Methods and apparatus for communication networks

Abstract

To provide a method and device for optimizing a data stream with end-to-end.SOLUTION: A device 100 receives a plurality of cyclic data stream parameters cp#1, 2 and related QoS requirements QoS#1, 2, wherein at least one of the plurality of stream parameters characterizes arrival of a cyclic data stream and a related communication endpoint frame related to a communication network CN, receives first capability information ci1#1 to 3 for characterizing the capabilities of respective wired links, receives second capability information ci2#4, 5 for characterizing the capabilities of respective radio links, determines a preschedule on the basis of the plurality of cyclic data stream parameters, the related QoS requirements, the first network capability information and the second capability information, and constitutes network entities NE#1 to 6 of the communication network CN on the basis of the determined preschedule.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and apparatus for a communication network.

Background Art

[0002] In Industry 4.0, wireless communication is advancing on a large scale into factory sites. By introducing a highly flexible network and vertical integration into factories, future manufacturing will be extremely customizable and efficient.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, as a price for such flexibility, network management becomes complex. This is especially true when strict QoS requirements need to be met, such as in many industrial real-time applications. In wired communication systems such as TSN (Time-Sensitive Networking), end-to-end service guarantees such as limited latency are achieved by scheduling each user and applying a traffic shaping mechanism (e.g., time-aware shaping).

Means for Solving the Problems

[0004] The problems of the prior art are solved by the method according to claim 1 and the apparatus according to further claims.

[0005] According to a first aspect of this specification, the method includes: receiving a plurality of cyclic data stream parameters and associated QoS requirements, wherein at least one of the plurality of stream parameters characterizes at least one frame arrival of an associated cyclic data stream and an associated communication endpoint of a communication network; receiving first capability information characterizing the capability of each wired link of the communication network; receiving second capability information characterizing the capability of each wireless link of the communication network; determining a preschedule based on the plurality of cyclic data stream parameters, associated QoS requirements, the first network capability information, and the second capability information; and configuring at least one network entity of the communication network based on the determined at least one preschedule.

[0006] Advantageously, appropriate prescheduling is determined on a heterogeneous network consisting of wired TSNs and wireless networks. Different constraints are given by each system, and this approach allows each data stream to be optimized end-to-end.

[0007] An advantageous embodiment is characterized in that the prescheduling determination includes the steps of sequentially selecting at least one segment of a communication network based on first network capability information and second capability information, and determining at least one preliminary instance of the prescheduling for one of the selected segments of the communication network based on a plurality of cyclic data stream parameters and relevant QoS requirements associated with the first segment.

[0008] Advantageously, network segments allow for faster prescheduling compared to calculating the prescheduling for the entire network at once.

[0009] An advantageous embodiment is characterized in that the first selected segment includes a wireless link or a wired link, and the second segment includes a wired link or a wireless link.

[0010] Conveniently, this distinction can be determined by the characteristics of each link.

[0011] An advantageous embodiment is characterized in that the selection of a first selection segment includes the steps of determining a plurality of current usages related to wired and wireless links based on provided first and second capability information, and determining a first selection segment that includes a plurality of connected links among links whose related current usages exceed a usage threshold.

[0012] When a network segment is under heavy real-time cross-traffic load, it becomes a communication network bottleneck for the end-to-end cyclic data streams being considered, so an optimized prescheduling for this segment for low latency is determined first.

[0013] An advantageous embodiment is characterized in that the selection of a first selection segment includes the steps of determining a plurality of bandwidths of wired and wireless links based on provided first and second capability information, and determining a first selection segment that includes a plurality of connected links whose associated bandwidth is below a bandwidth threshold.

[0014] If one network segment has significantly less available bandwidth than the rest of the communication network, optimizing resource efficiency is beneficial to prevent other users from starving it up.

[0015] An advantageous embodiment is characterized in that the prescheduling includes at least one gate control list associated with a network entity that provides service to at least one wired link of a communication network.

[0016] Advantageously, at least one gate control list is determined by relying on second capability information that characterizes the capabilities of each radio link in the communication network.

[0017] A favorable embodiment is characterized in that the prescheduling includes at least a predicted cyclic traffic volume per hour and per radio link for a scheduler entity configured to schedule at least one network entity that provides service to at least one radio link of a communication network.

[0018] Advantageously, the predicted cyclic traffic volume per hour and per wireless link is determined by a first capability information that characterizes the capabilities of each wired link.

