Management device, communication system, vehicle, method, and program

Abstract

This invention relates to a management device, a communication system, a vehicle, a method, and a procedure. The management device manages multiple communication devices in a communication system that communicate according to a predetermined beacon cycle. The management device includes a processor. The processor obtains transmission data information (i.e., transmission data information) from each of the multiple communication devices, including the amount of data to be transmitted and transmission priority related to the data to be transmitted in the next beacon cycle. Based on the obtained transmission data information, the processor determines the amount of data allowed to be transmitted by each of the multiple communication devices in the next beacon cycle and notifies the multiple communication devices of the determined transmission data amount in the current beacon cycle.

Description

Technical Field

[0001] This disclosure relates to management devices, communication systems, vehicles, methods, and procedures in a communication system that communicates according to a prescribed beacon cycle. Background Technology

[0002] Japanese Patent Application Publication No. 2018-170550 discloses a system in which multiple nodes communicating via Time Division Multiple Access (TDMA) and a management node allocating time slots to the multiple nodes are connected via a network. The system describes how the management node determines whether a time slot reallocation is necessary based on the amount of data transmitted as notified separately from the multiple nodes, and then notifies the multiple nodes of the reallocated time slots.

[0003] When transmitting data, it is common to use storage areas (such as transmit buffers) that employ First-In-First-Out (FIFO) or Last-In-First-Out (FILO) methods. Furthermore, this storage area may contain data of varying priorities. In such situations, if time slots (frames) for each node are allocated solely based on data volume, the allocated time slots are consumed by low-priority data transmitted first according to the transmit buffer's storage order. This can sometimes lead to situations where the transmission of high-priority data cannot proceed or is delayed. Summary of the Invention

[0004] The purpose of this disclosure is to provide a management device, etc., that enables a communication system to prioritize the transmission of high-priority data.

[0005] One aspect of this disclosure relates to a management device configured to manage multiple communication devices in a communication system configured to communicate according to a predetermined beacon cycle. The management device includes a processor. The processor is configured to obtain transmission data information from each of the multiple communication devices, including the amount of data to be transmitted and transmission priority related to the data to be transmitted in the next beacon cycle; determine, based on the obtained transmission data information, the amount of data allowed to be transmitted to each of the multiple communication devices in the next beacon cycle; and notify the multiple communication devices of the determined amount of data to be transmitted in the current beacon cycle.

[0006] According to the management device of this disclosure, since the allocation of the amount of data that multiple communication devices can send in a beacon period is determined based on the transmission data information corresponding to the transmission priority information, the communication system as a whole can prioritize the transmission of high-priority data. Attached Figure Description

[0007] The features, advantages, technical and industrial significance of the exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein the same reference numerals denote the same elements, wherein,

[0008] Figure 1 This is a simplified configuration diagram of a communication system according to one embodiment of the present disclosure.

[0009] Figure 2A It is a functional module of the coordinator.

[0010] Figure 2B It is a follower module.

[0011] Figure 3 This is an example of a PLCA cycle.

[0012] Figure 4A This is a diagram illustrating the method for exporting data information.

[0013] Figure 4B This is a diagram illustrating the method for exporting data information.

[0014] Figure 5 It is a flowchart of the coordinator control process executed by the coordinator.

[0015] Figure 6 It is a flowchart of the follower control process executed by the follower.

[0016] Figure 7 This is the first specific example of the method by which the coordinator determines the amount of data that can be sent.

[0017] Figure 8 This is a diagram of the PLCA cycle for the allowed amount of data to be sent, based on the first specific example.

[0018] Figure 9 This is the second specific example of the method by which the coordinator determines the amount of data that can be sent.

[0019] Figure 10 This is a diagram of the PLCA cycle for the allowed amount of data to be sent, based on the second specific example.

[0020] Figure 11 This is the third specific example of the method by which the coordinator determines the amount of data that can be sent.

[0021] Figure 12 This is a diagram of the PLCA cycle based on the third specific example, which allows the amount of data to be sent. Detailed Implementation

[0022] In the basic form of scheduling multiple frame transmissions as a burst function, namely in a PLCA cycle with a constant beacon interval, the node (coordinator) of the management device submits transmission frame information (weighted calculation result of priority and number of frames) to the node (coordinator) of the management device in order to share the burst function frames of a certain node (follower) with other nodes (followers). The node (coordinator) of the management device performs rescheduling along the priority (modified PLCA cycle) by making adjustments, thereby giving high priority frames the opportunity to be transmitted even in a PLCA cycle with a constant period.

