Hybrid automatic request (HARQ) feedback

Abstract

A user equipment comprises components for: receiving, from a network node, an indication to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and disabling hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure according to the received indication.

Description

Technical Field

[0001] Examples of the present disclosure relate to hybrid automatic request (HARQ) feedback. Some relate to hybrid automatic request (HARQ) feedback for confirming correct reception of a downlink content resolution message (Msg4) in a contention-based random access (CBRA) procedure. Background Art

[0002] Hybrid Automatic Request (HARQ) feedback is used to confirm the correct reception of the downlink content resolution message (Msg4) in the contention-based random access (CBRA) procedure. Summary of the invention

[0003] According to various but not necessarily all examples, there is provided a user equipment comprising means for:

[0004] receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and

[0005] Means for disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure based on the received indication.

[0006] In some but not necessarily all examples, the indication specifies disabling, or provides conditions for the UE to determine disabling.

[0007] In some but not necessarily all examples, the indication includes received broadcast system information.

[0008] In some but not necessarily all examples, the broadcast system information defines one or more coverage enhancement levels, wherein at least one coverage enhancement level is associated with disabling.

[0009] In some but not necessarily all examples, the broadcast system information defines one or more thresholds for evaluating downlink signals at user equipment.

[0010] In some but not necessarily all examples, the indication is a modified downlink random access response in a contention-based random access procedure.

[0011] In some but not necessarily all examples, the indication is downlink control information including a modified HARQ-ACK resources field.

[0012] In some but not necessarily all examples, modification of the downlink control information field is indicated in the broadcast system information, or is predefined in the specification.

[0013] In some but not necessarily all examples, the user equipment includes means for disabling hybrid automatic request (HARQ) feedback for downlink data messages following the contention resolution message in accordance with the received indication.

[0014] In some but not necessarily all examples, the user equipment includes components for:

[0015] A disabled capability is indicated to a network node, the disabled being a disabled hybrid automatic request (HARQ) feedback at a user equipment for at least a downlink contention resolution message in a contention based random access procedure.

[0016] In some but not necessarily all examples, the user equipment comprises means for indicating the disabled capability to the network node using an uplink message of a contention based random access (CBRA) procedure.

[0017] In some but not necessarily all examples, means for indicating to a network a disabled capability at a user equipment for hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention based random access (CBRA) procedure includes means for implicitly indicating the capability by constraining a detectable feature of a random access request in a contention based random access procedure.

[0018] In some but not necessarily all examples, means for indicating to a network a disabled capability at a user equipment for hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention based random access (CBRA) procedure includes means for implicitly indicating the capability by selecting between different configurations for a random access request in a contention based random access procedure, wherein a first set of configurations indicates capability and a second set of configurations indicates a lack of capability.

[0019] In some but not necessarily all examples, the means for implicitly indicating capability includes: means for selecting a preamble for a random access request from a first predefined subset to use to indicate a first capability, and means for selecting a preamble for a random access request from a second predefined subset to indicate a second capability, and / or the means for implicitly indicating capability includes: means for selecting a subcarrier for a random access request from the first predefined subset to use to indicate the first capability, and means for selecting a subcarrier for a random access request from the second predefined subset to indicate the second capability, and / or the means for implicitly indicating capability includes: means for selecting a time domain resource for a random access request from the first predefined subset to use to indicate the first capability, and means for selecting a time domain resource for a random access request from the second predefined subset to indicate the second capability.

[0020] In some but not necessarily all examples, means for indicating to a network a disabled capability at a user equipment for hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention based random access (CBRA) procedure includes means for explicitly indicating the capability by adapting a scheduled UL transmission in a contention based random access (CBRA) procedure.

[0021] In some but not necessarily all examples, the user equipment includes a component for performing a contention-based random access (CBRA) procedure, the CBRA procedure comprising: sending a random access request; receiving a random access response; sending a scheduled UL transmission; receiving a contention resolution message; and the user equipment includes a component for determining from downlink control information that the next contention resolution message sent is the last contention resolution message sent and there is no subsequent retransmission of the contention resolution message.

[0022] In some but not necessarily all examples, the user equipment includes means for stopping the contention resolution timer based on determining from the downlink control information that the next transmitted contention resolution message is the last transmitted contention resolution message.

[0023] According to various but not necessarily all examples, a method is provided, the method comprising: receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure; and disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in the contention-based random access procedure based on the received indication.

[0024] According to various but not necessarily all examples, a computer program is provided, the computer program comprising instructions that, when executed on an apparatus, enable the apparatus to control: receiving an indication to disable hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure; and disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure based on the received indication.

[0025] According to various but not necessarily all examples, there is provided a network node comprising means for:

[0026] Disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure is indicated to at least the user equipment.

[0027] In some but not necessarily all examples, means for indicating disabling of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure at a user equipment includes means for indicating disabling or providing conditions for the UE to determine disabling.

[0028] In some but not necessarily all examples, means for indicating disabling at a user equipment of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure includes means for broadcasting system information to indicate the disabling.

[0029] In some but not necessarily all examples, the system information is included in a broadcast system information block.

[0030] In some but not necessarily all examples, the system information defines one or more coverage enhancement levels, wherein at least one coverage enhancement level is associated with disabling at a user equipment of hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure.

[0031] In some but not necessarily all examples, the system information defines one or more thresholds for assessing signal quality at the user equipment.

[0032] In some but not necessarily all examples, means for indicating disabling of hybrid automatic request (HARQ) feedback for a downlink contention resolution message in a contention-based random access procedure at a user equipment includes means for modifying a downlink random access response in a contention-based random access procedure to indicate disabling.

[0033] In some but not necessarily all examples, means for indicating disabling at a user equipment of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure includes means for indicating the disabling using downlink control information.

[0034] In some but not necessarily all examples, the network node includes means for modifying a HARQ-ACK resource field in the downlink control information to indicate disabling.

[0035] In some but not necessarily all examples, the network node includes a component for performing a contention-based random access procedure for a user equipment, the contention-based random access procedure comprising: receiving a random access request from the user equipment; sending a random access response to the user equipment; receiving a scheduled uplink transmission from the user equipment; sending a contention resolution to the user equipment; and the network node includes: a component for notifying the user equipment in downlink control information that the next contention resolution message is the last contention resolution message and that there is no subsequent retransmission of the contention resolution message.

[0036] In some but not necessarily all examples, an indication of disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure to at least the user equipment also indicates disabling at the user equipment of hybrid automatic request (HARQ) feedback for downlink messages transmitted after the downlink contention resolution message.

[0037] In some but not necessarily all examples, the network node is a transmission reception point.

[0038] In some but not necessarily all examples, the network node includes means for receiving an indication of a capability from a user equipment for disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention based random access (CBRA) procedure.

[0039] In some but not necessarily all examples, the network node comprises means for receiving an indication of the capability in an uplink message of a contention based random access procedure.

[0040] In some but not necessarily all examples, the network node comprises means for implicitly receiving an indication of capabilities via a constrained random access request in a contention based random access procedure.

[0041] In some but not necessarily all examples, the network node includes: means for receiving an indication of capability via a preamble for a random access request, wherein the preamble is selected from a first predefined subset to indicate a first capability and selected from a second predefined subset to indicate a lack of capability, and / or means for receiving an indication of capability using subcarriers for the random access request, wherein the subcarriers are selected from the first predefined subset to indicate the first capability and selected from the second predefined subset to indicate a lack of capability.

[0042] In some but not necessarily all examples, the network node comprises means for receiving an indication of capability via a scheduled uplink transmission in a contention based random access procedure.

[0043] According to various but not necessarily all examples, a method is provided that includes indicating to at least a user equipment disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure.

[0044] According to various but not necessarily all examples, a computer program is provided that includes instructions that, when executed on an apparatus, enable the apparatus to control: indicating to at least a user equipment that hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure is disabled at the user equipment.

[0045] According to various but not necessarily all examples, a user equipment is provided that includes means for indicating to a network node a disabled capability, the disabling being a disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure.

[0046] According to various but not necessarily all examples, a user equipment is provided, the user equipment comprising components for: receiving an indication from a network node that no retransmission of a downlink contention resolution message occurred in a contention-based random access procedure; and based on the received indication, a contention resolution timer is stopped in the contention-based random access procedure.

[0047] In some but not necessarily all examples, means for indicating that a retransmission of a downlink contention resolution message did not occur in a contention based random access (CBRA) procedure includes means for using downlink control information to indicate that the retransmission did not occur.

[0048] In some but not necessarily all examples, the user equipment includes means for modifying a HARQ-ACK resource field in the downlink control information to indicate that no retransmission has occurred.

