EP3534348B1 - Method and system for transferring road sign information via a cellular mobile radio network - Google Patents

Description

The present invention relates to a method and a system for transmitting traffic sign information to at least one road user currently affected by the traffic sign information, in particular to at least one vehicle, via a cellular mobile radio network.

Currently, a status of permanent traffic signs such as B. Speed limits, stored in map material for navigation systems for vehicles. However, today there is no efficient way of making dynamic changes to traffic sign systems, such as changing speed limits, changing overtaking bans, traffic lights, etc. available to a road user, in particular a driver of a vehicle.

Today, modern vehicles are often equipped with cameras to capture traffic signs and dynamically display them in an in-vehicle navigation system or a vehicle dashboard. However, such optical systems have the distinct disadvantage that a state of dynamic, i.e. H. a traffic sign that changes over time must first be recorded. On the one hand, optical systems are subject to limitations in a range that can be recorded by the systems; on the other hand, environmental conditions such as rain, fog or smoke etc. influence the quality of the recordings of the optical systems.

So-called Vehicle-2-Vehicle (V2V) and Vehicle-2-Infrastructure (V2I) systems are currently under development. Such systems are about to be ready for series production. In particular, the Vehicle-2-Infrastructure systems were developed so that traffic signs, ie "Infrastructure", can make a current status available to other road users, in particular vehicles, ie "Vehicle" via a radio protocol. The radio range is limited to 500 to 1000 m. In addition to such direct dissemination of status information from traffic signs or traffic sign systems, systems are currently being developed which transmit the status of the respective traffic signs permanently or regularly to a so-called back-end server. This back-end server, which is typically operated by a respective car manufacturer, then makes this data transmitted to it on status information of traffic signs available to a car fleet assigned to the back-end server via a normal mobile radio connection.

From the WO 2017/026992 A1 a method is known according to which a network node provides a first carrier for a user device for sending an uplink communication to an application server. The user device is configured for vehicle-to-vehicle or vehicle-to-infrastructure communication. The method described can also include setting up a second carrier for the application server to send downlink communications to the user equipment. Furthermore, the method can also include sending uplink and downlink communications between the user device and the application server.

Due to the respective transmission of respective status information from traffic signs to each individual vehicle, the status information of the respective traffic signs is limited to only a certain part of vehicles, which in turn means that utilization of the valuable radio resources used is not particularly high or efficient.

In the US 2016/258777 A1 describes user equipment (UE) that provides driving assistance based on road infrastructure information. The UE may have a wireless interface that communicates over a wireless channel, a positioning system configured to determine a location of the UE, memory configured to store instructions, and a processor configured to execute the instructions stored in memory is to include.

Accordingly, it was an object of the present invention to provide a way of making dynamic changes to traffic signs or traffic sign systems available to road users in the most efficient way possible.

To solve this problem, a method, a system and a mobile radio terminal with the features of the independent patent claims are presented. Refinements of the method, the system and the mobile radio terminal emerge from the dependent claims and the description.

According to the invention, a method for transmitting traffic sign information to at least one road user currently affected by the traffic sign information, in particular to a vehicle, via a cellular mobile radio network is presented. In the method according to the invention, the traffic sign information is transmitted from at least one traffic sign system to a central server, the transmitted traffic sign information is linked to a location of the at least one traffic sign system and together with the location information of the at least one traffic sign system from the central server within at least one cell of the mobile network by means of at least one broadcast - or multicast message, the at least one cell within which the broadcast or multicast message is broadcast is the cell in which the at least one road user is at the time of the broadcast, the traffic sign information regarding a respective change frequency, with which the traffic sign information each time change, differentiate, evaluate and be classified in a ranking order relative to one another and are respectively transmitted according to this ranking with a transmission frequency assigned to a respective ranking position.

According to the invention, it is therefore proposed to transmit or broadcast traffic sign information within a restricted geographical area.

In one possible embodiment, before the traffic sign information is broadcast, it is calculated in which at least one cell the at least one road user currently affected by the traffic sign information will be at the time the at least one broadcast / multicast message is broadcast. Furthermore, this at least one cell is called defines the at least one cell within which the at least one broadcast / multicast message is broadcast. As a rule, the at least one broadcast / multicast message is broadcast at least in the cell in which the at least one traffic sign system is located.

