METHOD FOR RECORDING A TRAFFIC SITUATION IN A GEOGRAPHIC AREA BY TRANSMITTING A MESSAGE CONTENT, TELECOMMUNICATIONS NETWORK OR SYSTEM, ROAD PARTICIPANTS, COMPUTER PROGRAMME AND COMPUTER-READABLE MEDIUM

Description

State of the art

[0001] The invention relates to a method for detecting a traffic situation in a geographical area by transmitting a message content from a stationary transmitter to a stationary receiver via a plurality of mobile road users, wherein both the transmitter and the plurality of mobile road users are capable of sending broadcast messages with a message content and wherein the stationary receiver is capable of receiving broadcast messages, wherein the message content of at least one broadcast message from the transmitter is sent to at least one of the plurality of mobile road users by means of the at least one broadcast message using a PC5 sidelink functionality, in particular using the Mode 4 functionality.

[0002] The invention further relates to a telecommunications network or a system for detecting a traffic situation in a geographical area by transmitting a message content from a stationary transmitter to a stationary receiver via a plurality of mobile road users, wherein both the transmitter and the plurality of mobile road users are capable of sending broadcast messages with a message content, wherein the message content of at least one broadcast message of the transmitter is sent to at least one of the plurality of mobile road users by means of the at least one broadcast message using a PC5 sidelink functionality, in particular using the Mode 4 functionality.

[0003] The invention further relates to a road user for use in a telecommunications network according to the invention or in a system according to the invention.

[0004] Furthermore, the invention relates to a computer program comprising instructions with the aid of which the steps of a method according to the invention can be carried out, and to a computer-readable medium provided for storing a computer program, or a data carrier signal provided for transmitting a computer program, wherein the computer-readable medium or the data carrier signal stores or transmits the computer program according to the invention.

[0005] In existing telecommunications networks, the use of device-to-device communication is already known. This is also the case with cellular V2X communication (C-V2X), which enables communication participants or road users to exchange messages authentically or authorized, anonymously, and directly (i.e., without involving the mobile network, particularly via the PC5 sidelink functionality) in a confined environment, particularly for implementing key use cases such as road safety, traffic management, and infotainment.

[0006] When traffic flow information is known in advance and the basic information needed to be collected, problems need to be solved, such as the timeliness and accuracy of the data or results, as well as the costs of the process and the development of an infrastructure.

[0007] The document DE102011009812 discloses a method for transmitting at least one item of traffic information describing the current traffic status of a route section to an information receiver, wherein a first communication module of a communication device of a motor vehicle located on the route section transmits the traffic information to the information receiver via a targeted communication connection, wherein, in the case of several motor vehicles traveling on the route section with a communication device designed to transmit to the information receiver, the number of motor vehicles transmitting the traffic information to the information receiver is reduced by communication, in particular broadcast communication, of at least two motor vehicles on the route section by means of a second communication module of the communication device,and wherein, using a communication protocol, the communication determines a common traffic information item and a motor vehicle transmitting this traffic information to the information recipient, after which the specific motor vehicle transmits the specific common traffic information item to the information recipient, as well as a motor vehicle. Disclosure of the invention

[0008] The invention is based on the object of specifying a method for determining the traffic flow of vehicles (or road users) on a predefined road section as simply, quickly and with a high degree of timeliness and accuracy as possible, while keeping infrastructure costs and communication expenditure to a reasonable level, wherein the transmission of a message content of positions, speeds, as well as their times and information about the vehicle type and the maximum possible speed of the vehicle from the vehicles on the road section during a short period of time (for example in the single-digit second range) by means of a plurality of broadcast messages in order to record as many vehicles (or road users) as possible.road users) between the start and end point of the road section, wherein the (stationary) transmitter at the start point of the road section transmits at least one initial broadcast message, wherein the message content is sent by the transmitter to a plurality of receivers (road users) as a broadcast message by means of a D2D functionality, device-to-device functionality or a PC5 sidelink functionality, in particular using the Mode 4 functionality.

[0009] The object is achieved according to the invention by a method for detecting a traffic situation according to claim 1.

[0010] According to the present invention, it is therefore advantageously possible, in a comparatively simple manner, to effectively cover the predetermined road section (i.e. the message content is transmitted to the relevant recipients within the geographical area) and, secondly, to keep the number of messages used or required for this purpose comparatively small. However, a balance must be struck between the total number of broadcast messages to be sent on the one hand and the detection of as many vehicles as possible on the road section on the other, since the more messages that are sent, the more vehicles can be detected, which also depends on the total length of the road section, the transmission radii and the vehicle densities on the sub-sections.According to the invention, it is particularly possible to provide a mesh method for broadcast chain messages with mobile vehicle broadcast transmitters for notification on a defined road section with a defined direction of travel, largely minimizing the number of necessary broadcast messages, and to address as many of the vehicles on the road section that have the capability to participate in the method, and to retrieve the data they require and transport it to the final recipient. In particular, according to the invention, communication according to the PC5 Sidelink specification - as implemented for LTE - is suitable for this purpose. With regard to the goal of reaching or integrating as many vehicles as possible,For example, the target values ​​of mean average speeds for sub-sections or the entire section will be reduced by at least a single-digit percentage or even a higher double-digit percentage of vehicles; this follows from the fact that if, for example, approximately 50% of the vehicles that are sufficiently evenly distributed over the section move smoothly, for example within the range of the recommended speed, then the other 50% of the vehicles will also move accordingly.

[0011] According to the invention, it is thus provided that between the transmitter and the receiver, ie in the area of ​​the geographical area, several road users who act as communication participants each first receive a broadcast message with a specific message content (or several broadcast messages each with a specific message content) and then (at least as a rule) send another broadcast message with another message content, such that the receiver receives at least one broadcast message with a specific message content.

[0012] According to a preferred embodiment of the present invention, it is preferably provided that the geographical area corresponds to a section - in particular a route section, a traffic route, in particular a road, such as an expressway or motorway - or the geographical area defines the corresponding area of ​​the section of the traffic route, wherein in particular the area information comprises direction information and / or wherein the area information comprises position information of the stationary receiver.

