Receiving transmissions from different cells

Abstract

There is provided a method at a user equipment, comprising: receiving information of a transmission schedule from a second cell, where an apparatus can receive from one cell at a time; determining, based on the received transmission schedule, that a transmission from a second cell cannot be received within a limit set by a gap configuration of a first cell with respect to which the apparatus is in a radio resource control (RRC) connected state; transmitting, to a second cell, an indication from the second cell that a transmission cannot be received based on the transmission schedule; and receiving information of the modified transmission schedule from the second cell.

Description

Technical Field

[0001] Various example embodiments generally relate to receiving transmissions from different cells. Background Art

[0002] There are situations where a user equipment (UE) may need to listen to transmissions (e.g., broadcast and unicast) from different cells. However, the UE may have limitations regarding the ability to receive multiple transmissions simultaneously. For example, a UE with limited hardware and software resources (e.g., a single receiver (RX) and a single transmitter (TX) chain) may still be expected to receive broadcast messages from one cell even though it may have unicast communications with the same network or another network from another cell at the same time. Solutions for enabling the UE to receive both transmissions are needed. Summary of the invention

[0003] According to some aspects, the subject matter of the independent claims is provided. Some other aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Hereinafter, the present invention will be described in more detail with reference to embodiments and accompanying drawings, in which

[0005] Figure 1 A network according to an embodiment is presented;

[0006] Figure 2 An example of MCCH transmission according to an embodiment is shown;

[0007] Figure 3 and Figure 4 A method according to some embodiments is shown;

[0008] Figure 5A , Figure 5B and Figure 6 shows a signaling flow diagram according to some embodiments;

[0009] Figures 7 to 10 illustrating different options for modifying a transmission schedule according to some embodiments; and

[0010] Fig.11 and Fig.12 An apparatus according to some embodiments is shown. DETAILED DESCRIPTION

[0011] The following embodiments are exemplary. Although this specification may mention "an", "one" or "some" embodiments in several positions of the text, this does not necessarily mean that each mention is made to the same embodiment, or that a particular feature is only applicable to a single embodiment. The individual features of different embodiments may also be combined to provide other embodiments. For purposes of this disclosure, phrases "at least one of A or B", "at least one of A and B", "A and / or B" mean (A), (B), or (A and B). For purposes of this disclosure, phrases "A or B" and "A and / or B" mean (A), (B), or (A and B). For purposes of this disclosure, phrases "A, B and / or C" mean (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0012] The described embodiments may be implemented in a radio system, such as a radio system including at least one of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS, 3G) based on basic Wideband Code Division Multiple Access (W-CDMA), High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced LTE, and Enhanced LTE (eLTE). The term 'eLTE' here means LTE evolution connected to a 5G core. LTE is also known as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN). The term "resource" may refer to a radio resource, such as a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a subcarrier, a beam, etc. The term "transmit" and / or "receive" may refer to transmitting and / or receiving wirelessly via a wireless propagation channel on a radio resource.

[0013] However, the embodiments are not limited to the systems / RATs given as examples, but those skilled in the art may apply the solution to other communication systems provided with the necessary attributes. An example of a suitable communication system is a 5G system. The 3GPP solution for 5G is called New Radio (NR). 5G has been envisioned to use multiple input multiple output (MIMO) multi-antenna transmission technology, deploy more base stations or nodes (the so-called small cell concept) than the current network of LTE, including macro sites, which operate in conjunction with smaller local access nodes and may also adopt multiple radio technologies for better coverage and enhanced data rates. 5G will likely consist of more than one radio access technology / radio access network (RAT / RAN), each optimized for certain use cases and / or spectrum. 5G mobile communications may have a wider range of use cases and related applications, including video streaming, augmented reality, different data sharing methods, and various forms of machine type applications (including vehicle safety, different sensors, and real-time control). 5G is expected to have multiple radio interfaces, i.e., below 6GHz, cmWave, and mmWave, and can be integrated with existing traditional radio access technologies (such as LTE).

[0014] The current architecture in LTE networks is distributed in the radio and concentrated in the core network. Low-latency applications and services in 5G may need to bring content close to the radio, which leads to local interruptions and multi-access edge computing (MEC). 5G enables analysis and knowledge generation to occur at the data source. The method requires the use of resources that can be discontinuously connected to the network, such as laptops, smart phones, tablet computers and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content near cellular subscribers to obtain faster response times. Edge computing covers a wide range of technologies, such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networking and processing, which can also be classified as local cloud / fog computing and grid / mesh computing, dew computing, mobile edge computing, micro-cloud, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (large-scale connectivity and / or latency-critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, healthcare applications). By leveraging network function virtualization (NVF) and software defined networking (SDN), edge cloud can be brought into the RAN. Using edge cloud can mean that access node operations are at least partially implemented in a server, host or node that is operatively coupled to a remote radio head or base station including radio components. Network slicing allows multiple virtual networks to be built on top of a common shared physical infrastructure. The virtual networks are then customized to meet the specific needs of applications, services, devices, customers or operators.

[0015] In radio communications, node operations may be implemented at least in part in a central / centralized unit (CU) (e.g., a server, host, or node), which is operatively coupled to a distributed unit (DU) (e.g., a radio head / node). Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be understood that the allocation of labor between core network operations and base station operations may vary depending on the implementation. Therefore, the 5G network architecture may be based on a so-called CU-DU split. One gNB-CU controls several gNB-DUs. The term 'gNB' in 5G may correspond to an eNB in ​​LTE. A gNB(s) may communicate with one or more UEs. A gNB-CU (central node) may control multiple spatially separated gNB-DUs, at least serving as transmit / receive (Tx / Rx) nodes. However, in some embodiments, the gNB-DU (also referred to as DU) may include, for example, a radio link control (RLC), a media access control (MAC) layer, and a physical (PHY) layer, while the gNB-CU (also referred to as CU) may include layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an Internet Protocol (IP) layer. Other functional splits are also possible. It can be assumed that the skilled person is familiar with the OSI model and the functions within each layer.

[0016] In an embodiment, a server or CU may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve the process of combining hardware and software network resources and network functions into a single software-based management entity, i.e., a virtual network. Such a virtual network may provide a flexible distribution of operations between servers and radio heads / nodes. In fact, any digital signal processing task may be performed in one of the CU or DU, and the boundaries at which responsibilities are transferred between the CU and DU may be selected according to the implementation.

[0017] Some other technological evolutions that may be used are software defined networking (SDN), big data and all-IP, to mention only some non-limiting examples. For example, network slicing may be in the form of a virtual network architecture using the same principles behind software defined networking (SDN) and network function virtualization (NFV) in fixed networks. SDN and NFV may deliver greater network flexibility by allowing traditional network architectures to be divided into virtual elements that can be linked (also by software). Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customized to meet the specific needs of applications, services, devices, customers or operators.

[0018] Multiple gNBs (access points / nodes), each including a CU and one or more DUs, can be connected to each other via an Xn interface, through which the gNBs can negotiate. The gNB can also be connected to the 5G core network (5GC) via a next generation (NG) interface, which can be the 5G equivalent of the core network of LTE. Such a 5G CU-DU split architecture can be implemented using a cloud / server, so that the CU with higher layers is located in the cloud and the DU is closer to or includes the actual radio and antenna unit. There are similar plans in progress for LTE / LTE-A / eLTE. When both eLTE and 5G will use similar architectures in the same cloud hardware (HW), the next step may be to combine software (SW) so that one common SW controls two radio access networks / technologies (RAN / RAT). This can allow new ways to control the radio resources of two RANs. In addition, it is possible to have a configuration in which the complete protocol stack is controlled by the same HW as the CU and processed by the same radio unit as the CU.

[0019] It should also be understood that the distribution of labor between core network operations and base station operations may be different from that of LTE or even non-existent. Some other technology evolutions that may be used are big data and all-IP, which may change the way networks are built and managed. 5G (or New Radio, NR) networks are designed to support multiple layers, where MEC servers can be placed between the core and base stations or Node Bs (gNBs). It should be understood that MEC can also be applied to 4G networks.

[0020] 5G can also make use of satellite communications to enhance or supplement the coverage of 5G services, for example by providing backhaul. Possible use cases are to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers in vehicles, or to ensure service availability for critical communications and future rail / maritime / aeronautical communications. Satellite communications can make use of geosynchronous orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular mega constellations (systems in which hundreds of (nano) satellites are deployed). Each satellite in a mega constellation can cover several satellite-enabled network entities creating ground cells. Ground cells can be created by ground relay nodes or by gNBs located on the ground or in satellites.

