WO2021204116A1

WO2021204116A1 - Transmission prioritisation

Info

Publication number: WO2021204116A1
Application number: PCT/CN2021/085678
Authority: WO
Inventors: Umer Salim; Trung Kien Le
Original assignee: TCL Communication Ningbo Ltd
Current assignee: TCL Communication Ningbo Ltd
Priority date: 2020-04-06
Filing date: 2021-04-06
Publication date: 2021-10-14
Anticipated expiration: 2022-10-06
Also published as: CN115699967A; CN115699967B

Abstract

Methods and systems for prioritising transmission of data and control transmissions where the scheduled transmission resources overlap. The UE selects a transmission based on a characteristic of the transmissions, such as priority or message type. In certain situations the two transmissions may be multiplexed for transmission.

Description

Transmission Prioritisation

Technical Field

The following disclosure relates to prioritisation of transmissions, and particularly to the prioritisation of conflicting data and control uplink transmissions.

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) (RTM) . The 3rd 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.

In cellular wireless communication systems User Equipment (UE) is connected by a wireless link to a Radio Access Network (RAN) . The RAN comprises a set of base stations which provide wireless links to the UEs located in cells covered by the base station, and an interface to a Core Network (CN) which provides overall network control. As will be appreciated the RAN and CN each conduct respective functions in relation to the overall network. For convenience the term cellular network will be used to refer to the combined RAN &CN, and it will be understood that the term is used to refer to the respective system for performing the disclosed function.

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. NR is proposed to utilise an Orthogonal Frequency Division Multiplexed (OFDM) physical transmission format.

The NR protocols are intended to offer options for operating in unlicensed radio bands, to be known as NR-U. When operating in an unlicensed radio band the gNB and UE must compete with other devices for physical medium/resource access. For example, Wi-Fi (RTM) , NR-U, and LAA may utilise the same physical resources.

A trend in wireless communications is towards the provision of lower latency and higher reliability services. For example, NR is intended to support Ultra-reliable and low-latency communications (URLLC) and massive Machine-Type Communications (mMTC) are intended to provide low latency and high reliability for small packet sizes (typically 32 bytes) . A user-plane latency of 1ms has been proposed with a reliability of 99.99999%, and at the physical layer a packet loss rate of 10 ^-5 or 10 ^-6 has been proposed.

mMTC services are intended to support a large number of devices over a long life-time with highly energy efficient communication channels, where transmission of data to and from each device occurs sporadically and infrequently. For example, a cell may be expected to support many thousands of devices.

The disclosure below relates to various improvements to cellular wireless communications systems.

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.

There is provided a method of prioritising between data and control transmissions from a UE to a base station where the transmissions have overlapping resources. The control transmission may be HARQ feedback. The UE may prioritise a data transmission over a control transmission if both cannot be transmitted in the scheduled resources. The base station, which does not receive an expected HARQ feedback, assumes the feedback is a NACK. The base station then proceeds appropriately, for example by scheduling retransmission.

The UE may elect to transmit the control or data transmission dependent on the relative priority of the two transmissions. If the two transmissions have equal priority the data transmission may be made. In the case of equal priority the UE’s behaviour may be dependent on the priority level. Where the priority is low the UE may multiplex the control information with the data transmission on PUSCH. Where the priority is high the UE may transmit the data on PUSCH and not the control information. Furthermore, the choice of transmitting data or control information may be based on the type of control information. If the control information is a NACK message the data is transmitted, whereas if the control information is an ACK the control information is transmitted. If multiplexing is enabled the ACK may be multiplexed.

Where feedback is CBG-based feedback, the UE may switch to TB-based feedback prior to transmission of the control information according to the methods described herein.

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.

Figure 1 shows a schematic diagram of exemplary elements of a cellular communications network; and

Figures 2 to 7 show methods of prioritising transmissions.

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.

Figure 1 shows a schematic diagram of three base stations (for example, eNB or gNBs depending on the particular cellular standard and terminology) forming a cellular network. Typically, each of the base stations will be deployed by one cellular network operator to provide geographic coverage for UEs in the area. The base stations form a Radio Area Network (RAN) . Each base station provides wireless coverage for UEs in its area or cell. The base stations are interconnected via the X2 interface and are connected to the core network via the S1 interface. As will be appreciated only basic details are shown for the purposes of exemplifying the key features of a cellular network. A PC5 interface is provided between UEs for SideLink (SL) communications. The interface and component names mentioned in relation to Figure 1 are used for example only and different systems, operating to the same principles, may use different nomenclature.

