JP2001235335A - Map data transmission device, map data relay station, map data transmission system and method there for, method of transmitting and relaying map data, computer- readable recording medium having recorded program for causing computer to execute map data transmission method, and computer-readable recording medium having recorded program for causing computer to execute map data transmission and relay method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize flexible transmission of map data in accordance with the real-time property of the map data. SOLUTION: A transmission area selecting section 7 selects a map area to be transmitted to a mobile terminal, according to the current location, moving speed and the like of the mobile terminal, and a precedence setting section 11 provides the order of precedence of transmission to map parts constituting the selected map area, and a time datecting section 12 detects for each of the map parts the scheduled time of display at which the mobile terminal should display each of the map parts. A transmission schedule setting section 13 sets whether or not there are a transmission schedule and the guarantee of re-transmission for each of the map parts, according to the order of precedence set for the map parts and the detected scheduled time. A packet generating section 14 stores the map parts in respective packets and a packet transmitting section 15 transmits the packets in a connection-less fashion. When a packet loss or the like occurs as to the packet for which re-transmission is ensured, a re-transmission process is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a map information distribution device, a map information distribution method, a map information distribution system, and a recording medium for distributing the map information to a plurality of mobile terminals via wireless communication.

[0002]

2. Description of the Related Art FIG.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram of a conventional deformed map creating apparatus disclosed in Japanese Patent No. 4042 and a map information providing system using the same. This deformed map creating apparatus is a vector map data 1 having information on the shape of a target and a road.
01 is associated with a nearby road where the target is located, and the target linking means 106 that enables the movement of the target information along with the movement of the road; and the map data linked by the target linking means. It is provided with deformation processing means 107 to 112 for performing a deformation process, and since the target is associated with the road, the relationship between the target and the road can be maintained even when the map shape is deformed. It is like that.

In this deformed map creating apparatus, as a deforming processing means, a route extracting means for extracting only an area along a searched route, a target surrounding shaping means for extending a length of a road so that the target does not overlap, Shaping means other than around the target that thins out data of roads that are not related to the target, angle correction means that deforms the angle at which the line intersects, and an intersection that moves to the intersection of the mesh in which the constituent points of the line are superimposed on the vector map Moving means, a line segment, a linear approximation means for approximating a straight line connecting intersections of the line segment and a mesh superimposed on the vector map, a map area setting means for dynamically determining a map cutout area according to the number of target objects, Road omitting means for omitting road areas smaller than a certain size, straight-line approximation means using intersection angles that approximate two straight lines with small intersection angles as straight lines, Road shortening unit and target on the map is provided a target object thinning means for thinning the target so as not to overlap to. The deformed map creation device deforms the road associated with the target narrowed down to the area along the searched route, taking into account the relative positional relationship and visibility rather than positional accuracy, Roads that are not associated with objects are thinned out and simplified. When the targets overlap, the targets are thinned according to the display priority so that the displays of the targets do not overlap.

Further, this map information providing system provides a map information providing system using a small and lightweight portable terminal device having a wireless communication function and an information providing device providing map information in response to a search request from the portable terminal device. The information providing device automatically configures an information storage area for storing map information, a search means for searching necessary information from the information storage area, and a simplified deformed map from the map information searched by the search means. A deforming map creating device to be created, communication means for wirelessly communicating with the portable terminal device, and a search request passed through the communication means are analyzed to generate a search instruction sequence for the search means, and the search means The retrieved map information is passed to the deformed map creator, and the deformed map created by the deformed map creator is transmitted via the communication means. It is constituted by a search control means for transmitting the band terminal.

[0005] This map information providing system reduces the amount of data by deforming the map. 1) It is possible to display an easy-to-view map even on a small portable terminal having a small screen display size, memory capacity, disk capacity, and the like. Also,
2) Even if an unstable wireless communication function with low performance is used, map information can be easily distributed to a portable terminal.

Prior art 2. Also, FIG.
FIG. 1 is a functional block diagram of a drawing data management device having a conventional hierarchical data structure disclosed in Japanese Unexamined Patent Publication No. -120330.

In this drawing data management apparatus, in the management of drawing data in which each figure in a drawing is divided into layers and the drawings of each layer are superimposed and displayed, the layers are determined based on attribute information attached to each figure data. By classifying and changing the attribute information, it is possible to easily and quickly change the hierarchy of the graphic having the attribute information to the hierarchy corresponding to the changed attribute information.

Prior art 3. Further, FIG.
FIG. 1 is a sequence diagram of a packet transmission method when a conventional map data is transmitted from a server to a mobile terminal disclosed in JP-A-300499, that is, a diagram showing a communication procedure performed between an in-vehicle terminal and a server. As shown in FIG. 32, the in-vehicle terminal transmits one byte at a time to the server side with one byte as one block. On the other hand, the buffer and the data are received one byte at a time, and when one packet of data is received, ACK or NAK is returned to the in-vehicle terminal. Here, ACK is a signal indicating reception success, and NAK is a signal indicating reception failure. When the ACK is returned from the server side, the in-vehicle terminal determines that the transmitted one packet has been received by the server, and determines the next one packet.
Send a packet. On the other hand, if NAK is returned, it is determined that the transmitted one packet was not received by the server, and the one packet is retransmitted. The server performs a route search in accordance with the search condition data transmitted from the vehicle-mounted terminal as described above, and extracts information related to the obtained route (hereinafter, route-related information) from the database. , Along with the route. Next, the vehicle-mounted terminal receives the route-related information transmitted from the server. The route-related information is composed of a plurality of packets. Each packet includes route data,
One of map data, traffic information data, weather information data, and event information data is included. Each packet is STX, packet No. , Total number of packets, packet type, data entity, ETX, and checksum. STX is a flag indicating the start of data, and is represented here by 1 byte. The total number of packets indicates the total number of packets to be transmitted, and is represented here by one byte. The packet No. Is an identifier indicating the order of the packet in all the packets, and is represented by 1 byte here. The packet type is an identifier indicating the type of the data entity included in the packet, and is represented here by 1 byte. In this embodiment, route data, map data, traffic information, weather information, and event information are selected as packet types. ETX is a flag indicating the end of data,
Here, it is represented by one byte. The checksum is used for correcting errors in the vehicle-mounted terminal, and includes STX, packet No. , The total number of packets, the packet type, the data entity, the ETX, and the sum of the data sizes of the checksum itself, and are expressed in 2 bytes here.

The processing procedure for receiving the path-related information will be described below in detail with reference to FIG. Note that, unlike the above-described search condition data transmission procedure, the transmission side in FIG. 32 is a server, and the reception side is an in-vehicle terminal. As shown in FIG.
The in-vehicle terminal receives the path-related information one block at a time using one byte as one block. Then, the sizes of the received blocks are sequentially added, and E indicating the end of data is added.
The value is compared with the checksum value transmitted after TX. If the data size obtained by the addition matches the checksum value as a result of the comparison, ACK is sent to the server.
Is returned to wait for the next packet to be received. on the other hand,
If they do not match, it returns a NAK to the server and requests retransmission of the same packet. As described above, the reception of all the packets constituting the route related information is completed. As described above, according to the basic method of transmitting and receiving map data described in the patent publication, one packet is divided into one block with one byte as one block and transmitted. After receiving this data, it is determined whether or not the packet has been normally received. If the packet is normal, ACK is returned to the transmission source, and if the packet is error, NAK is returned to the transmission source. After transmitting a packet, the transmission source puts the transmission process on hold and waits for reception of a signal until an ACK or NAK is received. When the ACK is received, the next packet is transmitted. When the NAK is received, the packet is retransmitted. Processing is performed. That is, the map data transmission / reception system described in the patent publication is a system in which a retransmission request is always issued every time a packet loss or a packet bit error occurs, and retransmission is repeated until complete data is received. It is.

Prior art 4. FIG. 33 is a diagram showing processing in a conventional relay station. Reference numeral 200 in the figure denotes a conventional relay station. The cells in the figure are packets storing data. The symbols A, B, and C in the packets indicate the importance of each packet, and the importance is higher in the order of A, B, and C. FIG. 33 shows a situation in which relay station 200 relays a packet when a packet is transmitted from a transmitting device on the left side to a receiving device on the right side. Normally, the relay station is configured as shown in FIG.
As shown in (a), all packets transmitted from the map transmitting device are transferred as they are. However, when the congestion increases, a process for discarding the packet transmitted by the relay station is performed. Here, a conventional relay station mechanically discards a packet without considering the importance of each packet.

[0011]

In the deformed map creating apparatus / map information providing system of the prior art 1 as described above, 1) When the communication infrastructure (communication medium) used for distributing the map is changed, Since the performance / characteristics of the communication media, that is, the communication speed and the communication band are different, the amount of data that can be transmitted per unit time is different for each communication medium. For this reason, there has been a problem that it is not possible to create / change a deformed map dynamically adapted to the performance of such communication media. 2) In addition, since the map cannot be deformed in consideration of the dynamic congestion state of the communication medium, when the wireless / wired network is congested, the network throughput is significantly reduced. For this reason, there is a problem that the map distribution service is hindered, for example, the map distribution speed is significantly reduced. In addition, when a map deformation in consideration of network congestion is created in advance, it is not possible to make a change such as dynamically increasing the degree of detail of a displayed map even when the network traffic is small, so that user satisfaction cannot be obtained. There was a problem. 3) Further, since map data is delivered via a communication path having a low communication speed and a narrow communication band, there is a problem that a large amount of map data cannot be efficiently transferred.

Further, in the prior art 2, according to the phase in which the map information is used, the hierarchical division is changed, re-mapped to a different hierarchical structure, and further, each layer is provided with attribute information. In order to realize such a usage that changes the handling of each layer, the processing becomes complicated, and the processing speed is remarkably deteriorated.

In the technique of the prior art 3, after transmitting a packet, the transmitting side puts the transmission process in a pending state and waits for reception of a signal until an ACK or NAK is received. When the ACK is received, the next packet is transmitted. Send, NA
When K is received, a packet retransmission process is performed. There is a problem in that the transmission processing of the next transmission packet cannot be started unless a reception confirmation signal is received even though the transmission processing of one packet has been completed. As the network becomes more congested, the time required to receive the acknowledgment signal becomes longer. Retransmission is repeated until a normal packet is received. Therefore, there is a problem that it takes much time to transmit a large amount of data. Furthermore, when the network becomes congested, the number of packets transmitted per unit time is significantly reduced. When real-time data transmission is required,
There is a problem that it hinders the provision of services. Further, in the method of the related art 3, since data is transmitted and received after a communication line connection is established between the mobile terminal and the server, data transfer via wireless communication in which the line connection is frequently disconnected is performed. In such a case, every time the line is disconnected, a connection process with the server must be performed to establish the line connection. In addition, the number of servers that can be connected for communication with mobile terminals is limited by the resource environment such as operating system resources and the number of servers, so that it is difficult for many users to use the map distribution service at the same time. There is. According to the technique of the prior art 3, packets are received in the order of packet No.
It may not be necessary to reconstruct the map data in the order of o.
In this case, processing for receiving packets in the order of packet numbers becomes an overhead. The basic method of transmitting and receiving map data is a method in which a retransmission request is always issued every time a packet loss or packet bit error occurs, and retransmission is repeated until complete data is received. In particular, when the storable data size of the received map data of the mobile terminal is small, the real-time property required for map distribution is further increased, so that it is difficult to cope with the above conventional method.

According to the technique of the prior art 4, when a process of discarding a packet transmitted by a relay station is performed when congestion occurs,
The packet was mechanically discarded without considering the importance of each packet. Therefore, as shown in FIG. 33 (b), there is a situation where A and B with high importance are discarded, and only C with least importance is transferred. In this case, the client cannot receive the more important A and B packets, and has to make a retransmission request for the A and B packets.

The present invention has been made to solve such a problem, and has instability in communication such as interruption of more detailed map data at a slow communication speed, a narrow communication band, and the like. It is an object of the present invention to obtain a map information distribution device, a map information distribution method, and a recording medium that can be efficiently distributed to mobile terminals even through wireless communication.

[0016]

A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein the map data transmitting apparatus has a display unit for displaying the map data. A map data transmitting device for transmitting the map data to the device,
A transmission schedule setting unit that sets a transmission schedule for transmitting the map data to the map data receiving device;
A display scheduled time detecting unit that detects a scheduled display time, which is a time at which the map data receiving device starts displaying the map data on the display unit, wherein the transmission schedule setting unit detects the scheduled display time The transmission schedule is set based on the scheduled display time detected by the section.

The map data transmitting apparatus further includes a transmission order priority setting section for setting a priority of the transmission order of the map data, wherein the transmission schedule setting section is detected by the display scheduled time detecting section. The transmission schedule is set based on the scheduled display time and the transmission order priority set by the transmission order priority setting unit.

The map data transmitting apparatus further includes a division criterion setting unit for setting a division criterion for dividing the map data into a plurality of groups. The map data is divided into a plurality of groups based on the set division criteria, and the transmission schedule setting unit sets the transmission schedule for each of the groups.

The division criterion setting unit dynamically changes the division criterion, and the transmission schedule setting unit converts the map data into a plurality of maps based on the classification criterion dynamically changed by the division criterion setting unit. It is characterized by being divided into groups.

The map data transmitting apparatus further has a transmission order priority setting section for setting a priority of the transmission order of the map data, and the division criterion setting section is set by the transmission order priority setting section. The classification criterion is set based on the determined transmission order priority.

[0021] The transmission schedule setting section always stores the map data in the case where the map data receiving device does not receive the map data normally and the map data which is not normally received by the map data receiving device. A retransmission guarantee data group that guarantees retransmission to the map data receiving device, and the map that is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. The data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission of the data to the map data receiving apparatus.

