WO2018227925A1

WO2018227925A1 - Methods and devices associated with improvements in or relating to hybrid automatic repeat requests in new radio

Info

Publication number: WO2018227925A1
Application number: PCT/CN2017/118427
Authority: WO
Inventors: Guang Liu
Original assignee: Jrd Communication (Shenzhen) Ltd
Priority date: 2017-06-16
Filing date: 2017-12-26
Publication date: 2018-12-20
Also published as: GB201709614D0; CN111034083A

Abstract

A method and system for enabling access to services provided by a Radio Access Network between first and second wireless communications devices; the method comprising, after the first device has transmitted a transport block at a first transmission time interval to the second device, scheduling for transmission to the second device some or all of the transmitted transport block based in part on some or all of the transport block having not been received at the second device.

Description

Methods and devices associated with improvements in or relating to Hybrid Automatic repeat requests in New Radio

Technical Field

Embodiments of the present invention generally relate to wireless communication systems and in particular to devices and methods for enabling a wireless communication device, such as a User Equipment (UE) or mobile device to access a Radio Access Technology (RAT) or Radio Access Network (RAN) , particularly but nor exclusively in conjunction with improvements in or relating to Hybrid Automatic repeat requests in New Radio.

Background

Wireless communication systems, such as the third-generation (3G) of mobile telephone standards and technology are well known. Such 3G standards and technology have been developed by the Third Generation Partnership Project (3GPP) . The 3 ^rd generation of wireless communications has generally been developed to support macro-cell mobile phone communications. Communication systems and networks have developed towards a broadband and mobile system.

The 3rd Generation Partnership Project has developed the so-called Long Term Evolution (LTE) system, namely, an Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, (E-UTRAN) , for a mobile access network where one or more macro-cells are supported by a base station known as an eNodeB or eNB (evolved NodeB) . More recently, LTE is evolving further towards the so-called 5G or NR (new radio) systems where one or more cells are supported by a base station known as a gNB.

A transport block (TB) is a set of information bits to be transmitted in one Transmission Time Interval (TTI) and its size is specified by transport block size (TBS) . TBS of LTE can be found in Table 7.1.7.2.1-1 in 3GPP TS 36.213. The beginning part of the table shown in Table 1 below.

Table 7.1.7.2.1-1: Transport block size table (dimension 34×110)

Table 1

N _PRB is the number of allocated Physical Resource Blocks (PRBs)and I _TBS is an index of TBS which can be mapped to the used Modulation Coding Scheme(MCS). In other words, the TBS value is determined by MCS and the number of scheduled PRBs.

A code block (CB) is a subset of transport block (TB)information bits that are protected by a separate cyclic redundancy check (CRC)and there could be several CBs in each TB. The CB size is limited by a pre-defined maximum value so when the TBS increases, the number of CBs increases too. A few CBs can be further grouped into a code block group (CBG). An illustration can be found in figure 1.

The standards define agreements and then work towards resolving the issues related with those agreements. According to the latest agreements, the number of CBG is pre-determined and the number of CBs per CBG is adjusted according to the TBS.

For grouping CB(s) into CBG(s), following is adopted. With indicated number of CBGs, the number of CBs in a CBG changes according to TBS. Other points which remain open for further study are: for the case of re-transmission or the case when the number of CBs is smaller than the indicated number of CBG; and “indicated” is realized by RRC, MAC, L1 signalling.

In LTE, TB is the basic unit for Ack/Nack feedback, so if one TB is incorrectly received, a Nack will be indicated and if one TB is correctly received, an Ack will be indicated. The whole TB indicated by a Nack is retransmitted. The lesson learned from LTE is that it is highly inefficient to transmit the whole TB because normally not all CBs in a TB are incorrect. As a result,it has been agreed by 3GPP to support CBG level Ack/Nack feedback to improve the efficiency.

Note that it is precluded to have retransmitted CBG (s) and new CBGs (from a new TB) within the same TB according to the agreements in RAN1#88b. This means no new data can be transmitted together with a retransmission even if there are resources available. This could limit the throughput of the serving User Equipment (UE) but the resource that are realised with CBG based retransmission can benefit other UEs.

