Mapping dual radio protocol stack data into a single transport block

Abstract

According to an example aspect, there is provided an apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving a transport block comprising data for at least one of a first radio protocol stack, or a second radio protocol stack, obtaining boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

Description

MAPPING DUAL RADIO PROTOCOL STACK DATA INTO A SINGLE TRANSPORT BLOCKFIELD

[0001] Various example embodiments relate to wireless communications.5BACKGROUND

[0002] For the design of Sixth Generation (6G) radio protocols, an approach was suggested in: Z. Li, E. Malkamaki, C. Rosa, B. Sebire “A novel approach to radio protocols design for 6G”, Nokia Bell Labs, 1 September 2023. Said approach relies on two radio0 protocol stacks; an anchor protocol stack (APS), for example, for low bitrate services and a fast protocol stack (FPS), for example, for high bitrate services. With such a dual stack approach, the complex mechanisms and optimizations that are fully justified for low bitrate services need not be used for very high bitrate services. However, with current schemes routing or mapping data to correct protocol stacks may be delayed or inefficient. 5

[0003] Therefore, there is a need for efficient routing of data to radio protocol stacks.SUMMARY

[0004] According to an aspect, there is provided the subject matter of the independent claims. Some embodiments are defined in the dependent claims.

[0005] According to a first aspect, there is provided an apparatus comprising at least0 one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:- receiving a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining boundary information defining a boundary between two data elements of5 the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and-routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

[0006] According to a second aspect, there is provided an apparatus comprising at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack, and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain.

[0007] According to a third aspect, there is provided a method comprising- receiving, by a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining, by the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and- routing, by the receiving apparatus, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

[0008] According to a fourth aspect, there is provided a method comprising:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two dataelements is to be processed, at the receiving apparatus, using a second processing chain.

[0009] According to a fifth aspect, there is provided a non-transitory computer readable medium having stored thereon instructions that, when executed by a computing device, cause the computing device to perform:- receiving a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and- routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

[0010] According to a sixth aspect, there is provided a non-transitory computer readable medium having stored thereon instructions that, when executed by a computing device, cause the computing device to perform:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain.

[0011] One or more examples of implementations are set forth in more detail in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 shows, by way of example, a network architecture of a communication system;

[0013] FIG. 2A shows, by way of example, radio protocols;

[0014] FIG. 2B shows, by way of example, radio processing units incorporated by different types of apparatuses;

[0015] FIG. 3 and FIG. 4 illustrate processes according to some embodiments;

[0016] FIG. 5 shows, by way of example, a transport block;

[0017] FIG. 6 shows, by way of examples, transport blocks;

[0018] FIG. 7A, 7B and 7C show, by way of examples, data field(s) of a transport block;

[0019] FIG. 8A and 8B show, by way of examples, transport blocks;

[0020] FIG. 9 shows, by way of example, a transport block;

[0021] FIG. 10 shows, by way of example, signalling between entities; and

[0022] FIG. 11 illustrates an apparatus according to some embodiments.EMBODIMENTS

[0023] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements

[0024] A “transport block” as to be understood in the context of the present disclosure, is or comprises data to be transmitted from one device, and to be received by another device. The transport block comprises a set of protocol data units (PDUs). At a transmission time interval (TTI), radio protocol stacks may deliver, to a medium access control (MAC) layer, a set of PDUs that are multiplexed into at least one transport block. Alternatively oradditionally, the MAC layer may deliver, to radio protocol stacks, at least a part of a set of PDUs that have been multiplexed into at least one transport block. A plurality of such transport blocks may be delivered within a given TTI. Transport block may also comprise MAC control elements (CEs), service data units (SDUs) comprising said PDUs, as well as padding. A transport block may comprise data for at least one of a first radio protocol stack or a second radio protocol stack. The contents of the transport block may be at least to an extent dependent on the use case and scenario. In other words, data for the first radio protocol stack or data for the second radio protocol stack may not necessarily be present in a transport block, if no data is to be processed by the first radio protocol stack or the second radio protocol stack.

[0025] A “boundary” is to be understood as a border, region or location that separates two adjacent or neighboring data elements or data bundles within a transport block. In other words, such a boundary is between two data elements of the transport block. “Granularity” refers to the level of detail and / or specificity at which data or data element may be collected, defined, analyzed, processed and / or stored. In some embodiments, the size and / or granularity of a boundary may be 1 bit. In some other embodiments, the size and / or granularity of the boundary may be larger than a bit. For example, the size and / or granularity of the boundary may be 1 byte or even more. In other words, the granularity of the boundary may be different depending on, for example, formation of a transport block and use case of such a transport block. A portion of data in the transport block processable using a processing chain may be understood as a “data element”. Such data elements may be processable with different processing chains. However, in certain scenarios a data element may be a portion of a transport block allocated to a processing chain yet fail to comprise data per se. There may be a plurality of boundaries within a transport block depending on the number of data elements, for example. Data elements may be, for example, portions of a transport block that are processable within a processing chain.

[0026] “Processing chain” is to be understood as a radio protocol stack or part thereof for processing data elements. Examples of processing chains include a first radio protocol stack and a second radio protocol stack. The second radio protocol stack may support a higher bitrate than the first radio protocol stack. The first radio protocol stack may host control plane functions, such as idle mode, connected mode and related configurations of the radio resource control (RRC). Further the first protocol stack may host optimizations for low bitrate services. The second radio protocol stack may be optimized for parallel processingusing radio processing units (RPUs) therein. In some instances, the second radio protocol stack may focus on user plane (UP) transfer for simplified design, especially when high bitrate may be needed. For example, the second radio protocol stack may focus on UP transfer and not focus on control plane functions. For example, all control plane functions may be included in the first radio protocol stack. On the other hand, the second radio protocol stack may be inactive when bitrate requirements are low. Processing chains include an anchor protocol stack (APS), a fast protocol stack (FPS) as well as RPUs comprised in a fast protocol stack (FPS), for example. Data elements may be processable with a processing chain, for example, an APS, wherein a boundary is defined between two data elements of a transport block, such as MAC control elements (CEs), signaling radio bearer (SRB), or user plane (UP) data elements for APS. Other examples of usage of the boundary are described below.

[0027] The first radio protocol stack may be referred to as an anchor protocol stack (APS), which is a radio protocol stack for low bitrate services (i.e., a radio protocol stack supporting only low bitrates). A low bitrate service may be defined as a service failing to support any bitrates higher than a pre-defined bitrate value. In other words, a low bitrate may be defined as a bitrate smaller than the pre-defined bitrate value. Said pre-defined bitrate value may be, for example, 1 Gbps (though, in practice, this may depend on application and UE capability, for example). Further, the APS may be configured for enabling wide coverage through bit-level optimization, for example. The APS may be configured to enable high reliability through radio link control (RLC) automatic repeat request (ARQ). For example, the first radio protocol stack may hold control plane and user plane for the apparatus, e.g. UE.

[0028] The second radio protocol stack may be referred to as a fast protocol stack (FPS), which is a radio protocol stack for high bitrate services (i.e., a radio protocol stack supporting at least high bitrates or higher bitrates than the first radio protocol stack supports). The FPS may comprise a processing-friendly and implementation-friendly design. A high bitrate service may be defined as a service supporting at least some bitrates higher than or equal to the pre-defined bitrate value (e.g. 1 Gbps). In other words, a high bitrate may be defined as a bitrate higher than or equal to the pre-defined bitrate value. Thus, the FPS is assumed to support at least some higher bitrates not supported by the APS. Fast protocol stack (FPS) utilizes radio processing units (RPUs), thereby enabling parallel processing of radio functions. The number of actual RPUs may differ depending on the apparatus inquestion and / or scenario and use case. For example, the second protocol stack may hold user plane for the apparatus, e.g. UE, and not control plane.

