Methods and apparatus for determining uplink feedback performed by user equipment in response to MTCH transmissions

Abstract

This disclosure describes a method, system, and apparatus for determining whether a user equipment (UE) is performing Multimedia Broadcast Multicast (MBMS) uplink feedback. The method includes at least one UE receiving a multicast traffic channel (MTCH) transmission in an MBMS service from a radio access network (RAN). The method further includes the UE determining to perform MBMS uplink feedback in response to determining that its channel quality indicator (CQI) meets preset conditions.

Description

Technical Field

[0001] This disclosure generally relates to wireless communications. In particular, this disclosure relates to methods and apparatus for determining uplink feedback performed by a user equipment (UE) in response to multicast traffic channel (MTCH) transmissions. Background Technology

[0002] Wireless communication technologies are propelling the world towards an increasingly interconnected and networked society. High-speed and low-latency wireless communication relies on efficient network resource management and allocation between user equipment (UE) and radio access network nodes (including, but not limited to, radio access networks (RAN)). The RAN can communicate with one or more UEs in Multimedia Broadcast Multicast (MBMS) services. This disclosure addresses the challenging and / or problem of determining whether a UE needs to perform uplink feedback for Multicast Traffic Channel (MTCH) transmissions. Summary of the Invention

[0003] This document relates to methods, systems, and apparatus for wireless communication, and more specifically for determining whether a user equipment (UE) performs uplink feedback for multicast traffic channel (MTCH) transmissions.

[0004] In one embodiment, this disclosure describes a method for wireless communication. The method includes determining that a user equipment (UE) is performing Multimedia Broadcast Multicast (MBMS) uplink feedback by: at least one UE receiving multicast traffic channel (MTCH) transmissions in MBMS service from a radio access network (RAN); and the UE determining to perform MBMS uplink feedback in response to determining that the UE's channel quality indicator (CQI) meets preset conditions.

[0005] In another embodiment, this disclosure describes a method for wireless communication. The method includes determining that a user equipment (UE) is performing Multimedia Broadcast Multicast (MBMS) uplink feedback by: at least one UE receiving multicast traffic channel (MTCH) transmissions in MBMS service from a radio access network (RAN); and, in response to determining that a preset uplink feedback condition is met, the UE determines to perform MBMS uplink feedback.

[0006] In another embodiment, this disclosure describes a method for wireless communication. The method includes determining that a user equipment (UE) is performing Multimedia Broadcast Multicast (MBMS) uplink feedback by: at least one UE receiving multicast traffic channel (MTCH) transmissions in MBMS service from a radio access network (RAN); and the UE determining to perform MBMS uplink feedback in response to a first value in signaling received by the UE.

[0007] In another embodiment, this disclosure describes a method for wireless communication. The method includes determining that a user equipment (UE) is performing Multimedia Broadcast Multicast (MBMS) uplink feedback by: at least one UE receiving multicast traffic channel (MTCH) transmissions in MBMS service from a radio access network (RAN); and in response to determining that uplink feedback channel resources for MBMS uplink feedback are configured by the RAN, the UE determines to perform MBMS uplink feedback.

[0008] In some other embodiments, an apparatus for wireless communication may include a memory storing instructions and a processing circuitry system communicating with the memory. When the processing circuitry system executes the instructions, the processing circuitry system is configured to perform the methods described above.

[0009] In some other embodiments, a device for wireless communication may include a memory storing instructions and a processing circuitry system communicating with the memory. When the processing circuitry system executes the instructions, the processing circuitry system is configured to perform the methods described above.

[0010] In some other embodiments, a computer-readable medium includes instructions that, when executed by a computer, cause the computer to perform the methods described above.

[0011] The above and other aspects, and their implementations, are described in more detail in the drawings, description and claims. Attached Figure Description

[0012] Figure 1A An example of point-to-point communication in a wireless communication system is shown.

[0013] Figure 1B An example of multicast communication in a wireless communication system is shown.

[0014] Figure 2 An example of a wireless network node is shown.

[0015] Figure 3 An example of a user device is shown.

[0016] Figure 4 A flowchart of a method for wireless communication is shown.

[0017] Figure 5 A flowchart of a method for wireless communication is shown.

[0018] Figure 6 A flowchart of a method for wireless communication is shown.

[0019] Figure 7 A flowchart of a method for wireless communication is shown. Detailed Implementation

[0020] The present disclosure will now be described in detail below with reference to the accompanying drawings, which form a part of the disclosure and illustrate specific examples of embodiments by way of illustration. However, it should be noted that the present disclosure may be embodied in various different forms, and therefore the subject matter covered or claimed is intended to be construed as not being limited to any of the embodiments set forth below.

[0021] Throughout the specification and claims, terms may have meanings beyond those explicitly stated, implied or suggested by the context. Similarly, the phrases “in one embodiment” or “in some embodiments” as used herein do not necessarily refer to the same embodiment, and the phrases “in another embodiment” or “in other embodiments” as used herein do not necessarily refer to different embodiments. The phrases “in one implementation” or “in some implementations” as used herein do not necessarily refer to the same implementation, and the phrases “in another implementation” or “in other implementations” as used herein do not necessarily refer to different implementations. For example, the claimed subject matter includes combinations of all or part of exemplary embodiments or implementations.

[0022] Generally, terms can be understood, at least in part, from their usage in the context. For example, terms such as “and,” “or,” or “and / or” as used herein can include a variety of meanings, which may depend at least in part on the context in which such terms are used. Generally, “or,” when used to relate a list such as A, B, or C, indicates A, B, and C used in an inclusive sense, and A, B, or C used in an exclusive sense. Furthermore, the terms “one or more” or “at least one” as used herein (at least in part on context) can be used to describe any feature, structure, or characteristic in a single sense, or can be used to describe a combination of features, structures, or characteristics in a plural sense. Similarly, terms such as “a,” “an,” or “the” can also be understood to express singular or plural usage, at least in part on context. Moreover, the terms “based on” or “determined by” can be understood not necessarily to convey a set of exclusive factors, but rather may allow for additional factors that are not necessarily explicitly described, at least in part on context.

