Patent Description:
Systems in automobiles nowadays have a large number of devices called electronic control units (hereinafter referred to as ECUs). The network that interconnects these ECUs is called the in-vehicle network. There are a large number of standards for the in-vehicle network, among which a standard called CAN (Controller Area Network (registered trademark)) is generally used. Note that the communication speed of CAN is low, which is about <NUM> Mbps maximum.

Meanwhile, it is expected that the number of ECUs used in the in-vehicle network will further increase for realization of fully automated driving. In light of this, it can be said that CAN has a limitation because its communication speed is low. Thus, to increase the communication speed of the in-vehicle network, there is a move afoot to apply Ethernet (registered trademark), the performance of which has been proved as a general information network, typically on the Internet, to the in-vehicle network. Since Ethernet (registered trademark) has a communication speed of <NUM> Mbps which is <NUM> times that of CAN, it is expected to be a technology replacing CAN. Here, Ethernet (registered trademark) has problems to be solved, in other words, weak points, in terms of real-time communication and safety of the communication in order to use it in the in-vehicle network.

To compensate for the weak points of Ethernet (registered trademark), proposed is Ethernet AVB/TSN (audio video bridging/time sensitive networking) having enhanced functions for time synchronization, a bandwidth guarantee, and a delay guarantee. Since an enormous amount of data is handled in fully automated driving, the in-vehicle network must be able to process a large volume of data, such as data from various sensors and video data, simultaneously and parallelly. Since Ethernet AVB/TSN is capable of processing a large volume of data simultaneously and parallelly, it is effective for the use.

However, even for an in-vehicle network using Ethernet AVB/TSN, if data is handled inappropriately, it may impede fully automated driving, leading to a serious accident.

To address this, for example, Patent Literature <NUM> discloses a technique for detecting inappropriate data in Ethernet AVB/TSN. In the technique disclosed in Patent Literature <NUM>, a table is prepared in advance, having stream IDs included in IEEE1722 frames used in Ethernet AVB/TSN and the MAC addresses of the source units corresponding to the stream IDs. Then, the MAC address extracted from the stream ID included in a frame actually transmitted or received is compared with the one in the table to detect inappropriate data.

Patent Literature <NUM> relates to a network communication system which includes one or more talkers that may communicate data streams to one or more listeners over a network, such as an Ethernet Audio/Video Bridging network. Before transmitting a new data stream, a talker may request a reservation for bandwidth through a controller that is configured to manage and/or control the flow of data streams over the network. If there is not enough bandwidth, then the controller may determine whether any existing data streams may be transmitted at lower bandwidths to make available enough bandwidth for the new data stream. Alternatively, the controller may determine whether any existing data streams having lower priorities than the new data stream may be terminated to make available enough bandwidth for the new data stream.

Patent Literature <NUM> relates to a communication system and methods of using the system. The communication system includes: a plurality of electronic control units (ECUs) operably configured for a first protocol and a second protocol; one or more switches; a first network of connections; and a second network of connections. The first protocol may be an audio video bridging (AVB) protocol. The ECUs may include: a first protocol interface that includes one or more AVB ports; a second protocol interface; memory storing traffic shaping instructions; and a processor configured to carry out the traffic shaping instructions. The one or more switches may have a plurality of AVB ports. The first network of connections may interconnect the ports of the plurality of ECUs and the ports of the one or more switches. The second network of connections may interconnect the second protocol interfaces of at least some of the plurality of ECUs.

The technique in Patent Literature <NUM> is capable of detecting inappropriate data on a frame basis but, unfortunately, incapable of detecting whether the bandwidth, which is a network bandwidth necessary for transmitting and receiving data, is appropriately reserved. Therefore, if a service reserves and uses an inappropriately large bandwidth for data communication via the in-vehicle network, the in-vehicle network will be occupied inappropriately, resulting in a problem that other services cannot communicate. This situation will occur not only in mobility networks in automobiles but also those in construction machines, agricultural machines, ships, trains, airplanes, and the like.