[0021] Embodiments may also be applicable to narrowband (NB) Internet of Things (IoT) systems, which can use cellular telecommunication bands to connect a wide range of devices and services. NB-IoT is a narrowband radio technology designed for the Internet of Things (IoT) and is one of the technologies standardized by the Third Generation Partnership Project (3GPP). Other 3GPP IoT technologies that are also suitable for implementing embodiments include machine type communication (MTC) and eMTC (enhanced machine type communication). NB-IoT specifically focuses on low cost, long battery life, and enabling a large number of connected devices. NB-IoT technology is deployed "in-band" (using resource blocks within a normal LTE carrier) in the spectrum allocated to Long Term Evolution (LTE) or in unused resource blocks within the guard band of an LTE carrier, or "standalone" in a dedicated spectrum.

[0022] Embodiments may also be applicable to device-to-device (D2D), machine-to-machine, point-to-point (P2P) communications. Embodiments may also be applicable to vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), infrastructure-to-vehicle (I2V), or generally to V2X or X2V communications.

[0023] Figure 1 An example of a communication system to which an embodiment of the present invention can be applied is shown. The system may include a control node 110 that provides one or more cells (such as cell 100), and a control node 112 that provides one or more other cells (such as cell 102). For example, each cell may be, for example, a macro cell, a micro cell, a femto cell, or a micro cell. In another viewpoint, a cell may define a coverage area or a service area of ​​a corresponding access node. The control nodes 110, 112 may be an evolved node B (eNB) such as in LTE and LTE-A, an ng-eNB such as in eLTE, a gNB of 5G, or any other device capable of controlling radio communications and managing radio resources within a cell. The control nodes 110, 112 may be referred to as base stations, network nodes, or access nodes.

[0024] The system may be a cellular communication system consisting of a radio access network of access nodes, each access node controlling a corresponding cell or cells. The access node 110 may provide wireless access to other networks such as the Internet for user equipment (UE) 120 (one or more UEs). The wireless access may include downlink (DL) communications from a control node to UE 120 and communications from UE 120 to a control node.

[0025] Additionally, although not shown, one or more local area access nodes may be arranged so that the cell provided by the local area access node overlaps at least partially with the cell of access node 110 and / or 112. The local area access node may provide wireless access within a subcell. Examples of subcells may include micro, pico and / or femto cells. Typically, a subcell provides a hotspot within a macrocell. The operation of a local area access node may be controlled by an access node under whose control area the subcell is provided. In general, a control node for a small cell may also be referred to as a base station, a network node, or an access node.

[0026] There may be multiple UEs 120, 122 in the system. Each of them may be served by the same or different control nodes 110, 112. The UEs 120, 122 may communicate with each other with a D2D communication interface established between them.

[0027] The term "terminal device" or "UE" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS) or access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback application, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), an Internet of Things (IOT) device, a watch or other wearable, a head mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), consumer electronic devices, devices operating on a commercial and / or industrial wireless network, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0028] In the case of multiple access nodes in a communication network, the access nodes can be connected to each other using an interface. The LTE specification calls for interfaces such as the X2 interface. For IEEE802.11 networks (i.e., wireless local area networks, WLAN, WiFi), a similar interface Xw can be provided between access points. The interface between an eLTE access point and a 5G access point or between two 5G access points may be referred to as Xn. Other communication methods between access nodes may also be possible. Access nodes 110 and 112 may also be connected to a core network 116 of a cellular communication system via another interface. The LTE specification specifies the core network as an evolved packet core (EPC), and the core network may include a mobility management entity (MME) and a gateway node. The MME may handle the mobility of a terminal device in a tracking area including multiple cells, and handle the signaling connection between the terminal device and the core network. The gateway node may handle data routing in the core network and data routing to / from the terminal device. The 5G specification specifies the core network as the 5G Core (5GC), and the core network may include, for example, the Access and Mobility Management Function (AMF) and the User Plane Function / Gateway (UPF), to name a few. The AMF may handle termination of non-access stratum (NAS) signaling, NAS encryption and integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. For example, the UPF node may support packet routing and forwarding, packet inspection, and QoS processing.

[0029] As described above, a UE may be required to simultaneously receive unicast and MBS broadcasts from different cells of the same or different networks / operators (e.g., unicast from a first cell and Multicast and Broadcast Service (MBS) from a second cell). The UE may share its hardware and software resources between those broadcast and unicast receptions, which in turn may result in limitations in unicast transmission / reception (e.g., receive and transmit chains) for UEs with limited hardware and software resources. In the case of different operators (e.g., the UE receives unicast from one cell and broadcast from another cell from another network), the UE may use multiple SIMs (MUSIMs), one SIM for each operator. For example, Figure 1 Cell 100 may be provided by one operator, while cell 102 may be provided by another operator.

[0030] Considering MBS as a required transmission from the second cell, the Rel-17 MBS work item has specified broadcast reception for UEs that can be in IDLE / INACTIVE / CONNECTED Radio Resource Control (RRC) state. In order for a UE to receive MBS broadcast in RRC_IDLE / RRC_INACTIVE mode: • System Information Block (SIB) 20 includes information required for a UE to receive Multicast Control Channel (MCCH) information including a repetition period and a configured transmission / reception / monitoring window for the MCCH. MCCH information is transmitted periodically by the gNB using a configurable repetition period and within a configured transmission window (also called a reception or monitoring window, or MCCH window). MCCH information is control information used by the UE to understand which broadcast services are provided in the cell and scheduling information for receiving broadcast data. For example, MCCH provides information about the Multicast Traffic Channel (MTCH) (i.e., the data channel in which the broadcast service is provided). This information includes search space for UE to be able to receive the relevant MTCH, discontinuous reception (DRX) information, etc. Each temporary multicast group identifier (TMGI) (mapped to a specific MTCH, TMGI is an identifier of a specific broadcast service). ·UE reads and decodes SIB20 message and understands the configuration / scheduling details of MCCH. Then, The UE reads the MCCH to know which services are provided in the cell and their scheduling information.

[0031] For UEs in RRC_CONNECTED mode, SIB reading may be bypassed since the UE is provided with the search space configuration to receive MCCH within PDCCH_ConfigCommon.

[0032] The UE may have MUSIM capabilities when receiving transmissions from different operators. The multi-SIM work items in Rel-17 focus on providing support for MUSIM operation for single RX / single TX or dual RX / single TX devices. Due to limited UE capabilities, the supported scenarios are where the UE can be in RRC_IDLE or RRC_INACTIVE state in one cell and in RRC_CONNECTED, RRC_INACTIVE or RRC_IDLE in another cell. Enhanced mobile broadband (eMBB) devices may have several receiver (RX) and transmitter (TX) chains to be able to support higher bandwidths (carrier aggregation (CA) / dual connection (DC) scenarios). However, even if the hardware capabilities would allow parallel MUSIM operation (i.e., the UE is RRC_CONNECTED in 2 different cells), most current devices do not allow parallel MUSIM operation due to hardware (HW) and software (SW) design complexity (including two parallel basebands, protocol stacks and coordinated implementations) and / or complex verification. So, in general, a single SW architecture is applied.

[0033] This may cause problems because a MUSIM UE with a single RX chain cannot perform RRC_IDLE / INACTIVE operation in one network while being in RRC_CONNECTED with another network, i.e., it is not possible to receive any data from different cells at the same time. For example, a possible problematic scenario could be monitoring paging from one cell while being in RRC_CONNECTED state with another network. In addition, a MUSIM UE with a single RX chain cannot monitor paging on more than one network at the same time.

