Settings of Communication Device

Abstract

Summary A method and apparatus for multicast services. In one method, a resource message is received on a control channel indicating a first search space type and aiding information information for the first search space type. Based on the aiding information information, it is determined that a second search space type is applied to monitoring the multicast search space. The monitoring of the multicast search space is provided according to the second search space type.

Description

Technical Field

[0001] The present disclosure relates to a method, an apparatus, and a computer program product for configuring a communication device for multicast in a communication system.

Background Art

[0002] Data can be communicated between communication devices such as users or terminal devices, base stations / access points, and / or other nodes. Communication is provided, for example, by a communication network and one or more compatible communication devices. The communication device on the network side provides an access point to the system and is equipped with appropriate signal receiving and transmitting devices to enable communication, for example, to allow other devices to access the communication system. Communication can consist of, for example, the communication of data for transmitting communications such as voice, video, email (E-mail), text messages, multimedia, and / or content data. Non-limiting examples of the services provided include two-way or multi-way calls, data communication, multimedia services, access to data network systems such as the Internet. Multicast / broadcast to communication devices is also possible.

[0003] In a mobile communication system or a wireless communication system, at least a part of the data communication between at least two devices is performed via a wireless link or wireless links. Examples of wireless systems include public land mobile networks (PLMNs), satellite-based communication systems, and various wireless local networks, such as wireless local area networks (WLAN). A wider communication system is realized by appropriate communication devices or terminals. Such devices may be called user devices (UE).

[0004] A communication device includes appropriate signal receiving and transmitting devices for enabling communication, such as enabling access to a communication network or direct communication with other users. The user's communication device can receive signals from a station of a radio access network, such as a base station, and transmit and / or receive communications accordingly.

[0005] Communication systems and related devices typically operate according to a predetermined standard or specification that defines what various entities associated with the system are permitted to do and how they should be implemented. The communication protocols and parameters used for connections are also generally defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems include the Long-Term Evolution (LTE) of Universal Mobile Telecommunications System (UMTS) radio access technology and the so-called fifth-generation (5G) or New Radio (NR) networks. 5G is standardized by the Third Generation Partnership Project (3GPP (registered trademark)).

[0006] Multicast Broadcast Service (MBS) is a point-to-multipoint communication method. Different from unicast services, it can transmit data from one source to multiple destinations / devices simultaneously. Broadcast refers to the function of delivering content to all users. Multicast refers to delivering the content of a service among a specific group of devices or users subscribed to that service. SUMMARY OF THE INVENTION

[0007] According to one aspect, there is provided a method in a communication device, including receiving, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type; determining, based on the assistance information, that a second search space type is applicable to monitoring of a multicast search space; and monitoring the multicast search space according to the second search space type.

[0008] According to one aspect, there is provided a method of configuring a communication device, the method including the step of transmitting, to the communication device, a control message for setting radio resource reception, the message indicating a first search space type and assistance information for the first search space type, enabling the communication device to determine that a second search space type is applied for monitoring a multicast search space, and multicasting data on the radio resource to the communication device.

[0009] According to yet another aspect, there is provided a method in a communication device, the method including the steps of receiving a control channel multicast-broadcast service configuration message, determining that the message indicates a monitoring priority rule for a specific search space type, and selecting a different type of applied monitoring priority based on determining whether at least one of downlink control information formats defined for a group common physical downlink control channel is configured.

[0010] According to an aspect, there is provided an apparatus for a communication device, the apparatus including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, using the at least one processor, cause the apparatus to at least receive, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type, determine, based on the assistance information, that a second search space type is applied for monitoring a multicast search space, and monitor the multicast search space according to the second search space type.

[0011] According to one aspect, an apparatus for a communication network is provided, the apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, using the at least one processor, cause the apparatus to at least: transmit, to a communication device, a control message for configuring wireless resource reception, the message indicating a first search space type and auxiliary information for the first search space type, and enabling the communication device to determine that a second search space type is applied to monitoring of a multicast search space; and multicast data to the communication device over the wireless resources.

[0012] According to yet another aspect, an apparatus for a communication device comprising at least one processor and at least one memory including computer program code is provided, the at least one memory and the computer program code being configured to cause the apparatus to at least: receive, by the at least one processor, a control channel multicast-broadcast service configuration message; determine that the message indicates a monitoring priority rule indicating a specific search space type; and select a different type of monitoring priority to be applied based on a determination as to whether at least one of a downlink control information format defined for a group common physical downlink control channel is configured.

