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The system information in 5G(NR) consists of MIB (Main Information Block) and SIB (System Information Block), which are broadcasted to the coverage area through the wireless system to convey network and system related information to the terminal devices in the cell. This information plays an important role in the initial establishment, configuration and maintenance of the terminal (UE) and the network pass; the specific functions are as follows:   I. MIB (Master Information Block) It is the initial reference point for 5G terminals (UEs) to enter a new cell or network area, and provides wireless terminals (UEs) with basic information about the cell such as: cell identification, physical layer configuration, and the system frame number (SFN).The MIB frequency and timing information includes; details about the carrier frequency and timing information required for synchronization as well as resources required to allow the UE to synchronize with and access the network. Resources.   II. SIBs (System Information Blocks) contain more and more detailed information content about the network, cells and available services. They are broadcast periodically, allowing the terminal (UE) to update its understanding of network parameters and optimize its communication settings.   III.SIB Message Types It has many types, each with a specific purpose. For example, SIB1 message provides necessary cell reselection information, SIB2 contains information about cell access, SIB3 provides detailed information about cell selection and so on.   IV.DYNAMIC CONFIGURATION INFORMATION SIB messages may also include dynamic information related to changes in network configuration, neighboring cells, and system-related parameters to allow the terminal (UE) to adapt to changing network conditions.   V. BROADCASTING MECHANISMS Both MIB and SIB1 are broadcast periodically by the cell; other SIB messages allow the terminal (UE) to obtain and update the necessary information through a request mechanism without the need for continuous broadcasting. This mechanism is essential to optimize power consumption and ensure fast access to network resources.   VI.INITIAL ACCESS AND CELL SELECTION When a terminal (UE) tries to connect to a new cell, MIB messages are crucial in the initial access phase. By quickly obtaining information from the MIB, the UE can synchronize with the cell and initiate the cell selection process. SIB1 then provides additional details used to fine-tune the connection parameters.   VII. Switching and Mobility SIB messages play a role in the switching process by providing information about neighboring cells. The terminal (UE) uses this information to make informed decisions during switching and to ensure seamless transitions between cells while moving within the network.   VIII.Dynamic Configuration of the Network SIB messages allow dynamic configuration of the network, enabling operators to adjust parameters, introduce new services and modify network settings without having to communicate directly with each terminal (UE). This flexibility simplifies network management and updates.   IX.Different Services Support SIB messages are intended to support the requirements of different services and applications. They may include information about network slices, quality of service (QoS) parameters, and service-specific related details to enable the endpoint (UE) to adapt its behavior to the service requirements.   MIBs and SIBs in 5G are key components of the broadcast information system, providing terminals (UEs) with essential detailed information for initial access, cell selection, switching and dynamic adaptation to changing network conditions. Their efficient broadcast mechanisms ensure that the terminal (UE) can quickly synchronize with the network and reliably access and optimize the information needed for communication.

Cell Barred in 5G (NR) systems refers to restricting or prohibiting a mobile device (UE) from accessing a specific cell in the network. This restriction, for various reasons, is also an operational mechanism controlled by the network to manage and control the access of user equipment to a specific cell. The main reasons for turning on Cell Barred (access prohibition) are as follows;   I. ACCESS CONTROL MECHANISMS Cell banning is an access control mechanism implemented by the network to specify which devices can connect to a particular cell and under what conditions.   II.Cell blocking may be triggered by different factors, such as network congestion, maintenance activities, security issues or specific operational policies defined by the network operator. In addition, during maintenance work on a particular cell or when the cell is heavily congested, the network operator may decide to block access to the cell in order to prevent unintended connections and ensure network stability.   III.Cell prohibition types can be applied in different situations in 5G networks, including: access prohibition, re-selection prohibition and access and re-selection prohibition;   * Access prohibition prevents new devices from connecting to a prohibited cell; while reselection prohibition restricts existing connected devices from reselecting a prohibited cell during switching or reselection.   * Timer-based prohibition in cell prohibition typically involves the use of a timer; the network may decide to prohibit terminal (UE) access to the cell for a specific period of time, after which the restriction will be lifted. Timer-based cell barring allows for temporary restrictions, ensuring that terminal devices are barred from the cell only for the necessary time.   IV. Network Management Enhancements Cell blocking is a tool for network operators to dynamically manage and optimize the use of network resources. It helps prevent overloading of specific cells to ensure a balanced distribution of traffic.   V. Terminals (UEs) and Cell Barred When a cell is barred, the network (NG-RAN) communicates the relevant information to the subscribers (UEs) via a system message. Upon receiving the barred information, the terminals (UEs) will comply with the restriction and refrain from attempting to access or reselect an unbarred cell.   Cell Barred for 5G is the temporary restriction or prohibition of user devices from accessing specific cells within the wireless network; this mechanism is used for network management purposes to ensure stability, efficiency and optimal performance of the 5G (NR) network.  