[0029] APS and FPS may be defined as in Z. Li, E. Malkamaki, C. Rosa, B. Sebire “A novel approach to radio protocols design for 6G”, Nokia Bell Labs, 1 September 2023 (section Protocol design), for example.

[0030] Even though terms “APS” and “FPS” are used in the present disclosure to refer to two (parallel) radio protocol stacks of different types, it is to be understood that other terms may be used, instead, to refer to two separate configurations of radio protocols and radio protocol stacks having at least one characteristic (e.g., supported highest bitrate) different from one another. The teachings of the present disclosure should, thus, not be construed to be limited to said two terms.

[0031] 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), Internet Protocol multimedia subsystems (IMS), rebel SIM (R- SIM) for code division multiple access (CDMA) technologies such as lx and lx evolution data optimized (IxEV-DO), global system for mobile communications (GSM) or any combination thereof.

[0032] FIG. 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 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 typically comprises also other functions and structures than those shown in FIG. 1.

[0033] 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.

[0034] The example of FIG. 1 shows a part of an exemplifying radio access network.

[0035] A communications system typically comprises more than one (e / g)NodeB 104 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 signaling purposes. The (e / g)NodeB is a computing device configured to control the radio resources of communication system it is coupled to. The 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. 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.

[0036] The user device 100, 102 (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 equipment may comprise a mobile equipment and at least one universal integrated circuit card (UICC).

[0037] The user device 100, 102 typically refers to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identity (or identification) module (SIM) or UICC, 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. Here, the SIM may be a physical SIM which may be removable by a user or anembedded SIM (eSIM) embedded directly into the user device 100, 102 (and thus not being removable by a user). 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. Thus, the user devices may not enable direct user interaction or may enable only limited user interaction (e.g., during setup). 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 terminal device, a subscriber unit, mobile station, remote terminal, access terminal, user terminal or user equipment (UE) just to mention but a few names or apparatuses. Each user device 100, 102 may comprise one or more antennas.

[0038] 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 ICT 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.

[0039] Additionally, although the apparatuses have been depicted as single entities, different units, processors and / or memory units (not all shown in FIG. 1) may be implemented.

[0040] 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. 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, 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 integrable 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-RI 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.

[0041] 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).

[0042] The communication system is also able to communicate with other networks, such as a public switched telephone network or the Internet 112, or utilize 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.

[0043] Edge cloud may be brought into the 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 unit (RU) 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 central or centralized unit, CU 108). Thus, in summary, the RAN may comprise at least one distributed access node comprising a central unit, one or more distributed units communicatively connected to the central unit and one or more (remote) radio heads or units, each of which is communicatively connected to at least one of the one or more distributed units.

[0044] It should also be understood that the distribution of labor between core network operations and base station operations may differ from that of the LTE or even be nonexistent. 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 nodeB (gNB). It should be appreciated that MEC can be applied in 4G networks as well.

[0045] 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 rail-way / maritime / aeronautical communications. Satellite communication may utilize 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.

[0046] 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 aplurality 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 or 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. Typically, 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.

[0047] 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. Typically, a network which is able to use “plug-and-play” (e / g)NodeBs, includes, in addition to Home (e / g)NodeBs (H(e / g)nodeBs), a home node B gateway, or HNB-GW (not shown in FIG. 1). A HNB Gateway (HNB-GW), which is typically installed within an operator’s network may aggregate traffic from a large number of HNBs back to a core network.

[0048] 6G architecture is targeted to enable easy integration of everything, such as a network of networks, joint communication and sensing, non-terrestrial networks and terrestrial communication. 6G systems are envisioned to encompass machine learning algorithms as well as local and distributed computing capabilities, where virtualized network functions can be distributed over core and edge computing resources. Far edge computing, where computing resources are pushed to the very edge of the network, will be part of the distributed computing environment, for example in “zero-delay” scenarios. 5G systems may also employ such capabilities. More generally, the actual (radio) communication system is envisaged to be comprised of one or more computer programs executed within a programmable infrastructure, such as general -purpose computing entities (servers, processors, and like).

[0049] An example of a dual stack approach comprising a first radio protocol stack 201 and a second radio protocol stack 202 is depicted in FIG. 2A. This dual stack approach may be supported by any of the terminal devices 100, 102 and the access node 104 of FIG. 1. In FIG. 2A, the first radio protocol stack 201 is an APS and the second radio protocolstack 202 is an FPS. As can be appreciated from FIG. 2A, the FPS comprises a plurality of RPUs. For example, in order to maximize the power saving gains enabled by the plurality of RPUs, the number of activated RPUs may be adjusted according to the need of instantaneous bitrate or load. The concatenation or segmentation of internet protocol (IP) packets into fixed / variable size packet data convergence protocol (PDCP) PDUs may be performed at a higher layer PDCP (PDCP -HI). Lower layer PDCP (PDCP -LOW) may apply encryption, ciphering and / or integrity protection to PDCP PDUs. At a TTI, by request of a lower layer MAC (MAC -LOW) for example, the first and second radio protocol stacks (APS 201 and FPS 202 of FIG. 2A, respectively) deliver to lower layer MAC (MAC -LOW) a set of PDUs that may be multiplexed in a transport block. The transport block may then be passed to the physical layer (PHY) for processing.

[0050] In FIG. 2B, there are shown three different apparatuses 210, 220 & 230 (e.g. UEs) comprising different arrangements of radio protocol stacks, and optionally RPUs therein. Namely, FIG. 2B illustrates a simplistic apparatus 210 supporting only APS, a moderately capable and complex apparatus 220 supporting both the APS and the FPS with three RPUs and a highly capable and high-complexity apparatus 230 supporting the APS and the FPS with five RPUs. In general, the higher the (largest) bitrate that a given apparatus is able to support, the more RPUs may be contained in the FPS of the apparatus. Each of the apparatuses 210, 220 & 230 may be a terminal device (e.g., a terminal device 100, 102 of FIG. 1) or a part thereof or an access node (e.g., an access node 104 of FIG. 1) or a part thereof. For simplicity, the radio protocol stacks of the apparatuses 210, 220 & 230 are illustrated in FIG. 2B but it is understood by a person skilled in the art that an apparatus may comprise additional parts and / or elements.

[0051] An apparatus according to some embodiments may be a terminal device (e.g., a terminal device 100, 102 of FIG. 1) or a part thereof or an access node (e.g., an access node 104 of FIG. 1) or a part thereof. At least some apparatuses according to embodiments, may implement the APS without being configured to utilize the FPS, possibly removing the need to introduce the equivalent of machine type communication (MTC), narrowband intemet- of-things (NB-IoT) and / or reduced capability (RedCap) devices. The apparatus 210 of FIG. 2B is one example of such a simplistic apparatus. Some apparatuses, such as apparatuses 220 and 230 of FIG. 2B, may implement both stacks, i.e., both APS and FPS. The higher the bitrates the apparatus supports, the larger the number of RPUs, the FPS of said apparatus may typically comprise.

[0052] In order to enable parallel processing of data, apparatuses according to embodiments, such as the terminal devices 100, 102 and the access node 104 of FIG. 1, may be configured to route (or map) portions of a received transport block to appropriate and / or suitable radio protocol stacks, for example a first radio protocol stack and a second radio protocol stack, such as APS and FPS, respectively. This may be accomplished, for example, by reading a medium access control (MAC) header or MAC subheader for each service data unit (SDU) of the received transport block. However, such an approach may be time consuming and inefficient as a MAC header and / or a MAC subheader corresponding to data for a processing chain may first need to be located and processed within the received transport block before portion(s) of the received transport block can be routed to said processing chain, such as the APS and / or the FPS. Therefore, substantial delays may occur. These delays may be especially pronounced for the APS when a large number of MAC headers or MAC subheaders needs to be processed (that is, when a large number of data elements for the FPS, and RPUs therein, are present). This may occur, for example, when a high data rate service is used. Transport block MAC subheaders for all RLC SDUs for the FPS may need to be processed before any data relating to the APS can be processed.

