SYSTEMS AND METHODS FOR ENABLING OR DISABLING HARQ FEEDBACK

Presented are systems and methods for enabling or disabling hybrid automatic repeat request (HARQ) feedback. A wireless communication device (e.g., UE) may determine a transmission setting for coverage enhancement (CE). The wireless communication device may determine whether to disable at least one HARQ process according to the transmission setting for CE.

TECHNICAL FIELD

The disclosure relates generally to wireless communications, including but not limited to systems and methods for enabling or disabling HARQ feedback.

BACKGROUND

The standardization organization Third Generation Partnership Project (3GPP) is currently in the process of specifying a new Radio Interface called 5G New Radio (5G NR) as well as a Next Generation Packet Core Network (NG-CN or NGC). The 5G NR will have three main components: a 5G Access Network (5G-AN), a 5G Core Network (5GC), and a User Equipment (UE). In order to facilitate the enablement of different data services and requirements, the elements of the 5GC, also called Network Functions, have been simplified with some of them being software based, and some being hardware based, so that they could be adapted according to need.

SUMMARY

At least one aspect is directed to a system, method, apparatus, or a computer-readable medium of the following. A wireless communication device (e.g., UE) may determine a transmission setting for coverage enhancement (CE). The wireless communication device may determine whether to disable at least one hybrid automatic repeat request (HARQ) process according to the transmission setting for CE.

In some embodiments, the wireless communication device may determine at least one criterion for CE. The wireless communication device may determine to disable the at least one HARQ process, when the transmission setting for CE is lower than the at least one criterion for CE. The wireless communication device may determine to enable the at least one HARQ process, when the transmission setting for CE is higher than, equal to, or satisfying the at least one criterion for CE. In some embodiments, the wireless communication device may determine at least one criterion for CE. The wireless communication device may determine to disable the at least one HARQ process, when the transmission setting for CE is lower than, equal to, or satisfying the at least one criterion for CE. The wireless communication device may determine to enable the at least one HARQ process, when the transmission setting for CE is higher than the at least one criterion for CE.

In some embodiments, the wireless communication device may determine, using a mapping configuration for a plurality of candidate transmission settings, to enable or disable the at least one HARQ process according to the transmission setting for CE. In certain embodiments, the wireless communication device may receive a mapping configuration of candidate transmission settings, via a radio resource control (RRC) signaling, or a system information block (SIB) signaling from a wireless communication node (e.g., a ground terminal, a base station, a gNB, an eNB, a repeater, or a serving node). The wireless communication device may determine, using the mapping configuration, whether to disable a first HARQ process of the at least one HARQ process, according to the transmission setting for CE.

In some embodiments, the wireless communication device may determine to disable the at least one HARQ process when the transmission setting for CE comprises a first type, and may determine to enable the at least one HARQ process when the transmission setting for CE does not comprise the first type. The wireless communication device may determine to enable the at least one HARQ process when the transmission setting for CE comprises the first type, and may determine to disable the at least one HARQ process when the transmission setting for CE does not comprise the first type. In some embodiments, the wireless communication device may determine to enable the at least one HARQ process when the transmission setting for CE comprises a first type. The wireless communication device may determine to disable the at least one HARQ process when the transmission setting for CE comprises a second type.

In some embodiments, the transmission setting for CE may comprise one of CE level 0, CE level 1, CE level 2, or CE level 3. The transmission setting for CE may comprise one of CEModeA or CEModeB.

In some embodiments, the wireless communication device may receive at least one criterion via a radio resource control (RRC) signaling, or a system information block (SIB) signaling from a wireless communication node. The wireless communication device may determine to disable a first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being lower than the at least one criterion. The wireless communication device may determine to enable the first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being higher than, equal to, or satisfying the at least one criterion. In some embodiments, the wireless communication device may determine to disable a first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being lower than, equal to, or satisfying the at least one criterion. The wireless communication device may determine to enable the first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being higher than the at least one criterion.