[0049] According to various, but not necessarily all, examples, there is provided a network node comprising means for indicating to at least a user equipment that no retransmission of a downlink contention resolution message has occurred in a contention based random access procedure.

[0050] In some but not necessarily all examples, means for indicating that a retransmission of a downlink contention resolution message did not occur in a contention based random access (CBRA) procedure includes means for using downlink control information to indicate that the retransmission did not occur.

[0051] In some, but not necessarily all examples, the network node includes means for modifying a HARQ-ACK resource field in the downlink control information to indicate that no retransmission has occurred.

[0052] Examples are provided as claimed in the following claims according to various but not necessarily all examples.

[0053] Although the above examples and optional features of the present disclosure are described separately, it should be understood that all possible combinations and arrangements of them are included in the present disclosure. It should be understood that various examples of the present disclosure may include any or all features described with respect to other examples of the present disclosure, and vice versa. In addition, it should be understood that any one or more or all of these features may be implemented / included in / executable by devices, methods and / or computer program instructions in any combination as needed and when appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Some examples will now be described with reference to the accompanying drawings, in which:

[0055] Figure 1 An example of the subject matter described herein is shown;

[0056] Figure 2 Another example of the subject matter described herein is shown;

[0057] Figure 3 Another example of the subject matter described herein is shown;

[0058] Figure 4 Another example of the subject matter described herein is shown;

[0059] Figure 5 Another example of the subject matter described herein is shown;

[0060] Figure 6 Another example of the subject matter described herein is shown;

[0061] Figure 7 Another example of the subject matter described herein is shown;

[0062] Figure 8 Another example of the subject matter described herein is shown;

[0063] Fig. 9 Another example of the subject matter described herein is shown;

[0064] Fig.10 Another example of the subject matter described herein is shown;

[0065] Fig.11 Another example of the subject matter described herein is shown;

[0066] Fig.12 Another example of the subject matter described herein is shown;

[0067] Fig.13 Another example of the subject matter described herein is shown;

[0068] Fig.14 Another example of the subject matter described herein is shown;

[0069] The drawings are not necessarily to scale. For clarity and brevity, certain features and views of the drawings may be shown schematically or in scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to aid in explanation. Similar reference numerals are used in the drawings to indicate similar features. For clarity, not all reference numerals must be shown in all drawings. DETAILED DESCRIPTION

[0070] Figure 1 An example of a network 100 is illustrated, which includes a plurality of network nodes, including a terminal node 110, an access node 120, and one or more core nodes 129. The terminal node 110 and the access node 120 communicate with each other. The one or more core nodes 129 communicate with the access node 120.

[0071] In this example, the network 100 is a radio telecommunication network in which at least some of the terminal nodes 110 and the access nodes 120 communicate with each other using transmission / reception of radio waves.

[0072] In some examples, one or more core nodes 129 can communicate with each other. In some examples, one or more access nodes 120 can communicate with each other.

[0073] The network 100 may be a cellular network comprising a plurality of cells 122, each cell being served by an access node 120. The interface between the terminal node 110 and the access nodes 120 defining the cells 122 is a wireless interface 124 in this example.

[0074] The access node 120 is a cellular radio transceiver. The terminal node 110 is a cellular radio transceiver.

[0075] In the example shown, the cellular network 100 is a 3rd Generation Partnership Project (3GPP) network, wherein the terminal nodes 110 are user equipments (UEs) and the access nodes 120 are base stations.

[0076] In the particular example shown, the network 100 is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN consists of E-UTRAN NodeBs (eNBs) 120 to provide E-UTRA user plane and control plane (RRC) protocol terminations towards the UE 110. The eNBs 120 are interconnected to each other via an X2 interface 126. The eNBs are also connected to a Mobility Management Entity (MME) 129 via an S1 interface 128.

[0077] In other examples, the network 100 is a Next Generation (or New Radio NR) Radio Access Network (NG-RAN). The NG-RAN consists of gNodeBs (gNBs) 120 to provide user plane and control plane (RRC) protocol terminations towards the UE 110. The gNBs 120 are interconnected to each other via an X2 / Xn interface 126. The gNBs are also connected to an access and mobility management function (AMF) via an N2 interface 128.

[0078] User equipment includes mobile devices. Where reference is made to user equipment, the reference includes and encompasses reference to mobile devices where possible.

[0079] Figure 2 The diagram illustrates a communication process between the network node 120 and the user equipment.

[0080] The network node 120 is configured to indicate to the user equipment 110 a disabling 52 of a Hybrid Automatic Request (HARQ) feedback at the user equipment 110 for at least a downlink contention resolution message in a contention based random access (CBRA) procedure.

[0081] Although the network node 120 is illustrated as communicating with one user equipment 110, the network node 120 is configured to communicate simultaneously and in parallel with a plurality of user equipments 110. The network node 120 is configured to indicate to each of the plurality of user equipments 110 that a hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access (CBRA) procedure of the user equipment 110 is disabled 52 at the corresponding user equipment 110.

[0082] The user equipment 110 is configured to receive an indication 50 from the network node 120 to disable 52 at least a Hybrid Automatic Request (HARQ) feedback 20 of a downlink contention resolution message in a contention based random access (CBRA) procedure of the user equipment 110. The user equipment 110 is further configured to disable 52 at least a Hybrid Automatic Request (HARQ) feedback of a downlink contention resolution message in a contention based random access (CBRA) procedure according to the received indication 50.

[0083] Figure 3An example of a contention based random access (CBRA) procedure 60 with HARQ feedback (without HARQ feedback disabling) is illustrated. Figure 4 An example of a contention based random access (CBRA) procedure 60 with HARQ feedback disabling 52 is illustrated.

[0084] From the perspective of the user equipment 110, the contention-based random access (CBRA) procedure 60 includes:

[0085] (i) User equipment 110 sends a random access request (Msg1) 11;

[0086] (ii) the user equipment 110 receives the random access response (Msg2) 12;

[0087] (iii) the user equipment 110 sends a scheduled uplink transmission (Msg3) 13;

[0088] (iv) The user equipment 110 receives the contention resolution message (Msg4) 14.

[0089] The user equipment 110 sends a HARQ feedback message 20 acknowledging receipt of the contention resolution message (Msg4) 14.

[0090] From the perspective of the network node 120, the contention-based random access (CBRA) procedure 60 includes:

[0091] (i) The network node 120 receives the random access request (Msg1) 11;

[0092] (ii) The network node 120 sends a random access response (Msg2) 12;

[0093] (iii) the network node 120 receives the scheduled UL transmission (Msg3) 13;

[0094] (iv) The network node 120 sends a contention resolution message (Msg4) 14.

[0095] The network node 120 receives a HARQ feedback message 20 from the user equipment 110 confirming that the user equipment 110 received the contention resolution message (Msg4) 14.

[0096] Figure 4 An example of a contention based random access (CBRA) procedure 60 with HARQ feedback disabling 52 is illustrated. In this example, the user equipment 110 does not send a HARQ feedback message 20 acknowledging receipt of the contention resolution message (Msg4) 14. The network node 120 does not receive nor expects to receive a HARQ feedback message 20 from the user equipment 110 acknowledging receipt of the contention resolution message (Msg4) 14 by the user equipment 110.

[0097] The network node 120 is configured to indicate to the user equipment 110 disabling of Hybrid Automatic Request (HARQ) feedback 20 at the user equipment 110 for at least a downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60 .

[0098] The user equipment 110 is configured to receive an indication 50 from the network node 120 to disable 52 at least a hybrid automatic request (HARQ) feedback 20 of a downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60 of the user equipment 110. The user equipment 110 is further configured to disable 52 at least a hybrid automatic request (HARQ) feedback 20 of a downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60 according to the received indication 50.

[0099] The fact that the network node 120 does not expect to receive a HARQ feedback message 20 from the user equipment 110 confirming that the user equipment 110 received the contention resolution message (Msg4) 14 releases resources at the network node 120.

[0100] Figure 5 An example of a contention-based random access (CBRA) process 60 without HARQ feedback disabling is shown. The process 60 is similar to Figure 3 The process shown, however, Figure 5 In the embodiment, there is data communication associated with the CBRA procedure 60. After the network node 120 sends the downlink contention resolution message 14 to the user equipment 110, the network node 120 may then send the downlink data message 30 to the user equipment 110.

[0101] There are separate HARQ processes for the downlink contention resolution message 14 and the downlink data message 30. Therefore, when the user equipment 110 successfully receives the downlink contention resolution message 14, it sends a first HARQ feedback message 20 as an acknowledgement to the network node 120. When the user equipment 110 successfully receives the downlink data message 40, it sends a second HARQ feedback message 20 as an acknowledgement to the network node 120.

