WO2021175443A1 - Prévention de perte de paquets dans des transmissions point à multipoint - Google Patents

Prévention de perte de paquets dans des transmissions point à multipoint Download PDF

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Publication number
WO2021175443A1
WO2021175443A1 PCT/EP2020/056056 EP2020056056W WO2021175443A1 WO 2021175443 A1 WO2021175443 A1 WO 2021175443A1 EP 2020056056 W EP2020056056 W EP 2020056056W WO 2021175443 A1 WO2021175443 A1 WO 2021175443A1
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WO
WIPO (PCT)
Prior art keywords
point
cell
point transmission
terminal device
transmission
Prior art date
Application number
PCT/EP2020/056056
Other languages
English (en)
Inventor
David NAVRÁTIL
Bernhard Wegmann
Fasil BERHANU TESEMA
Volker PAULI
Original Assignee
Nokia Technologies Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Technologies Oy filed Critical Nokia Technologies Oy
Priority to PCT/EP2020/056056 priority Critical patent/WO2021175443A1/fr
Publication of WO2021175443A1 publication Critical patent/WO2021175443A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0091—Signaling for the administration of the divided path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0007—Control or signalling for completing the hand-off for multicast or broadcast services, e.g. MBMS
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0032—Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
    • H04L5/0035—Resource allocation in a cooperative multipoint environment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/0085—Hand-off measurements

Definitions

  • the following exemplary embodiments relate to a cellular communication network and preventing loss of one or more data packets.
  • Cellular communication networks allow terminal devices to be connected to a network and transmit and receive data wirelessly even when a terminal device is moving. When the terminal device moves from the coverage area of one cell to another, it is desirable that there is no discontinuity in transmission or reception of data transmissions.
  • an apparatus comprising means for determining that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determining that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, providing, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determining that the terminal device is to perform mobility from the first cell to the second cell, and transmitting information regarding the second cell to the terminal device.
  • an apparatus comprising means for receiving a first point to multi-point transmission, receiving an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determining that mobility is to be performed to the adjacent cell, and initiating a connection to the access node.
  • an apparatus comprising at least one processor, and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: determine that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determine that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, provide, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determine that the terminal device is to perform mobility from the first cell to the second cell, and transmit information regarding the second cell to the terminal device.
  • an apparatus comprising at least one processor, and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: receive a first point to multi-point transmission, receive an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determine that mobility is to be performed to the adjacent cell, and initiate a connection to the access node.
  • a method comprising determining that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determining that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, providing, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determining that the terminal device is to perform mobility from the first cell to the second cell, and transmitting information regarding the second cell to the terminal device.
  • a method comprising receiving a first point to multi-point transmission, receiving an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determining that mobility is to be performed to the adjacent cell, and initiating a connection to the access node.
  • a computer program product readable by a computer and, when executed by the computer, configured to cause the computer to execute a computer process comprising determining that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determining that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, providing, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determining that the terminal device is to perform mobility from the first cell to the second cell, and transmitting information regarding the second cell to the terminal device.
  • a computer program product readable by a computer and, when executed by the computer, configured to cause the computer to execute a computer process comprising receiving a first point to multi point transmission, receiving an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determining that mobility is to be performed to the adjacent cell, and initiating a connection to the access node.
  • a computer program product comprising computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for performing determining that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determining that the first multi-point transmission and the second multi point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, providing, to a terminal device, an indication regarding the determination that the first multi point transmission and the second multi-point transmission are asynchronous, determining that the terminal device is to perform mobility from the first cell to the second cell, and transmitting information regarding the second cell to the terminal device.
  • a computer program product comprising computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for performing receiving a first point to multi-pointtransmission, receiving an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determining that mobility is to be performed to the adjacent cell, and initiating a connection to the access node.
  • a computer program comprising instructions for causing an apparatus to perform at least the following: determine that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determine that the first multi-pointtransmission and the second multi-pointtransmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, provide, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determine that the terminal device is to perform mobility from the first cell to the second cell, and transmit information regarding the second cell to the terminal device.
  • a computer program comprising instructions for causing an apparatus to perform at least the following: receive a first point to multi-point transmission, receive an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determine that mobility is to be performed to the adjacent cell, and initiate a connection to the access node.
  • a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: determine that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determine that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, provide, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determine that the terminal device is to perform mobility from the first cell to the second cell, and transmit information regarding the second cell to the terminal device.
  • a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receive a first point to multi-point transmission, receive an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determine that mobility is to be performed to the adjacent cell, and initiate a connection to the access node.
  • a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: determine that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, determine that the first multi-point transmission and the second multi point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, provide, to a terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determine that the terminal device is to perform mobility from the first cell to the second cell, and transmit information regarding the second cell to the terminal device.
  • a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receive a first point to multi-point transmission, receive an indication that the first multi-point transmission and a second multi-point transmission provided in an adjacent cell are asynchronous, wherein the indication further comprises a request to establish a connection to an access node before performing mobility, determine that mobility is to be performed to the adjacent cell, and initiate a connection to the access node.
  • a system comprising an access node and a terminal device, the system being caused to: determine, by the access node, that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, receive, by the terminal device, the first point to multi-point transmission, determine, by the access node, that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, provide, by the access node to the terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determine, by the terminal device, that mobility is to be performed from the first cell to the second cell and connect, by the terminal device, to the access node, and transmit, by the access node, information regarding the second cell to the terminal device.
