WO2020085550A1

WO2020085550A1 - V2x communication apparatus and shared channel access method therefor

Info

Publication number: WO2020085550A1
Application number: PCT/KR2018/012844
Authority: WO
Inventors: 김진우
Original assignee: 엘지전자 주식회사
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2020-04-30

Abstract

A shared channel access method for a V2X communication apparatus is disclosed. The shared channel access method for a V2X communication apparatus comprises the steps of: receiving, from an anchor channel, access information about a shared channel; constructing a local channel access map on the basis of the access information; and performing communication without accessing the shared channel when entering a collision-predicted area on the basis of the local channel access map, and while accessing the shared channel on the basis of the state of the shared channel when not entering collision-predicted area on the basis of the local channel access map.

Description

V2X communication device and its shared channel access method

The present invention relates to a V2X communication device and a method of accessing a shared channel thereof, and particularly, to simultaneously access a shared channel from the same memory to prevent collision between mediums and efficiently use resources.

In recent years, vehicles (vehicles) are becoming the result of complex industrial technologies in which electrical, electronic, and communication technologies are converged from the center of mechanical engineering. In this regard, vehicles are also called smart cars. Smart cars have connected to drivers, vehicles, and transportation infrastructure to provide a variety of user-specific mobility services as well as traditional vehicle technologies such as traffic safety / complexity cancellation. This connectivity can be implemented using V2X (Vehicle to Everything) communication technology.

In future transportation systems, vehicles (OBEs), road peripherals (RSEs), and non-vehicle participants around the road share their status and information acquired around them. Sharing of information is performed using V2X communication technology based on ad-hoc technology. V2X communication technology is evolving toward improving the efficiency of resource utilization from the viewpoint of the entire transportation system by optimizing not only safety-related purposes but also resource consumption (e.g., traffic congestion) occurring on the road.

With the diversification of technologies for V2X communication, there is an increasing need for access mediums based on independent technologies to share channels in the communication band for intelligent transport systems (ITS). Existing channel sharing technology largely uses static methods to separate medium access spatially or temporally according to predefined rules, and dynamic methods to use channels when channels are not occupied by detecting channel usage in real time. Includes.

In the method of statically dividing a channel, since all communication devices recognize and operate a predefined rule, the operation of different mediums is less likely to collide. However, even if a specific medium does not exist, the channel utilization may be lowered because the shared channel is accessed according to defined rules.

In the case of a method of dynamically dividing a channel, the communication device senses the use of the channel and approaches the empty channel, so that the channel utilization may be increased. However, due to the limitation of the unique operation of the medium based on independent technology, channel sharing cannot be used or a hidden node problem may occur. The Hidden Noe problem is an approach collision that occurs adjacent but out of coverage.

In order to solve the above technical problem, a shared channel access method of a V2X communication device according to an embodiment of the present invention comprises: receiving access information for a shared channel in an anchor channel; Constructing a local channel access map based on the access information; And when the collision prediction region is entered based on the local channel access map, the shared channel is not accessed, and when the collision prediction region is not entered based on the local channel access map, the sharing is based on the state of the shared channel. And accessing a channel and performing communication, wherein the anchor channel is a channel exclusively used by a medium supported by the V2X communication device, and the shared channel is a channel shared by a medium different from the medium.

In a shared channel access method of a V2X communication apparatus according to an embodiment of the present invention, the access information for the shared channel indicates shared channel identifier information for identifying the shared channel, and a medium used by a device accessing the shared channel Includes at least one of medium information to be performed, detected medium information indicating a medium sensed by a device accessing the shared channel, or device position and radius information indicating a location and a communication radius of a device accessing the shared channel do.

In the method of accessing a shared channel of a V2X communication device according to an embodiment of the present invention, the access information for the shared channel includes operating time information indicating a time when a device accessing the shared channel performs channel sensing, the It includes at least one of distribution condition information indicating whether redistribution of access information is performed, or measurement reliability information indicating reliability of a signal sensed by a device accessing the shared channel.

In a method of accessing a shared channel of a V2X communication device according to an embodiment of the present invention, the local channel access map includes the predicted collision area including points where the other medium is detected.

The shared channel access method of the V2X communication device according to an embodiment of the present invention further includes redistributing the access information when the access information is valid and satisfies the distribution condition of the access information.

In a method of accessing a shared channel of a V2X communication device according to an embodiment of the present invention, accessing the shared channel and performing communication based on the state of the shared channel includes: sensing a signal in the shared channel; And when the signal in the shared channel is not sensed, or when the signal in the shared channel is a signal of the same medium as the medium supported by the V2X communication device, performing the communication on the shared channel.