[0034] As a solution to these problematic situations, Rel-17 has specified, for example, the following: • The UE may request and receive periodic or aperiodic gaps for cells where the UE is in RRC_CONNECTED state, e.g., for paging, measurements, etc. performed on cells where the UE is in RRC_IDLE / RRC_INACTIVE. The maximum periodic / aperiodic gap duration for Rel-17 may be limited to 20ms. If the UE decides to move to RRC_CONNECTED with another network, the UE may leave the current RRC_CONNECTED cell (and enter RRC_IDLE). Compared to Rel-16, after the UE has requested the network to release the RRC connection, the UE may enter RRC_IDLE autonomously without network configuration after a (pre-)configured waiting time. In this case, the network is aware of the UE leaving because the UE may inform it of the leaving using RRC assistance information (using e.g. the RRCUEAssistanceInformation message). If the network releases the UE by RRC release, it may take into account the indicated UE preference regarding the d RRC state after the RRC connection is released. • If the UE is paged in a cell in which it is in RRC_INACTIVE / RRC_IDLE, but decides not to respond to the paging, the UE may send a BUSY indication to the network. The paging cause (voice / non-voice) is added to the paging message so that the UE can decide whether it should leave / release the connection with the network in which the UE was originally in RRC_CONNECTED, And connect to another network where the UE was originally in RRC_INACTIVE / RRC_IDLE.

[0035] However, additional problems may arise with certain types of transmissions from the second cell, such as MBS. Figure 2The MCCH transmission / repetition operation in a Rel-17 MBS based cell is shown. MCCH information (Physical Downlink Control Channel (PDCCH), and subsequently Physical Downlink Shared Channel (PDSCH) scrambled via MCCH-RNTI) is transmitted by the gNB in ​​the MCCH window every "repetition period" configured in SIB20 and monitored by the UE. During this window, the UE attempts to blindly decode the MCCH-RNTI. Exactly the same information is repeated during the modification period, i.e. the MCCH information transmitted by the gNB does not change during this period. The MCCH information may change in the next modification period, for example, when a broadcast service starts / ends, etc. This can be indicated by a change notification in the PDCCH that schedules the MCCH. Based on the current standard specifications, the MCCH window duration can be [2-160] time slots.

[0036] In addition, for each MTCH (mapped to one or several broadcast services), using the MCCH information the UE can be configured with a DRX cycle in which the UE needs to wake up and attempt to decode the actual broadcast data transmission (PDCCH and subsequent PDSCH scrambled via the G-RNTI). Based on the current standard specification, the DRX on duration for each G-RNTI can be [1-1600] ms.

[0037] Therefore, in order to receive broadcast services in RRC_IDLE / RRC_INACTIVE state (provided via the second cell), the UE may need to periodically monitor information in the MCCH in addition to monitoring the data itself within the DRX cycle of each G-RNTI. Assuming that the maximum allowed gap in the RRC connection will be similar to the maximum periodic / aperiodic gap duration agreed for MUSIM operation (musim-GAPLength of Rel-17), the gap length will be limited to 20ms. Therefore, the UE can only expect a gap in its DL / UL scheduling without leaving the RRC connection from the first cell and monitor any MCCH / MTCH in the second cell for a duration of 20ms, which may not be enough in the actual situation considering MCCH monitoring / MTCH monitoring for each G-RNTI. It would be inefficient to keep the RRC connection in the first cell for each MCCH. Allowing longer gaps with the expected MCCH window length for MBS operation will result in unacceptable performance degradation in the ongoing RRC connection.

[0038] A measurement gap or scheduling gap is an opportunity given to the UE to perform measurements on a downlink signal. This is because the UE may not be able to perform inter-frequency or inter-RAT measurements / monitoring while also transmitting or receiving with another connected cell. Even for intra-frequency measurements, a 5G UE may need measurement gaps if such measurements are to be performed outside the UE's currently active bandwidth part (BWP). The network (e.g., the connected cell) configures measurement gaps for the UE via RRC signaling. The network configures these gaps so that they are not consistent with UE transmissions or receptions from the connected cell. The gap configurations that define, for example, the measurement gap repetition period MGRP (if periodic), the gap offset (specifying the start subframe), and the measurement gap length can be changed later at the UE's request or by the network. The UE may be configured with multiple measurement gaps, or the UE may apply autonomous gaps. The UE's RRC layer typically notifies Layer 1 of the gaps. Layer 1 follows these gaps for making measurements, for monitoring transmissions of other cells, etc. The entire measurement gap is typically not used for measurement. The UE needs some time to re-tune its RF transceiver. Therefore, the actual measurement duration may be less than the measurement gap length.

[0039] Therefore, one problem is that the network does not know whether the broadcast session is received by the UE, because any UE in the geographic area (e.g., cell 102) that is authorized by the network node 112 to receive data can receive the broadcast service. Therefore, the cell does not know whether all UEs are able to properly decode, for example, the MCCH, etc., because there is no feedback mechanism. Therefore, the gNB 112 is free to determine how large the MCCH window will be and how the DRX cycle for each G-RNTI is scheduled. If these do not meet the maximum gap that the UE can obtain from the other network (or any other UE restrictions), the UE may have problems receiving transmissions from the second cell 102.

[0040] To address these issues, a solution for UE and gNB is proposed such that a UE that is expected to receive a transmission (e.g., broadcast service, MBS) from a second cell while it may have unicast communication with the same or another network from a first cell is able to receive MBS transmissions. It is assumed that the UE has limitations that do not allow the UE to receive from two networks simultaneously (e.g., a single RX chain, or otherwise limited hardware and software resources). Therefore, the UE may receive transmissions from at most one cell at a time. Although such a UE is used as an example: a MUSIM UE that is in RRC_CONNECTED state in one network corresponding to its first SIM (e.g., a first cell 100 from a first operator) and in RRC_IDLE / RRC_INACTIVE state in another network corresponding to its second SIM (e.g., a second cell 102 from a second operator), it is noted that the problem and the proposed solution are applicable to any scenario where the UE is expected to simultaneously receive MBS broadcasts from one cell and unicast transmissions from another cell (with the same or different operator).

[0041] It is noted that RRC_CONNECTED, RRC CONNECTED and RRC connected are used interchangeably in the description and drawings. Similarly, RRC_IDLE, RRC IDLE and RRC idle and RRC_INACTIVE, RRC INACTIVE and RRC inactive are used interchangeably.

[0042] Figure 3 An example method is described. The method may be computer-implemented. The method may be performed by a user device (such as, Figure 1 UE 120) executes.

[0043] Accordingly, if Figure 3 As shown, UE 120 may receive information on transmission scheduling from the second cell in step 300, wherein the device is capable of receiving from one cell at a time. Here, gNB 112 is considered to be a network node of the second cell, and gNB 110 is a network node of the first cell to which the UE is currently connected or with which it performs communication. gNB 112 of the second cell 102 may be responsible for transmitting the transmission scheduling of the second cell.

[0044] In an embodiment, the transmission may be an MBS transmission from the second cell 102, but is not limited to an MBS. The transmission schedule may be read from, for example, SIB20 and / or MCCH sent by the gNB 112, in which case the transmission schedule may indicate a broadcast transmission schedule. In the case where the transmission schedule is obtained from SIB20, the transmission schedule may indicate a scheduling of MCCH transmissions. In the case where the transmission schedule is obtained from MCCH, the transmission schedule may indicate a scheduling of MTCH transmissions. In the case where the transmission schedule is obtained from SIB20 and MCCH, the transmission schedule may indicate a scheduling of MCCH and MTCH transmissions. In addition, information of the transmission schedule may be received by the UE 120 via a broadcast transmission from the second cell 120. This may occur when the UE 120 is in an RRC IDLE state or in an RRC inactive state relative to the second cell 102.

[0045] In an embodiment, the transmission schedule includes at least one of a periodicity, a transmission length, or a modified length of control channel information of a broadcast transmission (eg, MCCH) associated with the transmission schedule (eg, indicated in SIB 20).

[0046] In step 302, the UE 120 determines, based on the received transmission schedule, that transmissions from the second cell 102 cannot be received within the limits set by the gap configuration of the first cell 100. The apparatus may be in an RRC connected state with respect to the first cell 100. The gap configuration or a single gap for monitoring other cells may have been received from the gNB 110 of the first cell 100, possibly at the request of the UE 120.

[0047] In an embodiment, the receipt of the information of the transmission schedule in step 500 triggers UE 120 to request a gap configuration for the first cell. When gNB 110 does not schedule communication with UE 120, the gap configuration may define one or more gaps for the first cell.

[0048] In an embodiment, for example, the MCCH window (e.g., the transmission monitoring window for transmissions of the second cell 102) is larger than the defined gap length (or larger than the maximum available gap of the first cell 102), or the repetition period of the MCCH and the periodic gap do not match.

