Infrastructure equipment, circuits and methods for infrastructure equipment

Abstract

To provide wireless communication network systems. [Solution] A method for receiving data associated with a service which is a multicast or broadcast service in a communication device, comprising the steps of: establishing an RRC connection within a cell; receiving the data relating to the service within the cell in a first radio resource control (RRC) mode; determining whether a second predetermined criterion has been met; and, if it has been determined that the second predetermined criterion has been met, sending a point-to-point (PTP) bearer request. The data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of a radio access interface. The PTP bearer request requests parameters for a PTP bearer to receive the data relating to the service.

Description

Technical Field

[0001] The present disclosure relates to communication devices, infrastructure devices, and methods for multicast or broadcast transmission within a wireless communication network. This application claims the Paris Convention priority of European Patent Application No. 20200162.4, the content of which is incorporated herein by reference.

Background Art

[0002] The description of "Background Art" provided herein is for generally presenting the background of the present disclosure. The research of the currently named inventors is not regarded as prior art for the present invention either explicitly or implicitly, in the same way as aspects of the specification that are not regarded as prior art at the time of filing as long as they are described in this background art section.

[0003] Third-generation and fourth-generation mobile communication systems, such as those based on the 3GPP-defined UMTS and LTE (Long Term Evolution) architectures, can support services more advanced than the simple voice and messaging services provided by previous-generation mobile communication systems. For example, using the improved wireless interface and extended data rates provided by the LTE system, users can enjoy high-data-rate applications such as mobile video streaming and mobile video conferencing, which were previously only available via fixed-line data connections. Therefore, the demand for deploying such networks is strong, and the coverage areas of these networks, i.e., the geographical locations where access to the network is possible, are expected to expand more and more rapidly.

[0004] Future wireless communication networks are expected to routinely and efficiently support communication with a wider range of devices, related to a broader range of data traffic profiles and types, rather than being optimized to support current systems. For example, future wireless communication networks are expected to efficiently support communication with devices including devices with reduced complexity, machine-type communication (MTC) devices, high-resolution video displays, and virtual reality headsets. Some of these different types of devices may be deployed in a very large number of low-complexity devices to support, for example, the "Internet of Things," and may typically be associated with the transmission of relatively small amounts of data with relatively high latency tolerance.

[0005] From this perspective, it is expected that future wireless communication networks, such as 5G or new radio (NR) systems / new radio access technology (RAT) systems (Non-Patent Literature 1), and what may be called future versions / releases of existing systems, will efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles.

[0006] While most traditional services are delivered via unicast data transmission, many services are better suited to multicast or broadcast transmission. The provision of such services presents new challenges for efficiently handling communications in wireless telecommunications systems that require such attention. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] 3GPP TS 38.300 v. 15.2.0, "NR; NR and NG-RAN Overall Description; Stage 2(Release 15)", June 2018. [Non-Patent Document 2] Holma H. ​​and Toskala A, "LTE for UMTS OFDMA and SC-FDMA based radio access", John Wiley and Sons, 2009. [Non-Patent Document 3] 3GPP TS 38.331, "NR; Radio Resource Control (RRC); Protocol specification", version 16.1.0, July 2020. [Non-Patent Document 4] 3GPP Tdoc R2-2006794, "NR Multicast dynamic PTM PTP switch with service continuity", 3GPP TSG-RAN WG2 Meeting #11 le, August 2020, Qualcomm Inc. [Non-Patent Document 5] 3GPP Tdoc R2-2007631, "Protocol structure and bearer modeling for NR MBS", 3GPP TSG-RAN WG2 Meeting #11 le, August 2020, Ericsson. [Overview of the project]

[0008] This disclosure may help address or mitigate at least some of the problems described above.

[0009] Each aspect and feature of this disclosure is defined in the appended claims.

[0010] It should be understood that both the general description above and the detailed description below are illustrative of the technology, but not limiting. The embodiments described, along with further advantages, are best understood by referring to the detailed description below in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0011] Since the same reference numerals indicate the same or corresponding parts in several figures, the detailed description below, in conjunction with the accompanying drawings, will be better understood by referring to the detailed description below. [Figure 1] This schematically represents several embodiments of an LTE-type wireless telecommunications system configured to operate according to specific embodiments of the present disclosure. [Figure 2] This schematically illustrates several exemplary embodiments of a novel radio access technology (RAT) radio telecommunications system configured to operate according to specific embodiments of the present disclosure. [Figure 3] This is a schematic block diagram of an example of infrastructure equipment and communication devices configured according to an exemplary embodiment. [Figure 4] This shows the process of a communication device that detects wireless link failures using conventional technology. [Figure 5] This is a sequence chart and process diagram of a composite message for receiving multicast / broadcast service (MBS) data after a wireless link failure, according to an embodiment of this technology. [Figure 6] This is a sequence chart and process diagram of a composite message for receiving multicast / broadcast service (MBS) data after a wireless link failure, according to an embodiment of this technology. [Figure 7] This is a composite message sequence chart and process diagram for receiving MBS data according to an embodiment of this technology. [Figure 8]This is a process flow diagram of a process that can be executed by a communication device according to an embodiment of this technology. [Modes for carrying out the invention]

[0012] (Long Term Evolution Advanced Radio Access Technology (4G)) Figure 1 provides a schematic diagram illustrating some basic functions of a mobile telecommunications network / system 100, which generally operates according to LTE principles but can also support other radio access technologies and can be adapted to implement embodiments of the disclosure as described herein. The various elements in Figure 1 and specific aspects of their respective operating modes are well known and defined in the relevant standards managed by the 3GPP(RTM) organization, and are also described in numerous books on the subject, such as Non-Patent Literature 2 by Holma H. ​​and Toskala A. It is understood that any mode of operation of telecommunications networks not specifically described herein (for example, with respect to specific communication protocols and physical channels for communication between different elements) may be implemented in accordance with any known techniques, for example, in accordance with the relevant standards and known proposed modifications and additions to those standards.

[0013] The network 100 includes a plurality of base stations 101 connected to the core network section 102. Each base station provides a coverage area 103 (e.g., a cell) that can communicate data with a communication device 104. Data is transmitted from the base station 101 to the communication device 104 within its respective coverage area 103 via a wireless downlink. Data is transmitted from the communication device 104 to the base station 101 via a wireless uplink. The core network unit 102 communicates with the communication device 104 via each base station 101 and provides functions such as authentication, mobility management, and charging. A communication device may also be called a mobile station, user equipment (UE), user terminal, mobile radio, terminal device, etc. A base station, which is an example of a network infrastructure device / network access node, may also be called a transceiver station / node B / eNode B, gNode B (gNB), etc. In this regard, different terms are often associated with different generations of radio communication systems for elements that provide broadly equivalent functionality. However, the exemplary embodiments of the present disclosure may be equally implemented in different generations of radio communication systems such as 5G or new radio described below, and for the sake of brevity, specific terms may be used regardless of the underlying network architecture. That is, the use of specific terms related to specific embodiments is not intended to indicate that these embodiments are limited to a specific generation of network to which those specific terms are most likely to be related.

[0014] (New Radio Access Technology (5G)) FIG. 2 is a schematic diagram showing a network architecture for a New RAT wireless communication network / system 200 based on a previously proposed approach that may also be adapted to provide the functions according to the embodiments of the present disclosure described herein. The New RAT network 200 shown in FIG. 2 includes a first communication cell 201 and a second communication cell 202. Each communication cell 201, 202 includes control nodes (centralized units) 221, 222 that communicate with the core network component 210 via respective wired or wireless links 251, 252. In addition, each control node 221, 222 also communicates with a plurality of distributed units (radio access nodes / remote transmit-receive points (TRPs)) 211, 212 within each cell. Also in this case, these communications can be performed via respective wired or wireless links. The distributed units 211, 212 serve to provide a wireless access interface to a communication device connected to the network. Each distributed unit 211, 212 has a coverage area (wireless access footprint) 241, 242, and the sum of the coverage areas 241, 242 of the distributed units 211, 212 under the control of the control nodes 221, 222 together defines the coverage of the respective communication cells 201, 202. Each distributed unit 211, 212 includes a transmitter circuit (receiver circuit) for transmitting and receiving wireless signals, and a processor circuit (controller circuit) configured to control each distributed unit 211, 212.

