WO2021043403A1

WO2021043403A1 - Data transmission

Info

Publication number: WO2021043403A1
Application number: PCT/EP2019/073697
Authority: WO
Inventors: David NAVRÁTIL; Mikko SÄILY; Athul Prasad
Original assignee: Nokia Technologies Oy
Priority date: 2019-09-05
Filing date: 2019-09-05
Publication date: 2021-03-11

Abstract

An apparatus, method and computer program product for: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

Description

DATA TRANSMISSION

TECHNICAL FIELD

The present application relates generally to data transmission. More specifically, the present application relates to coordinating data transmission. BACKGROUND

The amount of content delivered over the Internet has been increased remarkably over the past years. Video content forms a big part of total traffic served on the Internet.

SUMMARY Various aspects of examples of the invention are set out in the claims.

The scope of protection sought for various embodiments of the invention is set out by the independent claims. The examples and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

According to a first aspect of the invention, there is provided an apparatus comprising means for performing: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

According to a second aspect of the invention, there is provided a method comprising: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

According to a third aspect of the invention, there is provided a computer program comprising instructions for causing an apparatus to perform at least the following: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave. According to a fourth aspect of the invention, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to with the at least one processor, cause the apparatus at least to: schedule a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, schedule a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinate the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave. According to a fifth aspect of the invention, there is provided a non- transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

According to a sixth aspect of the invention, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

According to a seventh aspect of the invention, there is provided an apparatus comprising means for performing: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer, receiving the multicast data via the first data radio bearer according to the first reception cycle and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle. According to an eight aspect of the invention, there is provided a method comprising: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer, receiving the multicast data via the first data radio bearer according to the first reception cycle and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

According to a ninth aspect of the invention, there is provided a computer program comprising instructions for causing an apparatus to perform at least the following: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer, receiving the multicast data via the first data radio bearer according to the first reception cycle and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle. According to a tenth aspect of the invention, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to with the at least one processor, cause the apparatus at least to: receive an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer according to a second reception cycle, receive the multicast data via the first data radio bearer according to the first reception cycle and determine, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

According to an eleventh aspect of the invention, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer, receiving the multicast data via the first data radio bearer according to the first reception cycle and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

According to a twelfth aspect of the invention, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer, receiving the multicast data via the first data radio bearer according to the first reception cycle and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

Figure 1 shows a part of an exemplifying radio access network in which examples of disclosed embodiments may be applied;

Figure 2 shows a block diagram of an example apparatus in which examples of the disclosed embodiments may be applied;

Figure 3A shows an example of reception cycles;

Figure 3B shows another example of reception cycles;

Figure 4 shows a block diagram of an example overall architecture in which examples of disclosed embodiments may be applied; Figure 5A illustrates an example signalling diagram incorporating aspects of the examples of the invention;

Figure 5B illustrates another example signalling diagram incorporating aspects of the examples of the invention;

Figure 6 illustrates an example method according to an example embodiment of the invention;

Figure 7 illustrates another example method according to an example embodiment of the invention;

Figure 8 illustrates a further example method according to an example embodiment of the invention; Figure 9 illustrates a yet further example method according to an example embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The following embodiments are exemplifying. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

Example embodiments relate to coordinating a first transmission of multicast data and a second transmission of the multicast data. More particularly, example embodiments relate to coordinating a first transmission cycle and a second transmission cycle.

Example embodiments relate to an apparatus at a network side and an apparatus at a client side. The apparatus at a network side may be comprised by an access point such as a base station and the apparatus at a client side may be a terminal device/user equipment such as a mobile computing device.

According to an example embodiment, an apparatus is configured to schedule a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, schedule a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer, and coordinate the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

According to an example embodiment, an apparatus at a client side is configured to receive an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer according to a second reception cycle, receive the multicast data via the first data radio bearer according to the first reception cycle and determine, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

In the following, different exemplifying embodiments will be described using, as an example of an access architecture to which the embodiments may be applied, a radio access architecture based on long term evolution advanced (LTE Advanced, LTE-A) or new radio (NR, 5G), without restricting the embodiments to such an architecture, however. It is obvious for a person skilled in the art that the embodiments may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, the same as E-UTRA), wireless local area network (WLAN or WiFi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet Protocol multimedia subsystems (IMS) or any combination thereof.

Figure 1 depicts examples of simplified system architectures only showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in Figure 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 Figure 1.

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.

The example of Figure 1 shows a part of an exemplifying radio access network.

Figure 1 shows user 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 physical link from a user device to a (e/g)NodeB is called uplink or reverse link and the physical link from the (e/g)NodeB to the user device is called downlink or forward link. It should be appreciated that (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. A communications 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 not only for signalling purposes but also for routing data from one (e/g)NodeB to another. 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, an access node, 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. From the transceivers of the (e/g)NodeB, a connection is provided to an antenna unit that establishes bi-directional radio links to user devices. 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). Depending on the system, the counterpart on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW), for providing connectivity of user devices (UEs) to external packet data networks, or mobile management entity (MME), etc.

The user device (also called UE, user equipment, user terminal, terminal 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 user device may be implemented with a corresponding apparatus, such as a relay node. An example of such a relay node is a layer 3 relay (self-backhauling relay) towards the base station.