[0013] As a result, according to such an embodiment of the invention, it is advantageously possible to carry out the method according to the invention simply and efficiently and to carry out a recording of the traffic situation in a geographical area.

[0014] According to the invention, it is provided that the position information of the current position of the road user under consideration is position information on the section of the traffic route and that the additional information comprises at least one of the following information: -- vehicle type information, -- vehicle category information, in particular whether it is a passenger car or a truck, further preferably whether it is a sports car or a saloon or a station wagon or a sports utility vehicle or a truck with a trailer, -- information on the maximum speed of the vehicle, -- information identifying the vehicle, in particular information identifying the vehicle pseudonymously.

[0015] As a result, according to such an embodiment of the invention, it is advantageously possible that only road users are included who are actually located on the considered section of the traffic route or it is advantageously possible that the additional information comprises vehicle type information and / or vehicle category information and / or information on the maximum speed of the vehicle and / or information identifying the vehicle, in particular pseudonymously identifying information, so that the detection of the traffic situation in the geographical area can be carried out efficiently and comparatively quickly.

[0016] According to a further embodiment of the present invention, it is preferably provided that the road user under consideration sends the at least one further broadcast message only if the current or last determined position of the road user under consideration is recognized by the position determining means of the road user under consideration as being within the geographical area or if the road user under consideration is recognized by the position determining means as being on the section of the traffic route and / or is recognized as moving on the section of the traffic route in the direction of or in accordance with the direction information.

[0017] As a result, according to such an embodiment of the invention, it is advantageously possible to carry out the method according to the invention particularly simply and efficiently.

[0018] According to a further embodiment of the present invention, it is preferably provided that the road user in question sends the at least one further broadcast message at the earliest after the expiry of a time interval after the reception of the at least one broadcast message in the first step, wherein the time interval corresponds to the aggregation time information or is defined as part of the aggregation time information, wherein in particular the at least one broadcast message received by the road user in question is -- a broadcast message sent by the stationary transmitter or -- a further broadcast message sent by another road user, wherein the method comprises, in particular as part of the second step: -- the road user in question receives additional broadcast messages from additional other road users within the time interval, wherein the additional broadcast messages, in addition to their respective message identification information, area information, repetition information and aggregation time information, have respective additional supplementary information, and -- the road user in question sends the at least one further broadcast message in such a way,that the at least one further broadcast message comprises as its message content the message content of the at least one broadcast message and as part of its supplementary information comprises the additional supplementary information of the additional broadcast messages received from the additional other road users within the time interval, wherein in particular the additional supplementary information is cleaned up in such a way that no road user is considered twice.

[0019] As a result, according to such an embodiment of the invention, it is advantageously possible to carry out the method according to the invention particularly simply and efficiently.

[0020] According to a further embodiment of the present invention, it is preferably provided that - in a third step and depending on the repetition information - the second step is repeated by the road user under consideration, wherein the road user under consideration sends a further broadcast message in repetition of the second step at the earliest after the expiration of a new time interval after the previous execution of the second step, wherein the new time interval corresponds to the aggregation time information or is defined as part of the aggregation time information, wherein the method comprises in particular as part of the third step: -- the road user in question receives additional broadcast messages from additional other road users within the renewed time interval, wherein the additional broadcast messages, in addition to their respective message identification information, area information, repetition information and aggregation time information, comprise respective additional supplementary information, and -- the road user in question sends the renewed broadcast message such that the renewed broadcast message comprises as its message content the message content of the at least one broadcast message and comprises as part of its supplementary information the additional supplementary information of the additional broadcast messages received from the additional other road users within the renewed time interval, in particular, the additional supplementary information is adjusted in such a way that no road user is taken into account twice, in particular the third step being carried out several times depending on the repetition information.

[0021] According to a further embodiment of the present invention, it is preferably provided that the road user in question uses the same supplementary information with regard to the further broadcast message and with regard to the at least one further broadcast message, in particular with regard to the position information, the speed information, the time stamp information and the additional information.

[0022] According to a further embodiment of the present invention, it is preferably provided that the message content of the at least one broadcast message comprises at least one of the following information: -- Traffic flow information relating to at least one further geographical area, in particular a section, in particular a route section, of a traffic route, in particular a road, which follows the geographical area in the direction of travel of the road users, -- Traffic flow information relating to a plurality of alternatively usable routes which follow the geographical area in the direction of travel of the road users.

[0023] Furthermore, the object is achieved by a telecommunications network or a system for detecting a traffic situation according to claim 9.

[0024] It is therefore advantageously possible according to the present invention to provide a telecommunications network or system according to the invention corresponding to the method according to the invention.

[0025] The object is further achieved by a road user, in particular with transmitter and receiver functionality, for use in a telecommunications network or system according to the invention.

[0026] Furthermore, the problem is solved by a computer program comprising instructions with the aid of which the steps of a method according to the invention can be carried out when the computer program is executed on a programmable device, in particular on a network node in the form of a transmitter and / or receiver and / or a communication participant.

[0027] Furthermore, the object is achieved by a computer-readable medium provided for storing a computer program, or data carrier signal provided for transmitting a computer program, wherein the computer-readable medium or the data carrier signal stores or transmits the computer program according to the invention or wherein the computer-readable medium or the data carrier signal stores or transmits the part of the computer program according to the invention to be executed on a programmable device, in particular on a network node in the form of a transmitter and / or receiver and / or a communication participant.

[0028] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the essential inventive concept. Short description of the drawings

[0029] Figure 1 shows a schematic situation of a plurality of road users (acting as communication participants) within a geographical area for transmitting a message content from a stationary transmitter to a stationary receiver via a plurality of mobile road users. Embodiments of the invention

[0030] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0031] The present invention will be described with reference to specific embodiments and with reference to specific drawings, but the invention is not limited thereto, but only by the claims. The described drawings are merely schematic and non-limiting. In the drawings, the size of some elements may be exaggerated and not drawn to scale for illustrative purposes.