It has also been agreed that CBG-based transmission with single/multi-bit HARQ-ACK feedback as supported in Rel-15, shall have the following characteristics:

· Only allow CBG based (re) -transmission for the same TB of a HARQ process;

· CBG can include all CB of a TB regardless of the size of the TB -In this case, UE reports single HARQ ACK bits for the TB;

· CBG can include one CB; and

· CBG granularity is configurable.

NR is going to support eMBB (enhanced Mobile Broadband) and URLLC (Ultra Reliable Low Latency Communication) multiplexing, and to meet the very short latency requirement of URLLC services, resources from ongoing eMBB transmissions may be pre-empted and used to transmit URLLC packets. Bursty URLLC transmission in the serving cell may also cause bursty interference to the neighbour cells.

An example is given in figure 2. Without URLLC (left half of Figure 2) , a downlink (DL) TB of eMBB could be scheduled by DCI and due to strong interference or deep channel fading, one or more CBGs may be incorrectly received. A CBG based HARQ-Ack/Nack in the uplink control information (UCI) informs the gNB which CBG (s) needs to be retransmitted and these CBG (s) is retransmitted in a coming TTI. The UE can combine soft information from both receptions to improve the performance since both include useful information. With URLLC (right half of Figure 2) , a URLLC packet may arrive after the downlink control information (DCI) so it cannot be scheduled in the same way as an eMBB packet and the gNB may pre-empt a block of physical resource from ongoing eMBB transmissions for the URLLC transmission. Unlike. With a failure with deep channel fading and/or strong interference, the UE cannot do soft combining because the pre-empted/punctured part has no useful information and soft combining will degrade the performance of HARQ retransmission.

Regarding signalling aspects to support CBG retransmission, an agreement was achieved in RAN1#89 meeting: two options can be used and it is up to the gNB configuration to choose which option.

For DL CBG-based (re) transmission, the following information can be configured to be included in the same DCI: which CBG (s) is/are (re) transmitted; and which CBG (s) is/are handled differently for soft-buffer/HARQ combining.

Further study will determine: how UE behaviour is specified, e.g., part/whole of soft-buffer of indicated CBG (s) is flushed; and timing of CBG-based (re) transmission.

For pre-emption indication, the following considerations are made:

· when configured, the indication tells the UE (s) which DL physical resources has been pre-empted;

· the pre-emption indication is transmitted using a physical, downlink control channel (PDCCH) ; and

· the pre-emption indication is not included in the DCI that schedules the (re) transmission of the data transmission.

·Further study will determine: the granularity of the time and/or frequency resources; what DCI is used; and timing of the pre-emption indication.

Two options are supported by the standards but which option to use is configured for the gNB. One option, called CBG based below, is to indicate which CBG (s) are pre-empted, CBG1 and CBG2 in the example (right half in Figure 2) , and buffered soft information of indicated CBG (s) cannot be used in the soft combining (will be flushed) . The other option, called resource based below, is to indicate the time by frequency resource which is pre-empted, e.g., symbols by PRBs, and buffered soft information from indicated resources cannot be used in the soft combining.

Pre-emption means that a URLLC transmission could happen within the transmission resources of an eMBB transmission with higher power. Puncturing means that the URLLC transmission is replacing the eMBB transmission and it can be understood that puncturing is a specific case of pre-emption with infinite power ratio between URLLC and eMBB transmission.

The option with resource block indication can provide more accurate information for soft combining and it is possible to reuse the soft information of a partial CBG.

However, this option needs an additional signalling field possibly from a group common PDCCH.

The term “Which CBG (s) is/are (re) transmitted” means a transmission indication is included in the DCI to indicate which CBGs are retransmitted and this indication is required by both options. “Which CBG (s) is/are handled differently” means which retransmitted CBG (s) need to flush the buffer before soft combining and this indication is required only when the CBG based option is configured.

To show the problem, an example is shown in figure 3, with the CBG based option. A TB with four CBGs (CBG0/1/2/3) is transmitted to the UE, and during the transmission, CBG1 is impacted by URLLC pre-emption and CBG3 is impacted by strong interference so both CBGs are incorrectly received. The UE returns the HARQ-Ack/Nack as A/N/A/N, where “A” means Ack, “N” means Nack.