I. MBS Service Reception A 5G terminal (UE) may be configured to receive data from an MBS multicast session only in the RRC_CONNECTED or RRC_INACTIVE state. Instead, to receive multicast services, the UE needs to perform the MBS session join procedure specified in TS 23.247 [45]. It is up to the gNB to decide whether the UE receives data from the MBS multicast session in the RRC_CONNECTED state or in the RRC_ INACTIVE state. gNB moves the UE from the RRC_CONNECTED state to the RRC_INACTIVE state by means of the RRCRelease message and from the RRC_INACTIVE state by means of the group notification or UE specific paging. INACTIVE state and moves the UE from the RRC_CONNECTED state through group notification or UE-specific paging.   II. Terminal RRC state If the UE joining a multicast session is in the RRC_CONNECTED state and when the multicast session is activated, the gNB may send an RRC Reconfiguration message to the UE with the MBS configuration related to the multicast session. If the gNB configures the UE to receive MBS multicast sessions in the RRC_INACTIVE state, the gNB may provide the PTM configuration for the MBS multicast session and information on which multicast services may continue to be received in the RRC_INACTIVE state via the RRCRelease message. the UE does not suspend the MBS services indicating that the multicast sessions continued in the RRC_INACTIVE state. MRBs for received multicast sessions. the multicast MCCH is used if the cell supports PTM updates or provides PTM configuration to UEs moving from other cells in the RRC_INACTIVE state. otherwise the presence of a multicast MCCH is optional.   III.Notification Mechanism Used to announce changes in the content of the multicast MCCH due to multicast session modification or session deactivation or due to neighboring cell information modification. The scheduling information received by the multicast MCCH will be provided via SIB24 and may also be provided via an RRCRelease message.   IV.MBS No Data Handling The gNB may move the UE to the RRC_INACTIVE state when the active multicast session has no data to be sent to the UE for the time being. When the MBS multicast session is deactivated the gNB can move the RRC_CONNECTED state UE to RRC_IDLE or RRC_INACTIVE state. For a UE receiving MBS multicast session data in the RRC_INACTIVE state, the gNB notifies the UE to stop listening to the corresponding G-RNTI-addressed PDCCH via an RRCRelease message or a multicast MCCH when there is no data to be sent for the time being, or the session has been deactivated. gNBs supporting MBS use a group notification mechanism to notify the UE in the RRC_IDLE or RRC_INACTIVE state when the CN has activated a multicast session. RRC_IDLE or RRC_INACTIVE state. gNBs that support MBS use the group notification mechanism to notify UEs in the RRC_INACTIVE state when a session has been activated and the gNB has multicast session data to be transmitted. if UEs receiving data for MBS multicast sessions that are in the RRC_INACTIVE state in the cell are notified to stop Monitoring of PDCCHs addressed by G-RNTI for all joined multicast sessions. the UE does not monitor PDCCHs addressed by multicast-MCCH-RNTI until it receives a group notification. Upon receipt of the group notification, the UE reconnects to the network or restores the connection and transitions from the RRC_IDLE state or the RRC_INACTIVE state to the RRC_CONNECTED state. Upon receipt of a group notification indicating that multicast reception is allowed in the RRC_INACTIVE state, the UE remains in the RRC_INACTIVE state and acts as specified in TS 38.331 [12]. If the UE receives notification of both the group notification and the UE specific paging, the UE follows the specific paging and enters the RRC_CONNECTED state.   V. Terminal Addressing Group notification addresses the terminal (UE) through P-RNTI on the PDCCH, and the paging channel is monitored by the UE. The paging message of the group notification contains the MBS session ID, which is used to page all UEs in the RRC_IDLE and RRC_INACTIVE states that have joined the relevant MBS multicast session, i.e., without paging the UEs individually.When the UE enters the RRC_CONNECTED state, the UE stops monitoring the group notification related to a specific multicast session, i.e., it stops checking for MBS session IDs in the paging message. Session ID. in these cases. i.e. the UE does not monitor group notifications once this UE leaves this multicast session or the network requests the UE to leave or the network releases the multicast session.   