[0049] In step 304, UE 120 transmits an indication to the second cell 102 (e.g., to gNB 112) that the transmission from the second cell 102 cannot be received based on the current transmission scheduling. In an embodiment, the indication may include information of the gap configuration of the first cell 102. In an embodiment, the indication may include at least one of the following: a maximum gap duration that the UE 120 can request from the first cell 100 or a maximum transmission monitoring window (e.g., MCCH window) from the second cell 102 that the UE 120 can tolerate.

[0050] In step 306, UE 120 receives information of a modified transmission schedule from second cell 102. The modification may be based on the indication of step 304. gNB 112 of the second cell may perform the modification so that UE 120 may receive transmission (e.g., MBS) from second cell 102 within the gap of first cell 100.

[0051] Figure 4 An example method is depicted. The method may be computer-implemented. The method may be performed by a network node of the second cell 102 (e.g., gNB 112).

[0052] In step 400, the gNB 112 broadcasts a transmission schedule for the second cell 102. As described above, in an embodiment, this may include, for example, a broadcast of the MCCH and / or SIB20.

[0053] In step 402, the gNB 102 receives an indication from a UE 120 in the second cell 102 that a transmission of the second cell cannot be received based on the current transmission schedule. The indication may include, for example, information about the gap configuration of the first cell 100 and / or a maximum transmission monitoring window from the second cell 102 that the UE 120 can tolerate.

[0054] Based on this indication, in step 404, gNB 102 modifies the transmission schedule. The modified transmission schedule may enable UE 120 to receive transmissions (e.g., MBS) from second cell 102 within the limits set by the gap configuration of first cell 100.

[0055] In an embodiment, modifying the transmission schedule based on the received indication includes reducing a maximum transmission monitoring window associated with transmissions of the transmission schedule (e.g., MCCH), or reducing a window for receiving MTCH from the cell 110. For example, if the maximum available gap length from the first cell 100 is 20 ms, and the current MCCH monitoring window is 40 ms, the length of the MCCH monitoring window may be reduced to 20 ms.

[0056] In an embodiment, modifying the transmission schedule based on the received indication comprises segmenting the transmission of the transmission schedule.This may be combined with transmitting different transmission schedules for different segments to UEs in the cell.

[0057] In yet another embodiment, modifying the transmission schedule based on the received indication includes rearranging the content of the transmissions of the transmission schedule so that the predetermined type of content is transmitted at the beginning of the corresponding transmission window. For example, assume that the MCCH has a length of 40 ms. Based on the rearrangement, the most important data (based on a predetermined criterion) is transmitted at the beginning of the MCCH so that the UE 120 with, for example, a 20 ms gap can receive the first half of the MCCH.

[0058] In an embodiment, in step 402, the gNB 112 receives multiple indications from multiple user equipments in the cell 112, and in step 404, modifies the transmission schedule based on the received multiple indications. The gNB 112 may apply thresholds when deciding whether to perform the modification and when deciding what type of modification to perform on the transmission schedule. For example, when there is a problem that several UEs in the cell 112 do not receive the MBS of the cell 112, and one or only a few (i.e., less than a predetermined threshold) of UEs report a preference for different transmission schedules, the gNB 112 may avoid performing the modification. In yet another embodiment, for example, when several UEs request a modification of the transmission schedule, the gNB 112 may decide to apply the modification and modify the transmission schedule based on the indication from the UE with the most stringent restriction. That is, the gNB 112 may schedule based on the UE with the most stringent restriction, for example, scheduling the MCCH window based on the reported smallest possible maximum MCCH monitoring window or the smallest possible maximum DRX on duration of data that the UE can tolerate. In one embodiment, even one indication triggers the modification of the transmission schedule to be adjusted. In an embodiment, gNB 112 may decide to ignore limitations for some UEs in cases where the network does not consider, for example, the reported maximum DRX on-duration to be sufficient to deliver data.

[0059] In step 406, gNB 102 broadcasts the modified transmission schedule of second cell 102. Similar to the transmission of step 400, the broadcast may be received by UEs within second cell 102. As a result, the UEs in cell 102 become aware of the modified transmission schedule of cell 102.

[0060] Figure 5A and Figure 5BA signaling flow diagram between a UE 120, a gNB 100 of a first cell 100 (also referred to as cell #1), and a gNB 110 of a second cell 102 (also referred to as cell #2) is shown. In step 500, the UE 120 resides in cell #2 in an RRC idle or RRC inactive state. The UE 120 is in an RRC connected state with cell #1. It is assumed that there are currently no ongoing / already started broadcast services of interest to the UE 120 in cell #2, or that the UE 120 is outside the service area of ​​the service of interest to the UE 120. It is noted that the UE may be pre-configured with information of the service area of ​​the broadcast service using a service announcement which may be in the form of NAS signaling.

[0061] In step 502, the UE detects that MBS is started in cell #2. MBS is used as an example, and the transmission of interest from cell #2 may be any transmission, such as unicast, multicast, or broadcast. As an alternative to detecting that the MBS service is started in cell #2, in an embodiment, the UE 120 may reselect a cell (e.g., cell #3) that broadcasts the service of interest to the UE 120, or the UE 120 becomes interested in the service provided in cell #2.

[0062] In step 504, UE 120 reads the transmission schedule (e.g., in SIB20) of cell #2 (or cell #3 in the case that the UE reselects cell #3 in step 502). The reading of SIB20 may be done during the gap from cell #1. In another example, the reading of SIB20 and possibly at least one MCCH may be done by leaving the RRC connection in cell #1. Based on the obtained transmission schedule, UE 120 becomes aware of the requirements needed for UE 120 to receive services from cell #2 (or cell #3).

[0063] Based on the knowledge of the transmission schedule of the transmission of interest for cell #2, UE 120 determines in step 506 that the MCCH (and / or MTCH, if MCCH is monitored) for the broadcast service from cell #2 cannot be monitored in step 508 due to the maximum gap duration limit (e.g., DRX on duration of G-RNTI>maximum gap duration and / or MCCH monitoring window is higher than the maximum gap duration). Figure 2 As shown, step 508 of including the broadcasted MCCH may include a message being sent repeatedly.

[0064] In the embodiment ( Figure 5AIn the example shown in FIG. 1 , the UE monitors SIB20 and detects that MCCH can be intercepted. However, based on the reception of MCCH, the UE may determine that the MTCH of interest cannot be properly received within the available gap. In such a case, the UE needs to request a modification of the transmission scheduling of the MTCH from the second cell.

[0065] In an option ( Figure 5A In the first option 1) of , in step 510, UE 120 may transmit to cell #1 a gap request to request a gap that may have a maximum possible length (e.g., 20 ms). In an embodiment, where UE 120 is a MUSIM UE, MUSIM periodic or aperiodic gaps are available for any operation required by other USIMs of the UE (including MBS-related uses). UE 120 may then receive a gap configuration from cell #1. In an embodiment, the gap is a single aperiodic gap. In step 512, it is assumed that UE 120 is in a gap period from cell #1.

[0066] In another option shown with steps 514 to 516 and labeled as Option 2, as steps 510 to 512 (in Figure 5A As an alternative to the above (marked as option 1 in FIG), assuming that the MCCH cannot be received within the gap duration, the UE 120 decides to leave its RRC connection with cell #1 to utilize the full MCCH window of cell #2 (or cell #3). In this case, since the UE 120 will return to cell #1 after the MCCH window of cell #2 ends, it is beneficial not to move to RRC_IDLE with respect to cell #1, but to enter an RRC inactive state that allows the UE to quickly return to cell #1. To achieve this, the UE 120 may send UE assistance information (UEAssistanceInformation) for RRC departure with a preference for moving to RRC inactive in step 514. For example, when subsequent steps 518 to 522 cannot be completed within the maximum gap duration of cell #1, entering RRC inactive (or even RRC idle) with respect to cell #1 may be used. As described above, if the UE is moved to RRC inactive, the UE 120 may beneficially apply RRC recovery to quickly resume in the RRC connection with cell #1.

[0067] UE 120 may connect to the second cell #2 in step 518, after which the UE may make an RRC connection with cell #2 in step 520. Note that when UE 120 is in the gap as shown in step 512, or when UE 120 has released the RRC connection from cell 1 as in steps 514 and 516, UE 120 may establish an RRC connection with cell #2 in steps 518 / 520 (if the gap time permits). That is, both options 1 and 2 may include a connection with cell #2 in steps 518 / 520 while it is still RRC_CONNECTED in cell #1 (option 1, in the gap) or RRC_INACTIVE in cell #1 (option 2).