[0032] When an indefinite or definite article is used when referring to a single noun, e.g. "ein", "eine", "der", "die", "das", this includes a plural of that noun unless explicitly stated otherwise.

[0033] Furthermore, the terms first, second, third, and the like are used in the specification and claims to distinguish between similar elements and not necessarily to describe a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein may function in a different order than that described or illustrated herein.

[0034] In Figure 1 is schematically shown a situation of a plurality of (usually mobile) road users 21, 22, 23, 24 (which act as communication users) within a geographical area 100 for transmitting a message content from a stationary transmitter 20 to a stationary receiver 25 via a plurality of mobile road users 21, 22, 23, 24. In Figure 1several road users are shown, although only a first road user 21, a second road user 22, a third road user 23 and a fourth road user 24 are designated by reference numerals. Here, both the transmitter 20 and the plurality of mobile road users 21, 22, 23, 24 are capable of sending broadcast messages with a message content. The stationary receiver 25 is in any case (at least) capable of receiving broadcast messages. The message content of at least one broadcast message from the transmitter 20 is sent according to the invention to at least one road user 21, 22, 23, 24 of the plurality of mobile road users 21, 22, 23, 24 by means of the at least one broadcast message using a PC5 sidelink functionality, in particular using the Mode 4 functionality.The direct reception of a broadcast message transmitted by the transmitter 20 (and thus the reception of its message content) by a road user 21, 22, 23, 24 (or a plurality of such road users 21, 22, 23, 24) requires that the road user or users 21, 22, 23, 24 are located within a transmission area 20' or radio coverage area 20' of the transmitter 20. The radio coverage area 20' can thus be defined as the spatial area (in . Figure 1for example around the transmitter 20) within which radio signals emitted or radiated by this communication participant (ie in this case by the transmitter 20), in particular comprising one or more broadcast messages, still have a signal strength or signal properties such that the other road users 21, 22, 23, 24 as communication participants can receive and process them, i.e. if necessary, process and / or decrypt them. The approximate radius of the (essentially circular) radio coverage area 20' is typically in the range between approximately 50 m and several hundred meters, for example 200 m, 300 m, 400 m or 500 m.

[0035] According to the invention, it is provided that - after the reception of a considered broadcast message (outgoing from the transmitter 20) by, for example, the first road user 21 (i.e. in his capacity as a communication user or as a user of the method sequence according to the invention) - this first road user 21 in turn acts as a transmitter and sends a further broadcast message (in particular by means of a PC5 sidelink functionality, in particular using the Mode 4 functionality), wherein a transmission radius (comparable to that of the transmitter 20) and a radio coverage area to be considered for the first road user 21 also exist or can be assumed, which, however, for the sake of simplicity, is Figure 1 is not specifically marked and named; the same applies to the other road users, in particular the second, third and fourth road users 22, 23, 24.

[0036] According to the invention, it is thus provided that between the transmitter 20 and the receiver 25, ie in the area of ​​the geographical area 100, several road users 21, 22, 23, 24, who act as communication participants, each first receive a broadcast message with a specific message content (or several broadcast messages each with a specific message content) and then (at least as a rule) send another broadcast message with another message content, such that at least one broadcast message with a specific message content is received by the receiver 25. This is in Figure 1 schematically represented by two arrows A, which are intended to indicate the sending of an initial broadcast message (ie quasi at time t = 0) from the transmitter 20 and its reception by two road users, including the first road user 21. By means of an arrow B in Figure 1indicated that the first road user 21 sends a first further broadcast message at a later time (t = dt), which is received by the second road user 22 (and possibly other road users if they are in the corresponding reception area). By means of an arrow C in Figure 1indicated that the second road user 22 sends out a second further broadcast message at a later point in time (t = 2*dt), which is received by the third road user 23 (and possibly other road users if they are in the corresponding reception area). Since, according to the invention, each of the further broadcast messages comprises at least parts of the initial message content, at least these parts of the initial message content ultimately reach the receiver 25 after a certain number of further such message reception and subsequent message transmission events, analogous to a message chain, wherein the propagation direction of at least parts of the initial message content (or the propagation direction of the messages) is provided according to the invention in particular such that it is selected opposite to the direction of travel 101 of the road users.

[0037] Thus, according to the present invention, the implementation of the method for detecting the traffic situation with regard to a (ultimately any) road user under consideration (along the chain of road users involved) requires the following steps: -- in a first step, the road user in question receives at least one broadcast message (i.e. for example the first road user 21 receives the initial broadcast message from the sender 20 or the second road user 22 receives the first further broadcast message from the first road user 21 and so on), wherein the message content of the at least one broadcast message comprises at least -- message identification information, -- area information for defining the geographical area 100 -- repetition information and -- aggregation time information, -- in a subsequent second step, the road user in question sends at least one further broadcast message (i.e. for example the first road user 21 sends the first further broadcast message orthe second road user 22 sends the second further broadcast message and so on), wherein the at least one further broadcast message comprises as its message content the message content of the received at least one broadcast message and at least one item of supplementary information, wherein the supplementary information comprises at least: -- position information of the current position of the road user in question, -- speed information of the road user in question -- current time stamp information and -- additional information. includes.

[0038] It is thus possible by the method according to the invention to transmit data for current traffic flows of road sections by means of a plurality of broadcast message chains (between the transmitter 20 and the receiver 25 via several road users 21, 22, 23, 24), wherein the invention particularly provides for the propagation direction of this message transmission (or broadcast chain messages) to be opposite to the permitted traffic direction (or opposite to the traffic flow direction, reference numeral 101 in Figure 1). Thus, the invention implements a method for determining the current traffic flows of road sections by means of a plurality of broadcast message chains. In particular, it is provided that the transmitter 20, as an authorized transmitter (e.g. at the radio mast of a network operator and at the starting point of the geographical area, for example a road section), periodically transmits an initial special broadcast message, wherein the message content is sent from the transmitter 20 to a plurality of recipients (road users 21, 22, 23, 24) as a broadcast message by means of a D2D functionality, device-to-device functionality or a PC5 sidelink functionality, in particular using the Mode 4 functionality. The message is, in particular, only received by vehicles (road users orReceiving devices) on the road section of the geographical area 100 (defined in the initial broadcast message) and with the specified direction of travel 101 are enriched by their own information (in particular position, speed, time stamp and vehicle type) and sent again as a broadcast message (which can also be enriched by future recipients), whereby there can be (and usually will be) several chains of broadcast messages which are received by the receiver 25 (or by the final recipient), e.g. a special receiving unit on the radio mast of a network operator, when the end point of the road section is reached and are then processed into current traffic flow information of the road section.

