Patent Publication Number: US-2023146999-A1

Title: Time domain resource allocation for multicast broadcast service

Description:
RELATED APPLICATION 
     This application claims priority from PCT Application PCT/CN2021/128929, filed on Nov. 5, 2021, which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a method, device and computer readable storage medium of communication in time domain resource allocation (TDRA) for multicast broadcast service (MBS). 
     BACKGROUND 
     With development of a new radio (NR) multicast technology, third generation partnership project (3GPP) is currently defining mechanisms for enabling the delivery of multicast traffic and/or broadcast traffic to a multitude of terminal devices. One key aim is to define group scheduling mechanisms that enable the multicast traffic and/or broadcast traffic to be scheduled using common data channel resources, while maintaining maximum commonalities with the currently defined unicast scheduling and operation mechanisms. 
     Currently, it is agreed that downlink control information (DCI) formats 1_0 and 1_1 used for scheduling unicast traffic, could be used as baseline for scheduling multicast traffic physical downlink shared channel (PDSCH) resources. A TDRA field within DCI informs the terminal device which field within a pre-defined set of TDRA lists should be applied. For NR MBS, it is still to be studied how to apply an appropriate configuration for determining which TDRA list to utilize. 
     SUMMARY 
     In general, example embodiments of the present disclosure provide a solution for enabling a terminal device to select the applicable time domain resource allocation table for MBS. 
     In a first aspect, there is provided a first device. The first device comprises: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to: receive, from a second device, downlink control information comprising a time domain resource allocation field; determine, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and apply, based on the time domain resource allocation list, the time domain resource allocation field for reception of the traffic from the second device. 
     In a second aspect, there is provided a second device. The second device comprises: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to: transmit, to a first device, downlink control information comprising a time domain resource allocation field; determine, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and apply, based on the time domain resource allocation list, the time domain resource allocation field for transmission of the traffic to the first device. 
     In a third aspect, there is provided a method of communication. The method comprises: receiving, at a first device and from a second device, downlink control information comprising a time domain resource allocation field; determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and applying, based on the time domain resource allocation list, the time domain resource allocation field for reception of the traffic from the second device. 
     In a fourth aspect, there is provided a method of communication. The method comprises: transmitting, at a second device and to a first device, downlink control information comprising a time domain resource allocation field; determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and applying, based on the time domain resource allocation list, the time domain resource allocation field for transmission of the traffic to the first device. 
     In a fifth aspect, there is provided an apparatus of communication. The apparatus comprises: means for receiving, at a first device and from a second device, downlink control information comprising a time domain resource allocation field; means for determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and means for applying, based on the time domain resource allocation list, the time domain resource allocation field for reception of the traffic from the second device. 
     In a sixth aspect, there is provided an apparatus of communication. The apparatus comprises: means for transmitting, at a second device and to a first device, downlink control information comprising a time domain resource allocation field; means for determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and means for applying, based on the time domain resource allocation list, the time domain resource allocation field for transmission of the traffic to the first device. 
     In a seventh aspect, there is provided a non-transitory means for computer readable medium. The non-transitory computer readable medium comprises program instructions for causing an apparatus to perform the method according to the third aspect. 
     In an eighth aspect, there is provided a non-transitory computer readable medium. The non-transitory computer readable medium comprises program instructions for causing an apparatus to perform the method according to the 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 example embodiments of the present disclosure may be implemented; 
         FIG.  2    illustrates a diagram illustrating a process of communication according to some embodiments of the present disclosure; 
         FIG.  3 A  illustrates a flowchart illustrating a method of determining a TDRA list according to example embodiments of the present disclosure; 
         FIG.  3 B  illustrates a flowchart illustrating another method of determining a TDRA list according to example embodiments of the present disclosure; 
         FIG.  3 C  illustrates a flowchart illustrating still another method of determining a TDRA list according to example embodiments of the present disclosure; 
         FIG.  4    illustrates a flowchart illustrating a method of communication implemented at a first device according to example embodiments of the present disclosure; 
         FIG.  5    illustrates a flowchart illustrating a method of communication implemented at a second device according to example embodiments of the present disclosure; 
         FIG.  6    illustrates a simplified block diagram of an apparatus that is suitable for implementing example embodiments of the present disclosure; and 
         FIG.  7    illustrates a block diagram of an example computer readable medium in accordance with example 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 standard, such as fifth generation (5G) systems, fifth generation-advanced (5G-Advanced) systems, 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 protocol, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) new radio (NR) communication protocols, and/or any other protocols either currently known or to be developed in the future. 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. A RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY). A relay node may correspond to DU part of the IAB node. 
     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), a Mobile Terminal (MT), 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 (IoT) 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. The terminal device may also correspond to Mobile Termination (MT) part of the integrated access and backhaul (IAB) node (a.k.a. a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably. 
     The term “multicast traffic” as used herein implies traffic delivered to a group of users interested in receiving the traffic, and also implies data that is sent over the air and received by all users interested in receiving the traffic. In other words, the multicast traffic as used herein may also cover both multicast and broadcast services. In the following description, the terms “multicast traffic”, “multicast service”, “broadcast traffic”, “broadcast service” and “multicast broadcast service (MBS)” may be used interchangeably. 
     As known, DCI formats 1_0, 1_1 and 1_2 are used by a network device to inform a terminal device about the PDSCH resources where downlink data would be scheduled. Currently these formats have been defined for unicast traffic, which implies that the network device would utilize either of these DCI formats to inform a terminal device about upcoming scheduled downlink information over PDSCH using a physical downlink control channel (PDCCH) specific to the terminal device. As mentioned above, it is agreed that DCI formats 1_0 and 1_1 could be used as baseline for scheduling multicast traffic PDSCH resources, with the use of a common identifier—called group-common radio network temporary identifier (G-RNTI) to scramble the control information. This enables a group of users to receive the downlink control information. 
     In this case, the network device would be using group-common PDCCH resources for sending the DCI with cyclic redundancy check (CRC) scrambled using a group-common RNTI value which is possibly configured by higher layers. These PDCCH resources would be configured using a new type of search space set which could be dedicated to schedule the control information for multicast and/or broadcast traffic. The search space sets are called Type-X, Type- 3 A or multicast or broadcast search space sets. 
     A TDRA field within DCI informs a terminal device which field within a pre-defined set of TDRA lists should be applied. Based on certain priorities, currently different higher layer configurations such as PDSCH-Config or PDSCH-ConfigCommon are applied for computing which TDRA list should be used by the terminal device to interpret the TDRA field. For NR MBS, a higher layer configuration PDSCH-Config-Multicast is expected to be applied. 
     However, PDSCH-Config-Multicast is a parameter configured using RRC once a terminal device establishes a RRC connection with a network device. For a terminal device in an idle or inactive state, currently there are no such configurations provided, since the terminal device does not have an active RRC connection with the network device. This leads to an issue for Type-X common search space (CSS) as shown in Table 1, where if a UE is simultaneously configured with multicast and broadcast traffic with two different G-RNTIs, the UE cannot choose a TDRA table (also referred to as TDRA list herein) which could be applied to multicast and broadcast DCIs. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 An issue in applicable PDSCH time domain resource allocation for DCI formats 1_0 and 1_1 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 SS/PBCH 
                 PDSCH- 
                   