[0102] Although in this example, the first HARQ feedback message 20 is illustrated as being sent within the time interval between the network node 120 sending the downlink contention resolution message 14 and sending the downlink data message 40, in some examples, the first HARQ feedback message 20 is not sent within the time interval between the user equipment 110 sending the downlink contention resolution message 14 and sending the downlink data message 40, but is sent after the network node sends the downlink data message 40. For example, the timing sequence depends on the communication distance (communication delay) between the network node 120 and the user equipment 110.

[0103] Therefore, it should be understood that the HARQ feedback message 20 may be relative to Figure 5 The timing shown is delayed.

[0104] It should also be appreciated that the network node 120 may retransmit the downlink contention resolution message 14 if the HARQ feedback message 20 is not received in a timely manner.

[0105] In some examples, the network node 120 sends a downlink contention resolution message 14 to the user equipment 110, and the user equipment 110 may then send an uplink data message to the network device (not shown).There is typically no HARQ process associated with uplink transmissions.

[0106] Hence, the disabling of HARQ feedback messages 30 refers to the disabling of HARQ feedback messages 30 sent in the uplink direction relative to previous messages received in the downlink direction.

[0107] Figure 6 FIG. 1 shows a schematic diagram of a HARQ feedback disabled configuration as previously described with reference to FIG. Figure 5 An example of a contention based random access (CBRA) procedure 60 is described.

[0108] The first HARQ process of the downlink contention resolution message 14 is disabled 52. Therefore, when the user equipment successfully receives the downlink contention resolution message 14, it does not send the first HARQ feedback message 20 to the network node 120 as a response.

[0109] The second HARQ process of the downlink data message 30 is disabled 52 .

[0110] When the user equipment 110 successfully receives the downlink data message 40, it does not send a second HARQ feedback message 20 to the network node 120 as a response.

[0111] Figure 6 The process 60 shown is similar to Figure 4 The process shown, however, Figure 6In the embodiment, there is data communication associated with the CBRA procedure 60. After the network node 120 sends the downlink contention resolution message 14 to the user equipment 110, the network node 120 subsequently sends the downlink data message 30 to the user equipment 110.

[0112] Therefore, it can be understood that in this example, the user equipment 110 is also configured to disable the hybrid automatic request (HARQ) feedback 20 of the downlink data message 30 after the contention resolution message (Msg4) according to the received indication 50.

[0113] The user equipment 110 is configured to, in response to receiving an indication 50 from the network node 120, disable a hybrid automatic request (HARQ) feedback 20 for a contention resolution message (Msg4) 14, and also disable a hybrid automatic request (HARQ) feedback 20 for a downlink data message 30 that is received after the contention resolution message (Msg4) but is associated with a CBRA procedure 60.

[0114] The downlink data message 30 transmitted after the downlink (DL) contention resolution message 14 may be, for example, a DLInformationTransfer message in the control plane of the NB-IoT UE.

[0115] The downlink data message 30 transmitted after the downlink (DL) contention resolution message 14 may be, for example, a DL early data transmission.

[0116] In at least some examples, the indication 50 indicates disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for downlink messages (eg, downlink data messages 30 ) transmitted after the downlink contention resolution message 14 .

[0117] Figure 7 and Figure 8 An example of an indication 50 is illustrated, wherein the indication 50 indicates a disabling 52 at the user equipment. That is, the indication 50 is an unconditional command to disable 52 the uplink HARQ feedback message 20. Fig. 9 An example of an indication 50 is illustrated, wherein the indication 50 provides a condition for the user equipment 110 to determine whether to disable 52 uplink HARQ feedback messages 20 .

[0118] exist Figure 7In the example shown, the indication 50 is provided by downlink control information (DCI) 40. Downlink control information is a message sent from a network node 120 to a specific user equipment 110, e.g. based on a network schedule, for configuring the operation of the specific user equipment 110. In 3GPP, DCI is sent on a physical downlink control channel (PDCCH).

[0119] For example, the indication 50 may be a downlink control information (DCI) field for re-conditioning purposes.

[0120] For example, the indication 50 may use a downlink control information (DCI) field associated with the CBRA procedure 60. For example, the indication 50 may use a downlink control information (DCI) field associated with the scheduling contention resolution message (Msg4) 14.

[0121] In some examples, the indication 50 is downlink control information (DCI) 40 used to schedule a downlink contention resolution message 14, which is repurposed to indicate disabling 52 of hybrid automatic request (HARQ) feedback 20 for at least a downlink contention resolution message (Msg4) 14 in a contention-based random access (CBRA) procedure 60.

[0122] In some examples, the indication 50 is downlink control information (DCI) 40 that includes a modified HARQ-ACK resource field.

[0123] The modification of the downlink control information (DCI) field (used as an indicator 50 of the disabling 42 of HARQ feedback) may be indicated, for example, in the broadcast system information (SIB), or predefined in the specification. For example, which value of the "HARQ-ACK resources" field is defined to indicate HARQ feedback disabling may be indicated by SIB signaling, or defined in the specification.

[0124] In the example shown, but not necessarily all examples, DCI 40 has format N1.

[0125] exist Figure 8 In the example shown, the indication 50 is provided by the random access response message 12 in the CBRA procedure 60. The random access response message 12 used as the indication is Msg2 in the CBRA procedure 60, and the HARQ feedback 20 of at least the contention resolution message 14 (Msg4 in the same CBRA procedure 60) is disabled 52. The indication 50 is a modified downlink random access response 12 in the contention based random access (CBRA) procedure 60. For example, the indication 50 may be provided as a flag or a bit field in the modified downlink random access response 12.

[0126] exist Figure 8In the example shown, the indication 50 includes the received broadcast system information 42. The system information 42 is broadcast to a plurality of user equipments 110. In the example shown, the broadcast system information 42 is included in a broadcast system information block (SIB). The SIB is transmitted using a broadcast control channel (BCCH), which is mapped on a downlink shared channel (DL-SCH), which in turn is mapped on a physical downlink shared channel (PDSCH).

[0127] In some but not necessarily all examples, the broadcast system information 42 provides conditions for the user equipment to determine the disabling.

[0128] In some, but not necessarily all, examples, the broadcast system information 42 defines one or more thresholds 54 for evaluating 56 a downlink signal 42 at the user equipment 110. The evaluation 56 of the downlink signal 42 may be, for example, a measurement of received power, such as a reference signal received power (RSRP). In this example, the downlink signal 42 is a reference signal, such as a secondary synchronization signal (SSS). In some examples, other evaluations of reference signals may be used, or other downlink signals may be evaluated.

[0129] If the RSRP measured at the user equipment 110 is low (below a threshold), there may be more repetitions in the HARQ process. The network may remain busy and HARQ stalling is less likely to occur. Therefore, disabling 52 of the HARQ process is not required.

[0130] If the RSRP measured at the user equipment is high (above a threshold), there may be no or limited repetitions in the HARQ process. The network may be stuck waiting for the HARQ feedback message 20. Therefore, disabling 52 of the HARQ process is required.

[0131] Hence, if the user equipment assesses that the downlink channel is reliable, for example the user equipment measures RSRP above a threshold, it disables 52 the HARQ process 20 .

[0132] The user equipment may reuse the threshold value provided for other purposes. For example, the user equipment may reuse the threshold value provided for determining the coverage enhancement (CE) level.

[0133] In some examples, the broadcast system information 42 defines one or more coverage enhancement (CE) levels, and at least one coverage enhancement (CE) level is associated with disabling 52 of HARQ feedback 20 .

[0134] For example, a low CE level (better RSRP) may result in the disabling 52 of the HARQ process 20 , while a high CE level (worse RSRP) may prevent the disabling 52 of the HARQ process 20 .

[0135] The shorter the transmission time per packet (including repetitions), the more likely it is to cause stalls. Therefore, transmissions with limited repetitions are more likely to disable HARQ feedback.

[0136] Fig.10 A contention based random access (CBRA) procedure 60 is illustrated, for example as previously described.

[0137] When HARQ feedback is enabled, there is HARQ feedback for contention resolution message (Msg4) 14. The network node 120 repeats contention resolution message (Msg4) 14 multiple times and stops when HARQ feedback message 20 is received. When HARQ feedback is disabled, the network node 120 blindly repeats contention resolution message (Msg4) 14 multiple times without waiting for HARQ feedback message. After sending the scheduled UL transmission (Msg3) 13, the user equipment 110 waits to receive a downlink contention resolution message (Msg4) 14. It waits for the original contention resolution message (Msg4) 14 or a retransmission of the contention resolution message (Msg4) 14. For example, after sending the scheduled UL transmission (Msg3) 13, the user equipment 110 starts a contention resolution timer and waits to receive the contention resolution message (Msg4) 14 until the contention resolution timer expires or the contention resolution message (Msg4) 14 is received. When the contention resolution timer expires or the contention resolution message (Msg4) 14 is received, the waiting for receiving the contention resolution message (Msg4) 14 is terminated.