In a map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data,
A transmission schedule setting unit that sets a transmission schedule for transmitting the map data to the map data receiving device; and a transmission deadline for detecting a transmission deadline for transmitting the map data to the map data receiving device. A transmission schedule setting unit configured to set the transmission schedule based on the transmission deadline detected by the transmission deadline detection unit.

The map data transmitting device is a map data transmitting device for transmitting map data to a map data receiving device having a display unit for displaying the map data, and the map data transmitting device further comprises the map data receiving device The apparatus has a scheduled display time detecting unit that detects a scheduled display time when the display of the map data is started on the display unit, and the transmission deadline detecting unit includes a scheduled display time detected by the scheduled display time detecting unit. The transmission deadline is detected based on

[0024] The map data transmitting apparatus further includes a transmission order priority setting unit for setting a priority of the transmission order of the map data, and the transmission schedule setting unit detects the priority of the transmission order of the map data. The transmission schedule is set based on the transmission time limit and the transmission order priority set by the transmission order priority setting unit.

The map data transmitting apparatus further includes a transmission processing completion time detecting unit for detecting a transmission processing completion time when the map data transmission processing is to be completed, and the transmission schedule setting unit. Compares the transmission time limit detected by the transmission time limit detection unit with the transmission processing completion time detected by the transmission processing completion time detection unit, and compares the transmission time limit with the transmission processing completion time The transmission schedule is set based on the comparison.

[0026] The transmission schedule setting section always stores the map data in the case where the map data receiving device does not receive the map data normally and the map data which is not normally received by the map data receiving device. A retransmission guarantee data group that guarantees retransmission to the map data receiving device, and the map that is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. The data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission to the map data receiving apparatus, and the transmission schedule is set for each of the retransmission guaranteed data group and the retransmission non-guaranteed data group.

[0027] The map data transmitting apparatus further includes a transmission order priority setting section for setting a priority of the transmission order of the map data, and the transmission schedule setting section is set by the transmission order priority setting section. The map data is divided into the retransmission guaranteed data group and the retransmission non-guaranteed data group based on the determined transmission order priority.

The map data transmitting apparatus further includes a transmission processing completion time detecting unit for detecting a transmission processing completion time when the map data transmission processing is to be completed, and the transmission schedule setting unit. Compares the transmission time limit detected by the transmission time limit detection unit with the scheduled transmission processing completion time detected by the scheduled transmission processing time detection unit, and completes the transmission process earlier than the transmission time limit The map data having a scheduled time is divided into the retransmission guarantee data group, and the map data having the scheduled transmission processing completion time at a time later than the transmission deadline is divided into the retransmission non-guaranteed data group. I do.

The map data transmitting apparatus further includes a transmission processing completion time detection unit that detects a transmission processing completion time when the map data transmission processing is to be completed,
A transmission processing end time detection unit that detects a transmission processing end time for ending the transmission processing of the map data, wherein the transmission schedule setting unit detects the transmission processing completion time detected by the transmission processing completion time detection unit; Comparing the time with the transmission processing end time detected by the transmission processing end time detection unit, and setting the transmission schedule based on the comparison between the transmission processing completion time and the transmission processing end time. I do.

The transmission schedule setting section compares the transmission processing completion time detected by the transmission processing completion time detection section with the transmission processing end time detected by the transmission processing end time detection section, The transmission schedule is set only for the map data having a scheduled transmission processing completion time earlier than the transmission processing end time.

The transmission schedule setting section compares the transmission processing completion time detected by the transmission processing completion time detecting section with the transmission processing ending time detected by the transmission processing ending time detecting section, A transmission schedule for transmitting map data having a scheduled transmission processing completion time later than the transmission processing end time after the transmission end time has elapsed is set.

[0032] The map data receiving apparatus is a map data transmitting apparatus for transmitting map data to a map data receiving apparatus having a display unit for displaying the map data. The map data transmitting apparatus further comprises a map data receiving apparatus. The apparatus has a display end time detecting unit that detects a display end time, which is a time when the display of the map data on the display unit ends,
The transmission processing end time detection unit detects the transmission processing end time based on the display end time detected by the display end time.

[0033] The transmission schedule setting section dynamically changes the timing for setting the transmission schedule based on the data amount of map data to be transmitted to the map data receiving device.

[0034] The map data transmitting device further includes a congestion status detecting unit for detecting a congestion status of a communication path used by the map data transmitting device for transmitting the map data; A transmission schedule adjusting unit that resets a transmission schedule of the map data set by the transmission schedule setting unit.

In a map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data,
The map data transmitting apparatus has a plurality of communication paths used by the map data transmitting apparatus for transmitting the map data, and the map data transmitting apparatus includes a congestion state detecting unit that detects a congestion state of the communication path. A communication path setting switching unit that dynamically sets the communication path used for transmitting the map data from a plurality of communication paths based on the congestion state detected by the congestion state detection unit. .

[0036] The communication path setting switching section sets the communication path used for transmitting the map data from a plurality of the communication paths for each of the map data.

In a map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data,
A transmission schedule setting unit that sets a transmission schedule for transmitting the map data to the map data receiving device;
A packet generation unit configured to generate a data delivery packet storing the map data according to the transmission schedule set by the transmission schedule setting unit; and setting the data delivery packet generated by the packet generation unit by the transmission schedule setting unit And a packet transmitting unit that transmits the data to the map data receiving device according to the transmitted transmission schedule.

When the map data receiving device does not normally receive the data delivery packet, the packet transmitting unit transmits the data delivery packet that has not been normally received by the map data receiving device to the map data receiving device. Is retransmitted to

When the map data receiving apparatus does not normally receive the data delivery packet, the packet generating unit always receives the data delivery packet that has not been normally received by the map data receiving apparatus. A retransmission guarantee packet that guarantees retransmission to the device, and the data delivery packet that was not normally received by the map data receiving device when the map data receiving device did not normally receive the data delivery packet. Generating a retransmission non-guaranteed packet that does not guarantee retransmission to the map data receiving device, wherein the packet transmitting unit starts transmitting the retransmission non-guaranteed packet after the transmission of the retransmission assurance packet is completed. And

[0040] The packet transmission unit starts transmission of the retransmission non-guaranteed packet after retransmission of the retransmission guarantee packet is completed.

[0041] The packet transmission unit transmits the data delivery packet without establishing a connection with the map data receiving device.

The packet transmitting unit transmits the data delivery packet without establishing a connection with the map data receiving device, and establishes a connection with the map data receiving device to transmit the data delivery packet. It is characterized in that any of the transmission methods for transmitting the delivery packet can be selected.

The map data transmitting apparatus further includes a transmission order priority setting section for setting a priority of the transmission order of the map data, and the packet generation section is set by the transmission order priority setting section. Set the transmission order priority to the data delivery packet, the packet transmitting unit,
The data delivery packet is retransmitted based on the transmission order priority set in the data delivery packet.

[0044] The map data transmitting device may further include a retransmission indicating the frequency at which the packet transmitting unit retransmits the data delivery packet with respect to the number of times the map data receiving device did not normally receive the data delivery packet. A retransmission level setting unit for setting a level to the data delivery packet, wherein the packet transmission unit retransmits the data delivery packet based on the retransmission level set for the data delivery packet by the retransmission level setting unit. It is characterized by performing.

[0045] The map data transmitting apparatus further includes a transmission order priority setting unit for setting a priority of the transmission order of the map data, and the retransmission level setting unit is set by the transmission order priority setting unit. The retransmission level is set in the data delivery packet based on the determined transmission order priority.

The packet generator assigns a sequence number indicating the transmission order of the data delivery packet to the data delivery packet. A sequence number notification packet for notifying the map data receiving apparatus of a retransmission non-guaranteed sequence number assigned to the non-guaranteed packet is generated.

[0047] The packet generation unit generates a sequence number notification packet for notifying the retransmission guarantee sequence number given to the retransmission guarantee packet to the map data receiving device.

[0048] The packet generation unit is operable to provide a sequence number notification packet for notifying the map data receiving apparatus of a sequence number assigned to a data transmission packet transmitted first, and that the transmission of a retransmission guarantee packet has been completed. A retransmission guarantee packet transmission end notification packet notifying the data receiving device and a retransmission non-guaranteed packet transmission end notification packet notifying the map data receiving device that the retransmission non-guaranteed packet has been transmitted are generated. I do.

[0049] The map data transmitting apparatus further includes a packet transmitting section for transmitting the data delivery packet generated by the packet generating section, and the packet transmitting section transmits the sequence number notification to the map data receiving apparatus. A packet is transmitted, and the data delivery packet is transmitted after the map data receiving device receives the sequence number notification packet.

[0050] The packet generator generates the data delivery packet storing the map data and an identifier indicating the identity of the map data.

In a map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data,
A transmission reliability priority setting unit configured to set a transmission reliability priority of the map data to the map data; and a packet generation unit configured to generate a data delivery packet storing the map data. The unit includes a composite packet generation unit that generates a composite data delivery packet storing a plurality of map data in which the transmission reliability priorities different by the transmission reliability priority setting unit are stored.

The composite packet generator stores the map data set with the higher transmission reliability priority at the beginning of the composite data delivery packet, and stores the map data set with the lower transmission reliability priority. The map data is stored at the end of the composite data delivery packet.

In a map data transmitting system having a map data transmitting device for transmitting a data delivery packet storing map data to a map data receiving device, and a map data relay station for relaying the transmission of the data delivery packet,
The map data transmitting device may further include: a transmission reliability priority setting unit configured to set the transmission reliability priority of the map data to the map data; and the transmission reliability priority different by the transmission reliability priority setting unit. A composite packet generation unit that generates a composite data delivery packet that stores a plurality of map data whose degrees are set, wherein the map data relay station has a packet discard unit that discards the data delivery packet,
The packet discarding unit preferentially discards, from among the plurality of map data stored in the composite data delivery packet, map data set to have a lower transmission reliability priority than other map data. And

The composite packet generator stores the map data set with the higher transmission reliability priority at the beginning of the composite data delivery packet, and stores the map data set with the lower transmission reliability priority. The map data is stored at the end of the composite data delivery packet, and the packet discarding unit of the map data relay station is located at the end of the composite data delivery packet among the plurality of map data stored in the composite data delivery packet. The stored map data is preferentially discarded.

In a map data transmitting system having a map data transmitting device for transmitting a data delivery packet storing map data to a map data receiving device, and a map data relay station for relaying the transmission of the data delivery packet,
The map data transmitting device, when the map data receiving device did not normally receive the data delivery packet, the map data receiving device is not normally received the data delivery packet received by the map data receiving device always the map data receiving device A retransmission guarantee packet for guaranteeing retransmission, and the data delivery packet that was not normally received by the map data receiving device when the map data receiving device did not receive the data delivery packet normally. A retransmission non-guaranteed packet that does not guarantee retransmission to the receiving device is transmitted to the map data relay station, and the map data relay station relays the retransmission assurance packet in preference to the retransmission non-guaranteed packet. And

In a map data relay station for relaying the transmission of a data delivery packet storing map data, a buffer unit for temporarily storing the data delivery packet, and the data delivery packet temporarily stored by the buffer unit A packet discarding unit that discards the data delivery packet that is a ratio of discarding of the data delivery packet discarded by the packet discarding unit to all the data delivery packets temporarily stored in the buffer unit. And a discard rate setting unit.

In a map data transmitting system having a map data transmitting device for transmitting a data delivery packet storing map data to a map data receiving device, and a map data relay station for relaying the transmission of the data delivery packet,
The map data transmission device, a transmission reliability priority setting unit that sets the transmission reliability priority of the map data to the map data, and a transmission reliability priority set by the transmission reliability priority setting unit A packet generating unit that generates the data delivery packet storing the set map data, wherein the map data relay station includes a buffer unit that temporarily stores the data delivery packet, and a buffer unit that temporarily stores the data delivery packet. A packet discarding unit for discarding the temporarily stored data delivery packet, and a discarding of the data delivery packet discarded by the packet discarding unit for all the data delivery packets temporarily stored in the buffer unit. A packet discard rate setting unit for setting a packet discard rate as a ratio, wherein the map data relay station discards the packet. Setting unit, and sets the transmission reliability priority the packet discard rate based on the reliability of priority set the transmission to the map data by the setting unit of the map data transmission device.

The map data relay station may further include a ratio of a free data amount of the buffer unit in which the data delivery packet is not stored to a maximum data amount of the buffer unit in which the buffer unit can store the data delivery packet. A buffer vacancy rate detection unit that detects a certain buffer vacancy rate, wherein the packet discard rate adjustment unit uses the buffer vacancy rate detected by the buffer vacancy rate detection unit and the transmission reliability priority setting unit to generate the map. A packet discard rate adjustment unit that adjusts a discard rate of the data delivery packet based on the transmission reliability priority set in data.

In a map data transmitting method for transmitting map data to a map data receiving apparatus for receiving map data,
A transmission map data selecting step of selecting map data to be transmitted to the map data receiving device from the map data,
A transmission schedule setting step of setting a transmission schedule for transmitting the map data selected in the transmission map data selection step to the map data receiving device; and transmitting the map data in accordance with the transmission schedule set in the transmission schedule setting step. A packet generating step for generating the stored data delivery packet and a packet transmitting step for transmitting the data delivery packet generated in the packet generating step are provided.

The map data transmitting method is a map data transmitting method for transmitting map data to a moving map data receiving device which is a moving object, and the transmitting map data selecting step includes the step of selecting a current position of the moving map data receiving device. The map data to be transmitted to the moving map data receiving device is selected based on a moving speed of the moving map data receiving device.

[0061] The map data transmitting method is a map data transmitting method for transmitting map data to a map data receiving device having a display unit for displaying the map data. The map data transmitting method further comprises the map data receiving method. The apparatus further includes a scheduled display time detecting step of detecting a scheduled display time, which is a time when the apparatus starts displaying the map data on the display unit, and the transmission schedule setting step detects the scheduled display time by the scheduled display time detecting step. The transmission schedule is set based on the displayed scheduled display time.