The present disclosure has been made in light of the above situation, and thus, an object thereof is to provide a network monitor and the like capable of determining whether the reservation of a bandwidth in a communication path of a mobility network is inappropriate.

The invention is defined by the subject matter of the independent claims specifying an "in-vehicle network" used in a "vehicle". The broader terms "mobility network" and "mobility entity" are used in conjunction with illustrative examples. Further advantageous features are set out in the appended dependent claims.

A network monitor according to an example is a network monitor for a mobility network that includes multiple electronic control units and is used in a mobility entity, the network monitor being included in each of one or more repeaters that, together with a source unit and a destination unit, form a communication path in the mobility network, each of the source unit, the destination unit, and the one or more repeaters being one of the electronic control units, the network monitor comprising: a receiver that receives an announcement transmitted by the source unit using a mechanism for bandwidth reservation, the announcement including a value of a first bandwidth for the source unit to perform first data communication; a database that holds a white list in which a second bandwidth is specified on a data communication type basis; a determiner that determines whether to reserve the first bandwidth by comparing the value of the first bandwidth with the second bandwidth for the first data communication specified in the white list; a bandwidth reserver that reserves the first bandwidth depending on a determination result of the determiner; and a transmitter that transmits the determination result of the determiner.

It should be noted that these general or specific aspects may be implemented as a system, a method, an integrated circuit, a computer program, or a computer readable recording medium such as CD-ROM, or may be implemented as any selective combination thereof.

The network monitor and the like according to the example is capable of determining whether the reservation of a bandwidth in a communication path of a mobility network is inappropriate.

A network monitor according to an example of the present disclosure is a network monitor for a mobility network that includes multiple electronic control units and is used in a mobility entity, the network monitor being included in each of one or more repeaters that, together with a source unit and a destination unit, form a communication path in the mobility network, each of the source unit, the destination unit, and the one or more repeaters being one of the electronic control units, the network monitor comprising: a receiver that receives an announcement transmitted by the source unit using a mechanism for bandwidth reservation, the announcement including a value of a first bandwidth for the source unit to perform first data communication; a database that holds a white list in which a second bandwidth is specified on a data communication type basis; a determiner that determines whether to reserve the first bandwidth by comparing the value of the first bandwidth with the second bandwidth for the first data communication specified in the white list; a bandwidth reserver that reserves the first bandwidth depending on a determination result of the determiner; and a transmitter that transmits the determination result of the determiner.

Here, for example, the white list includes a parameter, on a data communication type basis, indicating a normal band value and an abnormality judgment value that specify the second bandwidth.

In addition, for example, the determiner may compare the value of the first bandwidth with the parameter included in the white list and determines whether to reserve the first bandwidth depending on whether the value of the first bandwidth is included in a range of the second bandwidth specified by the normal band value and the abnormality judgment value.

Here, for example, the determiner may store data indicating whether the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, in a storage as a log of the determination result.

In addition, for example, when the determiner determines that the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the bandwidth reserver may reserve the first bandwidth.

In addition, for example, when the determiner determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the operation of the bandwidth reserver may be such that it does not reserve the first bandwidth.

In addition, for example, the determiner may further determine an operating state of the mobility entity, the determination result may include the operating state of the mobility entity, and when the operating state of the mobility entity is a driving state, the bandwidth reserver may reserve the first bandwidth even if the determiner determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value.

In addition, for example, the determiner may further determine an operating state of the mobility entity, and when the determiner determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, and the operating state of the mobility entity is a driving state, the network monitor may transmit to the mobility entity an instruction to slow down and then stop the mobility entity.

In addition, for example, the determiner may further determine an operating state of the mobility entity, and when the determiner determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, and the operating state of the mobility entity is a state where an automated driving function or a driving assistance function is in operation, the network monitor may transmit to the mobility entity an instruction to stop the automated driving function or the driving assistance function.