As a rule, the traffic sign information is transmitted from several or a plurality of traffic sign systems to the central server. This means that, as a rule, respective traffic sign systems transmit respective traffic sign information pertaining to them or emanating from / encompassing them to the central server. The respective traffic sign information of a respective traffic sign system is linked to a respective location of a respective traffic sign system of the plurality of traffic sign systems and is broadcast together with respective location information of the respective traffic sign system from the central server within at least one respective cell of the mobile network using the at least one broadcast / multicast message. It is conceivable that for each traffic sign system whose traffic sign information is to be broadcast, a broadcast / multicast message is generated and broadcast in at least one cell, in particular at least in the cell of the mobile network in which the respective traffic sign system is located. In order to increase the efficiency of the system, it is proposed according to the invention that the traffic sign information from several traffic sign systems be combined in a single broadcast / multicast message and together as a broadcast / multicast message in the at least one cell of the mobile network, in particular in the cell , in which the several traffic sign systems are located together, are broadcast. Accordingly, in advance of generating the broadcast / multicast message, the location information of the multiple traffic sign systems providing the traffic sign information is evaluated to determine which traffic sign systems are located together in a cell, so that their respective traffic sign information to be broadcast is combined can be broadcast in a common broadcast / multicast message.

It must be taken into account that the central server evaluates those cells of the mobile network in which the broadcast / multicast message and thus the traffic sign information from a respective traffic sign system or from the multiple traffic sign systems are to be broadcast in advance of the broadcast. The broadcast / multicast message should mainly be used to address those road users who are currently affected by the respective traffic sign information of the respective traffic sign systems or at least part of the traffic sign information of the traffic sign systems when the broadcast / multicast message is broadcast, i.e. H. which are located in the vicinity of the respective location of the respective traffic sign systems and are also aligned relative to at least one of the traffic sign systems and / or move relative to at least one of the traffic sign systems that they are directly affected by the traffic sign information of the respective traffic sign system, d. H. must take this traffic sign information into account when continuing your journey.

In general, a broadcast message reaches all road users who, at the time of transmission of the broadcast message, are within the cell within which the broadcast message is transmitted locally. It is in the nature of the broadcast message that none of the recipients or road users or a mobile radio terminal included by the receiver or road user is explicitly specified, but in principle broadcast by all road users or mobile radio terminals included by them that are configured for this purpose -To receive messages, and which are located at the time within the cell of the transmission of the broadcast message can be received. As an alternative to this, the traffic sign information can also be broadcast in the form of a multicast message, with the road users or those from being used to receive the multicast message this encompassed mobile radio terminals must first register with the central server. It is conceivable that the road users or the mobile radio terminals included by them generally register to receive such multicast messages in order to use this service.

Due to specific information within the broadcast / multicast message with regard to an alignment of the traffic sign system relative to the course of the road and / or an indication of vehicles or vehicle types that are affected by the traffic sign information, it is conceivable that a kind of preselection of the To make traffic sign information currently affected road users, filtering based on this information ultimately usually takes place at the respective road user or the mobile radio terminal included by the respective road user itself. It is conceivable that a respective road user has implemented a filter unit in a mobile radio terminal or receiving module configured to receive broadcast / multicast messages which, on the basis of the aforementioned information within a respective broadcast / multicast message, makes a preselection with regard to the specific Road user can make and therefore only those broadcast / multicast messages are processed and possibly displayed within the vehicle that are actually relevant for the respective vehicle of the respective road user. It is also conceivable that only the traffic sign information of the broadcast / multicast message that relates to the respective road user is displayed by filtering. In addition, there is generally the possibility that a road user can activate and also deactivate a receiving module or mobile radio terminal included by him for the reception of broadcast / multicast messages, with a deactivation of the receiving module or the mobile radio terminal for receiving broadcast / multicast messages. Multicast messages do not receive any broadcast / multicast messages that are broadcast within the cell in which the road user is currently located.