[0039] Each such chain of broadcast messages (which "run" over or through the geographical area 100 to the receiver 25) is thus triggered or started by an initial special broadcast message, wherein such initial special broadcast messages are repeated by the transmitter 20 according to the invention in particular periodically (for example every 100, 200, 300, 400, 500, 600, 700 or 800 seconds or also every 2, 3, 4, 5, 8, 10, 12, 15, 18, 20, 25 or 30 minutes) (in particular using a different, for example incremented, message identification information).

[0040] In addition to such repeated, in particular periodically or regularly periodically repeated, generation of message chains from the sender 20 to the receiver 25 in the geographical area 100, according to embodiment variants of the invention, it is also provided that—in a third step of the method and depending on the repetition information—the second step is repeated by the road user in question. In repeating the second step, the road user in question sends a further broadcast message at the earliest after the expiration of a new time interval following the previous execution of the second step. The new time interval corresponds in particular to the aggregation time information and / or is defined as part of the aggregation time information.In this case, the road user in question receives, in particular, additional broadcast messages from additional other road users within the renewed time interval, wherein the additional broadcast messages, in addition to their respective message identification information, area information, repetition information, and aggregation time information, contain respective additional supplementary information. The road user in question then sends the renewed further broadcast message in such a way that the renewed further broadcast message comprises, as its message content, the message content of the at least one broadcast message (received by the road user in question) and, as part of its supplementary information, comprises the additional supplementary information of the additional further broadcast messages received from the additional other road users within the renewed time interval.In particular, according to the invention, the additional supplementary information is adjusted in such a way that no road user is considered twice. The repetition information specifies or indicates, in particular, whether the third step is performed at all (i.e., the second step is repeated) and also whether the third step is also repeated (i.e., ultimately, the second step is performed more than twice).

[0041] In particular, the invention provides that the road user under consideration uses the same supplementary information with regard to the further broadcast message and with regard to the at least one further broadcast message, in particular with regard to the position information, the speed information, the time stamp information and the additional information. Applied to all road users, this means that within a chain of broadcast messages (i.e., triggered or initiated by a specific (or considered) initial broadcast message from the transmitter 20 and comprising a specific (or considered) message identification information), all road users 21, 22, 23, 24 do not make any changes to the transmitted speed information, time stamp information and additional information, even though, for example, the position of a road user will have changed after the expiration of the new time interval.

[0042] According to the invention, according to further embodiments, subsections of the road section (or the geographical area 100) can also be further differentiated, since all data records contained in the broadcast messages are provided with positions and timestamps. Each receiver or road user 21, 22, 23, 24 on the road section will then receive the traffic information of the vehicles between it and the initial transmitter 20 and can use it as the most current traffic information (T-Info) for their route up to the initial transmitter (i.e., up to the beginning of the road section or geographical area 100 under consideration).

[0043] The final receiver 25 uses the aggregated information to transmit it as a high-frequency broadcast to all road users, so that every passing vehicle receives the traffic information for the section ahead. The message also contains the timestamp of the last aggregated broadcast message, which provided additional information about the traffic situation on the road section or geographical area in question.

[0044] According to the invention, compared to previously known telecommunications networks in which device-to-device communication is already used and in which the problem of a very large or too large number of messages arises in particular when message contents are to be transmitted in the form of chain messages and if possible all (or a sufficient number depending on the application) communication units of a given coverage area are to make their specific contribution, it is advantageously possible to achieve a good balance between communication effort and the benefit to be achieved through communication, which is particularly achieved through the special rules in the process flow and the mutual dependencies of message transmissions per communication unit (or road user) and the number of aggregated communication units with their individual vehicle information (in particular position, speed, etc.).) to the destination point.

[0045] According to preferred embodiments, it is particularly provided according to the invention that the geographical area 100 corresponds to a section, in particular a route section, of a traffic route, in particular a road, such as an expressway or motorway, or the geographical area 100 defines the corresponding area of ​​the section of the traffic route, wherein in particular the area information comprises direction information 101 and / or wherein the area information comprises position information of the stationary receiver 25.

[0046] The position information of the current position of the road user under consideration is preferably position information on the route section of the traffic route, ie by means of this condition it is possible to limit the number of broadcast messages sent according to the method according to the invention to those cases in which the road user under consideration is regarded or recognised as being in the geographical area 100 (or on the route section under consideration).

[0047] According to the invention, the additional information comprises at least one of the following information: vehicle type information, vehicle category information, information on the maximum speed of the vehicle, information identifying the vehicle, in particular information identifying the vehicle pseudonymously.

[0048] Furthermore, the number of broadcast messages sent according to the method according to the invention can also be limited in that the road user in question only sends the at least one further broadcast message if the current or last determined position of the road user in question is recognized by the position determining means of the road user in question as being within the geographical area 100 or if the road user in question is recognized by the position determining means as being on the section of the traffic route and / or is recognized as moving on the section of the traffic route in the direction of or in accordance with the direction information 101.

[0049] According to the invention, it is provided that the road user in question sends the at least one further broadcast message at the earliest after the expiry of a time interval, dt, after the reception of the at least one broadcast message in the first step, wherein the time interval, dt, corresponds to the aggregation time information or is defined as part of the aggregation time information.