[0013] According to a more specific aspect, the first search space type comprises a common search space type-3. The second search space type may be constituted by a common search space type for scheduling multicast / broadcast services.

[0014] The resource message may explicitly indicate the first search space type and implicitly indicate the second search space type.

[0015] The second search space type can be used to indicate the priority of monitoring.

[0016] The communication device can determine the second search space type based on the information of the resources associated with the set of common search spaces in the common frequency band and the search space set index.

[0017] The resource message can include a radio resource control message that includes information on the control resource set resources associated with the set of common search spaces.

[0018] In response to determining that the control resource set resources associated with the set of common search spaces are completely included within the common frequency band and that the downlink control information format associated with the set of common search spaces includes at least one of the downlink control information formats defined for the group common physical downlink control channel, the communication device can determine that the monitoring is based on the second search space type.

[0019] The downlink control information format may include a format defined for scheduling multicast and / or broadcast traffic. The downlink control information format is composed of format 1_0 and / or 1_1.

[0020] The communication device may determine whether a search space index reservation is set.

[0021] The resource message may be composed of a pdcch-config message or a pdcch-config-mbs message. The communication device that receives the pdcch-config-mbs message can determine that the message indicates a monitoring priority rule for a specific type of application, and select the type of the monitoring priority rule based on determining whether at least one of the downlink control information formats defined for the group common physical downlink control channel is set.

[0022] Means for implementing the operations and functions disclosed in this specification may also be provided. This means may be composed of appropriately configured hardware and software.

[0023] It is also possible to provide a computer software product that implements at least a part of the functions described in this specification. According to one aspect, the computer program includes instructions for executing at least one of the methods described in this specification.

Brief Description of the Drawings

[0024] Next, several aspects will be described in more detail by way of example only, with reference to the following examples and the accompanying drawings.

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Modes for Carrying Out the Invention

[0025] The following description exemplarily illustrates several possibilities for implementing the present invention. This specification may refer to "a", "one", or "some" embodiments or implementations at several places in the text, but this does not necessarily mean that each reference is made to the same embodiment or implementation, or that a particular feature applies only to a single embodiment or implementation. It is also possible to combine single features of different examples or embodiments to provide other embodiments.

[0026] A wireless communication system provides wireless communication to devices connected thereto. Usually, an access point such as a base station is provided to enable communication. Hereinafter, different scenarios will be described using the 3GPP 5G wireless architecture as an example of an access architecture. However, the embodiments are not necessarily limited to such an architecture. Examples of suitable system options include Universal Mobile Telecommunications System (UMTS) radio access networks (UTRAN or E-UTRAN), Long Term Evolution (LTE), LTE-A (LTE-Advanced), Wireless Local Area Network (WLAN or Wi-Fi (registered trademark)), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth (registered trademark) Personal Communication Service (PCS), ZigBee (registered trademark), Wideband Code Division Multiple Access (WCDMA (registered trademark)), systems using Ultra-Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANETs), Cellular IoT (Internet of Things) RAN, Internet Protocol Multimedia Subsystem (IMS), or combinations and further developments thereof.

[0027] FIG. 1 shows a wireless system 1 including a wireless access system or a radio access network (RAN) 2. The wireless access system may be composed of one or more access points, or base stations 12. The base station can provide one or more cells. The access point may be composed of any node capable of transmitting and receiving wireless signals (for example, 3GPP 5G base stations such as TRP, gNB, eNB, user devices, etc.). The communication system can provide a number of wireless access systems.

[0028] The communication device 10 can be arranged in the service area of the wireless access system 2. For simplicity, only some devices are shown, and in the following description, the operation will be described in relation to one of the devices. The device 10 can listen to the access point 12. The communication from the device 10 to the access point 12 is generally called an uplink (UL). The communication from the access point 12 to the device 10 is generally called a downlink (DL).

[0029] Note that the more extensive communication system is only shown as the cloud 2 and may be composed of many elements not shown for clarity. For example, the operation according to a 5G-based system may be composed of a terminal or user equipment (UE), a 5G radio access network (5GRAN) or a next-generation radio access network (NG-RAN), a 5G core network (5GC), one or more application functions (AF), and one or more data networks (DN). The 5G-RAN may be composed of one or more gNodeBs (gNBs), or one or more gNodeB distributed unit functions connected to one or more gNodeB centralized unit functions. Also, the 5GC may be composed of entities such as a network slice selection function (NSSF), a network exposure function, a network repository function (NRF), a policy control function (PCF), an integrated data management (UDM), an application function (AF), an authentication server function (AUSF), an access & mobility management function (AMF), a session management function (SMF), etc.