The base stations each comprise hardware and software to implement the RAN’s functionality, including communications with the core network and other base stations, carriage of control and data signals between the core network and UEs, and maintaining wireless communications with UEs associated with each base station. The core network comprises hardware and software to implement the network functionality, such as overall network management and control, and routing of calls and data.

As noted above, certain services to be provided using the NR radio standards have strict reliability and latency targets. A general requirement for URLLC services (as defined in TR 38.913) is a reliability of 1x10 ^-5 for 32 bytes with a user plane latency of 1ms. In order to achieve targets such as this, rules for the allocation of transmission resources may be modified to allow control and data transmissions to overlap in time. For example, the Physical Uplink Control Channel (PUCCH) which carries Uplink Control Information (UCI) (such as HARQ feedback) and the Physical Uplink Shared Channel (PUSCH) which primarily transmits data from the logical shared channel may overlap. In other scenarios, a UE may be operating services of different priority levels. As packet arrival is not known a priori, a high priority packet coming after the low priority packet may lead to resource overlap situations. Such overlaps may also occur frequently when the base station has allocated periodic resources for UE transmission. Then the downlink transmissions requiring uplink control transmission or dynamic uplink control may result in overlap of resources with UE periodic resources. Simultaneous transmission of such channels on independent frequency resources may not be supported by UE hardware. Overlapping transmissions in this disclosure is meant to cover transmissions which have overlap of two transmissions in time domain. This time domain overlap covers the case where the two transmissions share at least one OFDM symbol. It also covers the case where the two transmissions fall within the same slot and UE is not capable of transmitting the two transmissions (e.g., due to hardware restrictions) within the slot. Overlapping resources has previously been supported by multiplexing PUCCH control information on PUSCH by puncturing UCI on PUSCH resources, or rate matching the PUSCH data. Such multiplexing increases the effective code rate and hence may lead to reduced reliability for both channels. The reduction in reliability may be significant if a large number of transport blocks (TBs) require acknowledgement or the configuration has a large HARQ codebook requiring transmission of a large number of bits.

Similarly, CodeBlock Group (CBG) feedback can lead to a large number of feedback bits to be transmitted.

Furthermore, transmissions each have a priority level associated with them, which may affect how to handle collisions. Evenly multiplexing two transmissions with very different priorities may lead to the unfair degradation of the higher priority transmission to allow transmission of a low priority signal. Where there is a difference in priority a fair transmission algorithm may elect to delay transmission of the lower priority signal to increase the reliability of the higher-priority transmission. This is particularly relevant where the higher priority transmission has a latency requirement that cannot be met if a retransmission is required. A particular case may arise where two conflicting transmissions have an equal priority requiring the UE to decide how to resolve the conflict without the benefit of an explicit indication of relative importance.

In a specific example, existing standards suggest that when multiplexing of configure grant (CG) -UCI and HARQ-ACK is not configured, a colliding CG-PUSCH should be skipped. Skipping a PUSCH transmission and trying to transmit it in a later occasion may be appropriate in some situations, for example if the PUSCH transmission is of low priority. However, if the PUSCH transmission has a low latency requirement, skipping PUSCH for a given occasion may result in violating the latency target and the packet will eventually be discarded. Methods for the multiplexing or prioritisation of PUCCH and PUSCH are set out below to address this and related difficulties.

This disclosure focuses on intra-UE overlapping control and data transmissions. The uplink data transmissions on PUSCH cover both dynamic grant (DG) based and configured grant (CG) based PUSCH transmissions. Thus, the methods proposed here are applicable to both types of PUSCH transmissions. For UE control transmission, the primary focus is on the control information comprising of HARQ feedback. This HARQ feedback will correspond to TB (s) that UE receives from other communicating entity, such as base station. Despite this disclosure keeping its focus on HARQ feedback, the principles set out below are applicable to general control transmissions, comprising one of HARQ feedback, scheduling request and channel state information etc. In addition, the scenarios of interest span when the system is operating over licensed band as well as when it is operating over shared unlicensed band. Unlicensed band operation brings some issues, primarily originating from the uncertainty of channel access on the unlicensed carrier. This results in making the colliding PUCCH and PUSCH problem worse compared to that of licensed band operation. Nevertheless, the methods and principles proposed in this disclosure are applicable to both licensed and unlicensed operation by providing principles which resolve the collisions/conflicts in a variety of scenarios.

Set out below are a set of methods for prioritisation of colliding transmissions based on the type and relative priority of the transmissions. A common principle is that data transmissions are prioritised over control transmissions carrying HARQ ACK/NACK (or other) control information. The base station assumes feedback missing as a result of transmitting PUSCH instead of PUCCH is a NACK and proceeds as if a NACK had been received (typically retransmission of the data assumed to have failed) . The prioritisation of data over control information improves the ability to meet latency targets for services.