In some embodiments, the wireless communication device may determine whether to disable the at least one HARQ process according to at least one of: (i) the transmission setting of CE, (ii) a signaling from a wireless communication node, or (iii) a priority between using the transmission setting of CE and the signaling from the wireless communication node. The wireless communication device may determine whether to disable the at least one HARQ process according to (i) the transmission setting of CE, or (ii) the signaling from the wireless communication node, based on a predefined configuration. The wireless communication device may determine that there is a conflict on whether to disable the at least one HARQ process, between (i) the transmission setting of CE, and (ii) the signaling from the wireless communication node. The wireless communication device may resolving the conflict according to the priority.

DETAILED DESCRIPTION

1. Mobile Communication Technology and Environment

FIG.1illustrates an example wireless communication network, and/or system,100in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure. In the following discussion, the wireless communication network100may be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is herein referred to as “network100.” Such an example network100includes a base station102(hereinafter “BS102”; also referred to as wireless communication node) and a user equipment device104(hereinafter “UE104”; also referred to as wireless communication device) that can communicate with each other via a communication link110(e.g., a wireless communication channel), and a cluster of cells126,130,132,134,136,138and140overlaying a geographical area101. InFIG.1, the BS102and UE104are contained within a respective geographic boundary of cell126. Each of the other cells130,132,134,136,138and140may include at least one base station operating at its allocated bandwidth to provide adequate radio coverage to its intended users.

For example, the BS102may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE104. The BS102and the UE104may communicate via a downlink radio frame118, and an uplink radio frame124respectively. Each radio frame118/124may be further divided into sub-frames120/127which may include data symbols122/128. In the present disclosure, the BS102and UE104are described herein as non-limiting examples of “communication nodes,” generally, which can practice the methods disclosed herein. Such communication nodes may be capable of wireless and/or wired communications, in accordance with various embodiments of the present solution.

FIG.2illustrates a block diagram of an example wireless communication system200for transmitting and receiving wireless communication signals (e.g., OFDM/OFDMA signals) in accordance with some embodiments of the present solution. The system200may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, system200can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment100ofFIG.1, as described above.

System200generally includes a base station202(hereinafter “BS202”) and a user equipment device204(hereinafter “UE204”). The BS202includes a BS (base station) transceiver module210, a BS antenna212, a BS processor module214, a BS memory module216, and a network communication module218, each module being coupled and interconnected with one another as necessary via a data communication bus220. The UE204includes a UE (user equipment) transceiver module230, a UE antenna232, a UE memory module234, and a UE processor module236, each module being coupled and interconnected with one another as necessary via a data communication bus240. The BS202communicates with the UE204via a communication channel250, which can be any wireless channel or other medium suitable for transmission of data as described herein.

In accordance with some embodiments, the UE transceiver230may be referred to herein as an “uplink” transceiver230that includes a radio frequency (RF) transmitter and a RF receiver each comprising circuitry that is coupled to the antenna232. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, in accordance with some embodiments, the BS transceiver210may be referred to herein as a “downlink” transceiver210that includes a RF transmitter and a RF receiver each comprising circuity that is coupled to the antenna212. A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna212in time duplex fashion. The operations of the two transceiver modules210and230may be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna232for reception of transmissions over the wireless transmission link250at the same time that the downlink transmitter is coupled to the downlink antenna212. Conversely, the operations of the two transceivers210and230may be coordinated in time such that the downlink receiver is coupled to the downlink antenna212for reception of transmissions over the wireless transmission link250at the same time that the uplink transmitter is coupled to the uplink antenna232. In some embodiments, there is close time synchronization with a minimal guard time between changes in duplex direction.

The UE transceiver230and the base station transceiver210are configured to communicate via the wireless data communication link250, and cooperate with a suitably configured RF antenna arrangement212/232that can support a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver210and the base station transceiver210are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the present disclosure is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver230and the base station transceiver210may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof.

The network communication module218generally represents the hardware, software, firmware, processing logic, and/or other components of the base station202that enable bi-directional communication between base station transceiver210and other network components and communication nodes configured to communication with the base station202. For example, network communication module218may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module218provides an 802.3 Ethernet interface such that base station transceiver210can communicate with a conventional Ethernet based computer network. In this manner, the network communication module218may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC)). The terms “configured for,” “configured to” and conjugations thereof, as used herein with respect to a specified operation or function, refer to a device, component, circuit, structure, machine, signal, etc., that is physically constructed, programmed, formatted and/or arranged to perform the specified operation or function.