In addition, for example, the transmitter may transmit the determination result of the determiner to the source unit.

In addition, for example, when the determiner determines that the first bandwidth is to be reserved, the network monitor may forward the value of the first bandwidth to a next repeater on the communication path or the destination unit.

Here, for example, the mechanism for bandwidth reservation may be a mechanism in Ethernet AVB/TSN.

Each embodiment described below illustrates a specific example of the present disclosure. Numeral values, shapes, constituents, steps, the order of steps, and the like shown in the following embodiment are examples and not intended to limit the present disclosure. Among the constituents in the following embodiments, the constituents not stated in independent claims indicating the highest concept are described as optional constituents. In addition, any combination of elements from all the embodiments may be formed.

Hereinafter, with reference to the drawings, description is provided for a network monitor and the like in an embodiment.

<FIG> is a diagram illustrating an example of the overall configuration of an in-vehicle network according to the present embodiment.

The in-vehicle network illustrated in <FIG> has multiple electronic control units (ECUs) and is mounted on a vehicle <NUM>. In the example illustrated in <FIG>, the in-vehicle network in the vehicle <NUM> is constituted of, for example, an Ethernet <NUM> and a CAN bus <NUM>. Note that the in-vehicle network in the vehicle <NUM> may be constituted of only the Ethernet <NUM>.

To a central gateway <NUM> is connected an Ethernet-CAN gateway <NUM>, telematics control unit <NUM>, information system DCU (domain control unit) <NUM>, and automated driving system DCU <NUM>, using the Ethernet <NUM>. In the present embodiment, the central gateway <NUM> in the present embodiment corresponds to an ECU.

The telematics control unit <NUM> is a unit for the vehicle <NUM> to communicate with a cloud server <NUM> in an external network <NUM>. The telematics control unit <NUM> performs wireless communication, for example, a mobile entity phone network, Wi-Fi (registered trademark), or the like.

The information system DCU <NUM> is connected to an IVI (In-vehicle Infotainment) <NUM> with the Ethernet <NUM> and performs domain management of the information system network. In the present embodiment, the information system DCU <NUM> corresponds to an ECU.

The automated driving system DCU <NUM> is connected to an ADAS (advanced driver-assistance systems) <NUM>, LIDAR <NUM>, camera <NUM>, and DYNAMIC MAP <NUM>, using the Ethernet <NUM>. In the present embodiment, the automated driving system DCU <NUM> corresponds to an ECU. The ADAS <NUM> is a system that detects the possibility of an accident in advance to avoid the accident. The LIDAR <NUM> is for sensing obstacles outside the vehicle. The camera <NUM> captures images of the situation outside the vehicle, and the DYNAMIC MAP <NUM> receives and controls a dynamic map.

The Ethernet-CAN gateway <NUM> is disposed at a relay point between the Ethernet <NUM> and the CAN bus <NUM>. The Ethernet-CAN gateway <NUM> is provided with the CAN bus to which a mirror ECU <NUM>, window ECU <NUM>, brake ECU <NUM>, and accelerator ECU <NUM> are connected. The mirror ECU <NUM> controls opening and closing of mirrors in the vehicle <NUM>. The window ECU <NUM> controls opening and closing of windows in the vehicle <NUM>. The brake ECU <NUM> controls the braking operation of the vehicle <NUM>. The accelerator ECU <NUM> controls the speed of the vehicle <NUM>.

<FIG> is a diagram illustrating an example of the configuration of a network monitor <NUM> according to the present embodiment.

The network monitor <NUM> is an example of a network monitor in the in-vehicle network of the vehicle <NUM>. Among a source unit, a destination unit, and one or more repeaters that form a communication path in the in-vehicle network of the vehicle <NUM>, each of which corresponding to one of the multiple ECUs, the network monitor <NUM> is included in each of the one or more repeaters. In other words, the network monitor <NUM> is implemented inside the repeater <NUM> as illustrated in <FIG>.