  • a system comprising means for determining, by the access node, that a first point to multi-point transmission is provided in a first cell to transmit data comprised in a service and a second point to multi-point transmission is provided in a second cell to transmit the data comprised in the service, receiving, by the terminal device, the first point to multi-point transmission, determining, by the access node, that the first multi-point transmission and the second multi-point transmission are asynchronous and that the first point to multi-point transmission is slower than the second point to multi-point transmission, providing, by the access node to the terminal device, an indication regarding the determination that the first multi-point transmission and the second multi-point transmission are asynchronous, determining, by the terminal device, that mobility is to be performed from the first cell to the second cell and connecting, by the terminal device, to the access node, and transmitting, by the access node, information regarding the second cell to the terminal device.
  • FIG. 1 illustrates an exemplary embodiment of a radio access network.
  • FIG. 2 illustrates an exemplary embodiment of PTM transmissions in adjacent cells.
  • FIG. 3 illustrates an exemplary embodiment of an access node
  • FIG. 4a, 4b and 4c illustrate signalling according to an exemplary embodiment.
  • FIG. 5a and 5b illustrate exemplary embodiments of a gNB with a split architecture.
  • FIG. 6 and 7 illustrates flow charts according to exemplary embodiments.
  • FIG. 8 and 9 illustrate exemplary embodiments of an apparatus.
  • circuitry refers to all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of circuits and software (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software including digital signal processor(s), software, and memoiy(ies) that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.
  • This definition of ‘circuitry’ applies to all uses of this term in this application.
  • circuitry would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and/or firmware.
  • circuitry would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.
  • the above-described embodiments of the circuitry may also be considered as embodiments that provide means for carrying out the embodiments of the methods or processes described in this document.
  • the techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof.
  • the apparatus(es) of embodiments may be implemented within 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), graphics processing units (GPUs), processors, controllers, micro- controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.
  • ASICs application-specific integrated circuits
  • DSPs digital signal processors
  • DSPDs digital signal processing devices
  • PLDs programmable logic devices
  • FPGAs field programmable gate arrays
  • GPUs graphics processing units
  • processors controllers, micro- controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.
  • the software codes may be stored in a memory unit and executed by processors.
  • the memory unit may be implemented within the processor or externally to the processor. In the latter case, it can be communicatively coupled to the processor via any suitable means.
  • the components of the systems described herein may be rearranged and/or complemented by additional components in order to facilitate the achievements of the various aspects, etc., described with regard thereto, and they are not limited to the precise configurations set forth in the given figures, as will be appreciated by one skilled in the art.
  • Embodiments described herein may be implemented in a communication system, such as in at least one of the following: Global System for Mobile Communications (GSM) or any other second generation cellular communication system, Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, a system based on IEEE 802.11 specifications, a system based on IEEE 802.15 specifications, and/or a fifth generation (5G) mobile or cellular communication system.
  • GSM Global System for Mobile Communications
  • UMTS Universal Mobile Telecommunication System
  • 3G Universal Mobile Telecommunication System
  • W-CDMA basic wideband-code division multiple access
  • HSPA high-speed packet access
  • LTE Long Term Evolution
  • LTE-Advanced Long Term Evolution
  • the embodiments are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.
  • FIG. 1 depicts examples of simplified system architectures showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown.
  • the connections shown in FIG. 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system may comprise also other functions and structures than those shown in FIG. 1.
  • the example of FIG. 1 shows a part of an exemplifying radio access network.
  • FIG. 1 shows terminal devices 100 and 102 configured to be in a wireless connection on one or more communication channels in a cell with an access node (such as (e/g)NodeB) 104 providing the cell.
  • the access node 104 may also be referred to as a node.
  • the physical link from a terminal device to a (e/g)NodeB is called uplink or reverse link and the physical link from the (e/g) NodeB to the terminal device is called downlink or forward link.
  • (e/g)NodeBs or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage. It is to be noted that although one cell is discussed in this exemplary embodiment, for the sake of simplicity of explanation, multiple cells may be provided by one access node in some exemplary embodiments.
  • a communication system may comprise more than one (e/g)NodeB in which case the (e/g)NodeBs may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signalling purposes.
  • the (e/g)NodeB is a computing device configured to control the radio resources of communication system it is coupled to.
  • the (e/g)NodeB may also be referred to as a base station, an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment.
  • the (e/g)NodeB includes or is coupled to transceivers.
  • the antenna unit may comprise a plurality of antennas or antenna elements.
  • the (e/g)NodeB is further connected to core network 110 (CN or next generation core NGC).
  • CN core network 110
  • the counterpart on the CN side may be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW), for providing connectivity of terminal devices (UEs) to external packet data networks, or mobile management entity (MME), etc.
  • S-GW serving gateway
  • P-GW packet data network gateway
  • MME mobile management entity
  • the terminal device (also called UE, user equipment, user terminal, user device, etc.) illustrates one type of an apparatus to which resources on the air interface are allocated and assigned, and thus any feature described herein with a terminal device may be implemented with a corresponding apparatus, such as a relay node.
  • a relay node is a layer 3 relay (self-backhauling relay) towards the base station.
  • a layer 2 relay is another example of such a relay node.
  • Such a relay node may contain a terminal device part and a Distributed Unit (DU) part.
  • a CU centralized unit
  • the terminal device may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), or an embedded SIM, eSIM, including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, and multimedia device.
  • SIM subscriber identification module
  • eSIM embedded SIM
  • a user device may also be an exclusive or a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network.
  • a terminal device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.
  • the terminal device may also utilise cloud.
