EP4512198A1

EP4512198A1 - Method and apparatus for beam failure recovery

Info

Publication number: EP4512198A1
Application number: EP22937976.3A
Authority: EP
Inventors: Samuli Heikki TURTINEN; Timo Koskela; Chunli Wu
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2025-02-26
Also published as: EP4512198A4; CN119586296A; WO2023201740A1

Abstract

Embodiments of the present disclosure relate to multiple Beam Failure Detection Reference Signal (BFD-RS) set failure in spell. The method performed by a terminal device comprising: initiating a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; receiving a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; stopping the random access procedure upon receipt of the response to the first BFR for the first beam failure. In this way, unnecessary random access procedure can be avoided and terminal device power saving can be achieved.

Description

METHOD AND APPARATUS FOR BEAM FAILURE RECOVERY

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a method, device, apparatus and computer readable storage medium for Beam Failure Recovery (BFR) .

BACKGROUND

With development of communication technology, terminal devices may be connected to a serving cell via multiple transmit-receive points (multi-TRP) in the serving cell, to improve the communication capacity, robustness and configuration flexibility of the serving cell.
In a multi-TRP scenario, a terminal device is served by multiple TRPs each configured with a Beam Failure Detection (BFD) -Reference Signal (RS) set associated with beams for the terminal device. The BFD-RS sets are configured for fast beam failure detection. A beam failure recovery may be triggered when a beam failure associated with a BFD-RS set is detected. When beam failures associated with all sets of BFD-RS of the TRPs occur concurrently, it might require initiating a random access procedure to perform beam failure recovery.
SUMMARY
In general, example embodiments of the present disclosure provide a solution for beam failure recovery in spell.
In a first aspect, there is provided a terminal device. The terminal device may comprise at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to initiate a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; receive a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; and stop the random access procedure upon receipt of the response to the first BFR for the first beam failure.
In a second aspect, there is provided a terminal device. The terminal device may comprise at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to initiate a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and include BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
In a third aspect, there is provided a method. The method may comprise initiating a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; receiving a response to the first BFR for the first beam failure , wherein the response indicates a successful completion of the first BFR for the first beam failure; and stopping the random access procedure upon receipt of the response to the first BFR for the first beam failure.
In a fourth aspect, there is provided a method. The method may comprise initiating a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and including BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
In a fifth aspect, there is provided an apparatus. The apparatus may comprise means for initiating a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; means for receiving a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; and means for stopping the random access procedure upon receipt of the response to the first BFR for the first beam failure..
In an sixth aspect, there is provided an apparatus. The apparatus may comprise means for initiating a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and means for including BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to the above third to fourth aspect.
It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:
Fig. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;
Fig. 2 illustrates a flowchart of an example method implemented at a terminal device according to some example embodiments of the present disclosure;
Fig. 3 illustrates a flowchart of an example method implemented at a terminal device according to some example embodiments of the present disclosure;
Fig. 4a illustrates an example of Enhanced BFR and Truncated Enhanced BFR MAC CE with one octet Ci field;
Fig. 4b illustrates an example of Enhanced BFR and Truncated Enhanced BFR MAC CE with four octet Ci field;
Fig. 5 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and
Fig. 6 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.
Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.
In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.
References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.
As used in this application, the term “circuitry” may refer to one or more or all of the following:
(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and
(b) combinations of hardware circuits and software, such as (as applicable) :
(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and
(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and
(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.
This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.
As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) communication protocols, and/or beyond. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.
As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.
The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.
As used herein, the term “TRP” refers to a transmit-receive point having an antenna array (with one or more antenna elements) at the network side located at a specific geographical location, which may be used for transmitting and receiving signals to/from the terminal device. In embodiment of the present disclosure, a TRP may refer to Macro Cell, micro cell, an RRH, a relay, a femto node, a pico node, etc. Although some embodiments of the present disclosure are described with reference to two TRPs for example, these embodiments are only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the present disclosure. It is to be understood that the present disclosure described herein can be implemented in various manners other than the ones described below.