The user device refers, for example, to a wireless mobile communication device operating with or without a subscriber identification module (SIM), 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, navigation device, vehicle infotainment system, and multimedia device, or any combination thereof. It should be appreciated that a user device may also be 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 user 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 user device may also utilise cloud. In some applications, a user 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 user device (or in some embodiments a layer 3 relay node) is configured to perform one or more of user equipment functionalities. The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal or user equipment (UE) just to mention but a few names or apparatuses. A wireless device is a generic term that encompasses both the access node and the terminal device.

Various techniques described herein may also be applied to a cyber physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected 1CT devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. 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.

Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in Figure 1) may be implemented. 5G enables using multiple input - multiple output (M1MO) 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. 5G mobile communications supports a wide range of content delivery use cases and related applications including, for example, video streaming, audio streaming, augmented reality, gaming, map data, 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 integradable 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. In other words, 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). 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 require to bring the content close to the radio which leads to local break out and multi-access edge computing (MEC). 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, 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 Figure 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 (NVF) and software defined networking (SDN). 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). It should also be understood that the distribution of functions between core network operations and base station operations may differ from that of the LTE or even be non-existent. Some other technology advancements probably to be used are Big Data and all-IP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks are being designed to support multiple hierarchies, where MEC servers can be placed between the core and the base station or node B (gNB). It should be appreciated that MEC can be applied in 4G networks as well.

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 (loT) devices or for passengers on board of vehicles, or ensuring service availability for critical communications, and future railway, maritime, and/or 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). 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.

It is obvious for a person skilled in the art that the depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of (e/g)NodeBs, the user 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 Figure 1 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of cells. In multilayer networks, 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.

For fulfilling the need for improving the deployment and performance of communication systems, the concept of "plug-and-play" (e/g)NodeBs has been introduced. A network which is able to use "plug-and-play" (e/g)Node Bs, includes, in addition to Home (e/g)NodeBs (H(e/g)nodeBs), a home node B gateway, or ll

HNB-GW (not shown in Figure 1). 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.

As commonly known in connection with wireless communication systems, control or management information is transferred over a radio interface, e.g. between the terminal device 100 and the access node 104.

Multimedia consumption has increased significantly during the past years and it is expected to grow also in the future with the advent of live streaming capabilities in popular social media websites and/or applications. Content delivery may be enabled through mobile network of fixed network or a combination thereof.

In order to provide a more efficient use of network resources, different kinds of transmission modes may be used. Examples of different transmission modes comprise broadcast transmission, unicast transmission, multicast transmission and anycast transmission. Broadcast transmission may be used to offload a portion of traffic peak when users are consuming common content, for example, during major sporting events or concerts. Broadcast transmission enables delivering content to a large number of user equipment (UE) without the need to deliver the same content to each user individually. Broadcast transmission comprises providing data from a single source to all receivers within a defined geographical area. The defined geographical area may comprise, for example, a cell corresponding to a base station. Therefore, broadcast transmission may be referred to as one-to-all transmission.

Content may also be delivered to a UE using unicast transmission, multicast transmission or anycast transmission. Unicast transmission comprises providing data from a single source to a specified receiver and may, therefore, be referred as one-to-one transmission. A unicast transmission mode comprises scheduling data traffic using a unicast data radio bearer (DRB).

Multicast transmission comprises providing data from a single source to a plurality of defined receivers. The plurality of defined receivers may comprise, for example, members of a particular multicast group. Therefore, multicast transmission may be referred to as one-to-many transmission. A multicast transmission mode comprises scheduling data traffic using a multicast data radio bearer (DRB). Anycast transmission comprises providing data from a single source to a nearest receiver. Therefore, anycast transmission may be referred to as one-to nearest transmission.

A system capable of exploiting a mix of unicast and multicast/broadcast may be referred to as Xcast. An Xcast architecture allows for scheduling multicast data over a set of radio bearers where each of these bearers is either a unicast data radio bearer (DRB) or multicast data radio bearer (DRB). An Xcast architecture may also enable dynamically selecting and/or switching between point-to-point (PTP) and point-to-multipoint (PTM) transmissions. For example, assuming that a plurality of active user equipment (UE) are subscribed to a same multicast service and UE1 and UE2 are located such that they cannot be reached by a single radio beam, the RAN may select a unicast transmission mode for UE1 and UE2, and a multicast transmission mode for the other UE.

Point-to-multipoint transmission may be provided using a single cell- point to multipoint (SC-PTM) architecture or a multicast broadcast single frequency network (MBSFN) architecture. In SC-PTM each base station transmits multicast/broadcast content to a plurality of UEs independently, whereas in MBSFN a plurality of base stations are synchronized to transmit the same multicast/broadcast content at the same time.

A bearer is a telecommunication service that is used for transferring user data and/or control signals between at least two pieces of equipment. There are different types of bearers: a data bearer configured to transfer data, a signalling bearer configured to carry signalling data and a radio bearer between a base station and user equipment. In other words, a bearer is a tunnel used for connecting a user equipment to Packet Data Networks (PDN) such as the internet. Different bearer services may differ by their information transfer characteristics (e.g. data transfer rate, direction(s) of data flow, type of transfer and/or other physical characteristics), methods of accessing the service, interworking requirements and other general attributes. Radio resource control (RRC) signalling is responsible for setting up a bearer between the UE and the RAN.

A radio access network (RAN), such as an eNodeB or a gNodeB, may be configured to select unicast and multicast/broadcast bearers to transmit multicast data to a group of UEs interested in the service. In practise, RRC may configure a UE such that the UE may receive downlink shared channel (DL-SCH) cell radio network temporary identifier (C-RNT1) for unicast transmission and DL-SCH group radio network temporary identifier (G-RNT1) for multicast transmission. Continuous reception refers to a situation where a UE is continuously in a wake-up mode. In other words, the UE monitors the physical downlink control channel (PDCCH) continuously for any data transmission from a RAN. However, this kind of operation causes unnecessary battery consumption.