The map data transmission method further includes a transmission order priority setting step of setting a priority of the transmission order of the map data, wherein the transmission schedule setting step is detected by the display scheduled time detection step. The transmission schedule is set based on the scheduled display time and the transmission order priority set in the transmission order priority setting step.

In the transmitting schedule setting step, when the map data receiving device does not normally receive the map data, the map data receiving device does not always receive the map data that has not been normally received by the map data receiving device. A retransmission guarantee data group that guarantees retransmission to the map data receiving device, and the map that is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. The data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission of the data to the map data receiving apparatus.

The map data transmitting method further includes a transmission deadline detecting step of detecting a transmission deadline for transmitting the map data to the map data receiving device, wherein the transmission schedule setting step includes the transmission deadline detecting step. The transmission schedule is set based on the transmission time limit detected by (1).

The map data transmission method further includes a transmission processing completion time detecting step of detecting a transmission processing completion time when the map data transmission processing is scheduled to be completed, and the map data transmission processing. A transmission processing end time detection step of detecting a transmission processing end time to be ended, wherein the transmission schedule setting step includes the transmission processing completion time detected by the transmission processing completion time detection step and the transmission processing end time The transmission processing end time detected by the timing detection step is compared, and the transmission schedule is set based on a comparison between the transmission processing completion time and the transmission processing end time.

[0066] The packet transmitting step transmits the data delivery packet without establishing a connection with the map data receiving device.

In the packet generating step, a sequence number indicating a transmission order of the data delivery packet is added to the data delivery packet. In the packet generating step, the map data receiving device normally receives the data delivery packet. A retransmission assurance sequence number assigned to a retransmission assurance packet that guarantees that the data delivery packet that was not normally received by the map data receiving device if not, is always retransmitted to the map data receiving device; A retransmission non-guaranteed packet that does not guarantee retransmission of the data delivery packet that was not normally received by the map data receiving device to the map data receiving device when the receiving device did not receive the data delivery packet normally. The assigned retransmission non-guaranteed sequence number and the map data And generates a sequence number notification packet for notifying the communication apparatus.

A map data transmission method for transmitting a data delivery packet storing map data to a map data receiving apparatus, and a map data relay method for relaying the transmission of the data delivery packet, wherein The map data transmission method includes: a transmission reliability priority setting step of setting a transmission reliability priority of the map data to the map data; and the transmission reliability priority different by the transmission reliability priority setting step Generating a composite data delivery packet storing a plurality of map data in which the map data is set, wherein the map data relay method includes a packet discarding step of discarding the data delivery packet, The discarding step includes the step of discarding the plurality of map data stored in the composite data delivery packet. Among other transmission reliability priority than map data and discards preferentially from the set map data low.

The composite packet generating step of the map data transmitting method includes: storing the map data set with a high transmission reliability priority at the beginning of the composite data delivery packet; Is stored at the end of the composite data delivery packet, and the packet discarding step of the map data relay method includes the step of storing the composite data out of the plurality of map data stored in the composite data delivery packet. It is characterized by being preferentially discarded from the map data stored at the end of the data delivery packet.

A computer-readable medium having recorded thereon a program for causing a computer to execute a map data transmitting method for transmitting map data to a map data receiving device for receiving map data, wherein the data transmitting method comprises: A transmission map data selecting step of selecting map data to be transmitted to the data receiving device from the map data, and a transmission setting a transmission schedule for transmitting the map data selected in the transmission map data selecting step to the map data receiving device. A schedule setting step, a packet generation step of generating a data delivery packet storing the map data according to the transmission schedule set by the transmission schedule setting step, and the data delivery packet generated in the packet generation step. And having a packet transmitting step of transmitting Tsu bets.

The map data transmitting method is a map data transmitting method for transmitting map data to a moving map data receiving device, which is a moving object. The transmitting map data selecting step includes a step of selecting a current position of the moving map data receiving device. The map data to be transmitted to the moving map data receiving device is selected based on a moving speed of the moving map data receiving device.

The map data transmitting method is a map data transmitting method for transmitting map data to a map data receiving device having a display unit for displaying the map data. The map data transmitting method further includes the map data receiving method. A display scheduled time detecting step of detecting a display scheduled time, which is a time when the apparatus starts displaying the map data on the display unit, wherein the transmission schedule setting step detects the display scheduled time detecting step. The transmission schedule is set based on the displayed scheduled display time.

The map data transmitting method further includes a transmission order priority setting step of setting a priority of the transmission order of the map data, wherein the transmission schedule setting step is detected by the display scheduled time detecting step. The transmission schedule is set based on the scheduled display time and the transmission order priority set in the transmission order priority setting step.

[0074] The transmitting schedule setting step includes the step of, when the map data receiving device does not receive the map data normally, always transmitting the map data that has not been normally received by the map data receiving device. A retransmission guarantee data group that guarantees retransmission to the map data receiving device, and the map that is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. The data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission of the data to the map data receiving apparatus.

The map data transmitting method further includes a transmission deadline detecting step of detecting a transmission deadline for transmitting the map data to the map data receiving device, and the transmission schedule setting step includes the transmission deadline detecting step. The transmission schedule is set based on the transmission time limit detected by the above.

The map data transmission method further includes a transmission processing completion time detecting step of detecting a transmission processing completion time when the map data transmission processing is scheduled to be completed, and the map data transmission processing. A transmission processing end time detection step of detecting a transmission processing end time to be ended, wherein the transmission schedule setting step includes the transmission processing completion time detected by the transmission processing completion time detection step and the transmission processing end time The transmission processing end time detected by the timing detection step is compared, and the transmission schedule is set based on a comparison between the transmission processing completion time and the transmission processing end time.

[0077] In the packet transmitting step, the data delivery packet is transmitted without establishing a connection with the map data receiving device.

In the packet generating step, a sequence number indicating a transmission order of the data delivery packet is added to the data delivery packet. In the packet generating step, the map data receiving apparatus normally receives the data delivery packet. A retransmission assurance sequence number assigned to a retransmission assurance packet that guarantees that the data delivery packet that was not normally received by the map data receiving device if not, is always retransmitted to the map data receiving device; A retransmission non-guaranteed packet that does not guarantee retransmission of the data delivery packet that was not normally received by the map data receiving device to the map data receiving device when the receiving device did not receive the data delivery packet normally. The assigned retransmission non-guaranteed sequence number and the map data And generates a sequence number notification packet for notifying the communication apparatus.

A map data transmission method for transmitting a data delivery packet storing map data to a map data receiving apparatus, and a map data relay method for relaying the transmission of the data delivery packet, to a computer. A computer-readable medium storing a program to be executed, wherein the map data transmission method includes a transmission reliability priority setting step of setting a transmission reliability priority of the map data to the map data. A composite packet generating step of generating a composite data delivery packet storing a plurality of map data in which the transmission reliability priorities different by the transmission reliability priority setting step are set, the method comprising: Has a packet discarding step of discarding the data delivery packet, The packet discarding step is characterized by preferentially discarding, from among the plurality of map data stored in the composite data delivery packet, map data set to have a lower transmission reliability priority than other map data. I do.

The composite packet generating step stores the map data set with the higher transmission reliability priority at the head of the composite data delivery packet, and stores the map data with the transmission reliability priority set lower. Storing the map data at the end of the composite data delivery packet, wherein the packet discarding step of the map data relaying method includes, at the end of the composite data delivery packet among the plurality of map data stored in the composite data delivery packet, The stored map data is preferentially discarded.

The map data transmitting device of the map data transmitting method is a map data transmitting device for transmitting map data to a moving map data receiving device which is a moving object, and the map data transmitting device further comprises: A moving status information receiving unit that receives, from the moving map data receiving device, moving status information that is information relating to the movement of the data receiving device, and the display scheduled time detecting unit includes the moving schedule information receiving unit that receives The display scheduled time is detected based on the movement status information.

The transmission schedule setting section sets the transmission schedule based on the scheduled display time detected by the scheduled display time detecting section and the transmission order priority set by the transmission order priority setting section, and It is characterized in that the setting of the transmission schedule based on the transmission order priority set by the transmission order priority setting unit is dynamically switched.

The map data transmitting device is a map data transmitting device for transmitting the map data to a map data receiving device having a display unit for displaying the map data. The map data transmitting device further comprises the map data transmitting device. A display unit pixel number detection unit that detects the number of unit pixels forming the display unit of the receiving device; and a display unit based on the number of unit pixels of the display unit detected by the display unit pixel number detection unit. A display density detection unit that detects a display density that is a data amount per unit pixel of the map data to be transmitted, and the transmission order priority setting unit is configured based on the display density detected by the display density detection unit. The transmission order of the map data is set.

The map data transmitting device is a map data transmitting device for transmitting the map data to a map data receiving device having a display unit for displaying the map data, and the map data transmitting device further comprises the map data transmitting device. A display unit pixel number detection unit for detecting the number of unit pixels constituting the display unit of the receiving device, and displaying on the display unit based on the number of unit pixels of the display unit detected by the display unit pixel number detection unit A display density detecting unit for detecting a display density which is a data amount per unit pixel of the map data to be displayed, and displaying on the display unit based on a display density per unit pixel of the display unit detected by the display density detecting unit. An allocation unit pixel number detection unit that detects the number of unit pixels allocated to the map data to be processed, and the map data transmission device transmits the map data as the map data. A required unit pixel number detecting unit for detecting the unit pixel number necessary to display the map data on the display unit, wherein the transmission order priority setting unit detects the unit pixel number detected by the allocated unit pixel number detecting unit. A priority for setting the transmission order of the map data is set based on the allocated unit pixel number and the required unit pixel number detected by the required unit pixel number detecting unit.

The display density detecting section divides the display section into portions where the display densities are approximated, and calculates a display data amount per unit pixel of the map data displayed in the divided portions of the display section. An average display density detection unit that detects an average display density for each of the divided parts of the display unit, and the transmission order priority setting unit is based on the average display density detected by the average display density detection unit. The transmission order of the map data is set.

In a map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data,
A transmission map data selection unit that selects map data to be transmitted to the map data reception device from the map data, and a transmission schedule setting unit that sets a transmission schedule for transmitting the map data selected by the transmission map data selection unit. It is characterized by having.

The map data transmitting device is a map data transmitting device for transmitting map data to a moving map data receiving device which is a moving object, and the transmission map data selecting section includes a current position of the moving map data receiving device, The map data to be transmitted to the moving map data receiving device is selected based on a moving speed of the moving map data receiving device.

[0088] The transmission map data selecting section may dynamically change the timing of selecting the map data to be transmitted to the map data receiving device based on the data amount of the map data to be transmitted to the map data receiving device. Features.

[0089]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 In this embodiment,
The present invention relates to a map data selection unit that selects map data to be transmitted to a mobile terminal according to movement of a mobile terminal (for example, a mobile terminal or a map information receiving terminal using a mobile phone) that is a mobile map data receiving device. Further, the time at which the selected map data is displayed on the display screen of the mobile terminal is predicted (this time is referred to as a scheduled display time or a scheduled display time), and a map data transmission schedule is set based on the scheduled display time. The present invention relates to a transmission schedule setting unit for transmission. That is,
The invention according to the present embodiment predicts the time at which each part constituting the map data is displayed on the screen based on the moving speed of a mobile terminal (hereinafter, also referred to as a user or a client) and transmits the data in consideration of the scheduled display time. This is for setting a schedule.

FIG. 1 is a functional block diagram of a map data transmitting apparatus (hereinafter, also referred to as a server) according to the first embodiment. As shown in FIG. 1, 1 is a map data transmitting device according to the present invention, 2 is a map database unit,
A parts storage unit 3 for storing map parts (hereinafter, also referred to as "graphic parts" or simply "parts") constituting map data, and road traffic information / accidents having information on traffic congestion, traffic accidents, road construction, and the like. Construction information section 4 and POI
And a POI information section 5 having (Point of Interest) information. Reference numeral 6 denotes a user information database unit, which is used for the performance of the mobile terminal used by the user (memory size for storing map information, CPU performance, screen display size, etc.), the current position of the mobile terminal, the moving speed of the mobile terminal, and transmission. It has information on communication performance such as communication speed and communication band of communication media. Reference numeral 7 denotes a transmission target area selection unit, which is a transmission map data selection unit, and selects map data to be transmitted next from the current position and moving speed of the user (mobile terminal). Reference numeral 8 denotes a congestion status detection unit that detects a congestion status of a communication path between the map data transmitting device and the mobile terminal. Reference numeral 9 denotes a moving speed detecting unit which detects the moving speed of the mobile terminal. Reference numeral 10 denotes a division criterion setting unit, which sets a criterion for determining the priority of the first type data and the second type data to be described later. 11 is a priority setting unit that determines the priority of the transmission order of parts or the priority of transmission reliability or the priority that the user wants to see and display.
Static priority setting unit 1101 and dynamic priority setting unit 1102
Consists of Reference numeral 12 denotes a time detecting unit that detects a display scheduled time, a transmission processing completion deadline, a display end time, and a transmission end time, which will be described later. Each time will be described in detail later. 13
A transmission schedule setting unit sets transmission schedules such as selection / discarding of parts to be transmitted, transmission order for each part, and transmission timing. A packet generation unit 14 generates a data delivery packet (hereinafter, also simply referred to as a “packet”) storing parts. Reference numeral 15 denotes a packet transmission unit which transmits the packet generated by the packet generation unit according to the schedule set by the transmission schedule setting unit.