[0068] That is, in one embodiment, UE 120 may establish a connection with the second cell in step 518, and leave the second cell in a gap of cell #1 in step 524 without leaving the RRC connected state with cell #1. In another embodiment, the gap period is not considered to be long enough, in which case the UE may leave cell #1, establish a connection with cell #2 (steps 518-520), and then leave the second cell in step 524 and resume (if the UE is RRC inactive with respect to cell #1) or re-establish a connection with the first cell #1 (if the UE is RRC idle with respect to cell #1). In another embodiment, the UE may utilize small data transmission without entering the RRC connected state with cell #2 (i.e., without performing steps 518, 520, and 524), as will be described later.

[0069] In an embodiment, after a configured time, e.g., after it has requested to leave the RRC connection in cell #1, if an RRC release message has not been received from cell #1, UE 120 leaves the RRC connection of cell #1 and moves autonomously to RRC idle. In yet another embodiment, UE 120 is moved to RRC inactive (e.g., RRC release with suspension configuration) by gNB 110 in response to the UE requesting to release the RRC connection and preferring to move to RRC inactive. Note that (not shown in FIG. 5 ) cell #1 may decide to release the UE RRC connection without suspending the configuration.

[0070] In step 522, UE 120 sends information of the limitation of the maximum gap duration to cell #2 (or cell #3 if it is the cell to which the UE is connected in the previous step). This information may be signaled together with the multicast interest indication (MII) defined in Rel-17, which includes information of the services that the UE is interested in. The information may include, for example, the maximum gap duration that UE 120 may have from another operator / cell #1 and / or the maximum MCCH monitoring window / DRX on duration that UE 120 may tolerate from cell #2.

[0071] As shown above, in an embodiment, step 522 can be performed by using SDT while maintaining connection to cell #1 and not entering the RRC connected state with respect to cell #2. In another embodiment, step 522 may be performed after connecting to the second cell #2 while maintaining connection to cell #1 or after releasing the connection to cell #1.

[0072] In step 524, after sending the modification request in step 522, UE 120 may release the connection to cell #2 to enter RRC idle or inactive state with respect to cell #2. Thus, UE 120 temporarily enters an RRC connected state with respect to the second cell #2, and transmits information to the second cell #2 in the RRC connected state. Here, in an embodiment, UE-initiated RRC release may be used. Step 524 may also include if the UE leaves the RRC connection in cell #1, the UE reestablishing or resuming the previous connection with cell #1.

[0073] Steps 526, 528, and 530 illustrate some non-limiting embodiments of how gNB 112 may then modify the transmission schedule to enable UE 120 in cell #2 to monitor the service of interest (e.g., MBS) from cell #2 within the gap configuration of cell #1. That is, based on the information received in step 522 (possibly sent by multiple UEs in cell #2), optimization may be performed at cell #2 so that UEs interested in the transmitted broadcast service will be able to receive the service of interest. gNB 112 may perform one or more of steps 526, 528, and 530.

[0074] In the options of step 526, if gNB 112 has configured a MCCH transmission window and / or DRX on period that is larger than the indicated maximum gap for cell #1, these may be set to smaller values ​​appropriate to the UE limitations. Figure 7This embodiment may become relevant because typically the above transmission period may be set by the corresponding gNB 112 to a larger value in order to be flexible, e.g., the MCCH may be transmitted at a time deemed appropriate by the gNB based on the load in the cell within the MCCH transmission window.

[0075] By reducing the duration, this flexibility may be compromised with the advantage that more UEs can receive the service of interest from cell #2. However, if gNB 112 is not willing to compromise this flexibility so much that it will satisfy the needs of UE 120, then as an alternative, the MCCH repetition period may be shortened, such as Figure 8 As shown in , it is still possible to configure the MCCH window duration to be smaller (even though it still does not completely fit within the gap period).

[0076] exist Figure 5B In the options of step 528, Fig. 9 As shown, the gNB 112 may segment the MCCH information into several fragments and transmit the relevant portion for such UE within a feasible transmission window duration. Subsequently, the (multiple) portions of the MCCH information of interest to the UE, such as scheduling information for broadcast services of interest to the UE marked with blocks with horizontal lines within the MCCH, will be transmitted using a configuration suitable for the maximum gap of the UE. This may allow UEs with limitations to receive the relevant portion of the message. Other services of no interest marked with blocks with dots may be transmitted even in locations where they cannot be received by the UE 120. In this case, SIB20 may be enhanced such that different transmission schedules (e.g., MCCH scheduling information) should be provided to each of the different blocks of the segmented MCCH. In an embodiment, other information of the MCCH (e.g., scheduling information for other broadcast services) remains unchanged.

[0077] In an option of step 530, gNB 112 rearranges the content of the transmission from cell #2 so that the predetermined type of content is transmitted at the beginning of the transmission window. For example, assume that the length of the MCCH is 40ms. Based on this rearrangement, the most important data (based on a predetermined criterion) is transmitted at the beginning of the MCCH so that a UE 120 with, for example, a 20ms gap can receive the first half of the MCCH. This Fig.10, where blocks with dots and horizontal lines within the MCCH block represent predetermined content that is deemed important for UE reception. As shown, these blocks with dots and horizontal lines are rearranged to appear in the first half of the MCCH block within the configured gap suitable for cell #1. As another example, if the UE's broadcast data is scheduled, say, 30ms later (40ms away), the gNB 112 may again adjust the transmission schedule to bring it to the front (within 20ms) and resend the change in SIB20 accordingly.

[0078] In steps 532 and / or 534, gNB 112 then transmits the modified transmission schedule to UE cell #2. For example, this may be done using SIB20 and / or MCCH, depending on which transmission (MCCH and / or MTCH) is adjusted. UE 120 may detect that information during the requested gap (which may be a single aperiodic gap) of cell #1 or while connected to cell #2.

[0079] As shown above, Figure 5A Option 1 shown includes an embodiment in which a connection to a second cell #2 is not required. In this embodiment, the steps requiring UE 120 to disconnect from cell #1 and connect to cell #2 are not required (i.e., steps 514-520 and 524 can be omitted). In this embodiment, if UE 120 is in an RRC inactive (or RRC idle) state with cell #2 during gap 512, UE 120 does not have to establish an RRC connection with cell #2 to transmit information about its restrictions. Instead, UE 120 can beneficially apply a small data transmission (SDT) to send the information as an SDT payload because the information is expected to fit into the allowed payload size for SDT. This can include UE 120 using a random access procedure in which message 3 or message A in a 4-step or 2-step random access procedure can carry the SDT. In this option, the transmission of the restrictions of step 522 can be performed during the gap period mentioned in step 512.

[0080] UE 120 may then determine, based on receipt of the modified transmission schedule, that the transmission of interest (e.g., MBS) from cell #2 is able to be received within the limits set by the gap configuration of cell #1. This may be enabled, for example, because the MCCH monitoring window or MTCH is now appropriate for the possible gaps that UE 120 may request from cell #1 (e.g., the configured maximum gap duration). Accordingly, in step 536 UE 120 may request a gap based on the new MBS configuration and receive a corresponding configuration from cell #1 (i.e., if UE 120 has not received a suitable gap configuration from gNB 110 at this time). In step 538, UE 120 may receive MBS from cell #2 while maintaining an RRC connection to cell #1.

[0081] Figure 5A and Figure 5B The solution may provide several advantages. For example, a UE with hardware or software limitations to simultaneously receive both unicast and MBS broadcast from different cells of the same or different networks / operators may request a modification of the broadcast transmission so that the network may optimize the broadcast configuration to accommodate the limitations of the UE.

[0082] Another solution to the problem in question is presented in Figure 6 Steps 600 to 608 are the same as steps 500 to 508. However, Figure 6 In an embodiment of the present invention, MBS-specific gaps are introduced so that in step 610, UE 120 can request such a larger gap from cell #1 to receive broadcasts from cell #2 during the gap duration. To this end, the assistance information (e.g., the request to cell #1 of step 610) can be enhanced to also include reasons, such as broadcast reception from other cells in addition to the requested gap duration. In step 612, the UE is in the gap duration from cell #1. In this assumed larger gap, the UE 120 can request such a larger gap from cell #1 to receive broadcasts from cell #2 during the gap duration. Figure 5A / Figure 5B During a gap that is longer than the default gap allocated to the UE in the embodiment of FIG. 6 , UE 120 is able to receive the broadcast transmission from cell #2 in step 614 .