[0138] In at least some examples, the network node 120 notifies 92 the user equipment 110 of the use of an alternative condition to terminate the wait for receiving the contention resolution message (Msg4) 14. For example, the network node 120 may notify 92 the user equipment 110 that the next (or specified) contention resolution message (Msg4) 14 will be the last contention resolution message (Msg4) 14 and there will be no more retransmissions of the contention resolution message (Msg4) 14.

[0139] This enables the network node 120 to stop retransmission of the contention resolution message (Msg4) 14 without receiving the HARQ feedback message 20 indicating reception of the contention resolution message (Msg4) 14 at the user equipment 110.

[0140] In at least some examples, Fig.10 As shown, the user equipment 110 is configured to determine 90 from the downlink control information 40 that the next sent contention resolution message 14 is the last sent contention resolution message 14 and there is no subsequent retransmission of the contention resolution message 14. Therefore, the user equipment can stop its contention resolution timer (e.g., mac-ContentionResolutionTimer in 3GPP).

[0141] The next contention resolution message 14 sent may be the original contention resolution message 14 sent for the first time, or may be a retransmission of the contention resolution message 14 .

[0142] The user equipment 110 is configured to determine from the downlink control information 40 that the contention resolution message 14 is sent without subsequent retransmission.

[0143] The DCI 40 may be modified to inform the user equipment 110 that the next contention resolution message 14 sent is the last contention resolution message 14 sent and that there are no subsequent retransmissions of the contention resolution message 14 .

[0144] For example, the HARQ-ACK resources field in the downlink control information (DCI) 40 may be modified to indicate that no retransmission has occurred. Which value of the "HARQ-ACK resources" field is defined to indicate that it may be indicated by SIB signaling or defined in the specification.

[0145] The user equipment 110 determines from the downlink control information 40 that the contention resolution message 14 is sent without subsequent retransmission.

[0146] A bit in DCI format N1 (which is used to indicate NPDSCH (e.g., Msg4) transmission related parameters and NPUSCH format 2 related parameters) can be redefined to indicate whether there will be further retransmissions after the grant. The network node 120 can notify 92 the user equipment 110 via DCI40 that the current grant is the last attempt for Msg4 transmission (retransmission). Therefore, the user equipment knows whether future retransmissions are expected. If subsequent retransmissions are not expected, the contention resolution timer can be stopped in advance to save power consumption of the user equipment.

[0147] Therefore, the user equipment 110 is configured to receive an indication 92 from the network node 120 that no retransmission of the downlink contention resolution message (Msg4) 14 occurs in the contention-based random access (CBRA) process 60; and according to the received indication 92, stop the contention resolution timer in the contention-based random access (CBRA) process 60.

[0148] The downlink control information 40 may be used as the indication 92. The HARQ-ACK resources field in the downlink control information 40 may be modified to provide the indication 92. The value of the "HARQ-ACK resources" field defined as the indication 92 may be indicated through system information (SIB) signaling or defined in the specification.

[0149] Fig.11An example is illustrated in which a user equipment 110 is configured to indicate to a network node 120 a disabled capability 70 at the user equipment 110 for a hybrid automatic request (HARQ) feedback 20 for at least a downlink contention resolution message (Msg4) 14 in a contention based random access (CBRA) procedure 60 .

[0150] For example, the indication of the capability 70 may occur as part of a CBRA procedure 60 for which hybrid automatic request (HARQ) feedback 20 is to be disabled. In some examples, the user equipment 110 is configured to use an uplink message of a contention-based random access (CBRA) procedure to indicate the capability 70 of disabling 52 of HARQ feedback 20 at the user equipment 110. For example, using a random access request (Msg1) 11 and / or a scheduled uplink transmission (Msg3) 13.

[0151] In some examples, the user equipment 110 is configured to indicate a capability 70 of disabling 52 at the user equipment 110 for HARQ feedback 20 by restricting detectable characteristics of the random access request (Msg1) 11 in a contention based random access (CBRA) procedure 60. The purposeful restriction of the detectable characteristics conveys information that can be used to indicate the capability 70.

[0152] In some examples, user equipment 110 is configured to provide an implicit indication of capabilities 70 .

[0153] In some examples, the user equipment 110 is configured to indicate an ability 70 to disable 52 at the user equipment 110 for HARQ feedback 20 by selecting between different configurations for a random access request 11 in a contention based random access (CBRA) process 60, wherein a first set of configurations indicates the ability to disable 52 and a second set of configurations indicates a lack of the ability to disable 52.

[0154] Different configurations of the random access request 11 may include one or more of the following:

[0155] Different preamble sequences for random access request 11,

[0156] Different time-frequency domain resources for random access request 11;

[0157] A different subcarrier is used for the first transmission (in NB-IoT, this first subcarrier defines the remaining subcarriers used for frequency hopping during the preamble transmission).

[0158] Random access is performed according to a configuration that defines periodic occasions in the time domain where the user equipment 110 can select between a certain number of subcarriers.

[0159] In some examples, user equipment 110 is configured to provide an implicit indication of capability 70 by selecting a preamble for random access request 11 from a first predefined subset to use to indicate a first capability, and selecting a preamble for random access request (Msg1) from a second predefined subset to indicate a second capability (e.g., no capability), and / or providing an implicit indication of capability 70 by selecting a subcarrier for random access request 11 from a first predefined subset to use to indicate the first capability, and selecting a subcarrier for random access request (Msg1) 11 from a second predefined subset to indicate the second capability (e.g., no capability), and / or providing an implicit indication of capability 70 by selecting a time domain resource for random access request from a first predefined subset to use to indicate the first capability, and a component for selecting a time domain resource for random access request from a second predefined subset to indicate the second capability (e.g., no capability).

[0160] The second predefined subset is different from (exclusive of) the corresponding first predefined subset.

[0161] In some examples, user equipment 110 is configured to provide an implicit indication of capability 70 by:

[0162] i) selecting a combination of features (e.g., preamble and / or subcarrier and / or time domain resource) for the random access request 11 from a first predefined subset to indicate a first capability,

[0163] ii) Selecting a combination of features (eg, preamble and / or subcarriers and / or time domain resources) for the random access request 11 from a second predefined subset (different from the first subset) to indicate a second capability (eg, no capability).

[0164] In some examples, user equipment 110 is configured to provide an explicit indication of capabilities 70 .

[0165] In some examples, user equipment 110 is configured to indicate to the network a capability to disable 52 at user equipment 110 for hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60, using an explicit indication of capability 70, by adapting a scheduled uplink transmission 13 in a contention based random access (CBRA) procedure 60.

[0166] For example, adapting the scheduled uplink transmission 13 may provide the indication as a flag, or a modified bit field.For example, one bit may be dedicated to a HARQ feedback disabling flag.

[0167] In some examples, the user equipment 110 affirmatively indicates to the network a capability of disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution messages 14 in a contention based random access (CBRA) procedure 60. Thus, the network node is enabled to provide an indication 50 to the user equipment 110 to indicate disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution messages in a contention based random access (CBRA) procedure 60.

[0168] In some examples, the user equipment 110 negatively indicates to the network a capability of disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60. The user equipment 110 indicates a lack of capability. Thus, the network node is prevented from providing an indication 50 to the user equipment 110 to indicate disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution message in a contention based random access (CBRA) procedure 60.

[0169] In some examples, the user equipment 110 negatively indicates to the network a capability of disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution message 14 in a contention based random access (CBRA) procedure 60. However, the network node is enabled to provide an indication 50 to the user equipment 110 to indicate disabling 52 at the user equipment 110 of hybrid automatic request (HARQ) feedback 20 for at least downlink contention resolution message in a contention based random access (CBRA) procedure 60. However, the user equipment 110 does not respond to the indication 50 and does not disable 52 the HARQ process. The user equipment 110 should follow its own capabilities and still attempt HARQ feedback transmission 20.

[0170] In some examples, the network node 120 is configured to mitigate the effects of HARQ stalling. HARQ stalling occurs when the network is waiting for the completion of a HARQ process (waiting to receive a HARQ feedback message 20), but this waiting is inefficient because, for example, the waiting time is long when it is unlikely that a HARQ feedback message will be received. For example, this may be because the transmission delay between the user equipment 110 and the network node 120 is long (the distance is large).