The Open Systems Interconnection (OSI) Model (referred to herein as, “open system interconnection model”) is a conceptual and logical layout that defines network communication used by systems (e.g., wireless communication device, wireless communication node) open to interconnection and communication with other systems. The model is broken into seven subcomponents, or layers, each of which represents a conceptual collection of services provided to the layers above and below it. The OSI Model also defines a logical network and effectively describes computer packet transfer by using different layer protocols. The OSI Model may also be referred to as the seven-layer OSI Model or the seven-layer model. In some embodiments, a first layer may be a physical layer. In some embodiments, a second layer may be a Medium Access Control (MAC) layer. In some embodiments, a third layer may be a Radio Link Control (RLC) layer. In some embodiments, a fourth layer may be a Packet Data Convergence Protocol (PDCP) layer. In some embodiments, a fifth layer may be a Radio Resource Control (RRC) layer. In some embodiments, a sixth layer may be a Non Access Stratum (NAS) layer or an Internet Protocol (IP) layer, and the seventh layer being the other layer.

2. Systems and Methods for HARQ Feedback Enabling-Disabling Configuration

In a system configured with a hybrid automatic repeat request (HARQ) mechanism, a HARQ process can perform a retransmission after receiving feedback. When a propagation delay is long, e.g., in a non-terrestrial network (NTN), the HARQ process can wait a long time for the feedback (e.g., acknowledgement/response regarding receipt/non-receipt of transmission) before the next transmission. If all of the HARQ processes have completed a transmission but none of the feedback is received due to large round trip time (RTT), a transmitter may stop transmitting and HARQ stalling may occur. For example, in a terrestrial network (TN), RTT can be tens or hundreds of microseconds, which may be negligible compared to scheduling delay and transmission duration. However, in NTN, RTT can be as long as several hundreds of milliseconds, which can be longer than the transmission duration of one TB. In some embodiments, if two HARQ processes are supported, a new transmission scheduling for a first HARQ process cannot be received before a second HARQ process completes its transmission due to large propagation delay of HARQ feedback. As a result, a time interval between the completion time of transmission of the second HARQ process and the start time of the new transmission of the first HARQ process may be wasted (e.g., idle) due to no transmission, i.e., HARQ stalling. In order to avoid the HARQ stalling and to increase throughput, HARQ feedback disabling (e.g., disabling of a portion of the HARQ process that is associated with waiting for the feedback and/or processing of the feedback) can be applied.

However, HARQ feedback disabling can be selective. In order to enhance coverage and increase the detection performance, repetition can be applied for data transmission in Narrowband-Internet of Things (NB-IoT) or enhanced Machine Type Communication (eMTC) over the NTN.

If coverage enhancement (CE) level is high (e.g., more repetitions can be applied to mitigate propagation loss), a transmission duration for one transmission may be longer than the RTT. The HARQ stalling may be less probable even if the RTT may be long, and the HARQ feedback can be enabled to improve detection performance. Otherwise, HARQ feedback can be disabled to improve throughput. The enabling/disabling of HARQ feedback can be configured according to the coverage enhancement level. In certain embodiments, a channel condition can be stable in IoT-NTN since the UEs are mostly static/stationary in position/location. In this disclosure, a semi-static configuration for enabling/disabling of HARQ feedback is discussed, which can be simple and can reduce signaling overhead.

FIG.3illustrates an example structure of a transparent NTN, in accordance with some embodiments of the present disclosure. A link between a UE (e.g., a user equipment, the UE104, the UE204, a mobile device, a wireless communication device, a terminal, etc.) and a satellite can be a service link. A link between a BS (e.g., a base station, the BS102, the BS202, a gNB, an eNB, a wireless communication node, etc.) and a satellite can be a feeder link and can be common for all UEs within the same cell. Due to high altitude of the satellite, a propagation delay can be large. For an NTN, especially with the aerial vehicular entity in geosynchronous equatorial orbit (GEO), the RTT between the UE and the BS can be as long as several hundreds of milliseconds due to long (signal transmission/propagation) distance(s). In low earth orbit (LEO), the RTT between the UE and the BS can be a few milliseconds to tens of milliseconds.