The repeater <NUM> is one of the ECUs constituting the in-vehicle network and relays Ethernet frames of Ethernet AVB/TSN flowing in the communication path formed by the ECUs that constitute the in-vehicle network. Ethernet AVB/TSN is a standard for interconnecting multimedia devices and/or computers using an Ethernet network. This standard enables time synchronization, a bandwidth guarantee and a delay guarantee, which are weak points of Ethernet (registered trademark). Although in the present embodiment, description is provided below for the case of using a protocol in IEEE802.1Qat that in which a bandwidth necessary for the stream is reserved in advance to guarantee the bandwidth, as a mechanism to reserve a bandwidth for use, the present disclosure is not limited to this mechanism. Examples of bandwidth reservation mechanisms include a mechanism in Ethernet AVB/TSN and mechanisms specified in other standards or the like.

The network monitor <NUM> has a receiver <NUM>, database <NUM>, determiner <NUM>, bandwidth reserver <NUM>, and transmitter <NUM>, as illustrated in <FIG>.

The receiver <NUM> receives an announcement transmitted by the source unit using the mechanism for bandwidth reservation and including the value of a first bandwidth for the source unit to perform first data communication. The value of the first bandwidth included in the announcement is the value of the bandwidth that the source unit wants to reserve to perform a service.

Note that in the communication path described above, the source unit corresponds to the "takler" in the IEEE802.1Qat protocol, and transmitting an announcement corresponds to "advertise" in the IEEE802.1Qat protocol. The destination unit corresponds to the "listener" in the IEEE802.1Qat protocol.

The database <NUM> holds a white list that specifies a second bandwidth on a data communication type basis. Here, the white list includes parameters indicating a normal band value and an abnormality judgment value that specify the second bandwidth on a data communication type basis. The type of data communication indicates data that a service uses, for example, rear-camera video, a LIDAR signal, and remote-control data. The normal band value is a value of the bandwidth in normal use used by a service in the in-vehicle network, and thus the normal band value may be referred to as the second bandwidth. The abnormality judgment value is a value indicating the range of variation in a bandwidth in normal use used by a service in the in-vehicle network. In the present embodiment, the value obtained by combining the normal band value and the abnormality judgment value together is described as the second bandwidth.

<FIG> is a diagram illustrating an example of a white list that the database <NUM> according to the present embodiment holds.

The white list illustrated in <FIG> is constituted of parameters indicating the normal band value and the abnormality judgment value on a data communication type basis and thus specifies the second bandwidth. The white list illustrated in <FIG> shows the types of data communication used in the network by three types of services as an example of types of data communication, such as rear-camera video, a LIDAR signal, and remote-control data.

More specifically, in the example illustrated in <FIG>, the types of data communication used by the services are rear-camera video, a LIDAR signal, and remote-control data. For the rear-camera video, the normal band value is <NUM> Mbps (megabits par second), and the range of the normal band value is a range of plus and minus <NUM> Mbps relative to the normal band value (specifically, <NUM> Mbps to <NUM> Mbps). For the LIDAR signal, the normal band value is <NUM> Mbps, and the range of the normal band value is a range of plus and minus <NUM> Mbps relative to the normal band value. For the remote-control data, the normal band value is <NUM> Mbps, and the range of the normal band value is a range of plus and minus <NUM> Mbps relative to the normal band value.

Note that the unit of the normal band value and the abnormality judgment value is not limited to that illustrated in <FIG>. Besides bps, pps (packets par second) may be used, or units for various performance indicators for a network, such as the number of flows may also be used.

The determiner <NUM> compares the value of the first bandwidth with the second bandwidth of the first data communication specified in the white list to determine whether to reserve the first bandwidth.

For example, the determiner <NUM> may compare the value of the first bandwidth with parameters included in the white list and determine whether to reserve the first bandwidth depending on whether the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value.

In addition, for example, when the determiner <NUM> determines that one bandwidth is to be reserved, the determiner <NUM> may forward the value of the first bandwidth to the next repeater on the communication path or the destination unit.