[0019] An advantageous embodiment is characterized in that the prescheduling includes at least one gate control list for at least one wired link of a network translator entity, and a predicted hourly, per-radio-link cyclic traffic volume for a scheduler entity configured to schedule the network translator entity to service at least one of the radio links associated with the network translator entity.

[0020] Advantageously, network translator entities are centrally pre-scheduled via pre-scheduling.

[0021] A second aspect of this specification provides an apparatus having the following configuration: receiving means for receiving a plurality of cyclic data stream parameters and associated QoS requirements, wherein at least one of the plurality of stream parameters characterizes the arrival of an associated cyclic data stream and at least frames of an associated communication endpoint of a communication network; receiving means for receiving first capability information characterizing the capability of each wired link of the communication network; receiving means for receiving second capability information characterizing the capability of each wireless link of the communication network; determining means for determining a prescheduling based on the plurality of cyclic data stream parameters, associated QoS requirements, the first network capability information, and the second capability information; and configuring means for configuring at least one network entity of the communication network based on the determined prescheduling.

[0022] An advantageous embodiment is characterized in that the decision means for determining the prescheduling comprises: selection means for sequentially selecting at least one segment of a communication network based on first network capability information and second capability information; and decision means for determining at least one preliminary instance of the prescheduling for one of the selected segments of the communication network based on a plurality of cyclic data stream parameters and relevant QoS requirements associated with the first segment.

[0023] An advantageous embodiment is characterized in that the first selected segment includes a wireless link or a wired link, and the second segment includes a wired link or a wireless link.

[0024] An advantageous embodiment is characterized in that the selection of a first selection segment includes the steps of determining a plurality of current usages associated with wired and wireless links based on provided first and second capability information, and determining a first selection segment that includes a plurality of connected links among links whose associated current usages exceed a usage threshold.

[0025] An advantageous embodiment is characterized in that the selection means for selecting the first selection segment includes a determination means for determining a plurality of bandwidths of wired and wireless links based on the provided first and second capability information, and a determination means for determining a first selection segment including a plurality of connected links among the links whose associated bandwidth is below the bandwidth threshold value.

[0026] An advantageous embodiment is characterized in that the preschedule includes at least one gate control list associated with a network entity that provides services to at least one wired link of a communication network.

[0027] An advantageous embodiment is characterized in that the preschedule includes at least a predicted cyclic traffic volume per time unit and per wireless link for a scheduler entity configured to schedule at least one network entity that provides services to at least one wireless link of a communication network.

[0028] An advantageous embodiment is characterized in that the preschedule includes a gate control list for at least one wired link of a network translator entity and a predicted cyclic traffic volume per time unit and per wireless link for a scheduler entity configured to schedule a network translator entity that provides services to at least one wireless link associated with the network translator entity.

[0029] Another aspect of this specification is directed to the use of the method according to the first aspect or the use of the apparatus according to the second aspect.

Brief Description of the Drawings

[0030] [Figure 1] It is a schematic diagram of a communication network and an apparatus for determining a preschedule of the communication network. [Figure 2] This is a schematic flowchart. [Figure 3] This is a schematic flowchart. [Figure 4] This is a schematic flowchart. [Figure 5] This is a schematic diagram of the packets for each cyclic data stream. [Modes for carrying out the invention]

[0031] Figure 1 schematically shows a communication network CN and a device 100 for determining prescheduled PS for the communication network CN. The exemplary communication network CN consists of a TSN and a 5G-based TSN network entity.

[0032] The device 100 includes receiving means (102) for receiving a plurality of cyclic data stream parameters cp#1, cp#2 and associated QoS requirements QoS#1, QoS#2. At least one of the plurality of stream parameters cp#1, cp#2 characterizes at least the frame arrival of the associated cyclic data stream, the associated frame size, and the associated communication endpoints App#1, App#2, App#i of the communication network CN. Endpoints App#1, App#2, App#i represent real-time applications, such as industrial control applications, running on or directly linked to one of each of the network entities NE#1-6 of the communication network CN.

[0033] The device 100 includes receiving means or a receiving interface (104) for receiving first capability information ci1#1-3 that characterizes the capabilities of each wired link l1, l2, and l3 of the communication network CN.

[0034] The device 100 includes receiving means (106) for receiving second capability information ci2#4-5 that characterizes the capabilities of each of the radio links l3 and l5 of the communication network CN.