[0171] The network or network node 120 may be configured to determine HARQ stagnation or a likelihood of HARQ stagnation. In the event that the likelihood exceeds a threshold, the network node may send an indication 50 to the user equipment 110 to indicate a disabling 52 of a hybrid automatic request (HARQ) feedback 20 at the user equipment 110 for at least a downlink contention resolution message 14 in a contention-based random access (CBRA) procedure 60. The indication is sent in accordance with determining HARQ stagnation or a likelihood of HARQ stagnation.

[0172] In some examples, the indication is sent based on a measured or expected transmission delay between the network node 120 and the user equipment 110 .

[0173] In the above example, the user equipment 110 / network node 120 may be, for example, a user equipment / network node 120 that complies with the standardized requirements of Narrowband Internet of Things (NB-IoT). Narrowband Internet of Things (NB-IoT) is a standard-based low-power wide-area (LPWA) technology that aims to enable a wide range of new IoT devices and services. NB-IoT significantly improves the power consumption of user equipment, system capacity, and spectrum efficiency.

[0174] In the above examples, the user equipment 110 / network node 120 may be, for example, a user equipment / network node 120 compliant with 5G New Radio Reduced Capability User Equipment (5G NR RedCap or 5G NR Lite).

[0175] In the above example, the user equipment 110 (and the network node 120 ) may be, for example, a user equipment (network node 120 ) that complies with enhanced machine type communication (eMTC) standardization requirements.

[0176] In the above example, the user equipment 110 (and the network node 120) may be, for example, a user equipment (network node 120) that complies with the standardization requirements of the Internet of Things Non-Terrestrial Network (IoT NTN). This provides narrowband Internet of Things (NB-IoT) / enhanced machine type communication (eMTC) support for the non-terrestrial network (NTN).

[0177] In the above examples, the network node 120 and the user equipment may be part of a very large scale network, for example, where the distance between them exceeds 100 km.

[0178] In the above examples, the network node 120 may be, for example, a node of a non-terrestrial network (NTN). The network node 120 may be, for example, a node of a satellite network.

[0179] In some satellite networks, base stations are located on the earth and the satellite acts as a relay. In some satellite networks, base stations are located on satellites. Thus, network node 120 can be on the earth or on a satellite.

[0180] For example, the satellite may be a low earth orbit (LEO) satellite (with an altitude of 300 km-1500 km). For example, the satellite may be a geosynchronous orbit (GEO) satellite (with an altitude of about 36,000 km).

[0181] In the above examples, the network node 120 may be any transmission reception point, such as a user equipment, a relay or a base station.

[0182] The user equipment 110 may be an Internet of Things (IoT) device. Such a device has low complexity, low cost, low power consumption and low throughput, and the key requirements for IoT services are extended coverage, delay tolerance and infrequent data transmission, and support for large-scale communications. Disabling uplink HARQ feedback 20 as a response to downlink transmission is beneficial to reduce power consumption and latency of the user equipment. It also improves uplink throughput in the NTN because more resources are available in the uplink.

[0183] Disabling HARQ feedback 20 for downlink transmissions can alleviate HARQ stalls due to long round trip time (RTT) in NTNs, which will be beneficial to reducing UE power consumption and latency.

[0184] Fig.12 The network node 120 and the user equipment (UE) 110 support HARQ feedback disabling for Msg4 14 in the CBRA 60, and subsequent signaling radio bearer (SRB) scheduling.

[0185] HARQ feedback disabling can be supported in control plane (CP) solution, user plane solution and early data transmission (EDT). It enables subsequent SRB / RRC to be quickly scheduled to send data in time, thereby reducing data transmission time and saving UE energy consumption and uplink resources.

[0186] The CP solution (i.e., control plane CIoT EPS / 5GS optimization) is an important feature of NB-IoT, which enables support of user data (IP, non-IP) or SMS messages on the control plane via the Mobility Management Entity (MME) without triggering data radio bearer establishment. The characteristics of the control plane CIoT EPS optimization of NB-IoT UE are: no support for RRC connection reconfiguration; no use of data radio bearer (DRB); no use of AS security; non-anchor carriers can be configured for all unicast transmissions during RRC connection establishment or reestablishment. In the CP solution, UL / DL NAS messages carrying small data can be sent through UL / DL RRC container messages (e.g., RRCConnectionSetupComplete and / or ULinformationTransfer / DLInformationTransfer in SRB1), and DRBs are not used. Therefore, it can reduce the total time for small data transmission.

[0187] NB-IoT / eMTC supports an Early Data Transfer (EDT) function, where a single-user packet is sent during the RACH procedure 60. Since no RRC connection is established for EDT (i.e., no transition to RRC CONNECTED), this is a more energy-efficient small data transfer procedure. There are two types of EDT: MT-EDT and MO-EDT. MT-EDT is initiated by the MME, and there is a single downlink data transfer during the random access procedure 60. When higher layers have requested to establish or resume an RRC connection for mobile originated data (i.e., not signaling or SMS), MO-EDT is triggered, and one uplink data transfer is optionally allowed during the random access procedure 60, followed by one downlink data transfer. For MT-EDT, the RAN will trigger a paging message for EDT, and the UE will then initiate the MO EDT procedure and send a paging response.

[0188] Both NB-IoT CP solution and EDT enable efficient data transmission between IoT devices and IoT applications / services, thereby saving UE energy consumption. However, in IoT over NTN, HARQ stalling may occur due to long RTT (up to 540ms in GEO) and small number of HARQ processes (1 or 2 HARQ processes for NB1 and NB2 categories respectively) when the required channel transmission time is less than RTT. Due to high RTT, it may also cause scheduling delays after Msg4 (e.g., NW has to wait for UE's HARQ feedback for Msg4), which will delay the scheduling and transmission of consecutive UL / DL RRC container messages by at least one RTT in the CP solution. Therefore, introducing HARQ feedback disabling for Msg4 will be beneficial because it can quickly schedule subsequent SRB / RRC to send data in time, thereby reducing data transmission time and saving UE energy consumption. For EDT, disabling HARQ feedback is also beneficial because it will further reduce UE energy consumption because the UE will not send HARQ feedback repetitions.

[0189] exist Fig.12 In the example shown, the user equipment 110 and the network node 120 communicate according to NB-IoT.

[0190] A narrowband primary synchronization signal (NPSS) 71, a narrowband secondary synchronization signal (NSSS) 72, and a narrowband physical broadcast channel signal (NPBCH) 73 are sent from the network node 120 to the user equipment 110 to enable initial synchronization and master system information acquisition. The NB-IoT UE uses NPSS and NSSS to perform cell search, including time and frequency synchronization and cell identity detection. The NPBCH carries the master information block (MIB) and is sent in subframe #0 of each frame.

[0191] Next, the CBRA process 60 is performed using the data downlink 30 but not using the uplink HARQ feedback message of the downlink Msg4 14 or the downlink data message 30. The CBRA process 60 has been described.

[0192] The user equipment 110 sends a UL NAS message carrying small data in a UL container message 74 (eg, RRCConnectionSetupComplete) and does not use DRBs.

[0193] The network node 120 sends a DL NAS message (DL data message 30) carrying small data in a DL RRC container message 75 (eg, ULinformationTransfer / DLInformationTransfer in SRB1) and does not use DRBs.

[0194] The UE 110 indicates its HARQ feedback disabling capability 50 to the network before Msg4 14. The UE 110 indicates support for HARQ feedback disabling in Msg3 13 or Msg1 11.

[0195] For Msg1, if the UE supports HARQ feedback disabling for Msg4, the UE 110 will select a preamble from the dedicated preamble set, and if the UE does not support HARQ feedback disabling, the UE will select another preamble. Based on the UE's transmission of the preamble in Msg1 11, the network (NW) will implicitly know the UE's ability to disable HARQ feedback for Msg4 based on the preamble received from the UE. In addition to / instead of the preamble sequence, the implicit indication via the preamble set can also be based on selecting a specific RACH resource in the time domain and / or frequency domain.

[0196] The capability of HARQ feedback disabling for each CE level may be indicated. For example, in Msg1, the network may configure a dedicated preamble set for each coverage enhancement (CE) level of the UE to indicate that the UE can support HARQ feedback disabling. The NW may configure a dedicated preamble set for each coverage enhancement (CE) level to enable the UE to indicate that the UE can support HARQ feedback disabling.

[0197] Alternatively, the UE 110 may indicate support for HARQ feedback, for example via a bit flag, in Msg3 13. For example, one bit may be dedicated to a HARQ feedback disabling flag.