[0015] From a broad top-level functionality perspective, the core network part 210 of the New RAT communication network represented in FIG. 2 can be broadly considered to correspond to the core network 12 represented in FIG. 1. Each control node 221, 222 and their associated distributed units / TRPs 211, 212 can be broadly considered to provide functionality corresponding to the base station 11 in FIG. 1. The term network infrastructure device / access node may be used to encompass these components and the more conventional base station-type components of a wireless communication system. Depending on the application at hand, the obligation to schedule transmissions scheduled on the wireless interface between each distributed unit and the communication device may lie with the control node / concentrator unit, and / or the distributed unit / TRP.

[0016] Figure 2 shows a communication device, namely UE260, located within the coverage area of ​​the first communication cell 201. Thus, this communication device 260 can exchange signals with the first control node 221 within the first communication cell via one of the distributed units 211 associated with the first communication cell 201. In some cases, communication from a given communication device is routed through only one of the distributed units, but in some other implementations, it is understood that communication related to a given communication device may be routed through two or more distributed units, for example in the case of a soft handover (scenario) and in other cases.

[0017] For simplicity, the example in Figure 2 shows two communication cells 201 and 202 and one communication device 260, but it should be understood that in reality, the system can have many more communication cells (supported by their respective control nodes and multiple distributed units) serving a much larger number of communication devices.

[0018] Figure 2 shows just one example of an architecture proposed for a New RAT communication system in which the principle-based approach described herein may be employed, and it will be further understood that the functions disclosed herein may also be applicable to wireless communication systems having different architectures.

[0019] Accordingly, exemplary embodiments of the disclosure described herein may be implemented in wireless telecommunications systems / networks with various different architectures, such as the exemplary architectures shown in Figures 1 and 2. Therefore, it should be understood that a particular wireless communication architecture in any given implementation is of no primary importance to the principles described herein. In this regard, exemplary embodiments of this disclosure can generally be described in terms of communication conditions between network infrastructure equipment / access nodes and communication devices, and the specific nature of the network infrastructure equipment / access nodes and communication devices will depend on the network infrastructure for the present implementation. For example, in some cases the network infrastructure equipment / access node may include a base station such as the LTE-type base station 11 shown in Figure 1, which is adapted to provide functionality according to the principles described herein, and in other examples the network infrastructure equipment / access node may include control / control nodes 221, 222 and / or TRPs 211, 212 of the type shown in Figure 2, which are adapted to provide functionality according to the principles described herein.

[0020] A more detailed description of the communication device 270 and an exemplary network infrastructure device 272, which can be a combination of the gNB 101 or the control node 221 and the TRP 211, is shown in Figure 3. As shown in Figure 3, the communication device 270 is configured to transmit uplink data to the infrastructure equipment 272 of the wireless access interface, as generally indicated by arrow 274. UE 270 is shown to receive downlink data transmitted by infrastructure equipment 272 via the resources of the radio access interface, as generally indicated by arrow 288. Similar to Figures 1 and 2, infrastructure equipment 272 is connected to core network 276 (which may correspond to core network 102 in Figure 1 or core network 210 in Figure 2) via interface 278 to the controller 280 of infrastructure equipment 272. The infrastructure device 272 may also be connected to other similar infrastructure devices by a radio-to-radio access network node interface, as is not shown in Figure 3.

[0021] Infrastructure equipment 272 includes a receiver 282 connected to antenna 284 and a transmitter 286 connected to antenna 284. Correspondingly, communication device 270 includes a controller 290 connected to a receiver 292 that receives signals from antenna 294 and a transmitter 296 similarly connected to antenna 294.

[0022] The controller 280 is configured to control the infrastructure equipment 272 and may include a processor circuit (controller circuit) that sequentially comprises various subunits / subcircuits for providing desired functions, as further described herein. These subunits can be implemented as individual hardware elements or as appropriately configured functions within a processor circuit. Therefore, the controller 280 can be composed of circuits appropriately configured / programmed to provide the desired functionality described herein, using conventional programming / configuration techniques for equipment in wireless telecommunications systems. The transmitter 286 and receiver 282 may include conventional signal processing, radio frequency filters, amplifiers, and circuits. The transmitter 286, receiver 282, and controller 280 are schematically shown in Figure 3 as separate elements for ease of representation. However, it is understood that the functionality of these circuit elements can be provided in various different ways, for example, using one or more appropriately programmable computers, or one or more appropriately configured application-specific integrated circuits / circuits / chips / chipsets. It is understood that infrastructure equipment 272 may generally have various other elements related to its operational functions.

[0023] Accordingly, the controller 290 of the communication device 270 may include a processor circuit (controller circuit) configured to control the transmitter 296 and the receiver 292, and comprising various subunits / subcircuits in sequence for providing functions as further described herein. These subunits may be implemented as individual hardware elements or as functions appropriately configured in the processor circuit. Therefore, the controller 290 may include circuits that are appropriately configured / programmed to provide desired functionality using conventional programming / configuration techniques for equipment in wireless telecommunications systems. Similarly, the transmitter 296 and receiver 292 may include conventional signal processing, radio frequency filters, amplifiers, and circuits. The transmitter 296, receiver 292, and controller 290 are schematically shown in Figure 3 as separate elements for ease of representation. However, it is understood that the functionality of these circuit elements may be provided in a variety of different ways, for example, using one or more appropriately programmable computers, or one or more appropriately configured application-specific integrated circuits / circuits / chips / chipsets. As can be understood, the communication device 270 generally includes various other elements related to its operational functions, such as a power supply and a user interface, but these are not shown in Figure 3 for the sake of brevity.

[0024] Controllers 280 and 290 may be configured to execute instructions stored in a computer-readable medium such as non-volatile memory. The processing steps described herein may be performed by a microprocessor together with random-access memory, which may be non-volatile memory, that operates according to instructions stored in a computer-readable medium.

[0025] (Wireless Bearer) Transmission between communication devices and infrastructure equipment may involve a wireless bearer. A wireless bearer may be a logical connection, which may be associated with one or more logical channels and one or more corresponding transport channels. A bidirectional wireless bearer can be associated with a pair of logical channels (one for each uplink and downlink) and a pair of transport channels (one for each uplink and downlink).

[0026] For example, a data radio bearer (DRB) for transmitting user plane data may be associated with two dedicated traffic channels (DTCHs) for transmitting uplink and downlink user data, respectively, associated with a single communication device. One DTCH may be associated with a downlink (DL) shared channel (DL-SCH), and the other DTCH may be associated with an uplink (UL) shared channel (UL-SCH).

[0027] As before, a signaling radio bearer (SRB) can be provided to transmit signal messages between the communication device 270 and the infrastructure equipment 272. In particular, the following SRBs may be defined (Non-Patent Literature 7): - SRB0 for RRC messages using the Common Control Channel (CCCH) logical channel; - SRB1 for RRC messages (which may include piggybacked NAS messages) and NAS messages before SRB2 is established (all using a dedicated control channel (DCCH) logical channel); - SRB2 for NAS messages, using all DCCH logical channels. SRB2 has a lower priority than SRB 1 and is always set by the network after security is enabled.

[0028] The RRC connection mode corresponds to a mode in which a communication device establishes an RRC connection with infrastructure equipment. Data can be transmitted to and from the communication device, for example, by authorized resources on a shared channel. In RRC connection mode, changes in the serving cell of the communication device are under the control of the network and can be performed, for example, by handover.

[0029] The RRC idle mode corresponds to a mode in which an RRC connection has not been established. The communication device can transition from RRC idle mode to RRC connected mode as usual, for example, by a random access procedure, and establish an RRC connection. In RRC idle mode, the communication device may autonomously change the serving cell, for example, by a cell reselection procedure.

[0030] (Wireless link failure and re-establishment of connection) The quality of the radio link associated with a serving cell (e.g., cell 103) can be periodically evaluated, for example, once at each predefined duration. The radio link quality of a cell can be determined based on measurements of the signal transmitted to a given resource, which can be associated with the activated bandwidth portion (BWP). A predetermined threshold can be used in conjunction with the evaluated wireless link quality to determine whether or not a wireless link failure has occurred in a given cell.

[0031] RRC re-establishment may be triggered by a communication device, such as communication device 270, in response to the detection of a radio link failure (RLF) when the RRC connection mode is active and there is an RRC connection with security activated. A radio link failure may be determined to have occurred (i.e., detected) if the radio link measurement of infrastructure equipment 272 meets one or more predetermined radio link failure criteria.