[0053] The embodiments to be discussed below overcome or alleviate all or at least some of the problems indicated above relating to routing of data elements of a transport block to different (parallel) processing chains, such as a first radio protocol stack and a second radio protocol stack, for example, APS and / or FPS, respectively. At least some embodiments of the present disclosure provide parallelizable routing for different processing chains, thereby alleviating at least some of the above-mentioned problems. At least some embodiments introduce boundary information depicting boundaries between two data elements, such that different portions, or segments of a transport block may be distinguished.

[0054] FIG. 3 illustrates an example process according to at least some embodiments of the present disclosure. The process of FIG. 3 may be carried out, for example, by a terminal device such as one of the terminal devices 100, 102 of FIG. 1, or by an access node, such as access node 104 of FIG. 1. The apparatus carrying out the process FIG. 3 may be one of the apparatuses 210, 220, 230 of FIG. 2B. In the following, the entity carrying out the process of FIG. 3 is called an apparatus for simplicity. The process of FIG. 3 may correspond to downlink (DL) communication scenario (in which case the apparatus may be a terminal device) or to an uplink (UL) communication scenario (in which case the apparatus may be an access node).

[0055] Referring to FIG. 3, the apparatus receives, in step 301, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack. The second radio protocol stack may support higher bitrates compared to the first radio protocol stack. Examples of a first radio protocol stack and a second radio protocol stack include an APS and an FPS, respectively. Data for APS may be referred to as APS data and data for FPS may be referred to as FPS data. The FPS data may comprise data for one or more RPUs of the FPS. The transport block may be received, for example, from an access node.

[0056] In some embodiments, the first radio protocol stack may be a radio protocol stack hosting control plane functions and / or (bit-level) optimization (e.g., for low bitrate services). Additionally or alternatively, the second radio protocol stack may be a radio protocol stack configured to enable parallel processing, for example, using one or more RPUs (e.g., for high bitrate services).

[0057] In some embodiments, the transport block may be received, in step 301, from a transmitting apparatus. The transmitting apparatus may be, e.g., a terminal device (if the apparatus carrying out the process of FIG. 3 is an access node) or an access node (if the apparatus carrying out the process of FIG. 3 is a terminal device).

[0058] The apparatus obtains, in step 302 of FIG. 3, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain. The two data elements, between which is said boundary, may be for at least one of a first radio protocol stack or a second radio protocol stack, such as an APS or an FPS, respectively. In other words, the boundary may be a boundary between first and second data elements, where the first data element is to be processed using a first radio protocol stack or a second radio protocol stack, and the second data element is to be processed using the first radio protocol stack or the second radio protocol stack (that is, the same or different radio protocol stack compared to the first data element). For example, the first data element may be a first APS data element and the second data element may be a second APS data element. Examples of APS data elements include MAC CEs, SRB and UP data. As another example, the first data element may be a first FPS data element and the second data element may be a second FPS data element. As a further example, the first data element may be an APS data element andthe second data element may be an FPS data element. As a further example, the first data element may be an FPS data element and the second data element may be an APS data element. As a further example, the first data element may be data for the first radio processing unit and the second data element may be data for the second radio processing unit (examples of FIG. 8 A and FIG. 8B).

[0059] The boundary information defines, explicitly or at least implicitly, the boundary between two data elements within a transport block. The boundary information may comprise information directly defining the boundary and / or it may contain information based on which the boundary may be discerned or determined (using possibly also further information such as one or more pre-defined properties of the transport block). The first and second processing chains may be parallel processing chains. The first processing chain may comprise an RLC entity and the second processing chain may comprise an RLC entity. Such an RLC entity may be comprised in a first radio protocol stack and / or second radio protocol stack, such as an APS and / or an FPS, or such an RLC entity may be comprised in an RPU of the second radio protocol stack, such as an FPS.

[0060] In some embodiments, the obtaining of the boundary information in step 302 may comprise receiving the transport block from the transmitting apparatus (transmitting apparatus transmitted the transport block).

[0061] The obtaining of the boundary information, as in step 302 of the process described in FIG. 3, may be conducted in a plurality of different ways. For example, the obtaining of the boundary information may comprise receiving boundary information as a separate message or as a part of the transport block. In general, the obtaining of the boundary information (step 302) may occur after the transmitting of the transport block (step 301) as shown in FIG. 3, before the transmitting of the transport block (step 301), or alternatively, the transmitting of the transport block (step 301) and obtaining of the boundary information (step 302) may occur concurrently such that, for example, the boundary information is part of the transport block. As such, the step 301 and step 302, may occur in an order different from the one depicted in FIG. 3 in at least some embodiments.

[0062] Referring to FIG. 3, the apparatus routes, in step 303, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain. In other words, the apparatus may route at least some of the data on one side of the boundary to one of the first processing chain or the second processingchain and at least some of the data on other side of the boundary to other one of the first processing chain or the second processing chain.

[0063] In FIG. 4, there is provided a process according to at least some embodiments. The process of FIG. 4 may be carried out, for example, by a terminal device such as one of the terminal devices 100, 102 of FIG. 1, or by an access node, such as access node 104 of FIG. 1. The apparatus carrying out the process FIG. 4 may be one of the apparatuses 210, 220, 230 of FIG. 2B. In the following, the entity carrying out the process of FIG. 4 is called an apparatus for simplicity. The process of FIG. 4 may correspond to downlink (DL) communication scenario (in which case the apparatus may be an access node) or to an uplink (UL) communication scenario (in which case the apparatus may be terminal device).

[0064] The process of FIG. 4, also involves a receiving apparatus, which may be, depending on the communication scenario, an access node, such as the access node 104 of FIG. 1 or a terminal device such as one of the terminal devices 100, 102 of FIG. 1. Typically, for example, for a terminal device as the apparatus, the receiving apparatus may be an access node. Conversely, for example, for an access node, such as gNB, as the apparatus, the receiving apparatus may be a terminal device.

[0065] The receiving apparatus may be an apparatus configured to carry out the process of FIG. 3 in parallel with the execution of the process of FIG. 4 at the present apparatus. Consequently, any of the definitions and features described above in connection with FIG. 3 may apply, mutatis mutandis, also here.

[0066] Referring to FIG. 4, in step 401, the apparatus transmits, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack. The first radio protocol stack may support a low bitrate than the second radio protocol stack. For example, the first radio protocol stack may be an APS and the second radio protocol stack may be an FPS. Data for an APS may be known as APS data and data for an FPS may be known as FPS data.

[0067] Then, the apparatus transmits, in step 402, boundary information defining a boundary between two data elements of the transport block. Here, a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain, as described also in connection with FIG. 3.

[0068] While in FIG. 4 the boundary information is transmitting in step 402 following the transmission of the transport block in step 401, the order of steps 401, 402 may differ from this in other embodiments. In general, the boundary information may be transmitted to the receiving apparatus before the transmission of the transport block, as a part of the transmission of the transport block (the boundary information forming a part of the transport block), or after the transmission of the transport block. In other words, step 402 may precede step 401, or alternatively in some embodiments, step 401 and step 402 may occur concurrently, or substantially concurrently.

[0069] In the succeeding paragraphs, the boundary information, the transport block, and the boundary as described above in connection with the processes of FIG. 3 and FIG. 4, is described in further detail according to some embodiments in connection with FIGs. 5, 6, 7 A, 7B, 7C, 8 A, 8B, 9 & 10.