  • a terminal device may comprise a small portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud.
  • the terminal device (or in some embodiments a layer 3 relay node) is configured to perform one or more of user equipment functionalities.
  • CPS cyber-physical system
  • 1CT devices sensors, actuators, processors microcontrollers, etc.
  • Mobile cyber physical systems in which the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.
  • apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in FIG. 1) may be implemented.
  • 5G enables using multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available.
  • MIMO multiple input - multiple output
  • 5G mobile communications supports a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control.
  • 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also being integratable with existing legacy radio access technologies, such as the LTE.
  • Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage is provided by the LTE and 5G radio interface access comes from small cells by aggregation to the LTE.
  • 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-Rl operability (inter-radio interface operability, such as below 6GHz - cmWave, below 6GHz - cmWave - mmWave).
  • inter-RAT operability such as LTE-5G
  • inter-Rl operability inter-radio interface operability, such as below 6GHz - cmWave, below 6GHz - cmWave - mmWave.
  • One of the concepts considered to be used in 5G networks is network slicing in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.
  • the current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network.
  • the low latency applications and services in 5G may require to bring the content close to the radio which may lead to local break out and multi-access edge computing (MEC).
  • MEC multi-access edge computing
  • 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors.
  • MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time.
  • Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).
  • the communication system is also able to communicate with other networks, such as a public switched telephone network or the Internet 112, and/or utilise services provided by them.
  • the communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in FIG. 1 by “cloud” 114).
  • the communication system may also comprise a central control entity, or a like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.
  • Edge cloud may be brought into radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN).
  • RAN radio access network
  • NFV network function virtualization
  • SDN software defined networking
  • Using edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts.
  • Application of cloudRAN architecture enables RAN real time functions being carried out at the RAN side (in a distributed unit, DU 104) and non-real time functions being carried out in a centralized manner (in a centralized unit, CU 108).
  • 5G may also utilize satellite communication to enhance or complement the coverage of 5G service, for example by providing backhauling.
  • Possible use cases are providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on board of vehicles, or ensuring service availability for critical communications, and future railway/maritime/aeronautical communications.
  • Satellite communication may utilise geostationary earth 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).
  • GEO geostationary earth orbit
  • LEO low earth orbit
  • Each satellite 106 in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells.
  • the on-ground cells may be created through an on-ground relay node 104 or by a gNB located on-ground or in a satellite.
  • the depicted system is an example of a part of a radio access system and the system may comprise a plurality of (e/g)NodeBs, the terminal device may have an access to a plurality of radio cells and the system may comprise also other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the (e/g)NodeBs may be a Home(e/g)nodeB. Additionally, in a geographical area of a radio communication system a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided.
  • Radio cells may be macro cells (or umbrella cells) which are large cells, usually having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells.
  • the (e/g)NodeBs of FIG. 1 may provide any kind of these cells.
  • a cellular radio system may be implemented as a multilayer network including several kinds of cells.
  • one access node provides one kind of a cell or cells, and thus a plurality of (e/g)NodeBs are required to provide such a network structure.
  • a network which is able to use “plug-and-play” (e/g)NodeBs may include, in addition to Home (e/g)NodeBs (H(e/g)nodeBs), a home node B gateway, or HNB-GW (not shown in FIG. 1).
  • HNB-GW HNB Gateway
  • a HNB Gateway (HNB-GW) which may be installed within an operator’s network may aggregate traffic from a large number of HNBs back to a core network.
  • Point to multi-point, PTM, transmission may be understood as a transmission in which an access node transmits the same transmission to multiple terminal devices.
  • Multicast and broadcast may be understood as examples of PTM.
  • LTE-A Long Term Evolution - Advanced
  • eMBMS enhanced Multimedia Broadcast Multicast Service
  • PTM transmissions may be performed using one cell, in other words using a single cell PTM, SC-PTM, or using MBMS over a single frequency network, MBSFN, transmission that utilizes multiple cells, in other words, utilizes a multi-cell PTM, MC-PTM.
  • the SC-PTM may use radio access parameters for unicast and share the same channels whereas MBSFN may use separate radio access parameters and channels.
  • single-cell and multi-cell PTM transmissions may be supported on a common radio access framework with 5G new radio, NR. Such functionality may be called as mixed-mode broadcast.
  • inter-cell-interference control measures As cells that are adjacent to each other transmit the same transmission in a multi-cell transmission, there may not be a need to avoid interference, that may occur near the edge of a cell, using inter-cell-interference control measures. As adjacent cells are used to transmit the same transmission, inter-cell interference may be reduced or, in some exemplary embodiments, even a constructive interface may be achieved.
  • a transmission area may be understood as an area where a service is provided using one or more PTM transmissions.
  • a transmission area may be dynamically configured with various PTM transmissions, such as SC-PTM and/or MC-PTM, within the transmission area. Accordingly, if a service requires data to be transmitted, that may be achieved using various independent SC-PTM and/or MC-PTM transmission schemes.
  • a transmission scheme used may use optimized network settings based on, at least partly, for example distribution of terminal devices within the transmission area. For example, cells that have a large concentration of terminal devices near edges of the cells may utilize MC-PTM and if a cell has high concentration of terminal devices near the centre of the cell, SC-PTM may be utilized.
  • SC-PTM and/or MC-PTM transmissions are independent transmissions, they may use their own optimized network settings such as optimized modulation and coding scheme, MCS, and optimized radio resource scheduling, which takes into account factors such as cell load and multiplexing with other services. Therefore, in some exemplary embodiments, progress of transmissions may vary between the independent SC-PTM and/or MC-PTM transmissions. For example, if there are bursts in the transmission, the variation in progress between the independent transmissions may be considerable.