[0035] For example, capability information ci2 is information about the current channel state for each user or network entity NE#4-6. This information can be considered in end-to-end scheduling. For instance, scheduling longer time slots can achieve better resilience to higher and more inconsistent resource requests from users, even in the event of a failed channel state.

[0036] The first and second capability information c1#1-3, c2#4-5 include static or dynamic parameters that describe the corresponding characteristics of a link or network entity of the communication network CN.

[0037] The device 100 includes a determination means (108) for determining a prescheduled PS based on a plurality of cyclic data stream parameters cp#1, cp#2, associated QoS requirements QoS#1, QoS#2, first network capability information ci1#1-3, and second capability information ci2#4-5.

[0038] The device 100 includes configuration means (110) for configuring at least one network entity SCHED#1,NE#1-6 of the communication network CN based on at least one determined prescheduled PS. In one example, configuration 110 includes transmitting at least a portion of the prescheduled PS.

[0039] A prescheduled PS includes at least one gate control list associated with network entities NE#1-4 that serve at least one of the wired links l1, l2, and l3 of the communication network CN. Prioritization of data transmissions is performed at the egress ports of each network entity NE#1-4 that serve each wired link l1-l3. Transmissions are determined based on the transmission selection algorithm TSA. When data is selected from a particular queue, the corresponding gate is opened and the data is transmitted. Gate open events are determined by the gate control list. Thus, coordination between different data streams is ensured, a protection window is provided, and high-priority data is guaranteed access to the network at a given moment. Transmissions of specific traffic classes are permitted for specific periods.

[0040] For example, a prescheduled PS includes at least an estimated cyclic traffic volume per hour and per radio link l4, l5 for a scheduler entity SCHED#1 configured to schedule at least one network entity NE#4-6 that serves at least one of the radio links l4, l5 of the communication network CN. Thus, the scheduler entity SCHED#1 can exclusively pre-reserve a quantity of radio resources to schedule packets related to a pre-scheduled cyclic data stream online.

[0041] For example, a prescheduled PS includes a gate control list for at least one wired link l3 of a network entity NE#4, specifically called a network translator, and a predicted cyclic traffic volume per hour and per wireless link l4, l5 for a scheduler entity SCHED#1. The scheduler entity SCHED#1 is configured to schedule the network translator entity NE#4 to serve at least one of the wireless links l4, l5 associated with the network translator entity NE#4. The at least one gate control list is used by the network entity NE#4 that serves the wired link l3.

[0042] The logical bridge concept means that network segment seg#2 represents a single TSN node. Therefore, individual 5G nodes NE#4-6 also have translators that function as external TSN nodes. Consequently, network entities NE#5 and NE#6 also have translators to applications App#1, 2, and 3 (although in this case, links to the applications are not scheduled, and therefore they have no scheduling functionality).

[0043] To find the optimal schedule for end-to-end cyclic data streams on a heterogeneous network, all streams on the network entities must be collectively optimized. The network is a time-triggered system, and based on a common time shared among all network entities, the transmission time of each frame can be precisely triggered at endpoint applications and all network entities.

[0044] Scheduling can be broadly divided into two classes. The first class is frame-based scheduling. For each frame arriving at a network entity, the scheduler determines when to schedule that frame. This type of scheduling is called "online scheduling." The second class, for example for industrial applications where communication is performed in deterministic cycles, provides a pre-scheduled scheduling plan (PS) that includes resources, based on knowledge of frame arrivals, before each frame arrives at the network entity. Because pre-scheduling is determined in advance, this is called "offline scheduling." This explanation will focus on the latter, pre-configured scheduling, known as "pre-scheduled PS."

[0045] The provided framework offers users or applications a set of transmit time offsets as part of a prescheduled PS that determines which network nodes must reserve resources for which frames. This setting may be translated into, or include, the respective gate control lists of TSN network entities or the respective resource allocations of the 5G system. In 5G systems, due to channel uncertainty, such pre-configured schedules are not determined at a low level (i.e., the reservation of a single resource element at the physical layer). Therefore, a two-stage approach is employed. First, based on a reasonable estimate of the channel, a prescheduled PS is determined to reserve each time slot. Next, the online scheduler SCHED#1 determines the precise resource allocation at the physical layer at a per-frame level.

