Method for operating a roadside network unit and roadside network unit

Abstract

A method for operating a roadside network unit is proposed, the method comprising: determining (302) valid data for sending to at least one other roadside network unit; providing (304) these valid data for sending on a sidelink channel within a licensed frequency range and / or for sending on a self-organizing channel within an unlicensed frequency range; and sending (304) these valid data on the sidelink channel within the licensed frequency range and / or on the self-organizing channel within the unlicensed frequency range.

Description

Technical Field

[0001] The invention relates to a method for operating a roadside network unit and a roadside network unit. Background Art

[0002] It is known that today's vehicles can already exchange information with other vehicles in their vicinity (V2V: Vehicle to Vehicle). Vehicles can also communicate wirelessly with roadside infrastructure (V2I: Vehicle to Infrastructure). Similarly, vehicles can communicate wirelessly with backend servers on the Internet (V2N: Vehicle to Network) or with pedestrian terminals (V2P: Vehicle to Person). This communication as a whole is also referred to as vehicle-to-everything (V2X).

[0003] The development of new functions and services in the automotive industry, such as autonomous driving, benefits from V2X. Traffic safety, driving comfort and energy efficiency can be improved. For car manufacturers, automotive suppliers and other service providers, this leads to new products and business models.

[0004] The first generation of V2X applications, which should be used in the next few years, mainly involves applications on the road. The goal is to provide drivers with information about the road environment. Vehicles periodically provide status information (such as position, speed, acceleration, etc.) and / or event information (rescue operations, stranded vehicles, traffic jams). This information is usually sent locally in the form of short messages. Neighboring vehicles can send this event-based information to the central network unit (base station, backend).

[0005] There are currently two competing technologies for V2X Direct Device-to-Device (D2D) communication. The first technology is based on the IEEE 802.11p standard in terms of radio technology, which forms the basis for the overall standard DSRC (Dedicated Short Range Communication) in the United States and the overall standard ETSI ITS G5 (ETSI: European Telecommunications Standards Institute; ITS: Intelligent Transport Systems) in Europe. The second technology is based on 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) and is also known under the abbreviation LTE-V2X. Further developments of the LTE-V2X technology are expected in the context of 5G (5th generation mobile networks).

[0006] The IEEE 802.11p standard uses the PHY layer of the IEEE 802.11a standard based on Orthogonal Frequency Division Multiplexing (OFDM) with some modifications. The MAC layer is based on Enhanced Distributed Channel Access (EDCA), which is contention-based. Carrier Sense Multiple Access (CSMA) with Collision Avoidance (CSMA / CA) is also used. CSMA / CA follows the Listen-Before-Talk principle in order to reduce conflicts on the channel to a minimum. If a network unit (a vehicle in this context) has data to transmit, the network unit performs channel measurements in order to check whether the channel is occupied. If the channel is considered empty, the network unit with the planned transmission waits for a randomly determined time and then starts the transmission. If the channel is occupied during the channel measurement, the network unit will perform a backoff procedure, that is, the network unit waits for a randomly determined time period for the next channel access. The more network units that attempt to transmit in a geographical area, the higher the probability that the network unit will delay its transmission, which leads to an overall increase in the delay in the network. Compared with other WLAN standards based on IEEE 802.11, the IEEE 802.11p standard offers advantages in terms of latency and signaling overhead and is adapted to the application case V2V.

[0007] The LTE extension for V2X, starting from 3GPP Release 14, proposes the use of licensed and / or unlicensed spectrum for communication. V2V communication is based on a direct device-to-device interface (also called a sidelink interface on the physical layer). Unlike 802.11p, transmission is implemented in a cell-protected manner, that is, it is carried out in a planned manner by the network. Transmission rights are issued by a scheduling unit in the base station so that conflicts are avoided and interference is reduced to a minimum. Control by the base station can only be performed in areas where the base station signal is available (in-coverage). In cases where no base station signal is provided (out-of-coverage), communication is carried out via the sidelink using predefined parameters.

[0008] During the development of communication standards, different standards may be proposed for the same frequency range, for example based on different applications or development activities from different technical fields. As a result, different wireless communication systems may transmit in the same frequency range and performance may be degraded for both technologies.

[0009] Therefore, an objective technical task may be formulated as follows: a coexistence mechanism for two different wireless communication technologies should be created in order to fairly divide the existing resources. Summary of the invention

[0010] The problem on which the invention is based is solved by a method according to the invention for operating a road-side network unit and by a road-side network unit according to the invention.