In order to reduce battery consumption of a UE, a mechanism called discontinuous reception (DRX) may be provided. Network may configure DRX to control UE’s monitoring of PDCCH. Monitoring may comprise, for example, monitoring for a radio network temporary identifier (RNTI) on PDCCH. DRX has a sleep state and an active state, and the UE switches between the states periodically. During the active state, the UE checks whether it should be active or go to sleep. If a RAN has data transmission for the UE, the UE keeps the radio frequency (RF) module on to monitor PDCCH and receive data. If there is no data transmission from the RAN, the UE goes to sleep and turns off its radio interface. In other words, DRX functionality reduces power consumption by turning off the radio frequency (RF) module in the UE, when there is no data transmission for the UE. A time period comprising an active state and a sleep state is referred to as a DRX cycle. In other words, a DRX cycle specifies the periodic repetition of the active state followed by a possible sleep state.

DRX operation is controlled by a set of configuration parameters. The set of configuration parameters may comprise an onDurationTimerSCPTM parameter that specifies the duration of "ON time" within one DRX cycle. The set of configuration parameter may further comprise a drx-lnActivityTimerSCPTM parameter that specifies how long a UE should remain "ON" after the reception of PDCCH. When this timer is on, the UE remains in "ON state" which may extend UE ON period into the period which is "OFF" period otherwise. The set of configuration parameters may further comprise a SCPTM-SchedulingCycle parameter that specifies the DRX cycle length. The timing of sleeping and waking up may be determined by a RAN using an RRC message.

DRX for multicast/broadcast and DRX for unicast are independent procedures. The active time of a DRX procedure may at least partially interleave with the active time of another DRX procedure. For example, the active time of DRX procedure for multicast may interleave with the active time of DRX procedure for unicast. Treating DRX periods as independent in a system that may transmit multicast data on a set of unicast and multicast radio bearers may cause non- optimal operation of a UE that could potentially receive and decode multicast data on both unicast and multicast radio bearers. Further, this may lead to sub-optimal utilization of system resources in a scenario of Xcast traffic and high UE power consumption. The example of Figure 2 shows an exemplifying apparatus.

Figure 2 is a block diagram depicting an apparatus 200 operating in accordance with an example embodiment of the invention. The apparatus 200 may be, for example, an electronic device such as a chip, chip-set, an electronic device, a network function or an access node such as a base station. The apparatus comprises one or more control circuitry, such as at least one processor 210, and at least one memory 260, including one or more algorithms such as a computer program instructions 220 wherein the at least one memory 260 and the computer program instructions 220 are configured, with the at least one processor 210 to cause the apparatus 200 to carry out any of the example functionalities described below. In the example of Figure 2, the apparatus 200 is comprised by a base station.

In the example of Figure 2, the processor 210 is a central unit operatively connected to read from and write to the memory 260. The processor 210 may also be configured to receive control signals received via an input interface and/or the processor 210 may be configured to output control signals via an output interface. In an example embodiment the processor 210 may be configured to convert the received control signals into appropriate commands for controlling functionalities of the apparatus.

The memory 260 stores computer program instructions 220 which when loaded into the processor 210 control the operation of the apparatus 200 as explained below. In other examples, the apparatus 200 may comprise more than one memory 260 or different kinds of storage devices.

Computer program instructions 220 for enabling implementations of example embodiments of the invention or a part of such computer program instructions may be loaded onto the apparatus 200 by the manufacturer of the apparatus 200, by a user of the apparatus 200, or by the apparatus 200 itself based on a download program, or the instructions can be pushed to the apparatus 200 by an external device. The computer program instructions may arrive at the apparatus 200 via an electromagnetic carrier signal or be copied from a physical entity such as a computer program product, a memory device or a record medium such as a Compact Disc (CD), a Compact Disc Read-Only Memory (CD-ROM), a Digital Versatile Disk (DVD) or a Blu-ray disk.

According to an example embodiment, the apparatus 200 is configured to communicate with another apparatus 100. The apparatus 100 may comprise a terminal device such as user equipment (UE) 100. The user equipment may be, for example, a mobile computing device. According to an example embodiment, the apparatus 200 is located in an access network such as a radio access network (RAN). A radio access network (RAN) may comprise a base station, such as an eNodeB or a gNodeB, and antennas that cover a given geographical region. According to an example embodiment, the apparatus 200 is a base station.

According to an example embodiment, the apparatus 200 is configured to transmit data during a transmission opportunity. Data is transmitted using radio frames having a particular frame structure. A frame structure may comprise a structure that is designed for Frequency Division Duplex (FDD) or a frame structure that is designed for Time Division Duplex (TDD). In FDD a first operating channel is provided for downlink transmission and a second operating channel is provided for uplink transmission. In other words, different spectrum frequencies may be used at the same time. In TDD both uplink transmission and downlink transmission use the same frequency spectrum, but at different times. Typically, a radio frame is of 10 ms duration and a frame is further divided into subframes. A subframe is further divided into slots.