In addition, in order to solve the above technical problem, the V2X communication device according to an embodiment of the present invention, a memory for storing data; A communication unit that transmits and receives wireless signals; And a processor that controls the memory and the communication unit, wherein the processor receives access information for a shared channel in an anchor channel, configures a local channel access map based on the access information, and the local channel. When entering the collision prediction area based on the access map, the shared channel is not accessed, and when the collision prediction area is not entered based on the local channel access map, the shared channel is accessed based on the state of the shared channel. Communication is performed, and the anchor channel is a channel exclusively used by the medium supported by the V2X communication device, and the shared channel is a channel shared by the medium different from the medium.

According to the present invention, channels can be shared among devices using different mediums. In particular, by distributing access information on the shared channel in the anchor channel, collision in the shared channel can be recognized in advance and access to the shared channel can be prevented. Therefore, the channel use efficiency is increased, and collision between mediums of the shared channel can be reduced. In addition, by using a local channel map, even in the case of V2X communication of a device moving in a geographic space, collision in a shared channel can be effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to further understand the present invention and are incorporated in and constitute a part of this application, represent embodiments of the present invention together with detailed descriptions that explain the principles of the invention.

1 shows a reference architecture of an Intelligent Transport System (ITS) station according to an embodiment of the present invention.

2 shows a channel configuration according to an embodiment of the present invention.

3 shows hidden node problems that may occur in detection and avoidance operations.

4 and 5 illustrate a communication method in a shared channel of devices supporting different mediums according to an embodiment of the present invention.

6 illustrates an embodiment in which a device supporting a plurality of mediums participates in the above-described access information (re) distribution process.

7 shows a localized channel access map according to an embodiment of the present invention.

8 shows a local channel access map according to another embodiment of the present invention.

9 is a flowchart illustrating an operation of a device for entering a shared channel according to an embodiment of the present invention.

10 shows a configuration of a V2X communication device according to an embodiment of the present invention.

11 shows a shared channel access method of a V2X communication device according to an embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail, examples of which are shown in the accompanying drawings. The detailed description below with reference to the accompanying drawings is intended to describe preferred embodiments of the present invention rather than only those that can be implemented according to embodiments of the present invention. The following detailed description includes details to provide a thorough understanding of the present invention, but the present invention does not require all of these details. The present invention does not have to be used for each of the embodiments described below. Multiple embodiments or all embodiments may be used together, and specific embodiments may be used in combination.

Most of the terms used in the present invention are selected from general ones widely used in the art, but some terms are arbitrarily selected by the applicant and their meanings are described in detail in the following description as necessary. Therefore, the present invention should be understood based on the intended meaning of the term rather than the simple name or meaning of the term.

The present invention relates to a V2X communication device, the V2X communication device is included in the Intelligent Transport System (ITS) system, and may perform all or some functions of the ITS system. The V2X communication device can perform communication with a vehicle and a vehicle, a vehicle and an infrastructure, a vehicle and a bicycle, and a mobile device. The V2X communication device may also be abbreviated as a V2X device. As an embodiment, the V2X device may correspond to an Onboard Unit (OBU) of a vehicle, or may be included in the OBU. OBU may also be referred to as OBE (On Board Equipment). The V2X device may correspond to an infrastructure roadside unit (RSU) or may be included in the RSU. RSU may also be referred to as RSE (RoadSide Equipment). Alternatively, the V2X communication device may correspond to the ITS station or may be included in the ITS station. Any OBU, RSU, and mobile equipment that performs V2X communication may be referred to as an ITS station or a V2X communication device.

In the architecture of FIG. 1, two end-of-vehicle / users can communicate the communication network, and such communication can be performed through the functionality of each layer of the architecture of FIG. For example, when a vehicle-to-vehicle message is communicated, data is transmitted through each layer down one layer in the transmitting vehicle and its ITS system, and data is passed through each layer up one layer in the receiving vehicle and its ITS system. Can be delivered. Description of each layer of the architecture of Figure 1 is as follows.

Application layer: The application layer can implement and support various use cases. For example, the application may provide road safety, efficient traffic information, and other application information.

Facility layer: The facility layer can support to effectively realize various use cases defined in the application layer. For example, the facility layer may perform application support, information support, and session / communication support.

Networking & Transport Layer: The network / transport layer can configure a network for vehicle communication between homogenous / heterogeneous networks by using various transport protocols and network protocols. For example, the network / transport layer can provide Internet access and routing using Internet protocols such as TCP / UDP + IPv6. Alternatively, the network / transport layer may configure a vehicle network using a geographical position-based protocol such as Basic Transport Protocol (BTP) / GeoNetworking.

