WO2022228639A1

WO2022228639A1 - Method and system for a communications network

Info

Publication number: WO2022228639A1
Application number: PCT/EP2021/060780
Authority: WO
Inventors: Sujan Pandey
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2022-11-03
Also published as: CN117203945A

Abstract

A method for controlling a communication link between a first physical layer device and a second physical layer device in a communication network of a platform is provided. The method comprises, at the first physical layer device accessing a first data register comprising one or more data values indicative of a fault status of the first physical layer device, accessing a second data register comprising one or more data values indicative of a fault status of the second physical layer device, evaluating a signal quality of the communication link and controlling the communication link at the first physical layer device based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality.

Description

METHOD AND SYSTEM FOR A COMMUNICATIONS NETWORK

TECHNICAL FIELD

The present disclosure relates to methods and systems for communications networks. In particular, the methods and systems described herein relate to operation of a communication link in a communications network.

BACKGROUND

Modern vehicles comprise an increasingly sophisticated array of sensors, onboard computers and other types of hardware devices. These devices are controlled by centralised Electronic Control Units (ECUs) that act brains for the vehicle. ECUs obtain sensor data and communicate instructions to other devices across an In-Vehicle Network (IVN).

Centralisation of control to ECUs minimizes the complexity of computation at nodes in the IVN because individual devices do not have to perform data analysis to determine their next operation. However, the safe operation of the vehicle depends on ensuring proper functioning of the network to ensure that the correct instructions are received at the nodes, from the ECUs. SUMMARY

It is an object of the present disclosure to provide a method for controlling a communication link between a first physical layer device and a second physical layer device in a communication network such as In-Vehicle Network.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

According to a first aspect, a method for controlling a communication link between a first physical layer device and a second physical layer device in a communication network of a platform is provided. The method comprises, at the first physical layer device accessing a first data register comprising one or more data values indicative of a fault status of the first physical layer device, accessing a second data register comprising one or more data values indicative of a fault status of the second physical layer device, evaluating a signal quality of the communication link and controlling the communication link at the first physical layer device based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality.

The method according to the first aspect establishes the fault status of a communication link between PHY devices in a communication network based on information that is stored or determined locally by one of the PHY devices.

According to a second aspect a node in a communication network of a platform is provided. The node comprises a physical layer device comprising a first data register configured to store data indicative of a fault status of the physical layer device and a second data register configured to store data indicative of a fault status of a second physical layer device in communication with the physical layer device through a communication link. The physical layer device is configured to access one or more data values stored in the first register, access one or more data values stored in the second register, evaluate a signal quality of the communication link between the physical layer device and the second physical layer device and control the communication link based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality. According to a third aspect, an electronic control unit (ECU) for a communication network in a platform is provided. The electronic control unit comprises a processor; and a memory communicatively coupled with the processor. The memory stores instructions that when implemented on the processor cause the processor to receive a fault status of a communication link in the communication network determine a mode of operation for the platform at the ECU based on the fault status of the communication link and control the platform to operate in the determined mode of operation.

In an implementation form evaluating the signal quality comprises comparing the signal to noise ratio of the communication link to a pre-determined threshold value.

In a further implementation form controlling the communication link at the first physical layer device comprises restarting the communication link at the first physical layer device in response to determining that the signal to noise ratio is below the pre-determined threshold. The method according to the first and second implementation forms may be used to establish whether the signal quality is at an acceptable level and take an appropriate action when the signal quality is below an acceptable level.

In a further implementation form controlling the communication link comprises operating the first physical layer device in a failsafe mode in response to determining that at least one of the data values of the first data register or the second data register indicates a fault is present at the first physical layer device or the second physical layer device.

In a further implementation form operating the device in a failsafe mode comprises suspending operations at the first physical layer device. The method may be to operate a communication network in response to detecting that either one of a pair of PHY devices in a communication link are not functioning properly.

In a further implementation form the method comprises determining whether the communication link is active.

In a further implementation form the method comprises restarting the communication link after a period of time has elapsed.

