JPWO2014061198A1 - Traffic information distribution system, cellular communication system, communication terminal, and traffic information server - Google Patents

Abstract

The cellular communication network (10) is configured to broadcast broadcast information using a downlink physical channel that can be received by a plurality of standby mobile stations. The traffic information server (300) requests the cellular communication network (10) to broadcast the traffic information in the distribution area. The communication terminal (200) is arranged in the automobile (500) and receives traffic information distributed as broadcast information via the cellular communication network (10). Thereby, for example, the latest traffic information can be provided to the passenger of the automobile (500) without delay.

Description

  The present invention relates to a traffic information distribution system.

  One representative example of ITS (Intelligent Transport Systems) is the provision of traffic information to passengers via an in-vehicle device such as a car navigation system. The traffic information provided to the passenger is, for example, traffic jam information, accident information, and safe driving support information. The safe driving support information is, for example, information indicating a dangerous location (e.g. a sharp curve, a tunnel, a location where accidents frequently occur), a recommended traveling speed, road weather information, and the like. The vehicle-mounted device typically receives traffic information by wireless communication with a roadside wireless device (hereinafter referred to as RSU (Road-Side Unit)) installed on the side of the road. Then, the vehicle-mounted device notifies the passenger of traffic information by voice, text, image, or a combination thereof.

  For example, in Japan, an ITS spot service using DSRC (Dedicated Short Range Communications) has been put into practical use. DSRC uses an ISM (Industry-Science-Medical) band of 5.8 GHz band. In the ITS spot service, traffic information is sent from the RSU called ITS spot to the vehicle-mounted device.

  On the other hand, in the field of cellular communication networks, systems that broadcast broadcast information to multiple communication terminals (i.e. mobile stations) are known. A typical example of broadcast information is emergency information. The emergency information includes, for example, an urgent message regarding disasters such as earthquakes and tsunamis. The 3rd Generation Partnership Project (3GPP) defines the architecture and protocol for broadcast distribution of emergency information as CBS (Cell Broadcast Service) and ETWS (Earthquake and Tsunami Warning System).

  The emergency information delivery procedure in UMTS (Universal Mobile Telecommunications System) is defined in 3GPP TS 23.041 as CBS. Further, the emergency information delivery procedure in EPS (Evolved Packet System) is defined as “Warning message delivery procedure” in section 5.12 of 3GPP TS 23.401. FIG. 17 shows a configuration diagram of an emergency information distribution network in UMTS and EPS. FIG. 18 is a sequence diagram showing a procedure for distributing emergency information in UMTS described in 3GPP TS 23.041. FIG. 19 is a sequence diagram showing an emergency information delivery procedure in EPS described in 3GPP TS 23.401, chapter 5.12.

  The CBE (Cell Broadcast Entity) described in FIGS. 17 to 19 is an apparatus / system that makes a transmission request for emergency information. For example, a server of the Japan Meteorological Agency that transmits an earthquake early warning corresponds to CBE. A CBC (Cell Broadcast Center) receives an emergency information transmission request from CBE, determines an emergency information distribution area, and determines the contents of the emergency information. The distribution area is a sector unit, a cell unit, a location registration area (eg routing area, tracking area) unit, based on information for specifying a target area included in the emergency information transmission request received from the CBE, or It is determined in any other area unit determined by the carrier.

  In the case of UMTS, the CBC has an interface with an RNC (Radio Network Controller) or an SGSN (Serving GPRS Support Node). In the examples of FIGS. 17 and 18, the CBC is connected to the RNC. The CBC sends a Write-Replace message to the RNC. The Write-Replace message includes the contents of emergency information to be distributed to the mobile station and the designation of the distribution area. Based on the Write-Replace message, the RNC determines a base station (NodeB) to which emergency information should be distributed, and requests the target base station (NodeB) to broadcast emergency information.

  In the case of UMTS CBS, emergency information is called a “CBS message” and is transmitted using a common traffic channel (CTCH), which is a downlink logical channel. Downlink CTTH is mapped to FACH (Forward Access Channel) which is a transport channel, and transmitted on S-CCPCH (Secondary Common Control Physical Channel) which is a physical channel. Further, the base station (NodeB) transmits CTTH Indicator indicating transmission of downlink CTTH as broadcast information. Specifically, CTTH Indicator is transmitted as one piece of broadcast information (BCCH (Broadcast Control Channel)) transmitted by P-CCPCH (Primary Common Control Physical Channel). Further, the base station (NodeB) transmits a paging message indicating that there is a change in the broadcast information (BCCH) on the S-CCPCH, thereby prompting the mobile station in a standby state to receive the broadcast information.

  In UMTS / UTRAN (UMTS Terrestrial Radio Access Network), a mobile station (UE (User Equipment)) in a standby state (CELL_PCH state, URA_PCH state) receives CTTH included in broadcast information (BCCH) in response to reception of a paging message. Get Indicator. Then, when CTTH Indicator is set, the mobile station starts monitoring CTTH and receives emergency information.

  Furthermore, ETWS (Earthquake and Tsunami Warning System) is defined in 3GPP as an extension of CBS. In ETWS, a Primary Notification message is transmitted using a paging message indicating that there is a change in broadcast information. Primary Notification includes “Warning Type”. Before completing the reception process of “CBS message” as a secondary notification transmitted by CTTH, the mobile station performs a warning operation (eg popup display, alarm sound) to the user in response to receiving the paging message (Primary Notification). Output) can be started quickly. Further, by using the paging message, there is an advantage that the mobile station in the communication state (CELL_DCH state) can also receive the emergency information.

  Distribution of emergency information in the EPS shown in FIG. 19 is also performed with an architecture substantially similar to the above-described UMTS CBS. However, in EPS, the CBC is connected to an MME (Mobility Management Entity), and emergency information is supplied to the base station (eNodeB) via the MME. The base station (eNodeB) transmits an ETWS Indication bit indicating that emergency information is distributed using a paging message. The paging message is mapped to PCH (Paging Channel) and transmitted on PDSCH (Physical Downlink Shared Channel). Then, the base station (eNodeB) transmits emergency information called “ETWS Message” included in broadcast information (SIB (System Information Block)). The ETWS Message includes a “Warning type” as a Primary Notification and a “Warning message” as a Secondary Notification. For example, “Warning type” is transmitted by SIB10, and “Warning message” is transmitted by SIB11. The base station (eNodeB) broadcasts emergency information (ETWS Message) in the cell using BCCH (Broadcast Control Channel) / DL-SCH (Downlink Shared Channel) / PDSCH (Physical Downlink Shared Channel).

  An EPS / E-UTRAN (Evolved UTRAN) mobile station attempts to receive a paging message at least once in the Default Paging Cycle, regardless of whether it is in a standby state (RRC_IDLE state) or a communication state (RRC_CONNECTED state). Then, the mobile station starts receiving broadcast information (SIB) including emergency information in response to receiving a paging message in which the ETWS Indication bit is set.