Note that the determiner <NUM> may store in a storage the data indicating whether the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, as a log of the determination result. Although here, the storage is a memory or the like included in the determiner <NUM>, the storage may be a memory or the like included in the network monitor <NUM>.

In the present embodiment, the determiner <NUM> compares the value of the first bandwidth included in the announcement received by the receiver <NUM> with the white list which the database <NUM> holds, and notifies the transmitter <NUM> of the determination result, which is the comparison result. For example, if the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the determiner <NUM> notifies the transmitter <NUM> of the determination result indicating it. On the other hand, for example, if the first bandwidth is within the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the determiner <NUM> notifies the transmitter <NUM> of the determination result indicating it and notifies the bandwidth reserver <NUM> of the value of the first bandwidth. Then, the determiner <NUM> also forwards the announcement to the next repeater on the communication path. Note that if there is not a next repeater on the communication path but the next is the destination unit, the determiner <NUM> forwards the announcement to the destination unit.

The bandwidth reserver <NUM> reserves the first bandwidth according to the determination result of the determiner <NUM>. For example, if the determiner <NUM> determines that the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the bandwidth reserver <NUM> reserves the first bandwidth. On the other hand, for example, if the determiner <NUM> determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the bandwidth reserver <NUM> does not have to reserve the first bandwidth.

As described above, the bandwidth reserver <NUM> reserves a bandwidth on the communication path of the in-vehicle network according to the determination result reported by the determiner <NUM>.

The transmitter <NUM> transmits the determination result of the determiner <NUM>. More specifically, the transmitter <NUM> transmits the determination result to the source unit of the determiner <NUM>.

<FIG> is a diagram illustrating an example of the configuration of a communication path of the in-vehicle network according to the present embodiment.

<FIG> illustrates an example of the configuration of a communication path connecting a source unit <NUM> to a destination unit <NUM> in an in-vehicle network of the vehicle <NUM>. The communication path in <FIG> illustrates an example in which the source unit <NUM> is connected to the destination unit <NUM> via n repeaters (n is a natural number larger than or equal to one). Note that the communication path in the in-vehicle network of the vehicle <NUM> may be simply referred to as the network. Each of the source unit <NUM>, the destination unit <NUM>, and the repeaters <NUM>-<NUM> to <NUM>-n is one of the ECUs included in the in-vehicle network of the vehicle <NUM>. Each of the repeaters <NUM>-<NUM> to <NUM>-n includes the network monitor <NUM> described above thereinside.

It is assumed that to perform a service, the source unit <NUM> wants to reserve a necessary first bandwidth on the communication path illustrated in <FIG>. In this case, the source unit <NUM> transmits an announcement including the value of the first bandwidth to the repeater <NUM>-<NUM>, which is connected next to the source unit <NUM> itself.

Then, the repeater <NUM>-<NUM> performs, using the network monitor <NUM> included therein, a first bandwidth reservation determination to determine whether to reserve the first bandwidth depending on whether the first bandwidth is inappropriate. If the repeater <NUM>-<NUM> has reserved the first bandwidth properly, the repeater <NUM>-<NUM> forwards, in other words, transmits the announcement including the value of the first bandwidth to the next repeater <NUM>-<NUM>.

In the same manner, the repeater <NUM>-<NUM> performs, using the network monitor <NUM> included therein, performs the first bandwidth reservation determination. If the repeater <NUM>-<NUM> has reserved the first bandwidth properly, it transmits the announcement including the value of the first bandwidth to the next repeater <NUM>-<NUM>.

In summary, each of the repeaters <NUM>-<NUM> to <NUM>-(N-<NUM>) performs, using the network monitor <NUM> included therein, the first bandwidth reservation determination. If the repeater has reserved the first bandwidth properly, it transmits the announcement including the value of the first bandwidth to the next repeater. The repeater <NUM>-N repeats the operation of performing the first bandwidth reservation determination using the network monitor <NUM> included therein and transmitting, if the repeater <NUM>-N has reserved the first bandwidth properly, the announcement including the value of the first bandwidth to the destination unit <NUM>.