In the retransmission, a retransmission indication is included to indicate which CBG (s) of the original TB is retransmitted, and in this example “0101” indicates CBG1 and CBG3 from the original TB are retransmitted. A buffer indication is included to indicate which of the retransmitted CBG’s buffer needs to be flushed and in this example, [YES NO] indicates the buffer of CBG1 needs to be flushed as it is pre-empted for URLLC transmission while no need to flush the buffer of CBG3 as it is not pre-empted.

It can be observed that the transmission indication size is known by the UE as the number of CBGs is pre-configured but the buffer indication size is variable and unknown as it is determined by the number of incorrect CBGs.

The present invention acknowledges the abovementioned problems and realises the need to address the following issues. Firstly, new transmission of a TB is not covered by the above agreements and for a new transmission, there is no need to include transmission indication and buffer indication. Also new transmission and retransmission may be differentiated by toggling NDI (new data indicator) in the DCI payload, the joint coding of NDI and above-mentioned indications are still open and are addressed by the present invention as will be described below.

The present invention is seeking to solve at least some of the outstanding problems in this domain.

Summary

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

According to a first aspect of the present invention there is provided a method for enabling access to services provided by a Radio Access Network between first and second wireless communications devices, the method comprising: after the first device has transmitted a transport block at a first transmission time interval to the second device, scheduling for transmission to the second device some or all of the transmitted transport block based in part on some or all of the transport block having not been received at the second device.

Preferably, the transport block comprises one or more code blocks which are grouped in one or more code block groups.

Preferably, the step of scheduling comprises scheduling at least one of a code block and a code block group of the transport block for transmission.

Preferably, a transmission indicator is included in a control signal to indicate which code blocks or code block groups of the transport block are transmitted.

Preferably, the transmission indicator is capable of indicating if all incorrect code blocks indicated as a Nack in the last uplink control channel are transmitted.

Preferably, the transmission indicator is capable of indicating if all code block groups of the transport block are transmitted.

Preferably, the transmission indicator further includes a bitmap to indicate which code block groups of the transport block are transmitted.

Preferably, the transmission indicator further includes a second sub-indicator to indicate if Ack/Nack feedback is required for code block groups not indicated for transmission.

Preferably, a buffer indicator is included in the control signal to indicate which buffers of the code block groups need to be flushed.

Preferably, the buffer indicator is capable of indicating that the buffers of all transmitted code block groups need to be flushed.

Preferably, the buffer indicator is capable of indicating that the buffers of all transmitted code block groups do not need to be flushed.

Preferably, wherein the buffer indicator further includes a bitmap to indicate which buffers of code block groups of the transport block need to be flushed.

Preferably, another indicator is used to indicate time/frequency resources which were pre-empted.

Preferably, the another indicator is used by user equipment to flush corresponding buffers.

Preferably, the Radio Access Network is a New Radio/5G network.

According to a second aspect of the present invention there is provided a base station capable of performing the method of another aspect of the present invention.

According to a third aspect of the present invention there is provided a User equipment capable of performing the method of another aspect of the present invention.

According to a fourth aspect of the present invention there is provided a non-transitory computer readable medium having computer readable instructions stored thereon for execution by a processor to perform the method of another aspect of the present invention.

The non-transitory computer readable medium may comprise at least one from a group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, a Programmable Read Only Memory, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory and a Flash memory.

Brief description of the drawings

Further details, aspects and embodiments of the invention will be described, by way of example only, with reference to the drawings. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. Like reference numerals have been included in the respective drawings to ease understanding.

Figure1 is a simplified diagram showing a transport block along with the code block groups, in accordance with the prior art;

Figure2 is a simplified diagram of an illustration of an example URLLC transmission, in accordance with the prior art;

Figure 3 is a diagram showing a CBG based option, in accordance with the prior art;

Figure 4 is a diagram showing a number of different scenarios, according to an embodiment of the present invention;

Figure 5 is a simplified diagram showing a further case, according to an embodiment of the present invention;

Figure 6 is diagram showing an example of messages for case A, according to an embodiment of the present invention;

Figure 7 is simple diagram of an embodiment for cases B, C, and/or D, according to an embodiment of the present invention;

Figure 8 is a further embodiment for case E, according to an embodiment of the present invention;

Figure 9 is a diagram showing an example of messages for case C, according to an embodiment of the present invention; and

Figure 10 is a diagram showing an example of messages for case A, according to an embodiment of the present invention.