The method may be used to restore a communication link where a temporary or transient fault has caused a PHY device to function improperly, but the communication link is still active between the PHY device and a link partner.

In a further implementation form the method comprises outputting a fault status indicative of a permanent fault in the communication link in response to determining that the communication link is inactive.

In a further implementation form the method comprises communicating the fault status of the communication link to a further node of the communication network.

In a further implementation form the further node comprises an Electronic Control Unit (ECU).

In a further implementation form the method comprises determining a mode of operation for the platform at the ECU based on the fault status of the communication link and controlling the platform to operate in the determined mode of operation.

In a further implementation form the method comprises establishing a back-up communication link in the communication network in response to receiving the fault status indicative of a permanent fault. The method provides a method for safe operation of a vehicle where a communication link in the In-Vehicle Network has permanently failed.

In a further implementation form the method comprises determining one or more further data values indicative of a fault status of the first physical layer device or the second physical layer device and writing the one or more further data values to the first data register or the second data register.

These and other aspects of the present disclosure will be apparent from and the embodiment(s) described below. BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

Fig. 1 shows a schematic diagram of a communications network, according to an example.

Fig. 2 shows a schematic diagram of a node in a communications network, according to an example.

Fig. 3 shows a schematic diagram of a communications network, according to an example. Fig. 4 shows a block diagram of a method for controlling a communication link in a communications network, according to an example.

Fig. 5 shows a block diagram of a method for a communications network, according to an example.

Fig. 6 shows a simplified schematic diagram of a computing system, according to an example.

DETAILED DESCRIPTION

Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.

Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate. The terminology used herein to describe embodiments is not intended to limit the scope. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document should not preclude the presence of more than one referent. In other words, elements referred to in the singular can number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 is a schematic diagram of a communications network 100, according to an example. The communications network 100 comprises a first node 105 and a second node 110. The first node 105 and second node 110 are in communication via a communication channel 115.

According to examples described herein the communication network 100 may form part of an in-vehicle network (IVN). The communications network 100 may be used to enable communications between, for example, electronic control units (ECUs) including engine control modules (ECMs), power train control module (PCMs), lights, sensors, airbags, safety features, steering control, brake systems and other vehicle components.

Each of the nodes 105, 110 comprise a physical layer device 120, 125 herein referred to as a PHY device. The PHY devices 120, 125 are configured to implement physical layer operations according to the Open Systems Interconnection (OSI) model. In particular, the PHY devices 120, 125 are configured to transmit and receive data across a physical medium provided by the communication channel 115.

Each PHY device 120, 125 is communicatively coupled to a microcontroller 130, 135. In examples, the microcontrollers 130, 135 may be implemented as digital signal processors (DSPs) and/or central processing units (CPUs). Microcontrollers 130, 135 are configured to implement at least data link layer operations according to the OSI model. The data link layer provides node-to-node data transfer and defines protocols to establish and terminate a connection between two physically connected devices. The data link layer may be subdivided into the Medium access control (MAC) layer that controls how devices gain access to the physical medium and permission to transmit data and the Logical link control (LLC) layer that encapsulates network layer protocols, and controls error checking and frame synchronization.

A representation 140 of the OSI model is depicted in Fig. 1. The representation 140 comprises the physical layer 145 implemented by the PHY devices 120, 125, the data link layer 150 also referred to herein as layer 2 and implemented by the microcontrollers 130, 135, the network layer 155, the transport layer 160, the session layer 165, the presentation layer 170 and the application layer 175. In some cases, in addition to layer 2 operations, the microcontrollers 130, 135 may be configured to implement operations from one or more higher layers 180.

When data is received by PHY device 120, the PHY device 120 converts an analog signal from the communication channel 115 to a digital signal that may be interpreted as a stream of bits by the microcontroller 130. Conversely, the PHY device 120 may receive data bits to transmit from the microcontroller 130 and convert the bits into an analog signal for transmission to the PHY device 125 via the communication channel 115. The microcontroller 130 encapsulates data in frames according to a data link layer protocol where a frame comprises a header and a data packet of bits.