[0023] This disclosure describes a method and apparatus for determining whether a user equipment (UE) needs to perform Multimedia Broadcast Multicast (MBMS) uplink feedback for a Multicast Service Channel (MTCH) transmission.

[0024] Next-generation (NG) or fifth-generation (5G) wireless communications can offer a range of capabilities, from fast downloads to supporting real-time, low-latency communication. Wireless communications can feature Multimedia Broadcast Multicast (MBMS) services. A radio access network (RAN) (e.g., a radio base station) can transmit data to a specific UE in a unicast manner; the RAN can simultaneously transmit data to at least one group of UEs in a multicast manner; or the RAN can simultaneously transmit data to all UEs capable of receiving the transmission in a broadcast manner. In some cases, multiple base stations can transmit the same data simultaneously, allowing a specific UE to receive the same data from multiple base stations.

[0025] Figure 1A and Figure 1B Various transmission modes of a wireless communication system 100 are illustrated, the system including a core network (CN) 110, a radio access network (RAN) 130, and one or more user equipments (UEs) (152, 154, and 156). RAN 130 may include a radio network base station or an NG radio access network (NG-RAN) base station or node, which may include a nodeB (NB, e.g., gNB) in a mobile telecommunications context. In one implementation, core network 110 may include a 5G core network (5GC), and interface 125 may include an NG interface.

[0026] Communication between the RAN and one or more UEs may include at least Multimedia Broadcast Multicast (MBMS) service and / or unicast service. UEs may receive data from the RAN via Point-to-Point (PTP) or unicast service, and / or via Point-to-Multipoint (PTM) or multicast or broadcast service.

[0027] refer to Figure 1A The first UE 152 can wirelessly receive communication from RAN 130 via downlink unicast 142 and wirelessly transmit communication to RAN 130 via uplink channel 141. Similarly, the second UE 154 can wirelessly receive communication from RAN 130 via downlink unicast 144 and wirelessly transmit communication to RAN 130 via uplink channel 143; and the third UE 156 can wirelessly receive communication from RAN 130 via downlink unicast 146 and wirelessly transmit communication to RAN 130 via uplink channel 145.

[0028] refer to Figure 1BRAN 130 can wirelessly communicate with one or more UEs (152, 154, and 156) via the Multicast Traffic Channel (MTCH) in MBMS service 160. In one implementation, a first UE 152 can wirelessly transmit communication to RAN 130 via uplink channel 161. Similarly, a second UE 154 can wirelessly transmit communication to RAN 130 via uplink channel 163; and a third UE 156 can wirelessly transmit communication to RAN 130 via uplink channel 165.

[0029] exist Figure 1A and Figure 1B In the wireless communication system 100, the RAN 130 can send MTCH transmissions within the MBMS service to one or more UEs. Several issues or challenges may arise, including the UE not providing the RAN with Hybrid Automatic Repeat Request Acknowledgment / Negative Acknowledgment (HARQ-ACK / NACK) information. HARQ-ACK information can indicate whether the MTCH transmission was correctly received by the UE. At least due to these issues and / or challenges, an MTCH transmission will not be retransmitted if a previous transmission of that MTCH was not correctly received by at least one UE. The MBMS service is a broadcast service; for example, MTCH transmissions can always be transmitted to different UEs via Point-to-Multipoint (PTM), and these UEs may not provide uplink feedback information such as HARQ-ACK, Channel State Information (CSI), etc. The uplink feedback mechanism for an MTCH transmission can be complex; for example, designing uplink feedback channel resources for the MBMS service can be challenging. Retransmitting the MTCH for a UE once it provides a NACK for the MTCH transmission is also challenging. Using uplink feedback information in MBMS services is challenging, at least due to the aforementioned issues and / or difficulties.

[0030] In the wireless communication system 100, the Media Access Control (MAC) layer can include data packets in MBMS service data or at least one MTCH transmission data, and then the data packets can be transmitted to the physical layer. At the physical layer, the data packets are transmitted via the Physical Downlink Shared Channel (PDSCH) and scheduled via the Physical Downlink Control Channel (PDCCH). The decoding result of the PDSCH corresponding to the MTCH transmission data can be used as uplink feedback information and transmitted to the base station via uplink feedback channel resources (corresponding to the MTCH transmission included in the PDSCH). Therefore, the uplink feedback channel resources correspond to one MTCH transmission, i.e., one PDSCH carrying the MTCH transmission. The uplink feedback information corresponds to one MTCH transmission, i.e., one PDSCH carrying the MTCH transmission. The following description focuses on the MTCH only as an example.

[0031] The method described above for allocating uplink feedback channel resources for MTCH transmission / MBMS service can also be fully applied to a PDCCH. The PDCCH schedules the PDSCH, and the PDSCH can contain one or more MTCH transmission data and / or MBMS service data. For example, the MTCH transmission in the above embodiments can be replaced with a PDCCH, and the uplink feedback channel resources allocated for MTCH transmission can be replaced with uplink channel resources allocated for a PDCCH that schedules the PDSCH, which carries the MTCH transmission. The UE can transmit uplink feedback information associated with a PDCCH through the uplink feedback channel resources corresponding to the PDCCH. For example, uplink feedback channel resources shared by at least one UE can be allocated for NACK; and / or uplink feedback channel resources shared by at least one UE can be allocated for discontinuous transmission (DTX).

[0032] In one implementation, uplink feedback channel resources can be allocated for NACK to be shared by a first UE (UE1) and a second UE (UE2), and uplink feedback channel resources can be allocated for DTX to be shared by UE1 and UE2. In this way, for UE1 and UE2, corresponding uplink feedback can be performed based on the actual decoding status of the PDCCH and the corresponding PDSCH as at least one of the following conditions.

[0033] For a given condition, when UE1 and / or UE2 correctly receive the PDCCH of the PDSCH carrying the MTCH transmission data, but fail to correctly decode the PDSCH, UE1 and / or UE2 may report NACK (or send a predefined signal, such as a sequence) in the uplink feedback channel resource corresponding to the NACK shared by UE1 and UE2.