  Note that the emergency information may be broadcast by using an MBMS (Multimedia Broadcast Multicast Service) system as disclosed in Patent Documents 1 and 2.

JP 2011-61831 A International Publication No. 2006/066629

  RSUs for ITS spot service are installed about every 10 to 15 km on intercity highways and about every 4 km on highways in cities. However, the DSRC communication distance used in the ITS spot service is limited to about several to 30 m. In other words, in the ITS spot service, the RSU communicates with cars passing through the vicinity of the RSU one after another while traveling on the road. In other words, the vehicle-mounted device (that is, the communication terminal) installed in the automobile can communicate with the RSU every time it travels about 4 km or 10 km.

  Since the ITS spot service using DSRC has a short communication distance, it can provide traffic information specialized for a place where a car is located. However, the vehicle-mounted device (communication terminal) installed in the automobile cannot communicate until it approaches the RSU and cannot obtain the latest information. For example, considering the case where RSUs are installed at intervals of 10 km, an automobile traveling at 100 km / h can communicate with the RSU only once every 6 minutes. In addition, when the traveling speed of the automobile is low due to traffic congestion or the like, the interval until the automobile can communicate with the next RSU after it communicates with the RSU is naturally long.

  As understood from the above consideration, when using narrow area communication between an RSU such as an ITS spot service and an in-vehicle device (communication terminal), the latest traffic information cannot be provided to the passenger in real time without delay. There is a fear. One of the objects of the present invention is to provide a traffic information distribution system, a cellular communication system, a communication terminal, a traffic information server, and a method and a program related thereto that can provide the latest traffic information to passengers without delay. That is.

  In the first aspect, the traffic information distribution system includes a cellular communication network, a traffic information server, and a communication terminal. The cellular communication network is configured to broadcast broadcast information using a downlink physical channel that can be received by a plurality of mobile stations in a standby state. The traffic information server is configured to request the cellular communication network for broadcast distribution of traffic information within a distribution area. The communication terminal is arranged in an automobile and is configured to receive the traffic information distributed as the broadcast information via the cellular communication network.

  In the second aspect, the cellular communication system includes a distribution server and a network. The distribution server receives a request for broadcast distribution of traffic information within the distribution area from the traffic information server. The network communicates with the distribution server and uses the downlink physical channel that can be received by a plurality of standby mobile stations in a first cell group including at least one cell corresponding to the distribution area. Broadcast information.

  In the third aspect, the communication terminal includes a cellular communication unit and a control unit. The cellular communication unit receives traffic information broadcast from a cellular communication network on a downlink physical channel that can be received by a plurality of mobile stations in a standby state. The control unit controls to notify the user of the traffic information.

  In the fourth aspect, the traffic information server includes a determination unit and a communication unit. The determination unit determines a traffic information distribution area. In the cellular communication network, the communication unit is configured to broadcast the traffic information using a downlink physical channel that can be received by a plurality of standby mobile stations in at least one cell corresponding to the distribution area. Communicate with the distribution server.

In a fifth aspect, a communication terminal control method includes:
(A) receiving traffic information broadcast from a cellular communication network in a downlink physical channel that can be received by a plurality of mobile stations in a standby state; and (b) notifying the user of the traffic information.
including.

In a sixth aspect, the traffic information server control method comprises:
(A) determining a traffic information distribution area; and (b) using at least one cell corresponding to the distribution area, the traffic information using a downlink physical channel that can be received by a plurality of standby mobile stations. Communicate with a distribution server in a cellular communication network to broadcast
including.

  In the seventh aspect, the program includes a group of instructions for causing a computer to perform the communication terminal control method according to the fifth aspect described above.

  In the eighth aspect, the program includes a group of instructions for causing a computer to perform the traffic information server control method according to the sixth aspect described above.

  According to the above-described aspect, it is possible to provide a traffic information distribution system, a cellular communication system, a communication terminal, a traffic information server, and a method and program related thereto that can provide the latest traffic information to passengers without delay.

It is a figure which shows the structural example of the traffic information delivery system which concerns on 1st Embodiment. It is a sequence diagram which shows the delivery procedure of the traffic information in the traffic information delivery system which concerns on 1st Embodiment. It is a figure which shows the structural example of the communication terminal which concerns on 1st Embodiment. It is a figure which shows the structural example of the traffic information server which concerns on 1st Embodiment. It is a figure which shows the structural example of the traffic information delivery system which concerns on 2nd Embodiment. It is a flowchart which shows an example of operation | movement of the cellular communication system which concerns on 3rd Embodiment. It is a flowchart which shows an example of operation | movement of the cellular communication system which concerns on 3rd Embodiment. It is a block diagram which shows the structural example of the communication terminal which concerns on 4th Embodiment. It is a flowchart which shows an example of operation | movement of the communication terminal which concerns on 4th Embodiment. It is a block diagram which shows the structural example of the communication terminal which concerns on 5th Embodiment. It is a flowchart which shows an example of operation | movement of the communication terminal which concerns on 5th Embodiment. It is a block diagram which shows the structural example of the communication terminal which concerns on 6th Embodiment. It is a figure which shows the structural example of the traffic information delivery system which concerns on 7th Embodiment. It is a flowchart which shows an example of operation | movement of the cellular communication system which concerns on 7th Embodiment. It is a flowchart which shows an example of operation | movement of the cellular communication system which concerns on 7th Embodiment. It is a block diagram which shows the structural example of the traffic information server which concerns on 7th Embodiment. It is a figure which shows the structure of the delivery network of simultaneous transmission information (e.g. emergency information) in UMTS and EPS which concerns on background art. It is a sequence diagram which shows the delivery procedure of the broadcast information (e.g. emergency information) in UMTS which concerns on background art (in the case of UMTS). It is a sequence diagram which shows the delivery procedure of the simultaneous transmission information (e.g. emergency information) in EPS which concerns on background art (in the case of EPS).

  Hereinafter, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted as necessary for clarification of the description.

<First Embodiment>
FIG. 1 is a block diagram illustrating a configuration example of a traffic information distribution system 1 according to the present embodiment. The traffic information distribution system 1 includes a cellular communication system 10, a communication terminal 200 disposed in an automobile 500, and a traffic information server 300. The cellular communication system 10 is configured to broadcast broadcast information using a downlink physical channel that can be received by a plurality of mobile stations (including the communication terminal 200) in a standby state. Such broadcast delivery by the cellular communication system 10 may be referred to as cell broadcast below. The cellular communication system 10 shown in FIG. 1 includes a broadcast distribution server 100, a control node 110, and a base station 120 as nodes related to cell broadcast.

  The cellular communication system 10 is, for example, a UMTS, EPS, or CDMA2000 system. For example, the cellular communication system 10 may transmit broadcast information in units of sectors, cells, multiple cells, or location registration areas by CBS, ETWS, or BC-SMS (Broadcast Short Message Service). BC-SMS is a broadcast delivery method standardized in CDMA2000 of 3GPP2 (Third Generation Partnership Project 2). Hereinafter, broadcast delivery of broadcast information by the cellular communication system 10 will be briefly described.