Access layer: The access layer may transmit the message / data received from the upper layer through a physical channel. For example, the access layer includes a communication technology based on IEEE 802.11 and / or 802.11p standards, a ITS-G5 wireless communication technology based on the physical transport technology of IEEE 802.11 and / or 802.11p standards, and a satellite / wideband wireless mobile communication. It can perform / support data communication based on 2G / 3G / 4G (LTE) / 5G wireless cellular communication technology, broadband terrestrial digital broadcasting technology such as DVB-T / T2 / ATSC, GPS technology, IEEE 1609 WAVE technology, and so on.

The ITS architecture may further include a management layer and a security layer.

In this specification, V2X communication devices performing V2X communication may be referred to as a V2X device, an ITS station, a station, a device, and the like.

2 shows a frequency channel configuration shared by three access mediums (Medium X, Medium Y, and Medium Z). Referring to FIG. 2, the principle of detection and avoidance, which is a dynamic channel sharing method, will be described.

Each access medium is assigned an anchor channel with channel access guaranteed by default. In the embodiment of FIG. 2, A channels, B channels, and C channels correspond to medium X, medium Y, and medium Z anchor channels, respectively. In principle, access to other mediums to the anchor channel assigned for that medium is excluded, unless the use of that medium in that frequency band is completely excluded.

The K channel, the L channel, and the M channel correspond to a shared channel that can be used by multiple access mediums. For example, the L channel can be used by each medium in a condition that medium X, medium Y, and medium Z do not collide with each other. Since the channel is not shared and used under a predefined rule, a communication device using medium X senses a signal from a communication device using another medium for the channel before attempting to access the channel. If medium Y or medium Z already occupies and uses the L channel, a communication device using medium X may use channel A first. The communication device periodically senses the shared channel and may use the shared channel when it is determined that other medium is not using the channel.

In the present invention and specification, medium / access medium may refer to channel access technology. As an embodiment, the medium is ITS-G5 or Dedicated Short-range Communication (DSRC) / Wireless Access for Vehicle Environment (DSRC) wireless communication technology based on IEEE 802.11 and / or 802.11p standard physical transmission technology, satellite / wideband wireless 2G / 3G / 4G (LTE) / 5G wireless cellular communication technology including mobile communication, broadband terrestrial digital broadcasting technology such as DVB-T / T2 / ATSC, and access technology such as GPS technology.

In the following specification, additional operations are described based on the frequency channel configuration of FIG. 2.

In FIG. 3, device 1 (device # 1) operating in the same channel uses medium X, and device 2 (device # 2) uses medium Y. In this case, device 1 does not recognize device 3 outside of coverage, and device 3 does not recognize device 1 outside of coverage. Therefore, the device 1 and the device 3 can determine that they can occupy the channel and perform communication using their own medium. In this case, device 2 cannot communicate with both device 1 and device 3 due to collision between mediums.

The collision between mediums may be further exacerbated by the medium's unique operating characteristics. For example, when the LTE-V2X device and the 802.11p-based DSRC / WAVE device perform V2X communication through a shared channel in an adjacent area, the LTE-V2X device detects the access of another medium during operation and detects access to its channel. The reservation operation is not performed. Therefore, a collision may occur when accessing a channel between two mediums. In addition, while the area where other LTE-V2X devices in the vicinity operate as LTE-V2X continues to expand, the chance of channel access is significantly reduced in the surrounding 802.11p-based DSRC / WAVE devices due to the Listen Before Talk (LBE) operation. You can.

Hereinafter, an approach for recognizing channel usage effectively when a plurality of V2X access mediums use a shared channel together with a detection-and-avoidance principle will be described. The V2X access medium corresponds to access technologies such as DSRC / WAVE, C-V2X, LTE-V2X, and 802.11I, or can use such access technology.

When a plurality of mediums dynamically use a shared channel through the detection-and-avoidance principle, communication devices may propagate access information for the shared channel in an anchor channel for the medium they support. Therefore, a communication device that wants to use a specific shared channel can obtain access information on the shared channel from an anchor channel for a medium that it supports. If a device that wants to use a specific shared channel does not acquire access information for the shared channel in an anchor channel of a medium it supports, it must perform a signal detection and decoding process (signal sensing) in the shared channel.

4 and 5, when devices supporting different mediums perform V2X communication on one shared channel, when a specific device encounters a device supporting itself and another medium, information about the device is distributed through an anchor channel. , Indicates a process corresponding to other devices based on this information.

4 illustrates operation of communication devices before distribution of access information according to an embodiment of the present invention.

4 and 5, devices S1 to S6 support / use medium X, and devices T1 to T6 support / use medium Y. Since the device S3 and the device T4 are located adjacently, the device S3 and the device T4 can sense that different mediums are used in the channel M. Device S3 and device T4 generate access information for channel M, each of which sets an area where motion of another medium is expected to be a “collision expected area” of the channel M based on their location, and distributes the information in its anchor channel. You can.