[0032] When a communication device is in RRC connection mode and a wireless link failure is detected, the communication device, at the time of the wireless link failure, - At least one data radio bearer (DRB) is established, - A signaling radio bearer for transmitting non-accessible stratum (NAS) messages, such as an SRB2 bearer, is established, - Access Stratum (AS) security has been activated. Only in this case can we attempt to re-establish the connection as before (Non-Patent Document 3).

[0033] If one or more of these conditions are not met, re-establishment will not be performed, and the communication device will enter RRC idle mode.

[0034] Figure 4 shows the process of a communication device that detects wireless link failures using conventional technology.

[0035] This process begins in step S402, where the communication device enters RRC connection mode within the cell. In step S404, the communication device performs radio link monitoring. As part of the radio link monitoring, measurements can be taken to determine whether radio link fault criteria are met. The measurements may include radio link measurements.

[0036] In step S406, the communication device determines whether the criteria for a radio link failure are met. These may be based on radio link monitoring and / or other criteria. An RLF may be determined to have occurred in response to a failure in the mobility procedure, a failure in the integrity of SRB1 or SRB2, or a failure in the RRC reconfiguration procedure.

[0037] If this criterion is not met ("No"), the process returns to step S404.

[0038] Steps S404 and S406 can be performed periodically.

[0039] If the criteria are met in step S406, control moves to step S408, where a radio link failure (RLF) is declared. In step S408, the RLF may be notified to the higher protocol layer. In step S408, the communication device 208 may suspend all radio bearers except SRB0.

[0040] Next, in step S410, the communication device can perform a cell selection procedure according to conventional technology to select an appropriate cell.

[0041] In step S412, the communication device determines whether access layer (AS) security was activated in RRC connection mode (i.e., before step S408). If not, control proceeds to step S420, the communication device enters RRC idle mode, and processing ends.

[0042] If AS security is activated (yes in step S412), control moves to step S414.

[0043] In step S414, it is determined whether the communication device is a signal radio bearer established specifically for transmitting encapsulated NAS messages and is an SRB2 established prior to step S408. Otherwise, control proceeds to step S420.

[0044] If a signal radio bearer is established (yes in step S414), control is passed to step S416.

[0045] In step S416, the communication device determines whether one or more data radio bearers established for the transmission of higher layer data were established prior to step S408. If not, control proceeds to step S420.

[0046] If a data radio bearer is established (yes in step S416), control proceeds to step S418.

[0047] In step S418, the communication device initiates RRC re-establishment. This can be done by initiating a random access procedure on a selected cell (the cell where the RLF was determined, or a different cell) to obtain an uplink resource allocation. The communication device may then use the allocated uplink resource on CCCH / SRB0 to send an RRC re-establishment request message to the infrastructure equipment (e.g., gNB) of the new cell.

[0048] If the gNB controlling the selected cell has or can obtain a memory context for the communication device and therefore can verify the contents of the RRC re-establishment request, upon receiving the RRC re-establishment request message, the gNB will send an RRC re-establishment message providing parameters to enable the communication device to re-establish the RRC connection within the selected cell.

[0049] Following step S420, the communication device can begin establishing a new RRC connection within the selected cell. This allows the communication device to establish an RRC connection and enter RRC connection mode when the providing infrastructure equipment in the selected cell does not have (or does not have access to) the context of an RRC connection established before the radio link failure.

[0050] (Multicast / Broadcast Service (MBS)) Many services provided to wireless communication devices are unicast services. In unicast services, only a single communication device receives the service. Examples include voice calls, data transfer, and point-to-point messaging services.

[0051] Multicast and broadcast services (MBS) allow multiple devices to receive the same service simultaneously. An example of a multicast service is a group voice call, where the same voice content is received simultaneously by multiple communication devices within a specific group. An example of a broadcast service is a streaming service, such as audio or video broadcasting, which can be received and decoded simultaneously by all compatible communication devices within a specific coverage area.

[0052] Receiving (or providing) a service in this context may include the use of uplink transmission, downlink transmission, or both. In some examples, the provision of an MBS may be related to feedback and / or measurement reporting, for example, and may be required to transmit information in the uplink, although it may be done exclusively by downlink transmission.

[0053] In this specification, the terms unicast, broadcast, and multicast are used in the context of a specific wireless communication network or a part thereof (such as a single cell). Therefore, for example, if a single user within a cell accesses a streaming service from a third-party server located outside the wireless communication network, this may be considered a unicast service (for the current purposes), even if the third-party server allows simultaneous access to multiple devices (even within the same cell) through multiple connections, each of which are unicast connections from the perspective of the wireless communication network. Accordingly, the terms multicast and broadcast as used herein may also be related to the core network of a radio access network and / or radio communication network that enables two or more devices to receive a service simultaneously. For example, if the core network provides multicast functionality and enables multiple communication devices within each cell to receive a single service simultaneously, then transmissions to each communication device within each cell, even if they are unicast transmissions (within the range of that cell), fall within the scope of this disclosure.

[0054] Therefore, multicast / broadcast services can efficiently provide the same service to multiple users within a wireless communication network by using fewer communication resources (on the wireless access network and / or on internal connections within the wireless communication network) than would be required to provide the same service to multiple users via unicast connections.

[0055] MBS data can be transmitted using a radio bearer. The bearer used to transmit MBS data is called an MBS radio bearer (MRB). A point-to-point (PTP) MRB may be a DRB or a different type of radio bearer than a DRB. If the MBS data is multicast within a cell using point-to-multipoint (PTM) transmission, the MRB may be associated with a transport channel of a type for multicast transmission within the cell. For example, the transport channel may be a multicast broadcast traffic channel (MBTCH), and the associated physical channel may be a DL-SCH.

[0056] Specific proposals for mapping bearers that carry MBS data to logical and physical channels are specified in Non-Patent Documents 4 and 5, the contents of which are incorporated herein by reference.

[0057] Certain proposals (e.g., Non-Patent Document 4) assume that common security parameters apply to PTP and PTM bearers of an MBS service given. That is, a common security key setting is used for both PTP and PTM bearers used for the same MBS service, but different from the key setting used for the UE's unicast session. Other proposals (e.g., Non-Patent Document 5) assume that MBS data uses conventional DRB when transmitted via unicast.

[0058] Another proposal suggests that while no security is applied to transmissions via the PTM bearer, the communication device receives the MBS bearer in RRC connection mode.

[0059] The communication device may be in RRC mode, which enables reception of MBS services. In particular, the communication device may receive MBS services via MRB while in RRC connection mode.

[0060] However, it is necessary to ensure that communication devices can continue to receive MBS services even if the wireless link quality deteriorates.

[0061] Embodiments of this technology can provide a method for a communication device to receive data associated with a service that is a multicast or broadcast service. This method is Steps to establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, In the first RRC mode described above, the steps include measuring the radio link quality associated with the radio access interface, Based on the above wireless link quality, a step is to determine whether a predetermined standard has been met, After determining that the above-mentioned criteria have been met, the step of receiving further data related to the above-mentioned service, Includes, The above data is transmitted using the communication resources of the above wireless access interface. The above-mentioned predetermined criteria are the criteria for continuing to receive the above-mentioned data related to the above-mentioned service in the above-mentioned first RRC mode within the above-mentioned cell.

[0062] Embodiments of this technology can enable a communication device to continue receiving data related to MBS services. In particular, if the communication device enters an RRC mode in which re-establishment is generally permitted (e.g., RRC connection mode), the communication device may re-establish itself and, after re-establishment, continue receiving MBS data.

[0063] A communication device may receive MBS data in RRC connection mode without establishing a specific type of radio bearer. For example, if neither DRB nor SRB2 is established, the communication device may receive MBS data in RRC connection mode. Embodiments of this technology enable the communication device to re-establish itself in such circumstances and thus continue to receive MBS services. Re-establishment may be initiated, for example, in response to a determination of a radio link failure.

[0064] This embodiment can reduce interruption time and allow a communication device to continue receiving MBS data related to a service, even when the only service currently available to the communication device is an MBS service. If the only service currently available to the communication device is an MBS service, the communication device does not need to be configured to include bearers and / or bandwidth portions for transmitting data unrelated to the MBS service.

[0065] In some embodiments, the re-establishment may be that of a wireless bearer used for transmitting MBS data, thus minimizing, signaling, and reducing delays associated with interruptions in MBS data reception.