[0046] This concept is also adopted in the system framework of TSN bridges and 5G virtual bridges, as shown in Figure 6. In a TSN system, the gate control list can be determined by an end-to-end scheduler directly scheduling each frame. In the case of 5G, first, a pre-scheduled PS contains a schedule based on an approximation of available transmit resources. Then, this pre-scheduled PS is used by the online 5G MAC scheduler as scheduler SCHED#1 to allocate specific resources on the radio link. Such end-to-end scheduling requires bridge capability information and configuration of available interfaces. In the case of TSN bridges and network translator entities, the gate control list is determined externally. The network translator entity applies the gate control list to the bridge's egress port via a remote configuration protocol.

[0047] Advantageously, the latency and bitrate per user and per cyclic data stream remain constant over time, and prescheduling can be calculated based on this. An example implementation would be to expose capability information for a 5GS bridge in the sense of a network translator entity. This information, including buffer status, link quality, serviced users, and experienced latency, would be available to the TSN-AF (TSN Application Function) and exposed via existing connections to an external TSN network control plane. In another example, UE-specific parameters such as latency within the UE (between the DS-TT and UE AN), latency from the UE to the NW-TT, propagation latency and other latency, channel / link quality, packet latency budget, and QoS flow could be reported from the UE and sent to the TSN-AF, or measured between the DS-TT and NW-TT. These values ​​are reported to the TSN-AF, which then transmits them to the TSN network. The scheduler could then be located, for example, outside the TSN-AF.

[0048] For example, TSCAI (TSC Assistance Information) is sent from the core network (CN) to the gNB in ​​the sense of scheduler SCHED#1. The transmission order of the former is from TSN-AF to the session management function (SMF), and then to the gNB in ​​the sense of scheduler SCHED#1. The TSN-AF is responsible for acquiring PSFP (IEEE 802.1Q) and creating containers for each stream or multiple streams. The SMF adds QoS flow and burst periodicity and sends the container to the gNB.

[0049] The SMF maps bursts / periodicities arriving from the TSN clock to the 5G clock. The User Plane Function (UPF) then updates the SMF by updating the cumulative rate ratio (rateRatio) if there is a mismatch. Based on the latter value, the SMF corrects the TSCAI and sends it back to the gNB.

[0050] According to one embodiment, capability information includes at least one of the following delay measurements: 5GS independentDelayMin, independentDelayMax, and txPropagationDelay.

[0051] Furthermore, reporting to 5GS in the sense of the scheduler entity SCHED#1 includes the following: - After establishing a PDU session, report the bridge information of the 5GS bridge in the sense of a network translation entity to the TSN network. - For time-aware and efficient scheduling, map TSN stream requirements obtained from the TSN network to 5GS QoS information (e.g., 5QI, TSC support information, etc.) of the corresponding PDU session's QoS flow. - The capabilities of a 5GS bridge as defined in 802.1Qcc (5GS bridge delay per traffic class and per port pair (frame size dependent and independent, and their maximum and minimum values: independentDelayMax, independentDelayMin, dependentDelayMax, dependentDelayMin), including ingress port number, egress port number and traffic class, and / or per port propagation delay (txPropagationDelay) including transmit propagation delay and egress port number).

[0052] TSN-AF is responsible for receiving bridge information from 5GS to 5GS bridges, and for registering or updating this information in the TSN network.

[0053] In one example, device 100 is located outside the TSN-AF and is connected to the TSN-AF via an interface from the outside. The TSN-AF is also connected internally to NW-TT (Network-Side TSN Translator).

[0054] In one example, device 100 is divided into two parts: one part is inside the TSN-AF and connected to an external TSN network segment; and the second part of device 100 is located outside the TSN-AF and connected to the internal part. The connection is located between the CNC (Centralized Network Configuration) and the TSN-AF.

[0055] The communication network CN is considered jointly. As the network size increases, this can become a computationally intensive task. Therefore, problem relaxation and heuristic methods can be used to find solutions within a feasible computation time. Furthermore, by applying the optimization target to different network segments, the problem set can be reduced and network-specific characteristics can be taken into account, as illustrated below.

[0056] Figure 2 shows a schematic flowchart of step 108 of Figure 1. The determination means is provided for reading the first and second capability information (202). For example, the first and second capability information includes at least one of the following: node capability, which includes the current state of each node, and link capability, which includes the current state of each link.

[0057] The decision means for determining the prescheduling comprises a selection means (204) that sequentially selects at least one segment of the communication network based on first network capability information and second capability information. Thus, selection 204 represents the selection of a subnetwork segment. The idea is to divide the network into segments of subnetworks that are iteratively optimized. This can significantly speed up the calculation of feasible solutions that may not be globally optimal. At least one of the selected network segments exhibits different characteristics from the rest of the network. This may be because the underlying network technology of the segment is different, or because it is affected by current traffic.