  • a terminal device that is receiving the transmission is located near an edge of a cell and is to move across the cell boundary, it is beneficial to avoid a situation in which a handover or a cell reselection is performed between adjacent cells, wherein the transmission progress of independent PTM transmissions is not synchronized and may thereby cause the terminal device to experience disturbances, such as packet loss, in the transmission it receives.
  • handover and cell reselection may be both be referred to as mobility.
  • a terminal device may perform mobility at cell boundaries of independent PTM transmissions. If the independent PTM transmissions are asynchronous, then there is a possibility that packet loss occurs.
  • FIG.2 illustrates a situation in which the PTM transmissions in adjacent cells transmit data of the same service, but the transmissions are not synchronized.
  • a service may be understood as providing data to one or more terminal devices. If a plurality of access nodes provides the same service, that may be understood as providing the same data.
  • a first cell 210 provides the same service with a PTM transmission that is the same service as provided by the second cell 220 with another PTM transmission.
  • Terminal devices 212, 214 and 216 are served by the first cell 210.
  • Terminal devices 222 and 224 are served by the second cell 220.
  • the sequence numbering used for data packet in the transmissions are also independent.
  • the terminal device 216 is first served by the first cell 210 and receives the PTM transmission provided by the first cell. The terminal device 216 then moves to an area covered by the second cell 220. Thus, as the terminal device 216 performs mobility, a handover or cell reselection is to be performed and the terminal device 216 is to continue to receive the PTM transmission which is now provided by the second cell 220.
  • the PTM transmissions provided by the cell 210 and 220 are independent, also the network settings used such as MCS setting and scheduler are independent.
  • the last data packet the terminal device 216 received from the first cell 210 had sequence number 4 as illustrated by the sequence numbering 230 used by the first cell 210.
  • the last data packet transmitted by the second cell 220 once the handover or the cell reselection is completed is 6 as illustrated by the sequence numbering 240 used by the second cell 220.
  • the sequence number of the last received data packet provided by the first cell 210 is smaller than the sequence number of the last transmitted data packet by the second cell 220 at the time when the terminal device 216 completes the mobility procedure, then loss of one or more data packets may be determined to have occurred. Therefore, it is beneficial if packet loss may be avoided in such a situation.
  • N info N RE xQ m x R x u
  • N RE the number of resource elements used
  • Q m the modulation order
  • R physical layer code rate
  • u the number of information streams for MIMO configurations.
  • N RE the number of resource elements used
  • Q m the modulation order
  • R physical layer code rate
  • u the number of information streams for MIMO configurations.
  • numerology 0 with 1 ms slot a sample bandwidth of 10 MHz that contains 50 physical resource blocks, PRBs, may be considered for this analysis.
  • the total number of allocated resource elements N RE is 7800 provided that the maximum configuration of 156 resource elements per PRB.
  • the total information bits NJnfo are 2,948 bits for 1 information stream leading to ideal data rate (N info / slot) of 2.95 Mbps.
  • , in L2 packet SN is approximately 96 packets.
  • , in L2 packet SN is approximately 16 packets.
  • a handover procedure that takes place when a terminal device moves from the coverage area of a first cell to a coverage area of a second cell, comprises a handover preparation, a handover execution and a handover completion.
  • the handover preparation comprises exchange of information between the first cell and the second cell to make the second cell ready for serving the terminal device that comes from the first cell.
  • the first cell may be considered as a serving cell and the second cell may be considered as a target cell.
  • the first and the second cell may be adjacent to each other and may therefore be called as neighbour cells.
  • the handover execution comprises a set of procedures that follow the handover preparation.
  • the set of procedures comprises for example commanding the terminal device to detach from the first cell and to synchronize with the second cell.
  • the serving cell may send a sequence number, SN, status transfer message as well as forward buffered data to the second cell.
  • the handover completion comprises a set of procedures that may fully switch the path of the terminal device to the core from the first cell to the second cell.
  • the terminal device may reselect a cell.
  • the cell that is the target for reselection may be called as a candidate cell.
  • a terminal device performs mobility that may be understood to cover both a handover and a reselection procedure.
  • a terminal device may identify one or more cells as candidate cells indicate those to the access node.
  • the access node may then determine the cell (i.e. target cell) to which the terminal device is to be moved.
  • the target cell may be a cell that was determined by the terminal device as a candidate cell and indicated to the access node or it may be a cell that was not identified by the terminal device as a candidate cell.
  • the first cell and the second cell provide the same service with PTM transmissions, but their transmissions are independent and not synchronized.
  • PTM transmissions of the same service in two or more cells may be not synchronized. This may occur for example if some of the cells transmit data faster than others.
  • an indication may be provided to one or more terminal devices that receive the PTM transmission in an RRC Idle/lnactive state that packet loss due to asynchronous independent PTM transmission in a neighboring cell may be experienced.
  • the one or more terminal devices may be receiving multicast service that is delay sensitive using the PTM transmission.
  • the one or more terminal devices may also be required to connect to the access node providing the PTM transmission before reselecting to a neighbour cell in case the neighboring cell is a candidate cell for a reselection and the indication about cells that have asynchronous independent PTM transmission received comprises the candidate cell.
  • the indication may be provided by the access node that provides the serving cell, which is also a camping cell for the one or more terminal devices receiving the indication.
