WO2022236650A1

WO2022236650A1 - User equipment, base station, and wireless communication method for mbs

Info

Publication number: WO2022236650A1
Application number: PCT/CN2021/092946
Authority: WO
Inventors: Ahmed MOHAMMED MIKAEIL; Jia SHENG
Original assignee: Tcl Communication(Ningbo)Co., Ltd.
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2022-11-17
Also published as: CN117280717A

Abstract

A user equipment (UE), a base station, and wireless communication methods for multicast/broadcast service (MBS) are provided. A wireless communication method for MBS performed by the UE includes receiving, from a base station, a configuration of frequency and time domain radio resources and a monitoring configuration, and monitoring, based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a system information SI channel, a paging channel, or a multicast control channel (MCCH) in a slot. This can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

Description

USER EQUIPMENT, BASE STATION, AND WIRELESS COMMUNICATION METHOD FOR MBS

BACKGROUND OF DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to the field of wireless communication systems, and more particularly, to a user equipment (UE) , a base station, and wireless communication methods for multicast/broadcast service (MBS) , which can provide a multicast control channel scheduling to support an efficient reception of an MBS transmitted over a point to multi-point (PTM) configuration.

2. Description of the Related Art

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These wireless communication systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as long term evolution (LTE) systems and fifth generation (5G) systems which may be referred to as new radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform-spread-OFDM (DFT-S-OFDM) . A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipments (UEs) . A wireless communication network may include a base station that can support communication for a UE. The UE may communicate with the base station via downlink (DL) and uplink (UL) . The DL refers to a communication link from the base station to the UE, and the UL refers to a communication link from the UE to the base station.

In a 3rd generation partnership project (3GPP) cellular network, broadcast and multicast services may be transported via a transport service called multimedia broadcast/multicast service (MBMS) . A broadcast multicast service center (BM-SC) server is responsible to disseminate a media content to a group of subscribers. When a UE moves out of a network coverage, the UE may be unable to use the MBMS because uplink and downlink connections to the BM-SC server are no longer available. MBMS is a point-to-multipoint (PTM) interface specification designed to provide efficient delivery of broadcast and multicast services within 3GPP cellular networks. Examples of MBMS interface specifications include those described in universal mobile telecommunication system (UMTS) and long term evolution (LTE) communication specifications. For broadcast transmission across multiple cells, the specifications define transmission over single-frequency network configurations. Intended applications include mobile TV, news, radio broadcasting, file delivery, emergency alerts, and others. When services are broadcasted by MBMS, all cells inside a multimedia broadcast/multicast service single frequency network (MBSFN) area transmit the same MBMS service.

Users access these services and obtain the MBMS content through wireless communication devices such as cellular phones, tablets, laptops, and other devices with wireless transceivers that communicate with the base station within the communication system. The base station provides wireless service to the wireless communication devices, sometimes referred to as mobile devices or UEs, within cells. A user can access at least some multimedia services through a UE using either a point-to-point (PTP) connection or a PTM transmission. In 3GPP systems, PTP services can be provided using unicast techniques and PTM transmissions can be provided using MBMS communication, transmitted over an MBSFN or single cell point to multipoint (SC-PTM) communication. In systems operating in accordance with a revision of 3GPP long term evolution (LTE) communication specification, MBMS is provided using eMBMS. Accordingly, an MBMS service can be provided using either unicast service, MBSFN, or SC-PTM in an LTE system.

In radio access network (RAN) meeting #88-e held during June 29, 2020 to July 3, 2020, a new working item was approved to target a RAN support of multicast/broadcast services (MBS) in 5G. Aims of this working item is to provide the support in RAN to enable general MBS services over 5GS to support different MBS services such as public safety and mission critical, V2X applications, transparent IPv4/IPv6 multicast delivery, IPTV, software delivery over wireless, group communications, and IoT applications. One of key objectives of this RAN working item is to study and specify the support for basic mobility with service continuity for 5G new radio (NR) multicast/broadcast services (MBS) .

During 3gpp RAN2#112e meeting, two modes were agreed for MBS delivery in R17. The first mode is the delivery mode, this mode is used for multicast session delivery and is applicable to UEs in an RRC connected state (FFS UEs in RRC inactive) and use both point-to-point (PTP) and point-to-multipoint (PTM) transmissions. The second delivery mode is delivery mode 2; this mode is used for broadcast session delivery, applicable to UEs in all RRC states and uses PTM transmissions only. For this mode, it was agreed in RAN2 113e that the UE is provided with an MBS configuration using a common RRC signalling in a two-step based approach (i.e., using a new SIB MBS to provide the transmission configuration of the multicast control channel (MCCH) which carries transmission scheduling configuration of MBS multicast traffic channel (MTCH) to the UE. It was also agreed that the scheduling of MCCH follows the same scheduling and an association of physical downlink control channel (PDCCH) monitoring occasions and synchronization signal blocks (SSBs) similar to that one used for other common control channels, e.g., broadcast control channel (BCCH) and paging control channel (PCCH) . Moreover, it was agreed that MCCH scheduling shall be done in a same bandwidth part (BWP) configured for other common control channels without a need of switching the BWP.

Under the above considerations, a network shall configure for a UE within the BWP configured for other common control channel, a control resource set (CORESET) , and a common search space for monitoring the MCCH in time domain resources (i.e., time slots) other than resources configured for the common control channel. Otherwise, the UE monitors search spaces of both MCCH and the other common control channel (i.e., BCCH and/or PCCH) simultaneously in the same time slot. This can relatively increase a UE reception complexity and it may also affect a scheduling of paging and system information which could impact normal operations of the UE.

