Node remapping techniques for bus-based communication systems

Abstract

A bus-based communication includes: a master node; one or more secondary nodes, each secondary node being assigned an original node identifier; and a bus electrically connecting the primary node and the one or more secondary nodes to each other according to a bus-based communication protocol. The bus-based communication protocol defines a predefined number of sequentially numbered available node identifiers, and the original node identifier assigned to each secondary node corresponds to one of the sequentially numbered available node identifiers defined by the bus-based communication protocol of the bus. The primary node implements a remapping technique that renumbers the original node identifier assigned to the secondary node.

Description

Technical Field

[0001] The present invention relates to a bus-based communication system including a master node and a plurality of secondary nodes. The master node implements a node remapping technique that renumbers original node identifiers assigned to secondary nodes into sequentially numbered updated node identifiers to improve communication latency. Background Art

[0002] Ethernet is an efficient and universally applicable method of establishing communications between two or more physical devices (also referred to as nodes) that are part of a network. The Ethernet communication protocol defines the specific types of physical devices required for the network, such as, for example, the type of cables, the topology, and the maximum length of the cables. In one specific example of an Ethernet communication protocol, the 10Base-T network protocol specifies the number "10" to indicate a transmission speed of ten megabits per second, the word "base" stands for baseband, and the letter "T" represents a twisted pair cable.

[0003] Collision avoidance techniques are widely used in telecommunications and computer networks to avoid resource contention. Specifically, collision avoidance techniques attempt to eliminate situations where multiple nodes attempt to access the same resource. This ensures that any node in the network can send a signal without conflicting with other services on the network. The 10Base-T communication protocol uses physical layer collision avoidance (PLCA) to prevent conflicts when multiple nodes attempt to send data at the same time. In PLCA, transmission opportunities are assigned to each node in a round-robin manner, where only one node is allowed to send data at any time. Each node is assigned a node identifier, starting with the coordinating node assigned identifier 0 (PHYID=0) and ending with the last node in the network assigned identifier 255 (PHYID=255). The 10Base-T communication protocol includes a total of 256 available node identifiers. However, in many cases, the network does not utilize all available node identifiers. It should be understood that each sequential node identifier is given the opportunity to send data regardless of whether the physical device is assigned a dedicated node identifier. For example, if there is a number gap between a node assigned identifier 200 and another node assigned identifier 255, the network will still assign opportunity times to transmit data between node identifiers 200 and 255. Assigning a transmit opportunity to each node identifier, regardless of whether a device is assigned, introduces communication latency to the network.

[0004] Therefore, while current communication protocols achieve their intended purposes, there is a need in the art for an improved method of data transmission that reduces communication latency. Summary of the invention

[0005] According to several aspects, a bus-based communication system is disclosed. The bus-based communication system includes a master node; one or more secondary nodes, each of which is assigned an original node identifier; and a bus that electrically connects the master node and the one or more secondary nodes to each other according to a bus-based communication protocol. The bus-based communication protocol defines a predefined number of available sequentially numbered node identifiers, and the original node identifier assigned to each secondary node corresponds to one of the available sequentially numbered node identifiers defined by the bus-based communication protocol of the bus. The master node implements a remapping technique that renumbers the original node identifiers assigned to the secondary nodes by removing unused available sequentially numbered node identifiers. The master node renumbers the original node identifiers by renumbering the original node identifiers corresponding to the secondary nodes to updated sequentially numbered node identifiers and resetting the total number of available sequentially numbered node identifiers to be equal to the total number of secondary nodes that are part of the bus-based communication system.

[0006] In another aspect, a total number of transmission opportunities provided by the bus-based communication system during a periodic cycle is equal to a total number of secondary nodes that are part of the bus-based communication system.

[0007] In yet another aspect, a bus-based communication protocol employs one or more collision avoidance techniques that allocate transmit opportunities to each node that is part of the bus-based communication system to avoid collisions with traffic on the bus-based communication system.

[0008] In one aspect, the bus-based communication protocol is a 10Base-T network protocol.

[0009] In another aspect, the one or more collision avoidance techniques include physical layer collision avoidance (PLCA).

[0010] In yet another aspect, each sequentially numbered available node identifier represents an unused physical network interface that is part of the bus, wherein the unused physical network interface is not connected to an available node.

[0011] In one aspect, renumbering original node identifiers corresponding to secondary nodes includes sending a multicast request to all secondary nodes, wherein the multicast request requests the corresponding original node identifier from each secondary node that is part of the bus-based communication system, and waiting for a predefined wait time that provides each secondary node that is part of the bus-based communication system with an opportunity to respond to the multicast request.