  • the indication may be referred to as a PTM indication.
  • the indication may comprise a request to connect to the access node providing the PTM transmission before reselecting to a neighbour cell. Such request may be an implicit request that causes the terminal device to determine that it is requested to connect to the access node providing the PTM transmission before reselecting to a neighbour cell.
  • a terminal device has received a PTM indication and has identified a candidate cell for reselection, before the execution of the reselection the terminal device is to establish a connection to the access node providing the camping cell and indicate that the connection is established, at least partly, due to the received PTM indication.
  • the indication may have been sent during the initial access procedure or during measurement reporting between the terminal device and the access node providing the camping cell.
  • the terminal device may further transmit to the access node providing the camping cell a measurement report.
  • the measurement report may comprise information regarding a cell that the terminal device identified as a candidate cell for the reselection and information regarding services that the terminal device is receiving.
  • the terminal device may identify more than one candidate cells for reselection.
  • the measurement report may comprise information regarding one or more candidate cells.
  • the access node providing the camping cell may determine if a delay-sensitive multicast service, that the terminal device is receiving, is provided via PTM transmission in the candidate cell and compare delivery status information of the PTM service in the camping cell and also in the candidate cell. If it is determined that the PTM transmission in the candidate cell is ahead of the PTM transmission in the camping cell, the reselection to the candidate cell may be performed and a temporary data radio bearer, DRB, is configured by the access node providing the camping cell for PTM data forwarding to avoid the packet loss.
  • DRB temporary data radio bearer
  • the access node providing the camping cell may release the connection and let the terminal device to proceed to reselect the candidate cell indicated during the connection release.
  • the terminal device may inform the access node about its interest to receive a service using a service interest indication.
  • the service interest indication may identify one or more services the terminal device is interest in although it may not be currently receiving those services.
  • the service interest indication may be received by the access node prior the time when the service is being provided by the access node utilizing a PTM transmission and therefore the access node stores, in this exemplary embodiment, the service interest indication.
  • the access node may compare delivery status information of the PTM service in the camping cell and also in the candidate cell.
  • the reselection to the candidate cell may be performed and a temporary data radio bearer, DRB, is configured by the access node providing the camping cell for PTM data forwarding to avoid the packet loss. Otherwise, the access node may proceed with the handover without configuring the temporary radio bearer.
  • DRB temporary data radio bearer
  • an indication is provided, by the an access node providing the camping cell, to the terminal device that is in an idle mode that the problem may exists. Also, the access node may utilize handover with temporary DRB for forwarding the packet that would be otherwise lost. If the terminal device is in a connected mode, then the access node may have information that the terminal device is receiving a PTM transmission for example based on an interest indication, which may be similar to MBMS interest indication used in LTE. In this case, the access node may trigger DL data delivery status reports based on this information.
  • FIG. 3 illustrates an exemplary embodiment of an access node, that is a gNB with a split architecture.
  • the split architecture may comprise one or more apparatuses providing the functionality of a gNB.
  • the split architecture is such that the central unit, gNB-CU, 310 and the distributed unit, gNB- DU, 320 are split and there is an FI interface between them.
  • the FI interface comprises C-place functions and U-plane functions.
  • the C-plane functions comprises functions such as interface management, system information management, terminal device context management, RRC message transfer, paging and warning message information transfer.
  • U-plane functions comprises functions such as user data transfer and flow control. It is to be noted that in some other exemplary embodiments the split architecture may be different than in this exemplary embodiment.
  • radio bearers may be configured with a shared service data adaptation protocol, SDAP, and PDCP entity in gNB-CU 310.
  • the bearers in the gNB- DU 320 may be configured independently with corresponding lower layer protocol entities and thus there may be as many Fl-U tunnels, 314, as there are cells, i.e. one for each cell.
  • Independent scheduling of PTM transmissions in cell 330 and in cell 340 may now cause the asynchronous transmission in the cells 330 and 340.
  • the asynchronous PTM transmissions may therefore cause a packet loss if a terminal device is to perform reselection while receiving a PTM transmission as explained above.
  • the gNB-CU 310 may further have a connection to the core network.
  • FIG. 4a, 4b and 4c illustrate signalling according to an exemplary embodiment for avoiding packet loss when there is asynchronous PTM transmissions provided by a camping cell and a candidate cell and a terminal device receiving a PTM transmission is to perform reselection.
  • the signalling involves a terminal device, which is represented as UE, gNB-DU and gNB-CU that are comprised in a gNB such as the gNB 300, and access and mobility management function AMF that may be part of the core network.
  • the terminal device receives a PTM transmission provided by a gNB as illustrated by signalling 401.
  • the gNB provides a cell that is a camping cell for the terminal device. Thereby, the terminal device is camping in the camping cell and receives PTM transmission while in an idle mode.
  • there is also functionality on Fl-U interface that allows the gNB-DU to report DL Data Delivery Status for PTM transmissions that are assumed to use RLC unacknowledged mode, UM.
  • the gNB-DU may report a PDCP PDU as successfully delivered in a DL Data Delivery Status message when the entire PDU, which may be segmented, has been transmitted.
  • the gNB-CU in this exemplary embodiment receives the status reports for the camping cell 402 and also for those neighbour cells in which there are PTM transmissions provided 403 and 404.
  • the PTM transmissions may transmit the same transmissions in the camping cell and in the neighbour cells.