[0070] Boundary information defines at least a boundary between two data elements of the transport block, in other words, between a first data element and a second data element of the transport block. In some embodiments, the transport block may comprise data for the first radio protocol stack and the second radio protocol stack, wherein the first data element is a data element for the first radio protocol stack and the second data element is a data element for the second radio protocol stack. In some embodiments the first radio protocol stack may support lower bitrate than the second radio protocol stack. In some embodiments, the first radio protocol stack may be an APS, and the second radio protocol stack may be an FPS. In some embodiments, the transport block comprises FPS data, such that the first data element of the transport block is an FPS data element for a first RPU of the FPS, and the second data element of the transport block is an FPS data element for a second RPU of the FPS. In some embodiments the transport block comprises APS data, and the first data element is a first APS data element and the second data element is a second APS data element. In some embodiments, the transport block comprises only APS data or only FPS data. As such, the boundary between a first data element and a second data element depends at least in part on the transport block and data therein.

[0071] For example, boundary information may comprise information on the number of physical resource blocks, PRBs, such as the number of PRBs for data to be processed by the first radio protocol stack, such as the APS (being, e.g. 5 bits). In some embodiments, the boundary information may comprise data length of data element(s) within the transportblock. Data length may be given as a number of bytes or bits. In some embodiments, the boundary information may comprise information on the number of bytes for a data element or number of bytes for a plurality of data elements, such as first data element and second data element, for example, data elements to be processed by the first radio protocol stack, such as the APS and / or the second radio protocol stack, such as the FPS. In some embodiments, the boundary information may comprise information explicitly defining a location of a boundary within the transport block, for example. It is understood by a person skilled in the relevant art, that the granularity of a boundary information defining a boundary between two data elements may depend on the embodiment, and construction of the transport block. The granularity may define the number of bits used to convey boundary information. In some embodiments, the boundary information may be conveyed using 1 bit. Alternatively, the boundary information may be conveyed using more than 1 bit, such as using 1 byte.

[0072] In the following, one example of boundary information defining the boundary between two data elements is described. In the example, the transport block comprises data for the first radio protocol stack, such as the APS and data for the second radio protocol stack, such as the FPS, or for example, at least reserved physical resource blocks, for such data. For a transport block with a size of 3000 bytes, the length of data for the first radio protocol stack, such as APS, may be 952 bytes, and the rest of the size of the transport block, in other words 2048 bytes (i.e., 3000 bytes - 952 bytes = 2048 bytes) may be the length of data for the second radio protocol stack, such as FPS. Therefore, the boundary information may, for example, define a boundary between data for the first radio protocol stack and data for the second radio protocol stack, based on the length of the data for the first radio protocol stack (952 bytes), or length of the data for the second radio protocol stack (2048 bytes), or both. By knowing the total size of the transport block and at least one of: the length of data for the first radio protocol stack or the length of data for the second radio protocol stack, an apparatus may determine (or identify) the different portions or segments of the transport block. The apparatus may then route the different portions or segments to a suitable processing chain (i.e., to a suitable radio protocol stack providing the suitable processing chain) or to a plurality of suitable processing chains (i.e., to one or more suitable radio protocol stacks providing the plurality of suitable processing chains).

[0073] Another example of the boundary information is provided in the following. In the example, the transport block comprises data for a first radio protocol stack, such as APS and data for the second radio protocol stack, such as FPS, or at least reserved data segmentfor such data. For a transport block with a size of 3000 bytes, length of data for first radio protocol stack may be reserved to be 247 bytes. In accordance with the example, it may further be defined that a single RPU of the second radio protocol stack may generate, at maximum, data with length of 1024 bytes. Boundary information may in such an example define a boundary between data element for the first radio protocol stack and data element for the second radio protocol stack, but also that the data element for the second radio protocol stack further comprises data elements for three RPUs of the second radio protocol stack, the three data elements having respective lengths 1024 bytes, 1024 bytes and 704 bytes.

[0074] The boundary information as well as obtaining and / or transmitting thereof depend on the embodiment. For example, in some embodiments, the boundary information is part of a transport block, while, in some other embodiments, the boundary information is a separate message or is a part of a separate message (i.e., comprised in a separate message).

[0075] FIG. 5 illustrates an example of an embodiment, wherein the boundary information is comprised in a message 550 separate from a transport block 500. FIG. 5 depicts a transport block 500, and a separate message 550 comprising boundary information, where the transport block 500 comprises a data element 510 processable with FPS 515 (i.e., said data element comprises FPS data 510) and a data element 520 processable with APS 525 (i.e., said data element comprises APS data 520) as well as a boundary 555 in between. In the example of FIG. 5, the separate message 550 comprising the boundary information is a DL grant message. The DL grant message may be, for example, a downlink control information (DCI) message.

[0076] Depending on the context, for example, depending on the type of the device receiving the transport block and the boundary information (being, e.g., a UE or an access node) and / or transmission direction (being, e.g., downlink or uplink,), the separate message may be of a different type compared to FIG. 5. For example, in an uplink communication scenario, an apparatus, such as an access node, may receive the separate message as a part of a buffer status report (BSR). Such a separate message therefore defines a boundary within a transport block received by the apparatus (e.g., access node). In another example of an uplink communication scenario, an apparatus, such as a terminal device, may receive the separate message as a part of a UL grant message transmitted by an access node. The separate message may then be used by the apparatus, such as a terminal device, to form a transportblock. Therefore, in some embodiments, the separate message may be transmitted in the opposite direction to that of the transport block. In other words, the separate message may be transmitted as a DL communication, and transport block may be transmitted as a UL communication.

[0077] As stated above, in some embodiments, in an uplink communication scenario, the separate message may be part of a B SR or a UL grant. However, in some embodiments, the BSR may comprise preliminary information to that of the boundary information. For example, the preliminary information comprised in BSR may define a boundary, or a desired boundary, between two data elements within a transport block, and / or the BSR may comprise preliminary information regarding available data for transmission from a first radio protocol stack and a second radio protocol stack of the terminal device. In such embodiments, the terminal device transmits the BSR that comprises preliminary information to the access node. The access node may then form, based on the BSR and preliminary information therein, boundary information, and transmit said boundary information to the terminal device, for example as a DCI message, or part thereof. The terminal device then transmits, to the access node, a transport block conforming to the boundary information formed by the access node. Then, after receiving the transport block from the terminal device, the access node may route, based on the boundary information, data comprised in the transport block.

[0078] In some embodiments, the boundary information, e.g. comprised in the separate message, may comprise a length (or size) of data for the first radio protocol stack, such as APS, in a DCI message. In such embodiments, the inclusion of the length of data for the first radio protocol stack, such as APS, in the boundary information may cause additional overhead when compared to the inclusion of the number of PRBs, but additional potential padding process may be avoided. For example, in a scenario wherein 4.5 units of PRBs within a transport block are occupied by data for APS, the length of data comprised in the separate message may define the length to be 4.5 units of PRBs (e.g., length of PRBs in bits). Conversely, the number of PRBs may define the number of PRBs occupied by the data for the APS would be 5 PRBs. Therefore, in the example provided, the additional potential padding of 0.5 PRBs may be avoided when using the length of data instead of the number of PRBs.

[0079] In some embodiments, the boundary information, e.g. comprised in the separate message, may comprise a length (or size) of data for the second radio protocol stack,such as FPS. In some embodiments, the boundary information, e.g. comprised in the separate message, may comprise a length (or size) of data for the first radio protocol stack and a length (or size) of data for the second radio protocol stack.

[0080] In some embodiments, the boundary information is a part of a transport block. Therefore, in such embodiments, the transmission and / or reception of transport block comprises the transmission and / or reception of the boundary information. For example, MAC header(s), MAC subheader(s), or MAC control element(s) of the transport block may comprise boundary information, in some embodiments.

[0081] FIG. 6, illustrates two alternative transport blocks 600A and 600B according to some embodiments. Each of the two transport blocks 600A and 600B comprises, at the beginning of the transport block 600A, 600B, a MAC (sub)header 650A, 650B comprising boundary information. The transport block 600A of FIG. 6 comprises a first data element 610A processable with FPS (i.e., a data element comprising FPS data) and, following the first data element 610A, a second data element 620A processable with APS (i.e., a data element comprising APS data) as well as a boundary 655A therebetween. The transport block 600B of FIG. 6 comprises a first data element 610B processable with APS (i.e., a data element comprising APS data) and, following the first data element 610B, a second data element 620B processable with FPS (i.e., a data element comprising FPS data) as well as a boundary 655B therebetween. In other embodiments, the boundary information may be comprised in a MAC control element (CE), or plurality thereof, for example.