Fig. 2 is a schematic diagram of a node 200, according to an example. The node 200 comprises a microcontroller 210, and a PHY device 220, similar to microcontrollers 130, 135 and PHY devices 120, 125 of the nodes 105, 110 shown in Fig. 1.

The PHY device 220 comprises control logic 230. The control logic 230 is arranged to execute instructions for performing physical layer operations in the PHY device 220. The control logic 230 is communicatively coupled to a memory register 240. The memory register 240 may contain machine readable instructions for control logic 230. The PHY device 220 further comprises a logical component 250 that is arranged to implement a

Physical Coding Sublayer that interfaces with the MAC sublayer implemented by the microcontroller 210 and a Physical Medium Attachment sublayer that interfaces directly with the physical medium provided by a communication channel. The logical component 250 may execute instructions to perform symbol encoding, decoding, transmission and reception of data through the communication channel 260, under the control of the control logic 230.

In Fig. 2, the control logic 230 is communicatively coupled to an Operations, Administration and Management (OAM) encoder module 260 and an OAM decoder module 270. The OAM encoder module 260 is arranged to insert OAM data into a bit stream from the microcontroller 210. In particular, an OAM word comprising a plurality of OAM bits may be inserted into a frame received from the microcontroller 210. An OAM word may comprise bits of data that are communicated between PHY devices at nodes of a communications network. The OAM decoder module 270 is arranged to extract OAM bits from bit streams received at the logical component 250 from the communication channel 260.

According to examples described herein an OAM word may comprise a global message that is communicated to all PHY devices in a communications network across all nodes. In examples an OAM word may comprise a local message which is exchanged between a pair of PHY devices in a communications network. In examples, an OAM word may comprise a “query on demand” message comprising a request from one PHY device to another PHY device for information. All PHY devices in a communication network implement instructions to decode and interpret messages and, where required, perform actions based on the messages such as communicating data to a link partner in response to a query on demand or executing an action at the node.

The PHY device 220 further comprises a local PHY status register 280. The local PHY status register 280 is communicatively coupled to the control logic 230. According to examples described herein faults may occur at the physical layer. The local PHY status register 280 is arranged to store data indicative of a fault status of the PHY device 220. The control logic 230 may read and write data indicative of a fault status to the local register 280 as a result of the node 200 performing tests. In examples tests may include a Near-end Physical Coding Sublayer (PCS) loopback test that indicates whether the PCS of the PHY device 220 is functioning or not. A Near-end Physical Medium Attachment (PMA) loopback test indicates whether the PMA sublayer of the PHY device 220 is functioning properly. A Far-end loopback indicates whether the cable and connector are functioning properly. Cable Short or Open circuit tests indicate a circuit condition. An Under Voltage Supply test may determine a low voltage condition. In some cases, tests may be initiated and/or controlled from a higher layer in the network stack.

The PHY device 220 further comprises a remote PHY status register 290. The remote PHY status register 290 is communicatively coupled to the control logic 230. According to examples, the remote PHY status register 290 may store data indicative of a fault status of one or more other PHY devices in communication with the PHY device 220.

According to examples, data from registers 280, 290 may be communicated to link partners in communication with the node 200. Content of the registers 280, 290 may be received and/or transmitted to link partners using OAM words. In examples, the PHY device 220 further comprises a global register (not shown in Fig. 2) comprising data relating to the state of the network and other relevant information such as whether nodes are out of order.

Fig. 3 is a schematic diagram of a communications network 300, according to an example. The communications network 300 may form part of an in-vehicle network (IVN) for a vehicle or other platform similar to the communications network 100 shown in Fig. 1.

The communications network 300 shown in Fig. 3 comprises an ECU 305. The ECU 305 may be an engine control module, powertrain control module, transmission control module, a brake Control module, central control module, central timing module, general electronic module, body control module, suspension control module, a control unit, or a control module or any other form of ECU.