  The broadcast delivery server 100 corresponds to a CBC (Cell Broadcast Center) in UMTS or EPS. That is, the broadcast distribution server 100 determines a sector, a cell, a cell group, or a location registration area for distributing broadcast transmission information. The control node 110 is a node having an interface with the broadcast distribution server 100 (CBC). In the case of EPS, MME (Mobility Management Entity) corresponds to the control node 110, and in the case of UMTS, RNC (Radio Network Controller) corresponds to the control node 110. The control node 110 receives a broadcast information distribution request (e.g. Write-Replace message or Write-Replace Warning Request) from the broadcast distribution server 100. The broadcast transmission information distribution request includes the content of the broadcast transmission information to be distributed to mobile stations (including the communication terminal 200) and designation of a distribution target sector, cell, cell group, or location registration area. The control node 110 determines the base station 120 that should perform cell broadcast, and requests the target base station 120 to broadcast the broadcast information.

  The base station 120 manages the cell 130 and can perform bidirectional wireless communication with the mobile station using the uplink physical channel and the downlink physical channel. Cell 130 covers road 510. In the case of EPS, the eNodeB corresponds to the base station 120, and in the case of UMTS, the NodeB corresponds to the base station 120. In response to receiving the broadcast information distribution request (e.g. Broadcast Request or Write-Replace Warning Request) from the control node 110, the base station 120 performs cell broadcast of the broadcast information. The base station 120 transmits simultaneous transmission information (e.g. CBS message or ETWS Message) using broadcast information and a paging message. Broadcast information including paging information and paging messages are downlink physical channels that can be received by mobile stations (including communication terminal 200) at least in a standby state (ie E-UTRAN RRC_IDLE state, UTRAN CELL_PCH state or URA_PCH state) (Eg E-UTRAN PDSCH, UTRAN P-CCPCH and S-CCPCH).

  The communication terminal 200 has a function of a mobile station that can communicate with the cellular communication system 10 and is configured to receive broadcast information distributed from the base station 120. The communication terminal 200 receives the broadcast transmission information at least in a standby state (e.g. E-UTRAN RRC_IDLE state, UTRAN CELL_PCH state, or URA_PCH state). The communication terminal 200 in the standby state cannot transmit and receive user data, and receives a paging channel including a paging message transmitted from the cellular communication system 10. The communication terminal 200 may receive the broadcast transmission information even in a communication state (e.g. RRC_CONNECTED state of E-UTRAN or CELL_DCH state of UTRAN). EPS and UMTS mobile stations also receive paging signals in the communication state (e.g. ERCUT RRC_CONNECTED state or UTRAN CELL_DCH state). Therefore, when the communication terminal 200 has the function of an EPS or UMTS mobile station, the communication terminal 200 can receive broadcast information even in a communication state.

  Communication terminal 200 is arranged in car 500 traveling on road 510. For example, the communication terminal 200 may be an in-vehicle device (e.g. car navigation system) fixedly installed in the automobile 500. Communication terminal 200 may be a portable terminal such as a smartphone or a mobile phone terminal. The communication terminal 200 notifies the user (that is, the passenger of the car 500) of traffic information. The notification of traffic information may be performed by voice, text, image, or a combination thereof. That is, the communication terminal 200 may output voice, text, images, and the like based on traffic information to an output device such as a display or a speaker.

  The traffic information server 300 is coupled to the cellular communication system 10 to distribute traffic information as broadcast information. The traffic information server 300 is configured to request the cellular communication system 10 to broadcast a cell broadcast of traffic information into the distribution area. Specifically, the traffic information server 300 may transmit to the broadcast distribution server 100 indicating the content and distribution area of the traffic information.

  Furthermore, the traffic information server 300 may determine the content and distribution area of the traffic information. In order to determine the content and distribution area of the traffic information, sensor information, probe information collected from the automobile 500, or both may be used. The sensor information is information collected by a sensor 520 (e.g. an optical sensor for vehicle detection) installed around the road 510. The probe information is information collected from the automobile 500, and includes, for example, position information, acceleration information, speed information, accelerator operation information, or any combination of these. The probe information may be collected by the RSU 530 installed around the road 510 or may be collected via the cellular communication system 10. The information collection system 310 illustrated in FIG. 1 collects sensor information, probe information, and the like from the sensor 520, the RSU 530, or the cellular communication system 10.

  As already described, the traffic information is, for example, traffic jam information, accident information, and safe driving support information. Further, the traffic castle information may be information for guiding the automobile 500 so as to avoid or relieve the traffic jam when the occurrence of the traffic jam is predicted. For example, the traffic information server 300 determines an area including a change point from the downhill to the uphill of the road 510 as a distribution area, and determines the distribution of the traffic information including a message that prompts attention to speed reduction or speed maintenance. May be. In addition, the traffic information server 300 determines an area including a junction (eg interchange, junction) of the road 510 as a distribution area, and distributes traffic information including a message for guiding the car 500 traveling on the road 510 to the overtaking lane. May be determined.

  In response to the request from the traffic information server 300, the cellular communication system 10 cell-broadcasts traffic information as broadcast information. The broadcast delivery server 100 may determine a sector, cell, cell group, or location registration area corresponding to the delivery area notified from the traffic information server 300 as a delivery destination of the broadcast transmission information (here, traffic information). .

  FIG. 2 is a sequence diagram illustrating an example of a traffic information distribution procedure according to the present embodiment. In step S101, the traffic information server 300 determines the content of traffic information to be distributed and its distribution area. In step S102, the traffic information server 300 transmits a distribution request indicating the traffic information and its distribution area to the cellular communication system 10 (specifically, the broadcast distribution server 100). In step S103, the cellular communication system 10 determines a sector, a cell, a cell group, or a location registration area where the traffic information is to be distributed in response to the reception of the distribution request from the traffic information server 300.

  In step S104, the cellular communication system 10 broadcasts traffic information as broadcast information to the cell 130. The broadcast delivery in step S104 may be the same as the delivery procedure such as CBS, ETWS, or BC-SMS described in the background art. For example, the cellular communication system 10 may transmit traffic information (e.g. CBS Message or ETWS Message) as broadcast information using broadcast information and a paging signal.

  In step S105, the communication terminal 200 receives the traffic information and notifies the passenger of the car 500 of the traffic information.

  FIG. 3 is a block diagram illustrating a configuration example of the communication terminal 200 according to the present embodiment. The cellular communication unit 201 receives traffic information broadcast from the cellular communication network on a downlink physical channel that can be received by a mobile station in a standby state. The control unit 202 notifies the traffic information to the user (that is, the passenger of the car 500).

  FIG. 4 is a block diagram illustrating a configuration example of the traffic information server 300 according to the present embodiment. The determination unit 301 determines a traffic information distribution area. The determination part 301 should just determine the delivery area of traffic information based on sensor information or probe information, or both, for example. Furthermore, the determination part 301 may determine the content of traffic information. The communication unit 302 communicates with the broadcast distribution server 100 and transmits a traffic information distribution request to the broadcast distribution server 100.