[0082] As can be appreciated from FIG. 6, the first data element 610A,610B and the second data element 620A,620B may be defined in multiple different ways in different embodiments. Therefore, as can be appreciated from FIG. 6 showing two alternative transport blocks 600A, 600B, the relative order of FPS and APS data may differ, depending on the transport block 600 A, 600B. A person skilled in the art also appreciates that such different order is not merely for embodiments wherein the boundary information is comprised in a transport block, but also for at least some embodiments wherein the boundary information is obtained (FIG. 3), or transmitted (FIG. 4), as a separate message.

[0083] In some embodiments, the boundary information may comprise or consist of a data length field (or a data size field). FIG. 7 A illustrates two octets (“Oct 1” and “Oct 2” in FIG. 7A) comprised in a data length field of a transport block. Typically, an octet may also be referred to as a byte. Said two octets may correspond to a beginning of said transportblock such as to an initial field of a MAC protocol data unit (PDU). In FIG. 7A, the boundary information comprises the data length field 751 A. In FIG. 7A, the data length field 751 A comprising the two octets depicts length of APS data in the transport block.

[0084] In some embodiments, the presence of a data length field may be indicated using a data length field indicator. The data length field indicator may be known also as an indication field. The indication field may indicate the presence of boundary information, such as the presence of the data length field within a transport block (or specifically within, e.g., a MAC header or MAC subheader of the transport block). The indication field may have a length of 1 bit, or 1 byte, or more than 1 byte, for example. In at least some embodiments, such indication fields are comprised in a transport block (i.e., form a part of the transport block itself). Such indication fields may be applicable for processes according to at least some embodiments such processes disclosed in FIG. 3 and / or FIG. 4.

[0085] FIG. 7B illustrates three octets (“Oct 1”, “Oct 2” and “Oct 3” in FIG. 7B) comprised in a data length field 75 IB of a transport block. Said three octets may correspond to a beginning of said transport block such as to an initial field of a MAC protocol data unit (PDU). In FIG. 7B, the transport block comprises an APS data length field 75 IB comprising information on the length of data for APS (i.e., length of APS data). Additionally, the transport block of FIG. 7B comprises an APS data length field presence indicator (APSI) 740B indicating a presence or existence of the APS data length field 75 IB. The APSI 740B may be comprised in a MAC header or a MAC subheader, for example.

[0086] Additionally or alternatively (not shown in FIG. 7B), the transport block may comprise an FPS data length field comprising information on the length of data for FPS (i.e., length of FPS data) and an FPS data length field presence indicator indicating a presence or existence of the FPS data field(s). The FPS data length field indicator, FPSI) may be contained in a MAC header or a MAC subheader.

[0087] In some embodiments, any of the data length field indicators discussed above may have, for example, a size of one byte, as is depicted for APSI 740B in FIG. 7B. Such a data length field indicator 740B (for example, APSI, or FPSI) may then be utilized to describe the presence of a data length field 75 IB, and / or number of octets in the data length field length field within a transport block. A MAC header or a MAC subheader comprising such data length field indicator may then be decoded such that the length of data for APS and / or length of data for FPS is obtained. For example, according to at least someembodiments, when the APSI is equal to ‘O’, APS data length field is assumed to not exist within the transport block. In this example, any other value, e.g. ‘1’, or values of the APSI may indicate that the APS data length field exists in the transport block.

[0088] In some embodiments, the data length field indicator (for example, APSI or FPSI) may be 1 bit in size. FIG. 7C illustrates two octets (“Oct 1” and “Oct 2” in FIG. 7C) of a transport block, for example at the beginning of said transport block. In FIG. 7C, the APSI 740C is comprised in “Oct 1” octet of the transport block together with a part of an APS data length field 751C. The octet “Oct 2” of FIG. 7C comprises another part of the APS data length field 751C. In some embodiments, the data length field indicator 740C may at least describe the presence of a data element for a processing chain, for example data for APS, and / or data for FPS. Such an embodiment is depicted in FIG. 7C, wherein APSI of 1 bit is shown. In some embodiments where APSI field has size of 1 bit, the data length field indicator 740C with said bit set to ‘0’ may indicate that corresponding data (i.e., APS data in FIG. 7C) is absent, while ‘ 1’ may indicate that such corresponding data is present. The indication field, for example the data length field indicator 740C, such as APSI and / or FPSI, may be at the beginning of the transport block, or beginning of a MAC PDU, such as a first or initial field of a MAC PDU, for example a “Reserved” field of a MAC PDU. For example, in 5G, “Reserved” field in 5G MAC subheader may be used as a data length indicator field 740B,740C, such as APSI or FPSI.

[0089] It should be noted that, while FIGs. 7A, 7B & 7C show examples where the data length field or the combination of the data length field and the data length indicator has the size of two octets (or bytes), in other embodiments, the size of the data length field may differ from this value. For example, the size of the data length field or the combination of the data length field and the data length indicator may be one octet, three octet or more than three octets.

[0090] Boundary information, such as the boundary information described in processes of FIG. 3 and FIG. 4, may be used to define boundaries between N data elements of a transport block, wherein N is an integer greater than two, such as 3, 10, or 100. In such embodiments, the boundary information may define lengths of 7V-1 portions (or parts or sections) of a transport block. In some embodiments, a transport block may comprise N data elements for at least one of APS or FPS (i.e., the N data elements may comprise one or more APS data elements and / or one or more FPS data elements). In such a case, the boundaryinformation may define A-l boundaries, each of said V-1 boundaries being between two neighboring data elements of the N data elements.

[0091] In some embodiments wherein N data elements and N-l boundaries between said N data elements are comprised in a transport block, boundary information may be comprised in a single position, such as in one MAC header, or a MAC subheader. FIG. 8A and FIG. 8B illustrate a transport block 800A and a transport block 800B, respectively. Both transport blocks 800A, 800B comprise a plurality of data elements and plurality of boundaries. More specifically FIG. 8 A and 8B depict embodiments wherein N=3. In other words, the transport block of FIG. 8 A comprises boundary information 850, and three data elements 810A, 821 A and 822A, and the transport block of FIG. 8B comprises boundary information 851, 852, and three data elements 810B, 821B and 822B.

[0092] FIG. 8A illustrates an embodiment wherein boundary information 850 is located at the beginning, or near the beginning, of the transport block 800A, such as in a MAC (sub)header located, for example, at the beginning of the transport block 800A. As can be appreciated from FIG. 8A, such boundary information 850 defines a plurality of boundaries 854, 856. In some embodiments, the boundary information may be comprised in a MAC header or a MAC subheader, and the boundary information may comprise data lengths of N or at least N-l data elements of the N data elements in the transport block.

[0093] In the case of FIG. 8A such boundaries are a boundary 854 between APS data 810 and data for a first radio processing unit RPU #1 of FPS 821 A, as well as a boundary 856 between the data for the first radio processing unit, RPU #1, of FPS 821A and data for a second radio processing unit, RPU #2, of FPS 822A. At least some embodiments wherein boundary information is comprised in the beginning of a transmission block may be beneficial for, for example, parallel processing. Such embodiments may be beneficial because boundary information may be obtained for all suitable boundaries such that data may be routed concurrently, or substantially concurrently, to suitable processing chains. This may enable parallel processing of data from the transport block.