Note that although in <FIG>, the repeater <NUM>-<NUM> is connected to the repeater <NUM>-N to simplify the figure, multiple repeaters may be connected between the repeater <NUM>-<NUM> and the repeater <NUM>-N.

The first bandwidth from the source unit <NUM> to the destination unit <NUM> is reserved in the communication path illustrated in <FIG> by transmitting the announcement including the value of the first bandwidth from the source unit <NUM> to the destination unit <NUM> as described above.

Description is provided below for the operation of the network monitor <NUM> configured as above.

<FIG> is a flowchart illustrating processes performed by the network monitor <NUM> according to the present embodiment. <FIG> illustrates processes from when the network monitor <NUM> receives an announcement of a first bandwidth from the source unit in the communication path until the network monitor <NUM> reserves the first bandwidth on the communication path.

First, at step S10, the receiver <NUM> receives an announcement from the source unit. More specifically, the receiver <NUM> receives the announcement transmitted by the source unit using a mechanism for bandwidth reservation and including the value of the first bandwidth for the source unit to perform first data communication.

Next, at step S11, the determiner <NUM> compares the value of the first bandwidth included in the announcement received by the receiver <NUM> with the white list which the database <NUM> holds. More specifically, the determiner <NUM> compares the value of the first bandwidth with the second bandwidth for the first data communication, specified in the white list which the database <NUM> holds.

Next, at step S12, the determiner <NUM> determines whether the first bandwidth is included in the second bandwidth specified in the white list. More specifically, the determiner <NUM> determines whether the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, for example, as illustrated in <FIG>.

Next, at step S12, if the first bandwidth is within the second bandwidth (YES at S13), the bandwidth reserver <NUM> reserves the first bandwidth on the communication path (S13). More specifically, if the determiner <NUM> determines that the value of the first bandwidth is included in the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the bandwidth reserver <NUM> reserves the first bandwidth.

Next, at step S14, the determiner <NUM> forwards the announcement to the next repeater. More specifically, since the determiner <NUM> determined at step S13 that the first bandwidth is to be reserved, the determiner <NUM> forwards the announcement including the value of the first bandwidth to the next repeater on the communication path.

Next, at step S15, the transmitter <NUM> transmits to the source unit the result of successful reservation indicating that the first bandwidth has been reserved.

On the other hand, if the first bandwidth is not within the range of the second bandwidth at step S12 (NO at S12), the bandwidth reserver <NUM> does not reserve the first bandwidth on the communication path (S16).

Next, at step S17, the transmitter <NUM> transmits to the source unit the result of reservation failure indicating that the first bandwidth has not been reserved.

As described above, the network monitor <NUM> of the present embodiment or the like compares the value of the first bandwidth required in the announcement from the source unit included in the communication path with the value of the second bandwidth specified in the white list which the database <NUM> holds. This operation makes it possible to determine whether the reservation of a bandwidth in the communication path of the in-vehicle network is inappropriate.

Since the network monitor <NUM> of the present embodiment or the like can determine whether the reservation of a bandwidth, which is a band necessary in the communication path of the in-vehicle network, is inappropriate, the network monitor <NUM> can discard an inappropriate bandwidth request that deviates from a predetermined communication range. This prevents a certain service from reserving an inappropriately large bandwidth, which, in turn, prevents the certain service from occupying the communication band inappropriately and causing a situation where other services cannot communicate.

Note that although the present disclosure has been described based on the above embodiment, it goes without saying that the present disclosure is not limited to the above embodiment. The following cases are also included in the present disclosure.