[0030] The communication device 10 may be any suitable device adapted for wireless communication. The wireless communication device may be provided by any device capable of transmitting and receiving wireless signals. Non-limiting examples include a mobile station (MS) (such as a mobile device known as a mobile phone or a "smartphone"), a computer equipped with a wireless interface card or other wireless interface equipment (such as a USB dongle), a personal data assistant (PDA) or a tablet equipped with a wireless communication function, a machine-type communication (MTC) device, an Internet of Things (IoT) type communication device, a cellular Internet of Things (CIoT) device, or any combination thereof. The device may be provided as part of another device. The device can receive signals via an air interface or a wireless interface through a suitable device for reception, and can transmit signals through a suitable device for transmitting wireless signals. The communication is performed via multiple paths. To enable MIMO type communication, the device can be equipped with a multi-antenna element.

[0031] FIG. 1 further shows the downlink signaling according to a particular embodiment by arrow 11. This signaling can include (11a) the upper layer configuration of the search space set and (11b) the assistance information for determining the monitoring priority of the configured search space set.

[0032] A communication device such as the access point 12 or the device 10 includes a data processing device including at least one processor and at least one memory. FIG. 2 shows an example of a data processing device 50 composed of processors 52, 53 and a memory or memories 51. FIG. 2 further shows the connections between the elements of the device and the interface for connecting the data processing device to other components of the device.

[0033] At least one memory can be composed of at least one ROM and / or at least one RAM. The communication device is equipped with software for tasks designed to be executed and other possible components for hardware-assisted execution, which includes access systems and control of access and communication to other communication devices, and implements the functions of the devices described herein in relation to the multicast / broadcast (MBS) service. At least one processor can be coupled to at least one memory. At least one processor can be configured to execute appropriate software code to implement one or more of the following aspects. The software code can be stored in at least one memory, for example, at least one ROM.

[0034] Hereinafter, using 5G terms, specific aspects, configurations, and signaling of multicast / broadcast-related operations will be described. The multicast / broadcast service (MBS) is a function of a mobile communication system. MBS is a point-to-multipoint communication method that can transmit data from one source to multiple destinations / devices simultaneously. Broadcast refers to the function of delivering content to all users. Multicast refers to delivering the content of a service among specific devices or groups of users subscribed to that service. Multicast and broadcast content may be transmitted over a geographical area called a zone. An MBS zone is a collection of one or more network access nodes (such as base stations) that can transmit the same content.

[0035] In 3GPP 5G / NR multicast standardization, currently, efforts are being made on the delivery mechanism of multicast / broadcast traffic to a large number of receiving devices (UEs). The purpose is to define a group scheduling mechanism that can schedule multicast / broadcast traffic using common data channel resources while maintaining maximum commonality with the already defined unicast scheduling and operation mechanisms. Using common data channel resources to schedule downlink data of multicast / broadcast services (MBS) can be problematic, especially for different search space (SS) types with different monitoring priorities. In the radio resource control (RRC) connected mode, the currently relevant SS types are type 3 common SS (type 3 CSS) and UE-specific SS (USS). Currently, type 3 CSS is always prioritized over USS type. Monitoring priority rules / options are needed where the priority of the SS set for multicast may be lower than that of type 3 CSS and the configurable priority (up / down / inside) compared to USS. In case of overbooking, monitoring may be prioritized. For example, if a UE is composed of more SS sets / PDCCH candidates than it can monitor, the UE needs to prioritize the search spaces so that it can only monitor the search spaces with high priority.