The communications network 300 further comprises sensors 310, 315, 320. The sensors 310, 315, 320 may comprise cameras, radar, GPS or any other kind of sensor for a vehicle. The ECU 305 comprises a central processing unit 325 that is arranged to receive sensor data from the sensors 310, 315, 320 across the communication network 300 and perform actions in response to the sensor data.

In the example shown in Fig. 3, the communications network 300 further comprises a brake control module 330. The brake control module 330 is arranged to control a brake actuator based on data received over the communication network 300 from the ECU 305. For example, in the case that the sensor 320 is a camera that detects an obstruction in front of the vehicle, the central processing unit 325 may cause a control signal to be generated and communicated to the brake control module 330 to actuate the brake. In the example shown in Fig. 3, each of the sensors 310, 315, 320, the ECU 305 and the brake control module 330 comprise a PHY device 335, 340, 345, 350, 355 similar to PHY device 220 previously described and shown in Fig. 2. Furthermore, each of nodes 305,

310, 315, 320, 330 implements higher level network layers (layer 2 or above) in a microcontroller, processor or similar to microcontroller 210 shown in Fig. 2.

The communications network 300 further comprises network switches 360, 365. The network switch 360 comprises PHY devices 361, 362, 363 that connect to communications links to the ECU 305, network switch 370 and sensor 320 respectively. Similarly, the network switch 370 comprises PHY device 371 , 372, 373, 374 that connect to communications links to the network switch 360, the brake control module 330, the sensor 310 and the sensor 315, respectively.

The network switches 360, 370 are layer 2 devices that connect different devices in the communications network 300 using MAC addresses to forward data at the data link layer. In particular, network switches 360, 370 may comprise a microcontroller to perform data link layer operations however they are not configured to perform higher layer operations such as network layer operations involving e.g. TCP/IP protocols. In other words, the network switches 360. 365 are “dumb” switches that are blind to processing of data packets higher up in the network stack.

The PHY devices 335, 340, 345, 350, 355, 361, 362, 363, 371, 372, 373, 374 shown in Fig. 3 may communicate with each other using OAM operations. In particular, global messages may be communicated to all the PHY devices and local messages may be communicated in OAM words between link partners. For example, the PHY device 372 in switch 370 may communicate a local OAM message to its link partner PHY device 355 in the brake control module 330. The PHY device 350 may be controlled to communicate a global message in an OAM word to all PHY devices.

In in-vehicle networks such as communications network 300, faults may occur in the physical layer that disrupt the normal safe functioning of the vehicle. For example, in the network shown in Fig. 3, the ECU 305 may receive an indication of an obstruction in the road ahead, and send a brake command to the brake control module 330. If either of PHY devices 372, 355 or the communication link between the PHY device 372 and PHY device 355 has failed then the brake command is not received and the vehicle will not stop.

Fig. 4 is a block diagram of a method 400 for controlling a communication link between a first PHY device and a second PHY device in a communication network. The method 400 may be implemented in the communications network 300 shown in Fig. 3. For example, the method 400 may be performed between the PHY devices 372, 355.

At block 410, the method 400 comprises accessing a first data register comprising one or more data values indicative of a fault status of the first physical layer device. According to examples, when the method 400 is implemented by the PHY device 372, the PHY device 372 may access its own local PHY status register to obtain data indicative of the fault status of the PHY device 372. In examples, the data may comprise data from a Near-end PCS loopback test, a Near-end PMA loopback test, a Far-end loopback and/or a cable short or open circuit test and/or a Under voltage supply test that is carried out with the PHY device 355.

At block 420, the method 400 comprises accessing a second data register comprising one or more data values indicative of a fault status of the second physical layer device. For example, when the method 400 is implemented by the PHY device 372, the PHY device 372 may access the remote PHY status register that contains data indicative of a fault status of the PHY device 355.