Therefore, there is a need for a user equipment (UE) , a base station, and wireless communication methods, which can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

SUMMARY

An object of the present disclosure is to propose a user equipment (UE) , a base station, and a wireless communication method for multicast/broadcast service (MBS) , which can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

In a first aspect of the present disclosure, a wireless communication method for multicast/broadcast service (MBS) performed by a user equipment (UE) comprises receiving, from a base station, a configuration of frequency and time domain radio resources and a monitoring configuration. Then monitoring based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a system information (SI) channel, a paging channel, or a multicast control channel (MCCH) in a slot.

In a second aspect of the present disclosure, a wireless communication method for MBS performed by a base station comprises determining a configuration of frequency and time domain radio resources and a monitoring configuration for transmitting a PTM configuration message in MCCH along with a system information (SI) message in a BCCH channel and/or a paging message in PCCH channel. And transmitting, to a user equipment (UE) , the configuration of frequency and time domain radio resources and the monitoring configuration.

In a third aspect of the present disclosure, a user equipment (UE) comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The transceiver is configured to receive, from a base station, a configuration of frequency and time domain radio resources and a monitoring configuration. The processor is configured to monitor, based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a SI channel, a paging channel, or a multicast control channel (MCCH) in a slot.

In a fourth aspect of the present disclosure, a base station comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to determine a configuration of frequency and time domain radio resources and a monitoring configuration for transmitting a point-to-multipoint (PTM) configuration message in a multicast control channel (MCCH) along with a system information (SI) message in SI channel and/or a paging message transmitted over a paging channel in a same BWP. The transceiver is configured to transmit, to a user equipment (UE) , the configuration of frequency and time domain radio resources and the monitoring configuration.

In a fifth aspect of the present disclosure, a non-transitory machine-readable storage medium has stored thereon instructions that, when executed by a computer, cause the computer to perform the above method.

In a sixth aspect of the present disclosure, a chip includes a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the above method.

In a seventh aspect of the present disclosure, a computer readable storage medium, in which a computer program is stored, causes a computer to execute the above method.

In an eighth aspect of the present disclosure, a computer program product includes a computer program, and the computer program causes a computer to execute the above method.

In a ninth aspect of the present disclosure, a computer program causes a computer to execute the above method.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the embodiments of the present disclosure or related art more clearly, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 is a block diagram of one or more user equipments (UEs) and a base station (e.g., gNB) of communication in a communication network system according to an embodiment of the present disclosure.

FIG. 2 is a flowchart illustrating a wireless communication method for MBS performed by a UE according to an embodiment of the present disclosure.

FIG. 3 is a flowchart illustrating a wireless communication method for MBS performed by a base station according to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram illustrating an example of a wireless communication method for MBS performed by a base station and one or more UEs according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram illustrating an example of a wireless communication method for MBS performed by one or more UEs according to an embodiment of the present disclosure.

FIG. 6 is a schematic diagram illustrating an example of a wireless communication method for MBS performed by a base station according to an embodiment of the present disclosure.

FIG. 7 is a schematic diagram illustrating an example of a scheduling of a multicast channel and other common control channels based on a configuration of separate slots according to an embodiment of the present disclosure.

FIG. 8 is a schematic diagram illustrating an example of a scheduling of a multicast channel and other common control channels based on a modification period offset configuration according to an embodiment of the present disclosure.

FIG. 9 is a schematic diagram illustrating an example of a configuring UE to avoid reading or monitoring in a single time slot duration a multicast channel (MCCH) together with other common controls channel via an indication signal according to an embodiment of the present disclosure.

FIG. 10 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

Multicast/Broadcast Services (MBS) is expected to cover diversity of 5G applications and services ranging from public safety, mission critical, V2X, transparent IPv4/IPv6 multicast delivery, IPTV, software delivery over wireless to group communications, and IoT applications. In a latest discussion in 3GPP RAN meeting regarding a support of MBS in 3GPP R17 5G specification, it was agreed that a scheduling of a multicast control channel (MCCH) which is used for scheduling of MBS traffic channel and services, follows a scheduling and an association of PDCCH monitoring occasions with SSBs similar to that one used for other common control channels such as BCCH and PCCH and can be in same BWP configured for other common control channel for efficient scheduling and UE power saving. Under the above considerations, a network shall configure for a UE within the BWP configured for other common control channel, a control resource set (CORESET) , and a common search space for monitoring the MCCH in time domain resources (i.e., time slots) other than resources configured for the common control channel. Otherwise, the UE monitors search spaces of both MCCH and the other common control channel (i.e., BCCH and/or PCCH) simultaneously in the same time slot. This can relatively increase a UE reception complexity and it may also affect the scheduling of paging and system information which could impacts the normal operations of the UE.

