KR101237951B1 - System for controlling arp time in vehicle to infrastructure network - Google Patents

Abstract

PURPOSE: An ARP(Address Resolution Protocol) time control system on a V2I(Vehicle to Infrastructure) network is provided to control ARP time for a vehicle terminal from an RSU(Road-Side Unit) by using VCD(Vehicle Communications Device) status information. CONSTITUTION: If the average ARP time of a neighboring RSU is determined to be less than the standard ARP time, an RSU calculates ARP time by using VCD status information(S551). The RSU determines whether the ARP time for the VCD is less than the standard ARP time(S560). If the ARP time for the VCD is less than the standard ARP time, the RSU applies the new calculated ARP time(S561). The RSU performs a broadcasting process to the VCD(S570).

Description

System for Controlling ARP Time In Vehicle TO Infrastructure Network

The present invention relates to an ARP time control system in a V2I network. More specifically, the present invention relates to an ARP time control system in a V2I network that controls Address Resolution Protocol (ARP) time for a vehicle communication device (VCD) in a vehicle side station (RSU).

With the advent of the ubiquitous era, the requirement to access desired services anytime, anywhere has been extended to driving vehicles, and in particular, getting information necessary for safe driving in real time has become an important issue. Therefore, information about the speed, location, braking, driving status, and road conditions of vehicles in a region directly or indirectly connected to surrounding vehicles while driving from a driver's point of view is provided through a vehicle equipped with a vehicle terminal, a vehicle base station, or a vehicle and a vehicle. Research on V2I (V2I: Vehicle to Infrastructure) / V2V (V2V: Vehicle to Vehicle) communication-based services and technical research on vehicle safety services are provided to enable smooth and safe traffic flow between vehicles. There is.

V2I communication technology is a technology that provides communication between a vehicle and a road side unit (RSU) to support ITS (Intelligent Transport Systems) service or Internet service. In particular, it is a wireless transmission technology that can support up to 54Mbps for vehicles running at speeds up to 200km / h. In the V2I based on WAVE (WAVE: Wireless Access In Vehicle Environment) introduced in consideration of the characteristics of the vehicle network, the control channel (CCH) It provides various services from vehicle base station to vehicle using Control Channel) and Service Channel (SCH).

1 is a schematic conceptual diagram of a general WAVE communication system.

Referring to FIG. 1, a WAVE communication system includes a vehicle base station (RSU: Road Side Unit) 111, a vehicle base station router (MC: Middle Network Controller) 130, and a vehicle terminal mounted on a vehicle 150 (VCD: Vehicle). Communication device).

2 is a flowchart illustrating a connection process between a conventional vehicle terminal and a vehicle base station.

Referring to FIG. 2, when the vehicle terminal 153 receives a broadcasting message from the vehicle base station 111, the vehicle terminal 153 searches for a channel state (S210) and transmits its MAC (Media Access Control) to the vehicle base station 111. Send request for authentication and connection request (S220, S230). Here, the authentication request process can be omitted.

Subsequently, the vehicle terminal 153 requests the IP allocation by sending a DHCP DISCOVER message to the vehicle base station 111 (S240), and the vehicle base station 111 allocates the IP of the vehicle terminal 153 and uses the DHCP offer. Inform 153 that IP allocation is possible.

Subsequently, the vehicle terminal 153 sends a DHCP Request message to the vehicle base station 111 (S250) and receives a DHCP Ack message from the vehicle base station 111.

Subsequently, the vehicle terminal 153 sends an address resolution protocol (ARP) Query message to the vehicle base station 111 (S260), receives an IP to be allocated from the vehicle base station 111, and receives IP and MAC information of vehicle terminals located in the neighborhood. do.

Subsequently, the vehicle terminal 153 requests the PING THROUGH to the vehicle base station 111 (S270), and when the response to the PING THROUGH is received from the vehicle base station 111, the vehicle terminal 153 connects with the vehicle base station 111. After (S280) data communication with the vehicle base station 111 is enabled by TCP.

That is, while the above process is performed, the vehicle terminal 153 cannot request individual information to the vehicle base station 111, and if it is calculated as time, data communication with the vehicle base station 111 may be possible after about 400 ms. do. At this time, the vehicle terminal 153 is connected in a state of about 81-87m until the first data transmission and reception after the signal of the vehicle base station 111 is searched.