[0036] According to the current situation of 5G, the Type-3 Physical Downlink Control Channel (PDCCH) / Search Space (SS) set with the "type=common" configuration, which is configured using Radio Resource Control (RRC) after connection establishment, is used for the configuration of the Common Search Space (CSS) set, and the "type=UE-specific" configuration is used for the configuration of the UE-specific Search Space (USS) set. Since multicast is only applicable to UEs in the connected mode, only type-3 is applicable in that scenario. Therefore, the UE-specific Search Space (USS) and Type-3 CSS can only be configured after establishing an RRC connection. The UE and the gNB map the PDCCH (Physical Downlink Control Channel) candidates of each slot as follows based on the RRC configuration. (i) The CSS set is mapped before the USS set, (ii) The USS set is mapped in ascending order of the SS set index. If the number of PDCCH candidates / CCEs exceeds any of the UE processing limitations, (iii) No more SS sets are mapped to the slots after reaching the UE processing limitations. With these rules, the base station (BS) can number the SS sets of the connected UEs according to the desired priorities.

[0037] The currently defined mechanism cannot be reused for other types because the SS set for multicast can have a lower priority than the CSS and has a monitoring priority rule with a configurable priority within the USS. It is agreed that the monitoring priority of the SS set used for multicast traffic scheduling can be above, below, or configurable within the USS set. This CSS set is called the multicast search space (MSS), performs flexible prioritization between the CSS and the USS based on the SS index, and has the same characteristics as the CSS otherwise. That is, this type of CSS can be called type-x CSS. The monitoring priority of type-x CSS can be applied, for example, in the case of overbooking. That is, when the number of PDCCH candidates is more than the number of PDCCH candidates that the UE can monitor, the UE can prioritize the search space so that only the search space with a high priority is monitored, and when the UE cannot monitor, the search space with a low priority can be ignored.

[0038] Downlink control information (DCI) is transmitted on the PDCCH. Generally, DCI is used to indicate uplink or downlink resource allocation for one radio network temporary identifier (RNTI). As an extension of this, a control resource set (CORESET) generally means the time and frequency allocation of the PDCCH and is generalized to a set of resource blocks and symbols. Thus, DCI can convey various information. The useful content of DCI varies depending on the specific cases of system deployment and operation. The downlink control information (DCI) formats based on the currently defined C-RNTI (Cell-Radio Network Temporary Identity) formats 1_0 and 1_1 can be used by the gNB as a baseline to notify the UE of the group common physical downlink shared channel (PDSCH) resources on which multicast / broadcast downlink data is scheduled. Currently, since these formats are only defined for unicast traffic, the access node (gNB in 5G) can use any of these DCI formats to notify the UE of the scheduled downlink information to be scheduled on the PDSCH using the UE-specific PDCCH. Therefore, DCI formats 1_0 and 1_1 can be used for scheduling the PDSCH resources of multicast traffic with CRC scrambled using the group common / G-RNTI. As will be described in detail below, DCI format 1_1 can be configured with type-x CSS for UEs receiving multicast traffic.

[0039] The SS set can be configured using the pdcch-config message. In the case of MBS, the gNB can optionally configure the UE using the RRC configuration message pdcch-config-mbs that includes the SS set. This is an optional configuration, and the gNB can reuse the existing pdcch-config to configure the SS set parameters related to MBS according to the implementation of the gNB.

[0040] Multicast / broadcast traffic can be scheduled within the common frequency region (CFR) within the UE active bandwidth part (BWP). The configuration of the common frequency region (CFR) (including the starting physical resource block (PRB) and size) is notified to the UE via RRC. Therefore, all UEs within the zone can recognize the common frequency region (CFR) where multicast traffic is scheduled. The CSS for multicast can have a different priority from the CSS for unicast. However, it is unknown how the UE knows whether the configured CSS is for unicast or multicast.

[0041] A specific monitoring priority different from the currently defined monitoring priority (referred to as "type-x" in this specification) is required. However, there is no agreement on the explicit definition of type-x CSS and the mechanism for signaling its type. This means that, as part of the RRC configuration, it is not defined how type-x can be explicitly signaled to a receiving device such as a UE. Although "type-x" is part of type-3 CSS from the perspective of the RRC configuration, "type-x" requires a monitoring priority different from that of "type-3". However, the UE cannot notify the search space, configuration type by explicit signaling for SS type-x. That is, the UE cannot recognize whether the monitoring priority of the currently defined CSS (type-3) should be applied or the monitoring priority of type-x CSS that depends on the SS set index should be applied.