First, the function of the map database will be described. As described above, the map database unit 2 divides the map data into parts constituting the map data and stores the map data. Here, a part indicates a figure that indicates each road and each facility that constitutes the map data. For example, in the map data shown in FIG.
~ B3, etc., parking facilities B6 ~ B8, etc., building facilities B9, B10
Are called parts. In addition, the map database unit, for example, as shown in FIG. 2 (b), the parts constituting the map, expressways, toll roads, national roads, prefectural roads, general roads, local roads, traffic lights, name strings, parking lots, Building facilities, railways
It is stored separately for each group consisting of a monorail, a map symbol, and a background. Such classification is performed in advance by the static priority setting unit 1101, and a static priority is set for each group. A1, A2, B1, B
2, C1 and the like indicate parts constituting a map belonging to each group. Here, A such as national roads A6 and A7 indicates line information, and there are other roads (expressways and the like) and railway tracks. In addition, traffic lights B1 to B3, parking lots B6 to B8, etc.
Indicates point information, and there is another name character string (name information such as XX chome or XX park), and C of the backgrounds C1 and C2 indicates surface information, such as a display of a railway station. .

Each part is, as shown in FIG.
The type (line information) includes a priority (static priority), a supplementary point node list (coordinate information such as latitude and longitude indicating a road route), attribute information (road name, etc.), and a B type (point Information) includes priority (static priority), installation location (coordinate information such as latitude and longitude indicating the location of the building),
Attribute information (such as the name of a building), C type (surface information) include priority (static priority), installation area (coordinate information such as latitude and longitude indicating the location of the station), and attribute information (station information). Such as name).

Next, a procedure for selecting a transmission target area and setting a transmission schedule according to the present embodiment will be described with reference to the flowchart of FIG. In the present embodiment, basically, the transmission target area is selected (S301), the priority of the map parts is set (S302), and the scheduled display time is calculated (S301).
303), transmission schedule setting (S304), and transmission processing (S305). First, each step will be briefly described, and then will be described in detail. The transmission target area selection step (S301) is a step of selecting map data to be transmitted in response to a map distribution request received from a mobile terminal. When the display point is moved by scrolling, the area to be displayed is predicted in accordance with the scrolling, and the transmission target area is selected. When the route guidance is being performed and the user is moving, a transmission target area is selected by estimating an area to be displayed as the user moves. The step of setting the priority of the map parts (S302) sets a higher priority for the map parts that the user wants to see, that is, to display on the mobile terminal, by combining the above-described static and dynamic priorities. It is a step to do. The calculation step of the display scheduled time (S303)
This is a step of predicting a time at which map data is displayed on a display screen (display unit) of the mobile terminal. The transmission schedule setting step (S304) includes, in a predetermined time during which the user does not feel stress, the map parts in the transmission target area for which the priority has been set are preferentially distributed so as not to cause any trouble in using the map. This is a step of setting a distribution order by classifying the data into other data. In the transmission processing step (S305), map parts are transmitted at high speed using the RTP / UDP protocol according to the set transmission schedule, and retransmission is performed in consideration of real-time display of missing data at the session level in order to ensure reliability. This is the step of performing management. Note that this transmission processing step will be described in detail in Embodiment 8 described later.

Next, each step will be described in detail. First,
The selection of the transmission target area (S301), as described above, refers to selecting the next map area to be transmitted to the client from the map data held by the map database unit 2. The setting of the transmission target area is mainly performed by the transmission target area selection unit 7 which is a transmission map data selection unit. First, the meaning of the transmission target area will be described with reference to FIG. FIG. 4 shows map data held by the map database unit 2. A to G indicate each of the meshes, which are units in which the map database manages the map data. Further, x and y indicate the position of the mobile terminal. A range X indicated by a broken line is a display scope when the mobile terminal is at the position x (a range of a map displayed on the display screen of the mobile terminal), and a range Y is display when the mobile terminal is at the position y. Scope. In FIG. 4, the display scope is set so that the position where the client exists is displayed at the center.

It is assumed that the route as shown in FIG. 4 is currently set and the mobile terminal is at the position x. In this case, the display scope X spans the meshes A, B, C, and D. At this point, A within the display scope,
Since the map of the area spanning B, C, and D should be displayed on the display screen, the map data of meshes A, B, C, and D should have already been transmitted from the map transmission server to the mobile terminal. . Next, when the mobile terminal moves to the position of y, the display scope Y matches the mesh C. When the mobile terminal moves beyond the position of y and proceeds along the route, the display scope changes to the meshes E and F. , G. That is, the transmission target area when the mobile terminal exceeds the y position is an area that is next within the range of the display scope, in other words, meshes E, F, and G that are areas displayed on the display screen of the mobile terminal. Become. If the mobile terminal has sufficient memory capacity, before the mobile terminal reaches the position of y,
The map data transmitting device transmits the map data of the meshes E, F, and G to the mobile terminal. In addition, in the case where the transmitted map data is displayed in real time because the memory capacity of the mobile terminal is not sufficient, the map transmitting apparatus starts displaying the map data as the mobile terminal moves when the mobile terminal reaches the position y. It is necessary to sequentially transmit the map data of the meshes E, F, and G according to the portion that reaches the scope.
Thus, the meshes E, F, and G required when the mobile terminal reaches the position of y are transmission target areas.

The transmission target area is determined by the transmission target area selection unit 7 to 1) at the time of route guidance, the current position information of the mobile terminal, the route information, the moving speed of the mobile terminal (the maximum speed limit of the road on which the vehicle is currently traveling). 2) When the route is not guided, the current location information, the moving speed of the mobile terminal (including the maximum speed limit of the currently running road), and the traffic congestion. It is selected using information and the size of the display scope. The current location information, route information, moving speed, and the like of these mobile terminals are stored in the user information database unit 6, and the transmission target area selection unit 7 obtains the information from the user information database unit 6, and The transmission target area is selected according to the procedure described with reference to FIG.

Next, when the process of selecting the transmission target area is completed, the priority setting unit 11 sets the priority of the map parts constituting the transmission target area (S302). Depending on the degree of influence of each part on the map data, the required real-time properties of each part are different, and parts that should be transmitted early and parts that do not interfere even if transmission time is late are mixed in the map data I do. For this reason, a high priority is assigned to parts to be transmitted early by setting the priority, and parts having no problem even if the transmission timing is late are distinguished.
As will be described later, in the present invention, a packet storing each part is transmitted in principle without establishing a connection between the map data transmitting apparatus and the mobile terminal. For this reason, when a discard due to a packet loss or a bit error occurs, a packet that guarantees retransmission is distinguished from a packet that does not guarantee retransmission. The priority set for each part at the time of retransmission guarantee / non-guaranteed packet classification is used. This priority setting is performed using, for example, a route visibility-based priority setting table shown in FIG.

The priority setting table for each route visibility is a table in which a high priority is set to a guide route and a road or a facility which is high enough to enhance the visibility of the guide route. In other words, it indicates the display priority criteria such as thinning out low-priority parts when creating a deformed map, or which display has priority when facilities and roads are displayed overlapping, This is a priority setting criterion for displaying an easy-to-use map.

For example, it is assumed that a route visibility setting priority setting table shown in FIG. 5A is selected when there is a request for transmitting map data for which route setting shown in FIG. 6 has been made. In this case, the dynamic priority setting unit 1102 assigns each part included in the map data in FIG. 6 to a corresponding group among the groups illustrated in FIG. FIG. 7 shows FIG.
The result of allocating each part to each group is shown. That is, national road A6, national road A7, national road A8, prefectural road A1
6. Prefectural road A19, prefectural road A20, and prefectural road A21 correspond to the roads constituting the route (1) in the priority setting table, and these parts have the highest priority. That is,
In the static priority setting table of FIG. 2B, prefectural roads A16 to A21, which were not so high in priority, have the highest priority in FIG. Also, as a priority setting table, a part closer to the current position of the mobile terminal sets a higher priority. A priority setting table according to the current position distance or a part closer to the guide route has a higher priority. There is a guide route distance-based priority setting table to be set (both shown in FIG. 8). As described above, when the priority is set for each part, the transmission order is determined for each part so that the part having the higher priority is transmitted first. FIG. 9A schematically illustrates a state in which parts are arranged in an order of higher priority. Each of the arranged cells in the drawing represents a part, and A, B, C, and D displayed in the part indicate the set priority. The higher the priority, the higher the transmission order.

When the priority setting process is completed, next, the time detecting section 12 calculates the scheduled display time of each map part (S303). The scheduled display time means the time when the map starts to be displayed on the display screen of the mobile terminal. Hereinafter, a method of calculating the scheduled display time of each part by the time detection unit 12 will be described. First, a method of calculating a scheduled display time when each part is displayed on the screen by moving the mobile terminal will be described with reference to FIG. FIG. 10 shows the progress of the mobile terminal moving on the route and the range displayed on the display screen of the mobile terminal as the mobile terminal moves. X and y in FIG. 10 indicate the position of the mobile terminal. A range X indicated by a broken line is a display scope when the mobile terminal is at the position x, and a range Y is a display scope when the mobile terminal is at the position y. S is a part indicating a building. At present, it is assumed that the mobile terminal exists at the point x and is moving toward the point y. It is also assumed that the parts S start to be displayed on the display scope Y when the mobile terminal reaches the point y. Therefore, the time when the mobile terminal reaches the point y is determined by the part S
Is the scheduled display time TS. Assuming that the current time at which the mobile terminal is at the point x is T, if the travel distance d from the point x to the point y and the average moving speed V are known, the time to reach the point y can be calculated. That is, the scheduled display time TS of the part S is expressed as follows. TS = T + d ÷ V As described above, since the route is composed of a plurality of road parts, if the road part including the point x is the 0th part and the part including the point y is the nth part, the point x Is the sum of the distances between the end points of each part (0th part to (n-1) th part) and n
It is determined by the total distance from the end point of the th part to the y point. The distance between both end points of each road part is registered in the map database as attribute information of road data. When it is desired to increase the calculation processing speed of the scheduled display time, the distance between the two points x and y may be used instead of the travel distance d. As the average moving speed V, it is desirable to use the average moving speed from the point x to the point y when actually moving, but the moving speed must be predicted before actually moving. Therefore, for example, the average traveling speed V is calculated on the assumption that the vehicle travels at the maximum speed limit of the route. When there is a traffic jam, the average moving speed V is corrected by multiplying the average moving speed V by a coefficient indicating the traffic jam situation.

Next, a method of calculating a scheduled display time of a part when the display screen is moved by scrolling a pointer or the like will be described with reference to FIG. X in the figure is a display scope indicating an area displayed on the display screen of the mobile terminal, and Y is a display scope moved in the direction of the arrow. The point x is the center point of the display scope X, and the point y is the center point of the display scope Y. A method of calculating the scheduled display time of the part S when the center point of the display scope is to be scrolled from the point x to the point y by the scroll operation will be described. When the display scope X is at the position shown in FIG. 11, the scheduled display time TS of the part S is the time when the display scope is scrolled to reach the position of the display scope Y. That is, the time when the display scope moves and one side of the display scope reaches a position where the display scope contacts the part S is the display scheduled time TS of the part S. The moving distance when one side of the display scope moves to the position where it touches the part S, that is, the distance that the display scope moves from the position of X to the position of Y is equal to the distance between the two points x and y. Assuming that the distance is d, the scroll movement speed is v, and the time when the center point of the display scope is at the position of x is T, the scheduled display time TS of the part S can be expressed by the following equation. . TS = T + d ÷ v

Here, it should be noted that, in the case of moving the display screen by scrolling, unlike the case of moving the mobile terminal, the scheduled display time of the parts after the scroll is started is clarified. That is, in the case of scroll movement, unless the movement is started, it is not possible to start the calculation work of the scheduled display time. This is because the scroll direction and the scroll speed cannot be predicted in advance. For this reason, since the display scheduled time can be calculated only after the scroll is started, there is a difficulty that the display scheduled time must be calculated in a short time. Another point to be noted is that when the direction and speed of scroll movement change, the scheduled display time is also recalculated. However, when the scroll operation is performed manually, the scroll speed and the direction are not always constant, and it may be considered that there is some deviation. Therefore, even if the scroll direction slightly shifts, it is necessary to consider that the scroll direction does not change in calculating the display scheduled time. The same applies to the scroll speed, and slight changes in the speed are not considered. That is, only when there is a speed change equal to or more than a certain value, the speed change is reflected in the calculation of the scheduled display time.

Although the above description has been given of the case where the scheduled display time is calculated for each part, the calculation may be performed for each part or for each group (division data) obtained by dividing the transmission target area into a plurality. is there. Parts and divided data are collectively called partial data.

FIG. 9B schematically shows a state in which the scheduled display time TS is set for each part arranged according to the order of priority. Note that T1, T2, and the like in the drawing represent the scheduled display time TS, and the smaller the number, the earlier the scheduled display time (that is, T1 is earlier than T2).