VI. Paging Terminal If a UE in the RRC_IDLE state that joins an MBS multicast session resides on a gNB that does not support MBS, the UE may receive CN-initiated paging notifications in which the CN pages each UE individually due to session activation or data availability. if a UE in the RRC_INACTIVE state that joins an MBS multicast session resides on a gNB that supports MBS, the UE may be notified individually via RAN-initiated paging due to session activation or data availability. gNB, the UE may be notified individually via RAN-initiated paging due to session activation or data availability.   NOTE: The gNB's decision to keep the UE in the RRC_CONNECTED state (e.g., in order to meet the latency requirements of a mission-critical service) or to move the UE to the RRC_INACTIVE or RRC_IDLE state (e.g., when there is no data to be sent to the UE for the time being or in order to address cell congestion) may take into account the 5QI values of the mission-critical and the non-mission-critical UEs or the other QoS parameters.

I. Service Continuity The mobility of the terminal (UE) in the multicast service (MBS) supported by 5G is, in principle, the same as that of other services in the 5G (NR) system.   II.MULTICAST SWITCHING The mobility procedure for multicast reception allows the UE to continue to receive multicast services via PTM or PTP in the new cell after switchover; where:   2.1 The source gNB transmits to the target gNB during the switchover preparation phase the UE context information of the MBS multicast sessions to which the UE has joined. in order to support the provision of local multicast services with location-dependent content (as described in TS 23.247 [45]) for each active multicast session, the target gNB may be provided with the service area information for each regional session ID. The source gNB may propose data forwarding for certain MRBs to minimize data loss and may exchange the corresponding MRB PDCP sequence numbers with the target gNB during switchover preparation:   * If the UE is configured with a PTP RLC AM entity in the target cell MRB, the MBS supports inter-cell switching and lossless switching of multicast services regardless of whether the UE is configured with a PTP RLC AM entity in the source cell.   * To support lossless switching of multicast services, the network shall ensure synchronization and continuity of the DL PDCP COUNT values between the source and target cells. Additionally PDCP status reports from the source gNB to the target gNB data forwarding and/or UE for the multicast session MRB may be used during lossless switching.   2.2 Multicast Session Processing For each multicast session that is undergoing user data transfer:   * If MBS session resources do not exist on the target gNB, the target gNB triggers the setting of MBS user-plane resources to the 5GC using the NGAP distribution setup procedure.   * If unicast transmission is used, the target gNB provides the DL tunnel endpoint to be used for the MB-SMF.   * If multicast transport is used, the target gNB receives the IP multicast address from the MB-SMF.   2.3 Switchover execution The MBS configuration decided by the target gNB during the period is sent to the UE via the source gNB within the RRC container (as described in TS38.331 [12]). the PDCP entity of the multicast MRBs in the UE may be re-established or may remain as it is. When the UE connects to the target gNB, the target gNB sends an indication to the SMF that it is an MBS supporting node in a Path Switching Request message (Xn Switching) or Switching Request Confirmation message (NG Switching).   2.4 After successful switchover completion For any multicast session with no remaining joining UEs in the gNB, the source gNB may trigger the release of MBS user plane resources to the 5GC using the NGAP distribution release procedure.    