[0011] According to a first aspect, a method for operating a road-side network unit is proposed, the method comprising: determining valid data for sending to at least one other road-side network unit; providing these valid data for sending on a side link channel within a licensed frequency range or for sending on a self-organizing channel within an unlicensed frequency range; and sending these valid data on the side link channel within the licensed frequency range and / or on the self-organizing channel within the unlicensed frequency range.

[0012] According to a second aspect, a roadside network unit is provided. The roadside network unit comprises a processor for determining valid data for transmission to at least one other roadside network unit and for providing the valid data for transmission on a sidelink channel within a licensed frequency range or for transmission on an ad hoc channel within an unlicensed frequency range. The network unit encloses two transceivers for a corresponding wireless communication network for transmitting the valid data on a sidelink channel within a licensed frequency range or on an ad hoc channel within an unlicensed frequency range.

[0013] Since these useful data are sent on the sidelink channel in the licensed frequency range and / or on the ad hoc channel in the unlicensed frequency range, a favorable division of the communication in these two frequency ranges is achieved. The higher the interspersed rate of the network units constructed according to the second aspect, the better this separation of the communication in these two frequency ranges works. Correspondingly, the collision probability on the sidelink channel and on the ad hoc channel is reduced and both channels benefit. Therefore, the advantages of two network technologies can be used, wherein the collision probability is reduced at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Further features and advantages are apparent from the following description of exemplary embodiments. In the drawings:

[0015] Figure 1A first cell-based wireless communication network and a second wireless communication network are shown;

[0016] Figure 2 A schematic flow chart is shown;

[0017] Figure 3 and 4 Schematic block diagrams are shown respectively;

[0018] Figure 5 shows a schematic sequence diagram; and

[0019] Figure 6 A schematic structure of a data packet is shown. DETAILED DESCRIPTION

[0020] Figure 1 A cell-based wireless communication network CELL and a self-organizing wireless communication network VANET are shown. The cell-based wireless communication network CELL includes a network unit BS on the network infrastructure side, a road-side network unit UE1, and a road-side network unit UE2. The network unit BS on the network infrastructure side includes a processor P_BS, a storage element M_BS, and a transceiver TC_BS. The network unit BS on the network infrastructure side can also be called a base station or eNodeB. The network unit BS on the network infrastructure side is connected to a fixed antenna A_BS to send data on a downlink channel DC and receive data on an uplink channel UC. Antenna A_BS, for example, includes multiple antennas and is implemented as a remote radio head (Remote Radio Head), i.e., RRH. The network unit BS on the network infrastructure side and the antenna A_BS provide a cell C, within which the road-side network units UE1 and UE2 communicate with the network unit BS. Of course, the network unit BS on the network infrastructure side can also be constructed in a distributed manner within the framework of virtualization and consist of decentralized network units. The network unit BS, UE1, and UE2 are configured, for example, according to the LTE-V2X standard.

[0021] The roadside network unit UE1 includes a processor P1, a storage element M1, a transceiver TA1 and a transceiver TC1. The transceiver TA1 is connected to the antenna AA1. The transceiver TC1 is connected to the antenna AC1. In one embodiment, the antennas AA1 and AC1 are implemented as a common antenna element. The roadside network unit UE2 includes a processor P2, a storage element M2, a transceiver TC2 and an antenna A2. The storage elements M1, M2 and M3 store corresponding computer programs, which implement the methods disclosed in this specification when implemented on the corresponding processors P1, P2 and P3. Alternatively, the processors P1, P2 and P3 are implemented as ASICs.

[0022] The two roadside network units UE1, UE2 are within the cell C and can receive data on the downlink channel DC and send data on the uplink channel UC. The two roadside network units UE1, UE2 can communicate directly with each other in the unlicensed frequency range NLFB via the sidelink channel SC1 and in the licensed frequency range LFB via the sidelink channel SC2.

[0023] National authorities such as the Federal Network Agency of the Federal Republic of Germany formulate frequency use plans, which include, for example, licenses for corresponding network operators. Within the framework of the assigned licenses, network operators are allowed to use network infrastructure and terminals within the assigned, i.e. licensed, frequency ranges or spectra, either individually or as members of a user group. In contrast, there are frequency ranges or spectra that are not assigned to network operators but can be used freely under certain boundary conditions, such as reduced transmit / receive power.

[0024] In this description, reference is made to a unique uplink channel UC and a unique downlink channel DC. For example, the uplink channel UC and the downlink channel DC comprise corresponding subchannels, that is to say multiple channels are provided in the uplink as well as in the downlink. The same applies to the sidelink channels SC1, SC2.