[0034] Under another condition, when the uplink feedback channel resources are allocated to ACK for UE1 and UE2 to share, and UE1 and / or UE2 correctly decode the PDCCH of the PDSCH carrying MTCH transmission data, and correctly decode the PDSCH, UE1 and / or UE2 may report ACK (or send predefined signals such as sequences) in the uplink feedback channel resources corresponding to the ACK shared by UE1 and UE2.

[0035] In this way, the base station can determine that the PDCCH has not been correctly decoded by at least one UE, and therefore adjust the code rate used by the PDCCH based on the feedback from the UEs. UEs receiving the PDCCH share uplink feedback channel resources, which helps to save uplink feedback channel resources. In this way, it is equivalent to allocating two shared uplink feedback channel resources for uplink feedback information related to the PDCCH and downlink feedback information related to the PDSCH. If the PDCCH and / or PDSCH is not correctly received, the UE may only need to transmit the corresponding uplink feedback information.

[0036] MBMS services can be broadcast and received by all UEs in the cell. When the base station needs to transmit uplink feedback information (such as ACK / NACK) for a specific MTCH / MBMS, all UEs receiving that MTCH / MBMS transmission need to participate in the uplink feedback. Therefore, the following problem may arise: UEs may require a large amount of uplink feedback resources to transmit the feedback, which consumes significant resources and impacts the performance of the radio system.

[0037] This disclosure describes a method and apparatus for determining uplink feedback performed by a user equipment (UE) for an MTCH transmission. This disclosure can address at least some of the problems discussed above by reducing uplink feedback resources. This disclosure can reduce the number of UEs participating in uplink feedback, and therefore provides a solution where a small number of UEs participate in uplink feedback once, but the effect of uplink feedback is no less than the effect of all UEs participating in uplink feedback.

[0038] Figure 2 An exemplary radio access network or wireless communication base station 200 is illustrated. Base station 200 may include a radio transmit / receive (Tx / Rx) circuitry 208 for transmitting / receiving communications with one or more UEs and / or one or more other base stations. The base station may also include a network interface circuitry 209 for enabling communication between the base station and other base stations and / or the core network (e.g., optical or wired interconnects, Ethernet, and / or other data transmission media / protocols). Base station 200 may optionally include an input / output (I / O) interface 206 for communicating with operators, etc.

[0039] The base station may also include system circuitry 204. System circuitry 204 may include processor(s) 221 and / or memory 222. Memory 222 may include operating system 224, instructions 226, and parameters 228. The instructions 226 may be configured to perform base station functions for one or more of the processors 124. Parameters 228 may include parameters for supporting the execution of instructions 226. For example, parameters may include network protocol settings, bandwidth parameters, radio frequency mapping allocation, and / or other parameters.

[0040] Figure 3 An exemplary user equipment (UE) 300 is illustrated. UE 300 may be a mobile device, such as a smartphone or a mobile communication module located in a vehicle. UE 300 may include a communication interface 302, a system circuitry 304, input / output interfaces (I / O) 306, a display circuitry 308, and a storage device 309. The display circuitry may include a user interface 310. System circuitry 304 may include any combination of hardware, software, firmware, or other logic / circuit systems. System circuitry 304 may be implemented, for example, using one or more system-on-chip (SoC), application-specific integrated circuits (ASIC), discrete analog and digital circuits, and other circuit systems. System circuitry 304 may be part of the implementation of any desired functionality in UE 300. In this regard, system circuitry 304 may include logic that, for example, facilitates the decoding and playback of music and video, such as MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback; runs applications; accepts user input; saves and retrieves application data; establishes, maintains, and terminates (as an example) cellular phone calls or data connections for internet connectivity; establishes, maintains, and terminates wireless network connections, Bluetooth connections, or other connections; and displays relevant information on user interface 310. User interface 310 and input / output (I / O) interface 306 may include a graphical user interface, a touch-sensitive display, haptic feedback or other haptic outputs, voice or facial recognition inputs, buttons, switches, speakers, and other user interface elements. Other examples of I / O interface 306 may include a microphone, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headphone and microphone input / output jacks, a universal serial bus (USB) connector, a memory card slot, radiation sensors (e.g., IR sensors), and other types of inputs.

[0041] refer to Figure 3The communication interface 302 may include a radio frequency (RF) transmission (Tx) and reception (Rx) circuitry 316 for processing signal transmission and reception via one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceiver may be a wireless transceiver, including modulation / demodulation circuitry, a digital-to-analog converter (DAC), a shaping table, an analog-to-digital converter (ADC), filters, waveform shapers, preamplifiers, power amplifiers, and / or other logic for transmission and reception via one or more antennas or (for some devices) via a physical (e.g., wired) medium. The transmitted and received signals may follow any of a variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and encodings. As a specific example, the communication interface 302 may include a transceiver supporting transmission and reception under 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High-Speed ​​Packet Access (HSPA)+, 4G / LTE, and 5G standards. However, the techniques described below are applicable to other wireless communication technologies, whether they originate from the 3rd Generation Partnership Project (3GPP), the GSM Association, 3GPP2, IEEE, or other partners or standards bodies.

[0042] refer to Figure 3 The system circuitry 304 may include one or more processors 321 and a memory 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute instructions 326 to implement the desired functions of the UE 300. Parameters 328 can be provided and specify configuration and operational options for instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G, or other data that the UE 300 will transmit or has received via the communication interface 302. In various implementations, the system power of the UE 300 may be provided by power storage devices such as batteries or transformers.

[0043] This disclosure describes several embodiments of methods and apparatus for determining whether a UE performs uplink feedback for an MTCH transmission, which may be partially or wholly based on the above. Figure 2 and Figure 3 Implemented on the wireless network base station and / or user equipment described herein.

[0044] In various embodiments, references Figure 4A method 400 for wireless communication includes determining that a user equipment (UE) performs Multimedia Broadcast Multicast (MBMS) uplink feedback. Method 400 may include some or all of the following steps: step 410: receiving multicast traffic channel (MTCH) transmissions in MBMS service from a radio access network (RAN) by at least one UE; and step 420: determining by the UE to perform MBMS uplink feedback in response to determining that the UE's channel quality indicator (CQI) meets preset conditions.