                   
               
               
                   
                   
                 block and 
                 ConfigCommon 
                 PDSCH-Config 
               
               
                   
                   
                 CORESET 
                 includes pdsch- 
                 includes pdsch- 
                 PDSCH time 
               
               
                   
                 PDCCH 
                 multiplexing 
                 TimeDomainAl- 
                 TimeDomainAl- 
                 domain resource 
               
               
                 RNTI 
                 search space 
                 pattern 
                 locationList 
                 locationList 
                 allocation to apply 
               
               
                   
               
               
                 SI-RNTI 
                 Type0 common 
                 1 
                 — 
                 — 
                 Default A for normal CP 
               
               
                   
                   
                 2 
                 — 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 — 
                 — 
                 Default C 
               
               
                 SI-RNTI 
                 Type0A common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                   
                   
                 2 
                 No 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 RA-RNTI, 
                 Type1 common 
                 1, 2, 3 
                 No 
                 — 
                 Default A 
               
               
                 MSGB-RNTI, 
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                 TC-RNTI 
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 P-RNTI 
                 Type2 common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                   
                   
                 2 
                 No 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 G-RNTI, 
                 Type X common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                 GS-RNTI 
                   
                 2 
                 No 
                 — 
                 Default B 
               
               
                 (Option-1) 
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 ? 
                 = 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 ????? 
               
               
                 C-RNTI, 
                 Any common 
                 1, 2, 3 
                 No 
                 — 
                 Default A 
               
               
                 MCS-C- 
                 search space 
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                 RNTI, 
                 associated with 
                   
                   
                   
                 locationList provided in 
               
               
                 CS-RNTI 
                 CORESET 0 
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 C-RNTI, 
                 Any common 
                 1, 2, 3 
                 No 
                 No 
                 Default A 
               
               
                 MCS-C- 
                 search space not 
                 1, 2, 3 
                 Yes 
                 No 
                 pdsch-TimeDomainAl- 
               
               
                 RNTI, 
                 associated with 
                   
                   
                   
                 locationList provided in 
               
               
                 CS-RNTI, 
                 CORESET 0 
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 G-RNTI, 
                 UE specific 
                   
                   
                   
                 (Note 1) 
               
               
                 G-CS- 
                 search space 
                 1, 2, 3 
                 No/Yes 
                 Yes 
                 pdsch-TimeDomainAl- 
               
               
                 RNTI 
                   
                   
                   
                   
                 locationList provided in 
               
               
                 (Option-2) 
                   
                   
                   
                   
                 PDSCH-Config 
               
               
                   
               
               
                 (Note 1): 
               
               
                 For G-RNTI and G-CS-RNTI PDSCH time domain resource allocation should be applied using the parameters provided in PDSCH-Config-Multicast, if configured 
               
            
           
         
       