[0083] Figure 6 This embodiment may allow a UE with HW / SW limitations, receiving unicast and MBS broadcast simultaneously from different cells of the same or different networks / operators, to request a larger gap duration from an RRC connected state cell in order to receive broadcast services from another cell in RRC idle / inactive mode.

[0084] In Figure 5 and Figure 6 In FIG. 1 , it is assumed that MCCH cannot be received by UE 120 within the allocated gap from cell #1. However, MCCH is only an example, and it may be, for example, MTCH reception that is problematic, or some other type of transmission whose transmission scheduling therefore needs to be adjusted ( Figure 5A / 5B) or why a longer gap is needed ( Figure 6 ).

[0085] like Fig.11As shown, an embodiment provides a device 10, which includes a control circuit system (CTRL) 12 (such as at least one processor) and at least one memory 14 storing instructions, which when executed by at least one processor causes the device to at least implement any one of the above processes. In an example, at least one memory and computer program code (software) are configured to enable the device to implement any one of the above processes together with at least one processor. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory may include a database for storing data.

[0086] In an embodiment, the device 10 may include a terminal device of a communication system, such as a user terminal (UT), a computer (PC), a laptop computer, a tablet computer, a cellular phone, a mobile phone, a communicator, a smart phone, a palm computer, a mobile transportation device (such as a car), a household appliance, or any other communication device generally referred to as a UE in the specification. Alternatively, the device is included in such a terminal device. In addition, the device may be or include a module (attached to the UE) that provides connectivity, such as a plug-in unit, a "USB adapter", or any other type of unit. The unit may be installed inside the UE or attached to the UE using a connector or even wirelessly.

[0087] In an embodiment, the apparatus 10 is or is included in the UE 120. The apparatus may be enabled to perform some of the designed functions of the above process, such as Figure 3 steps.

[0088] The apparatus may also include a radio interface (TRX) 16, which includes hardware and / or software for implementing communication connectivity according to one or more communication protocols. For example, the TRX may provide the apparatus with communication capabilities to access a radio access network.

[0089] The apparatus may further comprise a user interface 18 comprising, for example, at least one keypad, microphone, touch display, display, speaker etc. The user interface may be used for controlling the apparatus by a user.

[0090] According to any embodiment, the control circuit system 12 may include a communication control circuit system 20 for determining what the desired transmission schedule for transmissions from the second cell is, and for requesting modifications to the transmission schedule as needed. According to any embodiment, the control circuit system 12 may also include a gap determination circuit system 22 for determining a configured gap for the first cell, and for determining whether the transmissions of the second cell can be received during the gap period of the first cell.

[0091] like Fig.12 As shown, an embodiment provides a device 50, which includes a control circuit system (CTRL) 52, such as at least one processor and at least one memory 54 storing instructions, which when executed by at least one processor causes the device to at least implement any one of the above processes. In an example, at least one memory and computer program code (software) are configured to enable the device to implement any one of the above processes together with at least one processor. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory may include a database for storing data.

[0092] In an embodiment, the apparatus 50 may be or be included in a network node, such as a gNB / gNB-CU / gNB-DU of 5G. In an embodiment, the apparatus is or is included in a network node 110. The apparatus may be enabled to perform some functions of the above process, such as Figure 4 steps.

[0093] In an embodiment, a CU-DU (central unit-distributed unit) architecture is implemented. In this case, the device 50 may be included in a central unit (e.g., a control unit, an edge cloud server, a server), which is operatively coupled (e.g., via a wireless or wired network) to a distributed unit (e.g., a remote radio head / node). That is, the central unit (e.g., an edge cloud server) and the radio node may be independent devices that communicate with each other via a radio path or via a wired connection. Alternatively, they may be in the same entity that communicates via a wired connection, etc. The edge cloud or edge cloud server may serve multiple radio nodes or radio access networks. In an embodiment, at least some of the processes described may be performed by a central unit. In another embodiment, the device may alternatively be included in a distributed unit, and at least some of the processes described may be performed by a distributed unit. In an embodiment, the execution of at least some of the functions of the device 50 may be shared between two physically separate devices (DU and CU) that form one operating entity. Therefore, the device may be seen to depict an operating entity that includes one or more physically separate devices for performing at least some of the described processes. In an embodiment, the apparatus controls the execution of these processes regardless of the location of the apparatus and regardless of where the processes / functions are implemented.

[0094] The device may also include a communication interface (TRX) 56, which includes hardware and / or software for implementing communication connectivity according to one or more communication protocols. For example, the TRX may provide the device with communication capabilities to access a radio access network. The device may also include a user interface 58, which includes, for example, at least one keypad, microphone, touch display, display, speaker, etc. The user interface may be used to control the device by a user.

[0095] According to any embodiment, the control circuit system 52 may include a transmission scheduling circuit system 60, which is used to determine and possibly modify the transmission schedule of the device's transmissions. According to any embodiment, the control circuit system 52 may include, for example, a multicast broadcast service (MBS) circuit system 62, which is used to provide broadcast services in a cell.

[0096] In an embodiment, a device for implementing at least some of the described embodiments comprises at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to implement the functions according to any one of the described embodiments. According to one aspect, when the at least one processor executes the computer program code, the computer program code causes the device to implement the functions according to any one of the described embodiments. According to another embodiment, the device for implementing at least some of the embodiments comprises at least one processor and at least one memory containing computer program code, wherein the at least one processor and the computer program code perform at least some of the functions according to any one of the described embodiments. Thus, at least one processor, memory and computer program code form a processing unit for implementing at least some of the described embodiments. According to yet another embodiment, the device for implementing at least some of the embodiments comprises a circuit system comprising at least one processor and at least one memory containing computer program code. When activated, the circuit system causes the device to perform at least some of the functions according to any one of the described embodiments.

[0097] As used in this application, the term 'circuitry' refers to all of the following: (a) hardware-only circuit implementations, such as implementations in analog and / or digital circuits only, and (b) combinations of circuitry and software (and / or firmware), such as (if applicable): (i) a combination of (multiple) processors or (ii) portions of (multiple) processors / software, including (multiple) digital signal processors, software, and (multiple) memory storage, which work together to enable the device to perform various functions, and (c) circuitry, such as a microprocessor (or multiple microprocessors) or a portion of a microprocessor (or multiple microprocessors), which requires software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuitry" applies to all uses of the term in this application. As a further example, as used in this application, the term 'circuitry' would also cover an implementation of only a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. For example, and if applicable to the particular element, the term 'circuitry' also covers a baseband integrated circuit or an application processor integrated circuit for a mobile phone or a similar integrated circuit within a server, a cellular network device, or another network device.

[0098] In an embodiment, at least some of the described processes may be performed by an apparatus including corresponding components for implementing at least some of the described processes. Some example components for implementing the processes may include at least one of the following: a detector, a processor (including dual-core and multi-core processors), a digital signal processor, a controller, a receiver, a transmitter, an encoder, a decoder, a memory, a RAM, a ROM, software, firmware, a display, a user interface, a display circuit system, a user interface circuit system, a user interface software, a display software, a circuit, an antenna, an antenna circuit system, and a circuit system.

[0099] As used herein, the term non-transitory is a limitation of the medium itself (ie, tangible, not a signal), not a limitation on the persistence of data storage (eg, RAM versus ROM).

[0100] As used herein, the term "means" should be interpreted as being in the singular, i.e., referring to a single element, or in the plural, i.e., referring to a combination of single elements. Thus, the term "means for [performing A, B, C]" should be interpreted as covering an apparatus in which there is only one means for performing A, B, and C, or in which there are separate means for performing A, B, and C, or partially or completely overlapping means for performing A, B, and C. Additionally, the term "means for performing A, means for performing B, means for performing C" should be interpreted as covering an apparatus in which there is only one means for performing A, B, and C, or in which there are separate means for performing A, B, and C, or partially or completely overlapping means for performing A, B, and C.