3 is a diagram illustrating a request time for each connection process between a conventional vehicle terminal and a vehicle base station.

Referring to FIG. 3, the authentication request and the connection request process take 70 ms and occupy about 21% of the 336 ms time required for the whole process.

In addition, the most required process in the connection process between the vehicle terminal and the vehicle base station is a DHCP disconnection time (DHCP disconnection, DHCP request) at the vehicle base station 111, and then the ARP delivery and update time (ARP Query). have. In this case, the DHCP allocation may be represented by two methods of renewing the wire-based DHCP renewal time in units of 10 minutes and renewing in units of 60 seconds. If the renewal time of the DHCP is generated every 60 seconds, the DHCP updates the information included in the ARP table generated separately by the vehicle base station 111, the update time of the ARP Query is 60 seconds. That is, the vehicle base station 111 updates the ARP in accordance with the minimum renewal time of the DHCP.

Here, the following problem occurs during the IP communication transfer process between the vehicle base station 111 and the vehicle terminal 153.

First, when the vehicle terminal 153 moves faster than the ARP Query update time, a problem occurs when the vehicle base station 111 allocates an IP to the vehicle terminal 153. That is, both the vehicle base station 111 and the neighboring vehicle base station 113 adjacent to the vehicle base station 111 have information of the vehicle terminal 153. Here, when requesting data from the vehicle base station 111 and the neighboring vehicle base station 113 or the vehicle terminal 153 or when it is determined that an error occurs, the vehicle terminal 153 attempts to connect to both vehicle base stations 111 and 113. In this process, unnecessary network traffic occurs.

Second, if the ARP Query update is frequent, eventually the renewal time of DHCP or ARP Query increases, which puts a heavy load on the network. For example, data transmission and reception time is about 55 seconds at 100km per hour, but since not all vehicles travel at 100km per hour, the speed of the vehicle is very variable according to traffic conditions. Therefore, a problem arises in that the variability of the ARP Query update time is required.

In addition, problems occur in the ARP time even when the vehicle moves at a low speed. For example, the vehicle terminal 153 moving below 20 km per hour may travel from 5 minutes to several hours in one cell serviced by the vehicle base station 111. In this case, 50 to 150 vehicles may request a service in one cell, and frequent IP update and allocation may act as an overhead other than data communication.

That is, assuming that about 150 vehicles exist in the service cell of the vehicle base station 111 and move at 20 km / h for each individual vehicle, and the ARP Query is updated every 60 seconds, IP is allocated during the entire data communication time of a single vehicle. The ARP Query update time of the vehicle base station 111 for occupies 420ms, which is only 0.7% of the total data communication time. However, since 150 vehicle base stations exist in one cell, IP allocation and resetting time of communication time in one cell of the vehicle base station 111 occupy 10.5% of the total data communication time. At this time, if there is no new subscription vehicle, the same IP is allocated, so the individual request time is reduced, but the reset time takes 3.5% of the total superframe interval. Here, the superframe interval is defined as 1s because the period for receiving coordinates and time from the GPS is 1s.

Third, when frequent connections occur with information received from the same vehicle base station, a message storm occurs in which a message related to a plurality of vehicle terminals is transmitted to the vehicle base station in response to an ARP Query update request. Therefore, since the entire network becomes saturated in the busy state, the time-lapse of the system frequently occurs, which causes the network to fall into an inoperable state.

The present invention is to solve the above problems, an object of the present invention is to use the ARP (ARP: Address) for the vehicle terminal by using the context information of the vehicle terminal (VCD: Vehicle Communcation Device) in the vehicle base station (RSU: RoadSide Unit) Resolution Protocol) The purpose is to provide a system for controlling time.

In the V2I network according to the present invention, the ARP time control system includes: a vehicle terminal mounted on a vehicle and performing data communication with a vehicle base station; And receiving a connection request message from the vehicle terminal, receiving the situation information of the vehicle terminal from the vehicle terminal, controlling the ARP time using the situation information of the vehicle terminal, and applying the controlled ARP time to assign an IP to the vehicle terminal. Includes vehicle base stations.