Detailed description of the preferred embodiments

Those skilled in the art will recognise and appreciate that the specifics of the examples described are merely illustrative of some embodiments and that the teachings set forth herein are applicable in a variety of alternative settings.

In the present invention, the CBG level retransmission is addressed by assuming the CBG level HARQ-Ack/Nack is supported by the terminals.

This invention relates to DCI joint coding of the above two indications and the NDI, in order to achieve a balance between DCI efficiency and retransmission efficiency. For DCI efficiency, one aspect is to reduce its size as much as possible and another aspect is to avoid variable sizes.

CBG based retransmission can be summarized as below:

URLLC multiplexing is not configured. As such, there is no need to consider pre-emption/puncture. This means “pre-emption indication” in the agreement will not be sent; and “Which CBG (s) is/are handled differently for soft-buffer/HARQ combining” in the agreement will not be sent as not all buffers are flushed by default.

URLLC multiplexing is configured. As such, the gNB further needs to configure which of the following two options is used. There are two possibilities, a first a resource based option if it is configured that “the indication tells the UE (s) which DL physical resources has been pre-empted” , and in this case “Which CBG (s) is/are handled differently for soft-buffer/HARQ combining” in the agreement will not be sent as buffers are handled according the indicated physical resources. The alternative is a CBG based option, in which “Which CBG (s) is/are handled differently for soft-buffer/HARQ combining” in the agreement is no longer required; a second a CBG based option “Which CBG (s) is/are handled differently for soft-buffer/HARQ combining” in the agreement will not be sent as buffers are handled according the indicated physical resources. The alternative is a CBG based option, in which “Which CBG (s) is/are handled differently for soft-buffer/HARQ combining” is sent to guide the buffer handling.

The following discussion is based on the CBG based option, i.e., URLLC multiplexing configured and an indication is used to guide the buffer handling per CBG. Proposals in this invention are given for the CBG based option first but they are applicable for the resource based option with appropriate simplification as will be discussed below.

Referring to figure 4, the DCI signalling design needs to be robust with considering losing any control or data packet. The above example may result in four cases. Case A: retransmission with NDI not toggled; Case B: new transmission with NDI toggled; Case C: subsequent retransmission with NDI not toggled; and Case D: subsequent retransmission with NDI toggled if DCI 2 is lost. Case A and Case C may happen simultaneously, i.e., some CBG errors due to pre-emption and some others due to strong interference.

In addition as shown in figure 5, there is a fifth case as, namely Case E, retransmission with NDI not toggled, in which different handling is required for different incorrect CBGs.

Compare Case B and Case D, it may happen that NDI is toggled but a retransmission is received which will not normally happen in LTE. The different required actions for each case are shown in table 2.

Table 2

The signalling proposals for each case will now be discussed. All the required signalling will normally be included in the DCI.

For all cases, the transmission indication can be divided into two types: a first complete TB transmission, including new transmission and retransmission; and an incomplete TB transmission, including retransmission only. The latter can be further split into two sub-types, namely: complete retransmission according to latest Ack/Nack feedback; and incomplete retransmission, which means not everything indicated as Nack is retransmitted.

For both complete TB transmission and complete retransmission, no detailed transmission indication is required so that the DCI signalling size can be minimized. For others, a detailed transmission indication is required to inform the UE which CBG (s) are transmitted or not.

The buffer indication for all cases will now be considered. The buffer handling has three different actions: flush all buffers of CBGs indicated by the transmission indication; no flush at all; and flush a subset of buffers further indicated by a bitmap. Buffers need to be flushed if the previous transmission was pre-empted. Signalling is required to differentiate all combinations of the transmission indication, the buffer indication and the NDI (new data indicator) . A number of embodiments of the present invention to achieve this are now disc used in further detail. In a first proposal, all three parameters are considered together and sizes are minimized when possible without losing efficiency. The transmission indication includes a prefix plus a T_Bitmap (Transmission Bitmap) , which has a size equal to the number of CBGs per TB pre-configured/indicated by the gNB to the UE (so it is known by both) . The buffer indication includes a prefix plus a B_Bitmap (Buffer Bitmap) , which has a size equal to the number of CBGs if a complete TB is transmitted or the number of “1” in the T_Bitmap if an incomplete TB is transmitted. The details of the first proposal is shown also in table 3 below

Table 3

The messaging of this first proposal in case A is further illustrated in Figure 6. Depending on the gNB’s choice, three possible examples may happen.