In enhanced Machine Type Communication (eMTC) and Narrowband-Internet of Things (NB-IoT), repetition transmission can be applied to enhance the coverage. For example, a physical downlink shared channel (PDSCH) can be configured to be transmitted128times to let/allow/enable a UE to combine the repetition/repeated transmissions in detection. When a repetition number of the repetition/repeated transmission is large enough, the receiver can be able to decode a message at very low signal-to-noise ratio (SNR) (e.g., high path loss caused by larger coverage range can be mitigated).

Different types of transmission settings can be supported to serve different scenarios. In order to handle/manage/manipulate different scenarios, multiple CE levels (e.g., transmission settings) can be defined in NB-IoT and/or eMTC. In NB-IoT, there can be three types of CE levels, including CE level 0 (e.g., small number of repetitions), CE level 1, and CE level 2 (e.g., large number of repetitions). The multiple CE levels (e.g., CE level 0, CE level 1, and CE level 2) can handle scenarios where a maximum coupling loss (MCL) equals to 144 dB, 154 dB, and 164 dB (e.g., a higher MCL may indicate that a channel attenuation can be worse), respectively. In eMTC, there can be four types of CE levels, including CE level 0, CE level 1, CE level 2, and CE level 3. The multiple CE levels can be defined for idle mode/state (e.g., IDLE mode). In some embodiments, there can be two types of CE modes, including CEmodeA (e.g., small number of repetitions) and CEmodeB (e.g., large number of repetitions). The multiple CE modes can be defined for connected mode/state (e.g., RRC_CONNECTED mode). With different CE levels or CE modes, a UE and a BS may choose different repetition numbers to mitigate channel loss/attenuation.

FIG.4illustrates representations of HARQ stalling and HARQ feedback disabling, in accordance with some embodiments of the present disclosure. HARQ stalling with a long RTT (e.g., a low CE level) is shown in (1) ofFIG.4. The HARQ feedback disabling can be implemented at least for new radio (NR)-NTN. By disabling the HARQ feedback of one HARQ process, the UE can continuously transmit new transport blocks (TBs) without performing a stop and wait procedure as shown in (2) ofFIG.4. As a result, the HARQ stalling due to a large RTT can be avoided and throughput can be increased. However, detection performance can decrease at a same time when there is no HARQ retransmission. Hence, HARQ feedback disabling can be configured in NR-NTN to make a tradeoff between throughput and detection performance.

Repetition can be applied in data transmission (e.g., in IoT-NTN or eMTC) to improve the detection performance at a receiver. If a repetition number (of data transmission) is large enough, a duration of transmitting one TB may be longer than the RTT. In such a case (e.g., a high CE level), the HARQ stalling may be less probable even if HARQ feedback is enabled as shown in (3) ofFIG.4. The disabling configuration can be associated with parameters related to transmission duration, e.g., the repetition number and scheduling delay.

IMPLEMENTATION EXAMPLE 1

A coverage enhancement (CE) level and/or CE mode can impact a selection of repetition number in the transmission in NB-IoT and eMTC. With a larger repetition number, a transmission duration of a single transmission block (TB) can be longer and HARQ stalling may be less probable. For a high CE level (e.g., a repetition number is large and HARQ stalling is less probable), a HARQ feedback can be enabled to improve a reliability and/or throughput of transmission. For a low CE level (e.g., a HARQ stalling is more probable), the HARQ feedback can be disabled to improve the reliability and/or throughput of transmission. In some embodiments, similar procedures can be used as described with respect to a single HARQ process.

In some embodiments, there can be two ways to determine a CE level or a CE mode. The UE may determine the CE level or the CE mode based on a reference signal receiving power (RSRP) measurement for instance. In certain embodiments, the network may configure/specify/indicate/set a CE level or CE mode to apply. The UE may use the configured, by the network, CE level or CE mode for initial access regardless of the RSRP measurement.