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0024] Implementation

[0025] [1] Composition

[0026] (1-1) Communication System

[0027] Figure 1 This is a block diagram illustrating a simplified configuration of a communication system 10 according to one embodiment of the present disclosure. Figure 1 The illustrated communication system 10 is configured such that multiple nodes 100-170, which are communication devices, are connected in multiple branches via a communication bus 180. This communication system 10 is, for example, mounted on a vehicle.

[0028] To prevent conflicts caused by multiple nodes 100-170 simultaneously starting to communicate, the communication system 10 is equipped with a Physical Level Collision Avoidance (PLCA) function. Hereinafter, a 10BASE-T1S network system will be used as an example to illustrate this embodiment, using the communication system 10 with PLCA installed.

[0029] Figure 1 Node 0-100 (hereinafter referred to as "coordinator 100") among the multiple nodes 100-170 shown is a node (management device) that has the function of controlling / managing the communication of the entire communication system 10. The coordinator 100 is assigned "#0" as an inherent ID for determining the order of transmission opportunities.

[0030] In addition, among the multiple nodes 100 to 170, Node 1-110 (hereinafter referred to as "First Follower 110"), Node 2-120 (hereinafter referred to as "Second Follower 120"), Node 3-130 (hereinafter referred to as "Third Follower 130"), Node 4-140 (hereinafter referred to as "Fourth Follower 140"), Node 5-150 (hereinafter referred to as "Fifth Follower 150"), Node 6-160 (hereinafter referred to as "Sixth Follower 160"), and Node 7-170 (hereinafter referred to as "Seventh Follower 170") are nodes (communication devices) controlled by Coordinator 100 for communication. Each of these nodes—First Follower 110, Second Follower 120, Third Follower 130, Fourth Follower 140, Fifth Follower 150, Sixth Follower 160, and Seventh Follower 170—is assigned a unique ID: "#1", "#2", "#3", "#4", "#5", "#6", and "#7".

[0031] (1-2) Coordinator

[0032] exist Figure 2A An example of the functional modules of the coordinator 100 is shown. Figure 2A The illustrated coordinator 100 includes a data acquisition unit 201, a decision unit 202, a setting change unit 203, and a notification unit 204. The functions of the data acquisition unit 201, the decision unit 202, the setting change unit 203, and the notification unit 204 are implemented by a processor included in the coordinator 100.

[0033] The acquisition unit 201 acquires and grasps transmission data information related to the data to be transmitted in the next beacon cycle (PLCA cycle) from the first follower 110 to the seventh follower 170. While details of this transmission data information will be described later, it includes the data volume (number of frames) and a weighted calculation result, i.e., the transmission priority. The decision unit 202 determines the amount of data allowed to be transmitted for the first follower 110 to the seventh follower 170 in the next beacon cycle (PLCA cycle) based on the multiple transmission data information acquired by the acquisition unit 201. If the coordinator 100 also has data to be transmitted, the transmission data information of this device is also included in the determination of the transmission data volume. While details of this determination method will be described later, it is performed by allocating the number of frames from the burst function launched from each of the first follower 110 to the seventh follower 170 to the transmission of high-priority frames (a variation of the PLCA cycle). The setting change unit 203 changes the PLCA setting according to the variation of the PLCA cycle determined by the decision unit 202. The notification unit 204 notifies each of the first follower 110 to the seventh follower 170 of the amount of data that the decision unit 202 has decided to allow.

[0034] (1-3) Followers

[0035] exist Figure 2B This is an example of a functional module shared by the first follower 110 to the seventh follower 170. Figure 2B The functional modules of each of the first follower 110 to the seventh follower 170 illustrated include a notification unit 211, an acquisition unit 212, and a setting change unit 213.

[0036] The notification unit 211 notifies the coordinator 100 of transmission data information related to the data that this device wants to transmit in the next beacon cycle (PLCA cycle). The acquisition unit 212 acquires from the coordinator 100 the amount of transmission data that this device is allowed to transmit in the next beacon cycle (PLCA cycle). The setting change unit 213 changes the PLCA settings based on the transmission data amount acquired by the acquisition unit 212.