In addition, it is preferable that the vehicle base station controls the ARP time by receiving at least one or more of the information on the speed, location and signal reception strength of the vehicle terminal and the context information of the vehicle terminal including the MAC information of the vehicle terminal.

In addition, when a connection request message is received from the vehicle terminal, the vehicle base station determines whether the previously calculated ARP time is greater than or equal to a preset interval duration, and if the previously calculated ARP time is greater than or equal to the interval duration, It is determined whether the average ARP time of the base station is smaller than the preset standard ARP time, and if the average ARP time of the vehicle base station is smaller than the standard ARP time, the vehicle terminal requests the status information of the vehicle terminal and the ARP time of the neighboring vehicle base station is determined. Request, determine whether the ARP time of the neighboring vehicle base station is less than the standard ARP time, and if the ARP time of the neighboring vehicle base station is less than the standard ARP time, calculate the ARP time for the vehicle terminal using the situation information of the vehicle terminal. To determine whether the calculated ARP time for the vehicle terminal is less than the standard ARP time, the calculated ARP time for the vehicle terminal is the standard. If it is less than the ARP time, it is preferable to assign an IP to the vehicle terminal by applying the ARP time for the vehicle terminal calculated at the vehicle base station.

In addition, if the average ARP time of the vehicle base station is greater than the standard ARP time, the vehicle base station increases the standard ARP time by the preset time at the vehicle base station, and assigns an IP to the vehicle terminal by applying the standard ARP time increased time. It is desirable to.

In addition, if the ARP time of the neighboring vehicle base station is greater than the standard ARP time, the vehicle base station increases the standard ARP time by the preset time at the vehicle base station, and assigns an IP to the vehicle terminal by applying the standard ARP time increased time. It is desirable to.

In addition, if the calculated ARP time for the vehicle terminal is greater than the standard ARP time, the vehicle base station increases the standard ARP time by a preset time at the vehicle base station, and applies the standard ARP time increased to the IP to the vehicle terminal. It is preferable to assign.

In addition, the vehicle base station calculates the difference between the position of the vehicle base station and the position of the vehicle terminal to obtain a distance vector, and initially, the signal reception strength of the signal received from the vehicle terminal and the signal transmission of the signal transmitted from the vehicle base station to the vehicle terminal. The distance between the vehicle terminal and the vehicle base station is calculated using the deviation of the intensity, the noise situation between the vehicle terminal and the vehicle base station is calculated using the distance vector and the distance between the vehicle terminal and the vehicle base station, and the vehicle base station is calculated using the calculated noise situation. Calculate the service range of the vehicle, obtain the service time for the vehicle terminal using the service range of the base station and the speed of the vehicle terminal, and use the average ARP time of the neighboring base station, the average ARP time and the service time of the base station It is desirable to calculate the ARP time for the terminal.

In addition, the vehicle base station,

(Where α, β, and γ are preset weights and α + β + γ = 1 and α <β <γ), and it is preferable to calculate the ARP time for the vehicle terminal.

In addition, the vehicle base station preferably has a standard ARP time of 60 seconds, increases the standard ARP time only up to less than 600 seconds, and assigns an IP to the vehicle terminal by applying the standard ARP time increased time.

According to the present invention, the vehicle base station controls the ARP time for the vehicle terminal according to the situation information of the vehicle terminal, thereby reducing the overhead incurred during the IP update and allocation process.

In addition, by controlling the ARP time for the vehicle terminal by using the status information of the vehicle terminal in the vehicle base station has an effect of reducing the network traffic of the vehicle base station.

In addition, by controlling the ARP time for the vehicle terminal in accordance with the status information of the vehicle terminal at the vehicle base station has an effect of preventing a message storm requiring frequent ARP update from the vehicle terminal to the vehicle base station.

1 is a schematic conceptual diagram of a general WAVE communication system.
2 is a flowchart illustrating a connection process between a conventional vehicle terminal and a vehicle base station.
3 is a diagram illustrating a request time for each connection process between a conventional vehicle terminal and a vehicle base station.
4 is a flowchart illustrating a connection process between a vehicle terminal and a vehicle base station according to an embodiment of the present invention.
5 and 6 are flowcharts illustrating in detail a connection process between a vehicle terminal and a vehicle base station according to an embodiment of the present invention.
7 illustrates a structure of a conventional WBSS message and a structure of a WBSS message according to an embodiment of the present invention.
8 illustrates a structure of a conventional broadcasting message and a structure of a broadcasting message according to an embodiment of the present invention.
9 illustrates the structure of a WSA message.