  • the gNB-CU analyses the reports continuously and detects how advanced PTM transmissions in the cells are. If it is determined by the gNB-CU that the PTM transmissions are asynchronous among the cells, a PTM indication is transmitted to the terminal device if it camps in a cell in which the PTM transmission is slower than in at least one neighbour cell.
  • a PTM transmission may be understood to be slower than another PTM transmission if it transmits data comprised in a service slower than the other PTM transmission when the service is the same and both PTM transmission transmit the service. This may be detected in some exemplary embodiments based on, at least partly, sequence numbers of the last data packet transmitted at a given time.
  • system information a PTM configuration channel similar to SC-MCCH in LTE SC-PTM or a medium access control (MAC) control element (CE) may be utilized.
  • MAC medium access control
  • CE medium access control control element
  • the gNB-CU sends a MC/BC CONTEXT MODIFICATION REQUEST message 406 to the gNB-DU to request gNB-DU to send an asynchronous PTM indication in MAC CE.
  • a set of F1AP procedures for multicast/broadcast, MC/BC, creation, modification and termination is supported on Fl-C interface.
  • the asynchronous PTM information may comprise scheduling requirements and a list of neighboring cells.
  • PTM data is transmitted to the gNB-DU 407.
  • the then gNB-DU schedules the transmission of MAC CE carrying the asynchronous PTM information 408.
  • the terminal device receives the PTM data transmission with the asynchronous PTM information 409.
  • the PTM indication is transmitted to the terminal device.
  • the terminal device determines that a cell reselection is to be performed the terminal device initiates a connection establishment 410 and initiates access procedure to connect to the access node and thereby to the network.
  • the PTM transmission and the corresponding asynchronous PTM information, such as the asynchronous PTM information, received by the terminal device may include a cell ID of the cell that the terminal device intends to reselect to.
  • the terminal device determines that a connection to the network is to be established.
  • the terminal device performs the initial access procedure 411.
  • the terminal device may indicate during this procedure that the procedure was triggered due to receiving the PTM indication.
  • the terminal device After the initial access procedure, the terminal device performs measurements as configured by the network and transmits measurement report 412 based on the measurements performed. In some exemplary embodiments, in addition to the cells that are reported as per the current requirements, the terminal device may further report cell determined as a candidate cell for cell reselection prior to the initial access procedure. The report may then be utilized by the gNB-CU when it determines a candidate cell for the cell reselection.
  • the RRC MeasurementReport is transmitted to gNB-CU 413.
  • the gNB-CU determines the candidate cell for cell reselection. The determination may comprise considering that the terminal device connected to the network due to the transmission of the PTM indication.
  • the gNB-CU has information regarding if the candidate cell provides multicast or broadcast service using PTM transmission 414. If yes, the gNB-CU continues with the following steps. Otherwise, a switch from PTM to unicast is performed to guarantee service continuity.
  • the gNB-CU continues to receive DL Data Delivery Status for PTM from the camping cell of the terminal device 415.
  • the gNB-CU also continues to receive DL Data Delivery Status for PTM from the candidate cell for the cell reselection 416. If the camping cell lags behind the candidate cell in the PTM transmission, then the gNB- CU initiates a handover which comprises a configuration of a temporary DRB for transmission of PDCP PDUs that the terminal device could miss during reselection to the candidate cell 418. Otherwise, the gNB-CU may release the RRC connection and let the UE perform the reselection procedure.
  • the gNB-CU may indicate in the RRCConnectionRelease message the identity of the cell the terminal device should reselect as that cell will not result in the packet loss due to asynchronous PTM transmissions.
  • the gNB-CU may further store PDCP PDUs for forwarding.
  • the gNB- CU may have a PDCP SDU buffer in which a copy of any PDCP SDU may be stored to stay in the buffer until a discard timer expires.
  • the reselection of a candidate cell may cause delay due to which packet loss may occur even when the terminal device reselects a candidate cell that was ahead in terms of PTM transmission compared to the camping cell.
  • the estimation may be based on, at least partly, an expected handover delay and an expected PTM transmission rate in the candidate cell.
  • the gNB-CU initiates the handover by sending the terminal device a CONTEXT MODIFICATION REQUEST with SpCell ID set to the target cell ID and the request for temporary DRB setup including the tunnel information 419.
  • the gNB-DU configures its resources as requested and sends the RRCConnectionReconfiguration message to the terminal device 420.
  • the terminal device initiates performing the handover.
  • the gNB-DU responds to the gNB-CU with successfully established temporary DRB including tunnel information 421.
  • the terminal device performs random access in the target cell 422. Then, the terminal device receives the PTM transmission in the target cell 423.
  • the terminal device transmits the RRCReconfigurationComplete message to complete the reselection 424.
  • the RRC message is transferred from gNB-DU to gNB-CU 425.
  • the gNB-CU forwards PTM transmission data using the temporary DRB 426.
  • L2 there are two alternatives how L2 may be configured for this.
  • a new PDCP entity for the temporary DRB is utilized in the gNB-CU. This may also allow for the use of different RLC mode such as RLC AM.
  • PDCP PDUs of the PDCP entity used for the PTM transmissions are retransmitted.
  • the DRB data is transmitted to the terminal device 427.
  • the gNB-DU transmits DL Data Delivery Status of the temporary DRB to the gNB-CU 428.
  • the gNB-CU uses the status information to determine whether all data were forwarded to the terminal device.
  • RRC signaling may be considered as an alternative solution in which the terminal device transmits an RRC message to the gNB-CU indicating that it received all data needed and may continue to receive PTM transmission in RRC Idle /Inactive. Once the data is transmitted, the gNB-CU releases the RRC connection 429 and the terminal device continues to receive the service over PTM transmission 430.
