Patent Description:
In the existing technology, 10BASE-T1S is expected to replace the existing multipoint network, such as the controller area network (CAN) bus. The CAN bus may preset identification information through the carrier sense multiple access with collision detection (CSMA/CD) protocol, and arbitrate priority during transmission, thereby reducing the transmission delay of data packets to achieve the goal of predictable transmission time.

Based on the IEEE <NUM>. 3cg-<NUM> standard, PLCA nodes share bandwidth evenly. Although the user may arrange the bandwidth by adjusting the maximum burst count so that some nodes have higher priority, these PLCA nodes with higher priority still need to wait for their own transmission opportunity (TO) to send data packets. This means that it may take a long time (for other nodes to complete the packet transmission) before the data packet is sent out.

<CIT> relates to an operating method of an end node in a vehicle network supporting a physical layer collision avoidance (PLCA) function.

Referring to <FIG> is a schematic diagram of a PLCA network according to an embodiment of the disclosure. In <FIG>, a PLCA network <NUM> includes PLCA devices <NUM> to 1N, in which the PLCA devices <NUM> to 1N may have the same or similar structure. Taking the PLCA device <NUM> as an example, it includes a communication circuit <NUM> and a controller <NUM>.

In one embodiment, the communication circuit <NUM> may be used, for example, to implement communication between the PLCA device <NUM> and other PLCA devices in the PLCA network <NUM>, and the communication circuit <NUM> may be implemented as a communication module with corresponding communication functions according to the communication protocol used for packet exchange between the PLCA devices <NUM> to 1N.

In one embodiment, the PLCA devices <NUM> to 1N may, for example, use the CSMA/CD protocol for packet exchange. In this case, the communication circuit <NUM> may, for example, be implemented as a communication module with CSMA/CD function, but not limited thereto.

The controller <NUM> is coupled to the communication circuit <NUM> and may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor, multiple microprocessors, one or more combined digital signal processing microprocessor, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit, state machine, advanced RISC machine (ARM) based processor and the like.

In <FIG>, the structure of the PLCA devices <NUM> to 1N may refer to the relevant description of the PLCA device <NUM>, and will not be repeated herein.

In the embodiment of the disclosure, the PLCA devices <NUM> to 1N respectively perform corresponding packet transmission in the PLCA network <NUM> according to the corresponding transmission opportunity.

Referring to <FIG> is a schematic diagram of a PLCA mechanism according to an embodiment of the disclosure. In the scenario shown in <FIG>, before the PLCA devices <NUM> to 1N actually operate the PLCA mechanism, the corresponding node identities of the PLCA devices <NUM> to 1N may be manually set, or the node identities of each of the PLCA devices <NUM> to 1N in the PLCA network <NUM> is determined based on a specific mechanism.

In the embodiment of the disclosure, it is assumed that the node identities of each of the PLCA devices <NUM> to 1N are expressed by a corresponding node number, and the node numbers of each of the PLCA devices <NUM> to 1N may correspond to the transmission priorities of each of the PLCA devices <NUM> to 1N in the PLCA network <NUM>.

In one embodiment, a PLCA device with a lower node number may, for example, have a higher transmission priority, but not limited thereto. For ease of description, it is assumed below that the node numbers of the PLCA devices <NUM> to 1N are respectively node numbers <NUM> to N, but this is only for example and not intended to limit the possible implementation of the disclosure.

In <FIG>, since the node numbers of the PLCA devices <NUM> to 1N are respectively assumed to be node numbers <NUM> to N, this means that the transmission priorities of the PLCA devices <NUM> to 1N are sequentially decreased. In this case, the transmission opportunities <NUM> to 21N of the PLCA devices <NUM> to 1N are arranged sequentially when the PLCA mechanism is operating.

In this case, when the PLCA mechanism is operating, the PLCA devices <NUM> to 1N are sequentially transmitted at the corresponding transmission opportunities, and after the transmission opportunity 21N corresponding to the PLCA device 1N ends (e.g. the PLCA device with the lowest transmission priority), it will be the turn for the transmission opportunity <NUM> corresponding to the PLCA device <NUM> again (e.g., the PLCA device with the highest transmission priority). Moreover, each of the PLCA devices <NUM> to 1N may determine which PLCA device the current transmission opportunity is corresponding to.