     
     Currently, Type-X CSS is a new common search space defined for broadcast and multicast. For multicast, it is agreed that for CSS of group-common PDCCH of point-to-multipoint (PTM) scheme 1—whereby a group-common PDCCH is used to schedule group-common PDSCH for multicast in a RRC_CONNECTED state, a Type-X CSS is supported. The monitoring priority of Type-X CSS is determined based on the search space set indexes of the Type-x CSS set and UE-specific search space (USS) sets, regardless of which DCI format of group-common PDCCH is configured in the Type-X CSS. 
     As shown in Table 1 for Type-X CSS, the issue to be addressed is how to identify an appropriate TDRA list to be utilized for interpreting a TDRA field in DCI while simultaneously receiving multicast and broadcast traffic, using G-RNTI. Currently, the UE can either use option-1 or option-2 shown in the table. Based on the currently proposed specification update, in case PDSCH-Config-Multicast is not configured, a terminal device in a connected state receiving multicast/unicast and broadcast traffic might utilize a TDRA list provided in PDSCH-Config, but a terminal device receiving only broadcast traffic would utilize a TDRA list provided in PDSCH-ConfigCommon, leading to two different TDRA tables being used which in turn leads to misinterpretation of the TDRA field received within the DCI. 
     In view of this, embodiments of the present disclosure provide an improved solution for communication. In the solution, a TDRA list is determined from a set of configurations for TDRA based on an identifier for scrambling DCI, a RRC state of a terminal device and a type of traffic configured for the terminal device. Then, a TDRA field in the DCI the TDRA list is applied in the TDRA list to determine a time domain resource for transmission or reception of the traffic. In this way, a terminal device in a connected state receiving multicast/unicast and broadcast traffic and a terminal device receiving only broadcast traffic may be enabled to interpret a common TDRA list to be used. Accordingly, a significant flexibility to schedule MBS may be provided with optimal functioning of the time domain resource allocation, and a significant complexity reduction to a terminal device may be provided. 
     Principles and implementations of the present disclosure will be described in detail below with reference to the figures. 
       FIG.  1    illustrates an example communication network  100  in which embodiments of the present disclosure can be implemented. As shown in  FIG.  1   , the network  100  includes a first device  110  and a second device  120  serving the first device  110 . It is to be understood that the number of the first and second devices as shown in  FIG.  1    are only for the purpose of illustration without suggesting any limitations. The network  100  may include any suitable number of first and second devices adapted for implementing embodiments of the present disclosure. In some embodiments, the first device  110  may be a terminal device, and the second device  120  may be a network device. 
     Merely for illustration purposes and without suggesting any limitations as to the scope of the present disclosure, some embodiments will be described in the context where the first device  110  is a terminal device and the second device  120  is a network device. It is to be understood that, in other embodiments, the first device  110  may be a network device and the second device  120  may be a terminal device. In other words, the principles and spirit of the present disclosure may be applied to both uplink and downlink transmissions. 
     As shown in  FIG.  1   , the first device  110  and the second device  120  may communicate with each other via a wireless communication channel. The communications within the network  100  may conform to any suitable standard including, but not limited to, LTE, LTE-evolution, LTE-advanced (LTE-A), wideband code division multiple access (WCDMA), code division multiple access (CDMA) and global system for mobile communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) or the sixth generation (6G) communication protocols. 
     In some scenarios, the second device  120  may transmit any of multicast traffic, unicast traffic and broadcast traffic to the first device  110 . For example, the second device  120  may transmit broadcast and multicast traffic to the first device  110 . In some scenarios, the second device  120  may transmit DCI to the first device  110  to schedule the traffic. The DCI may comprise a TDRA field. The first device  110  may interpret the TDRA field to determine a time domain resource, and receive the traffic based on the time domain resource. 
     Embodiments of the present disclosure provide a mechanism for applying or interpreting the TDRA field in an appropriate TDRA list so that terminal devices receiving different types of traffic have a common understanding of the TDRA field. This mechanism of the present disclosure is illustrated in a high-level flowchart as shown in  FIG.  2   . 
       FIG.  2    illustrates a flowchart illustrating a process  200  of communication according to some embodiments of the present disclosure. For convenience,  FIG.  2    will be described in connection with the example of  FIG.  1   . 
     As shown in  FIG.  2   , the second device  120  may transmit  210  a set of configurations for TDRA to the first device  110 . In some embodiments, the set of configurations may be a set of higher layer configurations such as a set of RRC configurations. Of course, any other suitable forms are also feasible. In some embodiments, the set of configurations may comprise at least one of the following: a PDSCH-Config-Multicast configuration, a PDSCH-ConfigCommon configuration, a PDSCH-Config configuration, default A, B or C tables. It is to be understood that any other suitable configurations existing or to be developed in future are also feasible. 
     Each of the configurations comprises a predetermined TDRA list. For example, PDSCH-Config-Multicast configuration comprises pdsch-TimeDomainAllocationList-Multicast. PDSCH-Config-Broadcast configuration comprises pdsch-TimeDomainAllocationList-Broadcast. PDSCH-Config configuration comprises pdsch-TimeDomainAllocationList. Of course, any other suitable forms are also feasible. 
     When traffic is to be transmitted, the second device  120  transmits  220  DCI comprising a TDRA field to the first device  110 . It is to be understood that the DCI may comprise any suitable additional fields, and the present disclosure does not limit this aspect. 
     Upon reception of the DCI, the first device  110  determines  230  a TDRA list from the set of configurations for TDRA based on at least one of the following: an identifier for scrambling the DCI, a RRC state of the first device  110 , or a type of traffic configured for the first device. In this way, different devices configured with the reception of different types of traffic have a common understanding of the TDRA field for multicast and broadcast. 
     In some embodiments, a search space set type may configure the resources where the DCI may be sent along with the identifiers used for scrambling the DCI. 
     In some embodiments, the identifier for scrambling the DCI may be an identifier used to scramble CRC of the DCI. For example, the identifier may be a radio network temporary identity (RNTI) such as cell-RNTI (C-RNTI), group-RNTI (G-RNTI), group-common configured scheduling-RNTI (G-CS-RNTI), or single-cell-RNTI (SC-RNTI). It is to be understood that these are merely examples, and any other suitable identifiers are also feasible. 
     In some embodiments, the RRC state of the first device  110  may be a connected state such as a RRC_CONNECTED state or mode. In some embodiments, the RRC state of the first device  110  may be an idle state such as a RRC_IDLE state or mode. In some embodiments, the RRC state of the first device  110  may be an inactive state such as a RRC_INACTIVE state or mode. 
     In some embodiments, the type of traffic may be at least one of multicast traffic, broadcast traffic or unicast traffic. 
     Upon determination of the TDRA list, the first device  110  applies  240  the TDRA field based on the TDRA list to determine a time domain resource for reception of the traffic. The applying of the TDRA field may be implemented in any suitable ways and the present disclosure does not limit this aspect. 
     As shown in  FIG.  2   , after the transmission of the DCI, the second device  120  also determines  250  the TDRA list from the set of configurations based on at least one of the identifier for scrambling the DCI, the RRC state of the first device  110 , or the type of traffic configured for the first device  110 . The operations of the determining  250  are similar as that of the determining  230 . 
     Upon determination of the TDRA list, the second device  120  also applies  260  the TDRA field based on the TDRA list to determine the time domain resource for transmission of the traffic. The operations of the applying  260  are similar as that of the applying  240 . The applying of the TDRA field may be implemented in any suitable ways and the present disclosure does not limit this aspect. 
     For illustration, some example embodiments for the determination of the TDRA list will be described in connection with Embodiments 1 to 3. 
     Embodiment 1 
     In this embodiment, the TDRA list is determined based on the identifier for scrambling the DCI, the radio resource control state of the first device  110  or the type of traffic configured for the first device  110 . This will be described with reference to  FIG.  3 A . 
       FIG.  3 A  illustrates a flowchart illustrating a method  300 A of determining a TDRA list according to example embodiments of the present disclosure. The method  300 A can be implemented at the first device  110  or the second device  120  shown in  FIG.  1   . For the purpose of discussion, the method  300 A will be described in connection with the first device  110  in  FIG.  1   . It is to be understood that the method  300 A may also be implemented at the second device  120 . It is also to be understood that the method  300 A may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. 
     As shown in  FIG.  3 A , at block  301 , the first device  110  may determine whether the first device  110  is in a connected state. If the first device  110  is in the connected state, the process proceeds to block  302 . 
     At block  302 , the first device  110  may determine whether the type of traffic is at least broadcast and multicast traffic. For example, the first device  110  may determine whether the first device  110  is configured to receive broadcast and multicast traffic. In another example, the first device  110  may determine whether the first device  110  is configured to receive broadcast, multicast and unicast traffic. If the type of traffic is broadcast and multicast traffic, or if the type of traffic is broadcast, multicast and unicast traffic, the process  300 A proceeds to block  303 . 
