GB2579793A - Uplink pre-emption indication - Google Patents

Abstract

When a UE is in good coverage, a base station transmits a pre-emption indication only if the UE is to be interrupted. A UE in good coverage that does not receive a pre-emption indication assumes no interruption and so continues its uplink transmission. When a UE is in bad coverage, the base station transmits a positive pre-emption indication if the UE is to be interrupted and a negative pre-emption indication if the UE is not to be interrupted. The UE in bad coverage terminates its uplink transmission if no pre-emption indication is received. The UE only monitors for a pre-emption indication at an indicated schedule if it has uplink resources allocated for the period to which the indicated schedule relates. The pre-emption indication comprises an indication of which frequencies and/or symbols will be pre-empted using a resource indication value (RIV) format.

Description

Uplink Pre-emption Indication

Technical Field

[1] The following disclosure relates to pre-emption in cellular communication networks, and in particular to the indication of pre-emption for uplink transmissions.

Background

[2] 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 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.

[3] 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.

[4] 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.

[5] 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.

[6] In contrast to URLLC and mMTC services, mobile broadband services such as eMBB (enhanced Mobile Broad Band) aim to provide high capacity data services to UEs, but with less strict latency and reliability requirements. eMBB services can consume large amounts of transmission resources to provide the required service which has consequences for the provision of other services, particularly those with stringent latency requirements.

[7] Since transmissions by URLLC and mMTC services can be sporadic it is inefficient to reserve transmission resources in case a transmission occurs. Instead a system of pre-emption may be utilised. Resources may be allocated to eMBB services, but a facility is provided to interrupt (pre-empt) transmission on the allocated resources to enable transmission of data for URLLC/mMTC type communications.

[8] The RAN has responsibility for scheduling transmission resources and thus has control of the pre-emption process. The RAN can thus effectively manage pre-emption in the downlink direction since it is responsible for scheduling and transmission. However, the uplink is more challenging because resource allocation, and changes thereto, need to be communicated to each UE such that they can transmit accordingly.

[9] There is therefore a requirement for a robust and efficient pre-emption system for uplink transmissions.

Summary

[10] 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.

[11] There is provided a method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the steps of at a base station determining if a UE is in bad coverage, and; if the UE is in bad coverage transmitting an uplink pre-emption indication message to the UE indicating whether resources allocated to the UE will be pre-empted or will not be pre-empted; if the UE is not in bad coverage and resources allocated to the UE will be preempted transmitting an uplink pre-emption indication message to the UE indicating that the allocated resources will be pre-empted; and if the UE is not in bad coverage and resources allocated to the UE will not be pre-empted skipping transmission of an uplink pre-emption indication message.

[12] A UE may be determined as being in bad coverage if a DCI message to the UE scheduling the resources was transmitted at an Aggregation Level equal to or above a predefined threshold.

[13] The threshold may be Aggregation Level 8 or Aggregation Level 16.

[14] A UE may be determined as being in bad coverage if the MCS value for the DCI is less than a predetermined value.

[15] The uplink pre-emption indication message may be transmitted as a PDCCH message.

[16] The PDCCH message may be a group-common message.

[17] The uplink pre-emption indication may comprise an indication of the resources that will be pre-empted.

[18] The uplink pre-emption indication may comprise an indication of the frequencies which will be pre-empted.

[19] The frequency information may be provided in a Resource Indication Value (RIV) format.

[20] The uplink pre-emption indication may comprise an indication of the symbols which will be pre-empted.

[21] The symbol information may be provided in a Resource Indication Value (RIV) format.

[22] The uplink pre-emption indication may comprise a configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.

[23] The uplink pre-emption may relate to pre-emption by more than one other UE.

[24] The uplink pre-emption may indicate pre-empted resources allocated to more than UE.

[25] There is also provided a method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the steps of at a UE receiving an indication of scheduling of at least one uplink pre-emption indication; if the UE has uplink resources allocated for the period to which the at least one uplink pre-emption indication relates which may be pre-empted, monitoring for an uplink pre-emption indication at the indicated schedule; if the UE receives an uplink pre-emption indication, acting in accordance with the indication to continue transmissions or terminate transmissions from an indicated symbol; if the UE does not receive an uplink pre-emption indication, determining if the UE is in bad coverage; and if the UE is in bad coverage terminating uplink transmission in the period to the which the uplink pre-emption indication would have related; if the UE is not in bad coverage continuing uplink transmission.