[0101] The techniques and methods described herein can be implemented in various ways. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For hardware implementations, one or more devices of the embodiments can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be implemented by a module of at least one chip set (e.g., process, function, etc.) that performs the methods described herein. The software code can be stored in a memory unit and executed by a processor. The memory unit can be implemented inside a processor or outside a processor. In the latter case, it can be communicatively coupled to the processor via different components, as known in the art. Additionally, the components of the system described herein can be rearranged and / or supplemented by additional components to support the implementation of various aspects of its description, etc., and they are not limited to the precise configurations set forth in the given figures, as will be understood by those skilled in the art.

[0102] The described embodiments may also be performed in the form of a computer process defined by a computer program or a portion thereof. The described method embodiments may be performed by executing at least a portion of a computer program including corresponding instructions. The computer program may be in source code form, object code form, or some intermediate form, and it may be stored in a carrier, which may be any entity or device capable of carrying the program. For example, the computer program may be stored on a computer program distribution medium readable by a computer or processor. The computer program medium may be, for example, but not limited to, a recording medium, a computer memory, a read-only memory, an electrical carrier signal, a telecommunication signal, and a software distribution package. The computer program medium may be a non-transient medium. The coding of the software for implementing the embodiments shown and described is fully within the scope of those of ordinary skill in the art.

[0103] The following is a list of some aspects of the invention.

[0104] According to a first aspect, a method at a device is provided, comprising: receiving information of a transmission schedule from a second cell, wherein the device is capable of receiving from one cell at a time; determining, based on the received transmission schedule, that transmissions from the second cell cannot be received within restrictions set by a gap configuration of the first cell, wherein the device is in a radio resource control (RRC) connected state relative to the first cell; transmitting to the second cell an indication that transmissions from the second cell cannot be received based on the transmission schedule; and receiving information of a modified transmission schedule from the second cell.

[0105] Various embodiments of the first aspect may include at least one feature from the following bulleted list: Wherein, when the device is in an RRC idle state or in an RRC inactive state relative to the second cell, the information of the transmission schedule is received via a broadcast transmission from the second cell. Wherein, information of the transmission schedule is included in at least one of the system information block 20 or the MPS control channel. wherein the transmission schedule indicates a schedule of a broadcast transmission and includes at least one of a periodicity, a transmission length, or a modified length of control channel information of the transmitted broadcast transmission. • wherein the gap configuration indicates a scheduling gap for the first cell, the apparatus being able to monitor transmissions of another cell during the scheduling gap. Wherein determining that the transmission from the second cell cannot be received within the limits set by the gap configuration of the first cell comprises: determining that a transmission monitoring window for the transmission of the second cell is greater than a maximum available gap of the first cell. The receiving triggering means of the transmission scheduling information: requests a gap configuration from the first cell, and based on the request for the gap configuration, receives the gap configuration from the first cell. The sending of the indication to the second cell comprises: including the indication in a small data transmission during a gap of the first cell without establishing an RRC connection with the second cell. ·Wherein, reception of the transmission scheduled information triggers: requesting from the first cell to leave the RRC connection in the first cell, and receiving an RRC release message from the first cell, wherein the request includes a preference for moving to an RRC_IDLE or RRC_INACTIVE state after leaving the RRC connection in the first cell; and one of the following: receiving the RRC release message from the first cell, or, after waiting for a predetermined time, moving to RRC idle in the first cell without receiving an RRC release message from the first cell. wherein transmitting the indication to the second cell comprises temporarily entering an RRC CONNECTED state with respect to the second cell; and transmitting the indication in the RRC CONNECTED state. wherein, when entering the RRC connected state with respect to the second cell, entering the RRC inactive state or the RRC idle state with respect to the first cell; and after the device has transmitted the indication to the second cell, resuming or re-establishing the RRC connected state with respect to the first cell. wherein the entering of the RRC connected state with respect to the second cell occurs within a gap in the first cell without leaving the RRC connected state with respect to the first cell. Wherein, transmitting the indication to the second cell comprises transmitting information of an available gap configuration of the first cell. wherein transmitting the indication to the second cell comprises transmitting at least one of a maximum gap duration that the apparatus can request from the first cell or a maximum transmission monitoring window that the apparatus can tolerate from the second cell, and wherein the modification of the transmission schedule is based on the gap configuration of the first cell or the maximum transmission monitoring window that the apparatus can tolerate from the second cell. • Wherein the apparatus comprises a Multiple Subscriber Identity Module (MUSIM). Wherein the device is a user equipment.

[0106] According to a second aspect, a method at a device is provided, comprising: broadcasting a transmission schedule of a second cell; receiving an indication from a user equipment in the second cell that transmission of the second cell cannot be received based on a current transmission schedule, wherein the user equipment is capable of receiving from one cell at a time; modifying the transmission schedule based on the received indication; and broadcasting the modified transmission schedule of the second cell.

[0107] Various embodiments of the second aspect may include at least one feature from the following bulleted list: Wherein, information of the transmission schedule is transmitted via broadcast transmission. Wherein, information of the transmission schedule is included in at least one of the system information block 20 or the MPS control channel. · wherein the transmission schedule indicates a broadcast transmission schedule of the second cell and includes at least one of a periodicity, a transmission length, or a modified length of control channel information of the transmitted broadcast transmission. • wherein the indication comprises information of a gap configuration of the first cell, wherein the gap configuration defines a scheduling gap of the first cell, during which the user equipment can monitor transmission of another cell. • Wherein the indication includes information of at least one of: a maximum gap duration that the user equipment can request from the first cell or a maximum transmission monitoring window that the user equipment can tolerate from the second cell. • wherein modifying the transmission schedule based on the received indication comprises: reducing a maximum transmission monitoring window associated with transmissions of the transmission schedule. • wherein modifying the transmission schedule based on the received indication comprises increasing a repetition frequency associated with transmissions of the transmission schedule. • wherein modifying the transmission schedule based on the received indication comprises segmenting transmissions of the transmission schedule. • wherein transmitting the modified transmission schedule for the second cell comprises transmitting a different transmission schedule for a different segment of the transmission. Wherein modifying the transmission schedule based on the received indication comprises: rearranging the content of the transmission of the transmission schedule so that the predetermined type of content is transmitted at the beginning of the corresponding transmission window. • receiving a plurality of indications from a plurality of user equipments; and modifying a transmission schedule based on the received plurality of indications.

[0108] According to a third aspect, there is provided an apparatus comprising: at least one processor; and at least one memory storing instructions, which when executed by the at least one processor causes the apparatus to at least: receive information of a transmission schedule from a second cell, wherein the apparatus is capable of receiving from one cell at a time; based on the received transmission schedule, determine that transmissions from the second cell cannot be received within the limits set by the gap configuration of the first cell, wherein the apparatus is in a radio resource control (RRC) connected state relative to the first cell; transmit to the second cell an indication that transmissions from the second cell cannot be received based on the transmission schedule; and receive information of a modified transmission schedule from the second cell. Various embodiments of the third aspect may include at least one feature from the bulleted list under the first aspect.

[0109] According to a fourth aspect, there is provided an apparatus, comprising: at least one processor; and at least one memory storing instructions, which when executed by the at least one processor causes the apparatus to at least: broadcast a transmission schedule of a second cell; receive an indication from a user equipment in the second cell that a transmission of the second cell cannot be received based on a current transmission schedule, wherein the user equipment is capable of receiving from one cell at a time; modify the transmission schedule based on the received indication; and broadcast the modified transmission schedule of the second cell. Different embodiments of the fourth aspect may include at least one feature in the bulleted list under the second aspect.

[0110] According to a fifth aspect, there is provided a computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when loaded into an apparatus, execute the method according to the first aspect.

[0111] According to a sixth aspect, there is provided a computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when loaded into an apparatus, execute the method according to the second aspect.

[0112] According to a seventh aspect, there is provided a computer program product, the computer program product comprising program instructions, which, when loaded into a device, execute the method according to the first aspect.

[0113] According to an eighth aspect, there is provided a computer program product, the computer program product comprising program instructions, which, when loaded into a device, execute the method according to the second aspect.

[0114] According to a ninth aspect, there is provided an apparatus comprising components for performing the method according to the first aspect and / or components configured to cause the apparatus to perform the method according to the first aspect.

[0115] According to a tenth aspect, there is provided an apparatus comprising components for performing the method according to the second aspect and / or components configured to cause the apparatus to perform the method according to the second aspect.