[0012] In another aspect, renumbering original node identifiers corresponding to secondary nodes includes creating a lookup table that associates a physical address of each secondary node that is part of the bus-based communication system with a corresponding original identifier, wherein the lookup table lists the secondary nodes in order based on the original node identifier.

[0013] In yet another aspect, renumbering the original node identifiers corresponding to the secondary nodes includes renumbering the original node identifiers sequentially listed in a lookup table to sequentially numbered updated node identifiers.

[0014] In one aspect, the physical address is a Media Access Control (MAC) address.

[0015] In another aspect, the bus-based communication protocol is a Controller Area Network (CAN) bus protocol.

[0016] In yet another aspect, the primary node and the secondary node each include a unique microprocessor and a unique physical device.

[0017] In one aspect, the unique physical device is one of: a sensor and an actuator.

[0018] In another aspect, a method for implementing a remapping technique is disclosed that renumbers original node identifiers assigned to one or more secondary nodes that are part of a bus-based communication system. The method includes removing, by a master node, unused sequentially numbered available node identifiers, wherein a bus electrically connects the master node and the one or more secondary nodes to each other according to a bus-based communication protocol, and wherein the bus-based communication protocol defines a predefined number of sequentially numbered available node identifiers, and an original node identifier assigned to each secondary node corresponds to one of the sequentially numbered available node identifiers defined by the bus-based communication protocol of the bus. The method includes renumbering, by the master node, the original node identifier corresponding to the secondary node to an updated sequentially numbered node identifier. The method also includes resetting, by the master node, a total number of sequentially numbered available node identifiers that is equal to the total number of secondary nodes that are part of the bus-based communication system.

[0019] In another aspect, renumbering original node identifiers corresponding to secondary nodes includes sending a multicast request to all secondary nodes, wherein the multicast request requests the corresponding original node identifier from each secondary node that is part of the bus-based communication system, and waiting for a predefined wait time that provides each secondary node that is part of the bus-based communication system with an opportunity to respond to the multicast request.

[0020] In yet another aspect, renumbering original node identifiers corresponding to secondary nodes includes creating a lookup table that associates a physical address of each secondary node that is part of the bus-based communication system with a corresponding original identifier, wherein the lookup table lists the secondary nodes in order based on the original node identifier.

[0021] In one aspect, renumbering the original node identifiers corresponding to the secondary nodes includes renumbering the original node identifiers sequentially listed in a lookup table to sequentially numbered updated node identifiers.

[0022] In another aspect, a bus-based communication system is disclosed. The bus-based communication system includes: a master node; one or more secondary nodes, each secondary node being assigned an original node identifier; and a bus that electrically connects the master node and the one or more secondary nodes to each other according to a bus-based communication protocol, and wherein the bus-based communication protocol defines a predefined number of sequentially numbered available node identifiers, and the original node identifier assigned to each secondary node corresponds to one of the sequentially numbered available node identifiers defined by the bus-based communication protocol of the bus. The master node implements a remapping technique that renumbers the original node identifiers assigned to the secondary nodes by removing unused sequentially numbered available node identifiers, renumbering the original node identifiers corresponding to the secondary nodes to sequentially numbered updated node identifiers, and resetting the total number of sequentially numbered available node identifiers to equal the total number of secondary nodes that are part of the bus-based communication system. The total number of transmission opportunities provided by the bus-based communication system during a periodic cycle is equal to the total number of secondary nodes that are part of the bus-based communication system.

[0023] In another aspect, a bus-based communication protocol employs one or more collision avoidance techniques that allocate transmit opportunities to each node that is part of the bus-based communication system to avoid collisions with traffic on the bus-based communication system.

[0024] In yet another aspect, the bus-based communication protocol is a 10Base-T network protocol.

[0025] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0027] Figure 1is a schematic diagram of a disclosed bus-based communication system according to an exemplary embodiment, the bus-based communication system including a primary node and one or more secondary nodes in electronic communication with each other via a bus;

[0028] Figure 2 FIG. 1 shows a diagram of a primary node after implementing a remapping technique for renumbering original node identifiers assigned to secondary nodes according to an exemplary embodiment. Figure 1 The bus-based communication system shown; and

[0029] Figure 3 is a process flow diagram illustrating a method for renumbering original node identifiers assigned to secondary nodes according to an exemplary embodiment. DETAILED DESCRIPTION

[0030] The following description is merely exemplary in nature and is not intended to limit the present invention, application, or uses.