After the display time is calculated for each part by the time detecting unit 12, the transmission schedule setting unit sets the transmission schedule based on the priority and the display scheduled time (S304). In the present invention, the fourth embodiment
As described in detail, each part is transmitted in a connectionless communication form that does not perform error control etc., guaranteeing retransmission when data loss or error occurs only for certain parts, other data is In principle, a retransmission is not always guaranteed. Therefore, a case will be described in which the transmission schedule by the transmission schedule setting unit is divided into data for which retransmission processing is always performed and data for which retransmission processing is not necessarily performed. The transmission schedule setting unit sets parts having a certain priority or higher as first type data and parts having a certain priority or lower priority as second type data,
The map parts ranked according to the priority shown in FIG. 9A are divided into two groups. The first type data is treated as retransmission guarantee data, and when a packet containing a graphic part is not normally received by a discard due to packet loss or bit error, etc., a retransmission guarantee packet that always retransmits the packet. Sent as The second type data is treated as retransmission non-guaranteed data. If a packet is not received normally, retransmission is attempted, but retransmission is not always guaranteed due to communication conditions such as congestion (best effort packet). Sent as FIG. 9C schematically shows a state in which the parts are divided into the first type data and the second type data based on a certain priority. In FIG. One type of data, priority C or lower is defined as second type data. Here, the criterion for distinguishing the first type data from the second type data is the priority, and the division setting unit 10 determines which priority level is used to divide the data. The setting of the sorting criterion by the sorting criterion setting unit is performed on the premise that transmission can be performed at a communication speed possessed as a communication function in a state where a wireless / wired communication line or network is not congested. For this reason, when the communication line becomes congested and the effective communication speed is reduced, it is necessary to change the priority level which is a reference for distinguishing the first type data from the second type data. The classification criterion setting unit also changes the priority, that is, adjusts the ratio between the first type data and the second type data.
Will be described in detail. After discriminating between the type 1 data and the type 2 data, the transmission schedule setting unit transmits the transmission order of the type 1 data that is currently ranked in the order of higher priority, the earlier the display scheduled time TS, the earlier the part. (See FIG. 34). On the other hand, the second type data remains in the transmission order in the order of priority (see FIG. 34). FIG. 9D is a schematic diagram illustrating a state in which the parts of the first type data that are initially arranged according to the priority are rearranged according to the scheduled display time. FIG. 9D shows a state in which the data of the display scheduled time T1 with the priority B is the priority A and the transmission order is earlier than the data of the display scheduled time T2.

The reason why the transmission order (transmission schedule) of the first type data is determined according to the scheduled display time will be described. The basis of transmission is to transmit a part with a higher priority first. However, when the amount of transmission data is large or when the available communication speed of the communication medium is low, it takes time to transmit the map data. For this reason, if the transmission according to only the priority is performed, the route information is transmitted from route information that is considerably far from the current location of the user at the time of route guidance, and necessary information near the current location of the user is not transmitted. Things can happen. Specifically, information about the next intersection is transmitted and
Since it is not displayed, the user may not be able to change the course and may not be able to proceed along the route. Since such a situation hinders route guidance, it is necessary to avoid such a situation as much as possible. The priority is set based on the type or property of the part as shown in FIG. 2B or FIG. 5A, and the part with the earlier scheduled display time is not always given priority. For this reason, there is a possibility that a part may be transmitted after the scheduled display time has elapsed since the transmission processing of the route with the higher priority is given priority. Therefore, the transmission order is determined according to the scheduled display time as well as the priority. By determining the transmission order in this way, transmission can be performed in consideration of the time required for display for each part.

When the transmission schedule is set by the transmission schedule setting unit 13 in this way, a packet is generated by the packet generation unit, and the packet transmission unit transmits the packet according to the set transmission schedule (S305).

In the present embodiment, the first type data is the retransmission guarantee type data and the second type data is the non-retransmission guarantee type data. However, all the data may not be retransmitted. Further, all data may be retransmitted. Even in this case, similarly to the above, it is possible to distinguish high-priority data from type 1 data and low-priority data from type 2 data, and rearrange the transmission order of type 1 data according to the scheduled display time. Deemed useful.

Further, the transmission schedule is set (S30
After 4), when the user requests to change the transmission target area or sets a new transmission target area (S
In 306), a changed or new transmission target area is selected (S301). Further, even if there is no need to change the transmission target area or make a new setting, the transmission schedule setting unit 13
Sets the transmission schedule, and after the packet transmission unit 15 starts packet transmission, when the moving speed detecting unit 9 detects that the moving speed of the mobile terminal has increased, that is, because the moving speed of the mobile terminal has increased. When the scheduled display time of each part is advanced, the once set transmission schedule may not be sufficient (S307). Similarly, after the transmission schedule setting unit 13 sets the transmission schedule and the packet transmission unit 15 starts packet transmission, when the congestion status detection unit 8 detects that the congestion status of the communication path has deteriorated, Because the communication speed has become slow, the transmission schedule once set may not be sufficient (S307). In this case, the transmission target area selection unit and the transmission schedule setting unit calculate the transmission target area and the scheduled display time of each part based on the new moving speed or communication speed, and set a new transmission schedule (S301 to S304). ). If the packet transmission unit is in the middle of performing the transmission process based on the previous transmission schedule, an instruction is also created as to when to switch from the previous transmission schedule being executed to the newly set transmission schedule. The transmission schedule setting unit does not set a schedule to start transmission from the part at the head of the newly set transmission permutation, but sets a schedule to start transmission from the part most effective for the user's route guidance. A specific switching method will be described with reference to FIG. FIG. 40 (a) shows map data, and for the sake of simplicity of description, only the guide route exists in the map data, and the guide route is divided for each of the following areas: In the map data, it is assumed that the guidance route includes nine road parts. Also, the mobile terminal shall move from the left side of the figure to the right side,
x indicates the current position of the mobile terminal. FIG. 40 (b)
Is a transmission schedule initially set, and the parts are arranged in the transmission order. FIG. 40 (c)
Is a transmission schedule newly set in accordance with a change in the moving speed of the mobile terminal. In the transmission schedule shown in FIG. 40 (c), the transmission order itself is the same as in (b), but the transmission must be started from an earlier time. Here, it is assumed that the time when the new transmission schedule (c) is set is when the mobile terminal is at the position x. At this time, the packet generation unit and the packet transmission unit perform the original transmission schedule (b).
And the transmission process of the parts is being performed. On the other hand, since the mobile terminal is already approaching the part, even if the data before the part is transmitted, it is meaningless for route guidance, and the map data transmitting apparatus needs to transmit the data immediately. Therefore, the transmission schedule setting unit instructs to stop the transmission processing of the parts based on the original schedule (b) and start the transmission processing of the parts based on the new schedule (c). As described above, the transmission schedule setting unit sets the switching timing based on the current position of the mobile terminal, and instructs the packet generation unit and the packet transmission unit. Note that the current position of the mobile terminal can be obtained from the user information database unit 6, and coordinate information such as longitude and latitude for each part is clear for each part as shown in FIG. Then, the packet generation unit and the packet transmission unit generate and transmit a packet according to the newly set transmission schedule according to the switching instruction from the transmission schedule setting unit.

Embodiment 2 FIG. 36 shows a state in which the transmission schedule adjustment unit 19 is provided in the main function of the map data transmission device 1 described in the first embodiment, and the transmission schedule adjustment request unit 32 is further provided in the mobile terminal 30. Here, the transmission schedule adjustment request unit 3 of the mobile terminal
The mobile terminal 2 has a function of requesting the server to adjust the transmission schedule of the map information by transmitting the current moving speed, the current position, the scheduled stop time at the parking area, and the like (moving status) to the server. Further, the transmission schedule adjustment unit of the server has a function of resetting the transmission schedule of the map information to the mobile terminal based on the movement status received from the mobile terminal.

Next, the transmission schedule adjustment unit 1 of the server when the transmission schedule adjustment request unit 32 of the mobile terminal 30 requests the server to adjust the transmission schedule.
The operation by which 9 adjusts the transmission schedule will be described. The transmission schedule adjustment request unit of the mobile terminal stops the car when the moving speed of the mobile terminal suddenly slows down, or when the moving speed suddenly changes, such as when the moving speed suddenly increases, or in an unplanned parking area. In this case, the server requests the server to change the map transmission schedule. For example, in the traffic jam information held by the server, it may be determined that the road is vacant, but in fact, there may be a discrepancy between the traffic information and the actual situation, such as a large traffic jam on the road. . in this case,
Since the transmission schedule is set based on the traveling speed that is faster than the actual traveling speed, if the transmission schedule is kept according to the transmission schedule, the map data is continuously transmitted even though the moving object itself hardly moves. Transmission occurs. Further, the moving speed is suddenly changed, and the moving at the changed speed may be continued. In this case, if the server sends map data in accordance with the transmission schedule calculated at a slow moving speed, even if the moving speed suddenly increases, the map required for display is obtained at the necessary timing. Would be difficult to do. Therefore, in order to avoid these problems, the transmission schedule adjustment request unit of the mobile terminal sends a message requesting that the transmission schedule be changed or adjusted because the movement at the changed speed is expected to continue for a while. Make a call to the server. The movement status information receiving unit (not shown) receives the message from the mobile terminal, and the transmission schedule adjusting unit resets the transmission schedule based on the current moving speed. The method of resetting the transmission schedule is the same as in the first embodiment. That is, the display scheduled time of each part is recalculated from the current (changed) moving speed, and the retransmission time limit time and the display end time are recalculated based on the new display scheduled time. Then, the first type and the second type of transmission rate and retransmission control are performed. Also, because the area size displayed per unit time changes, if the speed suddenly decreases, the map area displayed per unit time becomes smaller, so that detailed map information can be transmitted. Become. That is, parts with lower priorities can be transmitted. Conversely, when the moving speed suddenly increases, the size of the display area displayed per unit time increases. Therefore, it is difficult to transmit necessary data at a timing required for display if parts having the previously transmitted detail are transmitted. Therefore, in order to solve such a problem, the priority of parts to be transmitted is limited to a high priority, and the transmission schedule is reviewed so as to transmit map data of a wider area. When the transmission schedule is changed on the way, the transmission schedule is changed from a point at which a request for changing the transmission schedule is received and a point which has advanced a certain distance.
The transmission of the map parts to that point is performed according to the transmission schedule so far. Further, for example, when the vehicle is stopped in a parking area or the like, the vehicle does not move for a while, and the communication line is temporarily interrupted. In this case, it is specified to the server that the communication line was not disconnected due to the trouble of the communication device and the communication condition while moving. As a result, useless calculation in the server can be avoided, and the processing efficiency of the server can be improved. Upon receiving a message to park in the parking area from the mobile terminal, the server immediately suspends the map information transmission process and waits for a map transmission request. When the transmission request is received, the display scheduled time of the previously prepared map parts is recalculated and the transmission schedule is reset unless the destination destination is changed.
The calculation of the scheduled display time is performed by reflecting the current moving speed and the traffic congestion information.

In the present embodiment, since the above-described processing is performed, the server can calculate the display scheduled time with higher accuracy from the movement status information received from the mobile terminal. Then, it is possible to reset the transmission schedule, that is, adjust the transmission schedule based on the calculated estimated display time by using the method described in the above embodiment.
Unless it is based on the map data transmitting apparatus and the mobile terminal according to the present embodiment, the mobile terminal does not receive the movement status information, and therefore, the map data transmitting apparatus calculates the estimated display time according to a prepared criterion. Will be. For this reason, when a sudden traffic situation such as a traffic jam or an accident occurs, it is difficult to calculate in consideration of these circumstances. In the present embodiment, since such a sudden traffic situation can be obtained from the mobile terminal side, the accuracy of the display scheduled time of the map parts can be further improved. On the mobile terminal side, when the degree of arrival of the map-related information transmitted from the server is felt to be slow, for example, the map displayed on the display screen is always displayed only partially or in spite of being the first type of data. If the display timing is too late and the use of the map is hindered, the mobile terminal should request the transmission schedule to be adjusted (tuned) so as to increase the accuracy of the timing of transmitting the map information. For the purpose, the movement status of the mobile terminal is transmitted to the server.

Embodiment 3 In the present embodiment, after the time detection unit 12 calculates the scheduled display time for each part, the transmission processing completion deadline and the scheduled transmission processing completion time are calculated for each part, and the transmission schedule setting unit 13 calculates the respective calculation results. A case where the transmission schedule is set by comparison will be described. Here, the transmission processing completion deadline is a time limit indicating when transmission must be completed in order for each part to arrive at the mobile terminal by the scheduled display time, and the transmission processing completion time is , A scheduled time indicating when the transmission processing of each part is actually completed. In addition,
Both will be described in detail later.

The present embodiment will be described with reference to the flowcharts of FIGS. S1201 to S120
The processing up to 3 is the same as that of the first embodiment. The transmission target area selection unit 7 selects the transmission target area, the priority setting unit 11 sets the priority, and the time detection unit 12 detects the scheduled display time. FIG. 14A schematically shows a state in which the parts are arranged in the order of priority, and FIG. 14B shows a state in which the scheduled display time TS is set in each part arranged in the order of the priority. Is schematically represented. Next, in the transmission schedule setting (S1204), S12041 shown in FIG.
To S12047. First, in S12041,
As in the first embodiment, each part is classified into first type data that is handled as retransmission guarantee data and second type data that is handled as retransmission non-guaranteed data. Further, in S12042, the time detection unit 12 calculates the transmission processing completion deadline for each part based on the detected display scheduled time. In order to perform the map distribution service smoothly, it is necessary that each part arrives at the mobile terminal by the scheduled display time calculated for each part. On the other hand, transmission from the map data transmission device to the mobile terminal requires a certain transmission time (transmission required time). Therefore, the time calculated by subtracting the required transmission time from the scheduled display time of each part is the transmission processing completion deadline. In order for the part to arrive at the mobile terminal by the display scheduled time, the transmission processing completion deadline is required. By the time the transmission process must be completed. Note that, in principle, the transmission processing completion deadline is calculated for each part in the same manner as the display scheduled time, but may be performed for each group (division data) obtained by dividing the transmission target area into a plurality. Parts and divided data are collectively called partial data.