Where colliding transmissions have equal priority the UE’s behaviour may depend on the priority. For example, for lower priority transmissions the signals may be multiplexed, accepting the potentially reduced reliability, whereas for higher priority transmissions the data transmission may be made and the colliding control transmission skipped. This helps meet the latency requirement for the high priority data transmission, and the base station can assume NACK for the unreceived control transmission. This may trigger an appropriate response from the base station to protect the transmission for which HARQ feedback was de-prioritized by UE. This response may be a fast re-transmission for the corresponding DL TB. In this way, the result is ensuring meeting the performance targets for both transmissions.

Transmissions may also be prioritised based on the control data content. For example, data may be prioritised over a HARQ NACK transmission (and the base station can assume NACK) , whereas a HARQ ACK may be prioritised over a data transmission.

As noted above, where CBG feedback is used the feedback transmission may be large. Where this feedback collides with a data transmission, particularly where the priorities are equal, the feedback may be changed to TB-based feedback.

These principles may be used in combination with each other or separately, as appropriate for each situation. The data transmissions may be either on Configured Grant (CG) or Dynamic Grant (DG) resources. Set out below are a selection of examples of these principles.

In a first example, shown in Figure 2, data and control (HARQ feedback) are scheduled (200) on PUSCH and PUCCH which overlap in time. At step 201 the UE skips transmission of the control transmission and at step 202 transmits the data on PUSCH. At step 203 the base station receives the PUSCH transmission, and detects the missing PUCCH transmission (which it was expecting due to the applicable on transmission of HARQ feedback) . At step 204 the base station assumes the HARQ feedback would have been a NACK and triggers the appropriate behaviour (for example retransmission) .

This method ensures the data transmission is made as scheduled such that latency requirements are met. According to this method, if the HARQ feedback is not transmitted in favour of the data the base station will assume that feedback would have been a NACK. If the actual feedback was going to be a NACK then the base station behaves correctly and in the same way as if the feedback had been transmitted. For the transport block whose HARQ feedback is missing, the re-transmission can also be decided at the base station as a function of transmission priority and remaining packet delay budget (PDB) . If there is sufficient time before expiry of PDB, the base station may trigger HARQ feedback. If PDB is about to expire, it may choose to schedule a re-transmission. In the same way, priority of the transmission can impact how the base station responds to the missing HARQ feedback. In addition, the data transmission is made without multiplexing it with the control information and so the reliability of that transmission is maintained. This approach also avoids a delay in data transmission, thus retaining latency performance. If the actual feedback was going to be an ACK the base station will make the wrong assumption and may attempt re-transmission of the data which is assumed to be lost. This re-transmission is not actually needed and so the efficiency of transmission resource utilisation is reduced, but the increased reliability of data transmission is likely to outweigh the reduced efficiency.

Figure 3 shows a further example of prioritization between data and control transmissions.

At step 300 a PUCCH transmission and a PUSCH transmission overlap in time, for example by at least one OFDM symbol duration. At step 301 the UE determines the relative priorities of the two transmissions. If the priorities are different, the UE proceeds to step 302 or 303 to transmit the transmission with the highest priority. The priority may be provided to the PHY layer based on an indication from the base station in an RRC/higher layer configuration, or dynamically in PHY layer signaling (for example in the relevant DCI) . If a priority is not specified the UE may assume normal or lowest priority. Control information such as HARQ feedback (FB) may be assumed to have their indicated priority which can be configured with the relevant HARQ codebook. In the absence of HARQ codebook priority or for other control information, the priority can be assumed to be the priority of the associated PDSCH.

If at step 301 the priorities are the same, the UE transmits (step 304) the data on PUSCH in preference to the control transmission on PUCCH. As will be apparent, the control transmission is only made if it has a higher priority than the data transmission.

If the control transmission is not made, as explained with reference to Figure 2, the base station assumes the HARQ feedback would have been a NACK and proceeds accordingly.

The flow chart of Figure 3 can be summarized as follows: -

PUSCH has higher or equal priority than PUCCH (HARQ FB) :

→ Transmit PUSCH and skip PUCCH (with HARQ FB) .

→ The base station assumes NACK for HARQ feedback when skipped in case of time overlap with PUSCH.

Otherwise:

→ Transmit PUCCH and skip PUSCH.