[26] A UE may be determined as being in bad coverage if a DCI message to the UE scheduling the resources was transmitted at an Aggregation Level equal to or above a threshold.

[27] The threshold may be Aggregation Level 8 or Aggregation Level 16.A UE may be determined as being in bad coverage if the MCS value for the DCI is less than a predetermined value.

[28] The uplink pre-emption indication message may be received as a PDCCH message.

[29] The PDCCH message may be a group-common message.

[30] The uplink pre-emption indication may comprise an indication of the resources that will be pre-empted.

[31] The UE only acts upon the uplink pre-emption indication if the indicated resources overlap with uplink resources allocated to the UE.

[32] The uplink pre-emption indication may comprise an indication of the frequencies which will be pre-empted.

[33] The frequency information may be provided in a Resource Indication Value (RIV) format.

[34] The uplink pre-emption indication may comprise an indication of the symbols which will be pre-empted.

[35] The symbol information may be provided in a Resource Indication Value (RIV) format.

[36] The uplink pre-emption indication may comprise a= configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.

[37] The uplink pre-emption indication may relate to pre-emption by more than one other UE.

[38] The uplink pre-emption may indicate pre-empted resources allocated to more than UE.

[39] There is also provided a base station configured to perform the methods described herein.

[40] There is also provided a mobile device configured to perform the methods described herein.

[41] There is also provided a method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the step of at a base station transmitting an uplink pre-emption indication message to a UE indicating whether resources allocated to the UE will be pre-empted; wherein the uplink pre-emption indication message comprises an indication of the resources that will be pre-empted.

[42] The uplink pre-emption indication may comprise an indication of the frequencies which will be pre-empted.

[43] The frequency information may be provided in a Resource Indication Value (RIV) format.

[44] The uplink pre-emption indication comprises an indication of the symbols which will be pre-empted.

[45] The symbol information may be provided in a Resource Indication Value (RIV) format.

[46] The uplink pre-emption indication may comprise a configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.

[47] The uplink pre-emption may relate to pre-emption by more than one other UE.

[48] The uplink pre-emption may indicate pre-empted resources allocated to more than UE.

[49] 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

[50] 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.

[51] Figure 1 shows a schematic diagram of parts of a cellular network; [52] Figure 2 shows an example of pre-emption signals; [53] Figures 3 and 4 show an example process for the transmission of pre-emption signals; [54] Figure 5 shows a table of RIV values; [55] Figure 6 shows an example pre-emption indication; [56] Figure 7 shows examples of pre-empted resources; and [57] Figure 8 shows an example of pre-emption signalling. Detailed description of the preferred embodiments [58] 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.

[59] 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.

[60] 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.

[61] In the following disclosure the term "eMBB UE" will be used to describe a UE utilising an eMBB-type service (a service with an emphasis on capacity rather than latency), and "URLLC UE" will be used to describe a UE utilising a URLLC-type service (a service with an emphasis on latency rather than capacity). This does not suggest the UEs are different and only able to operate with those services, but only that they are using those services at the time under discussion.

[62] Figure 2 shows a system of UpLink Pre-emption Indication (UL PI). The RAN transmits a DCI 200 to an eMBB UE to allocate resources 201 for an uplink transmission in the subsequent slot. That uplink transmission is in the form of PUSCH, which is transmitted across a range of frequency and time resources. In this example a subset of frequency resources for the duration of the slot are allocated.

[63] Subsequent to the transmission of the DCI 200, a URLLC UE transmits a Scheduling Request (SR) 202. The RAN receives the request, allocates resources 203 in the subsequent slot, and transmits a URLLC DCI 204 to the UE. The allocated resources conflict with those allocated to the eMBB UE and those resources must therefore be pre-empted. The RAN thus also transmits a pre-emption indication 205 informing the eMBB UE of the resources to which it no longer has access. The eMBB UE may choose to continue its transmissions around the indicated resources or stop transmissions for the remainder of the allocated resources.