At block 430, the method 400 comprises evaluating a signal quality of the communication link. In Fig. 3, the PHY device 372 may evaluate the signal quality of the communication link with the PHY device 355. In examples, evaluating the signal quality may comprise comparing the signal to noise ratio of the communication link to a pre-determined threshold value.

At block 440, the method 400 comprises controlling the communication link at the first physical layer device based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality. According to examples, controlling the communication link at the first physical layer device comprises restarting the communication link at the first physical layer device in response to determining that the signal to noise ratio is below the pre-determined threshold.

According to an example, controlling the communication link comprises operating the first physical layer device to in a failsafe mode in response to determining that at least one of the data values of the first data register or the second data register indicates a fault is present at the first physical layer device or the second physical layer device.

For example, a data value in the remote PHY status register of the PHY device 372 may indicate that the PMA sublayer of the PHY device 355 is not functional. In that case, the PHY device 372 may operate in failsafe mode. According to examples, operating in a failsafe mode may comprise suspending operations at the PHY device. In examples, the method 400 may further comprise determining whether the communication link is active i.e. whether data is still being communicated between the

PHY devices. If the communication is still active the PHY device may restart the link after a period of time has elapsed as the fault may be temporary or transient. Otherwise, if the communication link is inactive, the PHY device may output data indicating a permanent fault is present.

In some cases, the fault status of the PHY devices and/or the communication link may be communicated back to the ECU 305 to allow the ECU 305 to take further action. In some cases, the ECU 305 may switch to a different mode of operation in response to data received from PHY devices in the communication link. For example, if the link between PHY devices 372, 355 has failed, the PHY device 372 may communicate this information back to the ECU 305, which may then decide to operate the vehicle in a failsafe or back-up mode. This may include establishing a back-up link to the brake control module 330, for example. According to examples, the local and remote PHY status registers of all PHY devices may be updated periodically e.g. by PHY devices performing tests with other PHY devices in the network. The PHY devices may communicate data from the registers to one another using the OAM function. Hence, all PHY devices may store an up to date copy of health information relating to their link partners in the network. Fig. 5 is a block diagram showing a method 500, according to an example. The method 500 may be used in conjunction with the other examples and methods described herein and in particular with method 400 shown in Fig. 4. The method 500 may be implemented on a PHY device such as the PHY device 220 shown in Fig. 2.

The method 500 may be used to determine the response of a PHY device to a fault based on an overall health status. The health status may be assessed by continuously monitoring the relevant local and remote PHY status registers of the local PHY device and signal quality of a communication link between the local and remote PHY devices.

According to examples described herein a four-tier classification {1, -1, -2, -3} may be used to represent different health statuses of PHY devices and connections based on whether the health status is good (1) or whether a transient fault (-1), temporary fault (- 2) or permanent fault (-3) exists. In examples, health status may be stored in a dedicated health status register in the PHY device. When the health status is “+1”, data values in the local PHY status register and remote

PHY status register indicate that the PHY devices are functioning properly and signal quality is good indicating that overall health status is good.

The health status is “-1” if the values in the local and remote PHY status registers indicate that the local and remote PHY devices are functioning properly but signal quality is degrading and has fallen below a threshold. In this case, the fault is transient because the signal quality may improve.

The health status indicates “-2” if at least one of the data values in the local and/or remote PHY status registers indicate that there is an issue with one of the PHY devices. Data received at the PHY device may be incorrect but the link between PHY devices is still alive. In this case, the fault may be temporary and may be fixed after a time interval has elapsed.

The health status indicates “-3” if at least one of the data values in the local and/or remote PHY status registers indicate that there is an issue with one of the PHY devices and there is no active link between PHY devices. In this case the fault is permanent and may be due to a supply loss, under voltage, permanent contact loss of a cable or connector, or a cable is short circuited or broken.

At block 510 the method comprises determining whether the health status is good at the PHY device. In other words, whether health status is +1, based on the above classification. If Yes, then the PHY device continues to monitor the PHY status registers and link quality.