During RAN Meeting #88-e (June 29 -July 3, 2020) a new working item was approved WID targeting the RAN support of Multicast/Broadcast Services (MBS) in 3gpp R17 5G specification. One of major requirement and objective of the WID is to specify RAN basic functions for MBS reception for UEs in RRC_IDLE/RRC_INACTIVE and connected states. This objective includes to specifying by RAN2 and RAN1 3gpp working group the required changes for R17 to enable the reception of Point to Multipoint (PTM) transmissions by UEs in RRC_IDLE/RRC_INACTIVE states while keeping the maximum commonality between RRC_CONNECTED state and RRC_IDLE/RRC_INACTIVE state for the configuration of PTM reception. During 3gpp RAN2#112e and RAN2 113e meetings two modes were agreed for MBS delivery in R17. The first mode is the delivery mode1 which is used for multicast session delivery and is applicable to UEs in RRC Connected state (FFS UEs in RRC Inactive) . For this mode the UE is provided with MBS configuration using dedicated RRC signalling when the UE is in RRC Connected state. This mode can use both Point-to-Point (PTP) and Point-to-Multipoint (PTM) transmissions. The second delivery mode is delivery mode1 which is used for broadcast session (FFS multicast session) delivery and is applicable to UEs in all RRC states. The UE is provided with MBS configuration using common RRC signalling in a two-step based approach, i.e. a new SIB for MBS will be used to provide the transmission configuration of MCCH. Based on the MCCH configuration received via SIB, UE reads MCCH, which carries transmission configuration of the MBS multicast traffic channel (MTCH) . This mode can use Point-to-Multipoint (PTM) transmissions only. For the second delivery mode, several consensus and agreements were achieved during RAN2 113bis as follow, regarding MCCH scheduling and configuration listed as follows. 1. The concept of MCCH transmission window, similar to the one used for LTE SC-PTM, is used for NR MCCH scheduling. 2. The MCCH transmission window is defined by MCCH repetition period, MCCH window duration and radio frame/slot offset. 3. A new RNTI is defined for scheduling MCCH. 4. A common search space (CSS) is needed for MCCH scheduling. 5. The common search space for MCCH are associated with PDCCH occasions and synchronization signal blocks (SSBs) in a pre-defined manner so that the UE can receive MCCH scheduling on PDCCH occasions according to its detected (SSB) .

Furthermore, due to the fact that MCCH is common channel that can be received by more than one UE, it is assumed that the common searchSpace#0 or other common search space can be configured for MCCH with the associated PDCCH monitoring occasions that mapped to SSBs using the same mapping rule for other common control channels (e.g.., the broadcast control channel (BCCH) which is used for scheduling of the system information (SI) messages and paging control channel (PCCH) which is used for scheduling the paging messages) . Moreover, it is also assumed that the search space for MCCH can be configured in the same BWP that configured for the other common control channel for efficient scheduling and UE power saving. Under the above considerations, a network shall configure for a UE within the BWP configured for other common control channel, a control resource set (CORESET) , and a common search space for monitoring the MCCH in time domain resources (i.e., time slots) other than resources configured for the common control channel. Otherwise, the UE monitors search spaces of both MCCH and the other common control channel (i.e., BCCH and/or PCCH) simultaneously in the same time slot. This can relatively increase UE reception complexity and it may also affect the scheduling of paging and system information which could impacts the normal operations of the UE. Some embodiments of this disclosure provide a scheduling mechanism to address the aforementioned problem.

To overcome the above problem, some embodiments of this disclosure provides a new scheduling mechanism that either separately schedules an MBS multicast control channel (MCCH) (which is used for transmitting MBS PTM configuration messages) and the other the common control channels such as a broadcast control channel (BCCH) (which is used for system information (SI) messages and paging control channel (PCCH) which is used for scheduling the paging messages) , or configures a UE to avoid receiving and monitoring these common control channels in during a single time slot duration. In this new exemplary method, a network determines an appropriate frequency and time domain radio resources configuration (e.g., common frequency resource (CFR) , bandwidth part (BWP) and time slot) and an appropriate monitoring configuration (e.g. CORESET, search space and the downlink RNTI configuration) for transmitting PTM configuration message in MCCH channel along with a system information (SI) message in BCCH and/or paging messages in a PCCH channel. The network sends appropriate radio resources and a monitoring configuration to the UE. The UE receives frequency and time resource domain as well as the monitoring configuration from the network. Then, the UE decides which the CORESET and search space and RNTI to monitor in each time slot based on the configuration provided by the network. After that UE monitors within a slot the decided COERESET, search space, and RNTI for receiving the specific common channel control channel (i.e., MCCH or BCCH or PCCH) .

Some embodiments of this disclosure provide a new scheduling mechanism for multicast control channel and other common control channels scheduling to support efficient reception of multicast/broadcast service transmitted over point to multi-point (PTM) configuration as well as the reception of other system information and paging notifications which are required for others UE normal operations. The major advantages of the new exemplary method compared to prior art include at least one of the followings: 1. The new exemplary method prevents a UE from monitoring of more than one control resource set (CORESET) , search space, and RNTI per time slot, while guaranteeing the scheduling of MCCH system information (SI) and paging channels in a same BWP without a need for UE BWP switching, which could result in a reduced network signalling overhead (i.e., signalling used for BWP switching) , a UE reception complexity, and a power consumption as required by 3GPP WID for R17 MBS. 2. The new exemplary method guarantees that the UE can only monitor only one CORESET, search space, and RNTIs per slot without or with very low additional singling overhead introduced to the UE. 3. The new exemplary method provide a flexible scheduling for an MCCH channel for the UE in both idle/inactive mode UE and connected mode UE and guarantee the requirement of commonality between the two states as per WID requirement.

In addition, if multicast channel is scheduling and follows without the same scheduling of the other common control channel, the UE may end up monitoring of more than one control resource set (CORESET) , search space, and RNTI per time slot. This could increase a UE reception complexity and may affect the scheduling of paging and system information which may impact UE normal operations. The obvious solution is to follow the same scheduling of the other common control channel for the multicast channel without introducing any mechanism to help preventing UE from monitoring of more than one control resource set (CORESET) , search space, and RNTI per time slot which could increase UE reception complexity and affects the scheduling of paging and system information. In some embodiments of the present disclosure, the new exemplary method prevents from the above issues.