[0116] According to the eleventh aspect, a computer-implemented system is provided, comprising: a server and at least one radio node; and at least one processor and at least one memory storing instructions, wherein when the instructions are executed by at least one processor, the system implements at least the method according to the first aspect and / or the method according to the second aspect.

[0117] According to the twelfth aspect, a computer-implemented system is provided, comprising: one or more processors; at least one data storage device; and one or more computer program instructions associated with at least one data storage to be executed by the one or more processors, which are used to perform the method according to the first aspect and / or the method according to the second aspect.

[0118] Although the present invention has been described above with reference to the examples according to the accompanying drawings, it is obvious that the present invention is not limited thereto, but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate rather than limit the embodiment. It is obvious to those skilled in the art that, as technology advances, the concept of the present invention can be implemented in various ways. In addition, it is clear to those skilled in the art that the described embodiments can (but are not required to) be combined with other embodiments in various ways.

Claims

1. A device comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receiving information on a transmission schedule from a second cell, wherein the apparatus is capable of receiving from one cell at a time; determining, based on the received transmission schedule, that transmissions from the second cell cannot be received within constraints set by a gap configuration of a first cell, wherein the apparatus is in a radio resource control (RRC) connected state with respect to the first cell; transmitting to the second cell an indication that the transmission from the second cell cannot be received based on the transmission schedule; as well as Information of a modified transmission schedule is received from the second cell.

2. The apparatus according to claim 1, wherein when the apparatus is in an RRC idle state or in an RRC inactive state relative to the second cell, the information of the transmission schedule is received via a broadcast transmission from the second campus.

3. The apparatus according to any one of claims 1 to 2, wherein the information of the transmission schedule is included in at least one of a system information block 20 or a multicast broadcast service control channel.

4. The apparatus according to any one of claims 1 to 3, wherein the transmission schedule indicates a schedule of a broadcast transmission and includes at least one of a periodicity, a transmission length, or a modified length of control channel information of the broadcast transmission transmitted.

5. The apparatus according to any one of claims 1 to 4, wherein the gap configuration indicates a scheduling gap for the first cell, the apparatus being capable of monitoring transmission of another cell during the scheduling gap.

6. The apparatus of any one of claims 1 to 5, wherein determining that the transmission from the second cell cannot be received within the limits set by the gap configuration of the first cell comprises: A transmission monitoring window for the transmission of the second cell is determined to be greater than a maximum available gap of the first cell.

7. The apparatus according to any one of claims 1 to 6, wherein the reception of the information of the transmission schedule triggers the apparatus: requesting the gap configuration from the first cell, and Based on requesting the gap configuration, the gap configuration is received from the first cell.

8. The apparatus according to any one of claims 1 to 7, wherein transmitting the indication to the second cell comprises: The indication is included in a small data transmission during a gap of the first cell without establishing an RRC connection with the second cell.

9. The apparatus according to any one of claims 1 to 6, wherein the reception of the information of the transmission schedule triggers the apparatus to: requesting, from the first cell, to leave the RRC connection in the first cell, and receiving an RRC release message from the first cell, wherein the request includes a preference to move to an RRC_IDLE or RRC_INACTIVE state after leaving the RRC connection in the first cell; and one of: receiving the RRC release message from the first cell, or After waiting for a predetermined time, without receiving the RRC release message from the first cell, moving to the RRC idle in the first cell.

10. The apparatus according to any one of claims 1 to 7 or claim 9, wherein transmitting the indication to the second cell comprises temporarily entering an RRC connected state with respect to the second cell; and transmitting the indication in the RRC connected state.

11. The apparatus of claim 10, wherein when entering the RRC connected state with respect to the second cell, entering an RRC inactive state or an RRC idle state with respect to the first cell; and after the apparatus has transmitted the indication to the second cell, restoring or re-establishing the RRC connected state with respect to the first cell.

12. The apparatus of claim 10, wherein entering the RRC connected state with respect to the second cell occurs within a gap in the first cell without leaving the RRC connected state with respect to the first cell.

13. The apparatus according to any one of claims 1 to 12, wherein transmitting the indication to the second cell comprises transmitting information of the available gap configuration of the first cell.

14. An apparatus according to any one of claims 1 to 13, wherein transmitting the indication to the second cell comprises transmitting at least one of the following: the maximum gap duration that the apparatus can request from the first cell or the maximum transmission monitoring window that the apparatus can tolerate from the second cell, and wherein the modification of the transmission scheduling is based on the gap configuration of the first cell or the maximum transmission monitoring window that the apparatus can tolerate from the second cell.

15. The apparatus of any one of claims 1 to 14, wherein the apparatus comprises a Multiple Subscriber Identity Module (MUSIM).

16. The apparatus according to any one of claims 1 to 15, wherein the apparatus is a user equipment.

17. An apparatus comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: broadcasting a transmission schedule for the second cell; receiving from a user equipment in the second cell an indication that a transmission of the second cell cannot be received based on the current transmission schedule, wherein the user equipment is capable of receiving from one cell at a time; modifying the transmission schedule based on the received indication; and A modified transmission schedule for the second cell is broadcast.

18. The apparatus of claim 17, wherein the information of the transmission schedule is transmitted via a broadcast transmission.

19. The apparatus according to any one of claims 17 to 18, wherein the information of the transmission schedule is included in at least one of a system information block 20 or a multicast broadcast service control channel.

20. The apparatus according to any one of claims 17 to 19, wherein the transmission schedule indicates a broadcast transmission schedule of the second cell and includes at least one of a periodicity, a transmission length, or a modified length of control channel information of the transmitted broadcast transmission.

21. The apparatus according to any one of claims 17 to 20, wherein the indication comprises information of the gap configuration of the first cell, wherein the gap configuration defines a scheduling gap of the first cell, and the user equipment can monitor transmission of another cell during the scheduling gap.

22. The apparatus according to any one of claims 17 to 21, wherein the indication comprises at least one of the following information: a maximum gap duration that the user equipment can request from the first cell or a maximum transmission monitoring window that the user equipment can tolerate from the second cell.

23. The apparatus of any one of claims 17 to 22, wherein modifying the transmission schedule based on the received indication comprises reducing the maximum transmission monitoring window associated with the transmission of the transmission schedule.

24. The apparatus of any one of claims 17 to 23, wherein modifying the transmission schedule based on the received indication comprises increasing a repetition frequency associated with the transmissions of the transmission schedule.

25. The apparatus of any one of claims 17 to 24, wherein modifying the transmission schedule based on the received indication comprises segmenting the transmissions of the transmission schedule.

26. The apparatus of claim 25, wherein transmitting the modified transmission schedule for the second cell comprises transmitting different transmission schedules for different segments of the transmission.

27. An apparatus according to any one of claims 17 to 26, wherein modifying the transmission schedule based on the received indication comprises rearranging the content of the transmission of the transmission schedule so that content of a predetermined type is transmitted at the beginning of a corresponding transmission window.

28. An apparatus according to any one of claims 17 to 27, wherein the apparatus is further caused to receive a plurality of indications from a plurality of user equipments; and modify the transmission schedule based on the received plurality of indications.

29. A method at a user equipment, comprising: receiving transmission scheduling information from the second cell, wherein the user equipment is capable of receiving from one cell at a time; determining, based on the received transmission schedule, that transmissions from the second cell cannot be received within restrictions set by a gap configuration of the first cell, wherein the apparatus is in a radio resource control (RRC) connected state with respect to the first cell; transmitting, based on the transmission schedule, to the second cell, an indication that the transmission from the second cell cannot be received; as well as Information of a modified transmission schedule is received from the second cell.

30. A method at a network node, comprising: broadcasting a transmission schedule for the second cell; receiving, in the second cell, from a user equipment, an indication that a transmission of the second cell cannot be received based on the current transmission scheduling, wherein the user equipment is capable of receiving from one cell at a time; modifying the transmission schedule based on the received indication; and A modified transmission schedule for the second cell is broadcast.

31. A computer program product, embodied on a distribution medium readable by a computer and comprising program instructions, which, when the program is executed by a device, cause the device to implement the method according to any one of claims 29 or 30.

32. A computer program product comprising program instructions, which, when the program is executed by a device, cause the device to implement the method according to any one of claims 29 or 30.

33. An apparatus comprising means for performing the method according to any one of claims 29 or 30.

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