     At block  303 , the first device  110  may determine whether a PDSCH-Config-Multicast configuration (for convenience, also referred to as a first configuration herein) is configured for the first device  110 . If the PDSCH-Config-Multicast configuration is configured, the process  300 A proceeds to block  304 . 
     At block  304 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. 
     If the identifier is a predetermined identifier, the process  300 A proceeds to block  305 . At block  305 , the first device  110  may determine the TDRA list from the PDSCH-Config-Multicast configuration. For example, the first device  110  may determine, as the TDRA list, a TDRA list such as pdsch-TimeDomainAllocationList-Multicast provided in the PDSCH-Config-Multicast configuration. 
     Return to block  303 , if determining that the PDSCH-Config-Multicast configuration is not configured, the process  300 A proceeds to block  306 . At block  306 , the first device  110  may determine whether a PDSCH-Config-Common configuration (for convenience, also referred to as a second configuration herein) is configured for the first device  110 . If the PDSCH-Config-Common configuration is configured, the process  300 A proceeds to block  307 . 
     At block  307 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. 
     If the identifier is a predetermined identifier, the process  300 A proceeds to block  308 . At block  308 , the first device  110  may determine the TDRA list from the PDSCH-Config-Common configuration. 
     Return to block  306 , if determining that the PDSCH-Config-Common configuration is not configured, the process  300 A proceeds to block  309 . At block  309 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. 
     If the identifier is a predetermined identifier, the process  300 A proceeds to block  310 . At block  310 , the first device  110  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. 
     If the predetermined identifier is associated with multicast traffic, the process  300 A proceeds to block  311 . At block  311 , the first device  110  may determine the TDRA list from a default A table (for convenience, also referred to as a third configuration herein). 
     If the predetermined identifier is associated with broadcast traffic, the process  300 A proceeds to block  312 . At block  312 , the first device  110  may determine the TDRA list from a set of default A, B and C tables (for convenience, also referred to as a fourth configuration herein) based on a synchronization signal (SS)/physical broadcast channel (PBCH) block and control resource set (CORESET) multiplexing pattern. For example, the first device  110  may determine the TDRA list from the default A, B or C table based on a SS/PBCH block and CORESET multiplexing pattern. 
     Embodiment 2 
     This embodiment is a modification of Embodiment 1. This embodiment provides an alternative for blocks  306  to  312  of  FIG.  3 A . In this embodiment, the first device  110  may receive, from the second device  120 , an indication indicating whether a PDSCH-Config-Common configuration (i.e., the second configuration) or a PDSCH-Config configuration (for convenience, also referred to as a fifth configuration herein) is used for the determination of the TDRA list. The indication may be carried in any suitable forms. 
     The details of this embodiment will be described with reference to  FIG.  3 B .  FIG.  3 B  illustrates a flowchart illustrating another method  300 B of determining a TDRA list according to example embodiments of the present disclosure. The method  300 B can be implemented at the first device  110  or the second device  120  shown in  FIG.  1   . For the purpose of discussion, the method  300 B will be described in connection with the first device  110  in  FIG.  1   . It is to be understood that the method  300 B may also be implemented at the second device  120 . It is also to be understood that the method  300 B may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. 
     If determining at block  303  in  FIG.  3 A  that the PDSCH-Config-Multicast configuration (i.e., the first configuration) is not configured, the process  300 B may start. 
     As shown in  FIG.  3 B , at block  320 , the first device  110  may determine whether the PDSCH-Config-Common configuration or PDSCH-Config configuration is used based on the indication. If the PDSCH-Config-Common configuration is used, the process  300 B proceeds to block  321 . 
     At block  321 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. In some embodiments, the predetermined identifier may be associated with multicast traffic. In some embodiments, the predetermined identifier may be associated with broadcast traffic. 
     If the identifier is the predetermined identifier, the process  300 B proceeds to block  322 . At block  322 , the first device  110  may determine the TDRA list from the PDSCH-Config-Common configuration. In other words, if the first device  110  is not configured with PDSCH-Config-Multicast configuration, the first device  110  may apply a TDRA list provided in PDSCH-Config-Common configuration and apply it for only those DCIs with CRC scrambled using G-RNTI or G-CS-RNTI for multicast and broadcast. 
     Return to block  320 , if determining that the PDSCH-Config configuration is used, the process  300 B proceeds to block  323 . At block  323 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. 
     If the identifier is the predetermined identifier, the process  300 B proceeds to block  324 . At block  324 , the first device  110  may determine the TDRA list from the PDSCH-Config configuration. In other words, if the first device  110  is not configured with PDSCH-Config-Multicast configuration, the first device  110  may apply a TDRA list provided in PDSCH-Config configuration and apply it for only those DCIs with CRC scrambled using G-RNTI or G-CS-RNTI for multicast and broadcast. In some embodiments, the predetermined identifier may be associated with multicast traffic. In some embodiments, the predetermined identifier may be associated with broadcast traffic. 
     In this way, the TDRA list to be used may be determined in an optimal manner, with all the UEs receiving the multicast and broadcast traffic determining common values for the time domain resources where the data traffic would be scheduled. 
     Embodiment 3 
     This embodiment is another modification of Embodiment 1. This embodiment provides an alternative for blocks  304  to  305  of  FIG.  3 A . The details of this embodiment will be described with reference to  FIG.  3 C . 
       FIG.  3 C  illustrates a flowchart illustrating still another method  300 C of determining a TDRA list according to example embodiments of the present disclosure. The method  300 C can be implemented at the first device  110  or the second device  120  shown in  FIG.  1   . For the purpose of discussion, the method  300 C will be described in connection with the first device  110  in  FIG.  1   . It is to be understood that the method  300 C may also be implemented at the second device  120 . It is also to be understood that the method  300 C may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. 
     If determining at block  303  in  FIG.  3 A  that the PDSCH-Config-Multicast configuration (i.e., the first configuration) is configured, the process  300 C may start. 
     As shown in  FIG.  3 C , at block  330 , the first device  110  may determine whether the identifier is a predetermined identifier. In other words, the first device  110  may determine whether the DCI is scrambled by the predetermined identifier. For example, the first device  110  may determine whether CRC of the DCI is scrambled by the predetermined identifier. 
     In some embodiments, the predetermined identifier may be a G-RNTI. In some embodiments, the predetermined identifier may be a G-CS-RNTI. Of course, the predetermined identifier may adopt any other suitable forms. 
     If the identifier is the predetermined identifier, the process  300 C proceeds to block  331 . At block  331 , the first device  110  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. 
     If the predetermined identifier is associated with multicast traffic, the process  300 C proceeds to block  332 . At block  332 , the first device  110  may determine the TDRA list from the PDSCH-Config-Multicast configuration. 
     Return to block  331 , if the predetermined identifier is associated with broadcast traffic, the process  300 C proceeds to block  333 . At block  333 , the first device  110  may determine whether a PDSCH-Config-Broadcast configuration (for convenience, also referred to as a sixth configuration herein) is configured. 
     If the PDSCH-Config-Broadcast configuration is configured, the process  300 C proceeds to block  334 . At block  334 , the first device  110  may determine the TDRA list from the PDSCH-Config-Broadcast configuration. 
     Return to block  333 , if determining that the PDSCH-Config-Broadcast configuration is not configured, the process  300 C proceeds to block  335 . At block  335 , the first device  110  may determine whether a PDSCH-Config-Common configuration (i.e., the second configuration) is configured. 
     If the PDSCH-Config-Common configuration is configured, the process  300 C proceeds to block  336 . At block  336 , the first device  110  may determine the TDRA list from the PDSCH-Config-Common configuration. 
     If determining at block  335  that the PDSCH-Config-Common configuration is not configured, the process  300 C proceeds to block  337 . At block  337 , the first device  110  may determine the TDRA list from a set of default A, B and C tables (i.e., the fourth configuration) based on a SS/PBCH block and CORESET multiplexing pattern. For example, the first device  110  may determine the TDRA list from the default A, B or C table based on a SS/PBCH block and CORESET multiplexing pattern. 
     In this way, the TDRA list to be used may be determined in an optimal manner, with all the UEs receiving the multicast and broadcast traffic determining common values for the time domain resources where the data traffic would be scheduled. 
     According to embodiments of the present disclosure, Table 1 may be updated as Table 2 below. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 An example of applicable PDSCH time domain resource allocation for DCI formats 1_0 and 1_1 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 SS/PBCH 
                 PDSCH- 
                   