[0037] [2] PLCA cycle

[0038] Figure 3 This illustrates the transmission cycle, also known as the PLCA cycle, used in communication system 10. For example... Figure 3 As shown, the PLCA cycle consists of one period (beacon cycle) from the beacon signal (B) used as the synchronization mode to the next beacon signal (B). Within one PLCA cycle, the coordinator 100, the first follower 110, the second follower 120, the third follower 130, the fourth follower 140, the fifth follower 150, the sixth follower 160, and the seventh follower 170 are sequentially given transmission opportunities. In each transmission opportunity, a predetermined number of frames, including data, are set after the TO signal indicating the start of the transmission opportunity and the commit signal (C).

[0039] In this embodiment, the first frame of each transmission opportunity is used for notification. Specifically, the first frame of the transmission opportunity of the coordinator 100 transmits the amount of data allowed for each of the first followers 110 to the seventh follower 170 as determined by the decision unit 202 (broadcast transmission). The first frame of the transmission opportunity of the first follower 110 transmits the transmission data information of the next beacon cycle (PLCA cycle) of the first follower 110 to the coordinator 100. The first frame of the transmission opportunity of the second follower 120 transmits the transmission data information of the next beacon cycle (PLCA cycle) of the second follower 120 to the coordinator 100. The first frame of the transmission opportunity of the third follower 130 transmits the transmission data information of the next beacon cycle (PLCA cycle) of the third follower 130 to the coordinator 100. The fourth follower 140 transmits its next beacon cycle (PLCA cycle) data to the coordinator 100 via the opening frame of its transmission opportunity. The fifth follower 150 transmits its next beacon cycle (PLCA cycle) data to the coordinator 100 via the opening frame of its transmission opportunity. The sixth follower 160 transmits its next beacon cycle (PLCA cycle) data to the coordinator 100 via the opening frame of its transmission opportunity. Furthermore, the seventh follower 170 transmits its next beacon cycle (PLCA cycle) data to the coordinator 100 via the opening frame of its transmission opportunity.

[0040] [3] Sending data information

[0041] exist Figure 4A as well as Figure 4B An example of transmission data sent by each of the first followers 110 to the seventh followers 170 to the coordinator 100 is shown. As a basic condition for creating the transmission data, data with a transmission priority of "high" (high priority frames) is assigned a weight of "10", data with a transmission priority of "medium" (medium priority frames) is assigned a weight of "4", and data with a transmission priority of "low" (low priority frames) is assigned a weight of "1". Furthermore, the transmission buffers (buffers that temporarily store data for transmission standby) of the coordinator 100 and each of the first followers 110 to the seventh followers 170 are first-in-first-out (FIFO) buffers.

[0042] Figure 4AThis is an example where high-priority, medium-priority, and low-priority frames are stored in the transmit buffer in their transmission order. In this example, the high-priority frame can be transmitted (output from the transmit buffer) before the medium-priority and low-priority frames. Therefore, each frame is assigned a weight corresponding to its transmission priority. Furthermore, as this... Figure 4A In the example of sending data information, the total weight value of the three frames is "15 (=10+4+1)" after adding the weights of the three frames, and the number of frames is three, with the logical value 1 indicating the storage location of the transmission buffer of the highest priority frame among the three frames, "100".

[0043] Figure 4B This is an example where three frames—low priority, medium priority, and high priority—are stored in the transmit buffer in the order they are sent. In this example, the high priority frame cannot be sent (output from the transmit buffer) before the medium and low priority frames. Therefore, to prioritize the transmission of the high priority frame, all frames up to the high priority frame are assigned the same weight "10" as the transmission priority "high," regardless of their respective transmission priorities. Furthermore, as this... Figure 4B In the example of sending data information, the total weight value of the three frames is "30 (=10+10+10)" after adding the weights of the three frames, and the number of frames is 3. The storage location of the transmission buffer of the high priority frame among the three frames is "001" with the logic value 1.

[0044] [4] Control

[0045] Next, further reference Figure 5 as well as Figure 6 The control of the coordinator 100 and each of the first followers 110 to the seventh followers 170 is described.

[0046] (4-1) Coordinator control

[0047] Figure 5 This is a flowchart illustrating the processing steps of coordinator control performed by coordinator 100. For example, if communication system 10 is powered on or enters a wake-up state, the coordinator control begins and is repeatedly executed until the beacon output stops due to the power being turned off or the communication system 10 entering a sleep state.

[0048] In step S501, the coordinator 100 outputs a beacon to signal the start of the PLCA cycle. If the coordinator 100 outputs a beacon, the process proceeds to step S502.