[0042] According to a possible approach to address this issue, the network can implicitly notify the UE that the configured search space is the CSS for MBS (i.e., type-x CSS) rather than other types. This enables the UE to perform prioritization of blind decoding attempts without the need to explicitly define a new CSS type in the RRC signaling. Depending on the possibility, information on different criteria is combined to implicitly indicate that it is type-x CSS. As a possibility to avoid signaling the SS configuration that explicitly includes the configured CSS type and index, it is separately notified to the receiving device (UE) that another type of configuration (type-3) is signaled and the signaled index uses the monitoring priority of another type (type-x in this example) instead.

[0043] The flowchart of FIG. 3 shows a general example of processing possible in a communication device. In this method, at 100, the communication device receives, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type. Next, at 102, the device determines, based on the assistance information, to apply a second search space type instead of the first type to monitoring of the multicast search space. Then, at 104, the device applies the second search space type for monitoring of the multicast search space.

[0044] FIG. 4 shows a more detailed example where the first two steps 100 and 102 are as described above. The device is configured to monitor, at 106, a search space in which multicast downlink control information can be scheduled according to a monitoring priority indicated by the second search space type. The device monitors the search space at 108 according to the monitoring priority of the second search space type.

[0045] FIG. 5 shows possible operations on the network side at a node that transmits signaling for configuring a communication device. The method includes, at 110, transmitting, on a control channel to the communication device, a resource message indicating a first search space type and assistance information for a common search space, the assistance information including information that enables the communication device to determine, based on the assistance information, that the second search space type is configured for monitoring of the multicast search space. Data is multicast at 112 by the node to the device on a resource, and reception by the device is based on a monitoring priority configuration of the multicast search space according to the second search space type and the assistance information.

[0046] Figure 6 shows yet another possible operation on the receiving device side. The device 120 can receive a multicast-broadcast service configuration message. It is determined at 122 that the message indicates a monitoring priority rule for a certain search space type. Different types of applied monitoring priorities can be selected at 126 based on a determination at 124 as to whether at least one of the downlink control information formats defined for the group common physical downlink control channel is set.

[0047] The first search space type may be composed of the common search space type-3. The second search space type may be composed of the common search space type for the multicast / broadcast service (type-x).

[0048] A more detailed example will be described below. A communication device called UE can configure a search space set using the existing RRC specification even when there is no explicit definition of a new search space type for type-x CSS. The UE is configured to interpret whether to apply the monitoring priority defined for CSS or the monitoring priority of type-x CSS that depends on the index / ID of the SS set. To provide differentiated priorities, the existing signaling of "SS type = common" can be used, and there is no need to newly add an explicit definition of the SS type so that the UE can apply differentiated priorities.

[0049] In a detailed example, without explicitly defining a new search space type, by reusing the currently defined search space RRC configuration, it is indicated to the UE whether to apply type-3 PDCCH-based monitoring priority or type-x PDCCH-based monitoring priority. In the example, the cost of explicit signaling is avoided or at least reduced. If the UE has set both G-RNTI and C-RNTI-based DCI, it is necessary to provide two separate RRC configurations. Explicitly signaling that type-x should be applied would incur additional overhead, so this can be avoided by reusing the current signaling as much as possible and enabling the UE to determine the method of applying differentiated priorities.

[0050] The user device can apply differentiated monitoring prioritization for a set of search spaces in which downlink control information for multicast / broadcast traffic is scheduled, using assistance information from the network. Various mechanisms for determining the monitoring prioritization for the search space can be configured for the UE. According to one example, the UE can assume that a type-3 CSS configured using the pdcch-config message is a type-x CSS / MSS when the following two conditions are met. This is the case when the CORESET resources associated with the SS set are fully included in the (MBS)CFR and the DCI format associated with the CSS set includes the format defined for group common PDCCH. Examples of these are the already mentioned DCI formats 1_0 and / or 1_1. Thereafter, the UE applies a new monitoring priority based on the SS index of the SS set while performing flexible prioritization between the CSS and the USS regardless of the type of the configured SS set. Otherwise, the UE applies the conventional priority rules. That is, when DCI formats 1_0 and / or 1_1 are not configured, the UE can assume that it is a type 3 CSS with a higher monitoring priority than the USS regardless of the SS index / ID.

[0051] The UE can be configured to interpret the CSS type based on the configured DCI type. Detailed examples implicitly indicating the type are shown in FIGS. 7 to 9. The gNB can always configure the SS type as common, but the UE can distinguish between type-x CSS and type-3 CSS based on the analysis of the assistance information. The assistance information consists of one or more of the location of the CORESET resources related to the MBS CFR, the RRC configuration type used (whether the message is pdcch-config or pdcch-config-mbs), or an explicit SS index reservation.