                   
               
               
                   
                   
                 block and 
                 ConfigCommon 
                 PDSCH-Config 
               
               
                   
                   
                 CORESET 
                 includes pdsch- 
                 includes pdsch- 
                 PDSCH time 
               
               
                   
                 PDCCH 
                 multiplexing 
                 TimeDomainAl- 
                 TimeDomainAl- 
                 domain resource 
               
               
                 RNTI 
                 search space 
                 pattern 
                 locationList 
                 locationList 
                 allocation to apply 
               
               
                   
               
               
                 SI-RNTI 
                 Type0 common 
                 1 
                 — 
                 — 
                 Default A for normal 
               
               
                   
                   
                   
                   
                   
                 CP 
               
               
                   
                   
                 2 
                 — 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 — 
                 — 
                 Default C 
               
               
                 SI-RNTI 
                 Type0A common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                   
                   
                 2 
                 No 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH- 
               
               
                   
                   
                   
                   
                   
                 ConfigCommon 
               
               
                 RA-RNTI, 
                 Type1 common 
                 1, 2, 3 
                 No 
                 — 
                 Default A 
               
               
                 MSGB-RNTI, 
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                 TC-RNTI 
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 P-RNTI 
                 Type2 common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                   
                   
                 2 
                 No 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 G-RNTI, 
                 Type X common 
                 1 
                 No 
                 — 
                 Default A 
               
               
                 GS-RNTI 
                 for broadcast 
                 2 
                 No 
                 — 
                 Default B 
               
               
                   
                   
                 3 
                 No 
                 — 
                 Default C 
               
               
                   
                   
                 1, 2, 3 
                 No/Yes 
                 Yes (PDSCH- 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                 Config- 
                 locationList provided in 
               
               
                   
                   
                   
                   
                 Broadcast) 
                 PDSCH-Config-Broadcast 
               
               
                   
                   
                 1, 2, 3 
                 No/Yes 
                 No 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 C-RNTI, 
                 Any common 
                 1, 2, 3 
                 No 
                 — 
                 Default A 
               
               
                 MCS-C- 
                 search space 
                 1, 2, 3 
                 Yes 
                 — 
                 pdsch-TimeDomainAl- 
               
               
                 RNTI, 
                 associated with 
                   
                   
                   
                 locationList provided in 
               
               
                 CS-RNTI 
                 CORESET 0 
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                 C-RNTI, 
                 Any common 
                 1, 2, 3 
                 No 
                 No 
                 Default A 
               
               
                 MCS-C- 
                 search space not 
                 1, 2, 3 
                 Yes 
                 No 
                 pdsch-TimeDomainAl- 
               
               
                 RNTI, 
                 associated with 
                   
                   
                   
                 locationList provided in 
               
               
                 CS-RNTI 
                 CORESET 0 
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                   
                 UE specific 
                 1, 2, 3 
                 No/Yes 
                 Yes 
                 pdsch-TimeDomainAl- 
               
               
                   
                 search space 
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-Config 
               
               
                 G-RNTI, 
                 Type-X common 
                 1, 2, 3 
                 No 
                 No 
                 pdsch-TimeDomainAl- 
               
               
                 G-CS- 
                 search space 
                   
                   
                   
                 locationList provided in 
               
               
                 RNTI 
                 for multicast 
                   
                   
                   
                 PDSCH-Config-Multicast 
               
               
                   
                   
                   
                   
                   
                 or if not configured 
               
               
                   
                   
                   
                   
                   