[0066] In some embodiments of this technology, the communication device performs a re-establishment regardless of the establishment of the DRB and / or SRB2 when in RRC connection mode. In some such embodiments, resources for a bearer to receive MBS data are configured as part of the re-establishment procedure. In some embodiments, resources for a bearer to receive MBS data are configured after the re-establishment procedure.

[0067] Figure 5 shows a sequence chart and process diagram of a composite message for re-establishing a connection according to an embodiment of this technology.

[0068] In Figure 5 and similar figures, time progresses from top to bottom, but without scaling.

[0069] In step S502, the communication device 270 enters RRC connection mode in the first cell controlled by the infrastructure equipment 272. This includes establishing an RRC connection and activating AS security.

[0070] In step S504, the communication device 270 establishes a bearer (referred to here as an MBS radio bearer, or MRB) for the purpose of receiving MBS data within the cell.

[0071] In one embodiment, the MRB may already be established within the cell, and in step S504, the communication device may obtain permission to receive data through the already established MRB and may obtain parameters (such as security parameters, communication resources, and / or transmission parameters) for receiving MBS data through the MRB.

[0072] The MRB may be a point-to-multipoint (PTM) bearer or a point-to-point (PTP) bearer. The MRB may be associated with security parameters common to one or more other MRBs (such as an encryption key or its precursor). The other MRBs may be PTP or PTM MRBs and may be configured in the same cell or a different cell as the cell in which the communication device 270 performs step S504.

[0073] The MRB used before a wireless link failure is called the "first MRB."

[0074] In some embodiments, the communication device 270 does not need to establish one or more of the DRB and / or SRB2 within the cell.

[0075] Next, in step S506, the communication device 270 receives MBS data 552 from the infrastructure equipment 270 via the MRB.

[0076] In step S508, the communication device 270 determines that the criteria for a radio link failure are met. In response to this determination, the communication device exits RRC connection mode as indicated by arrow 564. At this point, the communication device 270 may consist of one or more MRBs for the purpose of receiving MBS data. The communication device 270 may not consist of a DRB or an SRB2, or it may consist of only one of a DRB and an SRB2. The communication device 270 may consist of an SRB1, and the SRB1 may be used for transmitting any NAS signal.

[0077] Each MRB may be associated with a corresponding identifier, such as a Group Radio Network Temporary Identifier (G-RNTI).

[0078] In one embodiment of the present technology, the communication device 270 decides to proceed with a re-establishment procedure. This decision may be made regardless of whether a DRB (transmission and reception of data not associated with MBS services) is established in the cell when step S508 is performed, and / or whether an SRB2 is established in the cell when step S508 is performed. In one embodiment, if the communication device 270 was configured to receive MBS data via the MRB when a radio link failure criterion is met, it decides to proceed with a re-establishment procedure.

[0079] As described above, in the example in Figure 5, a determination is made to re-establish the connection regardless of the setup method for the DRB or the SRB. In some embodiments, the determination may be conditional on the AS security being activated, and SRB2 and at least one DRB are set up.

[0080] In step S510, the communication device 270 performs cell selection that can follow conventional technology.

[0081] In some embodiments, cell selection includes selecting a candidate cell as a new cell only if the system information includes, for example, information that enables the communication device 270 to receive MBS data in the candidate cell by a PTM bearer. The information within the candidate cell system information may include PTM bearer configuration information. Cell selection may be autonomous or network-assisted. For example, network-assisted cell selection may include receiving instructions from infrastructure equipment 272 for candidate cells to be selected within the current cell.

[0082] In some embodiments, cell selection may include selecting a cell as a new cell if a configuration valid within the current cell (i.e., the configuration in which a radio link failure was detected) is also valid within that cell.

[0083] In the example in Figure 5, the communication device 270 selects a cell controlled by infrastructure equipment 272 in step S510, but it is understood that the infrastructure equipment controlling the selected cell may be a different infrastructure equipment. The selected cell may be the same cell from which the MBS data 552 was received.

[0084] In step S512, the communication device 270 sends a re-establishment request 554 to the infrastructure equipment 272. The re-establishment request 554 may include an MRB re-establishment request (MRR) 562 indicating that the communication device 270 is requesting the re-establishment of the MRB used to receive the MBS data 552, or is seeking to regain access to that MRB.

[0085] In step S514, the infrastructure equipment sends a re-establishment response 556 in response to the re-establishment request 554. In some embodiments, where the MRR 562 is sent as part of the re-establishment request 554, the re-establishment response 556 may include MRB parameters 558.

[0086] In some embodiments, MRR 562 may be transmitted after the re-establishment procedure and after the communication device 270 has entered RRC connection mode.

[0087] In some embodiments (including embodiments in which MRR 562 is sent after re-establishment), the MRB parameter 558 may be sent separately from the re-establishment response 556, for example, after the communication device 270 has completed the re-establishment procedure and entered RRC connection mode.

[0088] The MRB parameter 558 may provide parameters necessary for the communication device 270 to receive further MBS data via the MRB in the selected cell ("second MRB"). If the selected cell is the same as the first cell, the first MRB may be the same as the second MRB. However, even if the selected cell and the first cell are the same, the second MRB may be different from the first MRB.

[0089] The first MRB and the second MRB are either both PTM bearers, both PTP bearers, or one PTM bearer and one PTP bearer. The first MRB and the second MRB may share parameters such as security keys and / or parameters defining the resources on which their respective MBS data are transmitted.

[0090] After receiving the re-establishment response 556, the communication device 270 may transition to RRC connection mode, as indicated by arrow 566.

[0091] In step S516, the communication device 270 receives further MBS data 560 via the second MRB.

[0092] Therefore, embodiments of this technology can ensure that the communication device 270 can receive MBS data after the quality of the wireless link within the cell has deteriorated.

[0093] In the example in Figure 5, after a wireless link failure, the communication device enters RRC connection mode through a re-establishment procedure and continues to receive MBS data 560 while in RRC connection mode (as indicated by arrow 566).

[0094] In one embodiment, the MBS data 560 is received while the communication device is in RRC idle mode or RRC inactive mode. In one embodiment, for example, the communication device may be in RRC connected mode in a first cell and receive MBS data via a first MRB (which may be a PTP or PTM bearer), and in response to determining that a radio link failure has occurred in the first cell, it selects a second cell and receives further MBS data via a second PTM MRB in RRC mode.

[0095] Figure 6 shows a composite message sequence chart and process diagram for receiving MBS data after a wireless link failure, according to an embodiment of this technology.

[0096] Many of the steps and elements shown in Figure 6 are the same as those in Figure 5. They are given the same reference numbers, and their explanations are omitted for brevity.

[0097] Unlike the example shown in Figure 5, in the example in Figure 6, the communication device 270 does not initiate a re-establishment procedure in response to the wireless link failure detected in step S508.

[0098] In one embodiment, the communication device 270 may determine whether or not to re-establish the wireless link in response to a wireless link failure in step S508. In one embodiment, this may be according to conventional conditions for re-establishment, in particular, - AS security is activated, and, - If SRB2 and at least one DRB are not set up, The communication device 270 decides not to re-establish the connection and to transition to RRC idle mode, as shown in the example in Figure 6.

[0099] If the conditions for re-establishment are met, the communication device 270 can initiate re-establishment and proceed as shown in the example in Figure 5.

[0100] The communication device 270 may perform cell selection in step S510.

[0101] Next, the communication device 270 remains in RRC idle mode (as indicated by arrow 666) and receives MBS data 560 during RRC idle mode.

[0102] The MBS data 560 may be transmitted using PTP or PTM MRB. This MRB may be the same MRB used to receive the MBS data 552 in RRC connection mode. Thus, the communication device 270 may receive the MBS data 560 by using the same parameters used in RRC connection mode to receive the MBS data 552.

[0103] In one embodiment, the communication device 270 may receive an inactive mode configuration from the infrastructure equipment 272 before determining that a radio link failure has occurred while in RRC connection mode. This inactive mode configuration may include parameters indicating that the communication device 270 is permitted to enter RRC inactive mode after exiting RRC connection mode. In RRC inactive mode, the RRC connection between the communication device 270 and the infrastructure equipment 272 is not active, but the infrastructure equipment 272 and the communication device 270 maintain their respective contexts, reducing the time required to subsequently enter RRC connected mode, which allows the RRC connection to be established thereafter.

[0104] In some embodiments, the inactive mode configuration may be transmitted within the RRC reconfiguration message.