[0025] The wireless communication network VANET comprises a roadside network unit UE1 and a network unit NE1. The network unit NE1 comprises a processor P3, a storage element M3, a transceiver TA3 and an antenna A3. The transceivers TA1 and TA3 are configured, for example, according to the IEEE 802.11p standard. The network units UE1 and NE1 communicate directly with each other via a self-organizing channel ADCH in an unlicensed frequency range NLFB. The self-organizing channel ADCH is arbitrated by the transceivers TA1 and TA3 via the CSMA / CA protocol (CSMA / CA: Carrier Sense Multiple Access / Collision Avoidance).

[0026] The network elements NE1 and UE1 are located in the vicinity of the network element UE2. Due to this proximity, the corresponding transmission powers are sufficient to cause the transmissions on the channels ADCH and SC1 to adversely affect each other, which are transmitted in the same unlicensed frequency range NLFB. The object of this specification is to reduce this adverse mutual influence.

[0027] The roadside network units UE1, UE2 and NE1 are arranged in the corresponding motor vehicles vehic1, vehic2, vehic3 and are connected to control devices (not shown) arranged there, respectively, for data exchange. In an alternative embodiment, the roadside network units UE1, UE2 and NE1 are part of the control devices in the corresponding motor vehicles vehic1, vehic2, vehic3. In another alternative embodiment, the roadside network units UE1, UE2 and NE1 are arranged in a static infrastructure such as a traffic light, rather than in the motor vehicle.

[0028] The sidelink channels SC1, SC2 and the sidelink in general are defined, for example, by the document 3GPP TS 36.300 V14.2.0 (2017-03), which is incorporated into the present specification by reference. The sidelink includes sidelink discovery, sidelink communication and V2X sidelink communication between network elements UE1, UE2. The sidelink uses uplink resources and a physical channel structure similar to that of the uplink. Therefore, the sidelink differs from the uplink in terms of the physical channel.

[0029] The sidelink is limited to cluster transmissions for the Physical Sidelink Channel. The sidelink also uses a 1 symbol gap at the end of each Sidelink-Subframe. For V2X sidelink communications, the PSCCH, Physical Sidelink Control Channel, and the PSSCH, Physical Sidelink Shared Channel, are transmitted in the same subframe. The sidelink channels SC1, SC2 are, for example, PSSCH.

[0030] The physical layer processing of the transmission channels in the sidelink differs from the uplink transmission in the following steps: Scrambling: For PSDCH, i.e. the Physical Sidelink Discovery Channel, and PSCCH, the scrambling is not specific to the network element; Modulation: 64QAM and 256QAM are not supported for the sidelink (QAM: Quadrature Amplitude Modulation). PSCCH specifies the sidelink resources and other transmission parameters used by the corresponding network elements UE1, UE2 for PSSCH.

[0031] For PSDCH, PSCCH and PSSCH demodulation, the reference signal is transmitted similarly to the uplink demodulation reference signal in the 4th symbol of the time slot in the standard CP, i.e., the cyclic prefix (Cyclic Prefix) and in the 3rd symbol of the time slot in the extended CP. The sidelink demodulation reference signal sequence length corresponds to the size of the allocated resources (the number of subcarriers). For V2X sidelink communication, the reference signal is transmitted in the 3rd and 6th symbols of the first time slot in the CP and in the 2nd and 5th symbols of the second time slot in the CP. For PSDCH and PSCCH, the reference signal is generated based on a fixed basic sequence, a cyclic shift and an orthogonal cover code. For V2X sidelink communication, the cyclic shift for PSCCH is randomly selected at each transmission.

[0032] For the measurement of the corresponding sidelink channels SC1, SC2, the following possibilities are provided on the side of the network units UE1, UE2: sidelink reference signal received power (S-RSRP); sidelink discovery reference signal received power (SD-RSRP); PSSCH reference signal received power (PSSCH-RSRP); signal strength indicator (S-RSSI) for the sidelink reference signal.