  As described above, the traffic information distribution system 1 according to the present embodiment uses a broadcast transmission function for broadcast information included in the cellular communication system 10 (for example, UMTS, EPS, or CDMA2000) to a specific distribution area. Traffic information is distributed to the corresponding sector, cell, cell group, or location registration area. The base station 120 (cell 130) of the cellular communication system 10 generally has a larger coverage than the RSU 530 used in the DSRC ITS spot service. For this reason, the traffic information distribution system 1 can transmit traffic information in a wide range all at once as compared with RSU or the like of ITS spot service. The traffic information distribution system 1 uses a distribution method such as CBS, ETWS, or BC-SMS that can be received while the mobile station is in a standby state. For this reason, the communication terminal 200 can receive traffic information without delay. Therefore, according to this embodiment, the latest traffic information can be provided to the passenger without delay.

<Second Embodiment>
In the present embodiment, a modification of the cellular communication system 10 according to the first embodiment will be described. FIG. 5 is a diagram illustrating a configuration example of the cellular communication system 10 according to the present embodiment. In response to a traffic information distribution request from the traffic information server 300, the cellular communication system 10 according to the present embodiment broadcasts different broadcast transmission information to a plurality of cells or a plurality of cell groups. In the example of FIG. 5, cellular communication system 10 includes base stations 120A, 120B, and 120C. Base stations 120A, 120B, and 120C manage cells 130A, 130B, and 130C, respectively. The cells 130 </ b> A, 130 </ b> B, and 130 </ b> C are arranged along the road on the road 510 and cover the road 510.

  In the example of FIG. 5, the cellular communication system 10 broadcasts a first message (message A) based on traffic information in the cell 130A, and is different from the first message to the cells 130B located around the cell 130A. Broadcast the second message (message B). In addition, the cellular communication system 10 broadcasts a third message (message C) different from the first message to cells 130C located around the cell 130A. Note that the cells 130A, 130B, and 130C may be cell groups or location registration areas including a plurality of cells instead of one cell.

  The first message may be the traffic information itself requested by the traffic information server 300 for distribution. On the other hand, the second or third message may be urged not to notify the user of the first information corresponding to the traffic information received at the communication terminal 200 via the inter-vehicle communication. This scheme is effective when inter-vehicle communication can be used between the automobiles 500. For example, by transmitting traffic information between vehicles 500 via inter-vehicle communication, the vehicle 500 that does not support the distribution of traffic information via the cellular communication system 10 can also use the traffic information. However, there is a possibility that traffic information may be transmitted to the automobile 500 located outside the cell 130A via inter-vehicle communication. Notifying the passenger of the automobile 500 located outside the cell 130A of this traffic information is not an operation required by the traffic information server 300. Therefore, by requesting the communication terminal 200 located in the cell 130B (or 130C) to suppress notification of traffic information received via inter-vehicle communication, unnecessary traffic information is transmitted to the passenger. Can be prevented.

  The second or third message may be urged not to transfer the first information corresponding to the traffic information received at the communication terminal 200 via the inter-vehicle communication to the other communication terminal 200. Thereby, it is possible to prevent the traffic information from being transmitted unnecessarily to the range exceeding the cell 130A via the inter-vehicle communication.

  The first, second, and third messages may indicate different speed limit contents or different driving operations. For example, when the cell 130A is a traffic jam occurrence point, the first message (message A) may instruct the communication terminal 200 located in the cell 130A to run at a low speed (for example, 40 km / h). On the other hand, the second message (message B) may instruct relatively high speed travel (for example, 60 km / h) to the communication terminal 200 in the cell 130B located in front of the traffic congestion occurrence point. In addition, the third message (message C) may instruct normal travel (for example, 100 km / h) to the communication terminal 200 in the cell 130C that is past the place where the traffic congestion has occurred. In this way, it is possible to control in detail the travel of the automobile 500 in the vicinity of the traffic jam occurrence location. This control can be applied not only to traffic jams but also to other traffic obstacles.

<Third Embodiment>
In the present embodiment, a modification of the communication terminal 200 according to the first embodiment will be described. A configuration example of the traffic information distribution system 1 in the present embodiment may be the same as that in FIG. In the present embodiment, after receiving the traffic information as the broadcast information, the communication terminal 200 suppresses repeatedly receiving the downlink physical channel for receiving the traffic information. When CBS, ETWS, or BC-SMS is used for the distribution of earthquake information, the cellular communication system typically only needs to distribute the earthquake information once. However, the circumstances differ in the distribution of traffic information described in the first embodiment. That is, the cellular communication system 10 needs to continuously broadcast and distribute traffic information as broadcast information while traffic jams, obstacles, weather conditions, and the like notified by the traffic information continue. When broadcast information is broadcast continuously, a normal communication terminal repeatedly receives downlink physical channels (eg E-UTRAN PDSCH, UTRAN P-CCPCH and S-CCPCH). On the other hand, since the communication terminal 200 of this embodiment suppresses repeatedly receiving a downlink physical channel for reception of traffic information, it does not repeatedly receive the same traffic information and can reduce power consumption.

  The flowcharts of FIGS. 6 and 7 show an operation example of the communication terminal 200 according to the present embodiment. In the first example shown in FIG. 6, the communication terminal 200 receives traffic information distributed by cell broadcast (step S201). And the communication terminal 200 suppresses repeatedly receiving a downlink physical channel for reception of traffic information in the same cell, the same cell group, or the same position registration area as the cell which received traffic information. (Step S202).

  In the second example shown in FIG. 7, the communication terminal 200 receives traffic information distributed by cell broadcast (step S301). And the communication terminal 200 suppresses receiving a downlink physical channel repeatedly for reception of traffic information within a predetermined period after receiving traffic information (step S302).

<Fourth Embodiment>
In the present embodiment, a modification of the communication terminal 200 according to the first embodiment will be described. A configuration example of the traffic information distribution system 1 in the present embodiment may be the same as that in FIG. In the present embodiment, the communication terminal 200 has an inter-vehicle communication function. FIG. 8 is a block diagram illustrating a configuration example of the communication terminal 200 according to the present embodiment. The inter-vehicle communication unit 203 performs wireless communication with other communication terminals arranged in other automobiles 500. For example, the vehicle-to-vehicle communication unit 203 may transfer traffic information received from the cellular communication system 10 via the cellular communication unit 201 to another communication terminal. The inter-vehicle communication unit 203 may receive traffic information from other communication terminals. For distinction, the traffic information received from the cellular communication system 10 is referred to as “traffic information X”, and the traffic information transmitted or received via the inter-vehicle communication unit 203 is referred to as “traffic information Y”.