[0050] In particular, as part of the second step and within the time interval, the road user in question receives additional broadcast messages from additional other road users (see, for example, the dashed arrow pointing to the second road user 22 in Figure 1has), wherein the additional further broadcast messages, in addition to their respective message identification information, area information, repetition information and aggregation time information, have respective additional supplementary information, and (in particular also as part of the second step) the road user in question sends the at least one further broadcast message in such a way that the at least one further broadcast message comprises as its message content the message content of the at least one broadcast message and comprises as part of its supplementary information the additional supplementary information of the additional further broadcast messages received from the additional other road users within the time interval, wherein in particular the additional supplementary information is cleaned up in such a way that no road user is considered twice.

[0051] According to the invention, it is thus provided that the initial message transmitted by the transmitter 20 uniquely describes the road section 100 and the propagation direction of the message chains on the section. Each receiver that receives such a message and is located in the correct direction 101 on the section (moving or stationary, or in a lane 102 with the correct direction) will then check whether it needs to enrich this message, in particular with its current position, speed, timestamp, vehicle type, and maximum possible speed, i.e., with the supplementary information, and whether it should also immediately transmit this enriched message as a broadcast message. The rules for this check significantly reduce the number of broadcast messages according to the present invention.The vehicle will also check the merging of several broadcast messages received during a defined short period of time with its own data and then transmit the result as a broadcast message. This process of receiving, evaluating, enriching, and transmitting is carried out from vehicle to vehicle along the road section until the special receiving station 25 at the end of section 100 receives the enriched broadcast messages, including the last vehicle on the section. Thus, the basic data for determining the traffic flow on the entire road section and for subsections is available at the receiving station at the end of the section as soon as the chain messages have reached the receiving station in the appropriate wave.If all broadcast waves belonging to an initial message from the starting point fail to arrive at the final reception point, this means that there was a gap that was too large between neighboring vehicles en route, which usually means that communication is permanently interrupted for all waves triggered by this initial message. This is because such a gap will usually remain for all waves, as such a gap will not usually close sufficiently in the short period of time in which all the waves occur, as the vehicles are not moving fast enough (relative to each other). This is not usually critical, however, as the next initial broadcast message from the initial sender can, for example, be started periodically at intervals, whereby the time intervals are then not too short and can therefore be long enough to close gaps (particularly caused by relative movements of vehicles).Furthermore, the lack of arrival of such broadcast waves for a specific initial message can also be interpreted as indicating that there must be at least a large spatial gap between vehicles. If the total length of the road section was not chosen too long, this suggests relatively low traffic. Nevertheless, even a non-final message of a chain received by a vehicle on the road section contains basic data for the receiving vehicle to independently determine the traffic flow on its remaining route (remaining section) to the destination.

[0052] By including vehicle type information and maximum possible speed in the broadcast messages after the initial broadcast message, the goal of obtaining traffic flow information is significantly improved, as this allows data to be separated according to the vehicles' ability to move quickly. For example, a car driver with a fast sedan may not be able to make good use of traffic flow information provided by many trucks, as cars are generally driven differently than trucks. It is therefore preferable, for example, to exclude truck data from traffic flow information. Such separations are easily achieved using vehicle type information and maximum possible speed, for example by only using the relevant part of the base data.

[0053] According to the present invention, it is provided that a plurality of broadcast messages are used to transmit a message content. The message content is thereby to be distributed in a direction-oriented manner, counter to the direction of travel along a road section. A transmitter 20 transmits at least one initial broadcast message (with the initial message content) to a plurality of receivers as a broadcast message. This is achieved according to the invention using a D2D functionality, device-to-device functionality, or a PC5 sidelink functionality, in particular using the Mode 4 functionality. The transmitter has a radio coverage area within which reception of transmitted broadcast messages by receivers located there is possible.According to the invention, the road section should be covered as effectively as possible. For this purpose, in a first step, the sender sends the initial broadcast message comprising the message content and initial additional information, and a first receiver (or first road user 21) receives the initial broadcast message. In a subsequent second step, the respective receivers - as further transmitters - each send further broadcast messages, wherein the further broadcast messages comprise the message content and each further additional information on the traffic situation of the road section, namely their current own position on the road section, their current speed and the timestamp, as well as the vehicle type and maximum possible speed. This procedure ends with the receipt of the last chain messages within a defined boundary point of the road section.The position of the final receiver 25 should be as close as possible to the boundary point of the road section.

[0054] According to the invention, it is particularly preferably provided that the reception sensitivity of the final receiver 25 is as high as possible, in particular also higher than that of the vehicles or road users 21, 22, 23, 24. The same also applies to the transmission strength of the transmitter 20 of the initial message. Furthermore, it can preferably also be provided that a current vehicle in critical proximity (e.g. 500 m but its current transmission strength is only 400 m) of the final receiver 25 deliberately increases its transmission strength (here to >500 m) in order to bypass a potentially excessively large vehicle gap in front of the final receiver 25 and to reach the final receiver 25 directly and not via vehicles potentially traveling behind it.

[0055] The method according to the invention thus achieves that the message content for the road section is distributed via broadcast messages. To implement the broadcast method, for example, the PC5 broadcast communication specified in mobile networks according to 3GPP can be used. A mobile network (more precisely its base stations or antenna locations) is not necessarily required according to the invention. This means that the method according to the invention can also be used outside of terrestrial locations or outside the range of mobile networks. The V2V PC5 specification (vehicle-to-vehicle communication) is or will be specified for LTE or 5G, in particular to enable communication between end devices with the aid of a transmission tower; however, according to the invention, only the PC5 sidelink functionality for end device-to-end device communication without the support of a transmission tower is used.

[0056] The direct V2V communication via the PC5 interface (Mode 4 without using the mobile network) enables the very fast transmission of messages, which is very important for many applications, e.g. hazard warnings.

[0057] According to the embodiment of the present invention, it is provided that the initial additional information comprises at least -- a message identification information (unique incremented initial message ID, which together with the definition of the road section results in a unique overall ID and is not interchangeable)), -- a unique, unmistakable definition of the road section including the direction of travel and includes, whereby the additional information may also include any of the following information: -- the position information of the final receiver at the end of the road section (this can be used to increase the transmission power at this end of the road section to provide a higher guarantee that the chain messages will reach this specific receiver), -- the repetition information.