Next, a specific method of calculating the transmission processing completion deadline will be described. There are two types of transmission processing completion deadlines: a transmission processing completion deadline when retransmission is not required and a transmission processing completion deadline when retransmission processing is performed. In the present invention, retransmission is guaranteed for the first type data, and retransmission is performed as much as possible for the second type data in principle. Therefore, in the present invention, the transmission processing completion deadline calculated by the time detection unit 12 is basically the transmission processing completion deadline during retransmission processing. The procedure of the retransmission processing will be described in detail in Embodiment 8. When retransmitting data, it is necessary to calculate a transmission processing completion deadline in anticipation of a time for retransmitting data that has been lost or has an error in a communication channel, in addition to a required transmission time. That is, in this case, the time for notifying the server that retransmission is necessary because a loss or an error has occurred on the mobile terminal side (retransmission notification time) and the data transmission time for retransmission (retransmission required time) are set. Must be taken into account. Therefore, in principle, the transmission processing completion deadline is expressed by the following equation. Transmission processing completion deadline = Scheduled display time−Transmission required time−Retransmission required time−Retransmission notification time First, a method of calculating the required transmission time will be described. The required transmission time is a value obtained by dividing the data amount of each part by the effective communication speed of the network and wireless network between the server and the mobile terminal. Next, the retransmission notification time is a time required for the mobile terminal to determine that data loss or an error has occurred (loss / error determination time) and a time required for transmitting a retransmission request (retransmission request transmission time). Consists of The required retransmission time is represented as a value obtained by multiplying a required transmission time (data amount / effective transmission speed) by a loss / error rate which is a statistical probability of data loss or error. Therefore, the required retransmission time is represented by the following equation. Retransmission required time = transmission required time × (loss / error rate) Therefore, the transmission processing completion deadline is represented by the following equation. Transmission processing completion deadline = Scheduled display time-Required transmission time (data amount / Effective transmission speed)-Required retransmission time (Required transmission time x
(Loss / Error Rate) -Retransmission Notification Time The transmission processing time when retransmission is unnecessary is obtained by excluding the retransmission required time and the retransmission notification time from the above equation, and is therefore represented by the following equation. Transmission processing completion time limit = Scheduled display time-Transmission required time After the time detection unit calculates the transmission processing completion time limit for both retransmission processing and retransmission unnecessary time for each part, based on the priority and the transmission processing completion time limit, A transmission schedule setting section sets a transmission schedule. First, S120
At 43, the transmission order is rearranged to the order of the transmission processing completion deadline for the first type data (see FIG. 35). FIG. 14 (c)
Indicates a state in which parts are classified into type 1 data and type 2 data, and a transmission processing completion time limit tt is added to each part.
FIG. 14D shows a state where the first type data is rearranged in the order of the transmission processing completion deadline tt. Here, the first type data is rearranged in the order of the transmission processing completion deadline for the same reason as the first embodiment in which the first type data is rearranged in the order of the scheduled display time.

Next, the time detector 12 detects the transmission processing completion time, the display end time, and the transmission end time based on the display end time (S12044). Since the display end time and the transmission end time will be described later, they will not be described here. Here, the procedure for calculating the scheduled transmission processing completion time will be described. The scheduled transmission processing completion time is a scheduled time at which the transmission processing is completed for each part. The scheduled transmission processing completion time is the required transmission time and the required retransmission time of each part, and the packet generation processing time of each part (a value obtained by dividing the data amount of each part by the number of processing bits per unit time of the packet generation unit). Is calculated by accumulating. That is, if it is calculated in FIG. 14D that the transmission processing of the first part (priority A, transmission processing completion time limit t10) requires time t5, the transmission processing completion time of the data is estimated. Becomes t5. Then, when it is calculated that the time required for the transmission process of the second part (priority B, scheduled transmission process completion time t10) is t3, the scheduled transmission process completion time of the part is t5 + t3 = t8. . As described above, the time detection unit 12 accumulates and calculates the transmission processing time required for each part, and calculates the scheduled transmission processing completion time of each part. Then, the time detecting unit 12
Sets the transmission processing completion time for each part, and the transmission schedule setting unit 13 compares the transmission processing completion time with the transmission processing completion deadline for all parts of the first type data (S12045).

FIG. 15 shows the transmission processing completion time limit t for each part.
FIG. 5 schematically shows a state in which t and a scheduled transmission processing completion time tu are set. T10 described on the parts,
t20 and the like represent the transmission processing completion deadline tt, and t5 and t8 described below the parts are the transmission processing completion time t
u. Further, t5, t3, and the like described in parentheses below the scheduled transmission processing completion time tu indicate the time required for the transmission processing. In FIG. 15, the transmission processing of the first type data is scheduled to be completed for all parts by the transmission processing completion deadline tt.
The transmission is performed in the order of the transmission processing completion deadline tt (S1205). Although the transmission processing of the second type data is not to be completed by the transmission processing completion time limit tt, these second type data are parts having a lower priority than the first type data. Therefore, the transmission processing completion deadline tt
Even if the transmission processing is not completed by this time, the transmission is performed in the same transmission order, since there is no major obstacle to the map distribution service (S1205). On the other hand, FIG.
In this example, the scheduled transmission processing completion time tu of most parts other than some parts is later than the transmission processing completion deadline tt. That is, it is calculated that all the parts other than the first part (priority A, transmission processing completion time limit t10, transmission processing completion scheduled time t10) do not meet the transmission processing completion time limit tt. In this case, the transmission processing cannot be performed in time for the first-type data having a high priority, which greatly impairs the map distribution service. Therefore, data having a high priority must be transmitted as early as possible. In FIG. 16 (a), it is considered that the most serious problem is caused if the transmission of the fourth part and the sixth part to which the highest priority A is given cannot be made in time. And the transmission of the sixth part must be done in time. Therefore, the transmission order of the second part and the third part to which the priority B is assigned is turned backward, and the transmission order of the fourth part and the sixth part to which the priority A is added is changed. Move up (S12046). As a result,
The transmission processing of the fourth and sixth parts is completed until the transmission processing completion deadline tt (FIG. 16B). In FIG. 16A, the part of the fifth part (priority B, transmission processing completion time limit t20, scheduled transmission processing completion time t32) is also the second part to which the priority B is assigned. And the third part is turned backward, so that the transmission processing is scheduled to be completed by the transmission processing completion deadline tt, and the transmission order is advanced. In addition, there is no problem even if the advance is performed in this way, because the transmission of the parts having the priority A is in time.

Next, the display end time and the detection of the transmission end time based on the display end time performed by the time detection section 12 together with the detection of the scheduled transmission processing completion time (S12044) will be described. The display end time is the time at which a part that was in the display target area of the display scope moves out of the display target area of the display scope of the mobile terminal due to movement of the mobile terminal and disappears from the display screen of the mobile terminal (display of the display scope). (Time deviating from the target area). Therefore,
After the display end time has elapsed, it is meaningless even if the parts are transmitted, because they are not reflected on the display screen. The transmission end time is a time calculated by subtracting the required transmission time from the display end time, and the parts transmitted after the transmission end time has not been displayed on the display screen. For this reason, the transmission schedule setting unit 13 sets a schedule so as not to transmit a part whose transmission processing completion time is calculated to be later than the transmission end time.

Next, with reference to FIG.
The procedure for detecting the display end time according to will be described. FIG.
FIG. 5 shows a state in which the moving body is further moving from FIG. That is,
The moving body is moving from the position of y to the position of z. In this case, when the moving body moves to the position of z, the display scope moves to the position of Z. When the display scope reaches the position of Z, the display scope covers only the meshes F and G. That is, when the display scope moves to the position of Z, the mesh C completely disappears from the display screen. Therefore, the display end time of the rightmost part of the mesh C is when the moving body reaches the position of z. Of course, the parts on the center side or the left side of the mesh C disappear from the display screen before the moving body reaches the position of z, and the display end time comes earlier. The display end time is calculated for each part using the current position of the moving body, the moving speed of the moving body, and the size of the display scope. The current position information, the moving speed, and the like of these mobile terminals are stored in the user information database unit 6, and the time detection unit 12 obtains these information from the user information database unit 6, and ends the display by the above-described method. Calculate the time.

Next, the time detector 12 calculates the transmission end time based on the calculated display end time (S1204).
4). The transmission end time is a time obtained by subtracting the required transmission time from the display end time. The required transmission time is obtained in the same manner as described above. That is, it is a value obtained by dividing the data amount of each part by the effective communication speed of the network between the server and the mobile terminal and the wireless network. Then, the time obtained by subtracting the required transmission time from the display end time is the transmission end time.

FIG. 18A shows a state in which the transmission end time tv detected by the time detection unit 12 is given to each part. Since the transmission end time has already passed when the transmission processing is completed, the transmission schedule setting unit sets the transmission schedule setting unit to the transmission end time at the transmission processing completion time tu which is later than the transmission end time tv. It is determined not to transmit parts that are not in time (S12047), and those parts are discarded. As a result, the transmission schedule is as shown in FIG. 18B, the transmission order of the last part is advanced, and the transmission processing completion scheduled time tu is also t.
It hastened from 62 to t53. On the other hand, even when there is a part whose transmission processing is not to be completed by the transmission end time, if the map is to be reused, the part is transmitted even after the transmission end time elapses by estimating the time when the part is free. Will be. In other words, in the case of going back and forth between the same points, if there is sufficient memory capacity on the client side, data that could not be transmitted by the transmission processing completion deadline at the time of the route guidance on the outbound route is transmitted in the idle time, If the data is stored in the client, the data can be reused when the return route is guided.

In this way, the transmission schedule is set by the transmission schedule setting unit 13, then the packet is generated by the packet generation unit, and the packet transmission unit transmits the packet according to the set transmission schedule (S1205). Also, S1206 and S1207
The procedure of S306 and S306 of FIG.
307.

In the present embodiment, the first type data is the retransmission guarantee type data and the second type data is the non-retransmission guarantee type data. However, all the data may not be retransmitted. Even in this case, similarly to the above, high-priority data is distinguished from first-type data, and low-priority data is distinguished from second-type data. Is considered useful.

According to the invention of this embodiment, for example, when the moving speed of the user (mobile terminal) is slow, or when the map data is small, there is a large amount of time before display. It is possible to perform transmission processing of transmitting data during a vacant time until the transmission processing completion deadline.
Further, when the moving speed of the user (mobile terminal) is high or when there is a large amount of map data, it is physically difficult to transmit all the map data to be displayed by the transmission processing completion deadline. In the invention according to the present embodiment, even in such a situation, data having a certain priority or higher is transmitted with priority so that it is always displayed. Then, other map data that could not be transmitted even after the transmission processing completion deadline has elapsed is transmitted before the transmission end time. When the reuse of the map is taken into consideration, data that could not be transmitted by the transmission end time will be transmitted after estimating the available time. In other words, in the case of going back and forth between the same points, if there is sufficient memory capacity on the client side, data that could not be transmitted by the transmission processing completion deadline at the time of the route guidance on the outbound route is transmitted in the idle time, If the data is stored in the client, the data can be reused when the return route is guided.

Embodiment 4 In the present embodiment, a transmission schedule setting based on map prefetching which is an application of the map data transmitting apparatus described in Embodiment 3 will be described. The prefetch-based transmission schedule means that the user preliminarily prefetches map data having a large data amount when the data amount of the map data required next is small and the data amount of the map data required next is large. Every
This refers to setting a schedule in which transmission of map data having a large data amount is started in advance after transmission of map data having a small data amount is completed and before transmission is required. By doing so, the transmission of map data having a large data amount can be dispersed, and the transmission processing amount at the time of transmitting map data having a large data amount can be reduced. In the present embodiment, the map data is transmitted before the map data is displayed on the display screen of the mobile terminal, and it is assumed that the mobile terminal has a sufficient memory.

The transmission schedule setting based on prefetching will be specifically described with reference to FIG. FIG. 19 shows map data held by the map database unit 2, as in FIG. A to I indicate each of the meshes, which are units in which the map database manages the map data.
Further, x, y, and z indicate the positions of the mobile terminals. A range X indicated by a broken line is a display scope when the mobile terminal is at the position x, a range Y is a display scope when the mobile terminal is at the position y, and a range Z is when the mobile terminal is at the position z. Is the display scope of. In FIG. 19, the display scope is set so that the position where the client exists is always displayed at the center. Assuming that the mobile terminal is currently at the position x, the next transmission area to be transmitted is:
Meshes E, F, and G. These meshes E, F, and G
Is transmitted until the mobile terminal moves to the position y. On the other hand, the areas that need to be transmitted next to the meshes E, F, and G are the meshes H and I, and are transmitted in principle while the mobile terminal moves from the y position to the z position. That is, as a general rule, the mobile terminal moves from x to y
Until it moves to the position, it is allocated to the period of the transmission schedule setting and transmission processing of the map data of the meshes E, F and G. The schedule setting unit 13 sets the transmission schedules of the meshes H and I after the mobile terminal reaches the position of y. However, the data amount of the meshes E, F, and G is small,
While the transmission can be completed with a sufficient time margin before the mobile terminal reaches the position y, the data amount of the meshes H and I is large, and the transmission is performed while the mobile terminal moves from the position y to the position z. In some cases, it cannot be done. In this case, after the transmission of the meshes E, F, and G is completed, before the mobile terminal reaches the position y, a transmission area is selected in advance,
If the transmission of mesh H and I data can be started in advance, such a problem can be solved. A specific processing procedure of the map data transmitting device will be described. First, the transmission schedule setting unit 13 sets transmission schedules for the meshes E, F, and G. If the schedule is such that the transmission is completed with a sufficient margin before the mobile terminal reaches the position of y, the transmission target area selection unit 7 moves the meshes H and I forward to the next transmission target area. Select if there is. Then, the transmission schedule setting unit 13 sets a transmission schedule for the meshes H and I according to the procedure described in the third embodiment. The transmission schedule in this case is such that transmission starts before the mobile terminal reaches the position of y. When the data amount of the meshes H and I is large, the transmission schedule setting unit can also set the transmission schedule at which the transmission of the meshes H and I starts immediately after the transmission of the meshes E, F and G is completed. . That is, in the present embodiment, the transmission target area selecting unit dynamically advances the timing of selecting the transmission target area according to the data amount of the map data, and the transmission schedule setting unit transmits the transmission time according to the data amount of the map data. The schedule is dynamically advanced to set the transmission schedule ahead of schedule. With such a configuration, transmission of map data having a large data amount can be distributed,
It becomes possible to reduce the transmission processing amount when transmitting map data having a large data amount.