[0094] In some embodiments, such as the one illustrated in FIG. 8B, wherein N data elements and N-l boundaries between said N data elements are comprised in a transport block, the boundary information may be comprised in A-l sections (or data elements or fields) of the transport block, for example in A-l MAC headers or A-l MAC subheaders of the transport block. Each section containing boundary information defining a boundarybetween two data elements may (directly) precede said two data elements (or equally precede first of said two data elements). In some embodiments, the boundary information is comprised in TV- 1 MAC headers or TV- 1 MAC subheaders of the transport block. In FIG. 8B, there is provided an embodiment, wherein boundary information is comprised in a plurality of sections 851, 852 of a transport block 800B. Specifically, FIG. 8B corresponds to an example where N is equal to 3.

[0095] Referring to FIG. 8B, the boundary information 851 located before APS data 810, defines a boundary 855 between APS data 810B and data for the first radio processing unit RPU #1 of FPS 821B. The boundary information 852 at, or near, boundary 855 defines the boundary 857 between the first radio processing unit, RPU #1, of FPS 821B and data for a second radio processing unit, RPU #2, of FPS 822B. As can be appreciated from FIG. 8B, such boundary information 851, 852 defines altogether a plurality of boundaries 855, 857. In the case of FIG. 8B such boundaries are a boundary 855 between APS data 810B and data for a first radio processing unit RPU #1 of FPS 821B, as well as a boundary 857 between the data for the first radio processing unit, RPU #1, of FPS 82 IB and data for a second radio processing unit, RPU #2, of FPS 822B.

[0096] It is to be understood, that such boundaries provided in the transport block 800 A of FIG. 8 A or transport block 800B of FIG. 8B, are examples, and other types of data elements and boundaries are applicable as well. For example, more than two data elements for a plurality of radio processing units, RPUs, of FPS may be comprised in a transport block for which boundary information defines a plurality of boundaries. In another example, data elements within APS data, such as control elements (CEs), MAC CEs, signaling radio bearer (SRB) and user plane (UP), and boundaries thereof may be applicable according to at least some embodiments.

[0097] According to some embodiments, the boundary information may be, or be part of, a separate message. The separate message may be, or be a part of, for example, a DL grant, a UL grant, a B SR or a DCI message depending on the embodiment. In some embodiments, the boundary information may be a part of a radio resource control RRC, configuration message. In some embodiments, such an RRC configuration message comprising boundary information may be received or transmitted before the reception or transmission of the transport block during, for example, processes of FIG. 3 and FIG. 4, respectively. In at least some embodiments utilizing a boundary information comprised in aseparate message, such as the RRC configuration message, the transport block may comprise a reserved data field for APS and a reserved data field for FPS. Further, said separate message, such as the RRC configuration message, may comprise boundary information for such reserved data fields for APS and FPS, for example, as a data length of said reserved data fields. Therefore, in some embodiments, length and / or size of data elements within a transport block may be explicitly pre-defined. In some embodiments, the transport block may comprise data for the APS and the FPS, such that a first data element is an APS data element and a second data element is an FPS data element. In some further embodiments, the boundary information comprised in the RRC configuration message comprises a data length of a data field reserved for APS data and / or a data length of a data field reserved for FPS data. In other words, the transport block, such as transport block of FIG. 8, may comprise a reserved data field for data for APS and a reserved data field for data for FPS. In some embodiments, the boundary information in the RRC configuration message may be defined to be specific to at least one carrier frequency and / or at least one frequency resource, such as when a plurality of transport blocks are generated in a transmission time interval (TTI).

[0098] FIG. 9 depicts a transport block 900, such as the transport block described in processes of FIG. 3 and FIG. 2, the transport block 900 comprising a first data element 910 (e.g., APS data) and a second data element 920 (e.g., FPS data). The first data element 910 is processable with a first processing chain 915 (e.g., APS) and the second data element 920 is processable with a second processing chain 925 (e.g., FPS). Embodiments, such as that depicted in FIG. 9, may use reserved portions for the first data element 910 and the second data element 920. For example, the portions may have fixed or pre-defined sizes or the size of the portions may be given as percentages of the total size of the transport block. In some embodiments, the pre-defined portions may be dependent on the size of the transport block, be a ratio of data for APS and data for FPS with respect to the transport block. The ratio may be a pre-defined ratio within the granted resources. The reserved data field(s) may be, for example 30% of a granted resource for data for APS and 70% of a granted resource for data for FPS. Granted resource may be a transport block or a portion thereof. Such embodiments may be beneficial in that transport blocks may be easily processed and routed based on the boundary information. Further such boundary information, may be usable for a plurality of transport blocks with said pre-defined reserved data field(s) for data elements. In at least some embodiments, the boundary information, and the construction of a transport block itcorresponds to, may be configured based on for example a ratio of the data elements to be processable with different processing chains, such as APS and FPS. For example, data length for APS and data length for FPS within a transport block may be reserved. Such reserved data length may be based on, for example, a ratio of data for APS and data for FPS with respect to the granted resources of a transport block. By knowing the total size of the transport block and at least one of the ratio of data for the first radio protocol stack or the ratio of data for the second radio protocol stack, an apparatus may determine the different portions or segments of the transport block. The apparatus may then route the different portions or segments to a suitable processing chain (i.e., to a suitable radio protocol stack providing the suitable processing chain) or to a plurality of suitable processing chains (i.e., to one or more suitable radio protocol stacks providing the plurality of suitable processing chains).

[0099] While, in the above embodiments, the data contained in the received transport block was routed based on the received boundary information, in some other embodiments, a transport block to be transmitted may be generated or formed based on received boundary information. FIG. 10 illustrates signaling between a first apparatus and a second apparatus according to one such embodiment. The first apparatus 1001 may be an access node, such as access node 104 of FIG. 1 (e.g. gNB), and the second apparatus 1002 may be a terminal device, for example, a terminal device 100, 102 of FIG. 1 (e.g. UE). The apparatus 1002 carrying out some of the processes of FIG. 10 may be one of the apparatuses 210, 220, 230 of FIG. 2B.

[0100] Referring to FIG. 10, the first apparatus 1001 transmits, in message 1010, boundary information (as a separate message) to the second apparatus 1002. The boundary information may be defined as described in connection with any of the previously discussed embodiments. The second apparatus 1002 receives, in block 1011, said boundary information. According to an uplink communication scenario, said separate message may further comprise a UL grant. Based on the boundary information, the second apparatus 1002 forms or generates, in block 1015, transport block for transmission to the first apparatus 1001. After the transport block has been formed, the second apparatus 1002 transmits 1020 said transport block to the first apparatus 1001, and the first apparatus 1001 receives, in block 1021, said transport block. After the first apparatus 1001 has received the transport block, the first apparatus 1001 routes, in block 1030, data from the transport block based on the boundary information. A benefit of such an embodiment is that, as the transmitted transportblock has been formed based on instructions received from the first apparatus 1001, transmission delays may be minimized. Any of the features or definitions discussed above, for example, in conjunction with FIG. 3 or FIG. 4, may apply, mutatis mutandis, also here.

[0101] FIG. 11 provides an apparatus 1101 according to some embodiments. Specifically, FIG. 11 may illustrate an apparatus 1101 being a terminal device or an access node.

[0102] The apparatus 1101 may comprise one or more communication control circuitry 1120, such as at least one processor, and at least one memory 1130, including one or more algorithms 1131 (instructions), such as a computer program code (software) wherein the at least one memory 1130 and the computer program code (software) are configured, with the at least one processor, to cause the apparatus 1101 to carry out any one of the exemplified functionalities of the apparatus described above. Said at least one memory 1130 may also comprise at least one database 1132.

[0103] When the one or more communication control circuitry 1120 comprises more than one processor, the apparatus 1101 may be a distributed device wherein processing of tasks takes place in more than one physical unit. Each of the at least one processor may comprise one or more processor cores. A processing core may comprise, for example, a Cortex-A8 processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices Corporation. The one or more communication control circuitry 1120 may comprise at least one Qualcomm Snapdragon and / or Intel Atom processor. The one or more communication control circuitry 1120 may comprise at least one application-specific integrated circuit (ASIC). The one or more control circuitry 1120 may comprise at least one field-programmable gate array (FPGA).