[0049] In step S502, the coordinator 100 determines whether an opportunity has arisen to transmit its own data to the communication bus 180 in frames. This opportunity can be determined by receiving a TO signal indicating the start of the transmission opportunity. If the transmission opportunity has arisen, the process proceeds to step S503.

[0050] In step S503, the coordinator 100 uses a leading frame to send to the communication bus 180 the allowed data transmission amounts for each of the first followers 110 to the seventh followers 170, as determined in the previous process (step S506 below). If the coordinator 100 sends the allowed data transmission amounts, the process proceeds to step S504.

[0051] In step S504, if there is data to be sent, the coordinator 100 uses frames following the initial frame to send the data to the communication bus 180. If the coordinator 100 has finished sending its own frames, the process proceeds to step S505.

[0052] In step S505, the coordinator 100 receives transmission data information for the next beacon cycle (PLCA cycle) from each of the first followers 110 to the seventh followers 170. This transmission data information can be obtained by receiving the start frame of the transmission opportunity of each of the first followers 110 to the seventh followers 170. If the coordinator 100 receives the next transmission data information from each of the first followers 110 to the seventh followers 170, the process proceeds to step S506.

[0053] In step S506, the coordinator 100 determines the number of frames (i.e., the amount of data allowed to be transmitted) allocated to each node (coordinator 100, each of the first followers 110 to the seventh followers 170) in the next beacon cycle (PLCA cycle) based on the next transmission data information received from each of the first followers 110 to the seventh followers 170 and the next transmission data information derived from the previous process (step S508 below). The method for determining this will be described later. If the coordinator 100 determines the amount of data allowed to be transmitted, the process proceeds to step S507.

[0054] In step S507, the coordinator 100 changes its own PLCA settings (PLCA cycle change) based on its determined allowable data transmission volume. If the coordinator 100 changes its own PLCA settings, the process proceeds to step S508.

[0055] In step S508, the coordinator 100 derives the desired transmission data for the next beacon cycle (PLCA cycle). If the coordinator 100 has derived its own transmission data for the next cycle, the process proceeds to step S501.

[0056] (4-2) Follower control

[0057] Figure 6 This is a flowchart illustrating the processing steps of follower control executed independently by each of the first follower 110 to the seventh follower 170. For example, if a beacon is output from the coordinator 100 due to the power-on or wakeup state of the communication system 10, the follower control begins and is repeated until the coordinator 100 stops outputting beacons.

[0058] In step S601, the nth follower 1n0 (n = 1 to 7) receives the beacon that marks the start of the PLCA cycle. If the nth follower 1n0 receives the beacon, the process proceeds to step S602.

[0059] In step S602, the nth follower 1n0 receives its allowed transmission data amount for this beacon period (PLCA period) from the coordinator 100. This transmission data information can be obtained by receiving the first frame in the transmission opportunity of the coordinator 100. If the nth follower 1n0 receives the allowed transmission data amount from the coordinator 100, the process proceeds to step S603.

[0060] In step S603, the nth follower 1n0 changes its own PLCA setting (PLCA cycle change) based on the amount of data it is allowed to send. If the nth follower 1n0 changes its own PLCA setting, the process proceeds to step S604.

[0061] In step S604, the nth follower 1n0 derives its desired transmission data for the next beacon cycle (PLCA cycle). If the nth follower 1n0 derives its own transmission data for the next cycle, the process proceeds to step S605.

[0062] In step S605, the nth follower 1n0 determines whether an opportunity has arrived to transmit its own data to the communication bus 180 in frames. This can be determined by receiving a TO signal indicating the start of its own transmission opportunity. If its transmission opportunity has arrived, the process proceeds to step S606.

[0063] In step S606, the nth follower 1n0 sends its next transmission data information, derived in step S604, to the coordinator 100. This transmission data information is sent using the beginning frame of the nth follower 1n0's transmission opportunity. If the nth follower 1n0 has sent the next transmission data information, the process proceeds to step S607.

[0064] In step S607, if the nth follower 1n0 has data to send, it uses frames after the first frame to send the data to the communication bus 180. If the nth follower 1n0 has finished sending its own frames, the process proceeds to step S601.

[0065] [5] Method for determining the amount of data allowed to be sent

[0066] Reference Figures 7 to 12 The method for determining the amount of data that can be sent by the decision unit 202 of the coordinator 100 will be specifically explained.