5 illustrates operation of communication devices after distribution of access information according to an embodiment of the present invention.

The device S3 and the device T4 stop using the channel M with the distribution of the access information of the channel M. Among devices (S1, S2, S4, S5, and S6) that have received access information of channel M in channel A, devices that satisfy the distribution conditions included in the access information (for example, S2, S4, S5) Redistribute access information. Among devices (S1, S2, S4, S5, and S6) that have received access information of channel M in channel A, devices that do not satisfy the distribution condition included in the access information (eg, S1, S6) are accessed Stop redistribution of information.

Among devices (T1, T2, T3, T5, and T6) that have received access information of channel M in channel B, devices that satisfy the distribution conditions included in the access information (for example, T2, T3, T5) Redistribute access information. Among devices (T1, T2, T3, T5, and T6) that have received access information of channel M in channel B, devices (T1, T6) that do not satisfy the distribution conditions included in the access information may redistribute the access information. Stop.

Among devices that have received access information for channel M, devices (S1, S2, T5, and T6) that used channel M determine whether they are included in the collision prediction area from the access information, and within the collision prediction area Devices S2 and T5 can immediately stop using channel M.

Since access information on the shared channel is continuously redistributed by neighboring devices by default after being distributed to the anchor channel, other devices approaching the predicted collision area in the future also recognize the situation in advance and avoid access to the shared channel. can do. Devices located within the anticipated collision zone of channel M can immediately stop using channel M and communicate through each medium's anchor channel and other shared channels. However, even these devices can sense channel M.

Due to the difference in characteristics of each medium, the detection range P of the device S3 and the detection range Q of the device T4 may be different, and thus, per anchor channel, recognition of a collision prediction region for a shared channel may be different. . Therefore, when setting the actual collision prediction area from the access information, the device may consider a predefined margin in consideration of the medium communication range.

An operation in which a device operating in an anchor channel distributes information about a specific shared channel in an anchor channel can be triggered by the following three conditions. The process of accessing the medium X, which is a device supporting the medium X, to the channel M will be described as an example.

1) When a device supporting medium X detects a medium other than medium X in channel M, the device may generate access information. When determining that a device supporting Medium X detects another medium, two cases are included. First, although a signal larger than a certain level is detected by the energy detection operation in the channel M, the signal may be decoded using medium X, but a part of the signal may not be decoded. In addition, there is a case in which an output of a certain level or more is detected by performing correlation between a known signal (reference signal) used by another medium and a received signal.

2) If a device supporting medium X does not detect any medium signal on channel M, and the user wants to use the channel as medium X, the device may generate access information.

3) When a device supporting medium X receives access information for channel M on channel A (anchor channel of medium X) and is located in the device location and 'the same position within the error range' in the access information , The device can regenerate or update the access information after sensing on channel M. Due to the device characteristics of the moving V2X communication environment, channel sensing cannot always be performed in the same location as where the previous channel sensing was performed. Therefore, "the same position in the error range" means that it is assumed that sensing at the corresponding position is sensed at the same position if the position is within the margin, rather than as an error, which is a position directly comparable to the past sensing range.

The access information distributed in the anchor channel by the above conditions can be redistributed under the following conditions.

1) When a device operating in channel A (anchor channel of medium X) acquires access information of channel M in channel A and distribution conditions in the access information are valid, the device redistributes the access information.

2) When a device supporting medium X and medium Y acquires access information of channel M on channel A (anchor channel of medium X), and the distribution condition in the access information is valid, the device transmits access information to channel B ( Medium Y's anchor channel).

The device may perform redistribution by redistributing the access information received from one device as it is. In addition, the device may perform redistribution by combining and redistributing information received from a plurality of devices within a valid distribution condition. Distribution conditions in the access information will be described again below.

The access information on the shared channel distributed in the anchor channel may include at least one of the following information.

Shared channel identifier information: When there are multiple shared channels in the V2X communication band, the shared channel identifier information may indicate an ID for distinguishing each shared channel. For example, channel numbers such as 172 and 176 may be used as shared channel identifier information.

Operating medium information: indicates the medium used by the device accessing the shared channel. For example, access mediums such as 802.11p, LTE-V2X, and NR-V2X can be indicated. As an embodiment, an ad-hoc communication medium and a cellular communication medium may be indicated. The ad hoc communication medium may include 802.11, ITS-G5 or DSRC / WAVE technology, and the cellular communication medium may include LTE-V2X, NR-V2X communication technology.

Detected medium information: indicates a medium sensed by a device accessing a shared channel. When it is not possible to distinguish which medium, it may be displayed as "unknown medium" or "none" if no signal is detected at all.