It is conceivable that the respective broadcast / multicast message is only broadcast within that cell of the mobile network in which the traffic sign system or the traffic sign systems themselves are located, which can be evaluated relatively easily depending on the determined respective location of the traffic sign systems can. Furthermore, however, it is also conceivable that the traffic sign information of a respective traffic sign system or of several traffic sign systems is also transmitted in one or more cells adjacent to the cell in which the respective traffic sign system or the several traffic sign systems are located, because the speeds driven by the respective road users, not all road users who are or will be affected by the traffic sign information of the respective traffic sign systems are already in the immediate vicinity of the respective traffic sign systems when the broadcast / multicast message is broadcast, but are approaching them in such a way, that knowledge of the traffic sign information at the time of broadcasting the broadcast / multicast message is also of high relevance for these road users so that they are not informed about it too late.

With the aid of the at least one broadcast / multicast message relating to the respective traffic sign information of a respective traffic sign system, the respective traffic sign information can be transmitted simultaneously to a plurality of road users currently affected by the traffic sign information. This means that there is no separate transmission from the central server to an individual vehicle or road user, but rather a message is sent out in the form of a broadcast / multicast message within a respective cell of the cellular mobile network and thus everyone is in it Road users located in the cell who are configured to receive messages via the cellular mobile network, can receive this broadcast / multicast message and can therefore view the respective traffic sign information of the respective traffic sign system. This allows resources saved and traffic sign information can be transmitted efficiently. For this, however, the road users must have mobile radio terminals or terminals which are designed to be able to receive broadcast / multicast messages from the central server or to activate such a service or service for receiving broadcast / multicast messages. Furthermore, the road users must be in the cell in which the broadcast / multicast message is sent out. It is conceivable that a respective road user, in particular a vehicle, sees such broadcast / multicast messages either on demand, ie first has to be active in order to be able to view messages that have arrived, or as so-called automatic displays, for example in the form of a Running text in a standby display of the respective vehicle recognizes.

The cellular mobile network can be a 2G (second generation) public mobile network, such as a GSM network with GERAN (GSM EDGE Access Network) network, or a 3G (third generation) public mobile network, such as a UMTS network UTRAN (UMTS Terrestrial Radio Access Network) network, a 4G (fourth generation) public cellular network such as an LTE network or a 5G (fifth generation) public cellular network such as an NR network.

In a possible embodiment, a network built and operating on the basis of the LTE (Long Term Evolution) standard or the NR (3GPP New Radio) standard is selected as the cellular mobile radio network. In the context of the present disclosure, a network set up and operating in accordance with the LTE standard is referred to as an LTE network and a network built and operating in accordance with the NR standard is referred to as an NR network.

In a further embodiment, it is conceivable that the traffic sign information is broadcast by means of eMBMS or SC-PTM using an eMBMS protocol. eMBMS (evolved Multimedia Brodcast Multicast Service) is a mobile network extension, ie broadcasting over LTE in order to be able to distribute content to many users at the same time. Part of eMBMS is a signaling channel within a cell of the cellular mobile radio network, via which a mobile radio device located in the present case at a road user can inform the cellular mobile radio network which content or channels it wants to receive. Ultimately, it can also be set whether the respective road user wants to receive a broadcast / multicast message or not, ie whether this service is activated for him or not.

It is conceivable that, on the one hand, the message is broadcast as a broadcast message and is accordingly received by all road users within the respective cell whose message receivers or UMTS receivers support eMBMS as a component of the mobile radio terminals included by the road users. It is also conceivable that the message is broadcast as a multicast message and can therefore only be received by those road users within a respective cell who previously registered themselves or their respective mobile radio terminals with the central server or a transmission unit coupled to it using an authentication procedure to have. In general, the use of the eMBMS results in savings both in the radio network and in the transport network.

The respective traffic sign information is preferably broadcast by means of SC-PTM.

Single-Cell Point-to-Multipoint (SC-PTM) is a special form of eMBMS-based data transmission in which the information is only transmitted to a large number of users in a single cell using eMBMS protocols. SC-PTM uses the eMBMS system architecture, whereby SC-PTM supports broadcast / multicast services via individual cells, whereby the broadcast / multicast area can be dynamically adapted from cell to cell, taking into account the distribution of road users. The cells affected by the broadcast / multicast can change dynamically. For this purpose, SC-PTM transmits the broadcast / multicast services using LTE-PDSCH (Physical Downlink Shared Channel). This can result in an enormous increase in efficiency, since multiple sending of messages to individual road users is not necessary if all road users affected by the traffic sign information are in one or a limited number of mobile radio cells or radio cells.