If No, then at block 520 the PHY device determines whether the fault is transient, based on the health status i.e. whether the health status is -1. If Yes, then at block 530, the PHY device determines whether the signal quality has improved after a brief period of time has elapsed. If the signal quality has improved after a brief period of time then the PHY device may return the health status to +1 to indicate that the link quality is good and the registers indicate no issues with the PHY devices.

If the fault is not transient or the signal quality does not improve after a brief period of time has elapsed, the PHY device operate in a fail safe mode at block 540. At block 550, the PHY devices determines whether the fault is temporary i.e whether the health status is -2. If Yes, then at block 560, the PHY device waits for a random time interval for the temporary fault to resolve. If No, then at block 570 the PHY device determines whether the fault is permanent i.e. whether the health status is -3. If the fault is permanent then at block 580, the link is repaired. In some cases, this may comprise physically repairing the link or re-routing data through a different link. At block 590, the communications link is restarted at the health status is returned to +1.

The methods described herein allow a PHY device to establish the fault status of a PHY device and a connection with another network node. This health status information may be sent back to the ECU to allow the ECU to take appropriate action. The methods described herein utilise PHY layer OAM messaging techniques and testing. This reduces latency and processing power and provides a convenient method for PHY device monitoring for In-Vehicle Network functional safety.

The present disclosure is described with reference to flow charts and/or block diagrams of the method, devices and systems according to examples of the present disclosure. Although the flow diagrams described above show a specific order of execution, the order of execution may differ from that which is depicted. Blocks described in relation to one flow chart may be combined with those of another flow chart. In some examples, some blocks of the flow diagrams may not be necessary and/or additional blocks may be added. It shall be understood that each flow and/or block in the flow charts and/or block diagrams, as well as combinations of the flows and/or diagrams in the flow charts and/or block diagrams can be realized by machine readable instructions.

The machine-readable instructions may, for example, be executed by a general-purpose computer, a special purpose computer, an embedded processor or processors of other programmable data processing devices to realize the functions described in the description and diagrams. In particular, a processor or processing apparatus may execute the machine-readable instructions. Thus, modules of apparatus may be implemented by a processor executing machine-readable instructions stored in a memory, or a processor operating in accordance with instructions embedded in logic circuitry. The term 'processor' is to be interpreted broadly to include a CPU, processing unit, logic unit, or programmable gate set etc. The methods and modules may all be performed by a single processor or divided amongst several processors. Such machine- readable instructions may also be stored in a computer readable storage that can guide the computer or other programmable data processing devices to operate in a specific mode.

Such machine-readable instructions may also be loaded onto a computer or other programmable data processing devices, so that the computer or other programmable data processing devices perform a series of operations to produce computer- implemented processing, thus the instructions executed on the computer or other programmable devices provide an operation for realizing functions specified by flow(s) in the flow charts and/or block(s) in the block diagrams.

Fig. 6 is a block diagram of a computing system 600 that may be used for implementing the methods, devices and systems disclosed herein. Specific devices may utilize all of the components shown or only a subset of the components, and levels of integration may vary from device to device. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 600 includes a processing unit 602. The processing unit includes a central processing unit (CPU) 614, a graphics processing unit (GPU) 616, a memory 608, and may further include a mass storage device 604, a video adapter 610, and an I/O interface 612 connected to a bus 618.

The bus 618 may be one or more of any type of several bus architectures including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 614 and GPU 616 may comprise any type of electronic data processors. The memory 608 may comprise any type of non-transitory system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In an embodiment, the memory 508 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs. The mass storage 604 may comprise any type of non-transitory storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 618. The mass storage 604 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive. The video adapter 610 and the I/O interface 612 provide interfaces to couple external input and output devices to the processing unit 602. As illustrated, examples of input and output devices include a display 620 coupled to the video adapter 610 and a mouse, keyboard, or printer 622 coupled to the I/O interface 612. Other devices may be coupled to the processing unit 602, and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface for an external device.