In one embodiment, when one of the PLCA devices <NUM> to 1N enters the emergency transmission mode, if this PLCA device is not the PLCA device corresponding to the current transmission opportunity, this PLCA device may need to wait a long time to transmit in the corresponding transmission opportunity.

For example, assuming that the PLCA device <NUM> enters the emergency transmission mode when the PLCA device <NUM> executes the corresponding transmission opportunity <NUM>, the PLCA device <NUM> needs to wait for the PLCA devices <NUM> to 1N, and <NUM> to complete the corresponding transmission opportunities <NUM> to 21N, and <NUM> in sequence, then the packet corresponding to the emergency transmission mode may be sent when executing the transmission opportunity <NUM> corresponding to the PLCA device <NUM>. Moreover, even if it is the turn of the PLCA device <NUM> entering the emergency transmission mode to execute the corresponding transmission opportunity <NUM>, the transmission time executed by the PLCA device <NUM> is also limited by the preset maximum transmission time (e.g., the above-mentioned maximum burst count), therefore, it may not be possible to completely send the packet corresponding to the emergency transmission mode.

In view of this, the disclosure provides a method for emergency transmission in the PLCA network, which may be used to solve the above technical problems. This is further described below.

Referring to <FIG> is a flowchart of a method for performing an emergency transmission in a PLCA network according to an embodiment of the disclosure. In an embodiment of the disclosure, the method in <FIG> may be executed by any one of the PLCA devices <NUM> to 1N in <FIG>. For the ease of description, it is assumed below that the steps in <FIG> are executed by the PLCA device <NUM>, and the details of the steps in <FIG> are described below in combination with the contents of <FIG>.

First, in step S310, in response to determining that the PLCA device <NUM> enters the emergency transmission mode, the controller <NUM> finds the first PLCA device from the PLCA network <NUM> that is performing the corresponding first packet transmission.

As mentioned above, each of the PLCA devices <NUM> to 1N may determine which PLCA device the current transmission opportunity is corresponding to. Based on this, in one embodiment, the controller <NUM> may determine the current transmission opportunity, and accordingly determine the first PLCA device that is currently performing the corresponding first packet transmission.

Taking <FIG> as an example, assuming that the controller <NUM> determines that the current transmission opportunity is the transmission opportunity <NUM>, the controller <NUM> may determine that the PLCA device <NUM> is the first PLCA device currently performing the corresponding first packet transmission. For another example, assuming that the controller <NUM> determines that the current transmission opportunity is the transmission opportunity 21N, the controller <NUM> may determine that the PLCA device 1N is the first PLCA device currently performing the corresponding first packet transmission, but not limited thereto.

In addition, in the scenario of <FIG>, if the controller <NUM> determines that the current transmission opportunity is the transmission opportunity <NUM> belonging to the PLCA device <NUM>, the controller <NUM> may determine that it is the turn of the PLCA device <NUM> to perform packet transmission, but not limited thereto.

Next, in step S320, in response to determining that the first transmission priority of the first PLCA device is lower than the transmission priority of the PLCA device <NUM>, the controller <NUM> suspends the first packet transmission of the first PLCA device.

As mentioned above, the transmission priorities of each of the PLCA devices <NUM> to 1N may be expressed as the node numbers of each of the PLCA devices <NUM> to 1N, and a lower node number corresponds to a higher transmission priority. Based on this, the controller <NUM> may, for example, determine whether the first transmission priority of the first PLCA device is lower than the transmission priority of the PLCA device <NUM> by determining whether the node number of the first PLCA device is higher than the node number of the PLCA device <NUM>.