[0067] In each specific example, the initial value of the number of frames allocated a transmission opportunity to the 8 nodes in the PLCA cycle is "3", and the total number of frames that can be used for data transmission as a whole in the PLCA cycle is "16 (= 2 frames outside the front end × 8 nodes)". In addition, the weight assigned to data with "high" transmission priority (high priority frame) is "10", the weight assigned to data with "medium" transmission priority (medium priority frame) is "4", and the weight assigned to data with "low" transmission priority (low priority frame) is "1".

[0068] (5-1) First specific example

[0069] Figure 7 An example is shown where the total number of frames that the coordinator 100 and each of the first followers 110 to the seventh followers 170 want to send for data is less than the total number of frames mentioned above.

[0070] In this first specific example, the coordinator 100 is a buffer storage order that allows high-priority frames to be sent before low-priority frames. Therefore, the transmission data information of the coordinator 100 consists of a weighted sum of the weights of the two frames, "11 (=10+1)" and "10" indicating the transmission order of the high-priority frames, which are two in number (data volume).

[0071] Furthermore, the first follower 110 is a buffer storage order that cannot send high-priority frames, which are in the third order, compared to medium-priority frames and low-priority frames. Therefore, the transmission data information of the first follower 110 becomes a weighted sum of "30 (=10+10+10)" which sets the weights of the three frames to "high" and adds them together, and "001" which indicates the transmission order of the three frames (data volume) and the high-priority frames.

[0072] Furthermore, the second follower 120, the fifth follower 150, and the sixth follower 160 are buffer storage orders that cannot send medium-priority frames in the second order compared to low-priority frames. Therefore, the transmission data information of these second followers 120, fifth followers 150, and sixth followers 160 are respectively a weighted sum of "8 (=4+4)" which sets the weights of the two frames to "medium" and "00" which indicates that the number of frames (data volume) is two.

[0073] Furthermore, the third follower 130, the fourth follower 140, and the seventh follower 170 each store only one low-priority frame in their transmit buffers. Therefore, the transmit data information of these third follower 130, fourth follower 140, and seventh follower 170 is a weighted sum value of "1" and a value of "0" indicating that the number of frames (data volume) is one, respectively.

[0074] The first specific example, as described above, is the coordinator 100 and each of the first followers 110 to the seventh followers 170. The total number of frames desired for data transmission, "14 (=2+3+2+1+1+2+2+1)", is less than the total number of frames in the PLCA cycle, "16". Therefore, as by Figure 8 As shown in the PLCA cycle, the coordinator 100 and each of the first to seventh followers 110 are directly allocated the desired number of frames (data volume) (a variation of the PLCA cycle). For two frames that are less than the total number of frames "16", they can be allocated as follows: Figure 8 As shown in the shadow, it is installed on the seventh follower 170, or it can be allocated sequentially from the followers with smaller node numbers according to the use request of a new frame.

[0075] (5-2) Second specific example

[0076] Figure 9 An example is shown where the total number of frames desired for data transmission by the coordinator 100 and each of the first followers 110 to the seventh followers 170 exceeds the total number of frames described above. This second example, compared to the first example described above, Figure 9 The positions of the shaded areas in the transmitted data information of the second follower 120, the fifth follower 150, and the sixth follower 160 shown are different. Therefore, the following will explain these different transmitted data information.

[0077] In this second specific example, the second follower 120 is a buffer storage order that cannot send the high-priority frame, which is in the third order, compared to the medium-priority frame and the low-priority frame. In addition, the frame in the fourth order is a low-priority frame. Therefore, the transmission data information of the second follower 120 is a weight sum of "31 (=10+10+10+1)" which is the sum of the weights of the three frames up to the high-priority frame that are all set to "high" and the weight of the low-priority frame is kept as is, and "0010" which indicates that there are four frames (data volume) and the transmission order of the high-priority frames.

[0078] Furthermore, the fifth follower 150 is a buffer storage order that cannot send medium-priority frames (second and third priority) before the low-priority frames. Therefore, the transmission data information of the fifth follower 150 consists of a weighted sum of "12 (=4+4+4)" which sets the weight of the three frames to "medium" and indicates that the number of frames (data volume) is three.

[0079] Furthermore, the sixth follower 160 is a buffer storage order that cannot send the second-ranked medium-priority frame before the low-priority frame. Additionally, the third-ranked frame is a low-priority frame. Therefore, the transmission data information of the sixth follower 160 consists of a weighted sum of "9 (=4+4+1)" (the weights of the two frames up to the medium-priority frame are set to "medium" while the weight of the low-priority frame remains unchanged) and "000" indicating that the number of frames (data volume) is three.