[0052] When priority determination can be based on the pdcch-config / pdcch-config-mbs message, an overview of an exemplary method is shown in the flowchart of FIG. 7. This flowchart shows the operation from the perspective of the UE in terms of the logic applied after receiving a resource message for determining the monitoring priority of a given SS set. Since the gNB can use either or both of the pdcch-config and pdcch-config-mbs messages to configure the search space set and the associated CORESET, both options are considered.

[0053] It should be understood that arrangements and operations are also possible where only one of the branches is executed. That is, the selection step 204 is not necessary for all applications, and only one of the messages may be used in the configuration. The receiving device / its program code may be configured to execute only one of the branches.

[0054] The configuration starts at 200, and the UE is configured using the CFR information at 202. Thereafter, the UE can determine at 204 whether the CORESET message was the pdcch-config message or the pdcch-config-mbs message. If the gNB uses pdcch-config for the configuration of type-x CSS, the UE needs to determine at 206 whether a group common PDCCH format (based on DCI format 1_0 / 1_1) is configured within the SS set. In the case of "yes", at 208, it is determined whether the associated CORESET resource is completely included within the MBS CFR. The CORESET resource is included within the MBS CFR to ensure that all UEs monitor the common resources on which the DCI can be scheduled.

[0055] If the answer is NO at 206 or 208, the UE knows to apply the type 3 CSS-based monitoring priority at 210, and the determination process stops.

[0056] If both tests are positive, the monitoring priority based on type-x CSS is applied with a value of 212, and the decision process can stop.

[0057] In 04, if it is determined that the gNB uses pdcch-config-mbs to configure type-x CSS, the UE can determine in 214 whether a flag for applying type-x monitoring priority is configured. If this flag is set and pdcch-config-mbs mainly targets MBS-related settings, the UE can determine in 216 that the type-x CSS monitoring priority rule is applied after checking whether the group-common PDCCH format (based on DCI format 1_0 / 1_1) is set within the SS set.

[0058] If the answer is "no" in 216 or 218, the UE knows to apply the type 3 CSS-based monitoring priority in 210, and the decision process stops.

[0059] If both tests are affirmative, the type-x CSS-based monitoring priority is applied in 212, and the decision process stops.

[0060] Figure 8 shows a flowchart of operations based on search space (SS) index reservation. The operations based on SS index reservation utilize the feature that the gNB can set / reserve the SS index value of the CFR. These can be set together with the MBS CFR parameters using upper layer / RRC signals, and the UE can handle them as Type-x CSS / MSS. Depending on the index reserved for type-x CSS, the gNB can apply monitoring prioritization for MSS and CSS. The UE can know whether a higher-priority search space type (type-3) is set based on the SS index, or whether a search space type with a different monitoring priority from type-3, i.e., type-x, is set.

[0061] If the UE determines at 304 that the configuration for reserving a specific SS index for type-x CSS is configured at 302, and further determines at 306 that a group common PDCCH is configured in the reserved SS set and the CORESET resource is fully included within the CFR, and determines at 308 that the DCI format is configured, then the UE can apply the CSS type-x based monitoring priority at 310. If the test is negative at any of steps 302, 304, 306, or 308, the type 3 CSS based priority is applied at 312.

[0062] Therefore, the gNB can set the SS set using the pdcch-config-mbs message. Since it can be assumed that the CORESET resource is always limited within the MBS CFR that can be set individually using RRC, the UE needs to apply the Type-x CSS / MSS based monitoring priority regardless of the configured DCI format. The priority of Type-x is applied only when the DCI format used for multicast scheduling is being used.

[0063] As an option, the gNB can send a new flag indicating whether it needs to consider an SS configured with type = common as a type 3 or type-x CSS within pdcch-config-mbs or other higher layer configuration signaling related to multicast / broadcast traffic.

[0064] In another example of priority determination based on SS index reservation, the checks in steps 304, 306, and 308 are not considered at all as an option, and only the reservation test based on the SS index in 302 is applied. Then, reserving the SS index depends on the implementation of the gNB only if the gNB is actually planning to construct the actual DCI containing information related to the MBS DCI format and group common PDCCH, or if the gNB requires the UE to apply a differentiated monitoring priority for type-x CSS.