[0045] In one implementation, MTCH transmissions in MBMS service can be transmitted from the RAN to one or more UEs via the Physical Downlink Shared Channel (PDSCH). MBMS uplink feedback corresponds to the PDSCH carrying the MTCH transmissions.

[0046] MBMS-related uplink feedback information may include at least one of the following: Hybrid Automatic Repeat Request Acknowledgment / Negative Acknowledgment (HARQ-ACK / NACK), NACK-only feedback, Channel State Information (CSI) feedback, or Receive State feedback.

[0047] In one implementation, in response to MBMS-related uplink feedback information including HARQ-ACK information, the UE performing MBMS uplink feedback may include: generating HARQ-ACK information, constructing a HARQ-ACK codebook, and then transmitting the HARQ-ACK codebook corresponding to the MBMS-related uplink feedback information transmitted via the Physical Uplink Control Channel (PUCCH) and the MTCH.

[0048] In another implementation, in response to MBMS-related uplink feedback information including CSI feedback, the UE performing MBMS uplink feedback may include: measuring CSI information, generating CSI feedback information, and then transmitting the CSI feedback information corresponding to the MBMS-related uplink feedback information transmitted with MTCH.

[0049] In one implementation, alternatively, method 400 may include at least one UE receiving configuration information, including a preset threshold, from the RAN via a configuration message. The configuration message may include at least one of the following: a Physical Downlink Control Channel (PDCCH) message, a Single Cell Multicast Control Channel (SC-MCCH) message, a Multi-Cell Multicast Control Channel (MC-MCCH) message, or a Radio Resource Control (RRC) message.

[0050] In another implementation, the preset threshold in the configuration information can be a Channel Quality Indicator (CQI) threshold. This method can determine one or more UEs that need to participate in uplink feedback for channel transmission. Channel transmission may include a PDSCH or MTCH carrying one or more MTCHs.

[0051] If the UE's CQI is not higher than a preset threshold, the UE performs MBMS uplink feedback; if the UE's CQI is higher than a preset threshold, the UE does not perform MBMS uplink feedback.

[0052] For example, the CQI threshold is set to A. One or more UEs with a CQI higher than A may not perform uplink feedback. This is considered to mean that one or more UEs have relatively good CQI and are generally believed to be able to correctly receive channel transmissions that require uplink feedback with a high probability. Therefore, one or more UEs can choose not to participate in uplink feedback, thereby reducing the number of UEs requiring uplink feedback.

[0053] One or more UEs with a CQI not higher than A need to perform uplink feedback. This is considered to be because the CQI of one or more UEs is relatively poor, and they are generally considered to be less likely to correctly receive channel transmissions that require uplink feedback with a high probability.

[0054] In another implementation, the RAN sends a Physical Downlink Control Channel (PDCCH) indicating a CQI threshold to at least one UE. When the UE's CQI is less than the CQI threshold, the UE performs MBMS uplink feedback. When the UE's CQI is greater than or equal to the CQI threshold, the UE does not need to perform MBMB uplink feedback.

[0055] In another implementation, the RAN sends a Physical Downlink Control Channel (PDCCH) indicating a CQI threshold to at least one UE. When CQI2 - CQI1 > T (where CQI2 is the UE's CQI, CQI1 is the CQI threshold, and T is a preset threshold), the UE performs MBMS uplink feedback. When CQI2 - CQI1 ≤ T, the UE does not need to perform MBMS uplink feedback.

[0056] Preset thresholds in configuration messages configured by the RAN may not change frequently, and therefore can be considered semi-static parameters / thresholds. CQI thresholds in the PDCCH can change frequently and / or easily, and therefore can be considered dynamic parameters / thresholds. By combining semi-static and dynamic parameters / thresholds, this disclosure provides a general solution to the above problems.

[0057] In another implementation, when the UE's CQI is lower than a preset threshold, the UE performs MBMS uplink feedback, and when the UE's CQI is not lower than the preset threshold, the UE does not perform MBMS uplink feedback.

[0058] In another implementation, the RAN sends a Physical Downlink Control Channel (PDCCH) indicating a CQI threshold to at least one UE. When the CQI threshold is greater than the UE's CQI, the UE performs MBMS uplink feedback. When the CQI threshold is not greater than the UE's CQI, the UE does not perform MBMS uplink feedback.

[0059] In another implementation, the RAN sends a Physical Downlink Control Channel (PDCCH) indicating a CQI threshold to at least one UE. When CQI4 - CQI3 < T (where CQI4 is the UE's CQI, CQI3 is the CQI threshold, and T is a preset threshold), the UE performs MBMS uplink feedback. When CQI4 - CQI3 ≥ T, the UE does not perform MBMS uplink feedback.

[0060] Throughout the specification and claims, embodiments and / or implementations are described that perform actions in response to comparing two quantities (A and B). These embodiments and / or implementations of how to handle the condition where the two quantities are equal are merely examples, and the present disclosure is not limited to these embodiments and / or implementations. The condition where the two quantities are equal can be treated the same as A > B or the same as A < B. For example, one implementation may describe performing a first action when A > B and a second action when A ≤ B. The present disclosure also includes another implementation where a first action is performed when A ≥ B and a second action is performed when A < B.

[0061] In various embodiments, reference Figure 5 A method 500 for wireless communication includes determining that a User Equipment (UE) performs Multimedia Broadcast Multicast Service (MBMS) uplink feedback. Method 500 may include some or all of the following steps: Step 510: receiving, by at least one UE, a Multicast Traffic Channel (MTCH) transmission in an MBMS service from a Radio Access Network (RAN); and Step 520: determining, by the UE, to perform MBMS uplink feedback in response to determining that a preset uplink feedback condition is met. In one implementation, performing MBMS uplink feedback includes transmitting MBMS-related uplink feedback information corresponding to the MTCH transmission; and the resources for transmitting the MBMS-related uplink feedback information may include a Physical Uplink Control Channel (PUCCH). In another implementation, the MBMS-related uplink feedback information may include at least one of the following: Hybrid Automatic Repeat Request Acknowledgment / Negative Acknowledgment (HARQ-ACK / NACK), NACK-only feedback, Channel State Information (CSI) feedback, or reception status feedback. In another implementation, at least one UE may include at least one of the following: all UEs receiving the MTCH transmission, UEs receiving the MTCH transmission, or a group of UEs receiving the MTCH transmission.