Alternatively, the traffic sign information is transmitted via a broadcast control channel (BCCH) of the LTE and / or the NR network. This is a downlink channel in the GSM, which a terminal, i. H. provides a road user with information, here traffic sign information, from a transmitting cell of the LTE and / or NR network. It is conceivable that the respective road users or the mobile radio terminals included or integrated therein may use the transmission control channel, i. H. Listen to BCCH regularly or are regularly reached or can be reached through the transmission control channel.

According to the invention, the traffic sign information is differentiated, evaluated and ranked relative to one another with respect to a respective change frequency with which the traffic sign information changes over time and is transmitted in accordance with this ranking with a transmission frequency assigned to a respective ranking position. As a result, the traffic sign information can be subdivided into, for example, highly dynamic, ie very rapidly changing traffic sign information, dynamic traffic sign information, ie traffic sign information that changes but does not change too quickly, and into static traffic sign information. Highly dynamic traffic sign information is generated, for example, by a traffic light as a traffic sign system. Dynamic traffic sign information is implemented, for example, by a barrier as a traffic sign system or, for example, by a digital speed display as a traffic sign system. Static traffic sign information will be For example, implemented by a stationary sign as a traffic sign system, such as a speed display on motorways, at construction sites or, for example, a display of deer crossing.

It is conceivable that, with the aid of the method according to the invention, only dynamic or highly dynamic traffic sign information is broadcast by the respective traffic sign systems via broadcast / multicast messages, while static traffic sign information is only displayed by the fixed traffic sign systems and / or via map material accessible to a particular navigation device of a road user be brought to the display.

For this, it is necessary that the static traffic sign information from the respective traffic sign systems is recorded once and / or at longer time intervals and stored in map material accessible to individual road users, so that when the map material is accessed by a respective road user, this traffic sign information of the respective traffic sign system is output and accordingly are displayed to the road user. Since this is static information, broadcast / multicast messages that are constantly updated and transmitted at a higher frequency are not necessary, since their information content with regard to the static traffic sign information of the respective traffic sign systems would not change and radio resources would therefore be used unnecessarily. This means that preferably highly dynamic and dynamic traffic sign information is broadcast by corresponding respective traffic sign systems with the aid of at least one broadcast / multicast message. In addition to the respective change frequency of the respective traffic sign information, it is conceivable to classify the traffic sign information also with regard to a respective importance in the order of priority mentioned above. This means that the individual traffic sign systems have to be classified with regard to their importance, in particular with regard to their importance for safety of the traffic or the respective road users. For example, the traffic sign information, ie the status of a respective traffic light or traffic light system, on the one hand, changes more quickly and, on the other hand, may also be rated higher in importance than a speed limit of a digital speed display or a ban on overtaking a digital traffic sign system. While the status of a traffic light is constantly changing and the status of the traffic light should therefore be transmitted at a relatively high frequency, e.g. once per second, the transmission of a respective status of a speed limit or a no-overtaking ban is less critical, with a time delay, for example of 10 s should not usually be a problem.

For the broadcast / multicast message to be transmitted, a message format with a data volume in the range of 30 bits to 40 bits, in particular in the range of 35 bits, is selected for each traffic sign system whose traffic sign information is to be broadcast in the broadcast / multicast message . A respective broadcast / multicast message to be broadcast includes for each traffic sign system whose traffic sign information is to be broadcast in the broadcast / multicast message, in particular information from the following group of information: Location information of the respective traffic sign system with a data volume in the range of 24 bits , Status information of the respective traffic sign system in the range of 3 to 6 bits, identity information of the respective traffic sign system in the range of up to 10 bits, information depending on a direction of the at least one road user relative to the respective traffic sign system, information depending on a speed of the at least one Road user.