In the first embodiment, in response to determining that the node number of the first PLCA device is lower than the node number of the PLCA device, the controller <NUM> may determine that the first transmission priority of the first PLCA device is higher than the transmission priority of the PLCA device <NUM>. In this case, the controller <NUM> may, for example, wait for the first PLCA device to complete the first packet transmission, but not limited thereto.

In the second embodiment, in response to determining that the node number of the first PLCA device is higher than the node number of the PLCA device <NUM>, the controller <NUM> may determine that the first transmission priority of the first PLCA device is lower than the transmission priority of the PLCA device <NUM>. In this case, the controller <NUM> may suspend the first packet transmission of the first PLCA device. In one embodiment, the controller <NUM> may, for example, control the communication circuit <NUM> to send an interference packet in the PLCA network <NUM> to suspend the first packet transmission of the first PLCA device. In this case, the transmission opportunity corresponding to the first PLCA device may be ended early so that the next transmission opportunity may start early. In this way, the effect of shortening the waiting time of the PLCA device <NUM> may be achieved, so that the PLCA device <NUM> may execute the corresponding transmission opportunity earlier.

In addition, after suspending the first packet transmission of the first PLCA device, the controller <NUM> may then find one or more second PLCA devices from the PLCA network <NUM> that perform the corresponding second packet transmission after the first PLCA device, and determine whether the second transmission priorities of each of the second PLCA devices are lower than the transmission priority of the PLCA device <NUM>.

In one embodiment, in response to determining that the second transmission priorities of each of the second PLCA devices are lower than the transmission priority of the PLCA device <NUM>, the controller <NUM> may suspend the second packet transmissions corresponding to each of the second PLCA devices.

For example, the controller <NUM> may send a corresponding interference packet in the PLCA network <NUM> through controlling the communication circuit <NUM> to suspend the second packet transmissions corresponding to each of the second PLCA devices when each of the second PLCA devices are performing the corresponding second packet transmissions.

Taking <FIG> as an example, it is assumed that the controller <NUM> determines that the current transmission opportunity is the transmission opportunity <NUM> corresponding to the PLCA device <NUM>. In this case, after the controller <NUM> determines that the transmission priority of the PLCA device <NUM> is lower than the transmission priority of the PLCA device <NUM>, the controller <NUM> may control the communication circuit <NUM> to send an interference packet in the PLCA network <NUM> to suspend the packet transmission of the PLCA device <NUM>. In this way, the transmission opportunity <NUM> may be ended earlier and the transmission opportunity <NUM> may be started earlier, thereby it is the turn of the transmission opportunity <NUM> sooner, so that the PLCA device <NUM> may send the emergency packet corresponding to the emergency transmission mode.

Next, after the controller <NUM> determines that the transmission priority of the PLCA device <NUM> (i.e., the PLCA device that performs the corresponding packet transmission after the PLCA device <NUM>) is lower than the transmission priority of the PLCA device <NUM>, the controller <NUM> may control the communication circuit <NUM> to send an interference packet in the PLCA network <NUM> to suspend the packet transmission of the PLCA device <NUM>. In this way, the transmission opportunity <NUM> may be ended earlier and the transmission opportunity <NUM> may be started earlier.

Based on the above principles, the controller <NUM> may suspend the packet transmissions of each of the PLCA devices <NUM> to 1N with the corresponding interference packet when the PLCA devices <NUM> to 1N execute the corresponding transmission opportunities <NUM> to 21N. In this way, the waiting time of the PLCA device <NUM> may be shortened, and the transmission opportunity <NUM> of the PLCA device <NUM> may be started earlier.

In step S330, in response to determining that it is the turn of the PLCA device <NUM> to perform the corresponding packet transmission (i.e., it is the turn of the transmission opportunity corresponding to the PLCA device <NUM>), the controller <NUM> controls the communication circuit <NUM> to send the emergency packet corresponding to the emergency transmission mode.

In one embodiment, the PLCA device <NUM> may continuously transmit the emergency packets until all the emergency packets are transmitted. In other words, the sum of the transmission time used by the PLCA device <NUM> for transmitting the emergency packets may be greater than the preset maximum transmission time of the PLCA device <NUM>, but not limited thereto.