[64] Due to the latency requirements of URLLC transmissions URLLC DCI 204 and UL PI 205 may need to be transmitted at the same time as shown in Figure 2. The URLLC DCI 204 needs to be transmitted with very high reliability because the URLLC transmission is dependent on its successful receipt. A failed transmission is likely to lead to increased latency and a failure to meet a specific standard. There may be insufficient transmission resources available for both the URLLC DCI 204 and UL PI 205 to be transmitted at the required time and with the required reliability, particularly if the UE has been allocated a narrow BWP (BandWidth Part). A BWP is a bandwidth which is smaller than its most capable bandwidth and was introduced to save UE power as the UE only needs to process resources within the BWP. For a UE with limited power, the gNB may configure it a narrow BWP, e.g., 1MHz or 5MHz, so it doesn't need to monitor the whole bandwidth such as possibly 40MHz or 80MHz. Within the narrow BWP, there may not be enough resources to ensure a high reliability for either DCI 204 or UL PI 205.

[65] The UL PI may thus have to utilise a reduced reliability target (e.g. 10-3 or 104). However, a lost UL PI will lead to the eMBB transmission continuing and possibly corrupting the conflicting URLLC transmission.

[66] The above example utilises a UL PI signal to indicate the eMBB UL transmission should be suspended (termed U-INT) which requires a high reliability. An alternative is for a UL PI signal to provide an indication that eMBB UL transmission should continue (U-CON). That is, the RAN transmits a PI signal to indicate a UE can transmit in the allocated resources. This requires a lower reliability (since a failed signal results in no transmission and hence no potential conflict with a URLLC transmission) but increases control overhead as the signal must be transmitted at every UL PI transmission opportunity.

[67] Figure 3 shows an example of a U-CON PI process. At step 300 the RAN ascertains whether a UL transmission is to be pre-empted. In both cases a UL PI is transmitted from the RAN to relevant UEs. If there is no pre-emption, at step 301 the UL PI includes a dedicated value indicated that. If there is pre-emption, at step 302 the PI payload indicates the resources that are pre-empted. At steps 303 a CRC may be added.

[68] The UL PI may be transmitted to UEs in any convenient manner. For example, as shown at step 304, the UL PI may be transmitted as a group common PDCCH transmission. This example allows one message to address multiple UEs, thereby reducing control signalling overhead. The UL PI indicates the resources now allocated to a URLLC UE and so the same information is applicable to all eMBB UEs which may need to interrupt transmissions.

[69] eMBB UEs receiving 305 the UL PI act 306 in accordance with its content. If the message indicates no pre-emption the UE continues with its scheduled transmissions, and if the message indicates pre-emption the UE behaves appropriately (for example, suspends transmissions on the relevant resources) such that the indicated resources are not utilised.

[70] If an eMBB UE does not receive 307 an expected UL PI the scheduled transmissions are cancelled 308 to avoid any potential conflict with a URLLC transmission that may have been indicated by the lost UL Pl. This ensures reliability of the URLLC transmission but results in wasted resources if the lost UL PI indicated there was no pre-emption as the eMBB transmission was cancelled unnecessarily.

[71] In an example configuration there may be three UL Pls planned for each slot (every 5 OFDM symbols), each relating to the subsequent 4 or 5 OFDM symbols. The requirement to transmit a UL PI in every opportunity thus creates significant signalling overhead.

[72] Failure to receive a UL PI is only likely to occur when a UE has poor signal quality. When a UE has a good signal the reliability is high enough that the U-INT system can be utilised in which non-reception is an indication to continue transmission. This avoids the need to transmit a UL PI at every opportunity. However, this approach may not be suitable in poor signal situations as the reliability of the UL PI is insufficient to give the required URLLC reliability.

[73] Figure 4 shows a dynamic method for UL PI which aims to balance reliability and control overhead considerations. At step 400 the RAN checks if eMBB transmissions are to be preempted, and if they are a UL PI message is formed at 401. As set out above a CRC may be added 402 and the message may be transmitted 403 as a group common PDCCH message.

[74] Returning to step 400, if there is no pre-emption, the RAN assesses 406 whether relevant UEs are in good coverage. The assessment of coverage may be made in any appropriate way. For example, the MCS (indicated in DCI for UL grant) may utilised as an indication of channel quality. An MCS less than #N may indicate a poor signal, and above #N a good signal. #N may be pre-configured, static, semi-static or dynamic. The MCS tested is for PUSCH which is a UL channel, whereas the UL PI is to be sent in DL. Utilising MCS thus relies on UL and DL channels being of similar quality.