[0080] In the second specific example, as described above, the total number of frames "18 (=2+3+4+1+1+3+3+1)" desired for data transmission by the coordinator 100 and each of the first followers 110 to the seventh follower 170 exceeds the total number of frames "16" of the PLCA cycle. In this case, the coefficient for allocating frames is calculated according to Equation 1 below, based on the total weighted sum of the coordinator 100 and each of the first followers 110 to the seventh follower 170 and the total number of frames. The coefficient for the second specific example calculated according to Equation 1 is 1 / 6 (=16 / 96 (=11+30+31+1+1+12+9+1)).

[0081] Coefficient = Total number of frames / Σ total weight value... [Equation 1]

[0082] Next, based on this coefficient, the provisional number of frames allocated to the coordinator 100 and each of the first followers 110 to the seventh followers 170 are calculated according to Equation 2 below. Here, ROUND is a function that rounds the first decimal place.

[0083] Provisional frame count = ROUND (coefficient × weight) ... [Equation 2]

[0084] According to Equation 2, the provisional number of frames allocated to the coordinator 100 and each of the first followers 110 to the seventh followers 170 is calculated as follows.

[0085] Coordinator 100:2 (=ROUND(1 / 6×11))

[0086] First Follower 110:5 (=ROUND(1 / 6×30))

[0087] Second follower 120:5 (=ROUND(1 / 6×31))

[0088] Third follower 130:0 (=ROUND(1 / 6×1))

[0089] Fourth follower 140:0 (=ROUND(1 / 6×1))

[0090] Fifth Follower 150:2 (=ROUND(1 / 6×12))

[0091] The sixth follower 160:2 (=ROUND(1 / 6×9))

[0092] Seventh Follower 170:0 (=ROUND(1 / 6×1))

[0093] Next, the provisional frame counts are reduced to the maximum number of frames desired by the coordinator 100 and each of the first to seventh followers 170 for data transmission. Specifically, although a provisional frame count of "5" is allocated to the first follower 110, three frames (data) are stored in the transmit buffer. Therefore, the provisional frame count of the first follower 110 is reduced to "3". Similarly, although a provisional frame count of "5" is allocated to the second follower 120, four frames (data) are stored in the transmit buffer. Therefore, the provisional frame count of the second follower 120 is reduced to "4".

[0094] The provisional number of frames after the reduction to the maximum frame value is as follows.

[0095] Coordinator 100:2

[0096] First Follower 110:3 (←5)

[0097] Second follower 120:4 (←5)

[0098] Third Follower 130:0

[0099] Fourth Follower 140:0

[0100] Fifth Follower 150:2

[0101] Sixth Follower 160:2

[0102] Seventh Follower 170:0

[0103] Furthermore, after processing to reduce the frame count to the maximum value, the total number of provisional frames is 13 (=2+3+4+0+0+2+2+0). Therefore, three frames that are insufficient to meet the total PLCA period requirement of "16" are ultimately allocated. This final allocation is performed sequentially from the node with the largest provisional frame count among the nodes that do not meet the requirement of a desired frame for data transmission. In the second specific example, since the coordinator 100, the first follower 110, and the second follower 120 meet the desired frame requirement, one frame is allocated to the fifth follower 150 and the sixth follower 160, which each have a large provisional frame count. Moreover, the remaining frame is allocated to the third follower 130, which has the smallest node number among the third follower 130, the fourth follower 140, and the seventh follower 170.

[0104] The number of frames after the final allocation process is as follows.

[0105] Coordinator 100:2

[0106] First Follower 110:3

[0107] Second follower 120:4

[0108] Third follower 130:1 (←0)

[0109] Fourth Follower 140:0

[0110] Fifth Follower 150:3 (←2)

[0111] Sixth Follower 160:3 (←2)

[0112] Seventh Follower 170:0

[0113] Through the above processing, all 16 frames of the PLCA cycle, which are accompanied by the deformation of the PLCA cycle, have been allocated. Therefore, as from... Figure 10 As shown in the PLCA cycle, coordinator 100, first follower 110, and second follower 120 are able to send high-priority frames stored in the transmit buffer in the next PLCA cycle. In contrast, fourth follower 140 and seventh follower 170 send low-priority frames stored in the transmit buffer in the next PLCA cycle after that.