Device location and range information: This information can be used to recognize the medium's regional distribution and expected collision range in the shared channel described above. As an embodiment, the longest radius (m) and the minimum radius (m) of the latitude and longitude coordinates and the ellipse may be indicated. Based on the detected medium information, this information may be determined as one of: a) information indicating a location and a communication radius of a device operating in a shared channel, or b) a location and a communication radius information of a device detecting another medium in the shared channel. You can. When the medium indicated by the motion medium information and the detected medium information are the same, the information of a) is used, and when the motion medium information and the medium indicated by the detected medium information are different, the information of b) may be used. The communication radius may mean the maximum communication radius that the signal reaches. In the case of an unknown medium, it may be designated as a maximum value of a communication radius of each medium supported in the ITS band.

Operating time information: This information indicates when the device occupies or performs channel sensing in the shared channel, and the validity of the access information can be determined based on the time. That is, when access information having different operating times is distributed in the "same location within the error range", it may mean that the latest information has been updated from the past information in time. As an embodiment, the operation time information may be indicated in Universal Time Coordinated (UTC) reference time or Greenwich Mean Time (GMT) reference time format.

Distribution contidion information: This information indicates a reference condition for determining whether to redistribute peripheral devices for access information received from the anchor channel. This information is used to prevent message flooding due to distribution of access information in each anchor channel and to deliver only valid information. As an embodiment, the distribution condition information may include time limit information (relative time versus operating time), space limit information (relative range of latitude and longitude axes relative to davias position and range information), or redistributable devices within unit space. It may include at least one of the number information.

Measurement reliability information: indicates the reliability of a signal sensed by a device that detects another medium. This information may be used to determine the validity of the access information to be used to set a collision expectation area among the plurality of access information generated in the "same location within the error range". Expected collision areas will be described later.

In FIG. 6, devices S2 and T5 are devices that support both medium X and medium Y. Since these devices can communicate in channel A and channel B, when access information for channel M is distributed in one channel, access information received in another channel can be redistributed.

In FIG. 6, the time difference that may occur when the device S3 and the device S4 recognize each other and distribute access information is not mentioned, but in a real communication environment, the time difference is due to a difference in operating characteristics unique to the medium, such as a difference in sensing range per medium. May occur. Therefore, when a device supporting a plurality of mediums is adjacent to an area where collision is expected to participate in distribution of access information, pre-collision avoidance of peripheral devices can be more efficiently operated.

Hereinafter, a method of configuring a channel access map for each device using the above-described access information will be described.

As described above, a device operating in an anchor channel may redistribute by combining access information for a specific shared channel distributed in the vicinity. Based on the collected access information, the device can configure a channel access map for the shared channel.

7 shows an embodiment of a channel access map configured by a device that supports / uses Medium X. The channel access map may display channel usage information or channel sensing information collected from access information on a map including a general road and building area. In FIG. 7, A1 to A9 denote points where the device has accessed V2X communication by accessing channel M, and A10 to A17 are points where other medium (medium Y or medium Z) is sensed in the channel sensing step.

As described above, the location where the other medium is detected may be displayed with a larger radius than the case where the medium X uses a shared channel by compensating for a sensing operation characteristic between the medium, a difference in the location of the sensing device and the actual operating device. . Compensation of the difference between the position of the sensing device and the position of the actual operating device may be performed by adding a range margin to the sensing position.

The range margin may be set in advance in consideration of sensing characteristics of each medium and position differences between the sensing device and the operating device. A new point may be added to each point of the local channel map through sensing of channel M. In addition, each point of the local channel map may expire and expire under the distribution condition on the access information. The local channel map may change its display by updating the access information itself. The local channel map may be updated or displayed due to the access information itself being changed from an ego medium to another medium, or vice versa.

In FIG. 7, a region inside the dotted line may be set as a collision prediction area of medium X by linearly connecting points where other mediums are detected on the local channel access map. The expected collision region may be a region where V2X communication is not allowed to devices supporting only medium X on channel M. Therefore, through access information distributed in the anchor channel (channel A), each device can configure a local channel access map for channel M and recognize the collision prediction region in advance. Therefore, even in a channel environment in which different mediums coexist, V2X communication can continue without collision.

In the map of FIG. 7, points AI2 and AI13 overlap the display radius, which is because the point AI13 that detects other medium is displayed wider in consideration of the range margin than the actual one, so that it overlaps with AI3 using the channel as the actual magnetic medium. In this case, AI3 marked as self-medium use is considered as accurate information, and the overlapping part may be excluded from the collision prediction area.

As described above, due to changes in access information and distribution conditions newly received in the surroundings, display contents of the "local channel access map" possessed by each device may be dynamically changed over time.