[0105] In some embodiments, the communication device 270 can decide whether to enter RRC inactive mode or RRC idle mode based on whether it has received an inactive mode configuration in response to a determination that a radio link failure has occurred.

[0106] Therefore, when the communication device 270 receives an inactive mode configuration and detects a radio link failure, it enters RRC inactive mode and can continue to receive MBS data while in RRC inactive mode. Such an embodiment is substantially similar to the example in Figure 6, except that the communication device 270 receives an inactive mode configuration (not shown in Figure 6) and the MBS data 560 is received in RRC inactive mode rather than RRC idle mode.

[0107] In some embodiments, MBS data 552 may be received via a PTM MRB. However, if a radio link failure occurs or re-establishment is required, the PTM MRB may not be immediately re-establishable. On the other hand, the PTP MRB may be re-establishable (for example, if the PTP MRB is a DRB).

[0108] Embodiments of this technology can provide a method by which a communication device 270 requests the provision of MBS services via a PTP bearer such as a DRB as a response to determining that predetermined criteria have been met.

[0109] In some embodiments, when receiving MBS data via a PTM bearer, the network may receive limited or no feedback from the communication device regarding link quality, measurement reports, data acknowledgments, etc. In fact, the communication device may receive MBS data without any infrastructure equipment associated with the current cell (for example, because the network does not require the communication device to perform uplink signals when receiving MBS data via a PTM bearer). In particular, infrastructure equipment does not need to be aware of deteriorations in the wireless conditions applied to the MBS data that communication devices are receiving.

[0110] In one embodiment, when MBS data is received via a PTP bearer, certain feedback is provided to the network. The nature of this feedback may depend on the RRC mode of the communication device and / or whether the PTP bearer is DRB. In any case, the network (e.g., infrastructure equipment) may have more information related to the communication device and its ongoing reception of MBS data than when the data is received via a PTP bearer. Therefore, re-establishment may only be possible if data is received via a PTP bearer.

[0111] Embodiments of this technology can subsequently ensure that criteria related to wireless link failure are met, that communication devices can perform a re-establishment procedure, and that following the re-establishment procedure, MBS data can be received, for example, via a PTP bearer.

[0112] Figure 7 shows a composite message sequence chart and process diagram for receiving MBS data after a wireless link failure, according to an embodiment of this technology.

[0113] Many of the steps and elements shown in Figure 7 are identical to those in Figure 5. They share the same reference numbers, and for brevity, their explanations are omitted.

[0114] In the example shown in Figure 7, according to several embodiments, the MBS data 552 is received in step S506 via a point-to-multipoint bearer 774. While such a bearer allows multiple communication devices in a cell to receive the MBS data 552 while efficiently utilizing communication resources, it can be more complex and / or slow for communication devices to continue receiving further MBS data via a PTM bearer after a radio link failure.

[0115] In step S707a, the communication device 270 determines that certain predetermined conditions are met. These may be based on measurements of the radio link within the cell. The measurements may be the same as, or a subset of, those used to determine whether a radio link failure has occurred. The predetermined conditions may be met before the conditions for a radio link failure are met, in the event that the radio link degrades (e.g., the rate of bit or block errors increases, and / or path loss and / or interference increases).

[0116] In step S707b, in response to the determination that a predetermined condition was met in step S707a, the communication device 270 sends a PTP bearer request 768 to the infrastructure equipment 272. The PTP bearer request 768 indicates that the communication device 270 is requesting the reception of MBS data via a point-to-point (PTP) bearer. The PTP bearer request 768 may include an indication of the identity (identifier) ​​of the MBS service (e.g., a temporary multicast / broadcast group identifier, TMGI) and / or the identity of the PTM MBR 774 from which the MBS data 552 will be received (e.g., a temporary wireless network identifier, RNTI).

[0117] In step S707c, the infrastructure device 272 sends a PTP bearer response 770 to the communication device 270. The PTP bearer response 770 may include instructions for parameters related to the PTP bearer 776 on which the MBS data may be received. The parameters may include security parameters, transmission parameters, and / or parameters characterizing the communication resources used by the PTP bearer. The PTP bearer 776 may be a conventional DRB.

[0118] In step S707d, infrastructure equipment 272 transmits MBS data 772 via PTP bearer 776, and communication device 270 receives it.

[0119] Next, in step S508, the communication device 270 determines that the conditions for a wireless link failure have been met. At this point, as shown in the example in Figure 5, the communication device 270 may determine that SRB2 has not been established and / or DRB has not been established (for example, PTP MRB 776 is not the DRB).

[0120] Steps S510, S512, S514, and S516 may proceed as shown in the example in Figure 5. In some embodiments, for example, if the PTP MRB 776 is a DRB, the MRR 562 and MRB parameter 558 may be omitted from the re-establishment request 554 and re-establishment response 556, respectively.

[0121] The MBS data 560 received in step S516 may be transmitted via the PTP MRB 776 that has been re-established as a result of the re-establishment procedure.

[0122] In some embodiments, the MBS data 552 is received in step S506 via a point-to-point (PTP) MBS bearer, and the PTP MBS bearer is not via a DRB (non-DRB) rather than via a PTM bearer 774, as in the example in Figure 7. A non-DRB PTP MBS bearer may offer certain advantages for receiving the MBS data 552 compared to a conventional DRB. For example, if only a PTP MRB is established and maintained, the specific procedures required for establishing and / or maintaining a DRB may not be necessary. However, it may be more complex and / or slower for a communication device to continue receiving additional data (e.g., MBS data 560) via a PTP MBS bearer established or re-established after a radio link failure than it would be for a conventional DRB.

[0123] In one embodiment, the PTP MRB 776 is a conventional DRB.

[0124] Therefore, the communication device 270 can receive MBS data 560 after a wireless link failure.

[0125] According to some embodiments, the communication device 270 performs radio link measurements and periodically evaluates radio link failure criteria. The radio link failure criteria may be standardized and / or configured by infrastructure equipment 272 by RRC configuration or reconfiguration.

[0126] In some embodiments, the communication device 270 evaluates implementation-specific criteria, i.e., criteria not defined by a standard specification and not configured by the network. These are referred to as implementation-specific criteria. Accordingly, steps disclosed herein, such as steps requesting a transition to idle or inactive mode, performing cell selection, and / or establishing or re-establishing a bearer to receive further MBS data, may be responses determining that a predetermined, implementation-specific criterion has been met.

[0127] In some embodiments, when evaluating implementation-specific criteria, the communication device does not perform radio link monitoring and / or reference signal received power (RSRP) or reference signal received quality (RSRQ) measurements.

[0128] In some embodiments, MBS data may be received via a dedicated multicast bandwidth portion (BWP). If the MBS service is the only service that the communication device 270 receives in RRC connection mode, the communication device 270 may consist only of a dedicated multicast BWP.

[0129] In some embodiments, implementation-specific criteria are evaluated if the communication device 270 consists of only a single BWP used to receive MBS services. In some embodiments, implementation-specific criteria are evaluated if the communication device 270 receives MBS services via a PTM bearer.

[0130] In some embodiments, in response to determining that implementation-specific criteria are met, the communication device may perform one or more steps (such as cell selection) as if it had determined that a radio link failure had occurred (based on predetermined standardized or configured criteria). For example, the steps following step S508 in Figures 5, 6, and 7 may be taken as a response determining that implementation-specific criteria have been met.

[0131] In some embodiments, implementation-specific criteria are applicable to HARQ statistics and / or channel state information (CSI) measurements.

[0132] In some embodiments, implementation-specific criteria may be based on statistics or measurements reported to infrastructure equipment to provide feedback related to the delivery of MBS services via PTM transmissions.

[0133] In some embodiments, the predetermined conditions evaluated in step S707a in the example of Figure 7 may be implementation-specific criteria.

[0134] These are called implementation-specific criteria, but they can be based, at least in part, on criteria or parameters that are standardized, configured by a network, or a combination of these. For example, if the nature of the feedback associated with a PTM bearer is set by a network, the implementation-specific criteria may be related to the parameters reported in (or used to obtain) such feedback. For example, if the network requires specific acknowledgment information regarding MBS data, implementation-specific criteria may be based on that acknowledgment information.

[0135] Therefore, embodiments of this technology can reduce the complexity and processing required when receiving MBS data compared to those required when a conventional DRB is configured in RRC connection mode. Furthermore, embodiments can provide evaluation of criteria based on measurements or other information that need to be determined in order to provide requested feedback to the network.