Embodiment 5 FIG. In the present embodiment, a display area priority transmission unit is provided in the map data transmission device. This display area priority transmission unit (not shown) temporarily interrupts the currently displayed map and displays a map of the designated area (a destination or a point distant from the point displayed so far). Or when displaying a point designated for the first time when the system is started, the map data (point information (POI) related to a map part or a map) that has become a display target area (within a display scope) of the display screen. )including)
, The transmission priority of the data related to the route, the data near the current location, and the data near the route is set high and transmitted to the mobile terminal. That is, when the user designates a point to be displayed and wants to be displayed, and attempts to display the designated point, the display area priority transmission unit selects a transmission target area of the map necessary for displaying the display screen. For the map data which is the display target area of the display screen, the transmission priority is set to the data related to the route, the data close to the current location, the data close to the route, and the like, and the data is transmitted to the mobile terminal. The method of setting the transmission schedule based on the scheduled display time is as described above. In the present embodiment, there is no scheduled display time and the display has already been performed (since the display has to be started at the time specified by the user instead of the display schedule). The method of setting the transmission schedule cannot be applied as it is. Therefore, when displaying a specified map, the map data in the display target area (within the display scope) of the display screen is transmitted prior to other map data. A transmission schedule is set for the data by applying the above-described transmission schedule setting method using the priority instead of the scheduled display time.

Next, the operation of the map data transmitting apparatus according to the present embodiment will be described. First, when a point desired by the user to be displayed is specified, a map to be displayed on the display scope is mapped with that point as the center of the display scope. The mesh of the map overlapping the display scope is the transmission target area. For example, as shown in FIG.
When the user specifies the point a and tries to display a map near the point a, the meshes A, B, C, and D are the transmission target areas. Among the selected transmission target areas, that is, meshes A, B, C, and D, map data that is already in the display scope is preferentially transmitted, and then map data outside the display scope is transmitted. Set the transmission schedule. First, for map data to be displayed in the display scope, priority is set so that the transmission priority of data related to the route, data near the current location, and data near the route is set high. The map data list in which the map data of the display target area (within the range of the display scope) for which the priority is set is transmitted based on the set priority is divided into the first type data and the second type data (FIG. 39). The first type data is a map part that is transmitted preferentially so that the minimum necessary map data that does not cause any trouble in using the map can be displayed within a predetermined time T (for example, within 3 seconds) when the user does not feel stress. It is. The second type data is a map part to be transmitted according to the priority after the transmission process of the first type data is completed.
The amount of data that can be distributed within a certain time T, which is the transmission time of the first type data, is determined based on the communication speed (transmission rate) of available communication media and the packet loss rate at the time of planning the transmission schedule. Is calculated. The selected data of the calculated transmittable data size in order from the top of the transmission priority order map parts list is the first data.
It becomes seed data. The packet loss rate is calculated from a moving average of the rate of occurrence of retransmission requests per unit time of data requested to be retransmitted, and in calculation, transmission data is calculated so that transmission processing of all data is completed within a fixed time T. . In Embodiment 1 described above, the scheduled display time of each map data is calculated and the transmission order is rearranged at the scheduled display time. However, in the present embodiment, the first type of data is already ,
Since they are displayed, the transmission order is determined according to the priority rather than the re-ordering based on the scheduled display time. This is because the first type of data has already been displayed, and displaying the map data to be displayed with priority is the map display that does not cause the user the most stress. Retransmission of the first type of data is guaranteed with priority even if the data is lost during transmission. The transmission order of the second type of data is set according to the priority in the same manner as in the first embodiment. Thereby, among the map data to be displayed on the display screen, the map data desired to be displayed by the user can be displayed with priority and without any loss, and the communication path may be congested. Even if the communication speed is degraded, at least the first type of data is guaranteed, so that there is an effect that no dissatisfaction or trouble occurs in using the map. In the present embodiment, the user does not move and does not move in the display target area. Therefore, there is no map data newly entering the display scope. Therefore, no matter how much the communication channel becomes congested, the map data necessary for all the displays will be transmitted someday. However, if there is a limit on displayable data due to memory storage restrictions or display screen size, data within the limit is transmitted. When the transmission processing of the map data of the display target area is completed, the transmission target areas (mesh A, B,
C and D) map data are transmitted. This is because the user may start moving or move the display target area by a scroll operation, so that the data is most likely to be required next for display. The map data existing outside the display scope in the transmission target area is map data that is not displayed unless the user moves or the user scrolls the display scope. Therefore, the map data of these areas are all transmitted as the second type of data. For this reason, in the present embodiment, the map parts are subjected to transmission processing in accordance with the transmission schedule in which the data having higher priority has a higher transmission order. If data is lost, retransmission is guaranteed as long as the user stays there. If the display scope starts to move once, the transmission process is interrupted even if there is untransmitted data in the transmission schedule. The processing shifts to processing for transmitting map data in the new transmission target area. However, in this case, only untransmitted data other than the transmitted data is transmitted. As described above, according to the present embodiment, it is possible to transmit the data of the transmission target area that is already displayed without causing the user to feel stress and without hindering the map use service. , Efficient map distribution becomes possible.

Embodiment 6 FIG. In the present embodiment, the adjustment of the ratio between the first type data and the second type data by the classification criterion setting unit 10 will be described. As described in the first or third embodiment, the transmission schedule setting unit 13 distinguishes the map data to be transmitted into the first type data and the second type data based on the priority. The criteria for discriminating between the type 1 data and the type 2 data are set by the sorting criteria setting unit 10. However, the setting of the sorting criteria by the sorting criteria setting unit is performed when wireless / wired communication lines and networks are congested. It is performed on the premise that transmission is possible at the communication speed provided as a communication function in a state where there is no communication function.
Here, when the communication line becomes congested and the effective communication speed is reduced, the actual required transmission time becomes longer than expected by the time detection unit 7. For this reason, if the classification of the first type data / second type data set without any congestion is maintained as it is and retransmission is guaranteed for all the first type data, the transmission and retransmission of the first type data It takes a long time to transmit the second type data. Also, when the communication line is congested, the probability of occurrence of packet loss or the like increases, and if retransmission is guaranteed for all of the type 1 data set in a situation where there is no congestion, the congestion calls for retransmission, and retransmission occurs. This leads to a vicious cycle of calling congestion. Therefore, the classification of the first type data / second type data once set should be dynamically changed according to the congestion situation. That is,
When the communication channel becomes congested, first, retransmission of the second type of data is stopped, and retransmission is unnecessary. If the transmission time is still desired to be reduced, the amount of the first type data to be distributed in the retransmission guaranteed packet is reduced, and the amount of the second type data to be distributed as the retransmission non-guaranteed packet is increased. It should be considered. Conversely, when the congestion has been alleviated, adjustment should be made such that the ratio of the once reduced first type data is increased and the ratio of the second type data is reduced. As described above, the division criterion setting unit 10 changes the priority, which is a division criterion once determined according to the congestion state of the communication line, and dynamically adjusts the ratio between the first type data and the second type data.

Next, a method of adjusting the ratio between the first type data and the second type data, which is performed by the division criterion setting unit, will be described. As described above, the first type data is distributed as a retransmission guarantee type packet, and the second type data is distributed as a retransmission non-guaranteed packet. Then, in principle, all data of both the first type data and the second type data must reach the mobile terminal by the scheduled display time detected by the time detection unit 7. For this reason, it is necessary for the division criterion setting unit to adjust the ratio between the first type data and the second type data so that transmission of all data (packets) is completed by the transmission processing completion deadline. The adjustment of the ratio between the first type data and the second type data is specifically performed by raising or lowering the priority of dividing the first type data and the second type data. For example, although data of priority C or higher was initially used as the first type data with reference to priority C, the standard is raised to priority B and only data of priority B or higher is used as first type data.
By doing so, the ratio of the type 1 data is reduced. In this case, the classification criterion setting unit increases the classification of the first type data and the second type data from the priority C to B to increase the data amount (packet amount) of the first type data (retransmission guarantee type packet). And the amount of increase in the data amount (packet amount) of the second type data (retransmission non-guaranteed packet). As a result of the calculation, when the classification criterion setting unit determines that all data can be transmitted by the transmission processing completion deadline, a new classification criterion is determined, and the new classification criterion (in this case, priority B) is set. Thus, the first type data and the second type data are separated. Also, priority C
As a result of calculating the amount of reduction of the type 1 data and the amount of increase of the type 2 data due to the change from "B" to "B", it may not be sufficient to simply change the sorting criterion to the priority B. That is, priority B
If all the transmission processes are not completed by the transmission process completion deadline even if it is changed to, the classification criterion is further raised to the priority A. In this way, the section criterion setting section dynamically changes the section criterion. Further, when changing the classification criteria described in the previous example from the priority C to the priority B, care should be taken. When there are many data (packets) having the priority C and many data of the priority C are converted into the second type data, the first type data becomes extremely small conversely. It is assumed that the transmission of all data is completed at a very early stage.
In this case, since the adjustment is excessively performed, the division criterion setting unit returns a part of the data of the priority C set as the second type data to the first type data again, and the first type data and the second type data. Adjust the seed data ratio to an appropriate level. When the congestion of the communication path is resolved, the amount of the first type data to be distributed in the retransmission guaranteed packet is increased and the amount of the second type data to be distributed in the retransmission non-guaranteed packet is reduced by a procedure reverse to the above. I do.

Embodiment 7 FIG. The present embodiment is intended to smooth the display on the mobile terminal even when a sudden change in network traffic occurs. When a sudden change in network traffic occurs, the total amount of data that can be transmitted changes rapidly. When the total amount of transmitted data changes, the degree of detail of the displayed map changes.
If the degree of detail of the map changes extremely, it is highly possible that the display will look strange. Therefore, in the present embodiment, the transmission schedule adjusting unit 19 shown in FIG. 36 determines the total amount of transmission data so that the detail of the display does not change abruptly and changes as smoothly as possible even when the traffic increases abruptly. To adjust. Hereinafter, the operation of the transmission schedule adjustment unit according to the present embodiment will be described. When the traffic becomes extremely large, if there is enough time in the transmission allowable time (the time until the scheduled display time of the data to be transmitted), the transmission rate is lowered but the total transmission data amount is not changed. If there is enough time before the scheduled data display time, the data is transmitted at a transmission data rate equal to or lower than the effective communication speed of the communication path. This means that by transmitting data so that traffic is kept as low as possible, even if the network becomes congested, it is possible to always transmit the required data amount when necessary, without reducing the total transmitted data amount as much as possible. This is because the communication path is always kept free. Therefore, if there is enough time in the scheduled display time, the time required for transmission slightly increases, but even if the transmission rate is lowered, the planned total transmission data amount can be maintained. The larger the room, the larger
Because the time that can be spent for transmission is extended,
As a result, transmission at a low transmission rate can be performed. The congestion status of the communication line is detected by the congestion status detection unit 8. As described above, since the transmission is performed with the transmission rate kept as low as possible, there is no effect if the traffic is slightly increased. When the traffic further increases and the current transmission rate cannot be maintained, the transmission rate is reset within a range where the total transmission data amount can be transmitted by the scheduled display time. In addition, if traffic increases and all transmitted data is transmitted at the currently available communication rate, but cannot be transmitted,
The total transmission data amount is reduced by the amount that cannot be transmitted. In this way, the transmission schedule adjustment unit adjusts the transmission rate and adjusts the transmission schedule so that data transmission processing can be performed at an optimal transmission rate so that the total transmission data amount does not decrease as much as possible even when traffic increases. Set again. That is, when the allowance for the allowable transmission time gradually disappears, the total transmission data amount is reduced according to the decrease in the allowance for the allowable transmission time. As described above, when there is a margin in the scheduled display time, this margin can be allocated to data transmission for smoothing a change in the detail level of the display. That is, as described above, the transmission schedule adjusting unit 1
No. 9 dynamically adjusts the transmission schedule according to the congestion state so that the transmission of the total transmission data amount can be maintained as much as possible even when network traffic and communication lines are congested.
Further, when the traffic sharply decreases, a map transmission process is performed so as to approach the requested display detail as soon as possible, rather than smoothly changing the display detail. Therefore, the transmission rate of the map is immediately increased to the transmission rate of the available communication media, and the total amount of transmitted data is immediately increased.

Embodiment 8 FIG. In the present embodiment,
Packet generator 14 of map data transmitting device according to the present invention
, And packet transmission by the packet transmission unit 15 will be described. As described above, the prior art 3
(Japanese Unexamined Patent Publication No. Hei 10-300499), TCP (T
transmission Control Proto
col) protocol. The connection-type TCP protocol is a best-effort data transmission that performs delivery confirmation, connection establishment, order control, error detection / recovery processing, and the like for each packet to be transmitted. For this reason, transmission of a large amount of data such as a map requires a long time for transmission processing, and transmission of map data having a high real-time property impairs a service. In the present embodiment, a description will be given of a real-time transmitting means which solves the problems of the conventional technology, can be used in a portable terminal or the like which requires a high degree of real-time property, and at the same time, ensures transmission reliability. In the present embodiment, map data is sent to a UDP (U.S.
real-time transmission based on the “Ser Datagram Protocol” protocol. In this case, since transmission confirmation, connection establishment, order control, error detection / recovery processing, and the like are not performed, TCP (Transmission)
This enables high-speed transmission as compared with the ION Control Protocol. On the other hand, there is a problem that the reliability of data transfer is inferior because delivery confirmation, order control, error recovery processing, and the like are not performed. To solve this problem, a sequence number is added to each packet, and delivery confirmation, order control, and error recovery processing are performed at the session level. For example, RTP (Real-ti
The present embodiment is realized by using a “Me Transport Protocol” packet. In addition, each part that is a component of the map has a different required real-time display depending on the purpose of use. Also, depending on the purpose of use, the degree to which the data is lost even when data is lost during the data transfer is different, and the allowable waiting time until the data is complemented is different. This is referred to herein as the media characteristic of the map. In the present embodiment, transmission Q in consideration of the media characteristics of this map
Transmission control for realizing oS is realized. in this way,
In the present embodiment, high-speed transmission by real-time transmission of map data and transmission QoS by retransmission control in consideration of real-time performance and reliability according to the purpose of use are realized.