[0062] The base station can configure uplink feedback conditions to allow uplink feedback for MBMS services. When one or more UEs meet the uplink feedback conditions, the corresponding one or more UEs perform uplink feedback for MTCH transmissions. When one or more UEs do not meet the uplink feedback conditions, the corresponding one or more UEs do not perform uplink feedback for MTCH transmissions.

[0063] In one embodiment, configuring the uplink feedback condition may include a time period and a threshold. The time period can serve as the time range for statistical parameters. Statistical parameters may include, but are not limited to, the number of PDSCHs correctly received carrying MTCH transmissions, the number of PDSCHs incorrectly received carrying MTCH transmissions, and the total number of PDSCHs carrying MTCH transmissions. These statistical parameters, or values ​​obtained between them through predefined calculation rules, can be compared with a predefined threshold to determine whether the UE performs uplink feedback.

[0064] In one implementation, method 500 may optionally include at least one UE receiving configuration information, including preset uplink feedback conditions, from the RAN via a configuration message. The configuration message may include at least one of the following: a physical downlink control channel (PDCCH) message, a single-cell multicast control channel (SC-MCCH) message, a multi-cell multicast control channel (MC-MCCH) message, or a radio resource control (RRC) message.

[0065] In another implementation, the configuration information includes a time period and a preset threshold. When the cumulative number of times the Physical Downlink Shared Channel (PDSCH) carrying MTCH transmissions is correctly received by the UE during the time period exceeds the preset threshold, the UE performs MBMS uplink feedback. When the cumulative number of times the Physical Downlink Shared Channel (PDSCH) carrying MTCH transmissions is correctly received by the UE during the time period does not exceed the preset threshold, the UE does not perform MBMS uplink feedback. This implementation can be performed per MTCH, per UE, or per UE group.

[0066] In another implementation, the configuration information includes a time period and a preset threshold. When the ratio of a first number to a second number exceeds the preset threshold during this time period, the UE performs MBMS uplink feedback. The first number is the number of Physical Downlink Shared Channels (PDSCHs) carrying MTCH transmissions that are incorrectly received by the UE, and the second number is the number of PDSCHs carrying MTCH transmissions that are correctly received by the UE. When the ratio of the first number to the second number does not exceed the preset threshold during this time period, the UE does not perform MBMS uplink feedback. For example, during this time period, it is determined whether the ratio of incorrectly received PDSCHs (for MTCH transmissions) to correctly received PDSCHs (for MTCH transmissions) exceeds the threshold. When the threshold is exceeded, the UE performs uplink feedback for MTCH transmissions. When the threshold is not exceeded, the UE does not perform uplink feedback. This implementation can be performed per MTCH, per UE, or per group of UEs.

[0067] In another implementation, the configuration information includes a preset Quality of Service (QoS) threshold. When the QoS of the MTCH transmission received by the UE is lower than the preset QoS threshold, the UE performs MBMS uplink feedback. When the QoS of the MTCH transmission received by the UE is not lower than the preset QoS threshold, the UE does not perform MBMS uplink feedback. For example, the base station can set the uplink feedback threshold based on the QoS (Quality of Service) corresponding to the MTCH transmission. The QoS required for the MTCH transmission is set as the threshold. When the UE receives an MTCH transmission, if the QoS of the MTCH on the UE side is lower than the threshold, the UE needs to perform uplink feedback; if the QoS of the MTCH on the UE side is not lower than the threshold, the UE does not perform uplink feedback. The threshold in this implementation can be configured per MTCH, per UE, or per UE group.

[0068] In another implementation, the configuration information includes a preset quality threshold. When the reception quality of the MTCH transmission received by the UE is lower than the preset quality threshold, the UE performs MBMS uplink feedback. When the reception quality of the MTCH transmission received by the UE is not lower than the preset quality threshold, the UE does not perform MBMS uplink feedback. In one implementation, the reception quality of the MTCH transmission received by the UE can include multiple quantization levels, such as, but not limited to, excellent, good, fair, and poor. For example, the base station can set the conditions for uplink feedback based on predefined reception quality. The base station and the UE can quantize the MTCH reception quality into multiple levels. The base station configures the reception quality threshold. When the UE's reception quality is lower than the threshold, the UE performs uplink feedback; otherwise, the UE does not perform uplink feedback. For example, the reception quality is quantized into four levels, such as "excellent," "good," "average," and "poor." The threshold can be set to any level, such as the "poor" level. The threshold in this implementation can be configured per MTCH, per UE, or per group of UEs.

[0069] In various embodiments, references Figure 6 A method 600 for wireless communication includes determining that a user equipment (UE) performs Multimedia Broadcast Multicast (MBMS) uplink feedback. Method 600 may include some or all of the following steps: step 610: receiving a multicast traffic channel (MTCH) transmission in MBMS service from a radio access network (RAN) by at least one UE; and step 620: determining by the UE to perform MBMS uplink feedback in response to a first value in signaling received by the UE. In one implementation, performing MBMS uplink feedback includes transmitting MBMS-related uplink feedback information corresponding to the MTCH transmission; in another implementation, the MBMS-related uplink feedback information may include at least one of the following: Hybrid Automatic Repeat Request Acknowledgment / Nack Acknowledgment (HARQ-ACK / NACK), NACK-only feedback, Channel State Information (CSI) feedback, or Receive State feedback. In another implementation, at least one UE may include at least one of the following: all UEs receiving the MTCH transmission, UEs receiving the MTCH transmission, or a group of UEs receiving the MTCH transmission.