[0033] Self-organizing channels ADCH and self-organizing wireless communication networks VANET are defined, for example, by the IEEE standard "802.11p-2010--IEEE Standard for Information technology-Local and metropolitan area networks-Specific requirements--Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments", which is included in this specification by reference. IEEE802.11p is a standard for extending the WLAN standard IEEE 802.11. The goal direction of IEEE 802.11p is to establish WLAN technology in passenger-vehicle vehicles and to provide a reliable interface for the application of intelligent transportation systems (Intelligent Transport Systems, ITS in English). IEEE 802.11p is also the basis for dedicated short-range communication (Dedicated Short Range Communication, DSRC) in the frequency band from 5.85 to 5.925 GHz. In order to avoid confusion with the European version of DSRC, the term ITS-G5 is preferred instead of DSRC, especially in Europe.

[0034] The document "ETSI TS 302663 V1.2.0 (2012-11)" which is included in this description by reference, describes the two lowest layers of the ITS-G5 technology (ITS-G5: Intelligent Transport Systems operating in the 5 GHz frequency band), namely the physical layer and the data link layer. The transceivers TA1 and TA3 implement these two lowest layers and the corresponding functions according to "ETSI TS 102687 V1.1.1 (2011-07)" for example, in order to use the self-organizing channel ADCH. In order to use the self-organizing channel ADCH, the following unlicensed frequency ranges are provided in Europe, which are part of the unlicensed frequency range NLFB: 1) ITS-G5A for safety-related applications in the frequency range from 5.875 GHz to 5.905 GHz; 2) ITS-G5B for non-safety-related applications in the frequency range from 5.855 GHz to 5.875 GHz; and 3) ITS-G5D for ITS applications operating in the frequency range from 5.905 GHz to 5.925 GHz. ITS-G5 enables communication between two network units UE1 and UE2 outside the environment of a base station. ITS-G5 enables the immediate exchange of data frames and avoids the management overhead used when setting up the network.

[0035] The document "ETSI TS102687 V1.1.1 (2011-07)" included in this specification by reference describes "Decentralized Congestion Control Mechanisms" for ITS-G5. The self-organizing channel ADCH is used in particular to exchange data on traffic safety and traffic efficiency. Transceivers TA1 and TA3, for example, implement the functions described in the document "ETSI TS102687 V1.1.1 (2011-07)". The applications and services in ITS-G5 are based on the cooperative behavior of road-side network units, which form a self-organizing (Adhoc) network VANET (VANET: vehicular ad hoc network). The self-organizing network VANET enables time-critical road traffic applications, in which fast information exchange is required in order to warn the driver and / or vehicle in a timely manner and to assist the driver and / or vehicle. In order to ensure the normal function of the self-organizing network VANET, the self-organizing channel ADCH for ITS-G5 uses "Decentralized Congestion Control Mechanisms (DCC)". DCC has the following functions, which are located at multiple layers of the ITS architecture. The DCC mechanism is based on the understanding of the channel. Channel state information is obtained through channel detection. The channel state information can be obtained through TPC (transmit power control), TRC (transmit rate control) and TDC (transmit data rate control) methods. These methods determine the channel state information based on the received signal level threshold or preamble information of the detected packet.

[0036] Figure 2 Shown is the operation Figure 1 Schematic flow chart of the roadside network unit UE1 in FIG. In step 202, valid data for sending to other roadside network units is determined. In step 204, the determined valid data is provided for sending on a sidelink channel within a licensed frequency range or for sending on an ad hoc channel within an unlicensed frequency range. In step 206, the valid data is either sent on a sidelink channel within a licensed frequency range or sent on an ad hoc channel within an unlicensed frequency range.

[0037] Figure 3 Shown is the operation Figure 1Schematic block diagram of a roadside network unit UE1 in FIG. Block 302 is assigned to the application layer APP. Block 304 is assigned to the device layer FAC. Block 302 determines valid data N1. Block 304 determines valid data N2. The valid data N1, N2 can also be referred to as payload. Block 306 determines to which of the three waiting queues Q1, Q2 and Q3 the valid data N1, N2 are provided. Block 306 can also be referred to as a communication manager, for example.

[0038] Blocks 308 and 310 are assigned to the PDCP layer (PDCP: Packet Data Convergence Protocol). Blocks 308 and 310 include, for example, functionality according to the document "3GPP TS 36.323 V14.3.0 (2017-06)", which is incorporated into the present description by reference. In order to distinguish between two types of wireless communication networks used and the corresponding protocol stacks, block 310 embeds a corresponding network identifier into the generated data packet PDCP PDU (PDU: Protocol Data Unit). By including, for example, this network identifier of a single bit, it is advantageously possible to distinguish on the receiving side: to which unit or protocol stack the received data packet can be assigned and thereby provided.