FIG. 8 shows a device operating in another anchor channel (channel B or channel C) in the environment as shown in FIG. 7 by participating in redistribution of access information by a device supporting a plurality of mediums (medium X and medium Y). This is an example of a local channel access map for channel M that can be done. A device supporting a plurality of mediums may collect and distribute access information (AI1 to AI17) capable of constructing a channel map as shown in FIG. 7 in channel A. In channel B, the device may distribute access information of channels M (AI18 to AI23) from devices operating in medium Y. In FIG. 8, it is assumed that access information using medium Y is recognized only for the lower right of FIG. 8.

The device operating in channel B may configure a local channel access map different from FIG. 8 through access information on channel M collected using medium X and medium Y. The additionally generated information may recognize a point classified as an unknown medium in FIG. 7 as a known medium in some cases. For example, the unannounced medium AI15 of FIG. 7 is determined to be “the same position within the error range” as AI20 in FIG. 8, and may be recognized as an area where medium Y is used. In FIG. 7, the unannounced medium AI13 and the unannounced medium AI18 of FIG. 8 have few overlapping parts to determine as “the same position within the error range”, and AI13 may be included as a collision prediction area. In FIG. 8, an area inside the dotted line may be set as a collision prediction area of a device supporting MIDI ohm Y.

The expected area of collision for a particular medium that is virtually obtained from the local channel access map is the minimum area where the medium should evade the V2X channel in that shared channel. Devices attempting V2X communication in the vicinity of the collision prediction area should start channel sensing in advance at a certain distance margin in the collision prediction area.

The device may perform pre-setting for access to the shared channel (S9010). The device may check anchor channel and shared channel allocation information of a band where V2X communication is permitted, and select a shared channel to be used.

The device may search for access information in the anchor channel (S9020). The device may collect access information for the corresponding shared channel in the anchor channel. Access information may be received in a beacon message or event message in V2X communication.

The device may acquire access information (S9030), and check whether the access information is valid (S9040). When the device receives the message including the access information, it can first determine whether the access information is valid. The device accesses when the measurement reliability of the received access information is higher than the measurement reliability of other access information distributed in an adjacent place, or when the operating time of the received access information is more recent than the operation time of other access information distributed in an adjacent place. You can decide that the information is valid. If the sensing location included in the received access information and the device's own location do not correspond to the "same location within the error range", the device assumes that the received access information is invalid and senses the signal directly from the shared channel to generate new access information Can be created and distributed.

If the received access information is valid, the device may redistribute the access information (S9050). The device may redistribute the access information when the received access information is valid and the distribution conditions of the access information are satisfied. When one or more different access information is received from different devices in the vicinity, the device may merge and redistribute the received access information.

The device may configure a local channel access map and calculate an estimated collision area (S9060). The device may generate a local channel map based on the received access information. As described above, the device may calculate a collision budget area for a corresponding shared channel based on overlap or type between access information.

When the device enters the collision prediction area (S9070), the device may avoid using the corresponding shared channel or perform V2X communication through another available channel (S9080). If the device decides that the current self (ego-device) location is located in the expected collision area, it stops the V2X communication attempt on the shared channel and the anchor channel or starvation available channel (such as other previously secured shared channels). Can perform V2X communication.

If the access information is not obtained (S9030), the access information is invalid (S9040), or does not enter the expected collision area (S9070), the device may sense a signal by entering a corresponding shared channel (S9090).

When a signal is sensed / sensed in a shared channel (S9100), the device may detect whether the signal is a medium signal supported (S9110). As an embodiment, checking whether or not the medium signal is supported may be confirmed when there is no error in the error detection code by performing decoding after synchronizing the signals and extracting data.

When a signal is detected in the shared channel (S9100), and the corresponding signal is a signal of a different medium / media (S9110). The device may perform V2X communication on the corresponding shared channel (S9130).

When a signal is detected in the shared channel (S9100), and the corresponding signal is a signal of a different medium / media (S9110), the device may distribute access information in the anchor channel (S9120).

If a signal is not detected in the shared channel (S9100), or the detected signal is not a signal of another medium / media (S9110), the device may perform V2X communication in the corresponding shared channel (S9130).

Although not represented in the flow chart, in a situation where the device continuously moves, such as V2X communication, in order to occupy the shared channel while avoiding collisions between mediums, the next time for the shared channel during V2X communication within the shared channel as well as when entering the first shared channel The process must continue. First, the local channel access map and the expected collision zone settings must be continuously updated. In addition, the device must continuously check whether its current location has entered the predicted collision memory. In addition, the device should perform direct sensing in a shared channel if necessary.

Described is a channel sensing method of an LTE-V2X device using a shared channel. All LTE-V2X devices operating on one shared channel reserve the same resource that does not overlap with any TX-pools allocated for V2X communication for channel sensing. This is to establish a silence period in the channel that does not overlap with any TX-pool operating in a specific region. In the region, signal transmission for LTE-V2X communication between LTE-V2X devices is not allowed in the silence period for channel sensing. Therefore, the channel usage of different medium can be detected from the value of the received signal strength indicator (RSSI) measured in this period. In this preset silence period, known data such as various reference signals may be transmitted or included. The arrangement of this silence period within the LTE frame may be different for each shared channel.