                 Default A 
               
               
                   
                   
                 1, 2, 3 
                 Yes 
                 No 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-ConfigCommon 
               
               
                   
                   
                 1, 2, 3 
                 No/Yes 
                 Yes 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-Config 
               
               
                   
                   
                 1, 2, 3 
                 No/Yes 
                 No/Yes 
                 pdsch-TimeDomainAl- 
               
               
                   
                   
                   
                   
                   
                 locationList provided in 
               
               
                   
                   
                   
                   
                   
                 PDSCH-Config-Multicast 
               
               
                   
               
            
           
         
       
     
     Corresponding to the above process described in  FIGS.  2  to  3 C , embodiments of the present disclosure provide methods of communication implemented at a first device and at a second device. These methods will be described below with reference to  FIGS.  4  to  5   . However, those skilled in the art would readily appreciate that the detailed description given herein with respect to these figures is for explanatory purpose as the present disclosure extends beyond theses limited embodiments. 
       FIG.  4    illustrates a flowchart of a method  400  of communication implemented at a first device according to example embodiments of the present disclosure. The method  400  can be implemented at the first device  110  shown in  FIG.  1   . For the purpose of discussion, the method  400  will be described with reference to  FIG.  1   . It is to be understood that method  400  may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. 
     As shown in  FIG.  4   , at block  410 , the first device  110  receives, from the second device  120 , DCI comprising a TDRA field. 
     At block  420 , the first device  110  determines, based on at least one of an identifier for scrambling the DCI, a RRC of the first device  110  or a type of traffic configured for the first device  110 , a TDRA list from a set of configurations for TDRA. 
     In some embodiments, the RRC state of the first device  110  may be one of a connected state, idle state and inactive sate. In some embodiments, the type of traffic is at least one of broadcast traffic, multicast traffic or unicast traffic. 
     In some embodiments, if the first device  110  is in a connected state and the type of traffic is at least broadcast and multicast traffic, the first device  110  may determine whether a first configuration (for example, PDSCH-Config-Multicast configuration) is configured for the first device  110 . If the first configuration is configured for the first device  110 , the first device  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine the TDRA list from the first configuration. 
     In some embodiments, if the first configuration is not configured for the first device  110 , the first device  110  may determine whether a second configuration (for example, PDSCH-Config-Common configuration) is not configured for the first device  110 . If the second configuration is configured for the first device  110 , the first device  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine the TDRA list from the second configuration. 
     In some embodiments, if the second configuration is not configured for the first device  110 , the first device  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. If the predetermined identifier is associated with multicast traffic, the first device  110  may determine the TDRA list from a third configuration (for example, default A table). If the predetermined identifier is associated with broadcast traffic, the first device  110  may determine the TDRA list from a fourth configuration (for example, a set of default A, B and C tables) based on a SS/PBCH block and CORESET multiplexing pattern. 
     In some embodiments, the first device  110  may receive, from the second device  120 , an indication indicating whether a second configuration (for example, PDSCH-Config-Common configuration) or a fifth configuration (for example, PDSCH-Config configuration) is used for the determination of the TDRA list. 
     In these embodiments, if the first configuration is not configured for the first device  110 , the first device  110  may determine, based on the indication, whether the second configuration or the fourth configuration is used. If the second configuration is used, the first device  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  120  may determine the TDRA list from the second configuration. In some embodiments, if the fifth configuration is used, the first device  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine the TDRA list from the fifth configuration. 
     In some embodiments, if the first device  110  is in a connected state and the type of traffic is at least broadcast and multicast traffic, the first device  110  may determine whether a first configuration (for example, PDSCH-Config-Multicast configuration) is configured for the first device  110 . If the first configuration is configured for the first device  110 , the first deice  110  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. If the predetermined identifier is associated with multicast traffic, the first device  110  may determine the TDRA list from the first configuration. If the predetermined identifier is associated with broadcast traffic, the first device  110  may determine whether a sixth configuration (for example, PDSCH-Config-Broadcast configuration) is configured for the first device  110 . If the sixth configuration is configured for the first device  110 , the first device  110  may determine the TDRA list from the sixth configuration. 
     In some embodiments, if the sixth configuration is not configured for the first device  110 , the first device  120  may determine whether a second configuration is configured for the first device  110 . If the second configuration is configured for the first device  110 , the first device  110  may determine the TDRA list from the second configuration. If the second configuration is not configured for the first device  110 , the first device  110  may determine the TDRA list from a fourth configuration (for example, a set of default A, B and C tables) based on a SS/PBCH block and CORESET multiplexing pattern. 
     Upon determination of the TDRA list, at block  430 , the first device  110  applies, based on the TDRA list, the TDRA field for reception of the traffic from the second device  120 . 
     With the method  400 , a terminal device in a connected state receiving multicast/unicast and broadcast traffic and a terminal device receiving only broadcast traffic may be enabled to interpret a common TDRA list to be used. Accordingly, a significant complexity reduction to a terminal device may be provided. 
     Correspondingly, embodiments of the present disclosure also provide a method of communication implemented at a second device.  FIG.  5    illustrates a flowchart of a method  500  of communication implemented at a second device according to example embodiments of the present disclosure. The method  500  can be implemented at the second device  120  shown in  FIG.  1   . For the purpose of discussion, the method  500  will be described with reference to  FIG.  1   . It is to be understood that method  500  may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. 
     As shown in  FIG.  5   , at block  510 , the second device  120  transmits, to the first device  110 , DCI comprising a TDRA field. 
     At block  520 , the second device  120  determines, based on at least one of an identifier for scrambling the DCI, a RRC of the first device  110  or a type of traffic configured for the first device  110 , a TDRA list from a set of configurations for TDRA. 
     In some embodiments, the RRC state of the first device  110  may be one of a connected state, idle state and inactive sate. In some embodiments, the type of traffic is at least one of broadcast traffic, multicast traffic or unicast traffic. 
     In some embodiments, if the first device  110  is in a connected state and the type of traffic is at least broadcast and multicast traffic, the second device  120  may determine whether a first configuration (for example, PDSCH-Config-Multicast configuration) is configured for the first device  110 . If the first configuration is configured for the first device  110 , the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the first device  110  may determine the TDRA list from the first configuration. 
     In some embodiments, if the first configuration is not configured for the first device  110 , the second device  120  may determine whether a second configuration (for example, PDSCH-Config-Common configuration) is not configured for the first device  110 . If the second configuration is configured for the first device  110 , the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the second device  120  may determine the TDRA list from the second configuration. 