Before a wireless end device (UE) can communicate it first selects the network it supports access to; in the 5G (NR) system the UE either selects a PLMN or an SNPN; its exactly how this is done.   Ⅰ. PLMN Selection When not operating in SNPN access mode, the terminal's (UE's) access (AS) in the wireless network shall report the available PLMNs and any associated CAG-IDs to the NAS upon NAS request or autonomously; whereas when operating in SNPN access mode, the AS shall report the available SNPNs to the NAS upon NAS request or autonomously. During this period, the terminal (UE) identifies the list of PLMNs in order of priority; a specific PLMN can also be selected automatically or manually; each PLMN in the PLMN identification list is identified by a “PLMN ID”. Depending on the system information broadcast by the network, a terminal (UE) may receive one or more PLMN IDs in a given cell; the result of the NAS implementation is the identifier of the selected PLMN. Typically at the request of the NAS, the terminal at the access (AS) layer shall search for available PLMNs and report them to the NAS.   Ⅱ.SNPN selection The end equipment (UE) using the private network can automatically or manually select a specific SNPN for its identification list during SNPN selection. each SNPN in the SNPN identification list is identified by an “SNPN ID”. In a system message on a broadcast channel, the UE can receive one or more “SNPN IDs” in a given cell and can choose to receive the associated HRNN. the result of the NAS implementation is the identifier of the selected SNPN.   Ⅲ.PLMN Selection in 5G The 5G terminal (UE) shall scan all RF channels in the supported NR bands for available PLMNs and CAGs according to its capability. on each carrier the terminal (UE) shall search for the strongest cell and read its system information in order to find out to which PLMN the cell belongs and the associated CAGs. for the operation of shared spectrum channel access the terminal (UE) can also read the system information of multiple strongest cells. The terminal (UE) can also read the system information of multiple strongest cells for shared spectrum channel access operations. If the UE can read one or more PLMN identifiers in the strongest cell or multiple strongest cells (in the case of shared spectrum channel access), it shall report each found PLMN as a high-quality PLMN (but without the RSRP value) and any associated CAG-ID to the NAS, provided the following high-quality criteria are met.   * For 5G (NR) cell terminals (UEs) the RSRP measurement shall be greater than or equal to -110 dBm; when PLMNs are found that do not satisfy the high quality criteria, but the UE is able to read their PLMN identifiers, these PLMNs will be reported to the NAS along with their corresponding RSRP values and any associated CAG-ID.The quality measurements that are reported by the UE to the NAS correspond to the quality measurements that are found in a each PLMN found in a cell.   * The terminal (UE) may stop searching for PLMNs based on a request from the NAS, or it may optimize the PLMN search using stored information (e.g., frequency) and optionally cell parameter information from previously received measurement control information elements.   Ⅳ.Once the PLMN has been selected, the terminal (UE) shall perform a cell selection process in order to select the appropriate cell to reside in that PLMN. To support manual CAG selection, the UE shall report to the NAS, upon request, the available CAG IDs and their Manual CAG Selection Allowed Indicator (e.g., broadcast), HRNN (e.g., broadcast), and PLMN.If the NAS has already selected a CAG and provided this selection to the AS, the UE shall search for an acceptable or suitable cell belonging to the selected CAG to be stationed.   Ⅴ.SNPN Selection in 5G At the request of the NAS, the terminal (UE) shall search for available SNPNs in random access (AS) only on NR cells and report them to the NAS. where:The terminal (UE) shall scan all RF channels in the NR band for available SNPNs according to its capability. on each carrier the terminal (UE) shall search for the strongest cell and read its system information to find out which SNPN the cell belongs to. find out which SNPN the cell belongs to. for shared spectrum channel access operation, the UE may also read the system information of multiple strongest cells. If the UE can read one or more SNPN identifiers in the strongest cell, it shall report each SNPN found to the NAS.For manual selection, the UE shall report available SNPN identifiers and their HRNNs (e.g., broadcasts) to the NAS upon the request of the NAS, and may stop the search for available SNPNs upon the request of the NAS. The search for SNPNs may be stopped based on the NAS request. the UE may optimize the SNPN search using stored information (e.g., frequency) and optionally cell parameter information from previously received measurement control information elements. Once the UE has selected an SNPN, a cell selection procedure shall be performed in order to select the appropriate cell for that SNPN to be stationed.

