transport block, including the DM-RS, as defined by the slot offset K 2 and the start and length indicator SLIV of the scheduling DCI and including the effect of the timing advance, is no earlier than at symbol L 2 , where symbol L 2 is defined as the next uplink symbol with its CP starting after the end of the reception of the last symbol of the PDCCH carrying the DCI scheduling the PUSCH, then the client device 100 shall transmit the transport block.
• performing the first uplink transmission by the client device 100 comprises transmit the transport block at a first time instance T 2;1 after reception of the transmission grant 502, where the first time instance T 2:1 is given by the formula
• T 2:1 max(( N 2:1 + d 2, 1 )(2048 + 144) . k2 -m . T c , d 2,2 ) Eq. (1 )
• max(*) is the maximum function
• N 2 .1 is the first preparation time
• d 2 1 is an indicator function
• k is a slot offset
• m is the subcarrier spacing
• T c is a chip time period
• d 2 2 is a switching time.
• performing the second uplink transmission by the client device 100 comprises transmit the transport block at a second time instance T 2.2 after reception of the transmission grant 502, where the second time instance T 2.2 is given by the formula
• T 2 , 2 ma x((/V 2:2 + d 2,1 )(2048 + 144) . k2 -m T c , d 2,2 ) Eq. (2)
• max(*) is the maximum function
• N 2 2 is the second preparation time
• d 2 1 is an indicator function
• k is a slot offset
• m is the subcarrier spacing
• T c is a chip time period
• d 2 2 is a switching time.
• the maximum function in the formulas according to Eq. 1 and 2 relate to the maximum of either(N 2 :1 + d 2 ,1 )(2048 + 144) . k2 -m . T c or d 2,2 for the first time instance T 2:1 ; and to the maximum of either (N 2 2 + d 2, 1 )(2048 + 144) . k2 -m . T c or d 2 2 for the second time instance T 2.2 .
• the notation herein of the first preparation time and the second preparation time can be different to the one used here, i.e. N 2:1 and N 2 2 .
• Embodiments of the invention can easily be implemented in 3GPP NR specifications, such as TS38.214, section 6.4.
• 3GPP NR specifications such as TS38.214, section 6.4.
• a non-limiting example of mentioned section 6.4 of TS38.214 is given below where an exemplary addition to the specification is given in bold italics, i.e. the text “Furthermore, for UE processing capability 3, N2 is dependent on whether it is the first transmission of the transport block or whether it is a retransmission of the transport block.”.
• the first uplink symbol in the PUSCH allocation for a transport block, including the DM- RS, as defined by the slot offset K2 and the start and length indicator SLIV of the scheduling DCI and including the effect of the timing advance, is no earlier than at symbol Z-2, where L2 is defined as the next uplink symbol with its CP starting
• T proc, 2 max ((N 2 + d 2 1 )(2048 + 144) . k 2 - T c ,d 2, 2 ) afterr the end of the reception of the last symbol of the PDCCH carrying the DCI scheduling the PUSCH, then the UE shall transmit the transport block.
• N2 is based on m of Table 6.4-1 and Table 6.4-2 for UE processing capability 1 and 2 respectively, where m corresponds to the one of ( mDL , muL ) resulting with the largest Tp roc, 2, where the P DL corresponds to the subcarrier spacing of the downlink with which the PDCCH carrying the DCI scheduling the PUSCH was transmitted and muL corresponds to the subcarrier spacing of the uplink channel with which the PUSCH is to be transmitted, and k is defined in subclause 4.1 of [4, TS 38.21 1] Furthermore, for UE processing capability 3, N2 is dependent on whether it is the first transmission of the transport block or whether it is a retransmission of the transport block.
• the first uplink symbol in the PUSCH allocation further includes the effect of timing difference between component carriers as given in [1 1 , TS 38.133].
• the processing time according to UE processing capability 2 is applied if the high layer parameter Capability2-PUSCH- Processing in pusch-Config is configured for the cell and set to enable,
• the transport block is multiplexed following the procedure in subclause 9.2.5 of [9, TS 38.213], otherwise the transport block is transmitted on the PUSCH indicated by the DCI.
• T proc,2 is used both in the case of normal and extended cyclic prefix. Furthermore,
• Tables 6.4-1 and 6.4-2 from the specification is also given below which give PUSCH preparation time for PUSCH timing capability 1 and 2.
• Table 6.4-1 PUSCH preparation time for PUSCH timing capability 1.
• Table 6.4-2 PUSCH preparation time for PUSCH timing capability 2.
• Table 6.4-3 PUSCH preparation time for an initial transmission of a transport block for
• Table 6.4-4 PUSCH preparation time for retransmissions of a transport block for PUSCH timing capability 3.
• the general principles described and explained previously can also be applied to retransmission of one or more transport blocks in case of grant free transmissions.
• the initial transmission of a transport block is taken place at pre-configured time-instances, however retransmissions of transport blocks are scheduled via DCI, as in the grant-based case.
• the timing of retransmission of a transport block is performed based on a second preparation time value of N 2 ⁇ 2 ⁇
• the client device 100 herein, may be denoted as a user device, a User Equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and/or a mobile terminal, is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system.
• the UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability.
• the UEs in this context may be, for example, portable, pocket-storable, hand-held, computer- comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server.
• the UE can be a Station (STA), which is any device that contains an IEEE 802.1 1 -conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM).
• STA Station
• MAC Media Access Control
• PHY Physical Layer
• the UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as New Radio.
• the network access node 300 herein may also be denoted as a radio network access node, an access network access node, an access point, or a base station, e.g. a Radio Base Station (RBS), which in some networks may be referred to as transmitter,“gNB”,“gNodeB”,“eNB”, “eNodeB”,“NodeB” or“B node”, depending on the technology and terminology used.
• RBS Radio Base Station
• the radio network access nodes may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size.
• the radio network access node can be a Station (STA), which is any device that contains an IEEE 802.1 1 -conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM).
• STA Station
• MAC Media Access Control
• PHY Physical Layer
• the radio network access node may also be a base station corresponding to the fifth generation (5G) wireless systems.
• any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method.
• the computer program is included in a computer readable medium of a computer program product.
• the computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive.
• embodiments of the client device 100 and the network access node 300 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the solution.
• means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged togetherfor performing the solution.
• the processor(s) of the client device 100 and the network access node 300 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions.
• CPU Central Processing Unit
• ASIC Application Specific Integrated Circuit
• the expression “processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above.
• the processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

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