In FIG. 10, the V2X communication device 10000 may include a communication unit 10010, a processor 10020, and a memory 10030.

The communication unit 10010 is connected to the processor 10020 to transmit / receive wireless signals. The communication unit 10010 may upconvert data received from the processor 10020 into a transmission / reception band to transmit a signal or downconvert a received signal. The communication unit 10010 may implement an operation of at least one of a physical layer or an access layer.

The communication unit 10010 may include a plurality of sub RF units to communicate according to a plurality of communication protocols. As an embodiment, the communication unit 10010 is ITS-G5 or Dedicated Short-range Communication (DSRC) / Wireless Access for Vehicle Environment (WAVE) wireless communication technology based on the physical transmission technology of the IEEE 802.11 and / or 802.11p standard. Data communication can be performed based on 2G / 3G / 4G (LTE) / 5G wireless cellular communication technology including satellite / wideband wireless mobile communication, broadband terrestrial digital broadcasting technology such as DVB-T / T2 / ATSC, GPS technology, etc. have. The communication unit 10010 may include a plurality of transceivers implementing each communication technology. In addition, one of the plurality of transceivers may access the control channel, and the other transceiver may access the service channel.

The processor 10020 may be connected to the communication unit 10010 to implement operations of layers according to the ITS system or RSRC / WAVE system. The processor 10020 may be configured to perform operations according to various embodiments of the present invention according to the above-described drawings and descriptions. In addition, at least one of modules, data, programs, or software implementing the operation of the V2X communication device 10000 according to various embodiments of the present invention described above is stored in the memory 10030 and can be executed by the processor 10020. have.

The memory 10030 is connected to the processor 10020, and stores various information for driving the processor 10020. The memory 10030 may be included inside the processor 10020 or installed outside the processor 10020 to be connected to the processor 10020 by known means.

As an embodiment, ITS-G5 or Dedicated short-range communication (DSRC) / Wireless Access for Vehicle Environment (DSRC) wireless communication technology based on the above-described IEEE 802.11 and / or 802.11p standard physical transmission technology, satellite / wideband wireless 2G / 3G / 4G (LTE) / 5G wireless cellular communication technology including mobile communication, broadband terrestrial digital broadcasting technology such as DVB-T / T2 / ATSC, GPS technology, may correspond to the above-described medium. The communication unit 10010 may include at least one transceiver that implements each medium. And, one of the plurality of transceivers can access the channel based on the medium used / supported.

The processor 10020 of the V2X communication device 10000 may perform the channel sharing operation described in the present invention. The channel sharing operation of the V2X communication device 10000 will be described below.

In addition to the steps in FIG. 11, the detailed steps described in FIG. 9 can be performed.

The V2X communication device may receive access information for the shared channel (S11010). The V2X communication device may receive a message including access information in the anchor channel, and obtain access information from the message.

The V2X communication device may configure a local channel map based on the access information (S11020). The local channel map may be configured as in the above-described embodiments in FIGS. 7 and 8. The local channel map may include or indicate an area of collision prediction that includes points where other mediums are detected.

The V2X communication device may avoid the shared channel based on the local channel map, or access and communicate with the shared channel based on the local channel map (S11030). The V2X communication device may not access the shared channel when entering the collision prediction area. The V2X communication device may access and communicate with the shared channel based on the state of the shared channel when the collision prediction is not entered.

As described above, the anchor channel is a channel exclusively used by a medium supported or used by the V2X communication device, and the shared channel is a channel shared by a medium different from the medium supported or used by the V2X communication device.

As described above, the access information for the shared channel indicates shared channel identifier information for identifying the shared channel, operation medium information indicating the medium used by the device accessing the shared channel, and medium sensed by the device accessing the shared channel. It may include at least one of the detected medium information, or device location and radius information indicating the location and communication radius of the device accessing the shared channel. The device may point to another V2X communication device or a vehicle including the V2X communication device.

As described above, the access information for the shared channel is access time information indicating whether the device accessing the shared channel performs channel sensing, distribution condition information indicating whether to redistribute access information, or access to the shared channel. The device may include at least one of measurement reliability information indicating reliability of a signal sensed by a device.

The above-described method for accessing the shared channel of the V2X communication device may further include redistributing the access information when the access information is valid and the redistribution conditions of the access information are satisfied.

In the above-described method for accessing a shared channel of a V2X communication device, accessing a shared channel and performing communication based on a state of the shared channel includes: sensing a signal in the shared channel; And when the signal in the shared channel is not sensed or the signal in the shared channel is a signal of the same medium as the medium supported by the V2X communication device, the method may further include performing communication on the shared channel.