[0039] Block 312 is assigned to the RLC layer (RLC: Radio Link Control) and comprises, for example, functionality in accordance with the document “3GPP TS 36.322 V14.0.0 (2017-03)”, which is incorporated into the present description by reference. Block 312 receives the data obtained from block 308 and determines the data forwarded to block 314. Block 314 is assigned to the MAC layer (MAC: Media Access Control) and comprises, for example, functionality in accordance with the document “3GPP TS 36.323 V14.3.0 (2017-06)”, which is incorporated into the present description by reference. Block 314 communicates with block 316 assigned to the physical layer PHY. Block 316 comprises, for example, functionality in accordance with the document “3GPP TS 36.201 V14.1.0 (2017-03)”, which is incorporated into the present description by reference. Box 316 Figure 1 The transceiver TC1 includes blocks 314 and 316, for example.

[0040] Block 318 is assigned to the MAC layer MAC and comprises, for example, functionality according to the document "ETSI EN 302663 V1.2.0 (2012-11)", which is incorporated into this specification by reference. Block 318 obtains the data to be sent from block 310 or from the third waiting queue Q3. Block 320 is assigned to the physical layer PHY and Figure 1 The valid data N1, N2 are sent on the ad hoc channel ADCH in the . Block 320 comprises, for example, functionality according to the document “ETSI ES202663 V1.1.0 (2009-11)”, which is incorporated into the present document by reference. The transceiver TA1 comprises, for example, blocks 318 and 320.

[0041] If the useful data N1, N2 are present, for example, as IP packets (IP: Internet Protocol) or as UDP packets (UDP: User Datagram Protocol), the useful data N1, N2 are placed in one of the two waiting queues Q1, Q2 by block 306. Block 306 makes a decision on which of the waiting queues Q1, Q2 the useful data N1, N2 is to be placed, based on at least one of the following information: 1) the type of data in the IP packet, i.e., for example, CAM or DENM; 2) the type of the packet in the packet; 3) the type of the packet in the packet; 4) the type of the packet in the packet; 5) the type of the packet in the packet; 6) the type of the packet in the packet; 7) the type of the packet in the packet; 8) the type of the packet in the packet; 9) the type of the packet in the packet; 10) the type of the packet in the packet; 11) the type of the packet in the packet; 12) the type of the packet in the packet; 13) the type of the packet in the packet; 14) the type of the packet in the packet; 15) the type of the packet in the packet; 16) the type of the packet in the packet; 17) the type of the packet in the packet; 18) the type of the packet in the packet; 19) the type of the packet in the packet; 20) the type of the packet in the packet; 21) the type of the packet in the packet; 22) the type of the packet in the packet; 23) the type of the packet in the packet; 24) the type of the packet in the packet; 25) the type of the packet in the packet; 26) the type of the packet in the packet; 27) the type of the packet in the packet; 28) the type of the packet in the packet; 29) the type of the packet in the packet; 30 Figure 1 Channel load on channels SC2 and ADCH in the channel, such as channel state information CSI1 and / or CSI2; 3) according to transmission requirements such as delay, reliability, and data volume, which are known from the application layer; 4) Figure 1 The availability of one and / or other channels SC2, ADCH.

[0042] If the valid data N1, N2 are of the CAM or DENM type described below, for example, the valid data N1, N2 are placed in the third waiting queue Q3 by block 306. Of course, in addition to the types CAM and DENM, other types are also possible.

[0043] CAM (CAM: Cooperative Awareness Message) type messages are defined in the document "ETSI EN 302637-2 V1.3.1 (2014-09)", which is included in this specification by reference. In road traffic, cooperative awareness means that traffic members and roadside infrastructure inform each other of their position, driving dynamics and characteristics. Traffic members are all types of road vehicles, such as cars, trucks, motorcycles, bicycles and pedestrians, as well as roadside infrastructure including traffic signs, traffic lights or roadblocks and gates. CAM messages are sent at regular time intervals, that is to say periodically. CAM-type messages indicating emergency vehicles or traffic jams are used not only for traffic efficiency but also for traffic safety.

[0044] Messages of the DENM (DENM: Decentralized Environmental Notification Message) type are defined in the document "ETSI EN 302637-3 V1.2.1 (2014-09)", which is included in this specification by reference. The DEN service (DEN: Decentralized Environmental Notification) supports the RHW application (RHW: Road Hazard Warning). The DEN service generates, manages and processes messages of the DENM type. Messages of the DENM type contain information about road hazards or abnormal traffic conditions and the corresponding locations. The DEN service provides the DENM as a payload to the ITS network layer and transport layer for message propagation. The ITS application propagates the DENM type messages to these network elements through direct vehicle-to-vehicle or vehicle-to-infrastructure communication on the self-organizing channel ADCH. On the receiving side, the DEN service of the receiving ITS-S processes the received DENM type messages and provides the DENM content to the application. If the information about the road traffic conditions is relevant for the driver, the application transmits this information to the driver or the vehicle, who can then take corresponding measures to react accordingly to the situation.