[0031] Reference Figure 1 , a schematic diagram of a bus-based communication system 10 as part of a vehicle 12 is shown. The bus-based communication system 10 includes a controller or master node 20, one or more secondary nodes 22, and a bus 24. The one or more secondary nodes 22 electronically communicate with each other and with the master node 20 via the bus 24. Figure 1 In the non-limiting embodiment shown, the bus-based communication system 10 is part of a vehicle 12, such as, but not limited to, a car, truck, sport utility vehicle, van, or car seat. However, it should be understood that Figure 1 It is merely exemplary in nature, and the bus-based communication system 10 is not limited to vehicles and may be used in a variety of applications.

[0032] The bus 24 electrically connects the primary node 20 and one or more secondary nodes 22 to each other according to a bus-based communication protocol that employs one or more conflict avoidance techniques that allocate transmit opportunities to each node that is part of the bus-based communication system 10 to avoid conflicts with traffic on the bus-based communication system 10. In one specific example, the bus-based communication protocol is a 10Base-T network protocol, and the conflict avoidance technique is a physical layer conflict avoidance (PLCA). However, it should be understood that other types of bus-based communication protocols may also be used, such as, for example, a controller area network (CAN) bus protocol.

[0033] The bus 24 includes a plurality of physical network interfaces 26, wherein each physical network interface 26 is connected to an available node (a primary node 20 or one of the plurality of secondary nodes 22). It should be understood that the bus-based communication protocol defines a predefined number of sequentially numbered available node identifiers 40, wherein each sequentially numbered available node identifier 40 corresponds to one of the physical network interfaces 26. A periodic transmission opportunity is provided for each sequentially numbered available node identifier 40, regardless of whether a physical device (e.g., one of the plurality of secondary nodes 22) is connected to the corresponding physical network interface 26. The transmission opportunity allows the node connected to the corresponding sequentially numbered available node identifier 40 to transmit status information. Figure 1 In the example shown, the bus-based communication protocol is the 10Base-T network protocol, and therefore the predefined number of sequentially numbered available node identifiers 40 is equal to 256 and is numbered [0, 1, 2, 3, 4, 5...254, 255], however, it should be understood that the predefined number of guaranteed transmission opportunities varies depending on the specific bus-based communication protocol.

[0034] The master node 20 and the secondary node 22 each include a unique microprocessor 30 and a unique physical device 32. The unique physical device 32 of the dedicated node 20, 22 is in electronic communication with and controlled by the unique microprocessor 30. Some examples of corresponding unique physical devices 32 include, but are not limited to, sensors and actuators. The master node 20 is assigned a unique node identifier or node ID, and the secondary nodes 22 are each assigned an original node identifier or original node ID. Both the unique node identifier and the original node identifier are represented as numbers. In Figure 1 In the example shown, the primary node 20 is assigned a unique node identifier of 0 (node ​​ID=0), while the secondary node 22 is assigned original node identifiers 1 and 254 (original node ID=1 and original node ID=254).

[0035] The original node identifier assigned to each secondary node 22 corresponds to the sequentially numbered available node identifiers 40 defined by the bus-based communication protocol of the bus 24. It should be understood that the original node identifier assigned to each secondary node 22 is not ordered sequentially, and the number of secondary nodes 22 included as part of the bus-based communication system 10 is less than the predefined number of sequentially numbered available node identifiers (e.g., there are 256 available sequentially numbered available node identifiers 40 and two secondary nodes 22). Figure 1In the example shown, one of the multiple secondary nodes 22 is assigned an original node identifier 1 (original node ID=1), which corresponds to the sequentially numbered available node identifier 1, and the remaining secondary nodes 22 are assigned an original node identifier 255 (original node ID=255), which corresponds to the sequentially numbered available node identifier 255.

[0036] As described above, the bus-based communication protocol of the bus 24 provides periodic transmission opportunities to each sequentially numbered available node identifier 40, regardless of whether the node is assigned to a corresponding physical network interface 26. However, because the number of secondary nodes 22 that are part of the bus-based communication system 10 is less than the total number of sequentially numbered available identifiers 40, providing transmission opportunities for each sequentially numbered available node identifier 40 introduces latency to the bus-based communication system 10. In order to reduce latency, the master node 20 implements a remapping technique that renumbers the original node identifiers assigned to the secondary nodes 22 into sequentially numbered updated node identifiers, each of which corresponds to one of the secondary nodes 22 that are part of the bus-based communication system 10.