FIG. 1 illustrates that, in some embodiments, one or more user equipments (UEs) 10 and a base station (e.g., gNB) 20 for communication in a communication network system 30 according to an embodiment of the present disclosure are provided. The communication network system 30 includes the one or more UEs 10 and the base station 20. The one or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The

processor

11 or 21 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of radio interface protocol may be implemented in the

processor

11 or 21. The

memory

12 or 22 is operatively coupled with the

processor

11 or 21 and stores a variety of information to operate the

processor

11 or 21. The

transceiver

13 or 23 is operatively coupled with the

processor

11 or 21, and the

transceiver

13 or 23 transmits and/or receives a radio signal.

The

processor

11 or 21 may include application-specific integrated circuit (ASIC) , other chipset, logic circuit and/or data processing device. The

memory

12 or 22 may include read-only memory (ROM) , random access memory (RAM) , flash memory, memory card, storage medium and/or other storage device. The

transceiver

13 or 23 may include baseband circuitry to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the

memory

12 or 22 and executed by the

processor

11 or 21. The

memory

12 or 22 can be implemented within the

processor

11 or 21 or external to the

processor

11 or 21 in which case those can be communicatively coupled to the

processor

11 or 21 via various means as is known in the art.

In some embodiments, the transceiver 13 is configured to receive, from the base station 20, a configuration of frequency and time domain radio resources and a monitoring configuration. The processor 11 is configured to monitor, based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a SI channel, a paging channel, or a multicast control channel (MCCH) in a slot. This can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

In some embodiments, the processor 21 is configured to determine a configuration of frequency and time domain radio resources and a monitoring configuration for transmitting a point-to-multipoint (PTM) configuration message in a multicast control channel (MCCH) along with a system information (SI) message in a SI channel and/or a paging message transmitted over a paging channel. The transceiver 23 is configured to transmit, to the UE 10, the configuration of frequency and time domain radio resources and the monitoring configuration. This can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

FIG. 2 illustrates a wireless communication method 200 for multicast/broadcast service (MBS) performed by a user equipment (UE) according to an embodiment of the present disclosure. In some embodiments, the method 200 includes: a block 202, receiving, from a base station, a configuration of frequency and time domain radio resources and a monitoring configuration, and a block 204, monitoring, based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a SI channel, a paging channel, or a multicast control channel (MCCH) in a slot. This can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

FIG. 3 illustrates a wireless communication method 300 for multicast/broadcast service (MBS) performed by a base station according to an embodiment of the present disclosure. In some embodiments, the method 300 includes: a block 302, determining a configuration of frequency and time domain radio resources and a monitoring configuration for transmitting a point-to-multipoint (PTM) configuration message in a multicast control channel (MCCH) along with a system information (SI) message in a SI channel and/or a paging message transmitted over a paging channel, and a block 304, transmitting, to a user equipment (UE) , the configuration of frequency and time domain radio resources and the monitoring configuration. This can solve issues in the prior art, reduce a signalling overhead, reduce a UE reception complexity, reduce a power consumption, provide a flexible scheduling of an MCCH for a UE, and/or provide a good communication performance.

In some embodiments, the common control (CC) comprises a broadcast control channel (BCCH) , the paging channel comprises a paging control channel (PCCH) , or the MCCH comprises an MBS MCCH. In some embodiments, the base station is configured to schedule separate slots on the SI channel, the paging channel, and/or the MCCH to allow the UE to receive and monitor one common control channel per time slot duration. In some embodiments, the base station is configured to configure a separate slot on a common frequency resource (CFR) or an initial downlink BWP (DL BWP) with one or more CORESETs each associated with one or more search spaces for monitoring a common downlink physical downlink (common-PDCCH) for a downlink control information (DCI) scrambled by a system information radio network temporary identifier (SI-RNTI) for BCCH scheduling or a DCI scrambled by a paging RNTI (P-RNTI) for PCCH channel scheduling; and/or the base station is configured to configure another separate/different slot on the same CFR or the same initial BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a point-to-multipoint (PTM) configuration message over the MCCH.

In some embodiments, the base station is configured to control the UE to perform a normal acquisition and a monitoring operation of the SI channel, the paging channel, or the MCCH and end up monitoring one search space or one RNTI per time slot. In some embodiments, the base station is configured to configure the CORESET and the search space for a multicast channel in radio frames other than radio frames configured with the CORESETs and the search space of common control channels. In some embodiments, the base station is configured to configure a modification period of a system information block (SIB) which carrying the SI channel or the paging channel with an offset with respect to the modification period of the SIB carrying MCCH and PTM configuration messages. In some embodiments, the base station is configured to control the UE to apply a same pre-defined equation using a system information block (SIB) configuration and end up acquiring and monitoring one search space for the SI channel, the paging channel, or the MCCH. In some embodiments, the wireless communication method further comprises configuring, to the UE, an indication signal, wherein the indication signal indicates the CORESET and the search space for the UE to monitor for each time slot, such that the base station is configured to control the UE to avoid reading and monitoring the CORESET and the search space of the MCCH together with the CORESET and the search space of the SI channel or the paging channel in a same slot.

In some embodiments, the base station is configured to configure a separate slot on a CFR or an initial BWP with one or more CORESETs each associated with one or more search spaces for monitoring a common-PDCCH for a DCI scrambled by an SI-RNTI for BCCH scheduling or a DCI scrambled by a P-RNTI for PCCH channel scheduling; and/or the base station is configured to configure another separate/different slot on the same CFR or the same initial DL BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a PTM configuration message over the MCCH.