[0045] Alternatively to the type of valid data N1, N2 or in addition to the type of valid data N1, N2, a decision is made based on local channel state information CSI1 and / or CSI2 to which of the three waiting queues Q1 to Q3 the valid data N1, N2 is placed. The local channel state information CSI1 is determined by box 314 and includes, for example, the ratio of scheduled radio resources to idle radio resources on the sidelink channel within the licensed frequency range. The local channel state information CSI2 is determined by box 318 and includes, for example, the number of roadside network units that can be directly reached via the self-organizing channel, that is, the local density of roadside network units. The channel state information CSI2 indicates, for example: the self-organizing channel has a high occupancy rate in the unlicensed frequency range, that is, the number of reachable roadside network units detected in the vicinity exceeds a threshold. In the case of high occupancy of the self-organizing channel, box 306 decides to place the valid data N1, N2 in the first waiting queue Q1.

[0046] In one embodiment, the local channel state information CSI1 and CSI2 are compared with each other, and based on the comparison, it is determined into which of the waiting queues Q1, Q2 or Q3 the valid data N1, N2 is to be placed.

[0047] Placing data in the waiting queue Q1 means: sending the placed data on the sidelink channel within the licensed frequency range. Placing data in the waiting queue Q2 means: sending the placed data on the self-organizing channel within the unlicensed frequency range with the intervention of the block 310 assigned to the PDCP layer. Placing data in the waiting queue Q3 means: sending the placed data on the self-organizing channel within the unlicensed frequency range, wherein the placed data is directly received by the block 318 assigned to the MAC layer, that is, directly transmitted. This means: the valid data N1, N2 transmitted to the waiting queue Q3 from the application layer APP or the device layer FAC is directly provided to the MAC layer from there for transmission via the self-organizing channel.

[0048] Blocks 308, 310, 312, 314 and 316 are all part of the LTE-V protocol stack S-LTE-V. Blocks 318 and 320 are part of the ITS-G5 protocol stack S-ITS-G5, in which only the two lowest layers MAC and PHY are implemented in the present case and the remaining layers are not only set for ITS-G5. This advantageously makes it possible to have only one simplified transceiver TC1.

[0049] Figure 4 Shown is the operation Figure 1 Schematic block diagram of the roadside network unit UE1 in FIG. Figure 3, showing the reception of valid data N1, N2. Block 402 determines from the data provided by block 318 whether valid data N1, N2 is provided directly to blocks 302 or 304, or whether the received data includes a PDCP packet PDU and is therefore provided to block 310.

[0050] Figure 5 A schematic sequence diagram with sequences S1 and S2 is shown. In step 500, valid data N1 is determined at the application layer. In step 502, it is decided that the determined valid data N1 should be sent on the self-organizing channel ADCH. In step 504, the valid data N1 is provided to the transceiver TA1. In step 506, the transceiver TA1 performs arbitration on the self-organizing channel ADCH. If the arbitration is successful, that is, the self-organizing channel ADCH for data transmission is idle, then in step 508, the transceiver TA1 sends the valid data N1 on the self-organizing channel ADCH in the unlicensed frequency range.

[0051] In step 510, valid data N1 is determined at the application layer. In step 512, it is decided that the determined valid data N1 should be sent on the sidelink channel SC2. In step 514, the processor P1 provides the valid data N1 to the transceiver TC1 for transmission. In step 516, the transceiver TC1 transmits a scheduling request (Scheduling-Request) message BSR, such as a buffer status report (Buffer Status Report) to the network infrastructure side network unit BS on the uplink channel UC. A scheduling grant (Scheduling-Grant) message G is determined in step 518 and transmitted in step 520 to the road side network unit UE1 on the downlink channel DC. The scheduling grant message G1 includes an allocation of radio resources on the sidelink channel SC2. On the allocated radio resources of the sidelink channel SC2, the determined valid data N1 is sent to the road side network unit UE2 in step 522.