[0104] Referring to FIG. 11, the one or more communication control circuitry 1120 of the apparatus 1101 are configured to carry out functionalities of the apparatus described above by means of any of FIGs. 2A, 2B, 3 to 6, 7A, 7B, 7C, 8A, 8B, 9 and 10 using one or more individual circuitries. It is also feasible to use specific integrated circuits, such as ASIC (Application Specific Integrated Circuit) or other components and devices for implementing the functionalities in accordance with different embodiments.

[0105] Referring to FIG. 11, the apparatus 1101 may further comprise different interfaces (I / F) 1110 such as one or more communication interfaces comprising hardwareand / or software for realizing communication connectivity according to one or more communication protocols. The one or more communication interfaces 1110 may comprise, for example, at least one communication interface between the apparatus 1101 and a blockchain. If the apparatus is a terminal device, the one or more communication interfaces 1110 may comprise at least one communication interface between the apparatus 1001 and at least one access node. If the apparatus is an access node, the one or more communication interfaces 1110 may comprise at least one communication interface between the apparatus 1101 and at least one terminal device.

[0106] The one or more communication interfaces 1110 may comprise standard well- known components such as an amplifier, filter, frequency-converter, (de)modulator, and encoder / decoder circuitries, controlled by the corresponding controlling units, and one or more antennas. The apparatus 1101 may also comprise one or more user interfaces.

[0107] If the apparatus 1101 is a terminal device, the apparatus 1101 may comprise one or more user input devices and / or interfaces for connecting one or more user input devices.

[0108] Referring to FIG. 11, the memory 1130 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.

[0109] 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 (and / or firmware), 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 terminal device or an access node, to perform various functions, and (c) hardware circuit(s) and 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 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 aportion of a hardware circuit or processor and its (or their) accompanying software and / or firmware.

[0110] In an embodiment, at least some of the processes described in connection with FIGs. 3, 4, 5, 6, 7A, 7B, 7C, 8A, 8B, 9 & 10 may be carried out by an apparatus comprising corresponding means for carrying out at least some of the described processes. Some example means for carrying out the processes may include at least one of the following: detector, processor (including dual-core and multiple-core processors), digital signal processor, controller, receiver, transmitter, encoder, decoder, memory, RAM, ROM, software, firmware, display, user interface, display circuitry, user interface circuitry, user interface software, display software, circuit, filter (low-pass, high-pass, bandpass and / or bandstop), sensor, circuitry, inverter, capacitor, inductor, resistor, operational amplifier, diode and transistor. In an embodiment, the at least one processor, the memory, and the computer program code form processing means or comprises one or more computer program code portions for carrying out one or more operations according to any one of the embodiments of FIGs. 3, 4, 5, 6, 7A, 7B, 7C, 8 A, 8B, 9 & 10 or operations thereof. In some embodiments, at least some of the processes may be implemented using discrete components.

[0111] According to an embodiment, there is provided an apparatus (e.g., a terminal device or an access node) comprising means for performing:- receiving a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and-routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

[0112] According to an embodiment, there is provided an apparatus (e.g., a terminal device or an access node) comprising means for performing:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain.

[0113] Embodiments as described may also be carried out, fully or at least in part, in the form of a computer process defined by a computer program or portions thereof. Embodiments of the methods described in connection with FIGs. 3, 4, 5, 6, 7A, 7B, 7C, 8A, 8B, 9 & 10 may be carried out by executing at least one portion of a computer program comprising corresponding instructions. The computer program may be provided as a computer readable medium comprising program instructions stored thereon or as a non- transitory computer readable medium comprising program instructions stored thereon. The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. For example, the computer program may be stored on a computer program distribution medium readable by a computer or a processor. The computer program medium may be, for example but not limited to, a record medium, computer memory, readonly memory, electrical carrier signal, telecommunications signal, and software distribution package, for example. The computer program medium may be a non-transitory medium. Coding of software for carrying out the embodiments as shown and described is well within the scope of a person of ordinary skill in the art.

[0114] The term “non-transitory”, as used herein, is a limitation of the medium itself (that is, tangible, not a signal) as opposed to a limitation on data storage persistency (for example, RAM vs. ROM).

[0115] It is to be understood that the embodiments disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. Itshould also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0116] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

[0117] As used herein, a plurality of items, structural elements, compositional elements, and / or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations.

[0118] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that an embodiment can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of embodiments.

[0119] While the forgoing examples are illustrative of the principles of the embodiments in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the embodiments. Accordingly, it is not intended that the embodiments be limited, except as by the claims set forth below.

[0120] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular form, throughout this document does not exclude a plurality.INDUSTRIAL APPLICABILITY

[0121] At least some embodiments find industrial application in wireless communications.ACRONYMS LISTARQ automatic repeat requestAPS anchor protocol stackAPSI APS data length indicator fieldCN core networkCU centralized unitDU distributed unitFPS fast protocol stackMAC medium access controlMTC machine type communicationNB-IoT narrow-band internet-of-thingsPDU protocol data unitPRB Physical resource blockRLC radio link controlRPU radio processing unitRRC radio resource controlRU radio unitNVF network function virtualizationSDN software defined networkingSDU service data unitREFERENCE SIGNS LIST

Claims

CLAIMS:

1. An apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:- receiving a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and- routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

2. The apparatus according to claim 1, wherein the second radio protocol stack is a radio protocol stack supporting higher bitrates compared to the first radio protocol stack.

3. The apparatus according to claim 1 or claim 2, wherein the first radio protocol stack is an anchor protocol stack, APS; and the second radio protocol stack is a fast protocol stack, FPS.

4. The apparatus according to any one of claims 1 to 3, wherein the transport block comprises the data for the first radio protocol stack and the second radio protocol stack, and the first data element is a data element for the first radio protocol stack and the second data element is a data element for the second radio protocol stack.

5. The apparatus according to claim 2 or claim 3, wherein the transport block comprises at least the data for the second radio protocol stack; and wherein the first data element is a data element for a first radio processing unit, RPU, of the second radio protocol stack; and the second data element is a data element for a second RPU of the second radio protocol stack.

6. The apparatus according to claim 2 or claim 3, wherein the transport block comprises at least the data for the first radio protocol stack; and wherein the first data element is a first data element for the first radio protocol stack; and the second data element is a second data element for the first radio protocol stack.

7. The apparatus according to any one of the preceding claims, wherein the boundary information comprises a data length of at least one of: the first data element; or the second data element.

8. The apparatus according to any one of claims 1 to 6, wherein the boundary information comprises a number of physical resource blocks, PRBs, in at least one of: the first data element; or the second data element.

9. The apparatus according to any one of claims 1 to 6, wherein the boundary information comprises number of bytes in at least one of: the first data element; or the second data element.

10. The apparatus according to any one of preceding claims, wherein the obtaining of the boundary information comprises receiving the boundary information as a part of the transport block.

11. The apparatus according to claim 10, wherein the boundary information is or is a part of one of a medium access control, MAC, header, a MAC subheader or a MAC control element, CE, of the transport block.

12. The apparatus according to claim 10 or claim 11, wherein the transport block comprises an indication field indicating a presence of the boundary information.

13. The apparatus according to claim 12, wherein the boundary information comprises a data length field defining a data length of at least one of the first data element or the second data element, and the indication field indicates a presence of the data length field.

14. The apparatus according to claim 12 or claim 13, wherein the indication field has a length of 1 bit or 1 byte.

15. The apparatus according to any one of claims 12 to 14, wherein the indication field is an initial field of a MAC protocol data unit, PDU.

16. The apparatus according to any one of claims 12 to 15, wherein the indication field is a Reserved field of a MAC PDU.