In some embodiments, the base station configures the UE to avoid monitoring the CORESET and the search space of multicast channel (MCCH) together with the CORESETs and search spaces of other common control channel (BCCH and PCCH) in a same slot by providing an explicitly signalling indicating which CORESETs and search spaces UE have to monitor for each specific time slot. In some embodiments the base station transmits the indication signal to the UE via a spare bit within a master information block (MIB) information element along with parameters required to decode a system information block type1 SIB1. In some embodiments, the base station transmits the indication signal to the UE via a new configured field within a PDCCH common configuration information element (IE) which is carried by an SIB1. In some embodiments, for the spare bit within the MIB or the new configured field within the SIB1, a configuration can be in a way that if a field is a first value, the base station controls the UE to monitor the CORESER and/or the search space for the system information or the BCCH for the PDCCH with the DCI scrambled by the SI-RNTI, if the field is a second value, the base station controls the UE to monitor the CORESER and/or the search space for paging, the PCCH, or the PDCCH with the DCI scrambled by the PI-RNTI, and if the field is the first value, the UE monitors the CORESER and/or the search space for the MCCH, or the UE monitors the PDCCH with the DCI scrambled by the MCCH-RNTI.

FIG. 4 illustrates an example of a wireless communication method for MBS performed by a base station and one or more UEs according to an embodiment of the present disclosure. FIG. 5 illustrates an example of a wireless communication method for MBS performed by one or more UEs according to an embodiment of the present disclosure. FIG. 6 illustrates an example of a wireless communication method for MBS performed by a base station according to an embodiment of the present disclosure. FIG. 4 to FIG. 6 illustrate that, in some embodiments, to overcome the problem described in the above section and help preventing a UE from monitoring of more than one a control resource set (CORESET) , a search spaces and a radio network identifier (RNTI) at every time slot duration. Some embodiments of this disclosure provides a new scheduling mechanism that either separately schedule the MBS multicast control channel (MCCH) (which used for transmitting the MBS PTM configuration messages) and the other the common control channels such as the broadcast control channel (BCCH) (which is used for system information (SI) messages and paging control channel (PCCH) which is used for scheduling the paging messages) , or configure UE to avoid receiving and monitoring these common control channels in during a single time slot duration. In this new exemplary method, a network determines the appropriate frequency and time domain radio resources configuration (e.g., common frequency resource (CFR) , bandwidth part (BWP) and time slot) and the appropriate monitoring configuration (e.g., CORESET, search space and the downlink RNTI configuration) for transmitting PTM configuration message in MCCH channel along with the system information (SI) message in BCCH and/or the paging messages in PCCH channel. The network sends the appropriate radio resources and the monitoring configuration to UE. The UE receives the frequency and time resource domain as well as the monitoring configuration from the network. Then, the UE decides which the CORESET and search space and RNTI to monitor in each time slot based on configuration provided by the network. After that UE monitors within a slot the decided COERESET, search space, and RNTI for receiving the specific common channel control channel (i.e., MCCH or BCCH or PCCH) as illustrated in FIG. 4, FIG. 5, and FIG. 6.

In some embodiments of this disclosure, the major advantages of the new scheduling mechanism include at least one of the followings: 1. The new exemplary method prevents a UE from monitoring of more than one control resource set (CORESET) , search space, and RNTI per time slot, while guaranteeing the scheduling of MCCH system information (SI) and paging channels in same BWP without a need for UE BWP switching, which could result in a reduced network signalling overhead (i.e., signalling used for BWP switching) and UE reception complexity and power consumption as required by the 3GPP WID for R17 MBS. 2. The new exemplary method guarantees that the UE can only monitors only one CORESET) and search space and RNTIs per slot without or with very low additional singling overhead introduced to UE. 3. The new exemplary method provides a flexible scheduling for MCCH channel for UE in both idle/inactive and connected mode UE and guarantee the requirement of the commonality between the two state as per WID requirement.

In some embodiments, in the exemplary method provided above, the determining of the appropriate frequency and time domain radio resources configuration and the appropriate monitoring configuration for multicast channel (MCCH) and the other common control channels comprises at least one of the followings: 1. Scheduling the separate slots each of the multicast channel (MCCH) and other common control channels (like BCCH and PCCH) to allow UE receiving and monitoring only one common control channel per time slot duration. 2. Configuring UE to avoid reading or monitoring in single time slot duration the multicast channel (MCCH) together with the other common controls channel (like BCCH and PCCH) via an indication signal. 3. In the exemplary method provided above, the appropriate radio resources and monitoring configuration to UE comprise sending radio resources and monitoring configuration only or radio resources and monitoring configuration together with an indication message that indicates to UE which search space to monitor during each specific time slot.

Separately scheduling of the multicast channel and other common control channels:

For this exemplary option, a network implicitly configures a UE to avoid monitoring of the multicast control channel together with the others common channels (like BCCH and PCCH) within a same time slot by one of the following options A and B:

Option A:

FIG. 7 illustrates an example of a scheduling of a multicast channel and other common control channels based on a configuration of separate slots according to an embodiment of the present disclosure. In the option A: Configuring in a separate slot on a common frequency resources (CFR) or an initial BWP with one or more CORESETs (CR) each associated with one or more search spaces (SS) for monitoring the common downlink physical downlink (common-PDCCH) for a downlink control information (DCI) scrambled by system information RNTI (SI-RNTI) for BCCH scheduling or a DCI scrambled by paging RNTI (P-RNTI) for PCCH channel scheduling is provided. Configuring a in another separate/different slot the same common frequency resources (CFR) or initial DL BWP with a CORESET (CR) associated with one or more search spaces (SS) for monitoring common-PDCCH with DCI scramble by MCCH-RNTI for scheduling of PTM configuration message over MCCH is provided.