Ⅰ​. RSRP Reference Signal Received Power (RSRP) is a key metric in the 5G wireless communication system, which indicates the power level of the signal received by the terminal (UE) from the wireless cell, and plays a crucial role in determining the quality of the wireless link between the user terminal (UE) and the 5G (UE) base station.5G(NR) RSRP Definition and Measurement in Wireless Networks See:   * RSRP Measurement and Filtering in 5G   * RSRP Measurement Characteristics in 5G(NR)   * RSRP Measurement and Mapping in 5G(NR) Networks   * What is the use of RSRP and RSRQ in 5G?   * RSRP,RSSI,RSRQ and SINR Measurement in 5G   Ⅱ.RSRP and Min RSRP Reference Signal Received Power (RSRP) is measured in dBm (decibels), and the higher the measurement, the stronger the signal. Min RSRP (Minimum Reference Signal Received Power) is defined by the operator as the signal strength that ensures a stable and efficient connection between the user's device and the 5G(NR) network.Min RSRP as a threshold also defines the minimum acceptable strength of the received signal that is required for a reliable connection between the terminal and the network.   Ⅲ.RSRP and Network Coverage RSRP is one of the key metrics when measuring the coverage of a wireless network; typically a higher Min RSRP indicates better network coverage and a stronger, more stable signal. This is particularly important to ensure reliable data transmission and reception, minimize the risk of connection interruptions, and optimize the overall performance of 5G(NR) networks. The specific Min RSRP value in an existing network may vary depending on the network configuration, deployment scenario and service provider. Depending on factors such as population density, urban or rural environments, and the specific use cases they cater to, different regions and operators may have different Min RSRP requirements.   Ⅳ.Min RSRP and User Experience Setting and maintaining Min RSRP levels is critical to ensuring a consistent and high-quality user experience in 5G networks. It helps prevent issues such as signal degradation, dropped connections, and slow data speeds, all of which are important considerations for delivering reliable and efficient 5G services. In addition, a robust RSRP ensures that the 5G network can effectively support applications that require low latency and high data rates, such as augmented reality, virtual reality and critical industrial automation.  

In order to make it easier for the terminal (UE) to understand which cells are available in the network and which ones are not; 3GPP defines in TS38.304 that wireless cells (Cel) in a 5G (NR) network are categorized according to the services they (can) provide as follows;.   I.Acceptable cell is a cell in which a terminal (UE) can reside to obtain limited services (to initiate emergency calls and receive ETWS and CMAS notifications). This type of cell should meet the following requirements (minimum requirements for initiating emergency calls and receiving ETWS and CMAS notifications in 5G networks); the cell is not prohibited; and it meets the cell selection criteria.   * The subdivision is not prohibited. * Meets subdivision selection criteria.   II.Suitable cell for a terminal (UE) not operating in SNPN access mode, a cell is considered suitable if the following conditions are met:   * The cell is part of a list of selected, registered, or equivalent PLMNs and for that PLMN;   * The cell broadcasts a PLMN-ID for that PLMN that has no associated CAG-ID and the CAG unique indication for that PLMN in the UE does not exist or is false;   * The list of allowed CAGs for that PLMN in the UE includes the AG-ID broadcast by the cell for that PLMN;   * The cell selection criteria are satisfied.   According to the latest information provided by NAS:   * The cell is not banned; * The cell belongs to at least one TA that does not belong to the list of "No Tracking Areas", which belongs to the PLMN selection requirements that fulfill the first point above.   For UEs operating in SNPN access mode, a cell is considered suitable if the following conditions are met:   * The cell is part of a UE selected SNPN or registered SNPN;   * The cell selection criteria are met;   According to the latest information provided by NAS:   * The cell is not banned; * The cell belongs to at least one TA that does not belong to the "No Tracking Area" list, which belongs to the selected SNPN or the SNPN registered by the UE.   III.Barred cell If the system information indicates that the cell is barred, the cell is barred.   IV. Reserved cell (reserved cell) If the system information indicates that the cell is reserved, the cell is reserved, except in the following cases;   If the UE is making an emergency call, all acceptable cells of that PLMN are considered suitable for the duration of the emergency call.   On a cell that belongs to a registration area in which the provision of regional services is prohibited; A cell that belongs to a registration area in which the provision of regional services is prohibited is suitable, but only limited services are provided.   The UE may perform NR Sidelink communication or V2X Sidelink communication if the UE in the RRC_IDLE state satisfies the condition of supporting NR Sidelink communication or V2X Sidelink communication in the limited service state.     NOTE: In the RRC CONNECTED state, the UE is not required to support manual search and selection of PLMN or CAG or SNPN, and the UE can use RRC local release.    