17. The apparatus according to any one of claims 1 to 9, wherein the obtaining of the boundary information comprises receiving the boundary information as a separate message or as a part thereof.

18. The apparatus according to claim 17, wherein the separate message is a downlink control information, DCI, message.

19. The apparatus according to claim 17, wherein the separate message is a buffer status report, BSR.

20. The apparatus according to claim 17, wherein the separate message is a radio resource control, RRC, configuration message, the reception of the RRC configuration message occurring before the reception of the transport block.

21. The apparatus according to claim 20, wherein the transport block comprises the data for the first radio protocol stack and the second radio protocol stack; and wherein the first data element is a data element for the first radio protocol stack; the second data element is a data element for the second radio protocol stack; and the boundary information comprised in the RRC configuration message comprises a data length of a data field reserved for data for the first radio protocol stack and / or a data length of a data field reserved for data for the second radio protocol stack.

22. The apparatus according to claim 21, wherein the boundary information is defined, in the RRC configuration message, to be specific to at least one carrier frequency and / or at least one frequency resource.

23. The apparatus according to any one of the preceding claims, wherein the transport block comprises an indication that the transport block comprises data for the first radio protocol stack and / or the second radio protocol stack and / or an indication that the transport block fails to comprise data for the first radio protocol stack or data for the second radio protocol stack.

24. The apparatus according to any one of the preceding claims, wherein the transport block is received from an access node as a downlink transmission.

25. The apparatus according to any one of claims 1 to 23, wherein the transport block is received from a terminal device as an uplink transmission.

26. The apparatus according to any one of the preceding claims, wherein the transport block comprises N data elements for at least one of first radio protocol stack or second radio protocol stack, and wherein the boundary information defines A-l boundaries, each of said A-l boundaries being between two neighboring data elements of the N data elements, wherein TV is an integer greater than 2.

27. The apparatus according to claim 24, wherein the boundary information is comprised in a MAC header or a MAC subheader, and the boundary information comprises data lengths of N or at least A-l data elements of the N data elements in the transport block.

28. The apparatus according to claim 26, wherein the boundary information is comprised in A-l MAC headers or M l MAC subheaders of the transport block.

29. An apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two dataelements is to be processed, at the receiving apparatus, using a second processing chain.

30. The apparatus according to claim 29, wherein the second radio protocol stack is a radio protocol stack supporting higher bitrates compared to the first radio protocol stack.

31. The apparatus according to claim 29 or claim 30, wherein the first radio protocol stack is an anchor protocol stack, APS; and the second radio protocol stack is a fast protocol stack, FPS.

32. The apparatus according to any one of claims 29 to 31, wherein the transport block comprises the data for the first radio protocol stack and the second radio protocol stack, and the first data element is a data element for the first radio protocol stack and the second data element is a data element for the second radio protocol stack.

33. The apparatus according to claims 30 or claim 31, wherein the transport block comprises at least the data for the second radio protocol stack; and wherein the first data element is a data element for a first radio processing unit, RPU, of the second radio protocol stack; and the second data element is a data element for a second RPU of the second radio protocol stack.

34. The apparatus according to any one of claims 29 to 31, wherein the transport block comprises at least the data for the first radio protocol stack; and wherein the first data element is a first data element for the first radio protocol stack; and the second data element is a second data element for the first radio protocol stack.

35. The apparatus according to any one of claims 29 to 34, wherein the boundary information comprises a data length of at least one: of the first data element; or the second data element.

36. The apparatus according to any one of claims 29 to 34, wherein the boundary information comprises a number of physical resource blocks, PRBs, in at least one of the first data element; or the second data element.

37. The apparatus according to any one of claims 29 to 34, wherein the boundary information comprises number of bytes in at least one of: the first data element; or the second data element.

38. The apparatus according to any one of claims 29 to 37, wherein the transmitting of the boundary information comprises transmitting the boundary information as a part of the transport block.

39. The apparatus according to claim 38, wherein the boundary information is or is a part of one of a medium access control, MAC, header, a MAC subheader or a MAC control element, CE, of the transport block.

40. The apparatus according to claim 38 or claim 39, wherein the transport block comprises an indication field indicating a presence of the boundary information.

41. The apparatus according to claim 40, wherein the boundary information comprises a data length field defining a data length of at least one of the first data element or the second data element, and the indication field indicates a presence of the data length field.

42. The apparatus according to claim 40 or claim 41, wherein the indication field has a length of 1 bit or 1 byte.

43. The apparatus according to any one of claims 40 to 42, wherein the indication field is an initial field of a MAC protocol data unit, PDU.

44. The apparatus according to any one of claims 40 to 43, wherein the indication field is a Reserved field of a MAC PDU.

45. The apparatus according to any one of claims 29 to 37, wherein the transmitting of the boundary information comprises transmitting the boundary information as a separate message or as a part thereof.

46. The apparatus according to claim 45, wherein the separate message is a downlink control information, DCI, message.

47. The apparatus according to claim 45, wherein the separate message is a buffer status report, BSR.

48. The apparatus according to claim 45, wherein the separate message is a radio resource control, RRC, configuration message, the transmission of the RRC configuration message occurring before the transmission of the transport block.

49. The apparatus according to claim 48, wherein the transport block comprises the data for the first radio protocol stack and the second radio protocol stack, the first data element is a data element for the first radio protocol stack, the second data element is a data element for the second radio protocol stack, and the boundary information comprised in the RRC configuration message comprises a data length of a data field reserved for data for the first radio protocol stack and / or a data length of a data field reserved for data for the second radio protocol stack.

50. The apparatus according to claim 49, wherein the boundary information is defined, in the RRC configuration message, to be specific to at least one carrier frequency and / or at least one frequency resource.

51. The apparatus according to any one of claims 29 to 50, wherein the transport block comprises an indication that the transport block comprises data for the first radio protocol stack and / or data for the second radio protocol stack and / or an indication that the transport block fails to comprise data for the first radio protocol stack or data for the second radio protocol stack.

52. The apparatus according to any one of claims 29 to 51, wherein the receiving apparatus is an access node.

53. The apparatus according to any one of claims 29 to 51, wherein the receiving apparatus is a terminal device.

54. The apparatus according to any one of claims 29 to 53, wherein the transport block comprises N data elements for at least one of the first radio protocol stack or the second radioprotocol stack, and wherein the boundary information defines A-l boundaries, each of said A-l boundaries being between two neighboring data elements of the N data elements, wherein TV is an integer greater than 2.

55. The apparatus according to claim 54, wherein the boundary information is comprised in a MAC header or a MAC subheader, and the boundary information comprises data lengths of N or at least A-l data elements of the N data elements in the transport block.

56. The apparatus according to claim 54, wherein the boundary information is comprised in A-l MAC headers or M l MAC subheaders of the transport block.

57. A method comprising:- receiving, by a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack;- obtaining, by the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and- routing, by the receiving apparatus, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

58. A method comprising:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a first radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain.

59. A non-transitory computer readable medium having stored thereon instructions that, when executed by a computing device, cause the computing device to perform:- receiving a transport block comprising data for at least one of a first radio protocol stack, or a second radio protocol stack;- obtaining boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed using a first processing chain and a second data element of the two data elements is to be processed using a second processing chain; and- routing, based on the boundary information, the data of the transport block to at least one of the first processing chain or the second processing chain.

60. A non-transitory computer readable medium having stored thereon instructions that, when executed by a computing device, cause the computing device to perform:- transmitting, to a receiving apparatus, a transport block comprising data for at least one of a radio protocol stack or a second radio protocol stack; and- before, as a part of or after the transmitting of the transport block, transmitting, to the receiving apparatus, boundary information defining a boundary between two data elements of the transport block, wherein a first data element of the two data elements is to be processed, at the receiving apparatus, using a first processing chain and a second data element of the two data elements is to be processed, at the receiving apparatus, using a second processing chain.

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