The processing unit 602 also includes one or more network interfaces 606, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 606 allow the processing unit 602 to communicate with remote units via the networks. For example, the network interfaces 606 may provide wireless communication via one or more transmitters/transmit antennas and one or more receivers/receive antennas. In an embodiment, the processing unit 602 is coupled to a local-area network 624 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. The present disclosure can be embodied in other specific apparatus and/or methods. The described embodiments are to be considered in all respects as illustrative and not restrictive. In particular, the scope of the invention is indicated by the appended claims rather than by the description and Figs herein. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A method for controlling a communication link between a first physical layer device and a second physical layer device in a communication network of a platform, the method comprising, at the first physical layer device: accessing a first data register comprising one or more data values indicative of a fault status of the first physical layer device; accessing a second data register comprising one or more data values indicative of a fault status of the second physical layer device; evaluating a signal quality of the communication link; and controlling the communication link at the first physical layer device based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality.

2. The method of claim 1 , wherein evaluating the signal quality comprises comparing the signal to noise ratio of the communication link to a pre-determined threshold value.

3. The method of claim 2, wherein controlling the communication link at the first physical layer device comprises restarting the communication link at the first physical layer device in response to determining that the signal to noise ratio is below the pre determined threshold.

4. The method of claim 1 , wherein controlling the communication link comprises operating the first physical layer device in a failsafe mode in response to determining that at least one of the data values of the first data register or the second data register indicates a fault is present at the first physical layer device or the second physical layer device.

5. The method of claim 4, wherein operating the device in a failsafe mode comprises suspending operations at the first physical layer device.

6. The method of claim 4, further comprising determining whether the communication link is active.

7. The method of claim 6, comprising restarting the communication link after a period of time has elapsed.

8. The method of claim 6, comprising outputting a fault status indicative of a permanent fault in the communication link in response to determining that the communication link is inactive.

9. The method of claim 8, further comprising communicating the fault status of the communication link to a further node of the communication network.

10. The method of claim 9, wherein the further node comprises an Electronic Control Unit (ECU).

11. The method of claim 10, comprising: determining a mode of operation for the platform at the ECU based on the fault status of the communication link; and controlling the platform to operate in the determined mode of operation.

12. The method of claim 8, further comprising establishing a back-up communication link in the communication network in response to receiving the fault status indicative of a permanent fault.

13. The method of claim 1, comprising: determining one or more further data values indicative of a fault status of the first physical layer device or the second physical layer device and writing the one or more further data values to the first data register or the second data register.

14. A node in a communication network of a platform, the node comprising:

A physical layer device comprising a first data register configured to store data indicative of a fault status of the physical layer device; a second data register configured to store data indicative of a fault status of a second physical layer device in communication with the physical layer device through a communication link; wherein the physical layer device is configured to: access one or more data values stored in the first register; access one or more data values stored in the second register; evaluate a signal quality of the communication link between the physical layer device and the second physical layer device, control the communication link based on the one or more data values of the first data register, the one or more data values of the second data register and the signal quality.

15. The node of claim 14, wherein the physical layer device is configured to compare the signal to noise ratio of the communication link to a pre-determined threshold value.

16. The node of claim 14, wherein to control the communication link the physical layer device is configured to restart the communication link in response to determining that the signal to noise ratio is below the pre-determined threshold.

17. The node of claim 14, wherein to control the communication link the physical layer device is configured to operate in a failsafe mode in response to determining that at least one of the data values of the first data register or the second data register indicates a fault is present at the first physical layer device or the second physical layer device.

18. The node of claim 14 wherein the physical layer device is configured to determine whether the communication link is active.

19. The node of claim 18, wherein the physical layer device is configured to restart the communication link after a period of time has elapsed.

20. An electronic control unit (ECU) for a communication network in a platform, the electronic control unit comprising: a processor; and a memory communicatively coupled with the processor, the memory storing instructions that when implemented on the processor, cause the processor to: receive a fault status of a communication link in the communication network; determine a mode of operation for the platform at the ECU based on the fault status of the communication link; and control the platform to operate in the determined mode of operation.