     In some embodiments, if the second configuration is not configured for the first device  110 , the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the second device  120  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. If the predetermined identifier is associated with multicast traffic, the second device  120  may determine the TDRA list from a third configuration (for example, default A table). If the predetermined identifier is associated with broadcast traffic, the second device  120  may determine the TDRA list from a fourth configuration (for example, a set of default A, B and C tables) based on a SS/PBCH block and CORESET multiplexing pattern. 
     In some embodiments, the second device  120  may transmit, to the first device  110 , an indication indicating whether a second configuration (for example, PDSCH-Config-Common configuration) or a fifth configuration (for example, PDSCH-Config configuration) is used for the determination of the TDRA list. 
     In these embodiments, if the first configuration is not configured for the first device  110 , the second device  120  may determine, based on the indication, whether the second configuration or the fourth configuration is used. If the second configuration is used, the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the second device  120  may determine the TDRA list from the second configuration. In some embodiments, if the fifth configuration is used, the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the second device  120  may determine the TDRA list from the fifth configuration. 
     In some embodiments, if the first device  110  is in a connected state and the type of traffic is at least broadcast and multicast traffic, the second device  120  may determine whether a first configuration (for example, PDSCH-Config-Multicast configuration) is configured for the first device  110 . If the first configuration is configured for the first device  110 , the second device  120  may determine whether the identifier is a predetermined identifier. If the identifier is the predetermined identifier, the second device  120  may determine whether the predetermined identifier is associated with multicast traffic or broadcast traffic. If the predetermined identifier is associated with multicast traffic, the second device  120  may determine the TDRA list from the first configuration. If the predetermined identifier is associated with broadcast traffic, the second device  120  may determine whether a sixth configuration (for example, PDSCH-Config-Broadcast configuration) is configured for the first device  110 . If the sixth configuration is configured for the first device  110 , the second device  120  may determine the TDRA list from the sixth configuration. 
     In some embodiments, if the sixth configuration is not configured for the first device  110 , the second device  120  may determine whether a second configuration is configured for the first device  110 . If the second configuration is configured for the first device  110 , the second device  120  may determine the TDRA list from the second configuration. If the second configuration is not configured for the first device  110 , the second device  120  may determine the TDRA list from a fourth configuration (for example, a set of default A, B and C tables) based on a SS/PBCH block and CORESET multiplexing pattern. 
     Upon determination of the TDRA list, at block  530 , the second device  120  applies, based on the TDRA list, the TDRA field for transmission of the traffic to the first device  110 . 
     With the method  500 , a terminal device in a connected state receiving multicast/unicast and broadcast traffic and a terminal device receiving only broadcast traffic may be enabled to interpret a common TDRA list to be used. Accordingly, a significant flexibility to schedule MBS may be provided. 
     The operations in the methods of  FIGS.  4  and  5    correspond to that in the process described in  FIG.  2   , and thus other details are omitted here. 
     In some embodiments, an apparatus (for example, the first device  110 ) capable of performing the method  400  may comprise means for performing the respective steps of the method  400 . The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. 
     In some embodiments, the apparatus may comprise: means for receiving, at a first device and from a second device, downlink control information comprising a time domain resource allocation field; means for determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and means for applying, based on the time domain resource allocation list, the time domain resource allocation field for reception of the traffic from the second device. 
     In some embodiments, the radio resource control state of the first device is one of a connected state, idle state and inactive sate, and the type of traffic is at least one of broadcast traffic, multicast traffic or unicast traffic. 
     In some embodiments, the means for determining the time domain resource allocation list comprises means for: in accordance with a determination that the first device is in a connected state and the type of traffic is at least broadcast and multicast traffic, determining whether a first configuration is configured for the first device; in accordance with a determination that the first configuration is configured for the first device, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the first configuration. 
     In some embodiments, the means for determining the time domain resource allocation list further comprises means for: in accordance with a determination that the first configuration is not configured for the first device, determining whether a second configuration is not configured for the first device; in accordance with a determination that the second configuration is configured for the first device, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the second configuration. 
     In some embodiments, the means for determining the time domain resource allocation list further comprises means for: in accordance with a determination that the second configuration is not configured for the first device, determining whether the identifier is a predetermined identifier; in accordance with a determination that the identifier is the predetermined identifier, determining whether the predetermined identifier is associated with multicast traffic or broadcast traffic; in accordance with a determination that the predetermined identifier is associated with multicast traffic, determining the time domain resource allocation list from a third configuration; and in accordance with a determination that the predetermined identifier is associated with broadcast traffic, determining the time domain resource allocation list from a fourth configuration based on a synchronization signal/physical broadcast channel block and control resource set multiplexing pattern. 
     In some embodiments, the apparatus may further comprise means for receiving, from the second device, an indication indicating whether a second configuration or a fifth configuration is used for the determination of the time domain resource allocation list. 
     In these embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the first configuration is not configured for the first device, determining, based on the indication, whether the second configuration or the fourth configuration is used; in accordance with a determination that the second configuration is used, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the second configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the fifth configuration is used, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the fifth configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may comprise means for: in accordance with a determination that the first device is in a connected state and the type of traffic is at least broadcast and multicast traffic, determining whether a first configuration is configured for the first device; in accordance with a determination that the first configuration is configured for the first device, determining whether the identifier is a predetermined identifier; in accordance with a determination that the identifier is the predetermined identifier, determining whether the predetermined identifier is associated with multicast traffic or broadcast traffic; in accordance with a determination that the predetermined identifier is associated with multicast traffic, determining the time domain resource allocation list from the first configuration; in accordance with a determination that the predetermined identifier is associated with broadcast traffic, determining whether a sixth configuration is configured for the first device; and in accordance with a determination that the sixth configuration is configured for the first device, determining the time domain resource allocation list from the sixth configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the sixth configuration is not configured for the first device, determining whether a second configuration is configured for the first device; in accordance with a determination that the second configuration is configured for the first device, determining the time domain resource allocation list from the second configuration; and in accordance with a determination that the second configuration is not configured for the first device, determining the time domain resource allocation list from a fourth configuration based on a synchronization signal/physical broadcast channel block and control resource set multiplexing pattern. 