[75] Alternatively the Aggregation Level (AL) of the DCI used for indicating UL grant may be utilised. For example, AL 16 may indicate a bad signal, with other values indicated a good signal.

[76] If the relevant UE is in good coverage no UL PI is transmitted at 407. If the UE is not in good coverage a UL PI is prepared at 408 including an indication that there is no pre-emption. The message is prepared for sending in the appropriate way, for example with an optional CRC added and using a group common PDCCH message. Alternatively a sequence-based encoder may be utilised. Such an encoder may also be used instead of some or all of the PDCCH encoders described in relation to Figure 3 and the other encoder of Figure 4. Sequence-based encoders may have better performance for very small payloads (<= 11 bits).

[77] The right hand side of Figure 4 shows an example of the behaviour of UEs in conjunction with the RAN behaviour shown on the left side of Figure 4 and described hereinbefore. The UE behaviour may be applied in conjunction with, or in the absence of, the techniques described for the RAN.

[78] If a UE successfully receives a UL PI at 404 it acts 405 as indicated to continue or suspend its transmissions.

[79] If no UL PI is received 408 at an expected location the UE determines 409 if it is in good coverage. The same principles and methods described above maybe applied for this determination. If the UE is in good coverage the UE continues with scheduled transmissions at 410, but if the UE is not in good coverage then transmissions are suspended 411 for the period that would have been covered by the expected UL Pl.

[80] The process described with reference to Figure 4 aims to reduce the number of UL PI transmissions that must be made, while retaining appropriate reliability. This is achieved by the distinct processes dependent on whether the UE is in good or bad coverage. When the UE is in good coverage a U-I NT type signalling system can be used in which a signal is only sent if the UE is to be interrupted. This achieves acceptable reliability because the channel provides sufficient reliability for the delivery of the UL PI and it is reasonable to assume that lack of a UL PI at the UE is due to no transmission rather than a lost message. In contrast when the UE is in bad coverage a U-CON type system is used in which the UE interrupts transmissions unless a positive indication that there is no pre-emption is received. In summary, a UL PI is always transmitted to UEs in bad coverage, but only transmitted to UEs in good coverage if there is preemption.

[81] Generally few UEs have a sufficiently bad signal quality to require always transmitting a UL Pl. Furthermore, as noted above, there is only a need to transmit a UL PI if a UE has a PUSCH in the same period. Similarly, UEs will only monitor for a UL PI if they have a PUSCH scheduled in the relevant period. Therefore, it is only the minority of UEs in bad coverage, with a scheduled PUSCH, which require a UL PI to always be transmitted. The disclosed method therefore provides a significant reduction in control signalling overhead.

[82] A simple indication in the UL PI that scheduled resources have been pre-empted can be used to avoid a conflict. Upon receipt of the indication the eMBB UE cancels all transmissions in the relevant period and the URLLC UE is free to transmit. However, this is inefficient as it is unlikely the URLLC UE will use all resources in the period, and hence resource will be left unused. The efficiency can be improved if the UL PI includes details of the specific resources that have been pre-empted. The UE can then cancel the relevant parts of the transmissions and use other unaffected resources to continue transmissions. The resource indication may be provided in one or both of frequency and time. If only one is indicated with all resources in the other domain assumed to be interrupted, or if both are provided, the specific resources can be interrupted with no unused resources. The resource indication may be provided in any suitable format for time and frequency, independently or in combination.

[83] Section 6.1.2.2.2 of TS 38.214 defines a Resource Indication Value (RIV) which may be used to indicate uplink resource allocations. A comparable system may be utilised to indicate pre-empted resources. Figure 5 shows a full set of RIVs, assuming a bandwidth part size of 20. The maximum value is 209 so each RIV needs 8 bits. However, those 8 bits can represent numbers up to 255 and so any value from 210 to 255 can be used to indicate no pre-emption.

[84] In general the number of bits needs to be no les than log2((N+")*N/2 (the smallest integer greater than the result), where N is the number of resources to be allocated in the given units (20 in the example above).

[85] When used for UL PI both frequency and time domain resources can be allocated using a RIV format, for example RIVt and RIVf. Resources covered by both RIVt and RIVf are indicated as pre-empted. In the example above, in which each UL PI covers up to five symbols, 4 bits are needed for RIVt.