In summary, a broadcast / multicast message comprises a data volume of around 35 bits per traffic sign system. It is conceivable to have one broadcast / multicast message for each traffic sign system for which traffic sign information is to be broadcast by multicast and / or broadcast to be provided, ie to be assigned to the respective traffic sign system, but in order to increase the efficiency of the system, the invention proposes that the traffic sign information from several traffic sign systems be summarized in a common single broadcast / multicast message and together as one message in the at least one cell of the cellular network. This at least one broadcast / multicast message is broadcast in at least one cell of the mobile radio network, in particular at least in the cell of the mobile radio network in which the traffic sign systems assigned to the broadcast / multicast message are located.

It can be assumed that the density of traffic sign systems is proportional to the population density, which is why the use of a cell structure of a cellular network proves to be extremely useful, since smaller cells are typically used in cities than in rural areas due to a higher capacity requirement. While typical urban mobile radio cells have a radius of <500 m, rural mobile radio cells usually have a radius in the range of 10 to 20 km. Based on typical scenarios, it can also be assumed that 100 to 250 traffic sign systems are to be found per mobile radio cell, of which 50% of the traffic sign systems are traffic sign systems with dynamic or highly dynamic traffic sign information. Accordingly, the amount of data to be transmitted per broadcast / multicast message is calculated as follows, taking into account the above-mentioned amount of data for each traffic sign system (35 bits x 250 traffic sign systems): 2 = 4,365 bits. This is a comparatively small amount of data. If the broadcast / multicast messages are to be transmitted once per second due to the dynamics of the traffic sign information they contain from the respective traffic sign systems, a total data rate of 4,375 bits / s results for the transmission via the cellular network.

A further division of the traffic sign systems according to dynamics and importance and the associated transmission frequency of the respective broadcast / multicast message assigned to the traffic sign systems reduces the necessary data rate accordingly. This means that the transmission frequency of a broadcast / multicast message from traffic sign systems, i.e. H. a so-called update rate is to be linked to the necessity of an up-to-dateness of a display of a status or of traffic sign information of the traffic sign systems assigned to the broadcast / multicast message and accordingly the status or the traffic sign information of the respective traffic sign systems depending on the importance of the respective traffic sign systems is or will be transmitted more or less often.

The location information from a traffic sign system comprised by the broadcast / multicast message is generally recorded by GPS and generally includes a geographical longitude and a geographical latitude (latitude) of the respective traffic sign system. This location information can be stored as a bit code, for which the message reserves a data volume of around 24 bits per traffic sign system. For a status of a respective traffic sign system, a data volume in the range of 6 bits per traffic sign system is reserved in a respective broadcast / multicast message, whereby, for example, in the case of a traffic light as a traffic sign system, one to two bits for coding the color, ie green, yellow or red, and the other bits can be reserved, for example, for a period of time, how long the respective color will last. The information contained in the broadcast / multicast message can be coded and uniquely recorded and transmitted by means of a respective bit sequence or a respective bit code. It is conceivable that bit sequences or bit codes of this type can be called up centrally in respective tables and for the respective road users or for the respective mobile radio terminals included by the respective road users or stored decentrally with the respective road users, so that the information to be transmitted is unique to a respective one Bit sequence can be assigned in the stored tables and therefore includes a one-to-one information content.

In a further possible embodiment, it is conceivable that the central server is located in a cloud.

The present invention also relates to a system for transmitting traffic sign information to at least one road user currently affected by the traffic sign information, in particular to at least one vehicle, via a cellular mobile radio network. The system according to the invention comprises at least one traffic sign system that is designed to provide the traffic sign information to a central server, and at least one central server that is designed to receive the traffic sign information provided by the at least one traffic sign system with a location of the at least one traffic sign system link and broadcast the traffic sign information of the at least one traffic sign system together with location information of the at least one traffic sign system within at least one cell of the cellular network by means of at least one broadcast / multicast message, whereby the at least one currently affected road user, which comprises a cellular terminal that is designed to to receive the at least one broadcast / multicast message which receives at least one broadcast / multicast message if the at least one is currently concerned fene road users are located in the cell within which the at least one broadcast / multicast message is broadcast, the traffic sign information being differentiated, evaluated and ranked relative to one another with respect to a respective change frequency with which the traffic sign information changes over time are transmitted in accordance with this ranking with a transmission frequency assigned to a respective ranking position.

In one embodiment, the cellular mobile radio network is an LTE network or an NR network.

In a further embodiment, the central server is located in a cloud.