[0037] Figure 2 The bus-based communication system 10 is shown after the primary node 20 has performed a remapping technique that renumbers the original node identifiers assigned to the secondary nodes 22 into updated sequentially numbered node identifiers. The original node identifiers are renumbered by removing unused sequentially numbered available node identifiers 40. As described above, each sequentially numbered available node identifier 40 represents a physical network interface 26 that is part of the bus 24, wherein the unused physical network interface 26 is not connected to an available node (either the primary node 20 or one of the plurality of secondary nodes 22). Figure 2 In the example shown, unused sequentially numbered available node identifiers 2-253 and 255 are removed.

[0038] The primary node 20 then renumbers the original node identifiers corresponding to the secondary nodes 22 into sequentially numbered updated node identifiers. The process of renumbering the original node identifiers is described below and is described in Figure 3 Reference Figure 1 and Figure 2, the secondary node 22 assigned the original node identifier 1 (original node ID=1) is renumbered as the updated node identifier 1 (updated node ID=1), and the remaining secondary nodes 22 assigned the original node identifier 255 (original node ID=254) are renumbered as the updated node identifier 2 (updated node ID=2). The master node 20 resets the total number of available node identifiers 40 in sequential order to be equal to the total number of secondary nodes 22 included as part of the bus-based communication system 10. Figure 2 In the example shown, the total number of secondary nodes 22 that are part of the bus-based communication system 10 is two.

[0039] It will be appreciated that the total number of transmission opportunities provided by the bus-based communication system 10 during a periodic cycle is equal to the total number of secondary nodes 22 that are part of the bus-based communication system 10. This means that Figure 2 The configuration shown provides two transmission opportunities to the secondary nodes 22 assigned updated node identifiers 1 and 2, which is consistent with Figure 1 The illustrated embodiment provides 255 transmission opportunities, thereby reducing communication latency. In one specific implementation based on the 10Base-T communication protocol, bus latency is improved by at least about 70%, and transmission latency from the secondary node 22 is improved by about 25%.

[0040] The renumbering of the original node identifiers corresponding to the secondary nodes 22 by the primary node 20 into sequentially numbered updated node identifiers will now be described. Figure 1 , the master node 20 first sends a multicast request to all secondary nodes 22, wherein the multicast request requests a corresponding original node identifier from each secondary node 22 that is part of the bus-based communication system 10. In response to receiving the multicast request, each secondary node 22 sends a corresponding original node identifier to the master node 20. After a predefined waiting time that provides each secondary node 22 that is part of the bus-based communication system 10 with an opportunity to respond to the multicast request, the master node 20 creates a lookup table that associates the physical address of each secondary node 22 with a corresponding original identifier (original node ID) of each secondary node 22 that is part of the bus-based communication system 10, wherein the lookup table lists the secondary nodes 22 in order based on the original node identifier.

[0041] Table A shown below corresponds to Figure 1Table A shows the physical address of each secondary node 22 as a media access control (MAC) address, where the secondary node 22 assigned with the original node identifier 1 (original node ID=1) includes the MAC address 02:xx:yy:zz:02 and the secondary node 22 assigned with the node identifier 254 (original node ID=254) includes the MAC address 03:xx:yy:zz:03.

[0042] Table A

[0043] Media Access Control (MAC) address Original Node ID 02:xx:yy:zz:02 1 03:xx:yy:zz:03 254

[0044] The master node 20 then renumbers the original node identifiers listed in sequence in the lookup table into updated node identifiers numbered in sequence. In the example shown in Table B, an additional column with a header "Updated Node ID" is introduced, where the Updated Node ID column lists the updated node identifiers numbered in sequence. Figure 1 and Figure 2 In the example shown, the secondary node assigned with the original node identifier 1 (original node ID = 1) is renumbered and assigned with the updated node identifier 1 (updated node ID = 1). The secondary node 22 assigned with the node identifier 254 (original node ID = 254) is renumbered and assigned with the updated node identifier 2 (updated node ID = 2).

[0045] Table B

[0046]

[0047]

[0048] Figure 3 is a process flow diagram illustrating a method 300 for renumbering an original node identifier corresponding to a secondary node 22 into a sequentially numbered updated node identifier. Figure 1 and Figure 3 , the method 300 may begin at block 302. In block 302, the primary node 20 sends a multicast request to all secondary nodes 22, wherein the multicast request requests a corresponding original node identifier from each secondary node 22 that is part of the bus-based communication system 10. The method 300 may then proceed to decision block 304.

[0049] In decision block 304, the master node 20 waits for a predefined wait time, and once the predefined wait time has elapsed, the method 300 may then proceed to block 306. The predefined wait time provides each secondary node that is part of the bus-based communication system with an opportunity to respond to the multicast request.