As illustrated by the example given in FIG. 7, where the network is capable of configuring the UE with an initial downlink BWP (DL BWP) . within this DL BWP, it configures three CORESETs (or common PDCCH decode regions) (CR0, CR1 and CR2) with their associated search spaces (SS0, SS1, and SS2) for the system information channel BCCH, the paging channel PCCH and multicast control channel MCCH respectively. To help avoiding the UE from monitoring more than one of these CORESET and search space in a slot, the network may pre-configure the scheduling of SI channel (e.g., MIB or SIB) in first time slot (slot0) (CR0: SS0: SI-RNTI) . In addition, re-configure the scheduling of the paging channel in second slot (slot1) (CR1: SS1: P-RNTI) , and pre-configures the scheduling of MCCH channel in the third time slot (slot2) (CR0: SS2: MCCH-RNTI) . In this way even if the UE blindly monitor the time slot for CORESETs and search spaces, it can end up monitoring only one CORESET and search space at time as shown in the table provided within FIG. 7.

Option B:

FIG. 8 illustrates an example of a scheduling of a multicast channel and other common control channels based on a modification period offset configuration according to an embodiment of the present disclosure. In the option B: Configuring of the CORESET and the search space for multicast channel in the radio frames other than the radio frames configured with the CORESETs and the search space of common control channels is provided. This can be done by the network by configuring of the modification period of the system information block (SIB) which carrying the common BCCH and/or the PCCH channels with an offset with the respect to modification period used by the SIB carrying that MCCH and PTM configuration messages.

Further, in a latest 3ggp meeting regarding NR MBS, it was agreed that the scheduling of the MCCH channel shall adopt a two-step based scheduling approach similar to LTE single cell PTM (SC-PTM) (i.e. by providing on a new MBS specific SIB carried by the broadcast control channel (BCCH) , the scheduling configuration of MCCH channel. As in LTE SC-PTM, the scheduling of the SIB carrying MCCH scheduling uses a modification period configuration (i.e., which is defined by SFN mod M=0, where m is the number of radio frames comprising the modification period of MCCH) ; just same as the modification period configuration used for scheduling of SI message update on BCCH and/or PCCH in NR (i.e., which is also based on SFN mod m = 0, where m is the number of radio frames comprising the modification period of SI message within in BCCH or PCCH channels) . To achieve the goal of scheduling the CORESET and the search space for multicast channel in the radio frames other than the radio frames configured with the CORESETs and the search spaces of the other common control channels (BCCH, PCCH) , an offset can be configured by the network in a way that if the scheduling of the SIB used for other common control channels (BCCH, PCCH) scheduling is configured with SFN mod M=0, the scheduling of the SIB carrying MCCH configuration shall be configured for example with SFN mode M= x, where x is a radio frame offset from SIB other common control channel (as shown in Figure 5) . In this way, from the UE side, the monitoring configuration of search space for other common control channel (i.e., BCCH and PCCH) can be in different time domains with the respect to the monitoring configuration of the MCCH search space.

For the both above configuration options no additional signalling is needed to be provided by the network to UE. In the first option, the UE may perform the normal acquisition and monitoring operation of SI/paging/MCCH and end up monitoring only one search spaces or RNTI per time slot. As for the second option, the UE may apply the same pre-defined equation used SIB configuration and end up acquiring and monitoring only one search space for either MCCH or others common channel.

Configuring UE to avoid monitoring multicast channel together with other common control channel via indication signal:

For this exemplary option, the network configures the UE to avoid reading and monitoring the CORESET and search space of multicast channel (MCCH) together with the CORESETs and search spaces of other common control channel (BCCH and PCCH) in a same slot by providing an explicitly signalling indicating which CORESETs and search spaces UE have to monitor for each specific time slot. This can be done by Configuring in a separate slot a common frequency resources (CFR) or an initial BWP with one or more CORESETs (CR) each associated with one or more search spaces (SS) for monitoring the common downlink physical downlink (common-PDCCH) for a DCI scrambled by system information RNTI (SI-RNTI) for BCCH scheduling or a DCI scrambled by paging RNTI (P-RNTI) for PCCH channel scheduling; and configuring in the same slot and the same common frequency resources (CFR) or initial BWP with a CORESET (CR) associated with one or more search spaces (SS) for monitoring common-PDCCH with DCI scramble by MCCH-RNTI for scheduling of PTM configuration message over MCCH. Then, providing a singling that indicates to a UE, which CORESET and search space have to monitor among the configured CORESETs and search spaces for this specific time slot.

For indicating which CORESETs and search space a UE have to monitor within a time slot, there are two options. 1. The first one is to provide the indication via the spare bit within Master Information Block (MIB) information element along with the parameters required to decode System Information block Type1 SIB1 (i.e., providing it within CORESET0) as shown in Table 1.

Table 1: Indication via MIB Information element

The second one is to provide the indication via a new defined one bit field (NewDifindedField) within PDCCH common configuration Information element (IE) (PDCCH-ConfigCommon IE) which is carried by SIB1 (as shown in Table 2) .

Table 2: Indication via SIB1 Information element: PDCCH-ConfigCommon

FIG. 9 illustrates an example of a configuring UE to avoid reading or monitoring in a single time slot duration a multicast channel (MCCH) together with other common controls channel via an indication signal according to an embodiment of the present disclosure. For these above two options: The spare bit within MIB or new configured field within SIB1, the configuration can be in a way that if the field is 1, the UE can monitor the CORESER/Search space for system information or BCCH for PDCCH with DCI scrambled by SI-RNTI, if the field is 0, the UE can monitor the CORESER/Search space for paging or PCCH or PDCCH with DCI scrambled by PI-RNTI, and if the field is 1, the UE can monitor the CORESER/Search space for or MCCH or monitor a PDCCH with DCI scrambled by MCCH-RNTI. Table 3 shows an example of the indication signal which can be provided by the network to the UE and FIG. 9 shows the monitoring configuration of a different time slot according to provided signal.