The present invention also relates to a mobile radio terminal which is designed to be used to carry out an embodiment of the method according to the invention. The mobile radio terminal according to the invention is configured as part of a traffic participant currently affected by the traffic sign information to receive the at least one broadcast / multicast message transmitted by the central server within at least one cell of the mobile network if the at least one traffic participant is within at the time of transmission which is at least one cell.

The present invention also relates to a computer program product with a computer-readable medium and a computer program stored on the computer-readable medium with program code means which are configured to carry out the method according to the invention when the computer program is running on a processing unit. Furthermore, a computer program with program code means is claimed which is configured to carry out the method according to the invention when a computing unit is running.

Further advantages and configurations of the invention emerge from the description and the accompanying drawing.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention.

The invention is shown schematically in the drawing using an exemplary embodiment and is described in detail below with reference to the drawing.

Brief description of the drawing

Figure 1 shows an embodiment of a system according to the invention for performing an embodiment of the method according to the invention.

Figure 1 shows a schematic representation of an embodiment of a system 1 according to the invention for performing an embodiment of the method according to the invention. The system according to the invention for transmitting traffic sign information via a cellular mobile radio network 100 here comprises a traffic sign system 10, a central server 110 and a plurality of road users 11, each of which includes a mobile radio terminal 12 and all of which are located in a respective cell A, B, C or D of the cellular cellular network 100 are located. Two of the road users 11 are located in cell A, in which the traffic sign system 10 is also located, another road user 11 is currently still in the neighboring cell B, but is approaching cell A. The cellular network 100 has a cellular network Access network 101 and a core network 102. The core network 102 is only shown schematically by means of a cloud representation. The cellular mobile radio network 100, in particular the core network 102, usually has various network elements, not shown here, such as an MSC (Mobile Switching Center) as a component of the switching subsystem (SSS), an SGSN (Serving GPRS Support Node), an MME (Mobility Management Entity) ), etc. These network elements are hierarchically higher network elements than the base stations (Base Transceiver Station (BTS)) 13. The traffic sign system 10 shown here is designed to transmit traffic sign information, in particular status information of its current operating status and identity information about its identity, to the central server 110 or to the central server 110 to provide. The central server 110 is designed to receive the traffic sign information provided by the traffic sign system 10. It is conceivable that the central server 110 retrieves the traffic sign information from the traffic sign system 10, in particular at regular intervals, or alternatively, the traffic sign system 10 itself actively sends the traffic sign information, in particular at regular time intervals, to the central server 110 sends. The traffic sign system 10 and the central server 110 communicate via a base station 13 located in cell A of the traffic sign system 10, which in turn is coupled to a switching system (SSS), also not shown here, via a base station controller (BSC), also not shown here, and ultimately with the For example, central server 110 located in a cloud can exchange data. The data exchange between traffic sign system 10 and base station 13 takes place via radio. The broadcast message to be sent out is broadcast by the central server 110 and via SSS, BSC and respective base stations 13 in cells A, B, C and / or D selected in advance by the central server 110. As a rule, the broadcast message is broadcast at least in the cell in which the respective traffic sign system is located, ie here in cell A. It is conceivable to broadcast the broadcast message in cells B and C adjacent to cell A. As a rule, there are a large number of traffic sign systems in the cellular mobile radio network 100, each of which provides the relevant traffic sign information, such as status information, identity information, etc., to the central server 110. On average, there are around 100 to 250 traffic sign systems per cell of the cellular network, around half of which provide changing traffic sign information, which is why these traffic sign systems are also referred to as dynamic traffic sign systems. In order to be able to provide the traffic sign information, each of the traffic sign systems 10 includes an operation module that logs a respective status of an operation of the traffic sign system, an identity module that includes the identity of the respective traffic sign system, and a communication module that is designed to provide the status information and the identity information of the traffic sign system 10 to the central server 110, the traffic sign information being transmitted by radio via the cellular network.

The central server 110, which is located in a cloud, for example, is designed to receive and process the traffic sign information. There a location of the at least one traffic sign system 10 is linked to the identity information of the traffic sign system 10 and the status information of the traffic sign system 10. This means that, for example, it can be stored in a table in the central server 110 which traffic sign system 10 is located at which location, the location of a traffic sign system usually being able to be determined, for example, via GPS.