[0198] The NW 120 indicates HARQ feedback disabling for Msg4 and subsequent SRB scheduling. The network may indicate HARQ feedback disabling in DCI / SIB / Msg4.

[0199] Coverage Enhancement (CE) is a feature of NB-IoT networks, where each base station (BS) divides its IoT devices into up to three coverage groups with different RSRP ranges. Many features (such as repetition of random access procedures, PDCCH, PDSCH and PUSCH, and uplink power control) are closely related to the coverage level. Setting different channel repetition numbers in different CE levels can achieve very different coverage enhancements, for example:

[0200] Coverage enhancement level 0 (normal) → +0dB for coverage enhancement, MCL < 144dB

[0201] Coverage enhancement level 1 (robust) → +10dB for coverage enhancement, 144dB <MCL<154dB

[0202] Coverage enhancement level 2 (extreme) → +20dB for coverage enhancement, MCL>154dB

[0203] Since the HARQ stagnation problem may only occur with few channel repetitions (stagnation is unlikely), HARQ feedback disabling may depend on the coverage enhancement (CE) level of the IoT UE and only apply to specific coverage enhancement levels. For example, for high coverage enhancement levels with lower RSRP / larger MCL and more repetitions, HARQ stagnation is unlikely to occur and HARQ feedback enabling may be applied. For low coverage enhancement levels with higher RSRP / smaller maximum coupling loss (MCL) and fewer repetitions, HARQ stagnation is more likely to occur and HARQ feedback disabling may be applied. The network knows the CE level of the UE based on the RA preamble transmission.

[0204] The HARQ feedback disabling / enabling per CE level may be indicated by SIB signaling (ie, in each CE level configuration). It may be defined in the specification that the HARQ feedback disabling / enabling applies only to one or two coverage enhancement levels.

[0205] HARQ feedback disabling may depend on the coverage enhancement (CE) level of the IoT UE 110 and may only be applied to a specific coverage enhancement level. For example, for CE level 0 with higher RSRP / smaller MCL (e.g., MCL<144dB), HARQ stagnation is more likely to occur due to the smaller number of repetitions, so HARQ feedback disabling may be applied. For CE level 2 with lower RSRP / larger MCL (e.g., MCL>154dB), HARQ stagnation is less likely to occur due to the larger number of repetitions, so HARQ feedback enabling may be applied.

[0206] The network node 120 is configured to control HARQ feedback disabling / enabling for each coverage level in SIB signaling and current signaling of two thresholds in rsrp-ThresholdsPrachInfoList. The UE will determine the CE level based on the measured RSRP and the two signaled RSRP thresholds, and then obtain HARQ feedback disabling or enabling based on the CE level.

[0207] Another embodiment is to define in the specification whether each coverage level applies HARQ feedback disabling or enabling. For example, in the specification, coverage level 0 and coverage level 1 are defined with HARQ feedback disabling, and coverage level 2 is defined with HARQ feedback enabling.

[0208] Alternatively, HARQ feedback disable / enable is indicated in Msg2 12.

[0209] In one option, a DCI-based HARQ feedback disable / enable signaling solution can be used to indicate HARQ feedback disable / enable for Msg4, since this solution does not require RRC configuration / reconfiguration. The "HARQ-ACK resources" in DCI format N1 can be redefined to indicate HARQ feedback disable / enable.

[0210] For DL ​​HARQ operation, when HARQ feedback for the HARQ process is disabled, DL HARQ feedback (i.e., ACK / NACK) carried by narrowband physical uplink shared channel (NPUSCH) format 2 will not be sent. Therefore, the DCI field "HARQ-ACK resources" indicating the time-frequency resources of the NPUSCH used to carry the ACK / NACK response will not be used. A value of the current "HARQ-ACK resources" field may be redefined to indicate HARQ feedback disabling. The function of the field "HARQ-ACK resources" being redefined to indicate HARQ feedback disabling / enabling, and which value of the "HARQ-ACK resources" field is defined to indicate HARQ feedback disabling may be indicated by SIB signaling or defined in the specification.

[0211] Furthermore, to further reduce the energy consumption of the UE, the network node 120 may indicate 92 that no Msg4 retransmission has occurred in the DCI 40. One bit in DCI format N1 (which is used to indicate both narrowband physical downlink shared channel (NPDSCH) transmission related parameters and NPUSCH format 2 related parameters) may be redefined to indicate whether there will be further retransmissions after the grant.

[0212] In IoT over NTN, if Msg3 13 is sent, the media access control (MAC) entity in the user equipment 110 shall start / restart the mac-ContentionResolutionTimer at each HARQ retransmission of a bundle in the subframe corresponding to the last subframe of the PUSCH transmission corresponding to the maximum TBS indicated by the UL grant, plus the UE-eNB RTT subframe. The UE shall monitor the PDCCH until the mac-ContentionResolutionTimer expires or stops. With this information, the UE can stop the contention resolution timer earlier to save power consumption of the UE.

[0213] Since whether to schedule more Msg4 retransmissions is a scheduling decision of the NW, if the NW decides to stop Msg4 scheduling after the current grant, the NW can inform the UE that the current grant is the last attempt for Msg4 transmission (retransmission). With this information, after decoding the corresponding NPDSCH, if the contention resolution is unsuccessful, the UE can stop the contention resolution timer in advance to save UE power consumption.

[0214] The described examples enable efficient data transmission between IoT devices and IoT applications / services for CP solutions and EDT to save energy consumption of UEs in IoT NTNs with high RTT.

[0215] The described examples introduce solutions for supporting HARQ feedback disabling and subsequent SRB scheduling of Msg4, including how the UE indicates the HARQ feedback disabling UE capability to the network before Msg4 14, and a signaling solution for indicating HARQ feedback disabling. With these solutions, HARQ feedback disabling can be supported in the CP solution and EDT, and subsequent SRB / RRC can be quickly scheduled to send data in time.

[0216] In addition, when the HARQ feedback of Msg4 is disabled, the NW does not allocate uplink resources for HARQ feedback, and the NW can schedule UL grant (for example, for Msg5) to implicitly feedback that Msg4 is successfully decoded, which is beneficial to saving power consumption and UL resources.

[0217] The above examples may affect standardization, for example:

[0218] Signaling for indicating HARQ feedback disabling;

[0219] UE capability reporting with HARQ feedback disabled;

[0220] signaling to indicate that no retransmission has occurred; and

[0221] UE behavior when indicating that no retransmission has occurred.

[0222] Independent claims may be filed for a user equipment comprising means for:

[0223] receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and

[0224] According to the received indication, hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message is disabled in a contention-based random access procedure.

[0225] Independent claims may be filed for a network node comprising means for:

[0226] Disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure is indicated to at least the user equipment.

[0227] Independent claims may be filed for a user equipment comprising means for:

[0228] A disabled capability is indicated to a network node, the disabled being a disabled hybrid automatic request (HARQ) feedback at a user equipment for at least a downlink contention resolution message in a contention based random access procedure.

[0229] Independent claims may be made for a network node comprising means for:

[0230] Indicating to at least the user equipment that no retransmission of the downlink contention resolution message occurred in the contention-based random access procedure.

[0231] Independent claims may be made for user equipment comprising means for:

[0232] receiving an indication from the network node that no retransmission of a downlink contention resolution message occurred in a contention based random access procedure; and

[0233] According to the received indication, a contention resolution timer is stopped in the contention-based random access procedure.

[0234] Fig.13 An example of a controller 400 suitable for use with devices 110, 120 is shown. An implementation of the controller 400 may be a controller circuit system. The controller 400 may be implemented solely in hardware, have certain aspects in software including separate firmware, or may be a combination of hardware and software (including firmware).

[0235] like Fig.13 As shown, the controller 400 may be implemented using instructions that enable hardware functionality, for example, by using executable instructions of a computer program 406 in a general or special purpose processor 402, which may be stored on a computer readable storage medium (disk, memory, etc.) for execution by such processor 402.

[0236] The processor 402 is configured to read from and write to the memory 404. The processor 402 may also include an output interface via which data and / or commands are output by the processor 402 and an input interface via which data and / or commands are input to the processor 402.

[0237] The memory 404 stores a computer program 406, which includes computer program instructions (computer program code) that control the operation of the apparatus 110, 120 when loaded into the processor 402. The computer program instructions of the computer program 406 provide logic and routines that enable the apparatus to perform the method shown in the drawings. The processor 402 can load and execute the computer program 406 by reading the memory 404.

[0238] The device 120 comprises:

[0239] at least one processor 402; and

[0240] at least one memory 404 comprising computer program code;

[0241] The at least one memory 404 and the computer program code are configured to, together with the at least one processor 402, cause the apparatus 120 to at least perform:

[0242] Disabling of Hybrid Automatic Request (HARQ) feedback at the user equipment 110 for at least the downlink contention resolution message 14 in the contention-based random access procedure 60 is indicated to at least the user equipment 110 .