     In some embodiments, the first device is a terminal device, and the second device is a network device. In some embodiments, the first configuration is a PDSCH-Config-Multicast configuration, the second configuration is a PDSCH-ConfigCommon configuration, the third configuration is a default A table, the fourth configuration is a set of default A, B and C tables, the fifth configuration is a PDSCH-Config configuration, and the sixth configuration is a PDSCH-Config-Broadcast configuration. 
     In some embodiments, an apparatus (for example, the second device  120 ) capable of performing the method  500  may comprise means for performing the respective steps of the method  500 . The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. 
     In some embodiments, the apparatus may comprise: means for transmitting, at a second device and to a first device, downlink control information comprising a time domain resource allocation field; means for determining, based on at least one of an identifier for scrambling the downlink control information, a radio resource control state of the first device or a type of traffic configured for the first device, a time domain resource allocation list from a set of configurations for time domain resource allocation; and means for applying, based on the time domain resource allocation list, the time domain resource allocation field for transmission of the traffic to the first device. 
     In some embodiments, the radio resource control state of the first device is one of a connected state, idle state and inactive sate, and the type of traffic is at least one of broadcast traffic, multicast traffic or unicast traffic. 
     In some embodiments, the means for determining the time domain resource allocation list comprises means for: in accordance with a determination that the first device is in a connected state and the type of traffic is at least broadcast and multicast traffic, determining whether a first configuration is configured for the first device; in accordance with a determination that the first configuration is configured for the first device, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the first configuration. 
     In some embodiments, the means for determining the time domain resource allocation list further comprises means for: in accordance with a determination that the first configuration is not configured for the first device, determining whether a second configuration is not configured for the first device; in accordance with a determination that the second configuration is configured for the first device, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the second configuration. 
     In some embodiments, the means for determining the time domain resource allocation list further comprises means for: in accordance with a determination that the second configuration is not configured for the first device, determining whether the identifier is a predetermined identifier; in accordance with a determination that the identifier is the predetermined identifier, determining whether the predetermined identifier is associated with multicast traffic or broadcast traffic; in accordance with a determination that the predetermined identifier is associated with multicast traffic, determining the time domain resource allocation list from a third configuration; and in accordance with a determination that the predetermined identifier is associated with broadcast traffic, determining the time domain resource allocation list from a fourth configuration based on a synchronization signal/physical broadcast channel block and control resource set multiplexing pattern. 
     In some embodiments, the apparatus may further comprise means for receiving, from the second device, an indication indicating whether a second configuration or a fifth configuration is used for the determination of the time domain resource allocation list. 
     In these embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the first configuration is not configured for the first device, determining, based on the indication, whether the second configuration or the fourth configuration is used; in accordance with a determination that the second configuration is used, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the second configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the fifth configuration is used, determining whether the identifier is a predetermined identifier; and in accordance with a determination that the identifier is the predetermined identifier, determining the time domain resource allocation list from the fifth configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may comprise means for: in accordance with a determination that the first device is in a connected state and the type of traffic is at least broadcast and multicast traffic, determining whether a first configuration is configured for the first device; in accordance with a determination that the first configuration is configured for the first device, determining whether the identifier is a predetermined identifier; in accordance with a determination that the identifier is the predetermined identifier, determining whether the predetermined identifier is associated with multicast traffic or broadcast traffic; in accordance with a determination that the predetermined identifier is associated with multicast traffic, determining the time domain resource allocation list from the first configuration; in accordance with a determination that the predetermined identifier is associated with broadcast traffic, determining whether a sixth configuration is configured for the first device; and in accordance with a determination that the sixth configuration is configured for the first device, determining the time domain resource allocation list from the sixth configuration. 
     In some embodiments, the means for determining the time domain resource allocation list may further comprise means for: in accordance with a determination that the sixth configuration is not configured for the first device, determining whether a second configuration is configured for the first device; in accordance with a determination that the second configuration is configured for the first device, determining the time domain resource allocation list from the second configuration; and in accordance with a determination that the second configuration is not configured for the first device, determining the time domain resource allocation list from a fourth configuration based on a synchronization signal/physical broadcast channel block and control resource set multiplexing pattern. 
     In some embodiments, the first device is a terminal device, and the second device is a network device. In some embodiments, the first configuration is a PDSCH-Config-Multicast configuration, the second configuration is a PDSCH-ConfigCommon configuration, the third configuration is a default A table, the fourth configuration is a set of default A, B and C tables, the fifth configuration is a PDSCH-Config configuration, and the sixth configuration is a PDSCH-Config-Broadcast configuration. 
       FIG.  6    is a simplified block diagram of a device  600  that is suitable for implementing embodiments of the present disclosure. The device  600  may be provided to implement the first device or the second device, for example the first device  110  or the second device  120  as shown in  FIG.  1   . As shown, the device  600  includes one or more processors  610 , one or more memories  620  coupled to the processor  610 , and one or more communication modules  640  (such as, transmitters and/or receivers) coupled to the processor  610 . 
     The communication module  640  is for bidirectional communications. The communication module  640  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  610  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  600  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  620  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)  624 , 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)  622  and other volatile memories that will not last in the power-down duration. 
     A computer program  630  includes computer executable instructions that are executed by the associated processor  610 . The program  630  may be stored in the ROM  624 . The processor  610  may perform any suitable action and processing by loading the program  630  into the RAM  622 . 
     The embodiments of the present disclosure may be implemented by means of the program  630  so that the device  600  may perform any process of the disclosure as discussed with reference to  FIGS.  1  to  5   . 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  630  may be tangibly contained in a computer readable medium which may be included in the device  600  (such as in the memory  620 ) or other storage devices that are accessible by the device  600 . The device  600  may load the program  630  from the computer readable medium to the RAM  622  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.  7    shows an example of the computer readable medium  700  in form of CD or DVD. The computer readable medium has the program  630  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 methods  400 - 500  as described above with reference to  FIGS.  4 - 5   . 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.