In some embodiments, the UE may determine whether to disable at least one HARQ process according to (e.g., by comparing) a CE level/mode criterion. The CE level/mode criterion can be predefined (e.g., a predefined threshold/criterion) or configured (e.g., determined, calculated, computed) by a BS (e.g., the UE receiving a threshold/criterion from the BS). The criterion may include a threshold value/index, or a certain coverage enhancement requirement/level/scenario. For example, a HARQ feedback can be disabled if the applied/determined/configured CE level/mode index is lower than a threshold value/index, and the HARQ feedback can be enabled if the applied/determined/configured CE level/mode index is higher than, equal to, and/or satisfying the threshold value/index. In certain embodiments, the HARQ feedback can be disabled if the applied/determined/configured CE level/mode index is lower than, equal to, and/or satisfying the threshold value/index, and the HARQ feedback can be enabled if the applied/determined/configured CE level/mode index is higher than the threshold value/index. In certain embodiments, a HARQ feedback can be disabled if the applied/determined/configured CE level/mode is lower than a certain coverage enhancement requirement/level/scenario, and the HARQ feedback can be enabled if the applied/determined/configured CE level/mode is higher than, equal to, and/or satisfying the certain coverage enhancement requirement/level/scenario. In certain embodiments, the HARQ feedback can be disabled if the applied/determined/configured CE level/mode is lower than, equal to, and/or satisfying the certain coverage enhancement requirement/level/scenario, and the HARQ feedback can be enabled if the applied/determined/configured CE level/mode is higher than the certain coverage enhancement requirement/level/scenario. In some embodiments, more threshold values/indexes can be configured to indicate more disabling patterns (e.g., configurations or mapping relationships between threshold values/indexes and corresponding enabling/disabling operations/states).

In some embodiments, the UE may determine whether to disable at least one HARQ process according to a mapping pattern/configuration between CE levels and enabling/disabling operations/states. The mapping pattern/configuration between CE levels and enabling/disabling operations/states can be predefined (e.g., a predefined mapping pattern/configuration) or configured/indicated by a BS (e.g., the UE receiving a mapping pattern/configuration from the BS). For example, the mapping pattern/configuration can be listed/specified in a table (e.g., CE level 0 is to disable, CE level 1 is to enable, and CE level 2 is to enable HARQ-ACK response/process). In some embodiments, any mapping patterns/configurations can be possible. The HARQ feedback can be disabled if the applied/determined/configured CE level corresponds to a disabling operation/state/mode in the mapping pattern/configuration. In certain embodiments, the HARQ feedback can be enabled if the applied/determined/configured CE level corresponds to an enabling operation/state/mode in the mapping pattern/configuration.

In some embodiments, the UE may determine whether to disable at least one HARQ process according to a mapping pattern/configuration between CE modes (e.g., CEmodeA or CEmodeB) and enabling/disabling operation/state/mode. The mapping pattern/configuration between CE modes and enabling/disabling operation/state/mode can be predefined or configured by a BS. In some embodiments, when a UE is in CEmodeA (e.g., small number of repetition), the HARQ feedback can be disabled. Repetition can still be applied for data transmission. When the UE is in CEmodeB, the HARQ feedback can be enabled. In some embodiments, the HARQ feedback can be disabled if the applied/determined/configured CE mode corresponds to a disabling operation/state/mode in the mapping pattern/configuration. Otherwise, the HARQ feedback can be enabled.

IMPLEMENTATION EXAMPLE 2

If threshold values/indexes or mapping patterns/configurations is to be configured by BS, the threshold values/indexes or mapping patterns/configurations can be indicated via a system information block (SIB) broadcast or a radio resource control (RRC) signaling (e.g., a dedicated RRC signaling). The BS may indicate threshold values/indexes or mapping patterns/configurations to the UE in a SIB signaling or a RRC signaling. In some embodiments, the wireless communication device may receive from the wireless communication node, the at least one criterion via a RRC or SIB signaling.

A configuration (e.g., threshold values/indexes or mapping patterns/configurations) may be common to all UEs or a group of UEs within a cell. In such a case, the threshold values/indexes or mapping patterns/configurations can be broadcast/sent via a SIB signaling, which may save/reduce the amount of signaling. In some embodiments, the configuration may be per (e.g., specific to a) UE. In such case, the threshold values/indexes or mapping patterns/configurations can be indicated via a dedicated RRC signaling, which may enable flexible configuration (e.g., on a per-UE basis) to improve performance.