The flowchart of FIG. 9 shows an operation example of the communication terminal 200 according to the present embodiment.
In step S401, the communication terminal 200 receives the traffic information Y from other communication terminals by inter-vehicle communication. In step S402, the communication terminal 200 determines whether or not the traffic information X corresponding to the traffic information Y has been received from the cellular communication system 10. The fact that the traffic information X corresponds to the traffic information Y means, for example, that these two pieces of information have the same content, or belong to the same genre (for example, traffic jam, confluence notice, or weather conditions). If the traffic information X corresponding to the traffic information Y has not been received (NO in step S402), the communication terminal 200 transfers the received traffic information Y to another terminal (step S403). On the other hand, when the traffic information X corresponding to the traffic information Y has been received (YES in step S402), the communication terminal 200 suppresses the transfer of the traffic information Y (step S404).

  According to the operation shown in FIG. 9, it is possible to prevent the traffic information Y from being propagated indefinitely. In addition, the traffic information X received directly from the cellular communication system 10 by the communication terminal 200 may be more reliable than the traffic information Y received by inter-vehicle communication. According to the operation shown in FIG. 9, high-reliability information received via the cellular communication system 10 can be prioritized. For example, the communication terminal 200 may transfer the traffic information X instead of the traffic information Y to another communication terminal.

<Fifth Embodiment>
In the present embodiment, a modification of the communication terminal 200 according to the first embodiment will be described. A configuration example of the traffic information distribution system 1 in the present embodiment may be the same as that in FIG. In the present embodiment, the communication terminal 200 changes the probe information reporting operation in response to receiving traffic information broadcast from the cellular communication system 10. As described above, the probe information is information collected from the automobile 500 and includes, for example, position information, acceleration information, speed information, accelerator operation information, or any combination of these. The probe information is collected by, for example, the broadcast distribution server 100, the traffic information server 300, the information collection system 310, or other devices. The communication terminal 200 may transmit probe information via the cellular communication system 10, or may transmit probe information via an RSU such as an ITS spot installed in the vicinity of the road 510.

  The change of the probe information reporting operation by the communication terminal 200 includes, for example, (a) starting the reporting of probe information, (b) stopping the reporting of probe information, and (c) changing the reporting period of probe information. Including at least one of the following. For example, in response to receiving traffic information, the communication terminal 200 starts the probe information reporting operation or shortens the reporting cycle, so that the traffic information server 300 or the information collection system 310 notifies the traffic information. It is possible to verify the effect of avoiding or mitigating traffic jams. The traffic information server 300 monitors the probe information, and when the traffic information notification effect is not sufficient, the traffic information content is changed, or the traffic information notification method is changed by the communication terminal 200 (for example, a warning sound is changed). May be performed.

  FIG. 10 is a block diagram illustrating a configuration example of the communication terminal 200 according to the present embodiment. The probe information report unit 204 shown in FIG. 10 transmits probe information via the cellular communication system 10. The control unit 202 controls the probe information reporting operation by the probe information reporting unit 204 in response to reception of traffic information.

  The flowchart in FIG. 11 illustrates an operation example of the communication terminal 200 according to the present embodiment. In step S501, the communication terminal 200 receives traffic information distributed by cell broadcast. In step S502, the communication terminal 200 changes the probe information reporting operation in response to receiving the traffic information.

<Sixth Embodiment>
In the present embodiment, a modification of the communication terminal 200 according to the first embodiment will be described. A configuration example of the traffic information distribution system 1 in the present embodiment may be the same as that in FIG. In this embodiment, the communication terminal 200 has traffic information (referred to as traffic information X) via the cellular communication system 10 and other traffic information (referred to as traffic information Z) via the RSU 530 installed around the road 510. When both are received, prioritization of these two pieces of traffic information X and Z is performed. For example, the communication terminal 200 may notify the passenger of only one of the two pieces of traffic information X and Z having a higher priority. If a plurality of similar traffic information is notified or different traffic information is notified, it becomes a factor to confuse the passenger. According to the priority control of the present embodiment, these situations that cause confusion to the passenger can be avoided.

  For example, when high reliability is set for the traffic information Z via RSU, the communication terminal 200 notifies the user of the traffic information Z preferentially when both the traffic information X and Z are received. May be. On the other hand, when high reliability is set for the traffic information X via the cellular communication system 10, the communication terminal 200 gives priority to the traffic information X when both the traffic information X and Z are received. The user may be notified.

  FIG. 12 is a block diagram illustrating a configuration example of the communication terminal 200 according to the present embodiment. The DSRC communication unit 205 shown in FIG. 12 communicates with the RSU 530 by the DSRC method. The DSRC communication unit 205 sends the traffic information Z received from the RSU 530 to the control unit 202. The control unit 202 shown in FIG. 12 prioritizes the two pieces of traffic information X and Z, and controls traffic information notification to the passenger.

<Seventh Embodiment>
In the present embodiment, a modification of the cellular communication system 10 according to the first embodiment will be described. FIG. 13 is a diagram illustrating a configuration example of the cellular communication system 10 according to the present embodiment. In the present embodiment, the communication terminal 200 is configured to transmit an acknowledgment indicating the reception status of traffic information broadcasted by the cell to the cellular communication system 10. More preferably, the communication terminal 200 is in a standby state (eg RRC_IDLE state of the ERC-UTRAN or UTRAN CELL_DCH state) (e.g. RRC_IDLE state of the ETRAN-UTRAN), UTRAN The CELL_PCH state or the URA_PCH state) can be transmitted to the cellular communication system 10 with an acknowledgment indicating the traffic information reception status. The cellular communication system 10 is configured to receive confirmation responses indicating the traffic information reception status from a plurality of communication terminals 200.

  In order to send and receive an acknowledgment response regarding emergency information between the communication terminal 200 in the standby state and the cellular communication system 10, the communication terminal 200 sends an acknowledgment using a signaling message terminated in the access layer (Access Stratum). Just send it. The signaling message terminated at the access layer (Access Stratum) is a signaling message used in the Access Stratum protocol. The Access Stratum protocol is a protocol that handles signals terminated by nodes in a radio access network (i.e. UTRAN or E-UTRAN), i.e., eNodeB, NodeB, or RNC. In the case of E-UTRAN and UTRAN, the Access Stratum protocol includes RRC (Radio Resource Control), RLC (Radio Link Control), and MAC (Medium Access Control).

  More specifically, the communication terminal 200 may transmit an acknowledgment using an RRC signaling message (RRC message) that is a layer 3 control plane (C plane) protocol. In this case, the acknowledgment is received by the node that terminates the RRC in the cellular communication system 10. That is, in the case of E-UTRAN, the base station (eNodeB) 120 receives the confirmation response transmitted using the RRC message. In the case of UTRAN, typically, the control node (RNC) 110 receives the confirmation response transmitted using the RRC message. Note that the UTRAN base station (NodeB) 120 may receive an acknowledgment by monitoring the RRC message.