[0136] Figure 8 is a process flow diagram of a process that may be performed by a communication device according to an embodiment of the present technology. It will be understood that in some embodiments, steps may be added, modified, deleted, and / or rearranged.

[0137] The process in Figure 8 begins at step S802, when the communication device 270 enters RRC connection mode. In some embodiments, the communication device 270 may instead enter a different RRC mode, such as RRC inactive mode. Step S802 may be performed solely to obtain MBS service. Thus, one or more conventional steps (e.g., establishing a DRB for non-MBS data transmission, and / or establishing an SRB2) may be omitted.

[0138] In step S804, the communication device 270 receives MBS data. This is done via a PTP or PTM bearer and can use the communication resources of a specific BWP configured for sending multicast data.

[0139] In step S806, the communication device 270 performs a measurement of the wireless link quality. The wireless link quality may be based on one or more of the following: the received signal strength, the received signal quality, or the number or rate of errors detected.

[0140] In step S808, the communication device 270 may evaluate a second criterion to determine whether to request the transmission of MBS data via a different type of bearer. The second criterion may only be met (or evaluated) if the communication device 270 is currently receiving MBS data via a bearer that cannot be re-established by the re-establishment procedure.

[0141] The second criterion may be based on radio link parameters, such as those measured in step S806. The second criterion may be defined and / or standardized by the network. In some embodiments, a communication device may receive instructions for the second criterion transmitted by infrastructure equipment, for example, in system information, by an RRC configuration message, or as part of step S802.

[0142] The second criterion is evaluated, and if it is met, the control proceeds to step S810; otherwise, the control proceeds to step S812.

[0143] In step S810, the communication device 270 sends a request to receive MBS data via a different type of bearer. For example, the communication device may request to receive MBS data via a PTP bearer or via a DRB.

[0144] When the communication device 270 receives a response to a request, it reconfigures its receiver to receive MBS data through the new bearer.

[0145] The control then proceeds to step S812.

[0146] In step S812, the communication device 270 determines whether a first criterion is met. The first criterion is configured or standardized and associated with a radio link failure criterion, which can determine whether the communication device is able to continue receiving MDS data in the current RRC mode. If these criteria are met, control proceeds to step S814. Otherwise, control returns to step S804.

[0147] In step S814, the communication device 270 may determine that a radio link failure has occurred. This may be based on conventional radio link failure criteria, or on implementation-specific criteria as described elsewhere herein, such as based on feedback measurements provided to the network. This determination may trigger other actions according to prior art. For example, a notification may be issued to higher protocol layer entities within the communication device 270.

[0148] In step S816, the communication device 270 may perform cell selection. This may be based on prior art and / or may include criteria relating to the communication device 270's ability to receive MBS data within candidate cells indicated by system information, otherwise the communication device 270 may select such cells that receive MBS data.

[0149] In steps S818 and (if performed, step S819), the communication device 270 can determine whether or not to re-establish the connection. In some embodiments, these steps may be omitted, and control may proceed directly to step S820.

[0150] In the example in Figure 8, the decisions in steps S818 and S819 follow the conventional decision criteria, which allows a positive decision only if AS security is activated during the evaluation in step S812 (step S818, yes), and both DRB and SRB2 are established for communication device 270 (step S819, yes).

[0151] If it is determined that re-establishment is necessary, the control proceeds to step S820.

[0152] In step S820, a re-establishment request is sent to the infrastructure equipment of the selected cell. This re-establishment request may include instructions for the MBS service, or an MBS bearer previously used to receive data related to the MBS service.

[0153] Infrastructure device 270 can establish or re-establish a bearer. The bearer may be for receiving data associated with the MBS service. If a bearer is not suitable for receiving MBS data, communication device 270 may request the establishment or access of such a bearer.

[0154] Next, the process proceeds to step S822, in which the communication device 270 receives further data related to the MBS service.

[0155] If it is determined in step S818 that AS security is not activated ("no"), control moves to step S828, and the communication device 270 enters RRC idle mode.

[0156] If, in step S819, it is determined that either or both of the SRB2 and DRB are not set up, i.e., no attempt is made to re-establish them, then control proceeds to step S824. In step S824, prior to step S814, it is determined whether the communication device 270 has received an inactive mode configuration. If yes, then control proceeds to step S826, and the communication device 270 enters RRC inactive mode.

[0157] If no inactive mode configuration is received, control proceeds to step S828, and the communication device 270 enters RRC idle mode.

[0158] Following steps S826 and S828, the control proceeds to step S822, in which the communication device 270 receives further MBS data in a new RRC state.

[0159] The above describes an example of processing that combines a sequence of steps and messages. However, the scope of this disclosure is not limited to such specific combinations, and in some embodiments, the described steps and messages may be omitted, combined in a different way or order, or otherwise modified. Features or steps described in the context of one example may be combined with features or steps described in the context of another example.

[0160] In particular, Figures 5, 6, 7, and 8 illustrate various embodiments within the scope of this disclosure. These embodiments can be combined in ways other than those shown and described above. In particular, certain steps can be added, modified, deleted, and / or rearranged. The resulting combinations are examples that fall within the scope of this disclosure.

[0161] In some embodiments, the communication device may be configured to select from one or more such examples in response to instructions from infrastructure equipment. These instructions may form part of the RRC configuration or be transmitted, for example, within system information.

[0162] For example, infrastructure equipment may, in response to a detection of a radio link failure occurring while receiving MBS data, send instructions indicating whether (and under what conditions, if permitted) a communication device is authorized to re-establish the connection. An example of such a situation is when MBS data is received via a PTP MRB. Therefore, in such an example, the communication device may determine whether the conditions are met based on its determination that a wireless link failure has occurred, and then perform subsequent steps according to instructions received from the network.

[0163] This describes how a communication device can receive data associated with a service that is a multicast or broadcast service. Steps to establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, In the first RRC mode described above, the steps include measuring the radio link quality associated with the radio access interface, Based on the above wireless link quality, a step is to determine whether a predetermined standard has been met, After determining that the above-mentioned criteria have been met, the step of receiving further data related to the above-mentioned service, Includes, The above data is transmitted using the communication resources of the above wireless access interface. The above-mentioned predetermined criteria are the criteria for continuing to receive the above-mentioned data related to the above-mentioned service in the above-mentioned first RRC mode within the above-mentioned cell.

[0164] Furthermore, it describes how a communication device can receive data associated with a service that is a multicast or broadcast service. This method is Steps to establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, A second step of determining whether the prescribed criteria have been met, If it is determined that the second specified criterion described above has been met, the step of sending a point-to-point (PTP) bearer request is: Includes, The above data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The above PTP bearer request requests parameters for the PTP bearer to receive the above data related to the above service.

[0165] Furthermore, it describes how infrastructure equipment can transmit data associated with services that are multicast or broadcast services. This method is The steps include transmitting the above data related to the above service to a first RRC mode communication device, The steps include receiving a re-establishment request transmitted by the above-mentioned communication device and Includes, If the above re-establishment request was received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device.

[0166] Furthermore, it describes how infrastructure equipment can transmit data associated with services that are multicast or broadcast services. This method is The steps include establishing an RRC connection with a communication device within a single cell, The steps include: sending the above data related to the above service within the above cell; The steps include receiving a point-to-point (PTP) bearer request transmitted by the above-mentioned communication device, and Includes, The above data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The above PTP bearer request requests parameters for the PTP bearer to receive the above data related to the above service.

[0167] The corresponding devices, circuits, and computer-readable media were also described.

[0168] While this disclosure focuses in some respects on implementations in LTE-based and / or 5G networks to provide specific examples, it should be understood that the same principles may be applicable to other radio telecommunications systems. Therefore, while the terms used herein are generally identical or similar to those of the LTE and 5G standards, this teaching is not limited to the current versions of LTE and 5G, and can similarly apply to any suitable device that is not based on LTE or 5G and / or does not conform to any other future version of LTE, 5G, or any other standard.