[0243] The device 110 comprises:

[0244] at least one processor 402; and

[0245] at least one memory 404 comprising computer program code;

[0246] The at least one memory 404 and the computer program code are configured to, together with the at least one processor 402, cause the apparatus 110 to at least perform:

[0247] receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and

[0248] Means for disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure in accordance with the received indication.

[0249] The device 110 comprises:

[0250] at least one processor 402; and

[0251] at least one memory 404 comprising computer program code;

[0252] The at least one memory 404 and the computer program code are configured to, together with the at least one processor 402, cause the apparatus 110 to at least perform:

[0253] A disabled capability is indicated to a network node, the disabled being a disabled hybrid automatic request (HARQ) feedback at a user equipment for at least a downlink contention resolution message in a contention based random access procedure.

[0254] like Fig.14 As shown, the computer program 406 may arrive at the apparatus 110, 120 via any suitable delivery mechanism 408. The delivery mechanism 408 may be, for example, a machine-readable medium, a computer-readable medium, a non-transitory computer-readable storage medium, a computer program product, a memory device, a recording medium (such as a compact disk read-only memory (CD-ROM) or a digital versatile disk (DVD) or a solid-state memory, etc.), an article of manufacture that includes or tangibly embodies the computer program 406. The delivery mechanism may be a signal configured to reliably transmit the computer program 406. The apparatus 110, 120 may propagate or send the computer program 406 as a computer data signal.

[0255] Computer program instructions for causing the apparatus 120 to at least perform the following operations or for at least performing the following operations:

[0256] Disabling of Hybrid Automatic Request (HARQ) feedback at the user equipment 110 for at least the downlink contention resolution message 14 in the contention-based random access procedure 60 is indicated to at least the user equipment 110 .

[0257] Computer program instructions for causing the apparatus 110 to at least perform the following or for performing the following:

[0258] receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and

[0259] Means for disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure in accordance with the received indication.

[0260] Computer program instructions for causing the apparatus 110 to at least perform the following or for performing the following:

[0261] A disabled capability is indicated to a network node, the disabled being a disabled hybrid automatic request (HARQ) feedback at a user equipment for at least a downlink contention resolution message in a contention based random access procedure.

[0262] The computer program instructions may be included in a computer program, a non-transitory computer readable medium, a computer program product, a machine readable medium. In some but not necessarily all examples, the computer program instructions may be distributed over multiple computer programs.

[0263] Although memory 404 is illustrated as a single component / circuitry, it may be implemented as one or more separate components / circuitry, some or all of which may be integrated / removable, and / or may provide permanent / semi-permanent / dynamic / cached storage.

[0264] Although processor 402 is illustrated as a single component / circuitry, it may be implemented as one or more separate components / circuitry, some or all of which may be integrated / removable.Processor 402 may be a single-core or multi-core processor.

[0265] References to "computer-readable storage medium," "computer program product," "tangibly embodied computer program," etc., or "controller," "computer," "processor," etc., should be understood to cover not only computers having different architectures, such as single / multi-processor architectures and sequential (von Neumann) / parallel architectures, but also special-purpose circuits, such as field-programmable gate arrays (FPGAs), application-specific circuits (ASICs), signal processing devices, and other processing circuit systems. References to computer programs, instructions, code, etc., should be understood to cover software or firmware for a programmable processor, such as the programmable content of a hardware device, whether instructions for a processor, or configuration settings for a fixed-function device, gate array, or programmable logic device, etc.

[0266] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0267] (a) hardware circuitry implementation only (such as implementation in analog and / or digital circuitry only) and

[0268] (b) a combination of hardware circuitry and software such as (where applicable):

[0269] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0270] (ii) any portion of hardware processor(s) (including digital signal processor(s)), software and memory(s) with software that work together to enable a device such as a mobile phone or server to perform various functions, and

[0271] (c) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), that require software (e.g., firmware) to operate, but where software is not required for operation, the software may not be present.

[0272] This definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor and its accompanying software and / or firmware. For example, the term circuitry also covers a baseband integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, if applicable to the particular claim element.

[0273] The blocks shown in the figures may represent steps in a method and / or code segments in a computer program 406. The illustration of a particular order of blocks does not necessarily represent a required or preferred order for the blocks, and the order and arrangement of the blocks may vary. In addition, some blocks may be omitted.

[0274] Where a structural feature has been described, it may be replaced by a means for performing one or more of the functions of the structural feature, whether that function or functions is explicitly or implicitly described.

[0275] As used herein, "module" refers to a unit or device that does not include certain parts / components added by the final manufacturer or user. A controller may be a module.

[0276] The above example finds the application as an enabling component for:

[0277] Automotive systems; telecommunications systems; electronic systems, including consumer electronics; distributed computing systems; media systems for generating or rendering media content, including audio, visual and audiovisual content and mixed, mediated, virtual and / or augmented reality; personal systems, including personal health systems or personal fitness systems; navigation systems; user interfaces, also known as human-machine interfaces; networks, including cellular, non-cellular and optical networks; ad hoc networks; the Internet; the Internet of Things; virtualized networks; and related software and services.

[0278] According to the examples of the present disclosure, the device can be set in an electronic device, for example, a mobile terminal. However, it should be understood that the mobile terminal is only an example of an electronic device that will benefit from the implementation of the present disclosure, and therefore, it should not be considered to limit the scope of the present disclosure to this. Although in some implementation examples, the device can be set in a mobile terminal, other types of electronic devices, such as but not limited to: mobile communication devices, handheld portable electronic devices, wearable computing devices, portable digital assistants (PDAs), pagers, mobile computers, desktop computers, televisions, gaming devices, laptop computers, cameras, video recorders, GPS devices, and other types of electronic systems can easily adopt the examples of the present disclosure. In addition, the device can easily adopt the examples of the present disclosure, regardless of its intention to provide mobility.

[0279] The term "comprise" as used in this document is inclusive rather than exclusive. That is, any reference to X including Y indicates that X may include only one Y or may include more than one Y. If the exclusive meaning of "comprise" is intended, it will be made clear in the context by reference to "comprising only one" or by the use of "consisting".

[0280] In this specification, "connected", "coupled" and "in communication" and their derivatives refer to being operationally connected / coupled / in communication. It should be understood that any number or combination of intermediate components (including no intermediate components) may be present, i.e., to provide direct or indirect connection / coupling / in communication. Any such intermediate components may include hardware and / or software components.

[0281] As used herein, the term "determine / determining" (and grammatical variations thereof) may include at least: calculating, computing, processing, deriving, measuring, investigating, identifying, searching (e.g., searching in a table, a database, or another data structure), confirming, etc. In addition, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), obtaining, etc. In addition, "determine / determining" may include resolving, selecting, choosing, establishing, etc.

[0282] In this specification, reference has been made to various examples. The description of features or functions associated with an example indicates that these features or functions are present in the example. The use of the term "example" or "for example" or "may" or "can" in the text indicates (whether explicitly stated or not) that such features or functions are present in at least the example described, whether described as an example or not, and they may but not necessarily be present in some or all other examples. Therefore, "example" or "for example" or "may" or "can" refers to a specific instance in a class of examples. The attributes of an instance may be attributes of only that instance or attributes of a class or attributes of a subclass of a class including some but not all instances in the class. Therefore, it is implicitly disclosed that features described with reference to one example rather than with reference to another example may be used as part of a working combination in the other example where possible, but do not necessarily have to be used in the other example.

[0283] Although the examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

[0284] Features described in the preceding description may be used in other combinations than the combinations explicitly described above.

[0285] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0286] Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

[0287] The terms "a", "an", or "the" as used in this document are inclusive and not exclusive. That is, any reference to X that includes an a / an / the Y indicates that X may include only one Y or may include more than one Y, unless the context clearly indicates otherwise. If "a", "an", or "the" is intended to be used in an exclusive sense, this will be clearly stated in the context. In some cases, "at least one" or "one or more" may be used to emphasize the inclusive meaning, but the absence of these terms should not be regarded as inferring any exclusive meaning.

[0288] The presence of a feature (or combination of features) in a claim is a reference to the feature or (combination of features) itself, as well as a reference to features that achieve substantially the same technical effect (equivalent features). Equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. Equivalent features include, for example, features that perform substantially the same function in substantially the same way to achieve substantially the same result.

[0289] In this specification, reference has been made to various examples using adjectives or adjective phrases to describe features of examples. Such description of a characteristic associated with an example indicates that the characteristic exists in some examples exactly as described, and exists in other examples substantially as described.