In a multi-TRP scenario, a TRP may be configured with a BFD-RS set to be detected by the terminal device, the BFD-RS set is associated with beam (s) available for the terminal device and thus the terminal device may perform beam failure detection by means of the BFD-RS set. Additionally, the TRP may be further configured with a set of candidate beams corresponding to respective BFD-RS sets. As used herein, the term “multi-TRP” may refer to that the terminal device is served by multiple TRPs and thus configured with a plurality of BFD-RS sets and/or a plurality of sets of candidate beams for multiple TRPs. The term “multi-TRP” may also mean the TRPs serving one or more terminal devices belong to a same cell.
In the multi-TPR operations, a terminal device may communicate with a serving cell via multiple TRPs. The serving cell may be a Primary Cell (PCell) or a Primary Secondary Cell (PSCell) , and PCell and PSCell may be refereed as Special Cell (SpCell) herein after.
In some example embodiments, a terminal device may connect to the network via the two TRPs. The two TRPs provide beams sets for the terminal device. Meanwhile, the TRPs transmit sets of reference signals (TS) for beam failure detection (BFD) associated with the beam sets to the terminal device. The sets of BFD RS are used to detect the beam failures. When a beam failure of a set of reference signal (s) occurs or is detected for one TRP, the terminal device may continue the communication with the network via another TRP and report the beam failure associated with the one TRP to the network. When both beam failure associated with two set of reference signals occurs concurrently (or occurs one after another) , the terminal device may initiate a random access procedure to ensure that the communications between the terminal and network can be maintain.
However, there may be a situation where a random access procedure is triggered or initiated but a response to the previously reported beam failure is received thereafter. For example, a first beam failure of a first set of reference signal is reported to the network, but the response to the first beam failure is not received when the second beam failure of a second set of reference signal is detected. In such a case, the detection of the second beam failure will trigger the random access procedure but thereafter the response to the first beam failure may be received during the random access procedure. There is a need to decide how to proceed with the beam recovery for such case in order to improve the efficiency and/or reduce the delay of beam recovery.
Example embodiments of the present disclosure provide a solution of beam failure recovery. In this solution, if a terminal device detects beams failures of two sets of BDF RS, the terminal device initiates a random access procedure for BFR for a first beam failure of a first set of BFD RS and/or the second beam failure of a second set of BFD RS during the random access procedure. When the terminal device receives a response of the first BFR for the first beam failure, which indicates a successful completion of the first BFR for the first beam failure, the terminal device may stop the random access procedure upon receipt of the response of the first BFR for the first beam failure. As such, unnecessary random access procedure can be avoided and UE power can be saved. Alternatively, the terminal device may stop or continue the random access procedure, dependent on different stages of the random access procedure. Additionally or alternatively, the terminal device may include BFR information for both the first beam and the second beam in MsgA or Msg3 in the random access procedure. Additionally, the terminal device may further determine whether to include BFR information for both the first beam and the second beam in MsgA or Msg3 dependent on status of the first beam failure recovery and/or status of the random access procedure.
As such, in some embodiments of the present disclosure, unnecessary random access procedure can be avoided and terminal device power saving can be achieved. In addition, in some embodiments of the present disclosure, a network device will receive clear information about the beam failure situation in the terminal device, and a specification in terms of how the Enhanced (Truncated) BFR MAC CE is encoded for SpCell will be clear when both BFD-RS sets are failure. Therefore, the system efficiency can be improved.
Example embodiments of the present disclosure for determination of concurrent beam failure will be described below with reference to FIGS. 1-6.
FIG. 1 illustrates an example environment 100 in which example embodiments of the present disclosure can be implemented.
The environment 100, which may be a part of a communication network, comprises a serving cell, such as Spcell 101, a first TRP 105, a second TRP 110, a terminal device 120 as well as a network device 130. It is to be understood that the number of TRPs and terminal devices shown in the environment 100 only for the purpose of illustration, but without any limitation to the scope of the present disclosure. In some embodiments, the environment 100 may comprise a further TRP serving the terminal device 120 and/or another terminal device.
In the environment 100, the terminal device 120 may communicate with the Spcell 101 provided by the network device 130 via the TRP 105 (also referred as “a first TRP 105” in the following) and the TRP 110 (also referred as “a second TRP 110” in the following) . For example, the terminal device 120 may communicate with the Spcell 101 via a beam 131-1/131-2/131-3 (collectively referred to as “first beam set 131” ) provided by the first TRP 105 and a beam 141-1/141-2/141-3 (collectively referred to as “second beam set 141” ) provided by the second TRP 110. Meanwhile, the first TRP 105 transmits a first set of reference signals associated with the first beam set 131 to the terminal device 120, and the second TRP 110 transmits a second set of reference signals for second beam failure detection associated with the second beam set 141 to the terminal device 120, each of the sets of reference signals comprises reference signal associated with individual beam of this set of reference signals, for example, the first set of reference signals comprises one or more reference signals associated with one or more of the beams 131-1, 131-2 and 131-3, respectively.