[0065] Figure 9 shows a flowchart of a hybrid method that combines various options for configuring the UE. More specifically, priority determination based on the combined use of SS index reservation (shown in Figure 8) and the pdcch-config / pdcch-config-mbs method (shown in Figure 7) may be provided. The receiving device is configured to follow each branch according to the selected content.

[0066] Figure 10 shows an example of possible relationships between UE active BWPs, MBS CFRs, and common SS sets with different priority rules. In a possible configuration of the UE active BWP frequency resources, the MBS CFR resources included within the active BWP, and the PDCCH resources for the active BWP, When the pre-defined conditions as shown in FIGS. 6-8 are met, the UE can determine that SS ID #1 is a type-x CSS. This is because the CORESET resource is completely included within the MBS CFR. However, SS ID #2 cannot be a type-x CSS because the CORESET resource is not completely included within the MBS CFR.

[0067] In the above, specific non-limiting examples of using radio resource control (RRC) messages / signaling to configure the UE for search space (SS) monitoring were described. When the SS is composed of too many PDCCH candidates ("overbooking"), the UE applies PDCCH monitoring within the configured search space based on the monitoring priority of the applicable search space (the applicable priority is defined by the search type). In general operation, the common search space (CSS) is prioritized over the UE-specific search space (USS), and within the USS, prioritization is performed based on the SS index. The multicast search space (MSS) / type-x can be used to provide a differentiated priority between the CSS and the USS based on the SS index. The gNB can transmit multicast data to the configured UE. Whether the UE can receive multicast data depends on the search space priority and whether the UE can monitor the search space of the DCI message that includes the group-common PDSCH resource where the multicast data is scheduled.

[0068] Although exemplary embodiments have been described above, it should be noted that there are some variations and modifications that can be made to the disclosed solutions without departing from the scope of the present invention. Different features from different embodiments may be combined.

[0069] Accordingly, embodiments may vary within the scope of the appended claims. In general, some embodiments may be implemented in hardware or special purpose circuitry, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software executable by a controller, microprocessor, or other computing device, but the embodiments are not limited thereto. Various embodiments may be illustrated and described using block diagrams, flowcharts, or some other pictorial representation, but these blocks, devices, systems, techniques, or methods described herein are, by way of non-limiting example, hardware, software, firmware, special purpose circuitry or logic, general purpose hardware or controllers, or other computing devices, or some combination thereof.

[0070] Embodiments can be implemented by computer software stored in a memory and executable by at least one data processor of a related entity, or by hardware, or by a combination of software and hardware. Further in this regard, note that any of the above procedures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software can be stored in a physical medium such as a memory chip, a memory block implemented within a processor, a magnetic medium such as a hard disk or floppy disk, or an optical medium such as a DVD or a CD which is a data variant thereof.

[0071] The memory can be of any type suitable for the local technical environment and can be implemented using any appropriate data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processor can be of any type suitable for the local technical environment, and by way of non-limiting example, can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a gate-level circuit, and a processor based on a multi-core processor architecture. Alternatively or additionally, some embodiments can be implemented using circuits. The circuits may be configured to perform one or more of the functions and / or method steps described above. The circuits may be provided in a network entity and / or a communication device and / or a server and / or a device.

[0072] As used in this application, the term "circuit" may refer to one or more or all of the following. (a) A hardware-only circuit implementation (such as an implementation with only analog and / or digital circuits), (b) A combination of a hardware circuit and software (such as the following), (i) A combination of analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor with software (including a digital signal processor), software, and memory that cooperate to cause a communication device and / or a device and / or a server and / or a network entity to perform the various functions described above, and (c) A hardware circuit and / or a processor, such as a microprocessor or a part of a microprocessor, which requires software (e.g., firmware) for operation, but the software may not be present when it is not required for operation. This definition of a circuit applies to all uses of this term in this application, including any claims. As a further example, when used in this application, the term circuit also encompasses a hardware circuit or a processor (or processors) or a part of a hardware circuit or a processor, and the software and / or firmware implementation associated therewith. Also, the term circuit encompasses, for example, integrated devices.

[0073] Although embodiments have been described in relation to a particular architecture, it should be noted that the same principles can be applied to other systems. Thus, while specific exemplary architectures for wireless networks, technical standards, and protocols have been referred to and specific embodiments have been described above by way of example, the features described herein can be applied to any suitable form other than the systems, architectures, and devices illustrated and described in detail in the above examples. It should also be noted that different combinations of different embodiments are possible. Also, although exemplary embodiments have been described above, it should be noted herein that there are some variations and modifications that can be made to the disclosed solutions without departing from the spirit and scope of the present invention.