The method of Figure 3 ensures that the transmission with the highest priority is transmitted, and that the reliability of that transmission is not reduced by multiplexing control and data together. For cases where the data is transmitted in preference to the control information the advantages and effects are as described in relation to Figure 3. In particular, where the intended HARQ feedback was a NACK the actual behaviour is consistent with the behaviour if the control transmission was made, whereas if the HARQ feedback was to be an ACK an unnecessary transmission of the data may be performed leading to a reduction in transmission resource efficiency, but with the advantage of improved data transmission reliability. Though the base station can minimize un-necessary re-transmissions by analysing the transmission priority and the remaining PDB for the packet in question.

Where the control information is transmitted in preference to the data, that data can be re-scheduled to a later transmission opportunity (configured grant or dynamic grant as appropriate) . Re-transmission scheduling is straight-forward for the dynamic grant case by base station sending a new scheduling command. For the configured grant case, UE may transmit on the next periodic resource or may send a scheduling request with regards to the packet priority and PDB.

The process of Figure 3 addresses a potential problem where the actual number of HARQ feedback bits transmitted if they are multiplexed with a PUSCH may not be known. This may be particularly relevant for configured grant PUSCH. Since there is no multiplexing of control and data transmissions in the proposed scheme the base station either receives the full, original, transmission or nothing. Otherwise when multiplexed according to legacy procedures, a mis-alignment between the base station and UE about how many feedback bits are part of multiplexed control information may lead to a decoding error at the base station, making the multiplexed transmission worthless.

As will be apparent, the methods and processes discussed herein are applicable in general to PUSCH transmissions colliding with PUCCH. They are agnostic to whether resources are allocated as a dynamic grant or configured grant, and applicable to all types of PUSCH transmissions.

Figure 4 shows a further method of prioritizing transmissions. At step 400 a PUCCH and PUSCH are assigned to transmission resources which overlap in time, for example by at least one OFDM symbol duration. At step 401 the UE assesses the relative priority of the transmissions and if they are different proceeds to

steps

402 or 403 to transmit the highest priority transmission. If the two transmissions have the same priority the UE proceeds to step 404.

At step 404 the UE assesses the actual priority of the two transmissions. If the priority is low the UE multiplexes the data and control information and transmits the multiplexed data on PUSCH at step 405. If the priority is high at step 406 the UE transmits the data transmission on PUSCH in preference to the control information. As set out above, the base station assumes the not-transmitted HARQ feedback was a NACK message. An example with priorities can be with the physical layer priority indication. For URLLC services, the base station sets this indication as 1 (high priority) . For normal priority this indication is set to be 0 (normal or low priority) . A missing indication is also assumed to be 0. Then at step 401, the priorities of PUCCH and PUSCH are compared to decide whether to execute step 402 or step 403. If both PUCCH and PUSCH have same priority, step 404 compares what is the actual priority. In case of 0 (low priority) , UE multiplexes control and data according to step 405. In case of 1 (high priority) , UE transmits PUSCH as per step 404.

The method of Figure 4 ensures that low priority transmissions are made according to the scheduled timing, albeit with a potentially reduced reliability due to the multiplexing of control and data transmissions. However, for high priority transmissions this reduced reliability might lead to an inability to meet latency &QoS targets, hence the data is transmitted and not the control information. The base station will assume a NACK for the feedback. It may then decide to trigger feedback or retransmit the relevant data considering the priority levels and PDB, thus ensuring good quality transmission for both uplink and downlink data flows.

Figure 5 shows a further example of prioritisation where PUSCH transmission is for a dynamic grant or configured grant based PUSCH without CG-UCI. At step 500 PUCCH and PUSCH transmission are scheduled on resources which overlap in time, for example by at least one OFDM symbol. At step 501 the UE assesses the relative priority of the two transmissions, and if they are different proceeds to step 502 or 503 to transmit the highest priority transmission.

If the two transmissions have the same priority the UE proceeds to step 504 at which the nature of the PUCCH transmission is assessed. If the HARQ feedback in the control transmission is a NACK the UE proceeds to step 505 and transmits the PUSCH in preference to PUCCH. The base station assumes the expected HARQ feedback was a NACK message and proceeds accordingly, as discussed above.

If at step 504 the PUCCH transmission is an ACK message, at step 506 the UE transmits the PUCCH transmission in preference to the PUSCH. The advantage of this scheme is that the base station will not make any useless re-transmission for a missing HARQ feedback, as HARQ feedback is missed in step 505 only when it is NACK.

Figure 6 shows a modification of the method of Figure 5 for a system operating in unlicensed spectrum and configured to transmit configured-grant UCI with each configured grant PUSCH. This UCI may be termed CG-UCI. Steps which are the same as Figure 5 have the same reference numerals.