[86] It is desirable to minimise the size of the UL PI messages, but also to ensure accurate indication of resources to avoid waste. In the frequency domain the size of the UL PI may be 7 reduced by indicating a common BWP for all URLLC UEs with scheduled resources, rather than a specific BWP for each UE. A common BWP is a continuous bandwidth which contains all relevant URLLC UEs' BWPs so that when the group common PDCCH is used for UL PI, the indication can be interpreted in the same BWP. A relevant URLLC UE may transmit with resources pre-empted from an eMBB UE. This common BWP can be indicated in the system information or separately configured. Also, RB can be replaced with RBG which is a group of RBs and the number of RBs per RBG can be indicated in the system information or separately configured. This reduces the number of bits required for the RIV as per the above-shown equation. However, a larger RBG gives a bigger granularity which may prevent indicating the pre-empted area precisely and thus impact eMBB performance due to unnecessary cancelation.

[87] One UL PI can include more than one cells' PI and each cell's PI can include multiple and/or combinations of separate pre-emptions. A summary can be found in Figure 6 and n, m are configurable. Note that CRC is optional, and depending on the payload size of the UL PI, CRC may be needed when the payload size is over a threshold.

[88] Furthermore, the UL PI size can be reduced by defining a single area covering multiple UEs as shown in Figure 7. In Figure 7a two eMBB UEs are scheduled with resources 700, 701 which are multiplexed in frequency. Two pre-emptions 702, 703 are indicated and each preemption has one corresponding combination of RIV, and RIVr in the PI field. Each eMBB UE will confirm the resources indicated in RIVf overlap with its resources, and if so cancel its transmissions from the first symbol indicated by RIV1. However, four RIV values are required.

[89] In Figure 7b a single zone 704 is defined covering both pre-emptions 702, 703 and which zone can be specified with two RIV values hence reducing control signalling. Both UEs will cancel their transmissions from the start of zone 704 which avoids conflict, but wastes resources as transmissions with no conflict (Symbol 1 for UE1) are cancelled. There is thus a trade-off between control signalling size and efficient use of resources.

[90] Assuming an eMBB UE suspends all transmissions in symbols which are pre-empted (i.e. it does not attempt use frequencies in a pre-empted symbol which are not used by the URLLC UE), the zone 705 shown in Figure 7c will achieve the same effect as zone 804 and additionally assuming the eMBB UE does not re-start transmissions after the pre-empted symbols, the 706 shown in Figures 7d will also achieve the same effect as zone 804 and both cause transmissions to be suspended from symbol 1.

[91] Utilising zones as shown in Figure 7 allows a larger RBG to be defined, and hence also reduced the size of each RIV, as well as reducing the number of RIVs required.

[92] As set out above there is provided a process for indicating pre-emption on uplink resources, and a system for indicating the resources that have been pre-empted. Each part may be used alone or in combination. Set out below is an example in which both techniques are utilised in combination.

[93] A RAN (in particular a base station/gNB) selects a common bandwidth part and indicates it to the relevant eMBB UEs (whose resources may be pre-empted by a URLLC UE) in either UEspecific or broadcast messages. The common bandwidth part needs to contain all BWPs of connected URLLC UEs in the cell and when new URLLC UEs are connected or old URLLC UEs are disconnected, the common BWP may need to be updated.

[94] CORESETs for UL PI are also configured for the eMBB UEs to monitor. eMBB UEs with a PUSCH scheduled in a relevant period monitor for an UL PI in the indicated CORESET (there is no need for an eMBB UE without a scheduled PUSCH to monitor).

[95] If no UL PI is detected by a UE in the relevant CORESET and the eMBB UE was scheduled by a DCI with AL 16 for the period covered by the expected UL PI, the scheduled transmission is cancelled. If another AL was used (i.e. the UE is in good coverage) the PUSCH transmission is made.

[96] If a UL PI is detected the action is determined by the content of the message:- - If it indicates no pre-emption in the UE's cell, the eMBB UE continues the scheduled transmission in the cell; - If it indicates a pre-emption in the UE's cell, but the pre-empted resources obtained from the RIV do not overlap with the UE's scheduled resources, the eMBB UE continue the scheduled transmission in the cell; - If it indicates a pre-emption in the UE's cell, and the pre-empted resources obtained from the RIV overlap with the eMBB UE's scheduled resources, the eMBB UE cancels the scheduled transmission. The transmission may be cancelled from the start of the relevant period or from the start symbol indicated in the RIV. The UE may or may not resume its transmission after the end of the pre-emption period indicated in the RIV.