[0058] According to one embodiment of the present invention, the vehicle-specific additional information of a vehicle includes the following information: -- its two-dimensional position (and possibly also its three-dimensional position) on the road section contained in the initial message, i.e., the geographical area 100. The position may also be slightly off-road due to GNSS errors; however, this is usually corrected by the navigation system, as it is assumed that the road user in question is on the road section in question, by matching its position to the road. Alternatively, the position corrected by the navigation system could be converted into a GNSS position, and this would be used as the parameter value; however, the vehicle will only send its vehicle-specific additional information in a broadcast message if the navigation system (or a radio beacon) has decided that it is on the road section), -- its speed, -- the current time stamp, -- the vehicle type (e.g.Car or truck or even some further differentiation such as car-sports car or slow truck with trailer).

[0059] The vehicle-specific additional information may also include the following information: the maximum possible speed.

[0060] The road user in question (or recipient of the broadcast message) decides: -- based on its own current position, speed and direction check, whether the message content of the received broadcast message should be enriched with additional information and / or -- based on its current route, whether it should be evaluated as traffic flow information, wherein at least some of the receivers send further broadcast messages, provided that this has been determined by an algorithm for evaluating all broadcast messages already received by it and all broadcast messages already sent by it for this road section (and this initial message ID) and time thresholds.

[0061] The following describes how the number of broadcast messages sent can be minimized according to the invention while still achieving the goal of detecting a sufficient percentage of vehicles participating in the process (i.e., participating with regard to broadcast communication, localization in a road map system, 2D position, optional distance progress on the road section, current speed and direction of travel, timestamp) on the road section within a very short period of time after the initial message is sent with its basic traffic information. The inventive rules regarding the sending of a broadcast message to be enriched are specifically specified as follows: -- Rule 1: Within a specific time period dt (dt, for example, set to dt = 1 second by default configuration) or aggregation time information, a vehicle may only transmit one broadcast message containing enrichments of its position information, speed information, current timestamp information, and additional information. -- Rule 2: A vehicle may only transmit a maximum of a fixed number of broadcast messages (repetition information) for an initial message ID per default configuration value. In particular, this number must be sufficiently high if the number of vehicles on the entire section is to be determined as accurately as possible as an absolute value. The repetition information parameter can also be made dependent on the vehicle density. -- Rule 3: A vehicle may not perform any enrichment for an old initial message ID and may not transmit a broadcast message for it if it detects,that there is a newer initial message ID, which is possible through the receipt of a corresponding message or due to a known time advance for periodic transmission or a known other time scheme for repeating initial messages, -- Rule 4: after receiving a message, a vehicle must always wait a fixed time, dt, or aggregation time information, before sending an enriched broadcast message, -- Rule 5: as soon as a vehicle has decoded the first broadcast message with a new initial message ID, its data record (position, speed, timestamp) is collected and stored in the vehicle as a static triplet data record, -- Rule 6: a vehicle always saves the last broadcast message it sent and then deletes the previously saved sent message,-- Rule 7: a vehicle will enrich a newly received broadcast message with its own data (position, speed, timestamp) as well as the other parameters and enrich it with basic information not yet contained in its last broadcast message sent in an additional block and also use all new broadcast messages received within dt to enrich its broadcast message to be sent, whereby redundancy is avoided in all steps and this is possible by comparing all position-speed and timestamp data, since all data records of a broadcast message to be sent may only contain different triplets, otherwise too many vehicles would be counted and thus the weighting of the corresponding identical speeds in the later evaluation step would be too high,-- Rule 8: Before enriching, a vehicle must check its own data (in particular, position, speed, time stamp) to determine whether it is driving slowly on the hard shoulder or in a parking bay or is stationary, and whether this is not due to the traffic situation around the vehicle (however, if this cannot be determined clearly and unambiguously, these corrupting data can be detected later with more knowledge of the traffic situation in the immediate vicinity and sorted out as outliers that do not represent the general traffic flow). Thus, such a vehicle can receive and thin out several different messages, but when sending the enriched message, perform the enrichment without its own data triplet data set (it will therefore still be used as a special "relay" station to be able to close a 400m gap).

[0062] According to the invention, it is preferably provided that, due to the type of data in the broadcast messages, it cannot be inferred to an individual vehicle. This is because, although its position is transmitted at a given time, no connection can be established between any two of its positions (since each of its positions will be present in a message with a different initial message ID). Thus, no string of positions (positions of a lane) can be reconstructed for one and the same vehicle. Since no unique identity is revealed via the broadcast messages, the anonymity of each individual vehicle and its triplet information is guaranteed. The respective additional information (after the triplet) is not sufficiently differentiated to be able to establish clear connections.The only situation in which connections could be established between data with different initial message IDs arises when multiple initial messages are sent at an extremely high frequency, so that longer partial traces can be clearly reconstructed from positions and speeds. However, this can be clearly avoided by changing the frequency (e.g., intervals >2 minutes) of the initial messages (from transmitter 20) without limiting the advantages of the invention. Furthermore, the number of broadcast messages per day should be reduced as much as possible. The requirement of anonymity does not contradict the fact that the additional information may include information that identifies the respective vehicle, in particular that identifies the vehicle pseudonymously; such pseudonymous identification could advantageously be used to avoid double counting of vehicles.According to the invention, the at least one broadcast message of the transmitter 20 has the said parameters of the repetition information and the aggregation time information.

[0063] The method according to the invention also advantageously makes it possible to determine the number of vehicles on the road section under consideration during the passage of an initial broadcast message to the final receiver 25 at the end of the road section. The method according to the invention can therefore also be used to count the different vehicles passing through a specific road section.