At step 600, if the HARQ feedback is ACK, the UE performs a further check whether CG-UCI and HARQ feedback multiplexing is enabled. If multiplexing is enabled the UE multiplexes the HARQ feedback with the CG-UCI at step 601, and transmits CG-PUSCH multiplexed with multiplexed CG-UCI and ACK. If multiplexing is not enabled PUCCH (with HARQ Feedback) is transmitted at step 602 and the CG-PUSCH (along with CG-UCI) is not transmitted.

If HARQ feedback is available for more than one TB, the HARQ feedback value (ACK or NACK) of the lastreceived TB prior to collision may be used at step 600. An alternative option is to combine the feedback of multiple TBs in a single Boolean value so as to facilitate the decisions of Figure 6. For example, for the case of single or multiple TBs with CBG based feedback, a single Boolean result can be obtained using a compression function over the available HARQ feedback bits.

In this method, if the feedback is a NACK the base station behaviour is as expected and there is no disadvantage from not transmitting the feedback. If the feedback is an ACK then the base station may schedule a retransmission leading to reduced transmission resource efficiency, but PUSCH is transmitted without degraded reliability.

Figure 7 shows a further method of prioritization, applicable where PUSCH and PUCCH transmissions overlap (Step 700) , for example by at least one OFDM symbol, and HARQ feedback is configured with CodeBlock Group (CBG) based feedback.

At step 701 the relative priorities are assessed and if they are different the higher priority transmission is made at

step

702 or 703, and the other transmission is skipped. If the two transmissions have the same priority the UE proceeds to step 704 and switches to TB-based HARQ feedback. At step 705 the UE transmits the PUCCH (with HARQ feedback) multiplexed with PUSCH. If PUSCH is a configured grant PUSCH transmission with CG-UCI, and HARQ feedback has the same priority, TB level HARQ feedback will be multiplexed with CG-UCI and transmitted along with PUSCH.

CBG-based feedback generally comprises more data than TB-based feedback and so switching to TB-based feedback reduces the feedback data to transmit. Hence the reduction in reliability of the PUSCH transmission due to multiplexing is reduced as less puncturing is required to accommodate the PUCCH transmission. The method also ensures TB-level feedback is transmitted without delay thus removing the need for a base station to make an assumption about the feedback due to a missing PUCCH transmission.

As noted above aspects of each of the examples may be used in different combinations than shown and described herein, which is particularly relevant for the change from CBG based HARQ feedback to TB based HARQ feedback which can be used in any of the above-described examples.

There are therefore provided various methods for resolving a conflict between scheduled data and control transmission. The conflict may be resolved by selecting the transmission to make based on the relative priorities of the transmissions, the type of transmission, or other relevant parameters of the two transmissions.

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) (RTM) 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’a nd 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 45 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 recognise 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. Also, 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 of prioritising between data and control transmissions from a UE to a base station where the transmissions have overlapping resources; the method comprising

at a UE scheduling data and control transmissions, wherein the transmission resources for each transmission overlap; and

at the UE selecting only one of the data and control transmission to transmit in the transmission resources;

wherein the step of selecting is performed based on a characteristic of the data and control transmissions.
A method according to claim 1, wherein the characteristic is the relative priority of the data and control transmissions.
A method according to claim 1 or claim 2, wherein the characteristic is the type of message.
A method according to any preceding claim, wherein the control transmission is a HARQ feedback transmission, and the UE selects the data transmission.
A method according to any preceding claim, wherein at the base station the missing

HARQ feedback transmission is assumed to be a NACK.
A method according to claim 5, wherein the base station schedules retransmission of the data which would have been acknowledged by the missing HARQ feedback transmission.
A method according to any preceding claim wherein the data transmission is selected for transmission based on the characteristic that the transmission carries data.
A method according to claim 2, wherein if the priorities are equal the UE performs the step of selecting based on the absolute priority of the transmissions.
A method according to claim 8, wherein if the absolute priority is low the UE selects both transmissions and multiplexes the control transmission with the data transmission.
A method according to claim 9, wherein the UE switches to TB-based feedback for the multiplexed control transmission.
A method according to claim 8, wherein if the absolute priority is high the UE selects the data transmission.
A method according to any preceding claim, wherein the characteristic is the type of HARQ feedback message.
A method according to claim 12, wherein if the control transmission is a NACK message the data transmission is transmitted, and if the control transmission is an ACK the control transmission is transmitted.
A UE configured to perform the method of any of claims 1 to 13.