[0114] (5-3) Third specific example

[0115] Figure 11This example illustrates a situation where the total number of frames desired for data transmission by the coordinator 100 and each of the first followers 110 to the seventh followers 170 exceeds the aforementioned total number of frames, and where there are high-priority frames among the coordinator 100 and each of the first followers 110 to the seventh followers 170. This third example, compared to the second example described above, Figure 11 The shaded areas in the transmitted data information of the third follower 130 to the seventh follower 170 shown are further different. Therefore, this further difference in transmitted data information will be explained below.

[0116] In this third specific example, the third follower 130 is the buffer storage order of the high-priority frame that cannot be sent first compared to the low-priority frame. Therefore, the transmission data information of the third follower 130 becomes a weight total value of "20 (=10+10)" which sets the weights of the two frames to "high" and adds them together, and "01" which indicates the transmission order of the high-priority frame with two frames (data volume).

[0117] Furthermore, the fourth follower 140 and the seventh follower 170 store only one high-priority frame in their transmit buffers. Therefore, the transmit data information of the fourth follower 140 and the seventh follower 170 are respectively a weighted total value of "10" and a value of "1" indicating that there is only one high-priority frame.

[0118] Furthermore, the fifth follower 150 is a buffer storage order that cannot send high-priority frames in the second order compared to low-priority frames. Additionally, the third-order frame is a medium-priority frame. Therefore, the transmission data information of this fifth follower 150 consists of a total weight value of "24 (=10+10+4)" which is the sum of the weights of the two frames up to the high-priority frame that are all set to "high" and the weight of the medium-priority frame is kept constant, and a value of "010" indicating the transmission order of the three frames (data volume) and the high-priority frames.

[0119] Furthermore, the sixth follower 160 is a buffer storage order that allows the high-priority frame, which is in the first order, to be sent before the medium-priority frame and the low-priority frame. Therefore, the data information transmitted by the sixth follower 160 is a weighted sum of the weights of the three frames, which is "15 (=10+4+1)" and "100" indicating the transmission order of the three high-priority frames.

[0120] The third specific example is as described above, where the total number of frames "19 (=2+3+4+2+1+3+3+1)" desired by the coordinator 100 and each of the first followers 110 to the seventh followers 170 for data transmission exceeds the total number of frames "16" of the PLCA cycle. In this case, based on the total weighted sum of the coordinator 100 and each of the first followers 110 to the seventh followers 170 and the total number of frames, the coefficient "16 / 151 (=11+30+31+20+10+24+15+10)" used for frame allocation is calculated according to Equation 1 above.

[0121] Furthermore, based on this coefficient, the provisional number of frames allocated to the coordinator 100 and each of the first followers 110 to the seventh followers 170 are calculated according to Equation 2 above.

[0122] Coordinator 100:1 (=ROUND(16 / 151×11))

[0123] First Follower 110:3 (=ROUND(16 / 151×30))

[0124] Second follower 120:3 (=ROUND(16 / 151×31))

[0125] Third follower 130:2 (=ROUND(16 / 151×20))

[0126] Fourth Follower 140:1 (=ROUND(16 / 151×10))

[0127] Fifth Follower 150:3 (=ROUND(16 / 151×24))

[0128] Sixth follower 160:2 (=ROUND(16 / 151×15))

[0129] The seventh follower 170:1 (=ROUND(16 / 151×10))

[0130] The total number of provisional frames after being reduced to the maximum value of the frame is 16 (=1+3+3+2+1+3+2+1), which is consistent with the total number of frames in the PLCA cycle. Therefore, these provisional frame numbers become the final number of allocated frames. In this third specific example, as by Figure 12 As shown in the PLCA cycle, the high-priority frames of coordinator 100 and each of the first followers 110 to the seventh follower 170 stored in the transmit buffer can be transmitted in the next PLCA cycle. In contrast, in the PLCA cycle after the next one, the low-priority frames of coordinator 100, the second follower 120, and the sixth follower 160 stored at the very end of the transmit buffer are transmitted.

[0131] Nodes that delay the transmission of low-priority frames to the next PLCA cycle or later can request (add) the desired number of frames (data size) in the subsequent data transmission information notified to the coordinator 100.

[0132] Function / Effect

[0133] As described above, in one embodiment of this disclosure, the coordinator (management device) 100 obtains transmission data information from the first follower 110 to the seventh follower 170 (a plurality of communication devices), which includes the amount of data and transmission priority related to the data to be transmitted in the next beacon cycle (PLCA cycle). Based on the obtained transmission data information, the coordinator determines the amount of data to be transmitted by the first follower 110 to the seventh follower 170 in the next beacon cycle, and notifies the first follower 110 to the seventh follower 170 of the determined amount of data to be transmitted in the current beacon cycle.