[0070] In one embodiment, a first new signaling may be introduced. This first new signaling may be used to notify the UE whether it needs to perform uplink feedback for the PDSCH carrying the MTCH transmission. When the parameters in the signaling are configured to notify the UE that it needs to perform uplink feedback for the Physical Downlink Shared Channel (PDSCH) carrying the MTCH transmission, the UE performs MBMS uplink feedback. Performing MBMS uplink feedback includes transmitting MBMS-related uplink feedback information corresponding to the MTCH transmission. When the parameters in the signaling are not configured to notify the UE that it needs to perform uplink feedback for the Physical Downlink Shared Channel (PDSCH) carrying the MTCH transmission, the UE does not perform MBMS uplink feedback. For example, one or more UEs may be notified to perform uplink feedback for the MTCH transmission. Alternatively, one or more UEs may be notified not to perform uplink feedback for the MTCH transmission.

[0071] In another embodiment, a second new signaling can be introduced. This second new signaling can be used to notify the UE whether uplink feedback is required or not for the MTCH transmission. When the parameters in the signaling are configured to notify the UE that uplink feedback is required for the MTCH transmission, the UE performs MBMS uplink feedback. Performing MBMS uplink feedback includes transmitting MBMS-related uplink feedback information corresponding to the MTCH transmission. When the parameters in the signaling are not configured to notify the UE that uplink feedback is required for the MTCH transmission, the UE does not perform MBMS uplink feedback. For example, when the second signaling notifies the first MTCH to perform uplink feedback, the UE receiving the first MTCH transmission needs to perform uplink feedback. When the second signaling does not require uplink feedback for the second MTCH, the UE receiving the second MTCH transmission may not perform uplink feedback.

[0072] In one implementation, the base station notifies the UE to perform uplink feedback for one or more MTCH transmissions via the PDCCH to schedule the PDSCH carrying the MTCH transmission. This signaling includes a PDCCH received by the UE from the RAN, configured to schedule the PDSCH carrying the MTCH transmission. When a parameter in the PDCCH is a first value configured by the RAN, the parameter instructs the UE to perform uplink feedback for the MTCH transmission, and the UE performs uplink feedback. When a parameter in the PDCCH is a second value configured by the RAN, the parameter instructs the UE not to perform uplink feedback for the MTCH transmission, and the UE does not perform uplink feedback. For example, a new parameter field is introduced into the PDCCH, or an existing parameter field in the PDCCH is reinterpreted. This parameter field is used to indicate to the UE whether uplink feedback is required (or not required) for the MTCH transmission. If the base station wants the UE to perform uplink feedback for a first MTCH transmission, the base station sets the corresponding value of this parameter field in the PDCCH that schedules the PDSCH carrying the first MTCH transmission, causing the UE receiving the MTCH1 transmission to perform the corresponding uplink feedback. Accordingly, if the base station does not want the UE to perform uplink feedback for the first MTCH transmission, the base station sets the corresponding value of this parameter field in the PDCCH that schedules the PDSCH carrying the first MTCH transmission, so that the UE receiving the first MTCH transmission does not perform the corresponding uplink feedback. In one implementation, this parameter field in the PDCCH can be extended to indicate that uplink feedback is required (or not required) for multiple MTCH transmissions. Using the PDCCH to notify the MTCH that uplink feedback is required (or not required) provides high flexibility because the PDCCH can be transmitted intensively.

[0073] In one implementation, a new parameter can be introduced into the single-cell multicast control channel (SC-MCCH) to indicate whether uplink feedback is required (or not) for MTCH transmissions. The SC-MCCH can be configured as an MBMS control channel. This signaling can include the SC-MCCH received by the UE from the RAN. When the parameter in the SC-MCCH is a first value configured by the RAN, the parameter instructs the UE to perform uplink feedback for MTCH transmissions, and the UE performs uplink feedback. When the parameter in the SC-MCCH is a second value configured by the RAN, the parameter instructs the UE not to perform uplink feedback for MTCH transmissions, and the UE does not perform uplink feedback. For example, if the base station wants to perform uplink feedback for a first MTCH, the base station sets the new parameter in the SC-MCCH to the corresponding value to indicate that uplink feedback is required for the first MTCH. Accordingly, on the UE side, when the SC-MCCH is received, the UE knows through the new parameter that uplink feedback is required for the first MTCH, and then the UE receiving the first MTCH transmission performs uplink feedback.

[0074] Optionally, when a parameter is changed, the RAN updates the update indication information corresponding to the SC-MCCH. When the UE receives the updated update indication information corresponding to the SC-MCCH, the UE receives the SC-MCCH from the RAN to obtain the changed parameters again. For example, when the value of a new parameter in the SC-MCCH changes, it should cause the update indication information corresponding to the SC-MCCH to also change. In this way, for a UE that is monitoring the update indication information corresponding to the SC-MCCH, when the UE detects a change in the update indication information, the UE can know that the SC-MCCH has changed, allowing the UE to receive the SC-MCCH again and thus obtain the latest value of the new parameter.

[0075] In one implementation, a new Radio Resource Control (RRC) signaling can be sent by the base station to the UE, indicating that uplink feedback is required (or not required) for MTCH transmissions. For example, a new RRC parameter is introduced in a system broadcast message, or in a system broadcast message of the MBMS, or in a UE-specific RRC message. This signaling includes an RRC received by the UE from the RAN, and the RRC configured by the RAN includes the MBMS system broadcast message. When the parameter in the RRC is a first value configured by the RAN, the parameter instructs the UE to perform uplink feedback for MTCH transmissions, and the UE performs uplink feedback. When the parameter in the RRC is a second value configured by the RAN, the parameter instructs the UE not to perform uplink feedback for MTCH transmissions, and the UE does not perform uplink feedback. The RRC includes at least one of the following: a system broadcast message, or a UE-specific RRC message. For example, when the base station wants to perform uplink feedback for a first MTCH, the base station sets a new parameter in the MBMS system broadcast message to the corresponding value to indicate that uplink feedback is required for the first MTCH. Correspondingly, on the UE side, when the system broadcast message of MBMS is received, the UE knows through the new parameters that the first MTCH needs to perform uplink feedback, and then the UE that receives the first MTCH transmission performs uplink feedback.