As an alternative to this, it is also conceivable that the traffic sign system 10 itself transmits location information together with the identity information, so that the central server 110 immediately receives the location together with the traffic sign information. Furthermore, the central server 110 is designed to bring the traffic sign information of the at least one traffic sign system 10 together with the location information of the traffic sign system 10 in a message format in order to broadcast this generated message as a broadcast message at least within cell A of the mobile network in which the Road users 11 affected by the traffic sign information are currently located. The road users 11 affected by the traffic sign information are generally those road users who are located in the vicinity of the respective traffic sign system 10, ie. H. usually within the same cell A as the traffic sign system 10 or at least within one of the cells B, C or D adjacent to the cell A of the traffic sign system 10.

Furthermore, it is often important how a particular road user 11 moves relative to the traffic sign system 10, ie whether he is approaching the traffic sign system 10 or driving away from it. In addition, it can also be important at what speed the road user 11 moves towards the traffic sign system 10, both with regard to the information to be transmitted to him and with regard to the cell in which the road user 11 is at the time of transmission the traffic sign information is located. When the traffic sign information is received, it is the task of the central server 110 to provide the traffic sign information to be evaluated in connection with the respective location of a respective traffic sign system 10 in such a way that it becomes clear in which cell or cells the traffic sign information is to be broadcast in order to be able to reach the subscribers 11 affected by the traffic sign information of the traffic sign system 10 with the broadcast message . Because it is a broadcast message, when the broadcast message is broadcast within a cell, it is usually not possible to further differentiate which road user within the cell receives the broadcast message or not, unless the road user himself or herself is able for his part to activate or deactivate a function on his mobile radio terminal 12 with which he can determine whether he can receive broadcast messages from the central server 110 or not.

As an alternative to broadcasting a broadcast message, a multicast message can also be broadcast, which can then only be received by those road users 11 within the cell in which the multicast message can be broadcast who are themselves or their respective mobile radio terminals 12 have previously registered by means of an authentication method with the central server 110 or with a transmission unit, not shown here, coupled to it.

If there are several traffic sign systems 10 in a cell A, from which traffic sign information is to be broadcast at the same update rate, this is evaluated accordingly by the server 110 using the respective location information of the respective traffic sign systems 10 and the traffic sign information to be broadcast from the respective traffic sign systems 10 and the Traffic sign information from all these traffic sign systems is then packed together with the respective location information of the respective traffic sign systems into a broadcast / multicast message common for these traffic sign systems and broadcast in the form of this common broadcast / multicast message.

The broadcast / multicast message generally comprises a data volume of 30 to 40 bits, in particular 35 bits, per traffic sign system. This means that each traffic sign system of these traffic sign systems is assigned a data volume of 30 to 40 bits, in particular 35 bits, within the common broadcast / multicast message.

Further information on the extent to which a respective road user 11 is affected by the traffic sign information of a respective traffic sign system 10 is ultimately derived directly from the broadcast / multicast message itself, which in addition to the status information, the location of the traffic sign system 10 and the identity of the traffic sign system 10 in the Usually also includes information about which speeds traveled by the respective road users 11 and in which direction are actually affected by the traffic sign information of the respective traffic sign system 10. It is conceivable, for example, that some of the traffic sign information only relates to vehicles of a certain type which, for example, are only allowed to drive below a certain speed.

Furthermore, it is conceivable, for example, with regard to a traffic light system, that vehicles which move in a specific direction relative to the traffic sign system are affected or not affected by the status information of the traffic sign system. This information is ultimately derived from the broadcast / multicast message itself, but can be extracted by a respective road user 11 immediately upon perception and knowledge of the broadcast / multicast message by means of his mobile radio terminal 12 or by means of a filter implemented therein, so that each road user 11 can quickly determine the extent to which he himself is affected by the broadcast / multicast message or not.