With reference to the accompanying drawings, a preferred embodiment of the present invention will be described in more detail, but already known technical parts will be omitted or compressed for the sake of brevity of description.

1 is a schematic conceptual diagram of a general WAVE communication system.

Referring to FIG. 1, a WAVE communication system includes a vehicle base station (RSU: Road Side Unit) 111, a vehicle base station router (MC: Middle Network Controller) 130, and a vehicle terminal mounted on a vehicle 150 (VCD: Vehicle). Communication device).

The vehicle base station 111 is fixedly installed on the roadside and provides a connection function between external networks. Here, the vehicle base station 111 according to an embodiment of the present invention enables the connection between the vehicle terminal 153 and the external network.

The vehicle base station router 130 is a device that performs a role of a router between at least one vehicle base station and an external network, and is linked with a CP (Content Provider) for providing various contents.

The vehicle terminal 153 is a device mounted in a vehicle and connected to a terminal platform that interfaces with a user to provide a data communication service to a driver and a passenger.

4 is a flowchart illustrating a connection process between a vehicle terminal and a vehicle base station according to an embodiment of the present invention, and FIGS. 5 and 6 illustrate a connection process between a vehicle terminal and a vehicle base station according to an embodiment of the present invention. It is a flow chart.

Referring to FIG. 4, FIG. 4 is a flowchart illustrating a connection process between a vehicle terminal and a vehicle base station according to an embodiment of the present invention. The conventional vehicle terminal and the vehicle described with reference to FIG. Although the same process as the flow chart showing the connection process between the base station is basically performed, the connection process between the vehicle terminal and the vehicle base station according to an embodiment of the present invention is an ARP address such as S463 in S460 (corresponding to S260 of the conventional invention). Resolution Protocol) A process for controlling time is added. Here, S463 conceptually illustrates the principle of controlling the ARP time for the vehicle terminal 153 in the vehicle base station 111. The S463 step will be described in detail with reference to the following drawings.

5 and 6, the vehicle base station 111 receives a connection message from the vehicle terminal 153 (S510).

Subsequently, the vehicle base station 111 determines whether the previously calculated ARP time is equal to or less than an interval duration (S520), and if it is determined that the previously calculated ARP time is equal to or less than an interval duration, the vehicle base station 111 applies the previously calculated ARP time. The broadcasting process is performed (S5210). Here, the interval period is preferably 100ms.

Subsequently, the vehicle base station 111 determines whether the average ARP time of the current vehicle base station 111 is smaller than the standard ARP time, and if it is determined that the average ARP time of the current vehicle base station 111 is smaller than the standard ARP time, the vehicle base station 111 is determined. ) Requests the vehicle terminal 153 for situation information of the vehicle terminal 153 including the speed, the position (GPS information), and the signal reception strength (RSS value) of the vehicle terminal 153 (S531). Here, the standard ARP time is preferably 60 s.

Subsequently, the vehicle base station 111 receives the average ARP time of the neighboring neighboring vehicle base station 113 (S540) and determines whether the average ARP time of the neighboring vehicle base station 113 is smaller than the standard ARP time (S550). Here, it is preferable that average ARP time is 60s.

If it is determined in step S550 that the average ARP time of the neighboring vehicle base station 113 is smaller than the standard ARP time, the vehicle base station 111 calculates the ARP time using the situation information of the vehicle terminal 153 (S551). Here, the specific principle that the vehicle base station 111 calculates the ARP time using the situation information of the vehicle terminal 153 is as follows.

)와 연결을 요청하는 차량단말기(153)의 위치정보인 GPS 좌표(

)의 차를 이용하여 거리 벡터(

)를 구한다. 이를 수학식으로 나타내면 아래와 같다.First, the vehicle base station 111 is the GPP coordinate of the vehicle base station 111 (

GPS coordinates that are location information of the vehicle terminal 153 requesting connection with

), The distance vector (

). This can be expressed by the following equation.