In one embodiment, in response to determining that the packet transmission corresponding to the emergency packet has been completed, the controller <NUM> may control the PLCA device <NUM> to exit the emergency transmission mode. In this case, the PLCA device <NUM> may stop suspending the packet transmission of other PLCA devices with interference packets, and let the PLCA devices <NUM> to 1N operate based on the conventional PLCA mechanism, but not limited thereto.

In order to make the concept of the disclosure easier to understand, <FIG> is taken as an example for further description below. In the third embodiment, assuming that the PLCA device <NUM> enters the emergency transmission mode when the PLCA device <NUM> executes the transmission opportunity <NUM>, the PLCA device <NUM> may suspend the packet transmission corresponding to at least one of the PLCA devices <NUM> to 1N (whose transmission priority is lower than the PLCA device <NUM>) according to the previous teaching, so as to shorten at least one of the transmission opportunities <NUM>-21N.

Then, after the transmission opportunity 21N ends, the transmission opportunity <NUM> will start again. In this case, since the transmission priority of the PLCA device <NUM> is higher than that of the PLCA device <NUM>, the PLCA device <NUM> will wait for the PLCA device <NUM> to complete the corresponding packet transmission. That is, the PLCA device <NUM> does not attempt to shorten the transmission opportunity <NUM> by, for example, sending interference packets. Similarly, since the transmission priorities of the PLCA devices <NUM> and <NUM> are higher than that of the PLCA device <NUM>, the PLCA device <NUM> will wait for the PLCA devices <NUM> and <NUM> to complete the corresponding packet transmission. That is, the PLCA device <NUM> does not attempt to shorten the transmission opportunities <NUM> and <NUM> by, for example, sending interference packets.

After the transmission opportunity <NUM> ends, the PLCA device <NUM> may send the required emergency packet in the corresponding transmission opportunity <NUM>. Since at least one of the transmission opportunities <NUM> to 21N is shortened according to the above teaching, the transmission opportunity <NUM> may be started earlier, and the waiting time of the PLCA device <NUM> may be shortened.

Claim 1:
A physical layer collision avoidance device (<NUM> to 1N), belonging to a physical layer collision avoidance network (<NUM>), wherein the physical layer collision avoidance device (<NUM> to 1N) comprises:
a communication circuit (<NUM>); and
a controller (<NUM>), coupled to the communication circuit (<NUM>) and configured to:
in response to determining that the physical layer collision avoidance device (<NUM> to 1N) enters an emergency transmission mode, find a first physical layer collision avoidance device that is performing a corresponding first packet transmission;
in response to determining that a first transmission priority of the first physical layer collision avoidance device is lower than a transmission priority of the physical layer collision avoidance device, suspend the first packet transmission of the first physical layer collision avoidance device by controlling the communication circuit (<NUM>) to send an interference packet in the physical layer collision avoidance network (<NUM>); and
in response to determining that it is the physical layer collision avoidance device's (<NUM> to 1N) turn to perform a corresponding packet transmission, control the communication circuit (<NUM>) to send at least one emergency packet corresponding to the emergency transmission mode,
wherein the physical layer collision avoidance network (<NUM>) comprises the physical layer collision avoidance device (<NUM> to 1N) and at least one other physical layer collision avoidance device (<NUM> to 1N), and the physical layer collision avoidance device (<NUM> to 1N) and the at least one other physical layer collision avoidance device (<NUM> to 1N) respectively perform corresponding packet transmission in the physical layer collision avoidance network (<NUM>) according to corresponding transmission opportunities (<NUM> to 21N),
the physical layer collision avoidance network (<NUM>) characterized in that
the controller (<NUM>) is further configured to:
determine a current transmission opportunity, and accordingly determine the first physical layer collision avoidance device that is currently performing the corresponding first packet transmission;
in response to determining that the current transmission opportunity belongs to the physical layer collision avoidance device (<NUM> to 1N), determine that it is the physical layer collision avoidance device's (<NUM> to 1N) turn to perform the packet transmission.