Claims (14)

1. A method for transmitting traffic sign information to at least one road user (11) currently affected by the traffic sign information, in particular to at least one vehicle, via a cellular mobile radio network (100), in which the traffic sign information is transmitted from at least one traffic sign system (10) to a central server (110), the transmitted traffic sign information is linked to a location of the at least one traffic sign system (10) and is transmitted together with location information of the at least one traffic sign system (10) by the central server (110) within at least one cell (A, B) of the mobile radio network (100) by means of at least one broadcast/multicast message, the at least one road user (11) being located within the at least one cell (A, B) at the time of the transmission, characterized in that, with regard to a respective change frequency with which the respective traffic sign information changes temporally, the traffic sign information is differentiated, evaluated and arranged in a ranking relative to one another and is transmitted respectively in accordance with such ranking with a transmission frequency assigned to a respective ranking position.
2. The method according to claim 1, in which, before the traffic sign information is transmitted, it is calculated in which at least one cell (A, B) the at least one road user (11) currently affected by the traffic sign information will be located at the time of the transmission of the broadcasting/multicast message, and this at least one cell (A, B) is determined as the at least one cell within which the broadcasting/multicast message will be transmitted.
3. The method according to one of the preceding claims, in which the traffic sign information is transmitted by a plurality of traffic sign systems (10) to the central server (110) and respective traffic sign information is linked to a respective location of a respective traffic sign system (10) of the plurality of traffic sign systems (10) and is transmitted together with respective location information of the respective traffic sign system (10) by the central server (110) within the at least one cell (A, B) of the mobile radio network by means of the at least one broadcast/multicast message.
4. The method according to one of the preceding claims, in which a network corresponding to the LTE or NR standard is selected as the mobile radio network.
5. The method according to claim 4, in which the traffic sign information is transmitted by means of eMBMS or SC-PTM using an eMBMS protocol.
6. The method according to claim 4, in which the traffic sign information is transmitted via a BCCH of the LTE or NR network.
7. The method according to one of the preceding claims, in which the traffic sign information is ranked with regard to a respective importance in addition to the respective change frequency.
8. The method according to one of the preceding claims, in which a message format with a data quantity in the range of 30 bits to 40 bits, in particular 35 bits, is selected for the at least one broadcast/multicast message for the at least one traffic sign system.
9. The method according to claim 8, in which the broadcast/multicast message comprises information from the following group of information:
   Location information of the at least one traffic sign system with a data quantity in the range of 24 bits, status information of the at least one traffic sign system with a data quantity in the range of 3 to 6 bits, identity information of the at least one traffic sign system, information depending on a direction of the at least one road user relative to the at least one traffic sign system, information depending on a speed of the at least one road user.
10. A system for transmitting traffic sign information to at least one road user (11) currently affected by the traffic sign information, in particular to at least one vehicle, via a cellular mobile radio network (100), at least comprising: at least one traffic sign system (10), which is designed to provide the traffic sign information to a central server (110), the at least one central server (110), which is designed to receive the traffic sign information provided by the at least one traffic sign system (10), to link said traffic sign information with a location of the at least one traffic sign system (10), and to transmit the traffic sign information of the at least one traffic sign system (10) together with location information of the traffic sign system (10) within a cell (A, B) of the mobile radio network (100) by means of at least one broadcast/multicast message, so that the at least one currently affected road user (11), who comprises a mobile radio terminal designed to receive the broadcast/multicast message, can receive the at least one broadcast/multicast message when the at least one currently affected road user (11) is located in the cell (A, B) within which the at least one broadcast/multicast message is transmitted, characterized in that
    with regard to a respective change frequency with which the respective traffic sign information changes temporally, the traffic sign information is differentiated, evaluated and arranged in a ranking relative to one another and is transmitted respectively in accordance with such ranking with a transmission frequency assigned to a respective ranking position.
11. The system according to claim 10, in which the cellular mobile radio network is an LTE network or an NR network.
12. A mobile radio terminal configured to be used for carrying out a method according to one of claims 1 to 9 and to receive, as part of a road user (11) currently affected by the traffic sign information, the at least one broadcast/multicast message transmitted by the central server (110) within at least one cell (A, B) of the mobile radio network (100).
13. A computer program product with a computer-readable medium and a computer program with program code means stored on the computer-readable medium, the program code means being configured to carry out a method according to one of claims 1 to 9 when the computer program is executed on a computing unit.
14. A computer program with program code means, the computer program being configured to carry out a method according to one of claims 1 to 9 when executed on a computing unit.

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