A transmission opportunity comprises a time interval for transmitting or initiating transmitting data. An apparatus may transmit multiple radio frames consecutively during the time interval. According to an example embodiment, the apparatus 200 is configured to transmit multicast data to a plurality of terminal devices such as user equipment (UE) 100. Multicast data may comprise multimedia data, for example, video content. The apparatus may be configured to transmit multicast data using a unicast transmission and/or using a multicast/broadcast transmission. According to an example embodiment, the apparatus 200 is configured to send configuration information to a terminal device such as UE 100. The configuration information may comprise information relating to receiving multicast data via different data radio bearers (DRBs). Different transmission bearers may comprise, for example, a unicast bearer and/or multicast/broadcast bearer. The configuration information may comprise one or more parameters relating to receiving multicast data by the UE 100. The UE 100 is configured to receive the configuration information and operate according to the received configuration information.

According to an example embodiment, the apparatus 200 is configured to schedule a first data transmission to a terminal device via a first data radio bearer and a second data transmission to the terminal via a second data radio bearer. According to an example embodiment, the first data radio bearer comprises a multicast data radio bearer and the second data radio bearer comprises a unicast data radio bearer. According to another example embodiment, the first data radio bearer comprises a unicast data radio bearer and the second data radio bearer comprises a multicast data radio bearer.

According to an example embodiment, the apparatus 200 is configured to schedule a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer. Scheduling may be performed by a scheduler comprised by the apparatus 200. Scheduling may comprise determining a point of time for initiating a transmission of data using one ore more frames. Additionally or alternatively, scheduling may comprise initiating a transmission of data at a determined point in time. The apparatus 200 may be configured to provide different scheduling for different data radio bearers (DRBs). For example, the apparatus 200 may be configured to provide UE specific scheduling for a unicast DRB and group scheduling for a multicast DRB. Scheduling refers to a dynamic resource allocation of uplink and downlink radio resources and may be performed by medium access control (MAC) in a base station. The scheduling takes into the account one or more of data buffer status, quality of service requirements, radio conditions. According to an example embodiment, the first transmission of multicast data comprises a multicast transmission of multicast data and the first reception cycle comprises a multicast reception cycle.

According to an example embodiment, a reception cycle comprises a time period comprising an active period and an inactive period. The first reception cycle may comprise a discontinuous reception cycle (DRX) comprising an active period and an inactive period. During the active period a terminal device (e.g. UE 100) is in an active state, for example, the terminal device monitors PDCCH and, if indicated by PDCCH, receives data, and during the inactive period the terminal device is in an inactive state, for example, in a sleep state. According to an example embodiment, the apparatus 200 is configured to schedule a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer. As mentioned above, scheduling may comprise determining a point of time for initiating transmission of data. Additionally or alternatively, scheduling may comprise initiating transmission of data at a determined point in time. Scheduling may be performed by a scheduler comprised by the apparatus 200. According to an example embodiment, the second transmission of multicast data comprises a unicast transmission of multicast data and the second reception cycle comprises a unicast reception cycle.

Similarly to the first reception cycle, the second reception cycle may comprise a discontinuous reception cycle (DRX) comprising an active period and an inactive period. During the active period a terminal device is in an active state, for example, the terminal device monitors and receives data, and during the inactive period the terminal device is in an inactive state, for example, in a sleep state. According to an example embodiment, the apparatus 200 is configured to send an indication to the terminal device that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer. An indication that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer may comprise an indication that the multicast data transmitted via the first data radio bearer and the second data radio bearer are the same.

The indication that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer may be signaled in PDCCH, for example, using a new a downlink control information (DCI) field or in medium access control (MAC) packet data unit (PDU) with a new control element.

According to an example embodiment, the apparatus 200 is configured to send the indication that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer during an active period of the second reception cycle. For example, assuming the first reception cycle comprises a multicast reception cycle and the second reception cycle comprises a unicast reception cycle, the apparatus 200 is configured to send the indication during an active period of the unicast reception cycle. Without limiting the scope of the claims, an advantage of indicating that the multicast data transmitted via the first radio bearer corresponds to the multicast data transmitted via the second data radio bearer may be that it enables optimization of network resources. For example, based on the indication a terminal device may be configured to attempt to receive a multicast transmission if a unicast transmission fails or to receive a unicast transmission if a multicast transmission fails when a unicast reception precedes a multicast reception or a multicast reception precedes unicast reception, respectively.

According to an example embodiment, the indication that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer comprises a reference to the first data radio bearer. The reference could be, for example, an index to a list of configured DRBs. For example, assuming the first radio bearer comprises a multicast bearer and the second bearer comprises a unicast bearer, it may be useful to refer to a particular multicast bearer in case the terminal device is receiving more than one multicast transmission. According to an example embodiment, the apparatus 200 is configured to coordinate the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

Coordinating the first transmission and the second transmission may comprise coordinating the order of the first transmission and the second transmission by coordinating the order of the first reception cycle and the second reception cycle. The first cycle and the second cycle may be sequential or partially interleave. Additionally or alternatively, coordinating may comprise coordinating timing of the first transmission and the second transmission with relative to each other.