[0076] When a parameter is changed, the RAN updates the update indication information corresponding to the MBMS system broadcast message. When the UE receives the updated update indication information corresponding to the MBMS system broadcast message, the UE receives an RRC from the RAN to retrieve the changed parameter again. For example, when the value of a new parameter in the MBMS system broadcast message changes, it should cause the update indication information corresponding to the MBMS system broadcast message to also change. In this way, for a UE monitoring the update indication information corresponding to the MBMS system broadcast message, when the UE detects a change in the update indication information, the UE can know that the MBMS system broadcast message has changed; thus, the UE can receive the MBMS system broadcast message again to obtain the latest value of the new parameter.

[0077] In one implementation, a new Media Access Control (MAC) element (CE) can be introduced to notify the UE that uplink feedback is required (or not required) for MTCH transmissions. When the MAC CE is a first value configured by the RAN, the MAC CE instructs the UE to perform uplink feedback for MTCH transmissions, and the UE performs uplink feedback. When the MAC CE is a second value configured by the RAN, the MAC CE instructs the UE not to perform uplink feedback for MTCH transmissions, and the UE does not perform uplink feedback. For one example, the MAC CE can be designed to notify the UE per UE that uplink feedback is required (or not required) for MTCH transmissions. The MAC CE can be transmitted based on a unicast PDSCH or based on a PDSCH carrying the MTCH transmission. Here, the MAC CE can also include: for which MTCH transmissions the UE needs (or does not need) to perform uplink feedback. For example, if the base station wants a first UE to provide uplink feedback for a first MTCH transmission, the base station can transmit a MAC CE to the first UE, and the MAC CE contains the first MTCH information. On the first UE side, after receiving the MAC CE, the first UE learns that uplink feedback needs to be performed for the first MTCH transmission. Alternatively, the MAC CE may only notify the first UE that uplink feedback needs to be performed for MTCH transmissions, and then the base station may determine which MTCH transmissions require uplink feedback through other methods (such as the other methods mentioned above).

[0078] In another implementation, the MAC CE is transmitted from the RAN to the UE based on a unicast PDSCH or a PDSCH carrying MTCH transmission; and in response to receiving the MAC CE containing MTCH information, the UE is configured to perform uplink feedback for the MTCH transmission. For example, the MAC CE can also be designed per MTCH to notify the MTCH that uplink feedback is required (or not required) for the transmission. The MAC CE can be transmitted based on a PDSCH carrying MTCH transmission or based on a unicast PDSCH. Here, the UE performs uplink feedback for the PDSCH carrying MCTH transmission. For example, if the base station wants the UE to perform uplink feedback for the first MTCH transmission, the base station can transmit the MAC CE in the PDSCH carrying the first MTCH transmission. On the corresponding UE side, if the UE receives the PDSCH carrying the first MTCH transmission, the UE obtains the MAC CE and learns that the UE receiving the MTCH1 transmission needs to perform uplink feedback for the first MTCH transmission.

[0079] In various embodiments, references Figure 7A method 700 for wireless communication includes determining that a user equipment (UE) performs Multimedia Broadcast Multicast (MBMS) uplink feedback. Method 700 may include some or all of the following steps: step 710: receiving a multicast traffic channel (MTCH) transmission in MBMS service from a radio access network (RAN) by at least one UE; and step 720: in response to determining that uplink feedback channel resources for MBMS uplink feedback are configured by the RAN, the UE determines to perform MBMS uplink feedback. In one implementation, the UE receiving the MTCH transmission performs uplink feedback for the MTCH transmission, and performing MBMS uplink feedback includes transmitting MBMS-related uplink feedback information corresponding to the MTCH transmission. In another implementation, the MBMS-related uplink feedback information may include at least one of the following: Hybrid Automatic Repeat Request Acknowledgment / Negative Acknowledgment (HARQ-ACK / NACK), NACK-only feedback, Channel State Information (CSI) feedback, or Receive State feedback.

[0080] In one implementation, the base station and the UE may agree that if the UE is configured with uplink feedback channel resources, it needs to perform uplink feedback for the MTCH transmission when the UE is receiving an MTCH transmission. Here, the uplink feedback channel resources are configured per UE and / or per MTCH. Receiving an MTCH transmission includes the UE receiving the PDSCH carrying the MTCH transmission. The RAN configures the uplink feedback channel resources corresponding to the MTCH transmission per UE; and / or the RAN configures the uplink feedback channel resources corresponding to the MTCH transmission per MTCH transmission.

[0081] For uplink feedback channel resources, which are configured on a per-UE basis, when the base station wants the UE to provide uplink feedback corresponding to the MTCH transmission, the base station can configure an uplink feedback channel for the UE. On the UE side, the UE acquires the uplink feedback channel resource, and the UE performs uplink feedback for the MTCH transmission being received.

[0082] Another example of uplink feedback channel resources being per MTCH is that if the base station wants the UE to provide uplink feedback for MTCH transmissions, the base station can configure downlink feedback channel resources corresponding to the MTCH. On the UE side, the UE acquires the uplink feedback channel resources corresponding to the MTCH transmission, and the UE receiving the MTCH transmission performs uplink feedback.

[0083] Without any limitations, some and / or all of the embodiments and implementations described above may be used in combination or alternative ways.

[0084] This disclosure describes methods, apparatus, and computer-readable media for wireless communication. This disclosure addresses the problem of determining whether a user equipment (UE) needs to perform uplink feedback for a multicast traffic channel (MTCH) transmission. The methods, apparatus, and computer-readable media described in this disclosure can improve the performance of wireless communication, thereby enhancing efficiency and overall performance, by determining whether the UE needs to perform uplink feedback for MTCH transmission. The methods, apparatus, and computer-readable media described in this disclosure can improve the overall efficiency of wireless communication systems.