Claims

1. A method, comprising: a communication device receiving, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type; the communication device determining, based on the assistance information, that a second search space type is applicable to monitoring of a multicast search space; the communication device monitoring the multicast search space according to the second search space type.

2. A method, comprising: an access node transmitting, on a control channel, to a communication device a resource message for setting wireless resource reception, the resource message indicating a first search space type and assistance information for the first search space type so that the communication device can determine that a second search space type is applicable to monitoring of a multicast search space; the access node multicasting data to the communication device on a wireless resource.

3. An apparatus for a communication device, comprising at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to perform at least: receiving, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type; determining, based on the assistance information, that a second search space type is applicable to monitoring of a multicast search space; monitoring the multicast search space according to the second search space type.

4. The first search space type comprises a common search space type-3; the second search space type comprises a common search space type for scheduling a multicast / broadcast service, The apparatus according to claim 3.

5. The resource message explicitly indicates the first search space type and implicitly indicates the second search space type, The apparatus according to claim 3.

6. The second search space type indicates a monitoring priority, The apparatus according to claim 3.

7. When executed by the at least one processor, the instructions cause the processor to Determining the second search space type based on information of resources related to a common search space set within a common frequency range and a search space set index The apparatus according to claim 3, which causes the above to be executed **Claim 8** The apparatus according to claim 3, wherein the resource message includes a radio resource control message including information of a control resource set resource associated with a common search space set **Claim 9** When executed by the at least one processor, the instructions cause the processor to Determine that the monitoring is performed based on the second search space type in response to a determination that resources of a control resource set associated with a common search space set are completely included within a common frequency range and the downlink control information format associated with the common search space set includes at least one of the downlink control information formats defined for a group common physical downlink control channel The apparatus according to claim 3, which causes the above to be executed **Claim 10** The apparatus according to claim 9, wherein the downlink control information format includes a format defined for scheduling multicast and / or broadcast traffic **Claim 11** The apparatus according to claim 10, wherein the downlink control information format includes format 1_0 and / or 1_1 **Claim 12** The apparatus according to claim 9, wherein when executed by the at least one processor, the instructions cause the processor to execute a step of determining whether a search space index reservation is set **Claim 13** When executed by the at least one processor, the instructions cause the processor to Determine a step of indicating a monitoring priority rule indicating the application of a specific type; and Select a type of the monitoring priority rule based on a determination of whether at least one of the downlink control information formats defined for a group common physical downlink control channel is configured; and The apparatus according to any one of claims 3 to 12, which causes the above to be executed **Claim 14** An apparatus for an access node comprising at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to perform at least transmitting, on a control channel, a resource message that configures a first search space type to a communication device, the resource message indicating the first search space type and assistance information for the first search space type to enable the communication device to determine that a second search space type is applicable for monitoring a multicast search space; multicasting data to the communication device over wireless resources; An apparatus for performing the above.

15. The first search space type includes a common search space type - 3; The second search space type includes a common search space type for scheduling multicast / broadcast services; The apparatus according to claim 14.

16. The resource message explicitly indicates the first search space type; implicitly indicates the second search space type; The apparatus according to claim 14.

17. The second search space type indicates a monitoring priority; the apparatus according to claim 14.

18. The resource message includes a radio resource control message including information on a control resource set resource associated with a common search space set; the apparatus according to any one of claims 14 to 17.

19. When executed by an apparatus for a communication device, the apparatus performs at least receiving, on a control channel, a resource message indicating a first search space type and assistance information for the first search space type; determining, based on the assistance information, that a second search space type is applicable for monitoring a multicast search space; monitoring the multicast search space according to the second search space type; A computer-readable medium including program instructions for performing the above.

20. When executed by an apparatus for an access node, the apparatus performs at least A step of transmitting a resource message for setting wireless resource reception to a communication device on a control channel, wherein the resource message indicates a first search space type and assistance information for the first search space type for enabling the communication device to determine that a second search space type is applicable for monitoring a multicast search space, the step of transmitting; A step of multicasting data to the communication device on a wireless resource; A computer-readable medium including program instructions for causing the execution.

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