Interleaving a sequence of the first reception cycle and the second reception cycle may comprise interleaving a sequence of the first reception cycle and the second reception cycle with or without an overlap, or a gap between the first reception cycle and the second reception cycle. According to an example embodiment, the apparatus 200 is configured to interleave a sequence of the first reception cycle and the second reception cycle without an overlap. In other words, assuming the first reception cycle is scheduled to precede the second reception cycle, the apparatus 200 is configured to interleave a sequence of the first reception cycle and the second reception cycle such that the first reception cycle is lapsed before the second reception cycle is initiated. As another example, assuming the second reception cycle is scheduled to precede the first reception cycle, the apparatus 200 is configured to interleave a sequence of the first reception cycle and the second reception cycle such that the second reception cycle is lapsed before the first reception cycle is initiated. According to another example embodiment, the apparatus 200 is configured to interleave a sequence of the first reception cycle and the second reception cycle such that a portion of the second reception cycle overlaps with a portion of the first reception cycle, when the first transmission is scheduled to precede the second transmission. A portion of the first reception cycle may comprise, for example, at least a portion of the inactive period of the first reception cycle. For example, assuming the first reception cycle comprises a multicast reception cycle and the second reception cycle comprises a unicast reception cycle, the apparatus may be configured to interleave the multicast reception cycle and the unicast reception cycle such that the unicast reception cycle at least partially overlaps with the multicast reception cycle. As another example, assuming the first reception cycle comprises a unicast reception cycle and the second reception cycle comprises a multicast reception cycle, the apparatus 200 may be configured to interleave the unicast reception cycle and the multicast reception cycle such that the multicast reception cycle at least partially overlaps with the unicast reception cycle. According to an example embodiment, the apparatus 200 is configured to coordinate the first transmission and the second transmission such that the first reception cycle and the second reception cycle at least partially interleave, and the first reception cycle precedes the second reception cycle. In other words, assuming the first transmission comprises multicast transmission and the second transmission comprises unicast transmission, the apparatus 200 is configured to transmit multicast transmission to the terminal device via the multicast data bearer during the active time of multicast reception cycle and transmit unicast transmission to the terminal device via the unicast data bearer during the active time of unicast reception cycle. According to an example embodiment, the apparatus 200 is configured to instruct UE 100 to send an uplink notification on successful reception of a first transmission. For example, assuming the first transmission comprises a multicast transmission, the apparatus 200 is configured to instruct a UE to send an uplink notification on successful reception of the multicast transmission. The UE 100 may be configured to send the uplink notification during a second reception cycle. Alternatively, the UE 100 may be configured to send the notification, if there is a gap between the first reception cycle and the second reception cycle, during the gap-

The apparatus 200 may be configured to perform different operations in dependence upon whether a transmission was successfully received by the terminal device or not. According to an example embodiment, the apparatus 200 is configured to, in response to receiving an indication that the first transmission is successfully received, skip the second reception cycle. Skipping a reception cycle may comprise, for example, cancelling a scheduled transmission or terminating a started transmission.

According to another example embodiment, the apparatus 200 is configured to, in response to receiving an indication that the first transmission is successfully received, schedule a transmission of new data for the second reception cycle. For example, the apparatus 200 may be configured to schedule a transmission of new data for the second reception cycle in response to receiving an indication from the terminal device that the first transmission is successfully received during the first reception cycle. As another example, the apparatus 200 may be configured to transmit the scheduled second transmission in response to receiving an indication from the terminal device that the reception of the first transmission is failed during the first reception cycle.

Without limiting the scope of the claims, an advantage of skipping a reception cycle and/or scheduling new data for the reception cycle may be that usage of network resources are optimized.

As stated above the apparatus 200 is configured to communicate with a terminal device such as user equipment 100. A terminal device is an apparatus 100 comprising one or more control circuitry, such as at least one processor, and at least one memory, including one or more algorithms such as a computer program instructions wherein the at least one memory and the computer program instructions are configured, with the at least one processor to cause the apparatus to carry out any of the example functionalities described below.

According to an example embodiment, an apparatus 100 is configured to receive an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer according to a second reception cycle. Without limiting the scope of the claims, an advantage of receiving an indication that multicast data transmitted via a first data radio bearer corresponds to data transmitted via a second data radio bearer may be that a terminal device may determine whether there is a need to receive the transmission of corresponding data during the second reception cycle if a previous transmission is successfully received during the first reception cycle. This may reduce battery consumption in the terminal device. The indication may be received from the apparatus 200 such as a base station. According to an example embodiment, the apparatus 100 is configured to receive the indication during the first reception cycle.

According to an example embodiment, the apparatus 100 is configured to receive the multicast data transmitted via the first data radio bearer according to a first reception cycle. According to an example embodiment, the first reception cycle comprises a unicast reception cycle and the second reception cycle comprises a multicast reception cycle.

The apparatus 100 (e.g. a terminal device such asUE) maybe configured to determine whether a transmission is successfully received or not. According to an example embodiment, the apparatus 100 is configured to determine whether the first transmission is successfully received.

According to an example embodiment, the apparatus 100 is configured to determine, based on the received indication and the received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle. The operation may comprise skipping the second reception cycle in response to determining that the first transmission is successfully received or the operation may comprise receiving a second transmission in response to determining that reception of the first transmission is failed. According to an example embodiment, the user equipment is configured to skip the second reception cycle, in response to determining that the first transmission is successfully received. According to an example embodiment, the user equipment is configured to receive a second transmission, in response to determining that the reception of the first transmission is failed. According to an example embodiment, the apparatus 200 comprises means for performing features of the apparatus 200, wherein the means for performing comprises at least one processor 210, at least one memory 260 including computer program code 220, the at least one memory 260 and the computer program code 220 configured to, with the at least one processor 210, cause the performance of the apparatus 200. The means for performing features of the apparatus 200 may comprise, for example, means for scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer, means for scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer, and means for coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

The means for performing may further comprise means for sending an indication to the terminal device that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer, means for sending the indication during an active period of the first reception cycle, means for coordinating the first transmission and the second transmission such that the first reception cycle and the second reception cycle at least partially interleave and the first reception cycle precedes the second reception cycle. The means for performing may further comprise means for skipping, in response to receiving an indication that the first transmission is successfully received, the second reception cycle or means for scheduling, in response to receiving an indication that the first transmission is successfully received, a transmission of new data for the second reception cycle.