[0064] If the additional information according to a considered embodiment of the invention comprises vehicle type information and information on the maximum speed of the vehicle, the counts differentiated according to these two additional parameters can be used to determine, for example, the mean average speeds for different vehicle types (car vs. truck; fast car vs. slow car). This, with regard to fast cars, says something about the free use of the overtaking lane or the discipline of slower vehicles to stay on the right for as long as possible. Other information, such as the general compliance with maximum permitted speeds, e.g. for sections with steep downward gradients, could also be derived for heavy trucks from the average speed on sections for a group of these trucks.

[0065] In order to avoid excessively large gaps (e.g., larger than transmission radius r=400m) between transmitters and the nearest receiver, a road section in the initial broadcast message should not be too long, ie the initial transmitting stations (the respective transmitters 20) and correspondingly also the final receiving stations 25 should be selected closer together along a road layout.

[0066] According to the invention, it is further preferably provided that the message content of the at least one broadcast message (ie the initial broadcast message of the transmitter 20) comprises at least one of the following information: -- Traffic flow information relating to at least one further geographical area, in particular a section, in particular a route section, of a traffic route, in particular a road, which follows the geographical area 100 in the direction of travel of the road users, -- Traffic flow information relating to a plurality of alternatively usable routes which follow the geographical area 100 in the direction of travel of the road users.Thus, according to the invention, it is advantageously possible for V2X traffic flow data to be transmitted and utilized via broadcast message chains in branched road systems, so that the following disadvantages can be avoided: Traffic information systems for a branched road network are cost-intensive, only partially provided with the most up-to-date traffic information (V-Infos), the V-Infos are not available seamlessly for all sections of a route, and use special communication systems based on special infrastructure.

[0067] It is thereby advantageously possible according to the invention for a road user (hereinafter also referred to as FZG) in a road network system (e.g. here always referred to as a federal motorway system, BAB system) to be provided with the most up-to-date traffic information (V-Info) on his possible routes on the road network system, without infrastructure-dependent communication systems such as a cellular mobile radio system being used and without a communication address of the FZG having to be known (i.e. strict compliance with data protection regulations (in particular privacy) is provided for).

[0068] This V-Info can, for example, be basic data collected / measured from other road users.

[0069] The vehicle requiring V-Info only needs to be able to receive broadcast messages containing V-Info data, and it must be able to determine at least the road currently being traveled on, its own position, and the direction of travel on the road in order to identify the data relevant to the vehicle from the V-Info data. This allows the vehicle to use V-Info data.

[0070] In order for the vehicle with V-Info requirements to also be able to serve other vehicles on the motorway when receiving such V-Info messages, the vehicle must also be able to send broadcast messages. To do this, it must be able to enrich the previously received message (or messages) with its own V-Info data and forward it as a broadcast message. To do this, it must also be able to determine its own basic V-Info data, such as its own speed and time.

[0071] Since the vehicle is located within a road network, it is interested in a traffic information system that covers as many different future junctions as possible. The vehicle is interested in the most up-to-date traffic information regarding its direction of travel, its currently used route, and even possible alternative routes. To enable this, we needed to define the basic traffic information data for a section and the basic mechanisms, including collecting, storing, and enriching traffic information data, which are described in "Invention Report_V2X Traffic Flow Data - Broadcast Message Chains Against the Direction of Traffic."

[0072] To choose the correct route on a motorway, the vehicle operator needs to know the current traffic situation at each motorway intersection (exit, Y-junction, motorway interchange). The closer the intersection is on its current route to its destination, the more urgent it is to receive this information about the traffic situation as up-to-date as possible.

[0073] Current traffic information systems cannot provide this high level of timeliness.

[0074] According to the invention, it is advantageously possible, in particular, to provide this traffic information of a road network with a timeliness, depending on the setup, in the range of seconds to minutes. Furthermore, the traffic information system will only provide the vehicle with the traffic information data for its current direction of travel and its possible junctions, thus minimizing data transfer.

[0075] The FZG will receive all V-Info information for its direction of travel for the next possible junctions (including sections without junctions) on a highway. From each junction, the future possible road sections and their further junctions, along with their section-specific V-Info data, will also be included in the "road network" V-Info broadcast message received by the FZG (with V-Info request). Based on this received "road network" V-Info broadcast message, the FZG can then decide which route to take (maintain the current route, choose a new route, or select the first route from an initial route request). The router that makes this decision can be located on-board the FZG, thus eliminating communications with off-board routers.

[0076] The V-Info broadcast message received in the FZG on the BAB road network will therefore contain all V-Info information for the sections of the BAB for the routes on the BAB network.

Claims

1. Method for detecting a traffic situation in a geographical region (100) by conveying a message content from a stationary transmitter (20) to a stationary receiver (25) via a transmission chain formed by a plurality of mobile traffic participants (21, 22, 22, 23, 24), both the transmitter (20) and the plurality of mobile traffic participants (21, 22, 23, 24) being capable of transmitting broadcast message comprising a message content, and the stationary receiver (25) being capable of receiving broadcast messages, the message content of at least one broadcast message of the transmitter (20) being transmitted to at least one of the plurality of mobile traffic participants (21, 22, 23, 24) by means of the at least one broadcast message by means of a PC5 sidelink functionality, in particular using mode 4 functionality, wherein the method for detecting the traffic situation comprises, for each relevant traffic participant of the transmission chain formed by the plurality of mobile traffic participants (21, 22, 23, 24), the following steps: - in a first step, the relevant traffic participant receives at least one broadcast message, the message content of the at least one broadcast message comprising at least - message identification information, - region information for defining the geographical region (100), - repetition information, and - aggregation time information, - in a following second step, the relevant traffic participant transmits at least one further broadcast message, the at least one further broadcast message comprising, as its message content, the message content of the received at least one broadcast message and at least one supplementary piece of information, the supplementary information comprising at least: - position information for the current position of the relevant traffic participant, - speed information for the relevant traffic participant, - current timestamp information, and - additional information, the additional information comprising at least one of the following pieces of information: - vehicle type information, - vehicle category information, - information on the maximum speed of the vehicle, - information identifying the vehicle, the relevant traffic participant transmitting the at least one further broadcast message, at the earliest, after the expiration of a time interval after the at least one broadcast message is received in the first step, the time interval corresponding to the aggregation time information or being defined as part of the aggregation time information, the repetition information specifying whether the second step is repeated.