Into the 5G (NR) era 3GPP introduced MEC (Multi-access Edge Computing-Multi-access Edge Computing) for mobile communication networks, which is to place the computing resources at the edge of the mobile network; the benefits that can be brought by decentralization of computing power for the 5G system are as follows:   I. Low Latency One of the application benefits in 5G is a significant reduction in latency; by bringing computing resources closer to end users and devices, MEC can minimize the time it takes for data to travel between devices and computing infrastructure. This is critical for applications that require real-time response (e.g., augmented reality, virtual reality, and critical industrial automation processes).   II.High bandwidth efficiency By processing data closer to the source can be more effective use of network bandwidth, without the need to send all the data to a centralized data center, only relevant or processed information transmitted over the network; this not only saves bandwidth, but also improves the overall network efficiency.   III.Expandability The MEC architecture allows for easy scaling of computing resources based on demand, which is especially important in 5G networks; as 5G networks are expected to support a large number of connected devices and a variety of applications, the scalability of MEC ensures that the computing infrastructure can adapt to different workloads and user needs.   IV. Enhanced Security and Privacy MEC enhances security and privacy by processing sensitive data at the edge rather than in a centralized cloud. Critical data can be processed locally, reducing the risk of unauthorized access when data is transmitted over the network. This is particularly beneficial for applications involving sensitive information, such as healthcare and finance.   V. Edge AI Support MEC facilitates the integration of edge artificial intelligence (AI) applications. By running AI algorithms closer to the data source, MEC can speed up the decision-making process. This is critical for applications such as self-driving cars and smart cities that require real-time analysis of data.   VI.User Experience Enhancement The combination of low latency, high bandwidth efficiency, and edge processing improves the overall user experience; applications that require immediate response (e.g., online gaming and video streaming) can benefit greatly from MEC in 5G networks.   MEC applications in 5G offer a range of benefits, including reduced latency, increased bandwidth efficiency, scalability, improved security and privacy, support for edge AI, and enhanced user experience. These benefits make MEC a key component in optimizing 5G network performance across industries and applications.