  • an implementation for inter-gNB comprises using higher layer sequence numbers such as real-time transport protocol, RTP, to determine whether there is the asynchronous PTM transmission between a serving cell and a target cell.
  • the source gNB may request the target gNB providing the target cell to provide the higher layer sequence number of the last higher layer PDU that has been reported as transmitted/delivered in the target cell based on DL Delivery Status reporting from the target cell.
  • Fig. 5a and 5b illustrate alternative exemplary embodiments of a gNB 500 with a split architecture when temporary DRB is used.
  • the gNB 500 comprises a gNB-CU 510 and a gNB-DU 520 and provides cells 530 and 540.
  • the PDCP PDUs of the PDCP entity used for the PTM transmissions are retransmitted using an additional protocol stack 550 on the gNB-DU 520.
  • a new PDCP 560 entity for the temporary DRB is used, which could also allow for the use of different RLC mode such as RLC AM.
  • FIG. 6 illustrates a flow chart according to an exemplary embodiment.
  • a terminal device connects to an access node in S 6.1.
  • the terminal device provides an indication of interest to receive a service as illustrated in S 6.2. Additionally, the terminal device may indicate an interest to receive also other services.
  • the terminal device receives a first PTM transmission that transmits data comprised in the service the terminal device indicated it was interested in receiving.
  • the terminal device receives an indication that the first PTM transmission is slower than a second PTM transmission provided by an adjacent cell. It is to be noted that, in general, an adjacent cell may be a neighbour cell.
  • the indication may be transmitted in a way that it may be received by a plurality of terminal devices or all terminal devices receiving the service.
  • the terminal device receives a configuration comprising a temporary data radio bearer.
  • the terminal device is to perform mobility from the first cell to the adjacent cell.
  • FIG. 7 illustrates another flow chart according to another exemplary embodiment.
  • a service is provided and one or more PTM transmissions may provide the service.
  • S 7.2 it is determined that a first PTM transmission is used in a first cell and a terminal device is served by the first cell and is receiving the service.
  • S 7.3 it is determined if a second cell adjacent to the first cell provides the service using a second PTM transmission. If not, then the next step is S 7.6. If yes, then as illustrated in S 7.4, it is determined if the first PTM transmission is slower than the second PTM transmission. If not, then the next step is S 7.6.
  • a PTM indication indicating that the first and the second PTM transmissions are asynchronous is transmitted to terminal devices.
  • the PTM indication may comprise information that the first PTM transmission is slower than the second PTM transmission and/or that the terminal device is to connect to an access node providing the first cell in case mobility is to be performed.
  • S 7.6 it is determined that the terminal device is to perform mobility from the first cell to the second cell that is adjacent to the first cell. If the determination in S 7.3 was no, then the next step in S 7.9 in which the mobility is performed and transmission is switched to unicast. If the determination in S 7.4 was no, then the mobility is performed as illustrated in S 7.8. Otherwise, the next step is S7.7 in which a temporary data radio bearer is configured and then the next step is S 7.8 in which the mobility is performed.
  • an access node determined that a terminal device is receiving data comprised in a service the determination may be done for example based on receiving from the terminal device one or more of the following: a service interest indication indicating that the terminal device wishes to receive the service, an indication during an initial access procedure informing the access node that the procedure was triggered due to receiving a PTM indication indicating that there are asynchronous PTM transmissions in one or more adjacent cells, that may be neighbour cells and/or receiving a measurement report.
  • the information received by the access node may comprises information that uniquely identifies the service UE is receiving at gNB such as a service ID, a temporary mobile group identity, a multicast or broadcast network address.
  • a terminal device may be understood as a target recipient for data comprised in a service if it is determined that the terminal device is receiving data comprised in the service and/or an indication has been received indicating that the terminal device is interested in receiving the service and thereby data comprised in the service.
  • the exemplary embodiments described above may have for example one or more of the following benefits.
  • the gNB is allowed to detect pro-actively whether PTM transmissions of the same service in two or more cells are not synchronized.
  • the gNB may notify the UE about detection of potential packet loss due to asynchronous independent PTM transmission in a neighbour cell.
  • a terminal device that has determined a candidate cell for reselection is allowed to be connected to the gNB such that serving cell update for the UE is performed by using components of a handover procedure that allows lossless delivery of L2 packets.
  • a terminal device is allowed to notify the gNB that the connection establishment is for PTM reception.
  • the gNB is allowed to determine and/or modify the target cell to which the terminal device should update its serving cell based on a measurement report from the terminal device as well as the knowledge of the gNB regarding of the radio resource management in the neighbor cells.
  • a flexible and reliable transmission of the missed L2 packets by using temporary DRB for the case where the PTM transmission in the target cell is ahead of the PTM transmission in the source cell may be achieved.
  • the temporary DRB as well as the connection with the gNB are released upon complete reception of the missed L2 packets by the UE.
  • the exemplary embodiments described may also be beneficial for services that cannot rely on an application or transport layer mechanism to recover loss packets because of low latency requirements.
  • the apparatus 800 may be an electronic device comprising one or more electronic circuitries.
  • the apparatus 800 may comprise a communication control circuitry 810 such as at least one processor, and at least one memory 820 including a computer program code (software) 822 wherein the at least one memory and the computer program code (software) 822 are configured, with the at least one processor, to cause the apparatus 800 to carry out any one of the example embodiments of the access node described above.