)와 차량기지국(111)에서 발신한 신호의 신호발신세기(

)의 값을 이용하여 두 개의 신호세기의 편차를 구한다. 이를 수학식으로 나타내면 아래와 같다.Subsequently, the vehicle base station 111 may receive a signal reception intensity (information on signal strength initially received by the vehicle terminal 153 from the vehicle base station 111).

) And the signal transmission strength of the signal transmitted from the vehicle base station 111

Use the value of) to find the deviation of the two signal strengths. This can be expressed by the following equation.

)와 두 개의 신호세기의 편차(

)을 비교하면 전파 상황에 따른 노이즈 상황을 계산할 수 있다. 여기서, 계산의 결과는 차량기지국(111)의 서비스 범위로 계산될 수 있으며, 이를 차량기지국(111)의 서비스 도달 범위(

)로 정의하기로 한다. 여기서, 서비스 거리는 결국 차량의 속도와 반비례하기 때문에 아래와 같은 수학식을 이용하면 차량기지국(111)에 연결을 요청하는 차량단말기(153)에 대한 서비스 시간(

)을 산출할 수 있다. 이를 수학식으로 나타내면 아래와 같다.At this time, the deviation of the two signal strength can be represented by the distance, the distance vector (

) And the difference between the two signal strengths (

), We can calculate the noise situation according to the propagation situation. Here, the result of the calculation may be calculated as the service range of the vehicle base station 111, which is the service reach range of the vehicle base station 111 (

). Here, since the service distance is inversely proportional to the speed of the vehicle, using the following equation, the service time for the vehicle terminal 153 requesting connection to the vehicle base station 111 (

) Can be calculated. This can be expressed by the following equation.

)은 차량기지국(111)에서 IP를 재갱신할 시간과 직접 연관성을 가지기 때문에 다음과 같은 수학식으로 정의할 수 있다.Here, the service time for the vehicle terminal 153 (

) Can be defined by the following equation because it has a direct correlation with the time to renew the IP in the vehicle base station 111.

(Where α, β, γ are preset weights and α + β + γ = 1 and α <β <γ)

That is, the ARP time for the vehicle terminal 153 requesting connection to the vehicle base station 111 may include an average ARP time of the neighboring vehicle base station 113, an average ARP time of the vehicle base station 111, and a service for the vehicle terminal 153. It will be available through time.

Subsequently, the vehicle base station 111 determines whether the ARP time for the vehicle terminal 153 is smaller than the standard ARP time (S560), and if the ARP time for the vehicle terminal 153 is less than the standard ARP time, the vehicle base station 111 ) Performs a broadcasting process to the vehicle terminal 153 by applying a new ARP time calculated in step S551 (S561).

If it is determined in step S520 that the previously calculated ARP time is greater than or equal to the interval period, step S533 is performed to increase the ARP time. Here, step S533 will be described in detail with reference to FIG. 6.

In addition, if it is determined in step S550 that the average ARP time of the neighboring vehicle base station 113 is greater than the standard ARP time, step S533 is performed to increase the ARP time. Here, step S533 will be described in detail with reference to FIG. 6.

In addition, if it is determined in step S560 that the ARP time for the vehicle terminal 153 is greater than the standard ARP time, step S533 is performed to increase the ARP time. Here, step S533 will be described in detail with reference to FIG. 6.

A step S533 of increasing the ARP time at the vehicle base station 111 will be described with reference to FIG. 6. Here, the meaning that the ARP time, the average ARP time, or the ARP time for the vehicle terminal 153 previously calculated by the vehicle base station 111 is larger than the standard ARP time means that the vehicle is in a stalled state or an accident such as low speed or cannot move. It can indicate the status. Accordingly, the vehicle base station 111 should increase the ARP time to minimize the IP exchange or renewal request of the vehicle terminal 153. Here, the method of increasing the ARP time by the vehicle base station 111 is increased by (N + 1) standard ARP time (Std ARP Time) with reference to IEEE 802.3 (N is an integer). At this time, it is desirable to increase the (N + 1) standard ARP time up to 600 s (10 minutes).