[0052] In one embodiment of step 502 and step 512, the determined useful data N1 are associated with a requirement for transmission. This requirement can be, for example, a traffic class of useful data N1, N2, in particular a traffic class according to the document "ESTI 636-4-2 V1.1.1 (2013-10)", which is part of the present description by reference. The traffic class leading to the transmission on the self-organizing channel ADCH includes, for example, useful data of the DENM and CAM types as well as other possible types of useful data / messages. The traffic class leading to the transmission on the sidelink channel SC2 encompasses useful data of another type OTH, such as traffic-uncritical reminders, such as advertisements to the driver.

[0053] In another embodiment of steps 502 and 512 , the requirement for transmission is the size of the useful data N1 , the delay requirement and / or the desired reliability of the transmission.

[0054] In another embodiment of steps 502 and 512 , the request includes transmission on two channels SC2 and ADCH, whereby transmission safety is increased by redundancy.

[0055] In another embodiment of steps 502 and 512, the channel state information CSI2 of the self-organizing channel is used to determine the decision about providing on one of the channels ADCH, SC2. When the channel state information CSI2 indicates a high occupancy rate above a predetermined threshold, the provision is made for transmission on the sidelink channel SC2. For example, the number of roadside network units that can be reached directly via the self-organizing channel ADCH is higher than the threshold, so that a reliable distribution of the valid data P1 can only be ensured via the sidelink channel SC2. Correspondingly, when the threshold mentioned above is exceeded, the valid data P1 is provided according to steps 512 and 514 for transmission on the sidelink channel SC2.

[0056] In another embodiment of steps 502 and 512, the channel state information CSI1 of the sidelink channel is used to determine the decision on providing on one of the channels ADCH, SC2.

[0057] In another embodiment of steps 502 and 512, the channel state information CSI1 and CSI2 are used to determine the decision on providing on one of the channels ADCH, SC2.

[0058] In one embodiment of steps 502 and 512, when the size of the valid data N1 is lower than a predetermined threshold, the valid data N1 is provided to Figure 3 Advantageously, this allows for the transmission of small amounts of data in the unlicensed frequency range.

[0059] Figure 6 The schematic structure of a data packet MAC-FRAME according to IEEE 802.11 is shown and the interaction between blocks 310 and 318 is explained. The data packet MAC-FRAME consists of Figure 3 Block 318 in is created and is created by Figure 4 The block 318 in the data packet MAC-FRAME includes a data header H1, a frame body FB1 and a frame check sequence FCS.

[0060] The frame body part FB1 includes a data packet PDCP PDU, which includes a data header H2 and a data part D, which includes, for example, valid data. A network identifier K is arranged in the data header H2, which indicates to which protocol stack the corresponding data packet PDCP PDU is assigned, S-LTE-V, S-ITS-G5. Correspondingly, on the receiving side, in block 402, it is determined according to the network identifier K whether to provide the received frame body part FB1 to block 310 or to one of blocks 302 and 304. In an alternative embodiment not shown, the network identifier K is arranged in an optional parameter field of the data header H1.

[0061] Other aspects of this specification are found in the following clauses:

[0062] (Clause 1) A method for operating a road-side network unit, the method comprising: determining valid data for sending to at least one other road-side network unit; providing the valid data for sending on a side link channel within a licensed frequency range and / or for sending on a self-organizing channel within an unlicensed frequency range; and sending the valid data on the side link channel within the licensed frequency range and / or on the self-organizing channel within the unlicensed frequency range.

[0063] (Clause 2) A method according to clause 1, wherein the valid data is associated with a requirement for transmission, and wherein the providing is performed in accordance with the requirement for sending on the sidelink channel or for sending on the ad hoc channel.

[0064] (Clause 3) A method according to clause 2, wherein the requirement comprises a traffic class of valid data, in particular a traffic class according to ETSI TS102636-4-2 V1.1.1 (2013-10).

[0065] (Clause 4) A method according to any one of the above clauses, the method comprising: providing a first type of valid data for transmission on the self-organizing channel; and providing a second type of valid data for transmission on the sidelink channel.

[0066] (Clause 5) A method according to any one of the above clauses, wherein the requirements for transmission include the size and / or delay requirements of the valid data and / or the reliability of the transmission of the valid data.

[0067] (Clause 6) A method according to any of the preceding clauses, wherein local channel state information of the ad hoc channel is determined, and wherein the providing is performed based on the local channel state information.

[0068] (Clause 7) A method according to the preceding clause, wherein when the local channel state information indicates that the occupancy of the self-organizing channel is higher than a threshold, the valid data is provided for transmission on the sidelink channel.