[0134] By using this process, since the allocation of the amount of data (frames) that the coordinator 100 and each of the first followers 110 to the seventh followers 170 can send within a beacon cycle (PLCA cycle) is determined based on the data information corresponding to the sending priority, the overall communication system 10 is more likely to send high-priority data (high-priority frames).

[0135] The above describes one embodiment of the present disclosure. However, the present disclosure can be understood not only as the management device described above, but also as a communication system including the management device and multiple communication devices, a vehicle equipped with the communication system, a method executed by the management device, a program of the method, or a non-transitory recording medium that can be read by a computer and stores the program.

[0136] The management device disclosed herein can be used in vehicles equipped with a 10BASE-T1S network system.

Claims

1. A management device configured to manage a plurality of communication devices in a communication system configured to communicate according to a predetermined beacon period, characterized in that the management device includes a processor configured to: The transmission data information, which includes information about the amount of data to be transmitted and the transmission priority related to the data to be transmitted in the next beacon cycle, is obtained from the aforementioned multiple communication devices. Based on the acquired multiple transmitted data information, the amount of data allowed to be transmitted by the multiple communication devices in the next beacon cycle is determined respectively; and During this beacon cycle, the aforementioned number of communication devices are notified of the determined amount of data to be transmitted.

2. The management device according to claim 1, characterized in that, The aforementioned communication system uses 10BASE-T1S in accordance with the IEEE 802.3cg standard.

3. The management device according to claim 1, characterized in that, The aforementioned transmission priority is the sum of the weights assigned to the data that should be transmitted, and the weights are calculated based on the storage location of the high-priority data among the data that should be transmitted stored in the transmission buffer of each of the aforementioned communication devices.

4. The management device according to claim 3, characterized in that, The processor is configured to determine the amount of data to be transmitted based on the total amount of data that can be transmitted in one beacon cycle, the sum of the amounts of data in the plurality of communication devices, and the sum of the weighted sums in the plurality of communication devices.

5. The management device according to claim 1, characterized in that, The processor is configured to notify the plurality of communication devices of the amount of data to be transmitted by sending the amount of data immediately following the beacon.

6. The management device according to any one of claims 1 to 5, characterized in that, The above data refers to frames, and the above data volume refers to the number of frames.

7. The management device according to claim 1, characterized in that, The aforementioned management device and the aforementioned multiple communication devices are vehicle-mounted devices installed in the vehicle.

8. A vehicle, characterized in that, It includes the management device as described in claim 1.

9. A communication system comprising a plurality of communication devices configured to communicate according to a predetermined beacon period and a management device configured to manage the plurality of communication devices, characterized in that, The aforementioned management device includes a processor, which is configured as follows: The transmission data information, which includes information about the amount of data to be transmitted and the transmission priority related to the data to be transmitted in the next beacon cycle, is obtained from the aforementioned multiple communication devices. Based on the acquired multiple transmitted data information, the amount of data allowed to be transmitted by the multiple communication devices in the next beacon cycle is determined respectively; and During this beacon cycle, the aforementioned number of communication devices are notified of the determined amount of data to be transmitted.

10. A method, performed by a management device configured to manage a plurality of communication devices in a communication system configured to communicate according to a predetermined beacon period, characterized in that the method comprises: The transmission data information, which includes information about the amount of data to be transmitted and the transmission priority related to the data to be transmitted in the next beacon cycle, is obtained from the aforementioned multiple communication devices. Based on the acquired multiple transmitted data information, the amount of data allowed to be transmitted by the multiple communication devices in the next beacon cycle is determined respectively; and During this beacon cycle, the aforementioned number of communication devices are notified of the determined amount of data to be transmitted.

11. A program that causes a processor included in a management device configured to manage a plurality of communication devices in a communication system to perform the following functions, wherein the communication system is configured to communicate according to a predetermined beacon period, characterized in that the functions include: The transmission data information, which includes information about the amount of data to be transmitted and the transmission priority related to the data to be transmitted in the next beacon cycle, is obtained from the aforementioned multiple communication devices. Based on the acquired multiple transmitted data information, the amount of data allowed to be transmitted by the multiple communication devices in the next beacon cycle is determined respectively; and During this beacon cycle, the aforementioned number of communication devices are notified of the determined amount of data to be transmitted.

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