According to an example embodiment, the apparatus 100 comprises means for performing features of the apparatus 100, wherein the means for performing comprises at least one processor 210, at least one memory 260 including computer program code 220, the at least one memory 260 and the computer program code 220 configured to, with the at least one processor 210, cause the performance of the apparatus 100. The means for performing features of the apparatus 100 may comprise, for example, means for receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer according to a second reception cycle, means for receiving the multicast data via the first data radio bearer according to the first reception cycle and means for determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

The means for performing may further comprise means for receiving the indication during the first reception cycle, means for skipping the second reception cycle, in response to determining that the first transmission is successfully received and means for receiving a second transmission in response to determining that the reception of the first transmission is failed.

Figures 3A and 3B illustrate examples of reception cycles. The reception cycle may interleave with or without an overlap. Figures 3A and 3B illustrate examples of a first reception cycle and a second reception cycles interleaving. In the example of Figure 3, the first portion 305 corresponds to a first reception cycle and the second portion 310 corresponds to a second reception cycle. A reception cycle may further comprise an active period and an inactive period.

The first reception cycle and the second reception cycle may interleave partially or completely. Complete interleaving comprises a first reception cycle and a second reception cycle that follow each other without overlap. Partial interleaving comprises a first reception cycle and a second reception cycle that overlap with each other at least partially. For example, an active period of the second reception cycle may overlap with an inactive period of the first reception cycle.

In the example of Figure 3A, a unicast reception cycle precedes a multicast reception cycle. The dashed line illustrating the multicast reception cycle indicates that different operations may be performed during the multicast reception cycle in dependence upon whether a unicast transmission is successfully received during the unicast reception cycle and whether an indication that multicast data transmitted during the unicast reception cycle corresponds to multicast data transmitted during the multicast reception cycle. For example, a terminal device may be configured to skip the multicast reception cycle, if the unicast transmission is successfully received during the unicast reception cycle and the indication is received. It should be noted that even though the terminal device may be configured to skip the multicast reception cycle, a base station may still be configured to transmit a multicast transmission during the multicast reception cycle. On the other hand, if the reception of unicast transmission is failed during the unicast reception cycle, a multicast transmission may be received during the multicast reception cycle.

In the example of Figure 3B, a multicast reception cycle precedes a unicast reception cycle. The dashed line illustrating the unicast reception cycle indicates that different operations may be performed during the unicast reception cycle in dependence upon whether a multicast transmission is successfully received during the multicast reception cycle. A terminal device may be configured to send an indication on whether a multicast transmission is successfully received or not. For example, a base station may be configured to skip the unicast reception cycle, in response to receiving an indication from the terminal device that the multicast transmission is successfully received during the multicast reception cycle. Skipping a unicast reception cycle may comprise, for example, cancelling a scheduled unicast transmission or terminating a started unicast transmission. Alternatively, a base station may be configured to schedule a transmission of new data for the unicast reception cycle in response to receiving an indication from the terminal device that the multicast transmission is successfully received during the multicast reception cycle. The base station may further be configured to transmit the scheduled unicast transmission in response to receiving an indication from the terminal device that the reception of multicast transmission is failed during the multicast reception cycle.

Figure 4 is a block diagram comprising a plurality of terminal devices 401 and a radio access network (RAN) 402. A terminal device 401 may be user equipment such as a computing device and a RAN may be an eNodeB or a gNodeB.

In the example of Figure 4, a terminal device 401 comprises one or more control circuitry, such as at least one processor, and at least one memory, including one or more algorithms such as a computer program instructions wherein the at least one memory and the computer program instructions are configured, with the at least one processor to cause the terminal device 401 to carry out any of the example functionalities described below.

The RAN 402 receives multicast data such as multimedia content and the plurality of terminal devices 401 are subscribed to the same multicast service. UE1 and UE2 are located such that they cannot be reached by a single radio beam. In such a situation, the RAN 402 may select unicast transmissions 403 for UE1 and UE2, and a multicast transmission 404 for the other UEs. However, it may be possible for UE2 to receive a multicast transmission with a probability lower than the multicast service requires.

Figure 5A and 5B illustrate example signalling diagrams depicting example embodiments. Figure 5A illustrates an embodiment in which a unicast transmission is scheduled before a multicast transmission. Figure 5B illustrates an embodiment in which a multicast transmission is scheduled before a unicast transmission.

In the example of Figure 5A, a scheduler is comprised by the apparatus 200 such as a base station. The scheduler receives multicast data from a data network. Multicast data may comprise, for example, multimedia content such as video content. The scheduler configures user equipment with a unicast reception cycle and a multicast reception cycle. The unicast reception cycle and the multicast reception cycle may comprise a discontinuous unicast reception cycle and a discontinuous multicast reception cycle. In the example of Figure 5A, the unicast reception cycle and the multicast reception cycle are configured such that they at least partially overlap and the unicast reception cycle precedes the multicast reception cycle.

The scheduler also sends information on corresponding data to the user equipment. Information on corresponding data may comprise, for example, an indication that the data comprised by a unicast transmission and the data comprised by a multicast transmission following the unicast transmission are the same.