Here, N is the number of increase if 1 increases if 1 and if 1 increases 1 (S533a). In addition, the number of increases cannot exceed 10 times, and the maximum value of the ARP time cannot exceed 600 s (10 minutes) (S533e). In addition, if the calculated result is more than 600 s (10 minutes), the value of N is decreased (S533d).

7 illustrates a structure of a conventional WBSS message and a structure of a WBSS message according to an embodiment of the present invention.

The WBSS (WAVES Basic Service Set) message is a message transmitted from the vehicle base station 111 to the vehicle terminal 153 to inform that data communication service is available. Here, the structure of the conventional WBSS message is shown in Figure 7 (a) and the structure of the WBSS message proposed in an embodiment of the present invention is shown in Figure 7 (b).

In the WBSS message structure according to an embodiment of the present invention, a 2-byte WBSS Member field is added between a Frame Control field and a Reservation field of a conventional WBSS message, and the WBSS Member field is a 6-bit MC Number field and a 6-bit WBSS-i field. And a 6-bit WBSS Number field. Here, the WBSS Member field indicates the number of vehicle base stations configured in the vehicle base station router 130 or less, and the WBSS-i indicates a unique number given from the vehicle base station router 130. Here, in one embodiment of the present invention, WBSS-i Member is preferably given in order according to the direction of the road. In addition, MC Number represents a member of the vehicle base station router 130 to which the vehicle base station 111 belongs. If the WBSS proposes 128 vehicle base stations in one vehicle base station router, it can be installed in a space of 60 km or more, even if 30% overlap because one service area is 1 km. Considering the area of Seoul, only 11 vehicle base station routers and the corresponding vehicle base station can provide sufficient service.

Also, the WBSS message structure according to an embodiment of the present invention sets the reservation field of a conventional WBSS message to an Average Speed field including information on average speed of vehicle terminals existing in a service cell of the vehicle base station. do. Through this, the vehicle terminal can quantify the continuous WBSS-i and the average speed as a factor to infer the ARP time allocable to the vehicle terminal based on the average speed in the service area to which the vehicle terminal belongs. Here, in the V2V network other than the V2I network, since the total number of clusters created based on the WBSS Number and WBSS-i and the cluster members to which the vehicle terminal belongs, the cluster members to which the service is continuously provided using the average speed in the cluster are known. May be selected prior to receiving a WSA (WAVE Service Advertisement) message.

In addition, in the WBSS message structure according to an embodiment of the present invention, a BSSID field having a size of 6 bytes of a conventional WBSS message may be set to WBSSID, and the proposed element may be identified using the WBSSID. However, when looking at the contents of 1609.x and IEEE 802.11p, the service providers have different granting techniques, and the WBSS ID can be expressed like a MAC address. That is, the first 3 bytes (24 bits) are defined as the service provider's unique identification number 'OUI' (Organization Unique identifier), and only 3 Oct information indicates vehicle base station information from the manufacturer, so a commonly defined format is required.

8 illustrates a structure of a conventional broadcasting message and a structure of a broadcasting message according to an embodiment of the present invention.

The broadcast message (WSM: WAVE Short Messge) is a message transmitted from the vehicle base station 111 to the vehicle terminal 153 for data communication service. Here, the structure of the conventional broadcasting message is as shown in FIG. 8 (a), and the structure of the broadcasting message proposed in one embodiment of the present invention is as shown in FIG.

In the broadcasting message structure according to an embodiment of the present invention, a total of 3 bytes of fields are added between the Legnth field and the WSM field of a conventional broadcasting message, and the added fields include a 2-byte WBSS Member field, a 3-bit Aveage Speed field, and It consists of a 5-bit Sender State field.

Here, the WBSS Member field includes information about the number of vehicle base stations configured in the vehicle base station router 130 or less, and the Average Speed field includes information on the average speed of vehicle terminals existing in the service cell of the vehicle base station. The Sender State field contains information on the state of the vehicle base station transmitting the broadcasting message.

9 illustrates the structure of a WSA message.