In some embodiments, the configuration (e.g., threshold values/indexes or mapping patterns/configurations) may be per (e.g., specific to a) HARQ process (e.g., independent to whether it is per UE or not). Different threshold values/indexes or mapping patterns/configurations can be defined or configured for different HARQ processes. For example, for a UE with two HARQ processes, a BS may configure that a first HARQ process is enabled when a CE level of the UE is higher than or equal to CE level 1, while a second HARQ process can be enabled when a CE level of the UE is equal to CE level 2. In such a case, when HARQ stalling exists but is not very significant, it can be possible to disable only part of the HARQ processes to achieve tradeoff between throughput and error rate.

In some embodiments, the UE may determine to disable a first HARQ process of the at least one HARQ process, responsive to the CE level of the UE being lower than the at least one criterion. The UE may determine to enable the first HARQ process of the at least one HARQ process, responsive to the CE level of the UE being higher than, equal to, or satisfying the at least one criterion. In some embodiments, the UE may determine to disable a first HARQ process of the at least one HARQ process, responsive to the CE level of the UE being lower than, equal to, or satisfying the at least one criterion. The UE may determine to enable the first HARQ process of the at least one HARQ process, responsive to the CE level of the UE being higher than the at least one criterion.

IMPLEMENTATION EXAMPLE 3

In NR-NTN, a BS can directly configure the enabling/disabling of a HARQ feedback per UE per HARQ process (the HARQ feedback may be always configured in a specific way). In IoT-NTN, the CE level/mode based enabling/disabling of HARQ feedback may be adopted along with the direct configuration mechanism from NR-NTN.

When the two mechanisms (e.g., direct configuration by a BS, or HARQ feedback enabling/disabling according to the CE level/mode) are both adopted and lead to different configurations (e.g., a conflict, or contradictory results), one of them can be selected to have higher priority. For example, if there is a conflict on whether to disable the HARQ feedback (e.g., the direct configuration from the BS indicates to disable the HARQ feedback; the determination of a UE according to the CE level/mode indicates to enable the HARQ feedback), the conflict may be resolved according to a priority between using the direct configuration by the BS and the CE level/mode determination of the UE. For example, if the priority of the CE level/mode determination of the UE is high and the CE level/mode determination corresponds to enabling of HARQ feedback for a HARQ process, the HARQ feedback is enabled no matter/regardless of whether the HARQ process is enabled or disabled via the direct configuration from the BS. For another example, if the priority of the CE level/mode determination of the UE is high and the CE level/mode determination corresponds to disabling of HARQ feedback for a HARQ process, the HARQ feedback is disabled no matter/regardless of whether the HARQ process is enabled or disabled via the direct configuration from the BS. For another example, the UE may follow the direct configuration of HARQ feedback from the BS to disable the HARQ feedback no matter/regardless of which CE level/mode is selected. For another example, the UE may follow the direct configuration of HARQ feedback from the BS to enable the HARQ feedback no matter/regardless of which CE level/mode is selected.

In some embodiments, the UE may determine whether to disable the at least one HARQ feedback according to (i) the transmission setting of CE, or (ii) the signaling from the BS, based on a predefined configuration. The predefined configuration may indicate whether (i) or (ii) is always getting higher priority or always used (instead of using the other). For example, if the predefined configuration (e.g., priority) of the transmission setting of CE is high and the transmission setting corresponds to enabling of HARQ feedback for a HARQ process, the HARQ feedback is enabled no matter/regardless of whether the HARQ process is enabled or disabled via the signaling from the BS. For another example (another predefined configuration), the UE may follow the signaling from the BS to disable the HARQ feedback no matter/regardless of which CE level/mode is selected.

FIG.6illustrates a flow diagram of a method600for enabling or disabling HARQ feedback. The method600may be implemented using any one or more of the components and devices detailed herein in conjunction withFIGS.1-5. In overview, the method600may be performed by a wireless communication device (e.g., a UE), in some embodiments. Additional, fewer, or different operations may be performed in the method600depending on the embodiment. At least one aspect of the operations is directed to a system, method, apparatus, or a computer-readable medium.

A wireless communication device (e.g., a UE) may determine a transmission setting for coverage enhancement (CE) (e.g., CE levels 0/1/2/3 or CE Mode A/B) (operation610). The wireless communication device may determine whether to disable/enable at least one hybrid automatic repeat request (HARQ) process according to (e.g., based on, or in response to) the transmission setting for CE (operation620).