[0290] The above description describes some examples of the present disclosure, however, those skilled in the art will be aware of possible alternative structures and method features that provide equivalent functions to the specific examples of such structures and features described above, and for the sake of brevity and clarity, these alternative structures and features have been omitted in the above description. Nevertheless, the above description should be understood to implicitly include references to such alternative structures and method features that provide equivalent functions, unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

[0291] While efforts have been made in the foregoing description to draw attention to those features regarded as important, it should be understood that the applicant may seek protection by way of claims for any patentable feature or combination of features mentioned above and / or shown in the drawings, whether or not emphasis has been placed thereon.

Claims

1. A user equipment, comprising: means for receiving, from a network node, an indication to disable hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure; as well as Means for disabling hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure based on the received indication.

2. The user equipment according to claim 1, wherein the indication indicates disabling, or provides conditions for the UE to determine disabling.

3. The user equipment according to claim 1 or 2, wherein the indication comprises: Received broadcast system information.

4. The user equipment of claim 3, wherein the broadcast system information defines one or more coverage enhancement levels, wherein at least one coverage enhancement level is associated with disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure.

5. The user equipment according to claim 3 or 4, wherein the broadcast system information defines one or more thresholds for evaluating downlink signals at the user equipment.

6. The user equipment according to claim 1 or 2, wherein the indication is a modified downlink random access response in the contention-based random access procedure.

7. The user equipment according to claim 1 or 2, wherein the indication is downlink control information including a modified HARQ-ACK resource field.

8. The user equipment according to claim 1, 2 or 7, wherein the modification of the downlink control information field is indicated in the broadcast system information or is predefined in the specification.

9. The user equipment according to any one of claims 1 to 8, comprising: Means for disabling hybrid automatic request (HARQ) feedback for downlink data messages following the contention resolution message based on the received indication.

10. A user equipment according to any one of the preceding claims, comprising: Parts for: A disabled capability is indicated to a network node, the disabling being disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure.

11. The user equipment according to claim 10, comprising: Means for indicating the disabled capability to a network node using an uplink message of the contention based random access procedure.

12. The user equipment according to claim 10 or 11, wherein the means for indicating to the network a disabled capability at the user equipment for hybrid automatic request (HARQ) feedback of at least a downlink contention resolution message in a contention-based random access procedure comprises: means for implicitly indicating said capability by constraining detectable characteristics of random access requests in said contention-based random access procedure.

13. The user equipment according to claim 10, 11 or 12, wherein the means for indicating to the network a disabled capability at the user equipment for hybrid automatic request (HARQ) feedback of at least downlink contention resolution messages in a contention-based random access procedure comprises: Means for implicitly indicating said capability by selecting between different configurations for said random access request in said contention based random access procedure, wherein a first set of configurations indicates capability and a second set of configurations indicates lack of capability.

14. The user equipment according to any one of claims 12 or 13, wherein: The means for implicitly indicating the capability comprises: means for selecting a preamble for the random access request from a first predefined subset to use to indicate a first capability, and means for selecting a preamble for the random access request from a second predefined subset to indicate a second capability, and / or The means for implicitly indicating the capability comprises: means for selecting subcarriers for the random access request from a first predefined subset to use to indicate a first capability, and means for selecting subcarriers for the random access request from a second predefined subset to indicate a second capability, and / or The means for implicitly indicating the capability comprises means for selecting time domain resources for the random access request from a first predefined subset to use to indicate a first capability, and means for selecting time domain resources for the random access request from a second predefined subset to indicate a second capability.

15. The user equipment according to any one of claims 10 to 14, wherein the means for indicating to the network a disabled capability at the user equipment for hybrid automatic request (HARQ) feedback of at least downlink contention resolution messages in a contention-based random access procedure comprises: means for explicitly indicating said capability by adapting scheduled UL transmissions in said contention based random access procedure.

16. A user equipment according to any preceding claim, comprising: A component for performing a contention-based random access procedure, the contention-based random access procedure comprising: Sending a random access request; receiving a random access response; Sending scheduled UL transmission; receiving contention resolution messages; And the user equipment comprises: a component for determining from the downlink control information that the next sent contention resolution message is the last sent contention resolution message and there is no subsequent retransmission of the contention resolution message.

17. The user equipment according to claim 16, comprising: means for stopping a contention resolution timer in response to determining from said downlink control information that said next transmitted contention resolution message is a last transmitted contention resolution message.

18. A method comprising: receiving an indication from a network node to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; as well as According to the received indication, hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message is disabled in a contention-based random access procedure.

19. A computer program comprising instructions which, when executed on a device, enable the device to control: receiving an indication to disable hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure; and According to the received indication, hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message is disabled in a contention-based random access procedure.

20. A network node comprising means for: Disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure is indicated to at least the user equipment.

21. The network node of claim 20, wherein the means for indicating disabling of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure at the user equipment comprises means for: Indicates that it is disabled, or Provides conditions for the UE to determine disabling.

22. The network node according to claim 20 or 21, wherein the means for indicating disabling of hybrid automatic request (HARQ) feedback for downlink contention resolution message in a contention-based random access procedure at the user equipment comprises means for: Broadcasts a system message to indicate disabling.

23. The network node of claim 22, wherein the system information is included in a broadcast system information block.

24. The network node according to claim 22 or 23, wherein the system information defines one or more coverage enhancement levels, wherein at least one coverage enhancement level is associated with disabling of hybrid automatic request (HARQ) feedback for at least downlink contention resolution message in a contention-based random access procedure at the user equipment.

25. A network node according to claim 22, 23 or 24, wherein the system information defines one or more thresholds for assessing signal quality at the user equipment.

26. The network node according to any one of claims 20 to 25, wherein the means for indicating disabling of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure at the user equipment comprises means for: A downlink random access response is modified in the contention-based random access procedure to indicate disabling.

27. The network node according to any one of claims 20 to 26, wherein the means for indicating disabling of hybrid automatic request (HARQ) feedback for downlink contention resolution messages in a contention-based random access procedure at the user equipment comprises means for: The disabling is indicated using downlink control information.

28. The network node according to any one of claims 20 to 27, comprising: A component for modifying a HARQ-ACK resource field in downlink control information to indicate a disabled component.

29. The network node according to any one of claims 20 to 28, comprising: A component for performing a contention-based random access procedure on the user equipment, the contention-based random access procedure comprising: receiving a random access request from the user equipment; Sending a random access response to the user equipment; receiving a scheduled uplink transmission from the user equipment; sending a contention resolution to the user equipment; And the network node comprises: means for notifying the user equipment in downlink control information that the next contention resolution message is the last contention resolution message and there is no subsequent retransmission of the contention resolution message.

30. The network node according to any one of claims 20 to 29, The indication of disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least a downlink contention resolution message in a contention-based random access procedure to at least a user equipment also indicates disabling at the user equipment of hybrid automatic request (HARQ) feedback for a downlink message transmitted after the downlink contention resolution message.

31. The network node according to any one of claims 20 to 30, wherein the network node is a transmission reception point.

32. The network node according to any one of claims 20 to 31, comprising: Means for receiving, from a user equipment, an indication of a capability for disabling at the user equipment of hybrid automatic request (HARQ) feedback for at least downlink contention resolution messages in a contention-based random access procedure.

33. The network node according to claim 32, comprising: Means for receiving an indication of said capability in an uplink message of said contention based random access procedure.

34. The network node according to claim 33, comprising: Means for implicitly receiving an indication of said capability via a restricted detectable feature of a random access request in said contention-based random access procedure.

35. The network node according to claim 33, comprising: means for receiving the indication of the capability via a preamble for the random access request, wherein the preamble is selected from a first predefined subset to indicate a first capability and from a second predefined subset to indicate a lack of capability, and / or means for receiving an indication of the capability via subcarriers for the random access request, wherein the subcarriers are selected from a first predefined subset to indicate a first capability and from a second predefined subset to indicate a lack of capability, and / or Means for receiving the indication of the capability via a time domain resource for the random access request, wherein the time domain resource is selected from a first predefined subset to indicate a first capability and from a second predefined subset to indicate a lack of capability.

36. The network node according to any one of claims 20 to 35, comprising: Means for receiving an indication of the capability via a scheduled uplink transmission in the contention-based random access procedure.

37. A method comprising: Disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure is indicated to at least the user equipment.

38. A computer program comprising instructions which, when executed on a device, enable the device to control: Disabling of hybrid automatic request (HARQ) feedback at the user equipment for at least a downlink contention resolution message in a contention-based random access procedure is indicated to at least the user equipment.

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