The operation may be such that even when the first bandwidth is out of the range of the second bandwidth, the network monitor <NUM> reserves the first bandwidth on the communication path temporarily and stores the determination result indicating that the first bandwidth is out of the range of the second bandwidth. This is because the passengers of the vehicle may be put in a dangerous situation unless the first bandwidth is reserved on the communication path temporarily, depending the operating state of the vehicle having the in-vehicle network including the ECU in which the network monitor <NUM> is included. Then, after analyzing the log, if it is found that the first bandwidth reserved temporarily is truly inappropriate, the first bandwidth can be, for example, discarded according to the operating state of the vehicle.

In other words, more specifically, the determination result of the determiner <NUM> may include the operating state of the vehicle <NUM> by the determiner <NUM> further determining the operating state of the vehicle <NUM> in the network monitor <NUM>. Then, even when the determiner <NUM> determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, the bandwidth reserver <NUM> may reserve the first bandwidth if the operating state of the vehicle <NUM> is a driving state. The determination result is stored as a log.

In addition, the white list which the database <NUM> holds may further include a response action item for each entry of the white list for switching action such as whether to reserve the first bandwidth on the communication path or not when the first bandwidth is out of the range of the second bandwidth. In this case, for a certain entry, the operation may be, for example, such that not reserving the first bandwidth on the communication path, the determination result is always stored in a log. Note that for this certain entry, the operation may be such that the determination result may always be store as a log when the first bandwidth on the communication path is not reserved. This operation makes it possible to reserve the first bandwidth temporarily and store the determination result as a log or, for example, to discard the first bandwidth, depending on the operating state of the vehicle.

In addition, in the above embodiment, if the first bandwidth is out of the range of the second bandwidth, the network monitor <NUM> transmits to the source unit the result of reservation failure indicating that the first bandwidth has not been reserved. However, it is not essential to transmit the result.

(<NUM>) In the above embodiment, the network monitor <NUM> may make the vehicle <NUM> slow down and then stop as an action when the first bandwidth is out of the range of the second bandwidth. Alternatively, the network monitor <NUM> may stop the automated driving and cancel the ADAS function as an action in this case.

More specifically, the determiner <NUM> may further determine the operating state of the vehicle <NUM>. In this case, the operation may be such that if the determiner <NUM> determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, and also the operating state of the vehicle <NUM> is a driving state, the network monitor <NUM> transmits to the vehicle an instruction to slow down and then stop the vehicle <NUM>. This makes it possible to change the operating state of the vehicle depending on the determination result whether the first bandwidth is inappropriate and thus to prevent an impediment to the automated driving or the like which may lead to a serious accident.

In addition, if the determiner <NUM> determines that the value of the first bandwidth is out of the range of the second bandwidth specified by the normal band value and the abnormality judgment value, and the vehicle <NUM> is in the operating state where the automated driving function or the driving assistance function is in operation, the network monitor <NUM> may transmit to the vehicle <NUM> an instruction to stop the automated driving function or the driving assistance function. This makes it possible to change the operating state of the vehicle depending on the determination result whether the first bandwidth is inappropriate and thus to prevent an impediment to the automated driving or the like which may lead to a serious accident.

(<NUM>) Although in the above embodiment, the network monitor <NUM> transmits to the source unit the determination result of comparison with the white list which the database <NUM> holds, the present disclosure is not limited to this operation. The network monitor <NUM> may transmit the determination result to the cloud server <NUM> or a server on a network outside the in-vehicle network. The network monitor <NUM> may transmit the determination result to the IVI (in-vehicle Infotainment). The network monitor <NUM> may transmit the determination result to another vehicle via V2X (vehicle-to-everything). The network monitor <NUM> may transmit the determination result to components of the infrastructure, such as traffic signals and road signs, via V2i (Vehicle-to-Infrastracture).

(<NUM>) In the above embodiment, the database <NUM> holds a predetermined white list. Parameters written in the white list, such as the normal band value and the abnormality judgment value that specify the second bandwidth, may be determined based on the specification of the data communication. In other words, the parameters may be determined based on the second bandwidth that is considered to be normal when a service performs data communication based on the specification of each service. The method of determining the parameters is not limited to the one based on the specification of the data communication described above but may be based on learning. In addition, the parameters may be updated, after determined once, by giving feedback of results of trial operation of each type of vehicle. A conceivable update frequency is once every two weeks, for example.