[0085] References to features, advantages, or similar language in this specification do not imply that all features and advantages achievable with this solution should be included in or be incorporated into any single implementation of this solution. Rather, references to features and advantages are understood to indicate that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of this solution. Therefore, the discussion of features and advantages, as well as similar language, throughout this specification may, but is not necessarily, refer to the same embodiments.

[0086] Furthermore, the features, advantages, and characteristics described in this solution can be combined in any suitable manner in one or more embodiments. Based on the description herein, those skilled in the art will recognize that this solution can be practiced without one or more of a particular feature or advantage of a particular embodiment. In other instances, additional features and advantages that may not be present in all embodiments of this solution may be recognized in certain embodiments.

Claims

1. A method for wireless communication, comprising: determining, by a user equipment (UE), to perform multimedia broadcast multicast (MBMS) uplink feedback by: receiving, by the UE, a multicast traffic channel (MTCH) transmission of a single MBMS service from a radio access network (RAN), wherein the MTCH transmission is carried on a physical downlink shared channel (PDSCH); and receiving, by the UE, a physical downlink control channel (PDCCH) from the RAN, the PDCCH being configured for scheduling the PDSCH, wherein in response to a parameter in the PDCCH being a first value configured by the RAN, the parameter in the PDCCH indicates the UE to perform uplink feedback for the PDSCH, and in response to the parameter in the PDCCH being a second value configured by the RAN, the parameter in the PDCCH indicates the UE to not perform uplink feedback for the PDSCH, wherein information of the uplink feedback comprises at least one of: a hybrid automatic repeat request acknowledgement / negative acknowledgement (HARQ-ACK / NACK), a NACK-only feedback, or a reception status feedback; and wherein the performing uplink feedback comprises: transmitting the information of the uplink feedback corresponding to the PDSCH.

2. The method of claim 1, wherein: in response to the parameter being changed, the RAN updates updated indication information; and in response to receiving the updated indication information, the UE receives an RRC from the RAN to reacquire the changed parameter.

3. A method for wireless communication, comprising: determining, by a radio access network (RAN), to receive multimedia broadcast multicast (MBMS) uplink feedback by: sending, by the RAN, a multicast traffic channel (MTCH) transmission of a single MBMS service to at least one user equipment (UE), wherein the MTCH transmission is carried on a physical downlink shared channel (PDSCH); and sending, by the RAN, a physical downlink control channel (PDCCH) to the UE, the PDCCH being configured for scheduling the PDSCH, wherein in response to a parameter in the PDCCH being configured as a first value, the parameter in the PDCCH is used to indicate the UE to perform uplink feedback for the PDSCH, and in response to the parameter in the PDCCH being configured as a second value, the parameter in the PDCCH is used to indicate the UE to not perform uplink feedback for the PDSCH, wherein information of the uplink feedback comprises at least one of: a hybrid automatic repeat request acknowledgement / negative acknowledgement (HARQ-ACK / NACK), a NACK-only feedback, or a reception status feedback; wherein the performing uplink feedback comprises: transmitting the information of the uplink feedback corresponding to the PDSCH.

4. The method of claim 3, wherein: in response to the parameter being changed, the RAN updates updated indication information; and in response to receiving the updated indication information, the UE receives an RRC from the RAN to reacquire the changed parameter. The RAN sends RRC to the UE to facilitate the UE to re-acquire the changed parameters.

5. An apparatus for communication, comprising: a memory that stores instructions; and a processor in communication with the memory, wherein when the processor executes the instructions, the processor is configured to cause the apparatus to perform: determining that the apparatus performs multimedia broadcast multicast (MBMS) uplink feedback by: receiving, by the apparatus, a multicast traffic channel (MTCH) transmission of a single MBMS service from a radio access network (RAN), wherein the MTCH transmission is carried on a physical downlink shared channel (PDSCH); and receiving, by the apparatus, a physical downlink control channel (PDCCH) from the RAN, the PDCCH being configured for scheduling the PDSCH, wherein in response to a parameter in the PDCCH being a first value configured by the RAN, the parameter in the PDCCH indicates that the apparatus performs uplink feedback for the PDSCH, and in response to the parameter in the PDCCH being a second value configured by the RAN, the parameter in the PDCCH indicates that the apparatus does not perform uplink feedback for the PDSCH, wherein information of the uplink feedback comprises at least one of: hybrid automatic repeat request acknowledgement / negative acknowledgement (HARQ-ACK / NACK), NACK-only feedback, or reception status feedback; and wherein the performing uplink feedback comprises: transmitting information of the uplink feedback corresponding to the PDSCH.

6. The apparatus of claim 5, wherein: in response to the parameter being changed, the RAN updates updated indication information; and in response to receiving the updated indication information, the apparatus receives RRC from the RAN to re-acquire the changed parameters.

7. A wireless communication node, comprising: a memory that stores instructions; and a processor in communication with the memory, wherein when the processor executes the instructions, the processor is configured to cause the wireless communication node to perform: determining that the communication node receives multimedia broadcast multicast (MBMS) uplink feedback by: transmitting, by the communication node, a multicast traffic channel (MTCH) transmission of a single MBMS service to at least one user equipment (UE), wherein the MTCH transmission is carried on a physical downlink shared channel (PDSCH); and transmitting, by the communication node, a physical downlink control channel (PDCCH) to the UE, the PDCCH being configured for scheduling the PDSCH, wherein in response to a parameter in the PDCCH being configured as a first value, the parameter in the PDCCH is used to indicate that the UE performs uplink feedback for the PDSCH, and in response to the parameter in the PDCCH being configured as a second value, the parameter in the PDCCH is used to indicate that the UE does not perform uplink feedback for the PDSCH, wherein the information of the uplink feedback comprises at least one of: a hybrid automatic repeat request acknowledgement / negative acknowledgement (HARQ-ACK / NACK), a NACK-only feedback, or a reception status feedback; and wherein the performing the uplink feedback comprises: transmitting the information of the uplink feedback corresponding to the PDSCH.

8. The wireless communication node of claim 7, wherein: in response to the parameter being changed, the communication node updates updated indication information; and the communication node sends an RRC to the UE to facilitate the UE to acquire the changed parameter again.

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