In example 1, the gNB may choose to retransmit all incorrect CBGs reported by the UE, and transmission indication is set to “01” from which the UE knows that all missing CBGs are retransmitted. The handling of buffer depends on which pre-emption indication is configured, i.e., no flush if CBG based pre-emption indicator is configured or flush according to the resource based pre-emption indicator.

It should be noted that this example 1, could be very useful to support retransmission with granularity less than one CBG and the principle is to retransmit whatever granularity achieved by the CBG based HARQ-Ack/Nack.

In example 2, if the above UCI0 is lost, the gNB may choose to retransmit the whole TB after a period which is too long. This results in no Ack/Nack feedback being received from the UE and since no pre-emption has happened, the buffer indication is set to “01” from which the UE knows that no buffer needs to be flushed.

In example 3, if there is not enough resources, for example, due to multiplexing with other UEs or reduced MCS, the gNB may choose to retransmit one or more incorrect CBGs. This is preferable than retransmitting all of them first and leaving others to be retransmitted in a later TTI (s) . As a result, the transmission indication is set to “00 + 010” to indicate that the middle CBG is transmitted while all others are not.

Referring now to figure 7, the first proposal with cases B, C and D is presented. For Case D, DCI2 is lost and nothing is buffered for the new TB so the UE just ignores the buffer indication and does not flush any buffer. If DCI 2 is not lost (Case C) , CBGs received together with DCI2 are buffered and all corresponding buffers are flushed when DCI3 is received with buffer indication “00” . For Case B, the UE just assumes this is a new TB and ignores the buffer indication.

A second proposal will now be discussed in which “Complete TB transmitted” in the first proposal by a T_Bitmap with all “1” s, and accordingly, the first proposal can be further simplified as Option 2 below. It should be noted that the T_Bitmap could be quite big when the number of CBGs pre-configured/indicated is not small which will result in a much bigger DCI in average than the first proposal. The second proposal is shown in more detail in table 4.

Table 4

A third proposal will now be described in which the “Buffer flushed according to B_Bitmap” in the first and second proposals can be merged to “Flush all buffers” . This simplification may influence the retransmission efficiency by giving up soft combining in Case E. This means that even if a small fraction of the transmitted TB was pre-empted, and the gNB can only choose to indicate completely either no soft combining or soft combining with pre-empted resources. In other words, reception is polluted with severe impact on soft combining performance.

Tables 5 and 6 below show the respective versions of the third proposal based on respectively the first and second proposals.

Table 5

Table 6

So as stated above, Option 3A has the minimum DCI in average, Option 3B has the most simplified signalling but both lose the soft combining gains in Case E. Option 1 and Option 2 can support, for each CBG, soft combining as the buffer bitmap, B_Bitmap, will indicate to need combine those CBGs not impacted by pre-emption.

A fourth proposal will now be discussed, which is a signalling proposal with resource-based option configured. When the resource based indicator is configured, there is no need to include the buffer indication in the DCI and as all buffers can be handled according to this resource based pre-emption/puncture indicator.

As illustrated in figure 8, an end indicator at the end of the TTI will indicate the resources impacted by pre-emption and corresponding reception in the buffer from the impacted resources should be deleted. From this indicator, the UE knows exactly which part of its buffer needs to be flushed and which part does not.

In that case, both Proposal 3A and 3B are not applicable but both Proposal 1 and Proposal 2 can be simplified as shown in tables 7 and 8 respectively below.

Table 7

Table 8

The issue of T_Bitmap optimization to support CBG based HARQ-Ack/Nack will now be discussed. CBG based HARQ-Ack/Nack returns the detailed Ack/Nack bits to the gNB so that the gNB can do CBG level retransmission as addressed in this invention. One open topic of CBG based HARQ-Ack/Nack is to decide if the Ack/Nack bit of a CBG not indicated for transmission should be transmitted or not.