[0058] For example, the first selected segment, seg#2, includes a wireless link, and the second segment, seg#1, includes a wired link.

[0059] In another example, the first selection segment, seg#3, is chosen because the current usage of links l3 and l4 is above average.

[0060] In yet another example, the first selected segment, seg#3, is chosen because links l3 and l4 provide reduced bandwidth below average.

[0061] A selection means is provided for selecting at least one optimization target (206). Depending on the configuration of the communication network, there are multiple optimization goals that can be formulated to solve the constraint problem. An example of at least one optimization goal includes: - Minimize the worst-case end-to-end latency stream(i).delay. - Minimize the link-specific latency of each packet, stream(i).packet(j).delay([link(l)]). - Minimize the worst-case end-to-end jitter stream(i).Δdelay. - Maximize the utilization rate of 5G links, i.e., maximize the sum of the rates link(l).maxRate(t,b) for all 5G links to all resource blocks B. - Maximize the number of users supported.

[0062] Adjustment means are provided for adjusting constraints on the selected segment of the communication network (208).

[0063] The determination means 210 is provided to determine whether the selected constraints can be satisfied by the selected segment of the communication network.

[0064] If the selected constraints cannot be satisfied by the selected segments, the decision means determines a solution to the competition, for example, by adjusting at least one constraint and / or at least one optimization objective (218).

[0065] If the selected constraints can be satisfied by the selected segment, the decision means determines at least one preliminary instance of prescheduling for one of the selected segments of the communication network based on a plurality of cyclic data stream parameters, associated QoS requirements, and network capability information related to the first segment (212). In particular, decision 212 includes determining a solution that optimizes the selected target (e.g., an offset related to a link of a network entity).

[0066] For example, constraints define a set of feasible scheduling realizations. Constraints are defined for heterogeneous communication networks consisting of TSNs and TSN-over-5G subnetworks. For example, prescheduling can be determined via three types of input parameters, namely, the network model and configuration of a given communication network in the form of capability information for each, the parameters and configuration of the i-th stream in the communication network in the form of cyclic data stream parameters, where I = 1, 2, ..., S, S is the total number of cyclic data streams, and user requests per cyclic data stream in the form of associated QoS parameters.

[0067] The task of this device is to determine the prescheduling of packets planned at each hop of the communication network. For example, the prescheduling can be uniquely defined by each stream i=1...S, each packet j=1...Pi in that stream, and the transmit offset τi,j,l of each link l=1...Li through which the packet passes, as shown in Figure 5.

[0068] For link (l), l=1...L, one of the links, at least one piece of ability information includes at least one of the following: - Link type (5G, TSN, etc.): link(l).type, -Available bandwidth for each link: link(l).maxRate, and -Transmission delay per link: link(l).delay.

[0069] For one of the cyclic data streams stream(i), at least one cyclic data stream parameter includes at least one of the following: -Network configuration: Number of links: link(l) -Time of arrival of frame (e.g., as cycle time): stream(i).cycleTime, and - Payload per frame: stream(i).packetSize.

[0070] For one of the cyclic data streams (i), at least one QoS parameter associated with at least one cyclic data stream parameter includes at least one of the following: - Target end-to-end delay on the network: stream(i).delay, -Target end-to-end jitter: stream(i).Δdelay -Target packet error rate: stream(i).errorRate.

[0071] An update means is provided for updating the offset determined in at least step 212 (216).

[0072] Constraints are determined based on capability information. In yet another example, capability information represents constraint conditions. Constraints can be categorized into general network constraints and technology-specific constraints, such as TSN or 5G in this case.

[0073] The network constraints include at least one of the following: -Frame constraint: For each stream i=1...S, its frame j=1...P must have a positive transmission offset stream(i).frame(j) and be scheduled within its cycle time stream(i).cycleTime. - Transmission order: Each frame in the communication network is transmitted on the next link (l) only after it has been fully received in advance on the preceding link (link(l-1)). stream(i).packet(j).offset[link(l-1)] <stream(i).packet(j).offset[link(l)]、 - End-to-end latency: Each frame in a communication network must have a latency budget within that frame and be delivered to its respective endpoint. stream(i).packet(j).offset[link(Li)]‐stream(i).packet(j).offset[link(1)] <stream(i).delay。

[0074] Furthermore, more requirements-based constraints can be defined for each stream, such as jitter (stream(i).Δdelay) and packet loss (stream(i).errorRate). Constraints regarding delivery order may also apply, such as when frames must be transmitted in bursts.