[0169] It should be noted that the various exemplary approaches described herein may rely on predetermined / predefined information, in the sense that it is known to both the base station and the communication device. Such predetermined / predefined information can generally be established, for example, by definitions in operating standards for radio telecommunications systems, or in signaling previously exchanged between the base station and the communication device, for example, in system information signaling, or in relation to radio resource control setup method signaling, or in information stored in a SIM application. In other words, the specific method by which relevant predetermined information is established and shared among the various elements of the radiotelecommunication system is not of paramount importance to the principles of operation described herein. Furthermore, the approaches of the various examples described herein depend on the information exchanged / communicated among the various elements of the radiotelecommunication system, and such communication may generally be carried out in accordance with prior art, for example, with respect to a specific signaling protocol and the type of communication channel used, unless otherwise required by other contexts. In other words, the specific way in which relevant information is exchanged between various elements of a wireless telecommunications system is not of paramount importance to the principles of operation described herein.

[0170] It is understood that the principles described herein are not applicable only to specific types of communication devices, but are more generally applicable to any type of communication device, for example, to any type of communication device that receives multicast or broadcast data.

[0171] Further specific preferred embodiments of the present invention are described in the appended independent and dependent claims. It is understood that the features of the dependent claims may be combined with the features of the independent claims in combinations other than those expressly described in those claims.

[0172] Accordingly, the foregoing discussion merely discloses and describes exemplary embodiments of the invention. As those skilled in the art will understand, the invention can be carried out in other specific forms without departing from its spirit or essential features. Accordingly, the disclosure of the invention is intended to be illustrative, but not to limit the scope of the invention or the other claims. This disclosure includes any readily identifiable variations of the teachings herein and partially defines the scope of the terms of the foregoing claims so as not to restrict the subject matter of the invention to the public.

[0173] Each feature of this disclosure is defined by the following numbered paragraphs. 1. A method for receiving data associated with a service that is a multicast or broadcast service on a communication device, Steps to establish an RRC connection within a single cell, In a first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, In the first RRC mode, the steps include measuring the radio link quality associated with the radio access interface, A step of determining whether predetermined criteria have been met based on the wireless link quality, After determining that the predetermined criteria have been met, the step of receiving further data related to the service, Includes, The aforementioned data is transmitted using the communication resources of the wireless access interface. The predetermined criteria are the criteria for continuing to receive the data related to the service in the first RRC mode within the cell. method. 2. The step of sending a re-establishment request message when it is determined that the predetermined criteria have been met. The method described in 1. 3. When the aforementioned criteria are met, a data radio bearer (DRB) is not established for the communication device. The method described in 1 or 2. 4. A signal radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device when the criteria for radio link failure were met. The method described in one of the following three ways. 5. The signaling wireless bearer is a signaling bearer dedicated to transmitting uplink or downlink information messages that encapsulate NAS messages. The method described in 4. 6. The step of receiving a re-establishment response message, The step of entering the first RRC mode and Includes, The re-establishment response message is transmitted in response to the re-establishment request message. One of the methods described in 2-5. 7. The re-establishment response message includes instructions for parameters related to the new radio bearer, The step of receiving the further data relating to the service includes receiving the data via the new wireless bearer. The method described in 6. 8. The new wireless bearer is a point-to-multipoint bearer. The method described in 7. 9. When in the first RRC mode, the step of receiving the further data relating to the service includes receiving the data relating to the service. The method described in any one of 1-8. 10. In response to the determination that the predetermined criteria have been met, the system enters a second RRC mode, The step of receiving the further data relating to the service includes receiving the further data relating to the service when in the second RRC mode. The method described in 1. 11. The second RRC mode described above is the RRC idle mode. Method 10. 12. The second RRC mode described above is an RRC inactive mode, The first RRC mode includes receiving an inactive mode configuration. Method 10. 13. The process includes a step of determining whether an inactive mode configuration has been received in the first RRC mode in response to the determination that the predetermined criteria have been met. Entering the second RRC mode is the response to the determination of whether or not an inactive mode configuration was received in the first RRC mode. The method described in one of 10 to 12. 14. The process includes the step of performing a cell selection in response to the determination that the predetermined criteria have been met. The method described in one of the following 1-13. 15. The process includes a step of determining that a wireless link failure has occurred in response to the determination that the predetermined criteria have been met. The method described in one of the following 1-14. 16. Includes the step of receiving one or more instructions of the predetermined criteria. Method 1 through 15. 17. One or more of the aforementioned predetermined criteria are received in the RRC reconstruction message. The method described in 16. 18. The aforementioned predetermined criteria are implementation-specific criteria. Method 1 through 15. 19. In the first RRC mode described above, the communication device consists of a single bandwidth portion for receiving MBS data. The method described in any one of 1 to 18. 20. The step of receiving further data related to the service includes receiving the further data via a point-to-multipoint (PTM) bearer. The method described in any one of the following 1-19. 21. The step of receiving the data relating to the service includes receiving the data via a point-to-multipoint bearer, The aforementioned method, Before determining that the aforementioned predetermined criteria have been met, it is determined that the second predetermined criterion has been met, A response determining that the second predetermined criterion has been met includes sending a point-to-point (PTP) bearer request requesting PTP bearer parameters for receiving the data related to the service. The method described in one of the following 1-20. 22. Includes receiving a PTP bearer response that is transmitted in response to the PTP bearer request and indicates parameters related to a PTP bearer for receiving the data related to the service. The method described in 21. 23. Includes the step of receiving instructions for the second predetermined criterion described above. The method described in 21 or 22. 24. The step of receiving further data related to the service includes receiving the further data via a point-to-point (PTP) bearer. The method described in either 1-19 or 21-23. 25. The PTP bearer is a data radio bearer. Method 24. 26. A method for receiving data associated with a service that is a multicast or broadcast service on a communication device, Steps to establish an RRC connection within a single cell, In a first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, A second step of determining whether the prescribed criteria have been met, If it is determined that the second predetermined criterion is met, the step of sending a point-to-point (PTP) bearer request: Includes, The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. method. 27. The above-mentioned first RRC mode is the RRC connection mode. The method described in section 26. 28 A method for transmitting data associated with a service that is a multicast or broadcast service using infrastructure equipment, The steps include transmitting the data related to the service to a first RRC mode communication device, The steps include receiving a re-establishment request transmitted by the aforementioned communication device, and Includes, If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. method. 29. Includes the step of sending a re-establishment response message, The re-establishment response message is transmitted in response to the re-establishment request message. The method described in 28. 30. The re-establishment response message includes instructions for parameters related to the new radio bearer, The step includes transmitting the further data relating to the service via the new wireless bearer. The method described in section 29. 31. The new wireless bearer is a point-to-multipoint bearer. Method 30. 32. Includes the step of sending instructions that meet one or more predetermined criteria, The re-establishment request is transmitted by the communication device in response to the determination that the predetermined criteria have been met. The method described in any one of the following two to three methods. 33. The step of transmitting the data relating to the service to the communication device includes transmitting the data via a point-to-multipoint bearer, This includes receiving a point-to-point bearer request transmitted by the communication device before receiving the re-establishment request, and requesting parameters for the PTP bearer to receive the data related to the service. The method described in any one of the following two methods (28-32). 34. Includes transmitting a PTP bearer response that is transmitted in response to the PTP bearer request and indicates parameters related to a PTP bearer for receiving the data related to the service. The method described in 33. 35. Including sending instructions for the second prescribed standard, The point-to-point bearer request is transmitted by the communication device in response to a determination that the second predetermined criterion has been met. The method described in 33 or 34. 36. A method for transmitting data associated with a service that is a multicast or broadcast service using infrastructure equipment, The steps include establishing an RRC connection with a communication device within a single cell, The steps include transmitting the data related to the service within the cell, The steps include receiving a point-to-point (PTP) bearer request transmitted by the aforementioned communication device, and Includes, The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. method. 37. A communication device that operates on a wireless communication network, A transmitter configured to transmit signals on a wireless access interface provided by the infrastructure equipment of the aforementioned wireless communication network, A receiver configured to receive signals representing data related to a service that is a multicast or broadcast service on the aforementioned wireless access interface, Controller and It is equipped with, The controller, when the communication device is, Establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, within the cell, the data related to the service is received, In the first RRC mode described above, the radio link quality related to the radio access interface is measured, Based on the aforementioned wireless link quality, it is determined whether a predetermined standard has been met, and, After determining that the aforementioned predetermined criteria have been met, the system receives further data related to the service. The transmitter and receiver are configured to be controlled in such a way that they can operate. The aforementioned data is transmitted using the communication resources of the wireless access interface. The predetermined criteria are the criteria for continuing to receive the data related to the service in the first RRC mode within the cell. Communication device. 38. Circuit for a communication device operating in a wireless communication network, A transmitter circuit configured to transmit signals on a wireless access interface provided by the infrastructure equipment of the aforementioned wireless communication network, A receiver circuit configured to receive signals representing data related to a service that is a multicast or broadcast service on the aforementioned wireless access interface, Controller circuit and It is equipped with, The controller circuit is configured such that the communication device Establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, within the cell, the data related to the service is received, In the first RRC mode described above, the radio link quality related to the radio access interface is measured, Based on the aforementioned wireless link quality, it is determined whether a predetermined standard has been met, and, After determining that the aforementioned predetermined criteria have been met, the system receives further data related to the service. The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. The aforementioned data is transmitted using the communication resources of the wireless access interface. The predetermined criteria are the criteria for continuing to receive the data related to the service in the first RRC mode within the cell. Circuitry for communication devices. 39. A communication device that operates on a wireless communication network, A transmitter configured to transmit signals on a wireless access interface provided by the infrastructure equipment of the aforementioned wireless communication network, A receiver configured to receive signals representing data related to a service that is a multicast or broadcast service on the aforementioned wireless access interface, Controller and It is equipped with, The controller, when the communication device is, Establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, within the cell, the data related to the service is received, Determine whether the second set of criteria has been met, and If it is determined that the second predetermined criterion is met, a point-to-point (PTP) bearer request is sent. The transmitter and receiver are configured to be controlled in such a way that they can operate. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Communication device. 40. Circuit for a communication device operating in a wireless communication network, A transmitter circuit configured to transmit signals on a wireless access interface provided by the infrastructure equipment of the aforementioned wireless communication network, A receiver circuit configured to receive signals representing data related to a service that is a multicast or broadcast service on the aforementioned wireless access interface, Controller circuit and It is equipped with, The controller circuit is configured such that the communication device Establish an RRC connection within a single cell, In the first radio resource control (RRC) mode, within the cell, the data related to the service is received, Determine whether the second set of criteria has been met, and If it is determined that the second predetermined criterion is met, a point-to-point (PTP) bearer request is sent. The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Circuitry for communication devices. 41. Infrastructure equipment that provides a wireless access interface and is used in a wireless communication network, A transmitter configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver configured to receive signals, Controller and It is equipped with, The controller is the infrastructure equipment, The data related to the service is transmitted to a first RRC mode communication device, and The re-establishment request transmitted by the aforementioned communication device is received The transmitter and receiver are configured to be controlled in such a way that they can operate. If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. Infrastructure equipment. 42. Circuits for infrastructure equipment that provide a wireless access interface and are for use in wireless communication networks, A transmitter circuit configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver circuit configured to receive a signal, Controller circuit and It is equipped with, The controller circuit is configured such that the infrastructure equipment The data related to the service is transmitted to a first RRC mode communication device, and The re-establishment request transmitted by the aforementioned communication device is received The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. Circuits for infrastructure equipment. 43. Infrastructure equipment that provides a wireless access interface and is used in a wireless communication network, A transmitter configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver configured to receive signals, Controller and It is equipped with, The controller is the infrastructure equipment, Establish an RRC connection with a communication device within a single cell, The data related to the service is transmitted within the cell, and The communication device receives a point-to-point (PTP) bearer request transmitted by the aforementioned communication device. The transmitter and receiver are configured to be controlled in such a way that they can operate. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Infrastructure equipment. 44. Circuits for infrastructure equipment that provide a wireless access interface and are for use in wireless communication networks, A transmitter circuit configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver circuit configured to receive a signal, Controller circuit and It is equipped with, The controller circuit is configured such that the infrastructure equipment Establish an RRC connection with a communication device within a single cell, The data related to the service is transmitted within the cell, and The communication device receives a point-to-point (PTP) bearer request transmitted by the aforementioned communication device. The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Circuits for infrastructure equipment.