In some embodiments, the wireless communication device may determine at least one criterion (e.g., an actual threshold value/index, or a certain coverage enhancement requirement/level/scenario) for CE (e.g., determining/retrieving a predefined threshold value/index, or receiving a threshold value/index configured by and/or sent from a BS). The wireless communication device may determine to disable the at least one HARQ process, when the transmission setting for CE is lower than or not satisfying the at least one criterion (e.g., threshold or condition) for CE. The wireless communication device may determine to enable the at least one HARQ process, when the transmission setting for CE is higher than, equal to, or satisfying the at least one criterion for CE. In some embodiments, the wireless communication device may determine (e.g., access/retrieve/receive) at least one criterion for CE. The wireless communication device may determine to disable the at least one HARQ process, when the transmission setting for CE is lower than, equal to, or satisfying the at least one criterion for CE. The wireless communication device may determine to enable the at least one HARQ process, when the transmission setting for CE is higher than the at least one criterion for CE.

In some embodiments, the wireless communication device may determine, using a mapping configuration/pattern (e.g., a configuration including CE levels 0/1/2/3 or CE Mode A/B (each mapped to a respective/corresponding enabling or disabling action/operation/mode)) for a plurality of candidate transmission settings, to enable or disable the at least one HARQ process according to the transmission setting for CE. In certain embodiments, the wireless communication device may receive a mapping configuration of candidate/potential transmission settings, via a radio resource control (RRC) signaling (e.g., a dedicated RRC signaling), or a system information block (SIB) signaling from a wireless communication node (e.g., a ground terminal, a base station, a gNB, an eNB, a repeater, or a serving node). The wireless communication device may determine, using the mapping configuration, whether to disable (e.g., inactive, block) a first HARQ process (or a part/portion/some) of the at least one HARQ process, according to the transmission setting for CE.

In some embodiments, the wireless communication device may determine to disable the at least one HARQ process when the transmission setting for CE comprises a first type, and to enable the at least one HARQ process when the transmission setting for CE does not comprise the first type. The wireless communication device may determine to enable the at least one HARQ process when the transmission setting for CE comprises the first type, and to disable the at least one HARQ process when the transmission setting for CE does not comprise the first type. In some embodiments, the wireless communication device may determine to enable the at least one HARQ process when the transmission setting for CE comprises a first type. The wireless communication device may determine to disable the at least one HARQ process when the transmission setting for CE comprises a second type.

In some embodiments, the transmission setting for CE may comprise one of CE level 0, CE level 1, CE level 2, or CE level 3. The transmission setting for CE may comprise one of CEModeA or CEModeB.

In some embodiments, the wireless communication device may receive at least one criterion via a radio resource control (RRC) signaling, or a system information block (SIB) signaling from a wireless communication node. The wireless communication device may determine to disable a first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being lower than (and/or not satisfying) the at least one criterion. The wireless communication device may determine to enable the first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being higher than, equal to, and/or satisfying the at least one criterion. In some embodiments, the wireless communication device may determine to disable a first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being lower than, equal to, or satisfying the at least one criterion. The wireless communication device may determine to enable (e.g., activate, resume) the first HARQ process of the at least one HARQ process, responsive to the transmission setting for CE being higher than the at least one criterion.

In some embodiments, the wireless communication device may determine whether to disable the at least one HARQ process according to at least one of: (i) the transmission setting of CE, (ii) a signaling from a wireless communication node, or (iii) a priority between using the transmission setting of CE and the signaling from the wireless communication node. The wireless communication device may determine whether to disable the at least one HARQ process according to (i) the transmission setting of CE, or (ii) the signaling from the wireless communication node, based on a predefined configuration. The predefined configuration may indicate whether (i) or (ii) is always getting higher priority or always used (instead of using the other).

In some embodiments, the wireless communication device may determine that there is a conflict on whether to disable the at least one HARQ process, between (i) the transmission setting of CE, and (ii) the signaling from the wireless communication node. The wireless communication device may resolve the conflict (e.g., if a conflict arises) according to the priority. If no conflict arises, the wireless communication device may determine whether to disable the at least one HARQ process according to both (i) the transmission setting of CE, and (ii) the signaling from the wireless communication node, arriving at (or resulting in) the same determination/result.

Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.