Regarding MBS data processing, carrier aggregation and discontinuous reception in 5G(NR) networks, 3GPP defines the following in TS38.300;   1. DATA RECEIVING In 5G(NR) the network for multicast service base station side of the gNB can transmit MBS multicast packets using the following methods:   * PTP transmission:The gNB transmits a copy of the MBS packet to each terminal (UE) individually, i.e., the gNB uses the UE-specific PDCCH (CRC is scrambled by the UE-specific RNTI (e.g., C-RNTI)) to schedule the UE-specific PDSCH that is scrambled using the same UE-specific RNTI.   * PTM Transmission:The gNB transmits a single copy of the MBS packet to a group of terminals (UEs), e.g., the gNB uses a group common PDCCH (CRC is scrambled by a group common RNTI) to schedule a group common PDSCH that uses the same group common RNTI scrambling.   2.Terminal (UE) Processing If the UE is configured for both PTM and PTP transmission, the gNB dynamically decides whether or not to transmit multicast data over the PTM line and/or the PTP line for a given UE, based on the defined protocol stack in accordance with the information on the MBS session QoS requirements, the number of UEs joining, the UEs individual feedback on the quality of reception and other criteria. The same QoS requirements apply regardless of the decision made. Among other things:     * UE in RRC_INACTIVE state, MBS multicast session data reception does not support PTP transmission.   * UE in RRC_INACTIVE state, MBS multicast session data reception does not support SPS.   3.Carrier Aggregation (CA) supports 5G terminals (UEs) that can be configured to receive MBS multicast data from a PCell or a single SCell at a time.   4.Discontinuous Reception (DRX) The 5G terminal (UE) performing MBS service can use the following DRX configuration when performing PTM/PTP transmission in RRC_CONNECTED state:     * For PTM transmissions, the multicast DRX is configured according to G-RNTI/G-CS-RNTI, independent of the 5G terminal (UE)-specific DRX;   * For PTP transmissions, the UE-specific DRX will be reused, i.e., the 5G terminal (UE)-specific DRX can be used for both unicast transmissions for MBS multicast and PTP transmissions. For PTM retransmission via PTP, the UE monitors the PDCCH that is scrambled by C-RNTI/CS-RNTI during the specific DRX activity time.    The 5G terminal (UE) of RRC_INACTIVE can use the following DRX configurations when performing PTM transmission:   * For PTM transmissions, multicast DRX is configured per G-RNTI.     ---PTM (Point to Multipoint): Point to Multipoint (Transport)   ---PTP(Point to Point):Point to Point (transmission)    

1. Service continuity :The mobility of the terminal (UE) in 5G-supported multicast service (MBS), in principle, is the same as for other services in 5G (NR) systems.   2.Multicast switching :The mobility procedure for multicast reception allows the UE to continue to receive multicast services via PTM or PTP in the new cell after the switchover; where:   2.1.Switchover preparation phase :The source gNB transmits to the target gNB the UE context information of the MBS multicast sessions to which the UE has joined. in order to support the provision of local multicast services with location-dependent content (as described in TS 23.247 [45]) for each active multicast session, the target gNB may be provided with service area information for each regional session ID. The source gNB may propose data forwarding for certain MRBs to minimize data loss and may exchange the corresponding MRB PDCP sequence numbers with the target gNB during switchover preparation:   If the UE configures a PTP RLC AM entity in the target cell MRB, the MBS supports inter-cell switching and lossless switching of multicast services regardless of whether the UE configures a PTP RLC AM entity in the source cell.   To support lossless switching of multicast services, the network shall ensure synchronization and continuity of the DL PDCP COUNT values between the source and target cells. Additionally PDCP status reports from source gNB to target gNB data forwarding and/or UE for multicast session MRBs may be used during lossless handover.     2.2 Multicast Session Processing : For each multicast session that is performing user data transmission:   If MBS session resources do not exist on the target gNB. the target gNB triggers the setting of MBS user-plane resources to the 5GC using the NGAP distribution setup procedure.   If unicast transmission is used, the target gNB provides the DL tunnel endpoint to be used for MB-SMF.   If multicast transmission is used, the target gNB receives the IP multicast address from the MB-SMF.   2.3 Switchover execution :The MBS configuration decided by the target gNB during the period is sent to the UE via the source gNB within the RRC container (as described in TS38.331 [12]). the PDCP entity of the multicast MRB in the UE may be re-established or may remain as it is. When the UE connects to the target gNB. the target gNB sends an indication to the SMF that it is an MBS Supporting Node in a Path Switching Request message (Xn Switching) or Switching Request Acknowledgement message (NG Switching).   2.4 After Successful Switchover Completion : For any multicast session with no remaining joining UEs in the gNB, the source gNB may trigger the release of MBS user plane resources to the 5GC using the NGAP distribution release procedure.