For downlink data transmission with CBG based (re) transmission, the number of CBG HARQ ACK bits for a TB is at least equal to the number of CBGs indicated or implied for transmission. There are a number of outstanding issues such as whether “indicated or implied” is realized by RRC, MAC, L1 signalling, or implicitly derived; whether HARQ ACK feedback on one channel for the case of multiple TBs is required; and what to do as a fall back position. One important outstanding issue is whether or not the UE transmits HARQ ACK bits for CBGs not indicated or implied for transmission. This issue will now be considered.

In Case C shown in figure 9, CBG0 is received correctly with DCI2, and after DCI 3, all three DCIs are correctly received. CBG0 is not indicated for transmission in DCI3 so the question is if CBG0’s Ack/Nack bit should be transmitted in UCI2 or not? In this case, it should clearly be transmitted as it is not transmitted before and the gNB is waiting for feedback.

In case A with Example 2 as shown in figure 10, CBG1 is transmitted while CBG0 and CBG2 are not indicated for transmission. Should the Ack/Nack bits of CBG0 and CBG2 be included in UCI1? In this case, it should not be included as both both Ack/Nack bits were transmitted in UCI0 and after that, no further retransmission was received so far. For CBG2, it may be retransmitted in a later TTI so no Ack/Nack feedback is expected by the gNB or it was already retransmitted but not received by the UE so an Ack/Nack feedback is expected by the gNB, only the gNB knows.

As a result, it is proposed to add another indicator to further indicate if an Ack/Nack feedback is expected by the gNB. Since the Ack/Nack bits of the CBGs indicated for transmission must be transmitted so this feedback indicator is only required for those not indicated for transmission.

The new T-Bitmap of Error! Reference source not found. is given in table below:

0 1 (Ack/Nack bit required)

1

The new T-Bitmap of Error! Reference source not found. is given in table below:

From the above proposals and examples an efficient means of handling re-transmission is illustrated and described. The present invention applies to the HARQ process and could equally apply to the ARQ processes.

Although not shown in detail any of the devices or apparatus that form part of the network may include at least a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the method of any aspect of the present invention. Further options and choices are described below.

The signal processing functionality of the embodiments of the invention especially the gNB and the UE may be achieved using computing systems or architectures known to those who are skilled in the relevant art. Computing systems such as, a desktop, laptop or notebook computer, hand-held computing device (PDA, cell phone, palmtop, etc. ) , mainframe, server, client, or any other type of special or general-purpose computing device as may be desirable or appropriate for a given application or environment can be used. The computing system can include one or more processors which can be implemented using a general or special-purpose processing engine such as, for example, a microprocessor, microcontroller or other control module.

The computing system can also include a main memory, such as random access memory (RAM) or other dynamic memory, for storing information and instructions to be executed by a processor. Such a main memory also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor. The computing system may likewise include a read only memory (ROM) or other static storage device for storing static information and instructions for a processor.

The computing system may also include an information storage system which may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a compact disc (CD) or digital video drive (DVD) read or write drive (R or RW) , or other removable or fixed media drive. Storage media may include, for example, a hard disk, floppy disk, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by media drive. The storage media may include a computer-readable storage medium having particular computer software or data stored therein.

In alternative embodiments, an information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, a removable storage unit and an interface , such as a program cartridge and cartridge interface, a removable memory (for example, a flash memory or other removable memory module) and memory slot, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to computing system.

The computing system can also include a communications interface. Such a communications interface can be used to allow software and data to be transferred between a computing system and external devices. Examples of communications interfaces can include a modem, a network interface (such as an Ethernet or other NIC card) , a communications port (such as for example, a universal serial bus (USB) port) , a PCMCIA slot and card, etc. Software and data transferred via a communications interface are in the form of signals which can be electronic, electromagnetic, and optical or other signals capable of being received by a communications interface medium.