(<NUM>) Although in the above embodiment, the database <NUM> uses the normal band value and the abnormality judgment value as parameters to specify the second bandwidth in the white list, the present disclosure is not limited to these parameters. For example, as illustrated in <FIG>, the white list may include a list that defines the frequency per a certain time on a data communication type basis, or the white list may include the frequency per a certain time in the total which is the total number of times of data communication that passes through the communication path.

Here, <FIG> is a diagram illustrating another example of a white list which the database <NUM> according to the present disclosure holds. Also, in the example illustrated in <FIG>, the types of data communication used by the services are rear-camera video, a LIDAR signal, remote-control data, and "Total", which is the total number of times of data communication that passes through the communication path. For the rear-camera video, the maximum number of times is, for example, <NUM>/min. For the LIDAR signal, the maximum number of times is, for example, <NUM>/min. For the remote-control data, the maximum number of times is, for example, <NUM>/min. For the "Total", the maximum number of times is, for example, <NUM>/min. Note that since these values are examples, after using each service in a normal manner for a certain time, another value may be set from the increase/decrease in the amount of traffic during the certain time. Further, the user may set the maximum numbers of times to certain values.

This makes it possible to cope with an inappropriate request for reservation for a large first bandwidth even if the first bandwidth is within a normal range. Specifically, this make it possible to cope with a DDoS (distributed denial of service) attack which intentionally imposes an excessive load on the network resources.

(<NUM>) In the above embodiment, the type of data communication that the network monitor <NUM> handles using the database <NUM> may be stream IDs included in IEEE1722 frames, port numbers used in TCP/UDP, IP addresses, MAC addresses, or the like.

(<NUM>) The in-vehicle network may be CAN, CAN-FD, LIN, or Flexray, or may be a combination of any of these.

In the above embodiment, the present disclosure has been described as a cyber security measure for the in-vehicle network used in an automobile.

(<NUM>) Each device in the above embodiment is, specifically, a computer system including a microprocessor, ROM, RAM, hard disk unit, display unit, keyboard, mouse, and the like. The RAM or the hard disk unit stores a computer program. Each device achieves its function by the microprocessor operating according to the computer program. Here, the computer program includes combinations of multiple instruction codes which are instructions for the computer to achieve a predetermined function.

Claim 1:
A network monitor (<NUM>) for an in-vehicle network used in a vehicle,
the in-vehicle network being formed by multiple electronic control units including a source unit (<NUM>), a destination unit (<NUM>), and one or more repeaters (<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-N) that form a communication path in the in-vehicle network,
each of the one or more repeaters (<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-N) including an implementation of the network monitor (<NUM>),
the network monitor (<NUM>) comprising:
a receiver (<NUM>) that receives an announcement transmitted by the source unit (<NUM>) using a mechanism for bandwidth reservation, the announcement including a value of a first bandwidth for the source unit (<NUM>) to perform first data communication;
a database (<NUM>) that holds a white list in which a second bandwidth is specified on a data communication type basis, wherein
the white list includes parameters, on a data communication type basis, indicating a normal band value and an abnormality judgment value that specify the second bandwidth;
a determiner (<NUM>) that determines whether to reserve the first bandwidth by comparing the value of the first bandwidth with the second bandwidth for the first data communication specified in the white list, wherein
the determiner (<NUM>) compares the value of the first bandwidth with the parameters included in the white list and determines whether to reserve the first bandwidth depending on whether the value of the first bandwidth is included in a range of the second bandwidth specified by the normal band value and the abnormality judgment value;
a bandwidth reserver (<NUM>) that reserves the first bandwidth depending on a determination result of the determiner (<NUM>); and
a transmitter (<NUM>) that transmits the determination result of the determiner (<NUM>).