WSA (WSA: WAVE Service Advertisement) is a message informing that the vehicle base station 111 is available through the WBSS to the vehicle terminal 153, the vehicle base station 111 at the vehicle base station 111 using the WSA message The vehicle terminal 153 includes information that IP allocation is possible internally. Here, since the WSA message is a message defined in IEEE 802.11p, the detailed structure thereof will be omitted in an embodiment of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

111, 113: vehicle base station 130: vehicle base station router
150: vehicle 153: vehicle terminal
170: CP

Claims (9)

A vehicle terminal mounted on the vehicle and performing data communication with the vehicle base station; And
When a connection request message is received from the vehicle terminal, the vehicle terminal receives the situation information of the vehicle terminal from the vehicle terminal to control the ARP time using the situation information of the vehicle terminal, and applies the controlled ARP time to the vehicle terminal. Vehicle base station for assigning IP to
ARP time control system in V2I network.
The method of claim 1,
The vehicle base station,
V2I network, characterized in that to control the ARP time by receiving the status information of the vehicle terminal including at least one or more information of the speed, location and signal reception strength of the vehicle terminal and the MAC information of the vehicle terminal ARP time control system.
The method of claim 2,
The vehicle base station,
When a connection request message is received from the vehicle terminal, it is determined whether a previously calculated ARP time is equal to or greater than a preset interval duration,
If the previously calculated ARP time is greater than or equal to the interval period, it is determined whether the average ARP time of the vehicle base station is smaller than a preset standard ARP time,
If the average ARP time of the vehicle base station is less than the standard ARP time, request the situation information of the vehicle terminal to the vehicle terminal and request the ARP time of the neighboring vehicle base station,
Determine whether the ARP time of the neighboring vehicle base station is smaller than the standard ARP time,
If the ARP time of the neighboring vehicle base station is less than the standard ARP time, the ARP time for the vehicle terminal is calculated using the situation information of the vehicle terminal,
It is determined whether the calculated ARP time for the vehicle terminal is smaller than the standard ARP time,
If the calculated ARP time for the vehicle terminal is less than the standard ARP time, the vehicle base station assigns an IP to the vehicle terminal by applying the calculated ARP time for the vehicle terminal. Time control system.

The method of claim 3, wherein
The vehicle base station,
If the average ARP time of the vehicle base station is greater than the standard ARP time, the vehicle base station increases the standard ARP time by a preset time, and assigns an IP to the vehicle terminal by applying the increased standard ARP time. ARP time control system in a V2I network, characterized in that.
The method of claim 4, wherein
The vehicle base station
If the ARP time of the neighboring vehicle base station is greater than the standard ARP time, the vehicle base station increases the standard ARP time by a preset time, and assigns an IP to the vehicle terminal by applying the increased standard ARP time. ARP time control system in a V2I network, characterized in that.
The method of claim 5, wherein
The vehicle base station,
If the calculated ARP time for the vehicle terminal is greater than the standard ARP time, the vehicle base station increases the standard ARP time by a preset time, and applies the standard ARP time increased to the IP to the vehicle terminal. ARP time control system in a V2I network, characterized in that for assigning.
The method according to claim 6,
The vehicle base station,
Calculating a difference between the position of the vehicle base station and the position of the vehicle terminal to obtain a distance vector;
A distance between the vehicle terminal and the vehicle base station is obtained by using the deviation of the signal reception intensity of the signal received from the vehicle terminal initially and the signal transmission intensity of the signal transmitted from the vehicle base station to the vehicle terminal,
Calculate a noise situation between the vehicle terminal and the vehicle base station using the distance vector and the distance between the vehicle terminal and the vehicle base station, calculate a service range of the vehicle base station using the calculated noise situation,
Obtaining a service time for the vehicle terminal using the service range of the vehicle base station and the speed of the vehicle terminal,
And calculating the ARP time for the vehicle terminal using the average ARP time of the neighboring vehicle base station, the average ARP time of the vehicle base station, and the service time.
According to claim 7,
The vehicle base station,
Equation

Where α, β, and γ are preset weights and α + β + γ = 1 and α <β <γ to calculate the ARP time for the vehicle terminal. Control system.
The method of claim 8,
The vehicle base station,
The standard ARP time is 60 seconds,
And increase the standard ARP time to a maximum of less than 600 seconds and assign the IP to the vehicle terminal by applying the increased standard ARP time.

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