In this document, the terms ‘computer program product’ , ‘computer-readable medium’ and the like may be used generally to refer to tangible media such as, for example, a memory, storage device, or storage unit. These and other forms of computer-readable media may store one or more instructions for use by the processor comprising the computer system to cause the processor to perform specified operations. Such instructions, generally referred to as ‘computer program code’ (which may be grouped in the form of computer programs or other groupings) , when executed, enable the computing system to perform functions of embodiments of the present invention. Note that the code may directly cause a processor to perform specified operations, be compiled to do so, and/or be combined with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions) to do so.

The non-transitory computer readable medium may comprise at least one from a group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, a Programmable Read Only Memory, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory and a Flash memory

In an embodiment where the elements are implemented using software, the software may be stored in a computer-readable medium and loaded into computing system using, for example, removable storage drive. A control module (in this example, software instructions or executable computer program code) , when executed by the processor in the computer system, causes a processor to perform the functions of the invention as described herein.

Furthermore, the inventive concept can be applied to any circuit for performing signal processing functionality within a network element. It is further envisaged that, for example, a semiconductor manufacturer may employ the inventive concept in a design of a stand-alone device, such as a microcontroller of a digital signal processor (DSP) , or application-specific integrated circuit (ASIC) and/or any other sub-system element.

It will be appreciated that, for clarity purposes, the above description has described embodiments of the invention with reference to a single processing logic. However, the inventive concept may equally be implemented by way of a plurality of different functional units and processors to provide the signal processing functionality. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organisation.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. The invention may optionally be implemented, at least partly, as computer software running on one or more data processors and/or digital signal processors or configurable module components such as FPGA devices. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term ‘comprising’ does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by, for example, a single unit or processor. Additionally, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, the inclusion of a feature in one category of claims does not imply a limitation to this category, but rather indicates that the feature is equally applicable to other claim categories, as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular, the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, references to ‘a’ , ‘an’ , ‘first’ , ‘second’ , etc. do not preclude a plurality.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term ‘comprising’ or “including” does not exclude the presence of other elements.

Claims

A method for enabling access to services provided by a Radio Access Network between first and second wireless communications devices, the method comprising: after the first device has transmitted a transport block at a first transmission time interval to the second device, scheduling for transmission to the second device some or all of the transmitted transport block based in part on some or all of the transport block having not been received at the second device.
The method of claim 1, wherein the transport block comprises one or more code blocks which are grouped in one or more code block groups.
The method of claim 2, wherein the step of scheduling comprises scheduling at least one of a code block and a code block group of the transport block for transmission.
The method of claim 2 or claim 3, wherein a transmission indicator is included in a control signal to indicate which code blocks or code block groups of the transport block are transmitted.
The method of claim 4, wherein the transmission indicator is capable of indicating if all incorrect code blocks indicated as a Nack in the last uplink control channel are transmitted.
The method of claims 4 or claim 5, wherein the transmission indicator is capable of indicating if all code block groups of the transport block are transmitted.
The method of any one of claims 4 to 6, wherein the transmission indicator further includes a bitmap to indicate which code block groups of the transport block are transmitted.
The method of any one of claims 4 to 7, wherein the transmission indicator further includes a second sub-indicator to indicate if Ack/Nack feedback is required for code block groups not indicated for transmission.
The method of any one of claims 4 to 8, wherein a buffer indicator is included in the control signal to indicate which buffers of the code block groups need to be flushed.
The method of claim 9, wherein the buffer indicator is capable of indicating that the buffers of all transmitted code block groupsneed to be flushed.
The method of claim 9, wherein the buffer indicator is capable of indicating that the buffers of all transmitted code block groupsdo not need to be flushed.
The method of any one of claims 9 to 11, wherein the buffer indicator further includes a bitmap to indicate which buffers of code block groups of the transport block need to be flushed.
The method of any one of claims 4 to 12, wherein another indicator is used to indicate time/frequency resources which were pre-empted.
The method of claim 13, wherein the another indicator is used by user equipment to flush corresponding buffers.
The method of any one of the preceding claim wherein the Radio Access Network is a New Radio/5G network.
A user equipment, UE, apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the method as claimed in any one of claims 1-15.
A base station, BS, apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the method as claimed in any one of claims 1-15
A non-transitory computer readable medium having computer readable instructions stored thereon for execution by a processor to perform the method according toany of claims 1-15.