In some embodiments, the reference signal may be Beam Failure Detection (BFD) -Reference Signal (RS) . Therefore, the set of reference signals (e.g., the first or the second set of reference signals) may be a set of BFD-RS. In some embodiments, the first set of reference signals and second set of reference signals are associated with the Spcell 101.
A reference signal for BFD can be any suitable references signals. In some embodiments, the reference signal may be a Synchronization Signal Block (SSB) . In some embodiments, the reference signal may be a Channel State Information Reference Signal (CSI-RS) .
In some embodiments, a set of reference signals, e.g., the first or the second set of reference signals, may comprise one or more reference signals. In some embodiments, the terminal device 120 may detect references signals in the first set of reference signals to determine the occurrence of a beam failure for the first TRP 105 and may detect references signals in the second set of reference signals to determine the occurrence of a beam failure for the second TRP 110.
It is to be understood that the terminal device 120 may also communicate with the Spcell 101 via more than two TRPs. In some embodiments, a further beam set is provided by a further TRP, in addition to the first and second TRPs 105 and 110. Similarly, the further TRP also transmits a set of reference signals associated with the further beam set.
The communications in the environment 100 may follow any suitable communication standards or protocols, which are already in existence or to be developed in the future, such as Universal Mobile Telecommunications System (UMTS) , long term evolution (LTE) , LTE-Advanced (LTE-A) , the fifth generation (5G) New Radio (NR) , Wireless Fidelity (Wi-Fi) and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employs any suitable communication technologies, including, for example, Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiplexing (OFDM) , time division multiplexing (TDM) , frequency division multiplexing (FDM) , code division multiplexing (CDM) , Bluetooth, ZigBee, and machine type communication (MTC) , enhanced mobile broadband (eMBB) , massive machine type communication (mMTC) , ultra-reliable low latency communication (URLLC) , Carrier Aggregation (CA) , Dual Connection (DC) , and New Radio Unlicensed (NR-U) technologies.
FIG. 2 illustrates a flowchart of an example method implemented at a terminal device 120 in accordance with some embodiments of the present disclosure. For purpose of discussion, the flowchart 200 will be described with reference to FIG. 1.
Although some embodiments of the present disclosure are described with reference to two TRPs, i.e., the first and second TRPs 105 and 110 within e.g. a Spell 101 provided by the network device 130, these embodiments are given only for the purpose of illustration and to help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the present disclosure. It is to be understood that the present disclosure described herein can be implemented in various manners other than those described below.
In some embodiments, a SpCell is configured with two sets of BFD RS. For ease of discussion, the set of BFD-RS corresponding to the first TRP 105 may be referred to as the first set of BFD-RS, while the set of BFD-RS corresponding to the second TRP 110 may be referred to as the second set of BFD-RS. The beam failure corresponding to the first set of BFD-RS may be referred to as the first beam failure, while the beam failure corresponding to the second set of BFD-RS may be referred to as the second beam failure.
At 210, the terminal device 120 initiates a random access procedure for BFR for a first beam failure of a first set of BFD RS and/or the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure. In other words, the random access procedure may be triggered when the second beam failure is further detected after the first beam failure was already indicated to the network device but not successfully completed.
In some embodiments, BFR information of the first BFR for the first beam failure may be carried by Enhanced BFR MAC CE, or Truncated Enhanced BFR MAC CE which contains BFR information for the first set of BFD-RS of e.g. a special Cell, SpCell. The Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE are identified by a MAC sub-header with extended Logical Channel ID, eLCID. The MAC CE may further comprise a plurality of fields corresponding different cells. Fields associated with the SpCell 101 may be used to carry the BFR information.
Only for illustration purposes, example formats of the SpCell BFR MAC CE are now described in detail with reference to Figs. 4a and 4b. Fig. 4a illustrates an example of Enhanced BFR and Truncated Enhanced BFR MAC CE with one octet Ci field and Fig. 4b illustrates another example of Enhanced BFR and Truncated Enhanced BFR MAC CE with four octet Ci field. When the terminal device is configured with a number of cells less not more than 8, it may use the format illustrated in Fig. 4a; and if the number of cells is higher than 8, it may use the format illustrated in Fig. 4b.
As illustrated, the Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE have a variable size. They include a SP field, Ci bitmap (single octet or four octets) , Sj bitmap (0 to 4 octets) , and beam failure recovery information i.e. octets containing candidate beam availability indication (AC) for BFD-RS set (s) of SpCell configured with two BFD-RS sets, and in ascending order based on ServCellIndex.
The SP field of BFR MAC CE indicates beam failure detection for the SpCell of this MAC entity and the presence of octet (s) and may contain the AC field if the SpCell is configured with multiple BFD-RS sets.
The Ci field (such as, C ₁-C ₇ bits or C ₁ to C ₃₁ bits) indicates the index of the failed Cell, and contains AC field whether a candidate beam is available and the candidate beam index (such as, Candidate RS ID field, if any) in the canditebeam-rs-list (such as, a list of candidates beam indexes that are either SSB and/or CSI-RS indexes) .