The scheduler is configured to schedule a unicast transmission according to the unicast reception cycle and a multicast transmission according to the multicast reception cycle. In the example of Figure 5A, the scheduler transmits data scheduled over unicast using a unicast data radio bearer to the user equipment. The user equipment is configured to determine whether the unicast transmission is successfully received. Based on the determination whether the unicast transmission is successfully received, the user equipment may either receive the multicast transmission following the unicast transmission or skip the multicast reception cycle.

Similarly to the example of Figure 5A, in the example of Figure 5B, a scheduler comprised by the apparatus 200 receives multicast data from a data network. The scheduler configures user equipment with a multicast reception cycle and a unicast reception cycle. The multicast reception cycle and the unicast reception cycle may comprise a discontinuous multicast reception cycle and a discontinuous unicast reception cycle. In the example of Figure 5B, the multicast reception cycle and the unicast reception cycle are configured such that they at least partially overlap and the multicast reception cycle precedes the unicast reception cycle.

The scheduler also sends configuration information to the user equipment. The configuration information comprises an instruction to send a notification on whether the multicast transmission is successfully received. The configuration may also comprise additional configuration parameters. The scheduler is configured to schedule a multicast transmission according to the multicast reception cycle and a unicast transmission according to the unicast reception cycle. In the example of Figure 5B, the scheduler transmits data scheduled over multicast using a multicast data radio bearer to the user equipment. The user equipment is configured to send a notification on whether the multicast transmission is successfully received. Based on the notification whether the multicast transmission is successfully received, the scheduler may either skip the scheduled unicast reception cycle or transmit new data during the unicast reception cycle.

Figure 6 illustrates a method 600 incorporating aspects of the previously disclosed embodiments. More specifically, the example method 600 illustrates informing coordinating a first transmission and a second transmission. The method 600 may be performed by an access point such as a base station.

The method starts with scheduling 605 a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer. The first transmission may comprise a multicast transmission and the first data radio bearer may comprise a multicast radio bearer.

The method continues with scheduling 610 a second transmission of the multicast data according to a second reception cycle using a second data radio bearer. The second transmission may comprise a unicast transmission and the second data radio bearer may comprise a unicast radio bearer. The method further continues with coordinating 615 the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave. A reception cycle may comprise a time period comprising an active period and an inactive period. During the active period the terminal device is in an active state, for example, monitors PDCCH and, if indicated by PDCCH, receives data, and during the inactive period the terminal device is in an inactive state, for example, in a sleep state.

Figure 7 illustrates a method 700 incorporating aspects of the previously disclosed embodiments. More specifically, the example method 700 illustrates scheduling a first transmission and a second transmission such as a multicast transmission and a unicast transmission, respectively. The method 700 may be performed by an access point such as a base station.

The method starts with configuring 705 a terminal device with a first reception cycle using a first data radio bearer and a second reception cycle using a second data radio bearer. Configuring a terminal device may comprise providing the terminal device with one or more configuration parameters. The one or more configuration parameters may comprise parameters relating to a reception cycle such as a parameter defining a duration of an active period, duration of an inactive period and/or a number of subframes in the reception cycle. In the example of Figure 7, a terminal device is configured 705 with a multicast reception cycle using a multicast radio bearer and a unicast reception cycle using a unicast radio bearer.

The method continues with configuring 710 the terminal device to send a notification on a successful reception of a first transmission. The terminal may also be configured to send a notification on a failed reception of the first transmission. Configuring the terminal device to send a notification may also comprise other configuration parameters such as a definition of a format in which the notification is to be sent.

In the example of Figure 7, the terminal device is configured 710 to send a notification on whether the multicast transmission is successfully received by the terminal device.

The method further continues with scheduling 715 the first transmission and a second transmission. In the example of Figure 7, scheduling 715 a first transmission comprises scheduling a multicast transmission and scheduling second transmission comprises scheduling a unicast transmission. The method further continues with receiving 720 a notification from the terminal device whether the multicast transmission was successfully received.

The method further continues with determining 725, based on the received notification, whether the first transmission is successfully received. In the example of Figure 7, determining whether the first transmission is successfully received comprises determining whether the multicast transmission is successfully received. If the multicast transmission is successfully received, the base station skips the unicast reception cycle or transmits 730 new data during the configured unicast reception cycle. Skipping a scheduled transmission may comprise terminating a started transmission or not starting a scheduled transmission. On the other hand, if the multicast transmission is not successfully received, the base station transmits 735 the scheduled unicast transmission.

Figure 8 illustrates a method 800 incorporating aspects of the previously embodiments. More specifically, the example method 800 illustrates determining an operation to be performed. The method 800 may be performed by a terminal device.

The method starts with receiving 805 an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second radio bearer according to a second reception cycle. The first transmission may comprise a unicast transmission and the first data radio bearer may comprise a unicast data radio bearer. The second transmission may comprise a multicast transmission and the second data radio bearer may comprise a multicast data radio bearer. The indication may be received during the first reception cycle.

The indication that multicast data transmitted via the first data radio bearer correspond to the multicast data transmitted via the second data radio bearer may comprise an indication that the multicast data transmitted via the first DRB and the second DRB are the same.

The method continues with receiving 810 the multicast data via the first data radio bearer according to the first reception cycle. A reception cycle may comprise a time period comprising an active period and an inactive period. During the active period the terminal device is in an active state, for example, monitors and receives data, and during the inactive period the terminal device is in an inactive state, for example, in a sleep state.