Table 3: The indication signal which can be provided by the network to the UE

The common search space (such as those one configured for BCCH, PCCH, or MCCH) are specific search spaces that every UE need to search for signaling message that is applied to every UE (e.g., PDCCH for SIB) . Each of these search space represents a set of control channel elements (CCEs) at a different aggregation level (s) . In other words, these search spaces are used to tell how many PDCCH candidates are configured for UE to decode at different aggregation level. Within each of these search spaces, a UE can perform blind decoding to know the aggregation level, the position of the PDCCH within the set of CCEs, or the format, size of the DCI. To help limit the processing requirement of the UE, 3GPP provides in Table 4 [TS 38.213] which shows the maximum number of PDCCH candidates for a UE to monitor per slot for the operation in single serving cell with overlapped and non-overlapped CCEs (i.e., different subcarrier spacing (SCS) configuration or μ value are given in this table) .

Table 4: The maximum number of the monitored PDCCH candidates by UE per slot

According to the provided table (i.e. Table 4) , we can notice that for example for 15 khz subcarrier spacing (i.e. μ=0) , if UE is configured by the network to monitor the search spaces configured for multicast control channel (MCCH) , paging channel (PCCH) and the broadcast channel (BCCH) tougher within a same time slot. Then, the total number of the monitored PDCCH candidates would be 3*44 for overlapped CCEs or 3*56 for non-overlapped CCEs configuration. According the method provided within this disclosure, at each time slot duration the UE will be configured only monitor one channel only (MCCH or BCCH/PCCH) ; therefore, total number of the monitored PDCCH candidates would be only 44 or 56 PDCCH candidates per slot. This can relatively reduce UE reception complexity and save UE power.

In summary, some embodiments of this disclosure have discussed a new scheduling mechanism for multicast control channel and other common control channels scheduling to support efficient reception of multicast/broadcast service transmitted over point to multi-point (PTM) configuration as well as the reception of other system information and paging notifications which are required for others UE normal operations. The major advantages of the new exemplary method compared to prior art include at least one of the followings: 1. The new exemplary method prevents a UE from monitoring of more than one control resource set (CORESET) , search space, and RNTI per time slot, while guaranteeing the scheduling of MCCH system information (SI) and paging channels in a same BWP without a need for UE BWP switching, which could result in a reduced network signalling overhead (i.e., signalling used for BWP switching) , a UE reception complexity, and a power consumption as required by 3GPP WID for R17 MBS. 2. The new exemplary method guarantees that the UE can only monitor only one CORESET, search space, and RNTIs per slot without or with very low additional singling overhead introduced to the UE. 3. The new exemplary method provide a flexible scheduling for an MCCH channel for the UE in both idle/inactive mode UE and connected mode UE and guarantee the requirement of commonality between the two states as per WID requirement.

FIG. 10 is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. Embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. FIG. 10 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, an application circuitry 730, a memory/storage 740, a display 750, a camera 760, a sensor 770, and an input/output (I/O) interface 780, coupled with each other at least as illustrated. The application circuitry 730 may include a circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combination of general-purpose processors and dedicated processors, such as graphics processors, application processors. The processors may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems running on the system.

While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

A wireless communication method for multicast/broadcast service (MBS) performed by a user equipment (UE) , comprising:

receiving, from a base station, a configuration of frequency and time domain radio resources and a monitoring configuration; and

monitoring, based on the configuration of frequency and time domain radio resources and the monitoring configuration, a control resource set (CORESET) and a search space for a common control (CC) channel in a slot.
The wireless communication method of claim 1, wherein the common control (CC) channel comprises a broadcast control channel (BCCH) , a paging channel comprising a paging control channel (PCCH) , or a multicast control channel (MCCH) comprising an MBS MCCH.
The wireless communication method of claim 2, wherein separate slots are configured for scheduling of the system information (SI) channel, the paging channel, or the MCCH to allow the UE to receive and monitor one common control channel per time slot duration.
The wireless communication method of claim 3, wherein a separate slot is configured on a common frequency resource (CFR) or an initial downlink bandwidth part (DL BWP) with one or more CORESETs each associated with one or more search spaces for monitoring a common downlink physical downlink (common-PDCCH) for a downlink control information (DCI) scrambled by a system information radio network temporary identifier (SI-RNTI) for BCCH scheduling; or monitoring a DCI scrambled by a paging RNTI (P-RNTI) for PCCH channel scheduling; and

another separate/different slot is configured on the same CFR or the same initial BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a point-to-multipoint (PTM) configuration message over the MCCH.
The wireless communication method of claim 4, wherein the UE is configured to perform a normal acquisition and a monitoring operation of the SI channel, the paging channel, or the MCCH and end up monitoring one search space or one RNTI per time slot.
The wireless communication method of claim 3, wherein the CORESET and the search space are configured for a multicast channel in radio frames other than radio frames configured with the CORESETs and the search space of common control channels.
The wireless communication method of claim 6, wherein the UE is configured to apply a same pre-defined operations by a system information block (SIB) configuration and end up acquiring and monitoring one search space for the SI channel, the paging channel, or the MCCH.
The wireless communication method of claim 1, further comprising being configured, by the base station, with an indication signal, wherein the indication signal indicates the CORESET and the search space for the UE to monitor for each time slot; such that the UE is configured to avoid reading and monitoring CORESET and search space of MCCH together with CORESETs and search spaces of SI or paging channel in a same slot.
The wireless communication method of claim 8, wherein a separate slot is configured on a CFR or an initial DL BWP with one or more CORESETs each associated with one or more search spaces for monitoring a common-PDCCH for a DCI scrambled by an SI-RNTI for BCCH scheduling or a DCI scrambled by a P-RNTI for PCCH channel scheduling; and another separate/different slot is configured on the same CFR or the same initial BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a PTM configuration message over the MCCH.
The wireless communication method of claim 9, wherein the UE receives the indication signal from the base station via a spare bit within a master information block (MIB) information element along with parameters required to decode a system information block type1 SIB1.
The wireless communication method of claim 9, wherein the UE receives the indication signal from the base station via a new configured field within a PDCCH common configuration information element (IE) which is carried by an SIB1.
The wireless communication method of claim 10 or 11, wherein the configuration for the spare bit within the MIB or the new configured field within the SIB1 can be in a way that:

if a field is a first value, the UE monitors the CORESER and/or the search space for the system information or the BCCH for the PDCCH with the DCI scrambled by the SI-RNTI;

if the field is a second value, the UE monitors the CORESER and/or the search space for paging, the PCCH, or the PDCCH with the DCI scrambled by the PI-RNTI; and

if the field is the first value, the UE monitors the CORESER and/or the search space for the MCCH, or the UE monitors the PDCCH with the DCI scrambled by the MCCH-RNTI.
A wireless communication method for multicast/broadcast service (MBS) performed by a base station, comprising:

determining a configuration of frequency and time domain radio resources and a monitoring configuration for transmitting a point-to-multipoint (PTM) configuration message in a common multicast control channel (MCCH) along other common control (CC) channel in a same BWP; and

transmitting, to a user equipment (UE) , the configuration of frequency and time domain radio resources and the monitoring configuration.
The wireless communication method of claim 13, wherein the other CC channels comprises a broadcast control channel (BCCH) which used for scheduling of the system information (SI) messages and/or a paging control channel which used for scheduling of paging messages.
The wireless communication method of claim 13, wherein the base station is configured to configure separate slots for SI channel, paging channel, and the MCCH to allow the UE to receive and monitor only one common control (CC) channel per time slot duration.
The wireless communication method of claim 15, wherein the base station is configured to configure a separate slot on a common frequency resource (CFR) or an initial bandwidth part (BWP) with one or more CORESETs each associated with one or more search spaces for monitoring a common downlink physical downlink (common-PDCCH) for a downlink control information (DCI) scrambled by a system information radio network temporary identifier (SI-RNTI) for BCCH scheduling or a DCI scrambled by a paging RNTI (P-RNTI) for PCCH channel scheduling; and

the base station is configured to configure another separate/different slot on the same CFR or the same initial BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a point-to-multipoint (PTM) configuration message over MCCH.
The wireless communication method of claim 16, wherein the base station is configured to control the UE to perform a normal acquisition and a monitoring operation of the SI channel, the paging channel, or the MCCH and end up monitoring one search space or one RNTI per time slot.
The wireless communication method of claim 15, wherein the base station is configured to configure the CORESET and the search space for a multicast channel in radio frames other than radio frames configured with the CORESETs and the search space of common control channels.
The wireless communication method of claim 18, wherein the base station is configured to configure a modification period of a system information block (SIB) which carrying the SI channel and/or the paging channel with an offset with respect to the modification period of the SIB carrying MCCH and PTM configuration messages.
The wireless communication method of claim 18, wherein the base station is configured to control the UE to apply a same pre-defined operations of a system information block (SIB) reception and end up acquiring and monitoring one search space for either for the SI channel, the paging channel, or the MCCH per slot.
The wireless communication method of claim 13, further comprising configuring, to the UE, an indication signal, wherein the indication signal indicates the CORESET and the search space for the UE to monitor for each time slot, such that the base station is configured to control the UE to avoid reading and monitoring the CORESET and the search space of the MCCH together with the CORESET and the search space of the SI channel or the paging channel in a same slot.
The wireless communication method of claim 21, wherein the base station is configured to configure a separate slot on a CFR or an initial BWP with one or more CORESETs each associated with one or more search spaces for monitoring a common-PDCCH for a DCI scrambled by an SI-RNTI for BCCH scheduling or a DCI scrambled by a P-RNTI for PCCH channel scheduling; and/or the base station is configured to configure another separate/different slot on the same CFR or the same initial BWP with one CORESET associated with one or more search spaces for monitoring the common-PDCCH with the DCI scramble by an MCCH-RNTI for scheduling of a PTM configuration message over the MCCH.
The wireless communication method of claim 21, wherein the base station transmits the indication signal to the UE via a spare bit within a master information block (MIB) information element along with parameters required to decode a system information block type1 SIB1.
The wireless communication method of claim 22, wherein the base station transmits the indication signal to the UE via a new configured field within a PDCCH common configuration information element (IE) which is carried by an SIB1.
The wireless communication method of claim 23 or 24, wherein for the spare bit within the MIB or the new configured field within the SIB1, a configuration can be in a way that;

if a field is a first value, the base station controls the UE to monitor the CORESER and/or the search space for the system information or the BCCH for the PDCCH with the DCI scrambled by the SI-RNTI;

if the field is a second value, the base station controls the UE to monitor the CORESER and/or the search space for paging, the PCCH, or the PDCCH with the DCI scrambled by the PI-RNTI; and

if the field is the first value, the UE monitors the CORESER and/or the search space for the MCCH, or the UE monitors the PDCCH with the DCI scrambled by the MCCH-RNTI.
A user equipment (UE) , comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to execute the method of any one of claims 1 to 12.
A base station, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to execute the method of any one of claims 13 to 25.
A non-transitory machine-readable storage medium having stored thereon instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 25.
A chip, comprising:

a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the method of any one of claims 1 to 25.
A computer readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute the method of any one of claims 1 to 25.
A computer program product, comprising a computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 25.
A computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 25.