[0069] (Clause 8) A method according to any one of the above clauses, wherein when the size of the valid data is lower than a threshold, the valid data is provided to the PDCP layer for transmission on the self-organizing channel.

[0070] (Clause 9) A method according to any of the preceding clauses, wherein the protocol stack according to ITS-G5 does not include protocol layers higher than layer 2, said protocol layers being allocated only to ITS-G5.

[0071] (Clause 10) A road side network unit, comprising: a processor for determining valid data for sending to at least one other road side network unit, and for providing the valid data for sending on a side link channel within a licensed frequency range and / or for sending on a self-organizing channel within an unlicensed frequency range; and two transceivers for a corresponding wireless communication network, for sending the valid data on the side link channel within the licensed frequency range and / or on the self-organizing channel within the unlicensed frequency range.

[0072] (Clause 11) The network unit according to clause 10, which is designed to implement the method according to one of clauses 1 to 9.

Claims

1. A method for operating a roadside network unit (UE1), the method comprising: - determining (302; 500; 512) valid data (N1, N2) for transmission to at least one other roadside network element (UE2; NE1), - providing (304; 504; 514) said valid data (N1, N2) for transmission on a sidelink channel (SC2) within a licensed frequency range (LFB) or for transmission on an ad hoc channel (ADCH) within an unlicensed frequency range (NLFB), and - transmitting (304; 508; 522) said valid data (N1, N2) on said sidelink channel (SC2) within said licensed frequency range (LFB) or on said ad hoc channel (ADCH) within said unlicensed frequency range (NLFB), wherein local channel state information (CSI2) of the self-organizing channel (ADCH) is determined, and wherein the providing (504; 514) is performed based on the local channel state information (CSI2), When the local channel state information (CSI2) indicates that the occupancy rate of the self-organizing channel (ADCH) is higher than a threshold, the valid data (N1, N2) is provided for transmission on the side link channel (SC2).

2. A method according to claim 1, wherein the valid data (N1, N2) is associated with a requirement for transmission, and wherein the providing (504; 514) is performed according to the requirement for sending on the side link channel (SC2) or for sending on the self-organizing channel (ADCH).

3. The method according to claim 2, wherein the requirement comprises the traffic class of the validity data (N1, N2). The method according to claim 3 , wherein the traffic class is a traffic class according to ETSI TS 102 636-4-2 V1.1.1 (2013-10).

5. The method according to any one of claims 1 to 4, comprising: -Provide (504) a first type (DENM; CAM) is used to send valid data (N1, N2) on the self-organizing channel (ADCH); and - providing (512) valid data (N1, N2) of a second type (OTH) for transmission on said sidelink channel (SC2).

6. The method according to any one of claims 2 to 4, wherein the requirements for transmission include the size and / or delay requirements of the valid data (N1, N2) and / or the reliability of the transmission of the valid data (N1, N2).

7. The method according to one of claims 1 to 4, wherein when the size of the valid data (N1, N2) is lower than a threshold, the valid data (N1, N2) is provided to the PDCP layer for transmission on the self-organizing channel (ADCH).

8. The method according to claim 1, wherein the protocol stack according to ITS-G5 (S-ITS-G5) does not include protocol layers higher than layer 2, which are only assigned to ITS-G5.

9. A roadside network unit (UE1), the roadside network unit comprising: - a processor for determining (302; 500; 512) valid data (N1, N2) for transmission to at least one other roadside network element (UE2; NE1) and for providing (304; 504; 514) said valid data (N1, N2) for transmission on a sidelink channel (SC2) within a licensed frequency range (LFB) or for transmission on an ad hoc channel (ADCH) within an unlicensed frequency range (NLFB); and - two transceivers (TA1, TC1) for a respective wireless communication network (CELL; VANET) for transmitting (304; 508; 522) said useful data (N1, N2) on said sidelink channel (SC2) within said licensed frequency range (LFB) or on said ad hoc channel (ADCH) within said unlicensed frequency range (NLFB), wherein local channel state information (CSI2) of the self-organizing channel (ADCH) is determined, and wherein the providing (504; 514) is performed based on the local channel state information (CSI2), When the local channel state information (CSI2) indicates that the occupancy rate of the self-organizing channel (ADCH) is higher than a threshold, the valid data (N1, N2) is provided for transmission on the side link channel (SC2). 10 . The network unit (UE1) according to claim 9 , which is designed to carry out the method according to one of claims 2 to 8 .

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