  Subsequently, a logical channel, a transport channel, and a physical channel that can be used by the communication terminal 200 in a standby state to transmit an acknowledgment regarding traffic information will be described in detail. In the case of E-UTRAN, the standby state corresponds to the RRC_IDLE state. The communication terminal 200 in the RRC_IDLE state transmits an acknowledgment without changing to the communication state (RRC_CONNECTED state), in other words, without setting up an RRC (Radio Resource Control) connection with the cellular communication system 10. For this purpose, the communication terminal 200 transmits a transport channel UL-SCH (Uplink Shared Channel) transmitted in the physical channel PUSCH (Physical Uplink Shared Channel) as in the RRC Connection Request message transmitted to request an RRC connection. The confirmation response may be transmitted to the base station (eNodeB) 120 using the logical channel CCCH (Common Control channel).

  In the case of UTRAN, the standby state corresponds to the CELL_DCH state or the CELL_FACH state. The communication terminal 200 in the CELL_DCH state or the CELL_FACH state allocates uplink dedicated physical channels (DPDCH (Dedicated Physical Data Channel) and DPCCH (Dedicated Physical Control Channel)) without changing to the communication state (CELL_DCH state). Send an acknowledgment without receiving it. For this purpose, the communication terminal 200 uses the transport channel RACH (Random Access Channel) and the logical channel CCCH (Common Control Channel) transmitted in the physical channel PRACH (Physical Random Access Channel) to establish the base station (NodeB) 120. The confirmation response may be transmitted to the control node (RNC) 110 via the route.

  The node (base station 120 or control node 110) in the cellular communication system 10 that has received the confirmation response from the communication terminal 200 is a higher-order node (control node 110 or broadcast distribution server 100) on the traffic information distribution route. In response to this, a confirmation response from the communication terminal 200 may be transferred. At this time, the confirmation responses from the communication terminal 200 may be transferred individually as they are, or may be transferred as appropriate at each node.

  As described above, in a preferred example of the present embodiment, each communication terminal 200 receives cell-broadcast traffic information while remaining in a standby state (eg, ERCUT RRC_IDLE state, UTRAN CELL_PCH state, or URA_PCH state). An acknowledgment indicating the situation is transmitted to the cellular communication system 10. In addition, the cellular communication system 10 receives confirmation responses indicating the traffic information reception status from the plurality of communication terminals 200 in the standby state. Therefore, the communication terminal 200 does not need to transition to a communication state in which user data can be transmitted / received. Further, signaling for state transition of the communication terminal 200 does not occur frequently between the nodes (base station, MME, RNC, S-GW, SGSN, etc.) arranged in the cellular communication system 10 and the communication terminal 200. . Thereby, the preferable example of this embodiment can perform efficiently transmission of the confirmation response by the communication terminal 200 with respect to the traffic information cell-broadcasted from the cellular communication system 10, suppressing the load increase of the cellular communication system 10. .

  Subsequently, a specific example of a procedure for collecting confirmation responses to traffic information will be described below. FIG. 14 is a sequence diagram showing a specific example when the cellular communication system 10 is an EPS. In step S601, the communication terminal 200 is in a standby state (RRC_IDLE state), and periodically and intermittently receives a paging signal. In step S602, traffic information (ETWS Message) is broadcast from the cellular communication system to the communication terminal 200. The broadcast delivery in step S602 may be the same as the delivery procedure described in the background art (FIG. 19). As described in the first embodiment, emergency information (ETWS) is used by using broadcast information and a paging signal. Message) may be transmitted. Therefore, the detailed description regarding the broadcast distribution procedure of traffic information is omitted here.

  In step S603, the communication terminal 200 transmits an acknowledgment (Ack send Request) regarding the reception status of traffic information to the base station (eNodeB) 120 while remaining in the standby state. In the example of FIG. 14, the confirmation response is transmitted using the RRC message. Further, the example of FIG. 14 illustrates a case where the confirmation response is ACK indicating normal reception of traffic information. The acknowledgment (Ack send Request) includes an identifier (message ID) that can identify the traffic information received by the communication terminal 200, an identifier of the communication terminal 200 that is the transmission source (for example, International Mobile Subscriber Identity (IMSI), IMEI ( International Mobile Equipment Identity), TMSI (Temporary Mobile Subscriber Identity), or M-TMSI (MME-TMSI)).

  In step S604, a response indicating that the base station 120 has received the confirmation response is transmitted to the communication terminal 200. In addition, in order to avoid the load of the base station 120 and congestion of the radio access network, the response transmission in step S604 may be omitted.

  In step S605, the base station 120 aggregates a plurality of confirmation responses received from the plurality of communication terminals 200, and displays an confirmation response report (Ack Report) edited so as to integrate the confirmation responses from the plurality of communication terminals 200. create. In step S606, the base station 120 transmits an acknowledgment report to the control node (MME) 110. The confirmation response report includes an identifier (message ID) that can specify traffic information and an identifier list (for example, a TMSI list) of a plurality of communication terminals 200 that are transmission sources of the confirmation response corresponding to the message ID. Note that the transmission of the confirmation report in step S606 may be performed using a control interface (e.g. S1-MME interface) that can be used between the base station (eNodeB) 120 and the control node (MME) 110.

  In step S607, the control node (MME) 110 receives an acknowledgment report from each of the plurality of base stations 120. Then, the control node 110 further aggregates the received plurality of confirmation response reports, creates an acknowledgment report edited so as to integrate the reports from the plurality of base stations 120, and transmits the confirmation response report to the broadcast distribution server (CBC). ) 100 (step S608).

  Next, the case of UMTS will be described. FIG. 15 is a sequence diagram showing an example of a procedure for collecting confirmation responses when the cellular communication system 10 is UMTS. In step S701, the communication terminal 200 is in a standby state (CELL_PCH state or URA_PCH state), and periodically and intermittently receives a paging signal. In step S702, traffic information (CBS Message) is broadcast from the cellular communication system 10 to the communication terminal 200. Note that the broadcast distribution in step S702 may be the same as the distribution procedure described in the background art (FIG. 18), and traffic information (CBS Message) using the broadcast information and the paging signal as described in the first embodiment. ). Therefore, the detailed description regarding the broadcast distribution procedure of traffic information is omitted here.

  In step S <b> 703, the communication terminal 200 transmits an acknowledgment (Ack send Request) regarding the traffic information reception status to the control node (RNC) 110 in the standby state. In the example of FIG. 15, the confirmation response is transmitted using the RRC message. Further, the example of FIG. 15 shows a case where the confirmation response is ACK indicating normal reception of traffic information. The acknowledgment (Ack send Request) includes an identifier (message ID) that can specify traffic information and an identifier (for example, IMSI, IMEI, TMSI, or P-TMSI (Packet TMSI)) of the communication terminal 200 that is the transmission source. .

  In step S704, the control node 110 transmits to the communication terminal 200 a response indicating that the confirmation response has been received. In order to avoid the load on the control node 110 and the congestion of the radio access network, the response transmission in step S704 may be omitted.