[0075] The TSN constraint includes at least one of the following: - Single-link use: Each wired TSN link (link(l).type=TSN) is used exclusively by one frame at a time. Therefore, two packets on the network, stream(i).packet(j), must not interfere with each other on the same link; that is, exclusive access for each frame must be scheduled. - Clearly defined windows: In wired TSN segments, each frame is scheduled based on its traffic class, rather than individually. TSN supports up to eight traffic classes that group frames from different streams with identical or similar requirements. If pre-scheduled packets belong to a single traffic class, this constraint ensures that the gates for each traffic class in the Gate Control List (GCL) are opened at their respective egress ports. - Handling constraints when multiple traffic classes access the link simultaneously - Ingress filtering - Queueing behavior.

[0076] Wireless domain restrictions include at least one of the following: - Transmission Opportunities: Unlike Ethernet-based systems, where frames can be transmitted at any given time, wireless domain frames can only be transmitted at specific discrete points in time. These transmission opportunities are configurable but are typically fixed for each active stream and depend on the Transmit Time Interval (TTI):

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[0077] The following examples illustrate how to determine a preschedule based on the constraint of capability information. There are several options for deriving a preschedule based on capability information. Possible solver frameworks include, for example, (mixed)integer linear programming ((M)ILP), constraint programming (CP), or satisfiable module theory (SMT). Various approaches are possible for optimization: - No optimization: Based on the constraints, it is possible to derive a schedule that satisfies all the necessary requirements. Typically, there are either many solutions or no solutions at all. Therefore, constraints are used only to determine whether the satisfaction of the scheduling problem is achievable. - Single optimization: It is possible to set a single optimization goal, i.e., a specific value that should be minimized or maximized while satisfying constraints. For example, minimizing the sum of the worst end-to-end latencies of all streams is such an optimization goal.

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[0078] To determine each preliminary schedule, a determination means 204 is provided to determine whether all segments have been visited. If the answer is yes, the preliminary prescheduling is determined to be the final prescheduling. If further segments of the communication network are awaiting determination of their respective preliminary prescheduling, the procedure continues to step 204.

[0079] This method works well for appropriately selected network segments. In the case of TSN and TSN-over-5G implementations as illustrated in Figure 1, all network participants provide information about the network state and node capabilities to device 100 in Figure 1, making it easy to extract information for determining appropriate segmentation. Using these input parameters, the central device determines the appropriate segmentation of the network and deploys the configuration to the network in a pre-scheduled manner.

[0080] One possible approach is to first investigate the available and required bandwidth for all cyclic data streams on each network entity. The more users sharing the same link, the greater the impact of pre-scheduling on overall end-to-end performance. Therefore, one should first select the set of coherent nodes with the highest utilization within the network. Then, the optimization goal for this segment is determined, and constraints are adjusted. For example, a new latency constraint may be set for one of the segments, but of course, this constraint must be lower than the end-to-end latency requirement of the stream, stream(i).delay. This subnetwork can then be optimized to determine the transmission offset of the cyclic data streams passing through its links. The offsets for all remaining links in the communication network can then be iteratively resolved.

[0081] After subnetworks have been predetermined, scheduling may become unfeasible. That is, scheduling conflicts may occur where constraints are not met. In this case, there are two options: determine a different segmentation or readjust the subnetwork constraints. While this doesn't happen frequently, if it does, it indicates that the segmentation was not chosen appropriately or doesn't work well for commonly conceivable communication networks. This approach works better the more heterogeneous the network.

[0082] Figure 3 is a schematic flowchart. The selection means for selecting a first selection segment includes the steps of: determining a plurality of current usages related to wired and wireless links based on provided first and second capability information; and determining a first selection segment that includes a plurality of connected links among links whose related current usage exceeds a usage threshold.

[0083] Figure 4 shows a schematic flowchart. The selection of the first selection segment 204 comprises the steps of determining multiple bandwidths of wired and wireless links based on the provided first and second capability information, and determining the first selection segment which includes multiple connected links whose associated bandwidth is below a bandwidth threshold. After a resource-efficient solution (maintaining some upper limit on the latency of the selection segment) is found, the rest of the network can be optimized to have the lowest end-to-end latency for the pre-scheduled segments.