The method continues with determining 815, based in the received indication and the received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle. The operation may comprise skipping the second reception cycle, in response to determining that the first transmission is successfully received or receiving the second transmission in response to determining that the first transmission is failed.

Figure 9 illustrates a method 900 incorporating aspects of the previously disclosed embodiments. More specifically, the example method 900 illustrates determining an operation to be performed. The method 900 may be performed by a terminal device.

The method starts with receiving 905 configuration information on a unicast reception cycle for a unicast data radio bearer and a multicast reception cycle for a multicast data radio bearer.

A reception cycle may comprise a time period comprising an active period and an inactive period. During the active period the terminal device is in an active state, for example, monitors and receives data, and during the inactive period the terminal device is in an inactive state, for example, in a sleep state. Configuration information may comprise parameters relating to a reception cycle such as a parameter defining a duration of an active period, duration of an inactive period and/or a number of subframes in the reception cycle.

The method continues with receiving 910 an indication of corresponding data of multicast content transmitted via a unicast data radio bearer and a multicast data radio bearer. An indication of corresponding data may comprise an indication that data transmitted via a unicast data radio bearer and a multicast data radio bearer are the same.

The method continues with receiving 915 multicast data via a unicast data radio bearer and determining 920 whether the unicast transmission is successfully received. If the unicast transmission is successfully received the terminal device may skip 925 the multicast reception cycle. If the unicast transmission is not successfully received, the terminal may receive a scheduled multicast transmission during the multicast reception cycle.

Without limiting the scope of the claims, an advantage of coordinating a first transmission and a second transmission such that a first reception cycle and a second reception cycle at least partially interleave may be that network resources may be used more efficiently. An advantage of indicating that the multicast data transmitted via a first DRB corresponds to the multicast data transmitted via a second DRB may be that transmission sessions may be dynamically optimized.

Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is that transmission sessions may be provided dynamically such that radio resources may be optimized while reducing battery consumption. Another technical effect of one or more of the example embodiments is that unnecessary network traffic may be reduced. As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside on the apparatus, a separate device or a plurality of devices. If desired, part of the software, application logic and/or hardware may reside on the apparatus, part of the software, application logic and/or hardware may reside on a separate device, and part of the software, application logic and/or hardware may reside on a plurality of devices. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer- readable media. In the context of this document, a 'computer-readable medium' may be any 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, with one example of a computer described and depicted in FIGURE 2. A computer-readable medium may comprise a computer-readable storage medium that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to with the at least one processor, cause the apparatus at least to: schedule a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer; schedule a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer; and coordinate the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

2. The apparatus according to claim 1, wherein a reception cycle comprises a time period comprising active period and an inactive period.

3. The apparatus according to claim 1 or 2, wherein the apparatus is further configured to send an indication to the terminal device that the multicast data transmitted via the first data radio bearer corresponds to the multicast data transmitted via the second data radio bearer.

4. The apparatus according to claim 3, wherein the apparatus is configured to send the indication during an active period of the first reception cycle.

5. The apparatus according to any of claims 3 or 4, wherein the indication comprises a reference to the first data radio bearer.

6. The apparatus according to any preceding claim, wherein the first data radio bearer comprises a multicast data radio bearer and the second data radio bearer comprises a unicast data radio bearer.

7. The apparatus according to any preceding claim, wherein the apparatus is configured to coordinate the first transmission and the second transmission such that the first reception cycle and the second reception cycle at least partially interleave, and the first reception cycle precedes the second reception cycle.

8. The apparatus according to any preceding claim, wherein the apparatus is further configured to, in response to receiving an indication that the first transmission is successfully received, skip the second reception cycle.

9. The apparatus according to any of claims 1-7, wherein the apparatus is configured to, in response to receiving an indication that the first transmission is successfully received, schedule a transmission of new data for the second reception cycle.

10. The apparatus according to any preceding claim, wherein the apparatus is a base station.

11. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to with the at least one processor, cause the apparatus at least to: receive an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer according to a second reception cycle; receive the multicast data via the first data radio bearer according to the first reception cycle; and determine, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

12. The apparatus according to claim 11, wherein the apparatus is configured to receive the indication during the first reception cycle.

13. The apparatus according to claim 11 or 12, wherein the first reception cycle comprises a unicast reception cycle and the second reception cycle comprises a multicast reception cycle.

14. The apparatus according to any of claims 11 to 13, wherein the apparatus is configured to skip the second reception cycle, in response to determining that the first transmission is successfully received.

15. The apparatus according to any of claims 11 to 13, wherein the apparatus is configured to receive a second transmission during the second reception cycle, in response to determining that the first transmission is failed.

16. A method comprising: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer; scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer; and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

17. A method comprising: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer; receiving the multicast data via the first data radio bearer according to the first reception cycle; and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.

18. A non-transitory computer readable medium comprising instructions for causing an apparatus to perform at least the following: scheduling a first transmission of multicast data to a terminal device according to a first reception cycle using a first data radio bearer; scheduling a second transmission of the multicast data to a terminal device according to a second reception cycle using a second data radio bearer; and coordinating the first transmission and the second transmission of the multicast data such that the first reception cycle and the second reception cycle at least partially interleave.

19. A non-transitory computer readable medium comprising instructions for causing an apparatus to perform at least the following: receiving an indication that multicast data transmitted via a first data radio bearer according to a first reception cycle corresponds to multicast data transmitted via a second data radio bearer; receiving the multicast data via the first data radio bearer according to the first reception cycle; and determining, based on the received indication and received multicast data via the first data radio bearer, an operation to be performed during the second reception cycle.