  • the memory 820 may 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 comprise a configuration database for storing configuration data.
  • the configuration database may store current neighbour cell list, and, in some example embodiments, structures of the frames used in the detected neighbour cells.
  • the apparatus 800 may further comprise a communication interface 830 comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols.
  • the communication interface 830 may provide the apparatus with radio communication capabilities to communicate in the cellular communication system.
  • the communication interface may, for example, provide a radio interface to terminal devices.
  • the apparatus 800 may further comprise another interface towards a core network such as the network coordinator apparatus and/or to the access nodes of the cellular communication system.
  • the apparatus 800 may further comprise a scheduler 840 that is configured to allocate resources.
  • FIG. 9 illustrates an apparatus 900, which may be an apparatus such as, or comprised in, a terminal device, according to an example embodiment.
  • the apparatus 900 comprises a processor 910.
  • the processor 910 interprets computer program instructions and processes data.
  • the processor 910 may comprise one or more programmable processors.
  • the processor 910 may comprise programmable hardware with embedded firmware and may, alternatively or additionally, comprise one or more application specific integrated circuits, ASICs.
  • the processor 910 is coupled to a memory 920.
  • the processor is configured to read and write data to and from the memory 920.
  • the memory 920 may comprise one or more memory units.
  • the memory units may be volatile or non-volatile. It is to be noted that in some example embodiments there may be one or more units of non volatile memory and one or more units of volatile memory or, alternatively, one or more units of non-volatile memory, or, alternatively, one or more units of volatile memory.
  • Volatile memory may be for example RAM, DRAM or SDRAM.
  • Non-volatile memory may be for example ROM, PROM, EEPROM, flash memory, optical storage or magnetic storage. In general, memories may be referred to as non-transitory computer readable media.
  • the memory 920 stores computer readable instructions that are execute by the processor 910. For example, non-volatile memory stores the computer readable instructions and the processor 910 executes the instructions using volatile memory for temporary storage of data and/or instructions.
  • the computer readable instructions may have been pre-stored to the memory 920 or, alternatively or additionally, they may be received, by the apparatus, via electromagnetic carrier signal and/or may be copied from a physical entity such as computer program product. Execution of the computer readable instructions causes the apparatus 900 to perform functionality described above.
  • a “memory” or “computer-readable media” may be any non-transitory media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.
  • the apparatus 900 further comprises, or is connected to, an input unit 930.
  • the input unit 930 comprises one or more interfaces for receiving a user input.
  • the one or more interfaces may comprise for example one or more motion and/or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons and one or more touch detection units.
  • the input unit 930 may comprise an interface to which external devices may connect to.
  • the apparatus 900 also comprises an output unit 940.
  • the output unit comprises or is connected to one or more displays capable of rendering visual content such as a light emitting diode, LED, display, a liquid crystal display, LCD and a liquid crystal on silicon, LCoS, display.
  • the output unit 940 may comprise two displays to render stereoscopic visual content. One display to render content to the left eye and the other display to render content to the right eye.
  • the output unit 940 may further comprise a transmission unit, such as one or more waveguides or one or more lenses, to transfer the rendered visual content to the user’s field of view.
  • the output unit 940 further comprises one or more audio outputs.
  • the one or more audio outputs may be for example loudspeakers or a set of headphones.
  • the apparatus 900 may further comprise a connectivity unit 950.
  • the connectivity unit 950 enables wired and/or wireless connectivity to external networks.
  • the connectivity unit 950 may comprise one or more antennas and one or more receivers that may be integrated to the apparatus 900 or the apparatus 900 may be connected to.
  • the connectivity unit 950 may comprise an integrated circuit or a set of integrated circuits that provide the wireless communication capability for the apparatus 900.
  • the wireless connectivity may be a hardwired application specific integrated circuit, ASIC.
  • apparatus 900 may further comprise various component not illustrated in the FIG. 9.
  • the various components may be hardware component and/or software components.

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Abstract

Un procédé consiste à : déterminer qu'une première transmission point à multipoint est prévue dans une première cellule pour transmettre des données comprises dans un service et qu'une seconde transmission point à multipoint est prévue dans une seconde cellule pour transmettre les données comprises dans le service ; déterminer que la première transmission multipoint et la seconde transmission multipoint sont asynchrones et que la première transmission point à multipoint est plus lente que la seconde transmission point à multipoint ; fournir, à un dispositif terminal, une indication concernant la détermination que la première transmission multipoint et la seconde transmission multipoint sont asynchrones ; déterminer que le dispositif terminal doit effectuer une mobilité de la première cellule vers la seconde cellule ; et transmettre des informations concernant la seconde cellule au dispositif terminal.
PCT/EP2020/056056 2020-03-06 2020-03-06 Prévention de perte de paquets dans des transmissions point à multipoint WO2021175443A1 (fr)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010063226A1 (fr) * 2008-12-01 2010-06-10 华为技术有限公司 Procédé, appareil et système de communication pour transmettre les données de service mbms
EP3079400A1 (fr) * 2014-01-03 2016-10-12 Huawei Technologies Co., Ltd. Procédé de transfert d'équipement utilisateur et station de base

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010063226A1 (fr) * 2008-12-01 2010-06-10 华为技术有限公司 Procédé, appareil et système de communication pour transmettre les données de service mbms
EP3079400A1 (fr) * 2014-01-03 2016-10-12 Huawei Technologies Co., Ltd. Procédé de transfert d'équipement utilisateur et station de base

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