[0084] Figure 5 schematically illustrates how packets of each cyclic data stream are scheduled by offset on each link of a communication network. For example, summarizing the offsets along a selected path in the communication network makes it possible to determine whether the relevant QoS parameters can be met from a latency perspective. [Explanation of Symbols]

[0085] L1, L2, L3 wired links L4, L5 wireless links App#1, App#2, App#i Communication Endpoints ci1#1-3 First ability information ci2#4-5 Second ability information CN Communications Network cp#1, cp#2 Cyclic Data Stream Parameters l1-5 Links NE#1-6 Network Entity PS Pre-Schedule QoS #1, QoS #2 QoS Requirements SCHED#1 Scheduler Entity seg#1, seg#2 First selected segment

Claims

1. A method performed by a device (100) that determines a prescheduling (PS) for a communications network (CN), Step (102) of receiving a plurality of cyclic data stream parameters (cp#1, cp#2) and associated QoS requirements (QoS#1, QoS#2), wherein at least one of the plurality of cyclic data stream parameters (cp#1, cp#2) characterizes the arrival of at least frames of associated cyclic data streams of a communication network (CN) and associated communication endpoints (App#1, App#2, App#i), (104) A step of receiving first capability information (ci1#1-3) that characterizes the capabilities of each wired link (l1, l2, l3) of the communication network (CN), (106) A step of receiving second capability information (ci2#4-5) that characterizes the capabilities of each wireless link (l3, l5) of the aforementioned communication network (CN), (108) A step of determining a prescheduling (PS) that determines a transmission time offset (τ) on the link (l1-5) of the network entity (SCHED#1, NE#1-6) through which each packet of the cyclic data stream passes, based on the plurality of cyclic data stream parameters (cp#1, cp#2), the associated QoS requirements (QoS#1, QoS#2), the first capability information (ci1#1-3), and the second capability information (ci2#4-5), which is determined before the frames of the cyclic data stream reach the network entity (SCHED#1, NE#1-6), and which determines at least the transmission time offset (τ) on the link (l1-5) of the network entity (SCHED#1, NE#1-6) through which each packet of the cyclic data stream passes. (110) step of configuring at least one of the network entities (SCHED#1, NE#1-6) of the communication network (CN) based on at least one prescheduled (PS) determined, A method that includes this.

2. The step of determining the aforementioned prescheduling (PS) (108) is, (204) step of sequentially selecting at least one segment (seg#1-3) of the communication network (CN) based on the first capability information (ci1#1-3) and the second capability information (ci2#4-5), (212) A step of determining at least one spare instance of prescheduling (PS) for one selected segment of the segments (seg#1-3) of the communication network (CN) based on the plurality of cyclic data stream parameters (cp#1, cp#2), the associated QoS requirements (QoS#1-2), and capability information (ci) associated with the segments (seg#1-3), The method according to claim 1, including the method described in claim 1.

3. The method according to claim 2, in the step of sequentially selecting at least one segment (seg#1-3) of the communication network (CN) (204), wherein the first selected segment (seg#2, seg#1) that is selected first includes a wireless link or a wired link (l4-l5, l1-3), and the second selected segment (seg#1, seg#2) that is selected next includes a wired link or a wireless link (l1-3, l4-5).

4. The step of sequentially selecting at least one segment (seg#1-3) of the communication network (CN) (204) (302) A step of determining a plurality of current usages related to the wired and wireless links (l1-5) based on the provided first and second capability information (cp1, cp2), The steps include (304) determining a first selection segment (seg#1-3) which includes multiple connected links from among the links (l1-5) whose current usage exceeds the usage threshold, The method according to claim 2, including the method described in claim 2.

5. The step of sequentially selecting at least one segment (seg#1-3) of the communication network (CN) (204) (402) A step of determining a plurality of bandwidths for the wired and wireless links (l1-l5) based on the provided first and second capability information (cp1, cp2), The steps include (404) determining a first selection segment (seg#1-3) which includes multiple connected links among the links (l1-5) whose associated bandwidth is below the bandwidth threshold, The method according to claim 2, including the following:

6. The method according to any one of claims 1 to 5, wherein the prescheduling (PS) includes at least one gate control list associated with a network entity (NE#1-4) that provides service to at least one of the wired links (l1, l2, l3) of the communication network (CN).

7. The method according to any one of claims 1 to 5, wherein the prescheduling (PS) includes at least a predicted cyclic traffic volume per hour and per radio link (l4, l5) for a scheduler entity (SCHED#1) configured to schedule at least one network entity (NE#4-6) that provides services to at least one of the radio links (l4, l5) of the communication network (CN).