The Sk field of BFR MAC CE corresponds to the kth Serving Cell for which SP/Ci field is set to 1 and is configured with two BFD-RS sets. This field indicates whether beam failure is detected for one or both BFD-RS sets and presence of one or two octets containing the AC field of the Serving Cell.
The terminal device may indicate candidate beams are available in AC filed and indicates candidate beams or Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE, one octet Sk bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/Ci field set to 1 is greater than 0 and less than 9, as shown in Fig 4a; a four octets Sk bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/Ci field set to 1 is greater than 24, as shown in Fig 4b; Sk bitmap is not included if the total number of Serving Cells configured with two BFD-RS sets for which SP/Ci field is set to 1 is zero.
At 220, the terminal device 120 receives a response of the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure. In other words, the network device receives the report of the first beam failure and provides a response to indicate the terminal device the first BFR is successfully completed.
In some embodiments, the response to the first BFR for the first beam failure may comprise a Physical downlink control channel, PDCCH, information addressed to Cell-Radio Network Temporary Identity, C-RNTI. The PDCCH information may indicate an uplink grant for a new transmission for a Hybrid Automatic Repeat request, HARQ, process used for the first transmission of the Enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE. In some embodiments, if such a PDCCH is received, consider the BFR procedure successfully completed.
At 230, the terminal device 120 stops the random access procedure upon receipt of the response to the BFR for the first beam failure.
In some embodiment, the terminal device 120 may trigger a second BFR for the second beam failure after stopping the random access procedure, wherein BFR information of the second BFR includes an enhanced BFR MAC CE, or a truncated enhanced BFR MAC CE which contains BFR information for the second beam failure The second BFR triggered for the second failed BFD-RS set remains pending and will be transmitted in subsequent uplink transmission following the procedure of only one set failure case, i.e. the BFR for the second beam failure can be transmitted on a beam associated with the first set of BFD RS In some embodiment, the terminal device 120 trigger a scheduling request for the second BFR for the second beam failure after stopping the random access procedure.
In some embodiments, the random access procedure can be stopped unconditionally upon receipt of the response to the BFR for the first beam failure.
In some embodiments, when the response to the BFR for the first beam failure is received, the terminal device may further determine whether to stop the random access procedure based on the status or stages of the random access procedure.
In some embodiment, the terminal device 120 may further determine whether MsgA or Msg3 for carrying the beam failure recovery information in the random access procedure has been built or not upon receipt of the response to the first BFR for the first beam failure. The terminal device may stop the random access procedure when the MsgA or Msg3 has not been built. On the other hand, when the MsgA or Msg3 has been built, the terminal device may continue the random access procedure.
In some embodiment, the terminal device 120 may further determine whether MsgA or Msg3 for carrying the beam failure recovery information in the random access procedure has been transmitted or not upon receipt of the response to the first BFR for the first beam failure. The terminal device may stop the random access procedure when the MsgA or Msg3 has not been transmitted. On the other hand, when the MsgA or Msg3 has been transmitted, the terminal device may continue the random access procedure.
In some embodiment, the terminal device 120 may stop the random access procedure when a response to the first BFR for the first beam failure is received, after message A (MsgA) or message 3 (Msg3) for carrying BFR information in the random access procedure has been built or transmitted.
In some embodiment, the terminal device 120 may include BFR information for both the first beam failure and the second beam failure in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within MsgA or Msg3 in the random access procedure when building the Msg A or Msg3 if no response to the first BFR for the first beam failure is received. For example, the terminal device 120 may trigger an Enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE which contains BFR information for the first set of BFD-RS for the first beam failure associated with the first set of BFD RS. In such a case, the terminal device 120 may include, when building the MsgA and Msg3, enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE for the first beam failure within the MsgA and Msg3, in addition to BFR information for the second beam failure.
FIG. 3 illustrates a flowchart of another example method implemented at a terminal device 120 in accordance with some embodiments of the present disclosure. For purpose of discussion, the flowchart 300 will be described with reference to FIG. 1.
At 310, the terminal device 120 may initiate a random access procedure for BFR for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and/or the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure. In other words, the random access procedure may be triggered when the second beam failure is further detected after the first beam failure was already indicated to the network device but not successfully completed.
At 320, the terminal device 120 may include BFR information for both the first beam failure and the second beam failure in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within the MsgA or Msg3 in the random access procedure.
As mentioned above with reference to Figs. 4s and 4b. BFR information can be carried within fields associated with SPcell in the Enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE.