The embodiments described above are those in which the components and features of the present invention are combined in a predetermined form. Each component or feature should be considered optional unless stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to configure an embodiment of the present invention by combining some components and / or features. The order of the operations described in the embodiments of the present invention can be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is apparent that claims that do not have an explicit citation relationship in the claims can be combined to constitute an embodiment or included as a new claim by amendment after filing.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. For implementation by hardware, one embodiment of the invention includes one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code can be stored in memory and driven by a processor. The memory is located inside or outside the processor, and can exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential features of the present invention. Therefore, the above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

It is understood by those skilled in the art that various changes and modifications are possible in the present invention without departing from the spirit or scope of the present invention. Accordingly, the present invention is intended to cover modifications and variations of the invention provided within the scope of the appended claims and their equivalents.

In this specification, both the device and method inventions are mentioned, and the descriptions of both the device and method inventions can be applied to complement each other.

Various embodiments have been described in the best mode for practicing the present invention.

The present invention is used in a series of vehicle communication fields.

It is apparent to those skilled in the art that various changes and modifications are possible in the present invention without departing from the spirit or scope of the present invention. Accordingly, the present invention is intended to cover modifications and variations of the invention provided within the scope of the appended claims and their equivalents.

Claims

Receiving access information for a shared channel in an anchor channel;

Constructing a local channel access map based on the access information; And

If the collision prediction area is entered based on the local channel access map, the shared channel is not accessed, and if the collision prediction area is not entered based on the local channel access map, the shared channel is based on the state of the shared channel. A method of accessing a shared channel of a V2X communication device, comprising: accessing and performing communication,

The anchor channel is a channel exclusively used by a medium supported by the V2X communication device, and the shared channel is a channel shared by a medium different from the medium.
The method of claim 1

The access information for the shared channel indicates shared channel identifier information for identifying the shared channel, operation medium information indicating a medium used by a device accessing the shared channel, and medium detected by a device accessing the shared channel. And at least one of detected medium information or device location and radius information indicating a location and a communication radius of a device accessing the shared channel.
According to claim 2,

The access information for the shared channel may include operating time information indicating when a device accessing the shared channel performs channel sensing, distribution condition information indicating whether redistribution of the access information is performed, or the shared channel. And at least one of measurement reliability information indicating reliability of the signal sensed by the accessed device.
According to claim 1,

The local channel access map includes the predicted collision area including the points where the other medium is detected.
According to claim 1,

And redistributing the access information if the access information is valid and the distribution conditions of the access information are satisfied.
According to claim 1,

The step of accessing and communicating with the shared channel based on the state of the shared channel includes:

Sensing a signal in the shared channel; And

If the signal in the shared channel is not sensed, or the signal in the shared channel is a signal of the same medium as the medium supported by the V2X communication device, further comprising performing the communication in the shared channel, the shared channel Approach.
In the V2X communication device,

A memory for storing data;

A communication unit that transmits and receives wireless signals; And

And a processor that controls the memory and the communication unit,

The processor,

The anchor channel receives access information for the shared channel,

Construct a local channel access map based on the access information, and

If the collision prediction area is entered based on the local channel access map, the shared channel is not accessed, and if the collision prediction area is not entered based on the local channel access map, the shared channel is based on the state of the shared channel. Access, conduct communication,

The anchor channel is a channel exclusively used by a medium supported by the V2X communication device, and the shared channel is a channel shared by a medium different from the medium.
The method of claim 7,

The access information for the shared channel indicates shared channel identifier information for identifying the shared channel, operation medium information indicating a medium used by a device accessing the shared channel, and medium detected by a device accessing the shared channel. And at least one of detected medium information or device location and radius information indicating a location and a communication radius of a device accessing the shared channel.
The method of claim 8,

The access information for the shared channel may include operating time information indicating when a device accessing the shared channel performs channel sensing, distribution condition information indicating whether redistribution of the access information is performed, or the shared channel. A V2X communication apparatus including at least one of measurement reliability information indicating reliability of a signal sensed by an accessed device.
The method of claim 7,

The local channel access map includes the predicted collision area including the points where the other medium is detected, V2X communication device.
The method of claim 7,

The processor redistributes the access information when the access information is valid and satisfies the distribution condition of the access information, V2X communication device.
The method of claim 7,

The operation of accessing and communicating with the shared channel based on the state of the shared channel of the processor is performed.

Sensing a signal in the shared channel; And

If the signal is not sensed in the shared channel, or the signal in the shared channel is a signal of the same medium as the medium supported by the V2X communication device, it is performed by performing the communication in the shared channel, V2X communication device.