8. The method according to claim 6, wherein the prescheduling (PS) includes at least one gate control list for at least one wired link (l3) of the network translator entity (NE#4), and a predicted hourly, per-wireless-link (l4, l5) cyclic traffic volume for a scheduler entity (SCHED#1) configured to schedule the network translator entity (NE#4) to serve at least one of the wireless links (l4, l5) associated with the network translator entity (NE#4).

9. A device (100) for determining prescheduling (PS) for a communication network (CN), A receiving means (102) that receives a plurality of cyclic data stream parameters (cp#1, cp#2) and associated QoS requirements (QoS#1, QoS#2), wherein at least one of the plurality of cyclic data stream parameters (cp#1, cp#2) characterizes the arrival of at least frames of associated cyclic data streams of a communication network (CN) and associated communication endpoints (App#1, App#2, App#i), A receiving means (104) that receives first capability information (ci1#1-3) characterizing the capabilities of each wired link (l1, l2, l3) of the aforementioned communication network (CN), A receiving means (106) that receives second capability information (ci2#4-5) characterizing the capabilities of each wireless link (l3, l5) of the aforementioned communication network (CN), A determination means (108) determines a prescheduling (PS) which is determined before the frames of the cyclic data stream reach a network entity (SCHED#1, NE#1-6) and which determines at least a transmission time offset (τ) on the link (l1-5) of the network entity (SCHED#1, NE#1-6) through which each packet of the cyclic data stream passes, based on the plurality of cyclic data stream parameters (cp#1, cp#2), the associated QoS requirements (QoS#1, QoS#2), the first capability information (ci1#1-3), and the second capability information (ci2#4-5), An apparatus (100) comprising: configuration means (110) for configuring at least one network entity (SCHED#1, NE#1-6) of the communication network (CN) based on at least one determined preschedule (PS).

10. The determination means (108) that determines the prescheduling (PS) is A selection means (204) that sequentially selects at least one segment (seg#1-3) of the communication network (CN) based on the first capability information (ci1#1-3) and the second capability information (ci2#4-5), Apparatus (100) according to claim 9, comprising determination means for determining (212) at least one preliminary instance of prescheduling (PS) for one selected segment of the segments (seg#1-3) of the communication network (CN) based on the plurality of cyclic data stream parameters (cp#1, cp#2), the associated QoS requirements (QoS#1-2), and capability information (ci) associated with the segments (seg#1-3).

11. The apparatus (100) according to claim 10, wherein the first selection segment (seg#2, seg#1) initially selected by the selection means (204) includes a wireless link or a wired link (l4-l5, l1-3), and the second selection segment (seg#1, seg#2) subsequently selected includes a wired link or a wireless link (l1-3, l4-5).

12. The selection means (204) A determination means (302) that determines a plurality of current usage statuses related to the wired and wireless links (l1-5) based on the provided first and second capability information (cp1, cp2), A determination means (304) for determining a first selection segment (seg#1-3) which includes multiple connected links among the links (l1-5) whose current usage exceeds the usage threshold, The apparatus (100) according to claim 10, including the following:

13. The selection means (204) A determination means (402) that determines a plurality of bandwidths of the wired and wireless links (l1-l5) based on the provided first and second capability information (cp1, cp2), The apparatus (100) according to claim 10, further comprising (404) determination means for determining a first selection segment (seg#1-3) which includes a plurality of connected links among the links (l1-5) whose associated bandwidth is below a bandwidth threshold.

14. The apparatus (100) according to any one of claims 9 to 13, wherein the prescheduling (PS) includes at least one gate control list associated with a network entity (NE#1-4) that provides service to at least one of the wired links (l1, l2, l3) of the communication network (CN).

15. The apparatus (100) according to any one of claims 9 to 13, wherein the prescheduling (PS) includes at least a predicted cyclic traffic volume per hour and per radio link (l4, l5) for a scheduler entity (SCHED#1) configured to schedule at least one network entity (NE#4-6) that provides services to at least one of the radio links (l4, l5) of the communication network (CN).

16. The apparatus (100) according to claim 14, wherein the prescheduling (PS) includes a gate control list for at least one wired link (l3) of a network translator entity (NE#4) and a predicted cyclic traffic volume per hour and per radio link (l4, l5) for a scheduler entity (SCHED#1) configured to schedule the network translator entity (NE#4) to provide service to at least one of the radio links (l4, l5) associated with the network translator entity (NE#4).

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