  In step S705, the control node 110 aggregates a plurality of confirmation responses received from the plurality of communication terminals 200, and displays an confirmation response report (Ack Report) edited so as to integrate the confirmation responses from the plurality of communication terminals 200. create. In step S706, the control node 110 transmits an acknowledgment report to the broadcast distribution server (CBC) 100. The confirmation response report includes an identifier (message ID) that can specify traffic information and an identifier list (for example, a TMSI list) of a plurality of communication terminals 200 that are transmission sources of the confirmation response corresponding to the message ID.

  Next, an example of the operation of the cellular communication system 10 or the traffic information server 300 that has received a response (for example, confirmation response report) of the communication terminal 200 to the broadcast distribution of traffic information will be described. In one example, the cellular communication system 10 or the traffic information server 300 changes the traffic information distribution method according to the reception status of confirmation responses from the plurality of communication terminals 200. For example, (a) distribution of traffic information using an intelligent transportation system (ITS) including an RSU 530 installed around the road 510, and (b) inter-vehicle communication of the communication terminal 200. Transferring traffic information to other communication terminals using the function, and (c) changing the upper limit of the number of hops when transferring traffic information to other communication terminals by the inter-vehicle communication function of the communication terminal 200, Including at least one.

  For example, when the number of confirmation responses received from a plurality of communication terminals 200 is equal to or less than a threshold, it can be determined that traffic information by cell broadcast has not been sufficiently received. For this reason, the cellular communication system 10 or the traffic information server 300, when the number of confirmation responses received is equal to or less than the threshold, other distribution methods, for example, distribution from the RSU 530 or other distribution using the inter-vehicle communication function , May be used. The cellular communication system 10 or the traffic information server 300 may increase the upper limit of the number of hops in the inter-vehicle communication when the number of confirmation responses received is equal to or less than the threshold. According to these methods, traffic information can be transmitted to the automobile 500 (communication terminal 200) using other communication means in a situation where distribution of traffic information by cell broadcast is not sufficiently functioning.

  FIG. 16 is a block diagram illustrating a configuration example of the traffic information server 300 that can change the traffic information distribution method. The determination unit 301 illustrated in FIG. 16 receives the confirmation response report collected by the cellular communication system 10 via the communication unit 302. The confirmation response report indicates the reception status of the traffic information subjected to cellular communication by the plurality of communication terminals 200. The determination unit 301 changes the traffic information distribution method as necessary based on the confirmation response report.

<Other embodiments>
The first to seventh embodiments described above may be implemented in combination as appropriate.

  In the first to seventh embodiments, specific examples are shown in which the cellular communication system 10 is EPS, UMTS, or CDMA2000. However, the application destinations of the first to seventh embodiments are not limited to EPS, UMTS, and CDMA2000 cellular communication systems. That is, the first to seventh embodiments can be widely applied to cellular communication systems in which traffic information is distributed by cell broadcast to a plurality of mobile stations.

  In addition, the processing of the broadcast distribution server 100, the control node 110, the base station 120, the communication terminal 200, or the traffic information server 300 related to the broadcast distribution of traffic information described in the first to seventh embodiments is at least one You may implement | achieve by making a computer system containing a processor (eg microprocessor, MPU (Micro Processing Unit), DSP (Digital Signal Processor)) run a program. Specifically, one or a plurality of programs including an instruction group for causing a computer system to execute an algorithm described using a flowchart, a sequence diagram, and the like may be created, and the programs may be supplied to the computer.

  This program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  Furthermore, the above-described embodiment is merely an example relating to application of the technical idea obtained by the present inventors. That is, the technical idea is not limited to the above-described embodiment, and various changes can be made.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2012-228349 for which it applied on October 15, 2012, and takes in those the indications of all here.

DESCRIPTION OF SYMBOLS 1 Traffic information delivery system 10 Cellular communication system 100 Broadcast delivery server 110 Control node 120 Base station 130 Cell 200 Communication terminal 300 Traffic information server 310 Information collection system 500 Car 510 Road 520 Roadside sensor 530 RSU (Road-Side Unit)

Claims (46)