[0050] In block 306, the master node 20 creates a lookup table, such as Table A shown above, that associates the physical address of each secondary node 22 that is part of the bus-based communication system 10 with a corresponding original identifier, wherein the lookup table lists the secondary nodes 22 in order based on the original node identifier. The method 300 may then proceed to block 308.

[0051] In block 308, the original node identifiers listed sequentially in the lookup table are renumbered as sequentially numbered updated node identifiers. In the example shown in Table 3 above, the updated node identifiers are shown in the rightmost column as "Updated Node ID." Method 300 may then terminate.

[0052] Referring generally to the accompanying drawings, the disclosed bus-based communication system provides various technical effects and benefits. Specifically, the bus-based communication system significantly reduces bus time latency by remapping node identifiers associated with secondary nodes. The disclosed method also increases architectural flexibility by allowing nodes that are part of the bus-based communication system to be connected to or moved to different aggregators. Also as described above, in a specific implementation using the 10Base-T communication protocol, the disclosed method improves bus time latency by at least seventy percent and improves transmission latency from secondary nodes by about twenty-five percent.

[0053] The controller may refer to an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA), some or all of the above, or a portion of the above, such as in a system on a chip. In addition, the controller may be microprocessor-based, such as a computer having at least one processor, memory (RAM and / or ROM), and associated input and output buses. The processor may operate under the control of an operating system resident in the memory. The operating system may manage computer resources so that computer program code embodied as one or more computer software applications (such as applications resident in the memory) may have instructions executed by the processor. In an alternative embodiment, the processor may execute the application directly, in which case the operating system may be omitted.

[0054] The description of the present invention is merely exemplary in nature, and variations that do not depart from the gist of the present invention are intended to be within the scope of the present invention. Such variations should not be regarded as departing from the spirit and scope of the present invention.

Claims

1. A bus-based communication system, comprising: Master node; one or more secondary nodes, each of said secondary nodes being assigned an original node identifier; as well as a bus electrically connecting the primary node and the one or more secondary nodes to each other according to a bus-based communication protocol, wherein the bus-based communication protocol defines a predefined number of available sequentially numbered node identifiers, and the original node identifier assigned to each of the secondary nodes corresponds to one of the available sequentially numbered node identifiers defined by the bus-based communication protocol of the bus, wherein the primary node implements a remapping technique that renumbers the original node identifiers assigned to the secondary nodes by: Remove unused available sequentially numbered node identifiers; renumbering the original node identifier corresponding to the secondary node into a sequentially numbered updated node identifier; and The total number of sequentially numbered available node identifiers is reset to be equal to the total number of secondary nodes that are part of the bus-based communication system.

2. The bus-based communication system of claim 1, wherein: The total number of transmission opportunities provided by the bus-based communication system during a periodic cycle is equal to the total number of secondary nodes that are part of the bus-based communication system.

3. The bus-based communication system of claim 1, wherein: The bus-based communication protocol employs one or more collision avoidance techniques that allocate transmit opportunities to each of the nodes that are part of the bus-based communication system to avoid conflicts with traffic on the bus-based communication system.

4. The bus-based communication system of claim 3, wherein: The bus-based communication protocol is the 10Base-T network protocol.

5. The bus-based communication system of claim 3, wherein: The one or more collision avoidance techniques include physical layer collision avoidance (PLCA).

6. The bus-based communication system of claim 1, wherein: Each of the sequentially numbered available node identifiers represents an unused physical network interface that is part of the bus, wherein the unused physical network interface is not connected to an available node.

7. The bus-based communication system of claim 1, wherein: The renumbering the original node identifier corresponding to the secondary node comprises: sending a multicast request to all of the secondary nodes, wherein the multicast request requests the corresponding original node identifier from each secondary node that is part of the bus-based communication system; and A predefined wait time is waited, the predefined wait time providing each secondary node that is part of the bus-based communication system with an opportunity to respond to the multicast request.

8. The bus-based communication system of claim 7, wherein: The renumbering the original node identifier corresponding to the secondary node comprises: A lookup table is created that associates a physical address of each of the secondary nodes that are part of the bus-based communication system with a corresponding original identifier, wherein the lookup table lists the secondary nodes in order based on the original node identifier.

9. The bus-based communication system of claim 8, wherein: The renumbering the original node identifier corresponding to the secondary node comprises: The original node identifiers listed sequentially in the lookup table are renumbered as the sequentially numbered updated node identifiers.

10. The bus-based communication system of claim 8, wherein: The physical address is a Media Access Control (MAC) address.

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