2. Method according to claim 1, characterised in that the geographical region (100) corresponds to a portion, in particular a route segment, of a traffic route, in particular of a street such as a motorway or highway, or the geographical region (100) defines the corresponding region of the portion of the traffic route, in particular the region information comprising direction information (101) and / or the region information comprising position information of the stationary receiver (25).

3. Method according to either of the preceding claims, characterised in that the position information for the current position of the relevant traffic participant is position information on the route segment of the traffic route.

4. Method according to any of the preceding claims, characterised in that the relevant traffic participant transmits the at least one further broadcast message only when the current or most recently determined position of the relevant traffic participant is detected by position determination means of the relevant traffic participant as being within the geographical region (100) or when the relevant traffic participant is detected by the position determination means as being located on the portion of the traffic route and / or as moving along on the portion of the traffic route in direction or in accordance with the direction information.

5. Method according to any of the preceding claims, characterised in that the at least one broadcast message received by the relevant traffic participant - is a broadcast message transmitted by the stationary transmitter (20) or - is a further broadcast message transmitted by another traffic participant, the method in particular including, as part of the second step: - the relevant traffic participant receiving, within the time interval, additional further broadcast messages from additional other traffic participants, the additional further broadcast messages comprising associated additional supplementary information, as well as their associated message identification information, region information, repetition information and aggregation time information, and - the relevant traffic participant transmitting the at least one further broadcast message in such a way that the at least one further broadcast message comprises, as its message content, the message content of the at least one broadcast message and comprises, as part of its supplementary information, the additional supplementary information of the additional further broadcast messages received from the additional other traffic participants within the time interval.

6. Method according to any of the preceding claims, characterised in that, in a third step and as a function of the repetition information, the second step is repeated by the relevant traffic participant, the relevant traffic participant, in repeating the second step, transmitting a fresh further broadcast message, at the earliest, after the expiration of a fresh time interval after the previous performance of the second step, the fresh time interval corresponding to the aggregation time information or being defined as part of the aggregation time information, the method including, in particular as part of the third step: - the relevant traffic participant receiving, within the fresh time interval, additional further broadcast messages from additional other traffic participants, the additional further broadcast messages comprising associated additional supplementary information, as well as their associated message identification information, region information, repetition information and aggregation time information, and - the relevant traffic participant transmitting the fresh further broadcast message in such a way that the fresh further broadcast message comprises, as its message content, the message content of the at least one broadcast message and comprises, as part of its supplementary information, the additional supplementary information of the additional further broadcast messages received from the additional other traffic participants within the time interval, in particular the third step being performed repeatedly as a function of the repetition information.

7. Method according to the preceding claims, characterised in that the relevant traffic participant uses the same supplementary information for the further broadcast message and for the at least one fresh further broadcast message, in particular as regards the position information, the speed information, the timestamp information and the additional information.

8. Method according to any of the preceding claims, characterised in that the message content of the at least one broadcast message comprises at least one of the following pieces of information: - traffic flow information relating to at least one further geographical region, in particular to a portion, in particular a route segment, of a traffic route, in particular of a street, which follows on from the geographic region (100) in the direction of travel of the traffic participant, - traffic flow information relating to a plurality of alternatively useable routes which follow on from the geographical region (100) in the direction of travel of the traffic participant.

9. System for detecting a traffic situation in a geographical region (100) by conveying a message content from a stationary transmitter (20) to a stationary receiver (25) via a transmission chain formed by a plurality of mobile traffic participants (21, 22, 22, 23, 24), the system comprising the stationary transmitter (20), the stationary receiver (25) and the plurality of mobile traffic participants (21, 22, 23, 24), both the transmitter (20) and the plurality of mobile traffic participants (21, 22, 23, 24) being capable of transmitting broadcast message comprising a message content, the message content of at least one broadcast message of the transmitter (20) being transmitted to at least one of the plurality of mobile traffic participants (21, 22, 23, 24) by means of the at least one broadcast message by means of a PC5 sidelink functionality, in particular using mode 4 functionality, wherein each relevant traffic participant of the transmission chain formed by the plurality of mobile traffic participants (21, 22, 23, 24) is configured in such a way that: - the relevant traffic participant receives at least one broadcast message, the message content of the at least one broadcast message comprising - message identification information, - region information for defining the geographical region (100), - repetition information, and - aggregation time information, - the relevant traffic participant transmits at least one further broadcast message, the at least one further broadcast message comprising, as its message content, the message content of the received at least one broadcast message and at least one supplementary piece of information, the supplementary information comprising at least: - position information for the current position of the relevant traffic participant, - speed information for the relevant traffic participant, - current timestamp information, and - additional information, the additional information comprising at least one of the following pieces of information: - vehicle type information, - vehicle category information, - information on the maximum speed of the vehicle, - information identifying the vehicle, the relevant traffic participant being configured to transmit the at least one further broadcast message, at the earliest, after the expiration of a time interval after the at least one broadcast message is received in the first step, the time interval corresponding to the aggregation time information or being defined as part of the aggregation time information, the repetition information specifying whether the second step is repeated.

10. Traffic participant for use in a system according to claim 9.

11. Computer program comprising commands by way of which the steps of a method according to any of claims 1 to 8 can be carried out when the computer program is run on a programmable device, in particular on a network node in the form of a stationary transmitter (20) and / or stationary receiver (25) and / or mobile traffic participant (20, 21, 22, 23, 24).

12. Computer-readable medium provided for storing a computer program or data carrier signal provided for transmitting a computer program, the computer-readable medium or data carrier signal storing or transmitting the computer program according to claim 11, or the computer-readable medium or data carrier signal storing or transmitting the part of the computer program according to claim 11 which is to be carried out on the programmable device, in particular on a network node in the form of a stationary transmitter (20) and / or stationary receiver (25) and / or mobile traffic participant (20, 21, 22, 23, 24).