For example, the terminal device 120 may trigger an Enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE which contains BFR information for the first set of BFD-RS for the first beam failure. In such a case, the terminal device 120 may include when building the MsgA and Msg3, enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE for the first beam failure within the MsgA and Msg3, in addition to BFR information for the second beam failure.
In some embodiments, BFR information for the first beam failure and/or the second beam failure can be included in MsgA or MSG3 unconditionally when building the MsgA or MSG3.
In some embodiments, the terminal device may determine whether to include BFR information for the first beam failure or the second beam failure based on status of the first beam failure recovery and/or status of the random access procedure.
In some embodiments, the terminal device 120 may determine whether BFR of the first beam and the second beam are successfully completed, before building of the MsgA or Msg3. when neither of the first beam and the second beam is successfully completed, the terminal device 120 may include BFR information for both the first beam and the second beam in MSG A or MSG3 in the random access procedure.
In some embodiments, the terminal device 120 may include the BFR information for both the first beam failure and the second beam failure in the MSGA or MSG3 in the random access procedure when any BFR for the first beam failure or the second beam failure is not successfully completed.
In some embodiments, the terminal device 120 may trigger second Enhanced BFR Media Access Control Control Element, MAC CE, or Truncated Enhanced BFR MAC CE which contains BFR information for the first beam failure of the first set of BFD RS to include in the message A (MsgA) or message 3 (Msg3) before building of the MsgA or Msg3.
In some embodiments, the terminal device 120 may include the BFR information for both the first beam failure and the second beam failure in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within the MSG A or MSG3 in the random access procedure when any BFR for the first beam failure or the second beam failure is successfully completed but no suitable candidate beam was indicated.
In some embodiments, the terminal device 120 may include the BFR information for both the first beam failure and the second beam failure in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within the MSG A or MSG3 in the random access procedure when the first BFR for the first beam failure was provided but is not acknowledged and no suitable candidate beam was indicated.
In some embodiments, the terminal device 120 may include a BFR information for only the second beam failure in the MsgA or Msg3 in the random access procedure when a response to the first BFR for the first beam failure is already received before building of the MsgA or Msg3, wherein the response indicates a successful completion of the first BFR for the first beam failure.
In some embodiments, the terminal device 120 may continue the random access procedure regardless of any response to the first BFR for the first beam failure.
In some embodiments, the terminal device 120 may stop the random access procedure upon receipt of the response to the first BFR for the first beam failure before building or transmitting of the MsgA or Msg3, wherein the response indicates the success completion of the first BFR for the first beam failure.
In some embodiments, the terminal device 120 may continue the random access procedure upon receipt of the response to the first BFR for the first beam failure after building or transmitting of the MsgA or Msg3, wherein the response indicates the success completion of the first BFR for the first beam failure.
In some embodiments, the BFR information for both the first beam failure and the second beam failure may be included in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within in MsgA or message 3 Msg3 as illustrated in Figs. 4a and 4b.
FIG. 5 is a simplified block diagram of a device 500 that is suitable for implementing embodiments of the present disclosure. The device 500 may be provided to implement the communication device, for example the terminal device 120, the network device 130 as shown in Fig. 1. As shown, the device 500 may include one or more processors 510, one or more memories 520 coupled to the processor 510, and one or more communication modules 540 coupled to the processor 510.
The communication module 540 is for bidirectional communications. The communication module 540 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.
The processor 510 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.
The memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 524, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 522 and other volatile memories that will not last in the power-down duration.
A computer program 530 includes computer executable instructions that are executed by the associated processor 510. The program 530 may be stored in the ROM 524. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 522.
The embodiments of the present disclosure may be implemented by means of the program 530 so that the device 500 may perform any process of the disclosure as discussed with reference to Figs. 2 to 4b. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.
In some embodiments, the program 530 may be tangibly contained in a computer readable medium which may be included in the device 500 (such as in the memory 520) or other storage devices that are accessible by the device 500. The device 500 may load the program 530 from the computer readable medium to the RAM 522 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.
Fig. 6 shows an example of the computer readable medium 600 in form of CD or DVD. The computer readable medium has the program 530 stored thereon.
Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 200 and 300 as described above with reference to Figs. 2-4b. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.
Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.
The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.
Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A terminal device, comprising:

at least one processor; and

at least one memory including computer program codes;

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to:

initiate a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure;

receive a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; and

stop the random access procedure upon receipt of the response to the first BFR for the first beam failure.
The terminal device of claim 1, wherein the terminal device is further caused to:

trigger a second BFR for the second beam failure after stopping the random access procedure,

wherein BFR information of the second BFR includes an enhanced BFR Medium Access Control Control Element, MAC CE, or a truncated enhanced BFR MAC CE which contains BFR information for the second beam failure.
The terminal device of claim 2, wherein the terminal device is further caused to:

trigger a scheduling request for the second BFR for the second beam failure after stopping the random access procedure.
The terminal device of any of claims 1 to 4, wherein the terminal device is further caused to:

determine whether message A (MsgA) or message 3 (Msg3) for carrying BFR information in the random access procedure has been built or not upon receipt of the response to the first BFR for the first beam failure,

wherein the stopping the random access procedure comprises stopping the random access procedure when the Msg A or Msg3 has not been built.
The terminal device of any of claims 1 to 5, wherein the terminal device is further caused to:

determine whether MsgA or Msg3 for carrying the BFR information in the random access procedure has been transmitted or not upon receipt of the response to the first BFR for the first beam failure,

wherein the stopping the random access procedure comprises stopping the random access procedure when the MsgA or Msg3 has not been transmitted.
The terminal device of any of claims 1 to 5, wherein the stopping the random access procedure comprises:

stop the random access procedure when a response to the first BFR for the first beam failure is received, after MsgA or Msg3 for carrying BFR information in the random access procedure has been built or transmitted.
The terminal device of any of claims 1 to 6, wherein the terminal device is further caused to:

include BFR information for both the first beam failure and the second beam failure in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within the MsgA or Msg3 in the random access procedure when building the Msg A or Msg3 if no response to the first BFR for the first beam failure is received.
The terminal device of any of Claims 1 to 7, wherein BFR information of the first BFR for the first beam failure comprises: Enhanced BFR MAC CE, or Truncated Enhanced BFR MAC CE which contains BFR information for the first set of BFD-RS of a special Cell, SpCell.
The terminal device of any of Claims 1 to 8, wherein the response to the first BFR for the first beam failure comprises a Physical downlink control channel, PDCCH, information addressed to Cell-Radio Network Temporary Identity, C-RNTI, indicating an uplink grant for a new transmission for a Hybrid Automatic Repeat request, HARQ, process used for the first transmission of the Enhanced BFR MAC CE or Truncated Enhanced BFR MAC CE as a response to the first BFR for the first beam failure.
A terminal device, comprising:

at least one processor; and

at least one memory including computer program codes;

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to:

initiate a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and

include BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
The terminal device of claims 8, where the terminal device is further caused to:

trigger a second Enhanced BFR Media Access Control Control Element, MAC CE, or Truncated Enhanced BFR MAC CE which contains BFR information for the first beam failure of the first set of BFD RS to include in the MsgA or Msg3 before building of the MsgA or Msg3.
The terminal device of claim 8, where the including BFR information comprise:

including the BFR information for both the first beam failure and the second beam failure in the Msg A or Msg3 in the random access procedure when any BFR for the first beam failure or the second beam failure is not successfully completed.
The terminal device of any of claims 8 to 10, wherein the including BFR information comprises:

including the BFR information for both the first beam failure and the second beam failure in the MSG A or MSG3 in the random access procedure when any BFR for the first beam failure or the second beam failure is successfully completed but no suitable candidate beam was indicated.
The terminal device of claims 8 to 11, wherein the including BFR information comprises:

including the BFR information for both the first beam failure and the second beam failure in the MSG A or MSG3 in the random access procedure when the first BFR for the first beam failure was provided but is not acknowledged and no suitable candidate beam was indicated.
The terminal device any of claims 8 to 12, wherein the including BFR information comprises:

including a BFR information for only the second beam failure in the MsgA or Msg3 in the random access procedure when a response to the first BFR for the first beam failure is already received before building of the MsgA or Msg3, wherein the response indicates a successful completion of the first BFR for the first beam failure.
The terminal device of claims 8 to 13, wherein the terminal device is further caused to:

continue the random access procedure regardless of any response to the first BFR for the first beam failure.
The terminal device of claims 8 to 13, wherein the terminal device is further caused to:

stop the random access procedure upon receipt of the response to the first BFR for the first beam failure before building or transmitting of the MsgA or Msg3, wherein the response indicates the successful completion of the first BFR for the first beam failure.
The terminal device of claim 15, wherein the terminal device is further caused to:

continue the random access procedure upon receipt of the response to the first BFR for the first beam failure after building or transmitting of the MsgA or Msg3, wherein the response indicates the successful completion of the first BFR for the first beam failure.
The terminal device of any of Claims 1 to 18, wherein the BFR information for both the first beam failure and the second beam failure is included in enhanced BFR MAC CE, or Truncated enhanced BFR MAC CE within the MsgA or Msg3.
A method at a terminal device, comprising:

initiating a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure;

receiving a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; and

stopping the random access procedure upon receipt of the response to the first BFR for the first beam failure.
A method at a terminal device, comprising:

initiating a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and

including BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
An apparatus comprising:

means for initiating a random access procedure for beam failure recovery, BFR, for a first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure;

means for receiving a response to the first BFR for the first beam failure, wherein the response indicates a successful completion of the first BFR for the first beam failure; and

means for stopping the random access procedure upon receipt of the response to the first BFR for the first beam failure.
An apparatus comprising:

means for initiating a random access procedure for beam failure recovery, BFR, for the first beam failure of a first set of beam failure detection reference signals, BFD RS, and the second beam failure of a second set of BFD RS, wherein a first BFR for the first beam failure was already triggered before the second beam failure; and

means for including BFR information for both the first beam failure and the second beam failure in the message A (MsgA) or message 3 (Msg3) in the random access procedure.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of claim 20 or 21.