[97] Figure 8 shows a further example of pre-emption applied to three UEs in a cell.

[98] eMBB UEs #1, #2, and #3 are allocated PUSCH transmission resources 800, 801, 802. UEs #1 and #2 are in good coverage, while UE #3 is in bad coverage. The coverage quality may be assessed from the AL of the DCI used to schedule the PUSCH transmissions. UL Pls are transmitted on DL as shown at 803, with each PI relating to a mini-slot of four symbols. A common BWP is configured for all UEs to interpret the UL Pl.

[99] UEs #1 & #2 are scheduled in mini-slot #0 and so will monitor PI #0. UE #3 is not scheduled in that mini-slot and so does not monitor that Pl. There is no pre-emption in mini-slot #0 and no UEs with bad coverage so the RAN can skip transmission of UL PI #0. As UEs #1 and #2 are in good coverage they will continue transmission in the absence of receiving the UL Pl.

[100] UEs #1 and #3 will monitor PI #1 as they are scheduled in mini-slot #1. A pre-emption 804 has been scheduled for symbols 6 & 7 the RAN transmits PI #1 indicating the pre-empted resources. As set out above the resources may be indicated by RIVt and RIV,. Upon receipt of the UL PI UE #1 can identify that the pre-empted resources overlap with its scheduled transmission and so cancels its transmissions from symbol 6. UE #1 may re-commence transmission from symbol 8 or not.

[101] If UE #3 receives UL PI #1 it can identify that the pre-empted resources do not overlap with its scheduled transmission and so can continue. However, if UE #3 does not receive UL PI #1 it will suspend transmissions because it is in bad coverage. This suspension will start at the first scheduled symbol, 4, because the UE does not know where the pre-emption may occur.

[102] UEs #1 and #3 monitor UL PI #2 because they are both scheduled. There is no preemption but because UE #3 is in bad coverage the RAN transmits UL PI #2 with a "no preemption" indication. UEs #1 and #3 will continue their transmission if they receive the UL PI #2. UE #1 is in good coverage and so will continue transmission even if it does not receive UL PI #2, but UE #3 will stop transmission at symbol 8 (the first symbol referenced by UL PI #2) if it does not receive UL PI #2 because it is in bad coverage.

[103] The methods and techniques described above thus allow effective management of UL pre-emption by utilising a protocol appropriate to the channel reliability.

[104] 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.

[105] 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.

[106] 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.

[107] 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 RVV), 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.

[108] 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.

[109] 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.

[110] 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 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.

[111] 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.

[112] 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.

[113] 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.

[114] 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.

[115] 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.

[116] 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.

[117] 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.

[118] 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 (39)