A cellular communication network configured to broadcast broadcast information using a downlink physical channel that can be received by a plurality of standby mobile stations;
A traffic information server configured to request the cellular communication network to broadcast traffic information within a distribution area;
A communication terminal arranged in an automobile and configured to receive the traffic information distributed as the broadcast information via the cellular communication network;
A traffic information distribution system.   The broadcast transmission information is transmitted in units of sectors, cells, multiple cells, or location registration areas by CBS (Cell Broadcast Service), ETWS (Earthquake and Tsunami Warning System), or BC-SMS (Broadcast Short Message Service). The traffic information distribution system according to claim 1.   The traffic information distribution system according to claim 1 or 2, wherein the traffic information server transmits a distribution request indicating the content of the traffic information and the distribution area to a distribution server arranged in the cellular communication network.   The traffic information distribution system according to any one of claims 1 to 3, wherein the traffic information server determines the content of the traffic information and the distribution area based on probe information collected from an automobile.   The traffic information distribution system according to claim 4, wherein the probe information is collected via an intelligent traffic system including a roadside wireless device installed around a road, the cellular communication network, or both.   In response to a request from the traffic information server, the cellular communication network broadcasts a first message based on the traffic information in a first cell group including at least one cell corresponding to the delivery area. And broadcasting a second message different from the first message in a second cell group including at least one cell located around the first cell group. The traffic information distribution system according to claim 1.   The traffic information distribution according to claim 6, wherein the second message prompts the communication terminal not to notify the user of first information corresponding to the traffic information received at the communication terminal via inter-vehicle communication. system.   The second message is received at the communication terminal via inter-vehicle communication and prompts the communication terminal not to transfer the first information corresponding to the traffic information to another communication terminal. The traffic information distribution system described.   The traffic information distribution system according to any one of claims 6 to 8, wherein the first and second cell groups are arranged along a road.   The communication terminal is prevented from repeatedly receiving the downlink physical channel for receiving the traffic information in the same cell, the same cell group, or the same location registration area as the cell that has received the traffic information. The traffic information distribution system according to any one of claims 1 to 9.   The said communication terminal suppresses repeatedly receiving the said downlink physical channel for reception of the said traffic information within the predetermined period after receiving the said traffic information. Traffic information distribution system described in 1.   The traffic information distribution according to any one of claims 1 to 11, wherein the communication terminal transmits second information corresponding to the traffic information to another communication terminal disposed in another vehicle by inter-vehicle communication. system.   When the traffic information has been received via the cellular communication network, the communication terminal receives third information corresponding to the traffic information received from another communication terminal via inter-vehicle communication. The traffic information distribution system according to any one of claims 1 to 12, wherein transfer to a communication terminal is suppressed.   The traffic information distribution system according to claim 1, wherein the communication terminal changes a report operation of probe information in response to receiving the traffic information.   The probe information reporting operation is changed by (a) starting reporting of the probe information, (b) stopping reporting of the probe information, and (c) changing the reporting period of the probe information. The traffic information distribution system according to claim 14, comprising at least one of   When the communication terminal receives both the traffic information via the cellular communication network and other traffic information via a roadside wireless device installed around the road, the other communication information is given priority. The traffic information distribution system according to any one of claims 1 to 15, which notifies a user.   When the communication terminal receives both the traffic information via the cellular communication network and other traffic information via a roadside wireless device installed around a road, the traffic via the cellular communication network The traffic information distribution system according to claim 1, wherein information is preferentially notified to a user.   The communication terminal is configured to transmit an acknowledgment indicating the reception status of the traffic information to the cellular communication network without changing to a communication state in which user data can be transmitted and received, in the standby state. The traffic information distribution system according to any one of claims 1 to 17.   The traffic information according to claim 18, wherein the cellular communication network or the traffic information server changes a distribution method of the traffic information according to reception status of the confirmation response from a plurality of communication terminals including the communication terminal. Distribution system.   The traffic information distribution method is changed by: (a) distributing the traffic information using an advanced traffic system including a roadside wireless device installed around the road; and (b) an inter-vehicle communication function of the communication terminal. Transferring the traffic information to another communication terminal using, and (c) changing the upper limit of the number of hops when transferring the traffic information to another communication terminal by the inter-vehicle communication function of the communication terminal, The traffic information distribution system according to claim 19, comprising at least one. A distribution server that receives a traffic information broadcast request from the traffic information server to the distribution area;
In the first cell group including at least one cell corresponding to the distribution area and communicating with the distribution server, the traffic information is broadcast using a downlink physical channel that can be received by a plurality of standby mobile stations. The network to deliver,
A cellular communication system comprising:   The traffic information is transmitted by sector, cell, multiple cells, or location registration area by CBS (Cell Broadcast Service), ETWS (Earthquake and Tsunami Warning System), or BC-SMS (Broadcast Short Message Service). The cellular communication system according to claim 21.   The cellular communication system according to claim 21 or 22, wherein the request indicates a content of the traffic information and the distribution area.   In response to a request from the traffic information server, the network broadcasts a first message based on the traffic information in the first cell group and is located around the first cell group. The cellular communication system according to any one of claims 21 to 23, wherein a second message different from the first message is broadcasted in a second cell group including at least one cell.   25. The cellular communication system according to claim 24, wherein the second message is received at a communication terminal via inter-vehicle communication and prompts the communication terminal not to notify a user of first information corresponding to the traffic information.   26. The second message according to claim 24 or 25, wherein the second message is received at a communication terminal via inter-vehicle communication and prompts the communication terminal not to transfer the first information corresponding to the traffic information to another communication terminal. Cellular communication system.   27. The cellular communication system according to any one of claims 24 to 26, wherein the first and second cell groups are arranged along a road. A cellular communication means for receiving traffic information broadcast from a cellular communication network in a downlink physical channel that can be received by a plurality of mobile stations in a standby state;
Notification means for notifying the user of the traffic information;
A communication terminal.   The cellular communication means repeatedly receives the downlink physical channel for receiving the traffic information in the same cell, in the same cell group, or in the same location registration area as the cell that has received the traffic information. The communication terminal according to claim 28, wherein the communication terminal is suppressed.   29. The communication terminal according to claim 28, wherein the cellular communication means suppresses repeated reception of the downlink physical channel for receiving the traffic information within a predetermined period after receiving the traffic information.   The communication terminal according to any one of claims 28 to 30, further comprising an inter-vehicle communication unit that transmits the first information corresponding to the traffic information to another communication terminal disposed in another automobile by inter-vehicle communication. . It further comprises vehicle-to-vehicle communication means,
The inter-vehicle communication means further receives second information corresponding to the traffic information received from another communication terminal via the inter-vehicle communication when the traffic information has been received via the cellular communication network. The communication terminal according to any one of claims 28 to 30, wherein transfer to the communication terminal is suppressed. A reporting means for reporting probe information;
The communication terminal according to any one of claims 28 to 32, wherein the reporting means changes a reporting operation of probe information in response to receiving the traffic information.   The probe information reporting operation is changed by (a) starting reporting of the probe information, (b) stopping reporting of the probe information, and (c) changing the reporting period of the probe information. 34. The communication terminal according to claim 33, comprising at least one of.   When the notification means receives both the traffic information via the cellular communication network and other traffic information via a roadside wireless device installed around the road, the other traffic information is given priority. The communication terminal according to any one of claims 28 to 34, which notifies a user.   The notification means receives the traffic via the cellular communication network when receiving both the traffic information via the cellular communication network and other traffic information via a roadside wireless device installed around the road. The communication terminal according to any one of claims 28 to 34, wherein information is preferentially notified to a user.   37. A transmission means for transmitting an acknowledgment indicating the reception status of the traffic information to the cellular communication network in the standby state without changing to a communication state in which user data can be transmitted and received. The communication terminal according to any one of the above. A determination means for determining a traffic information distribution area;
In order to broadcast the traffic information using a downlink physical channel that can be received by a plurality of mobile stations in a standby state in at least one cell corresponding to the distribution area, communication with a distribution server in a cellular communication network is possible. Communication means to
A traffic information server comprising:   The traffic information server according to claim 38, wherein the traffic information server determines the content of the traffic information and the distribution area based on probe information collected from an automobile.   40. The traffic information server according to claim 39, wherein the probe information is collected via an intelligent traffic system including a roadside wireless device installed around a road, the cellular communication network, or both.   41. The traffic information server according to claim 40, wherein the determination unit changes a distribution method of the traffic information according to reception status of confirmation responses from the plurality of mobile stations.   The traffic information distribution method is changed by: (a) distributing the traffic information using an intelligent traffic system including roadside radio devices installed around the road; and (b) a communication terminal as the mobile station. Transferring the traffic information to another communication terminal using the inter-vehicle communication function, and (c) changing the upper limit of the number of hops when the traffic information is transferred to another communication terminal by the inter-vehicle communication function of the communication terminal 42. The traffic information server according to claim 41, comprising at least one of: Receiving traffic information broadcast from a cellular communication network in a downlink physical channel that can be received by a plurality of mobile stations in a standby state, and notifying the user of the traffic information;
A method for controlling a communication terminal. Determining a traffic information distribution area, and broadcasting the traffic information using a downlink physical channel that can be received by a plurality of standby mobile stations in at least one cell corresponding to the distribution area; Communicating with a distribution server in a cellular communication network;
A method for controlling a traffic information server. A non-transitory computer-readable medium storing a program for causing a computer to perform a communication terminal control method,
The method
Receiving traffic information broadcast from a cellular communication network in a downlink physical channel that can be received by a plurality of mobile stations in a standby state, and notifying the user of the traffic information;
A computer readable medium comprising: A non-transitory computer-readable medium storing a program for causing a computer to perform a traffic information server control method,
The method
Determining a traffic information distribution area, and broadcasting the traffic information using a downlink physical channel that can be received by a plurality of standby mobile stations in at least one cell corresponding to the distribution area; Communicating with a distribution server in a cellular communication network;
A computer readable medium comprising:

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