[0174] Further specific preferred embodiments of the present invention are described in the appended independent and dependent claims. It is understood that the features of the dependent claims may be combined with the features of the independent claims in combinations other than those expressly described in those claims.

Claims

1. A method for receiving data associated with a service that is a multicast or broadcast service on a communication device, Steps to establish an RRC connection within a single cell, In a first radio resource control (RRC) mode, the steps include receiving the data related to the service within the cell, A second step of determining whether the prescribed criteria have been met, If it is determined that the second predetermined criterion is met, the step of sending a point-to-point (PTP) bearer request: Includes, The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. method.

2. The first RRC mode is the RRC connection mode. The method according to claim 1.

3. A method for transmitting data associated with a service that is a multicast or broadcast service using infrastructure equipment, The steps include transmitting the data related to the service to a first RRC mode communication device, The steps include receiving a re-establishment request transmitted by the aforementioned communication device, and Includes, If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. method.

4. The step includes sending a re-establishment response message, The re-establishment response message is transmitted in response to the re-establishment request message. The method according to claim 3.

5. The re-establishment response message includes instructions for parameters related to the new radio bearer, The step includes transmitting the further data relating to the service via the new wireless bearer. The method according to claim 4.

6. The new wireless bearer is a point-to-multipoint bearer. The method according to claim 5.

7. The step includes sending instructions that meet one or more predetermined criteria, The re-establishment request is transmitted by the communication device in response to the determination that the predetermined criteria have been met. The method according to claim 3.

8. The step of transmitting the data related to the service to the communication device includes transmitting the data via a point-to-multipoint bearer, This includes receiving a point-to-point bearer request transmitted by the communication device before receiving the re-establishment request, and requesting parameters for the PTP bearer to receive the data related to the service. The method according to claim 3.

9. This includes sending a PTP bearer response in response to the PTP bearer request, which indicates parameters related to the PTP bearer for receiving the data related to the service. The method according to claim 8.

10. This includes transmitting instructions for a second set of predetermined criteria, The point-to-point bearer request is transmitted by the communication device in response to a determination that the second predetermined criterion has been met. The method according to claim 8.

11. A method for transmitting data associated with a service that is a multicast or broadcast service using infrastructure equipment, The steps include establishing an RRC connection with a communication device within a single cell, The steps include transmitting the data related to the service within the cell, The steps include receiving a point-to-point (PTP) bearer request transmitted by the aforementioned communication device, and Includes, The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. method.

12. Infrastructure equipment that provides a wireless access interface and is used in wireless communication networks, A transmitter configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver configured to receive signals, Controller and It is equipped with, The controller is the infrastructure equipment, The data related to the service is transmitted to a first RRC mode communication device, and The re-establishment request transmitted by the aforementioned communication device is received The transmitter and receiver are configured to be controlled in such a way that they can operate. If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. Infrastructure equipment.

13. A circuit for infrastructure equipment that provides a wireless access interface and is used in wireless communication networks, A transmitter circuit configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver circuit configured to receive a signal, Controller circuit and It is equipped with, The controller circuit is configured such that the infrastructure equipment The data related to the service is transmitted to a first RRC mode communication device, and The re-establishment request transmitted by the aforementioned communication device is received The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. If the aforementioned re-establishment request is received, it means that a data radio bearer was not established for the communication device, or a signaling radio bearer (SRB) for transmitting encapsulated non-access layer (NAS) messages was not established for the communication device. Circuits for infrastructure equipment.

14. Infrastructure equipment that provides a wireless access interface and is used in wireless communication networks, A transmitter configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver configured to receive signals, Controller and It is equipped with, The controller is the infrastructure equipment, Establish an RRC connection with a communication device within a single cell, The data related to the service is transmitted within the cell, and The communication device receives a point-to-point (PTP) bearer request transmitted by the aforementioned communication device. The transmitter and receiver are configured to be controlled in such a way that they can operate. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Infrastructure equipment.

15. A circuit for infrastructure equipment that provides a wireless access interface and is used in wireless communication networks, A transmitter circuit configured to transmit signals representing data related to a service that is a multicast or broadcast service via the aforementioned wireless access interface, A receiver circuit configured to receive a signal, Controller circuit and It is equipped with, The controller circuit is configured such that the infrastructure equipment Establish an RRC connection with a communication device within a single cell, The data related to the service is transmitted within the cell, and The communication device receives a point-to-point (PTP) bearer request transmitted by the aforementioned communication device. The transmitter circuit and the receiver circuit are configured to be controlled so that they can operate in such a manner. The aforementioned data is transmitted via a point-to-multipoint (PTM) bearer using the communication resources of the radio access interface. The PTP bearer request requests parameters for the PTP bearer to receive the data related to the service. Circuits for infrastructure equipment.

Images