1. Claims 1. A method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the steps of at a base station determining if a UE is in bad coverage, and; if the UE is in bad coverage transmitting an uplink pre-emption indication message to the UE indicating whether resources allocated to the UE will be preempted or will not be pre-empted; if the UE is not in bad coverage and resources allocated to the UE will be preempted transmitting an uplink pre-emption indication message to the UE indicating that the allocated resources will be pre-empted; and if the UE is not in bad coverage and resources allocated to the UE will not be pre-empted skipping transmission of an uplink pre-emption indication message.
2. 2. A method according to claim 1, wherein a UE is determined as being in bad coverage if a DCI message to the UE scheduling the resources was transmitted at an Aggregation Level equal to or above a predefined threshold.
3. 3. A method according to claim 2, wherein the threshold is Aggregation Level 8 or Aggregation Level 16.
4. 4. A method according to claim 1, wherein a UE is determined as being in bad coverage if the MCS value for the DCI is less than a predetermined value.
5. 5. A method according to claim 1, wherein the uplink pre-emption indication message is transmitted as a PDCCH message.
6. 6. A method according to claim 5, wherein the PDCCH message is a group-common message.
7. 7. A method according to any preceding claim, wherein the uplink pre-emption indication comprises an indication of the resources that will be pre-empted.
8. 8. A method according to any preceding claim, wherein the uplink pre-emption indication comprises an indication of the frequencies which will be pre-empted.
9. 9. A method according to claim 8, wherein the frequency information is provided in a Resource Indication Value (RIV) format.
10. 10. A method according to any preceding claim, wherein the uplink pre-emption indication comprises an indication of the symbols which will be pre-empted.
11. 11. A method according to claim 10, wherein the symbol information is provided in a Resource Indication Value (RIV) format.
12. 12. A method according to any preceding claim wherein the uplink pre-emption indication comprises a configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.
13. 13. A method according to any preceding claim, wherein the uplink pre-emption relates to preemption by more than one other UE.
14. 14. A method according to any preceding claim wherein the uplink pre-emption indicates preempted resources allocated to more than UE.
15. 15. A method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the steps of at a UE receiving an indication of scheduling of at least one uplink pre-emption indication; if the UE has uplink resources allocated for the period to which the at least one uplink pre-emption indication relates which may be pre-empted, monitoring for an uplink pre-emption indication at the indicated schedule; if the UE receives an uplink pre-emption indication, acting in accordance with the indication to continue transmissions or terminate transmissions from an indicated symbol; if the UE does not receive an uplink pre-emption indication, determining if the UE is in bad coverage; and if the UE is in bad coverage terminating uplink transmission in the period to the which the uplink pre-emption indication would have related; if the UE is not in bad coverage continuing uplink transmission.
16. 16. A method according to claim 15, wherein a UE is determined as being in bad coverage if a DCI message to the UE scheduling the resources was transmitted at an Aggregation Level equal to or above a threshold.
17. 17. A method according to claim 16, wherein the threshold is Aggregation Level 8 or Aggregation Level 16.
18. 18. A method according to claim 15, wherein a UE is determined as being in bad coverage if the MCS value for the DCI is less than a predetermined value.
19. 19. A method according to claim 15, wherein the uplink pre-emption indication message is received as a PDCCH message.
20. 20. A method according to claim 19, wherein the PDCCH message is a group-common message.
21. 21. A method according to any of claims 15 to 20, wherein the uplink pre-emption indication comprises an indication of the resources that will be pre-empted.
22. 22. A method according to claim 21, wherein the UE only acts upon the uplink pre-emption indication if the indicated resources overlap with uplink resources allocated to the UE.
23. 23. A method according to any of claims 15 to 20, wherein the uplink pre-emption indication comprises an indication of the frequencies which will be pre-empted.
24. 24. A method according to claim 23, wherein the frequency information is provided in a Resource Indication Value (RIV) format.
25. 25. A method according to any of claims 15 to 20, wherein the uplink pre-emption indication comprises an indication of the symbols which will be pre-empted.
26. 26. A method according to claim 25, wherein the symbol information is provided in a Resource Indication Value (RIV) format.
27. 27. A method according to any of claims 15 to 24 wherein the uplink pre-emption indication comprises a= configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.
28. 28. A method according to any of claims 15 to 27, wherein the uplink pre-emption indication relates to pre-emption by more than one other UE.
29. 29. A method according to any of claims 15 to 28 wherein the uplink pre-emption indicates pre-empted resources allocated to more than UE.
30. 30. A base station configured to perform the method of any of claims 1 to 14.
31. 31. A mobile device configured to perform the method of any of claims 14 to 29.
32. 32 A method of pre-emption indication for uplink transmissions from UEs to a base station, the method comprising the step of at a base station transmitting an uplink pre-emption indication message to a UE indicating whether resources allocated to the UE will be pre-empted; wherein the uplink pre-emption indication message comprises an indication of the resources that will be pre-empted.
33. 33. A method according to claim 32, wherein the uplink pre-emption indication comprises an indication of the frequencies which will be pre-empted.
34. 34. A method according to claim 33, wherein the frequency information is provided in a Resource Indication Value (RIV) format.
35. 35. A method according to any of claims 32 to 34, wherein the uplink pre-emption indication comprises an indication of the symbols which will be pre-empted.
36. 36. A method according to claim 35, wherein the symbol information is provided in a Resource Indication Value (RIV) format.
37. 37. A method according to any of claims 32 to 36 wherein the uplink pre-emption indication comprises a configuration of a common BandWidth Part (BWP) which contains all BWPs for signals pre-empting the allocated resources.
38. 38. A method according to any of claims 32 to 37, wherein the uplink pre-emption relates to pre-emption by more than one other UE.
39. 39. A method according to any of claims 32 to 38 wherein the uplink pre-emption indicates pre-empted resources allocated to more than UE.