As described in the first or third embodiment, after transmission schedule setting section 13 sets a transmission schedule, packet generation section 14 generates a packet storing parts to be transmitted. This packet generation unit generates a transmission content notification packet in addition to a data delivery packet which is a packet storing parts. The packet transmitting unit 15 transmits the transmission content notification packet and the data delivery packet without establishing a connection between the server and the mobile terminal. Here, the transmission content notification packet is a sequence number of a first type packet that is a retransmission guarantee packet that guarantees retransmission of a packet when discard occurs due to packet loss or bit error, etc.
A packet including a sequence number of a second type packet, a user / transmission request authentication identification information, etc. as a non-retransmission guarantee packet that does not guarantee retransmission, and a first type packet to a mobile terminal prior to transmission of a data delivery packet. , Second
Sent to notify the sequence number of each of the seed packets. That is, it is a sequence number notification packet. Also, the data delivery packet is a packet storing parts, a sequence number indicating a packet transmission order, a time stamp indicating a packet creation time or a transmission time, a data type of a part which is a component of a map to be packed in the packet, and , And data of map parts to be transmitted.

Next, the operation of the map data transmitting apparatus according to the present embodiment will be described using the flowchart of FIG. For example, it is assumed that the transmission schedule is set according to the procedure described in the first or third embodiment. That is,
It is assumed that the parts to be transmitted and the transmission order have been determined (S
2001). First, the packet generation unit 14 performs the first type packet that guarantees retransmission of the packet and the second type that does not guarantee retransmission according to the classification of the first type data and the second type data set by the transmission schedule setting unit 13. With two kinds of packets,
The parts to be transmitted are sorted (S2002). After the retransmission guarantee / non-guarantee of the part to be transmitted is determined, the total number of first type packets and the total number of second type packets required to transmit the map data to be transmitted are calculated. Since the number of bytes of the data area (data area size) required for storing the data in the packet according to the data type of the part is determined in advance, the packet can be easily packed if the data type of the part is known. The required data size is determined. In principle, one part is accommodated in one packet, but one part may be accommodated over a plurality of packets. If one part is divided into a plurality of packets, restoration reconstruction processing in the mobile terminal is important. The restoration reconstruction processing in this case will be described later.
Next, the packet generation unit assigns a sequence number to all calculated packets (S2003). In the present embodiment, since transmission is performed without establishing a connection, the mobile terminal determines whether a packet loss has occurred based on this sequence number and whether to make a retransmission request for the lost packet. (Whether or not the lost packet is a type 1 packet). Also,
Since the first type packet contains parts to be transmitted quickly or parts to be transmitted surely, in principle, the first type packet
A sequence number is assigned first from the seed packet. Thus, the sequence number assigned to the first type packet,
The sequence number assigned to the type 2 packet is determined,
A list of sequence numbers assigned to each is determined. Next, the packet generator 14 creates a transmission content notification packet (S2004). The transmission content notification packet has the configuration shown in FIG. 21 and includes a sequence number list of the first type packet, a sequence number list of the second type packet, and authentication identification information (for each user or for each transmission request from the user). User / transmission request authentication identification information). That is, the transmission content notification packet has a role of notifying the mobile terminal of the sequence number of the first type packet and the sequence number of the second type packet for a series of data delivery packets to be transmitted. The user / transmission request authentication identification information is a type of security code assigned to a series of packets to be transmitted. For example, the packet sent from the server should not be misused by other users or other applications, or even if the same user sends a packet for a different transmission request, the receiving side This is to prevent erroneous processing from being performed. It also has the role of reliably charging for services provided in response to user requests.

Next, the packet generator 14 creates a data delivery packet storing parts of the map data (S2005). Here, the packet generation unit 14 stores the parts with higher priority in the data delivery packet with priority. Also, in principle, one part data is stored in one packet. In the method of displaying after all the received packets have been received, display may not be possible even though there is map data being received, which may hinder map display and other processing. is there. Since the map data is disassembled and transmitted in parts, it cannot be displayed at all until all parts arrive, and can be displayed on a viewer or a browser for each received part. However, even if individual parts are not displayed, the data constituting the parts cannot be collected. Therefore, every time one packet is received, the part data is stored in one packet so that the part data stored in the received packet can be restored and reconstructed and displayed. In this way, by storing the parts in the packet, each time the parts are received, additional display can be sequentially performed. Also, the data of the parts to be packed in the data delivery packet may be the actual data of the parts as they are, only the data that changes among the actual data may be extracted, or the extracted data may be compressed. After receiving the data, the method of restoring the data of the parts packed in the data area of the parts after the reception can be specified by the data type of the parts contained in the data delivery packet. As described above, one part is stored in one packet in principle. However, one exception is that one or more parts can be stored in one packet. It is also possible to store one part over a plurality of packets. In this case,
In order for the mobile terminal to accurately restore the parts data stored over a plurality of packets, it is necessary to clearly indicate the association between the plurality of packets to the mobile terminal. Therefore, the packet generation unit 14 adds, to each of the plurality of packets, additional information including the total number of packets constituting the part data and the identifier of the part.
Then, when additional information is added to the received data transmission packet, the mobile terminal collects a plurality of packets having the same part identifier according to the additional information, sorts them in order of sequence number, and The restoration processing is performed in order from the small packet data.

As shown in FIG. 21, a data delivery packet in which parts are stored by the above-described procedure is packed with a sequence number indicating a transmission order for each packet, a time stamp indicating a packet creation time or a transmission time, and a packet. The data type of the part to be transmitted and the data of the part to be transmitted are constituent elements. When the packet generator completes the process of creating the transmission content notification packet and the data delivery packet in the above-described process, the packet transmitter of the server then keeps the connection (connection) between the server and the mobile terminal. First, a transmission content notification packet is transmitted to the mobile terminal that has issued the map information transmission request (S2006). Thereafter, when the mobile terminal successfully receives the transmission content notification packet, the mobile terminal confirms the normal reception confirmation information / message indicating that the transmission content notification packet has been normally received and the authentication received from the server or the transmission content notification packet. A reception acknowledgment signal or a return packet including a reply user / transmission request authentication identification information for the information is created and transmitted to the server. After transmitting the transmission content notification packet, the server is in a standby state until receiving the reception confirmation signal or the return packet from the mobile terminal. When the server receives the acknowledgment signal or the return packet, it confirms the reply user / transmission request authentication identification information, and after confirming that it is the correct transmission destination, the packet transmission unit of the server starts transmission of the data delivery packet. (S2007). The transmission of the data delivery packet is carried out mechanically and continuously without checking whether the transmitted data delivery packet has been normally received by the destination mobile terminal. The transmission content notification packet includes user / transmission request authentication identification information for identifying whether or not the other party may transfer the map information in response to a request from the mobile terminal. The server receives the reply user / transmission request authentication identification information created by performing a predetermined process using the transmission request authentication identification information, and obtains the result obtained by performing the predetermined process on the server. Check if you can send the map. If the packet transmission unit of the server determines that the transmission is permitted,
The transmission of the data delivery packet is started (S2007).

On the mobile terminal side, whether the received data delivery packet is the first type packet or the second type packet is determined by the sequence number notified by the previously received transmission content notification packet, and an error occurs. Or retransmission processing when a packet loss occurs. If no packet is received for a certain period of time after the packet is transmitted, it is determined that the packet has been lost. The certain time for determining the packet loss can be arbitrarily determined by the system. If the first type packet is not normally received due to an error or packet loss, the mobile terminal notifies the server of the sequence number of the unreceived packet and requests retransmission processing (S2008). Packet transmission unit 14
Retransmits the packet requested to be retransmitted (S200).
9) After the transmission of all the first type packets is completed, the second
The transmission of the seed packet is started (S2010).

Regarding the retransmission timing of the type 1 packet, since the type 1 packet usually contains the data to be transmitted quickly and reliably, the retransmission of the type 1 packet must be performed before the transmission of the type 2 packet. In principle, it should be terminated. In other words, the server receives the retransmission request from the mobile terminal while performing normal transmission of the type 1 packet, retransmits the packet requested to be retransmitted, and performs normal transmission of all type 1 packets and all retransmission requests. After the retransmission of the type 1 packet has been completed, the transmission of the type 2 packet is basically started. At this time, the server determines which should be given priority to the type 1 packet to be transmitted or the packet requested to be retransmitted. The priority of the packet to be transmitted and the packet to be retransmitted are determined. The priority is determined by comparing with the priority of. FIG. 22 shows a process of transmitting a packet between the server and the client and a process when a retransmission request is issued. A, B, and C displayed in each packet indicate the priority of transmission reliability. The priority of the transmission reliability is given to each packet by the priority setting unit 11, and the priority setting unit sets the priority according to the priority setting table shown in FIG. 2 or FIG. The method of setting the priority is the same as the setting of the priority of the transmission order described in the first embodiment. FIG. 22 illustrates a state in which, after packets are transmitted in the order of A, A, B, B, and C, the server receives a retransmission request for a previously transmitted packet (priority A) from the mobile terminal. Immediately before accepting this retransmission request, the server was preparing for transmission of a priority C packet. However, the priority of the packet that has received the retransmission request is A, which is higher than the priority C of the packet that is being prepared for transmission.
The distribution of the packets of the priority C is temporarily suspended, and the retransmission processing of the packets of the priority A is performed with priority. After the retransmission processing of the priority A packet is completed, the transmission processing of the temporarily interrupted packet of the priority C is started. In this way, the priority of the packet requested to be retransmitted is compared with the priority of the packet to be transmitted, and the transmission processing of the packet with the higher priority is performed with priority. By performing such QoS control for retransmission, parts with higher priority can be displayed more quickly. As another retransmission processing method, after the normal transmission of the first type packet is completed, the second
There is a method of collectively retransmitting the first type packets that have received the retransmission request before starting the transmission of the type packets. Further, after the transmission of all data delivery packets is completed (that is, after the transmission of the second type packet is completed), the first
It is also possible to perform retransmission of the seed packet collectively.

As described above, in the present embodiment, the server transmits a data delivery packet without establishing a communication connection with the mobile terminal. Therefore, since the process for establishing the connection is not required, the load of the transmission process is reduced. In an environment where communication is more likely to be interrupted than in a wired LAN, as in wireless communication, the transmission processing is further speeded up as compared with the case where a connection is established. Further, since the data delivery packet is transmitted without confirming the reception of the transmitted packet, a processing time and a waiting time for the confirmation processing are not required, so that the transmission processing is further speeded up. On the other hand, retransmission control can be performed for data that is to be reliably delivered to the mobile terminal by specifying the sequence number, so that the reliability of transmission is also ensured.

Embodiment 9 FIG. This embodiment is an embodiment in which the transmission content notification packet is changed to the configuration shown in FIG. In the eighth embodiment, the transmission content notification packet notifies the mobile terminal of both the sequence number of the first type packet and the sequence number of the second type packet. However, in the case of a type 2 packet, since retransmission processing is not guaranteed, it is considered that the mobile terminal does not necessarily need to know the sequence number of the type 2 packet. Therefore, in the present embodiment, the server notifies only the sequence number list of the type 1 packet, and when the transmission of the type 2 packet is completed (that is, when the transmission of all data delivery packets is completed), the server is notified that the transmission is completed. Is transmitted. Therefore, in the present embodiment, the mobile terminal recognizes only the sequence number list of the first type packet.

FIG. 24 shows another configuration of the transmission content notification packet. In order to determine whether a data delivery packet that has not been normally transmitted to the mobile terminal is a type 1 packet or a type 2 packet, it is necessary to notify only the first sequence number and the last sequence number of the type 1 packet. Conceivable. That is, if the data delivery packet that has not been received normally has a sequence number between the first sequence number and the last sequence number, the mobile terminal can determine that the packet is a type 1 packet, and If the packet has a sequence number after the number, it can be recognized as a second type packet. Therefore, the transmission content notification packet notifies only the sequence number of the data delivery packet at the beginning of transmission, that is, only the sequence number of the first type packet at the beginning of transmission, and transmits the first type packet after the transmission of the last type 1 packet ends. The first type packet final notification packet (retransmission guarantee packet transmission end notification packet) for notifying the sequence number of the final sequence is sent. Then, when transmission of all data delivery packets is completed, a transmission end notification packet (retransmission non-guaranteed packet transmission end notification packet) is transmitted. The specific mode of the first type packet final notification packet and the transmission end notification packet is as shown in FIG.

Embodiment 10 FIG. In the eighth embodiment, an example has been described in which all of the transmission content notification packet and the data delivery packet are transmitted without establishing a connection. In the present embodiment, the map data transmitting apparatus has a packet transmitting unit capable of selecting both connectionless transmission and connection transmission. For some packets, connection-oriented transmission is performed with emphasis on transmission reliability and reliability. Send. For example, when there is a time margin before a transmission time limit such as a scheduled display time, a transmission content notification packet which is a content to be surely delivered to the mobile terminal and a high-priority packet which is a first type packet in connectionless communication. Connection type TC for parts data
The transmission is performed based on the P protocol, and the part data as the second type packet is transmitted based on the connectionless UDP protocol. With such a configuration, it is possible to perform map transmission that flexibly achieves both reliability and real-time operation according to the transmission environment.

Embodiment 11 FIG. The invention according to the present embodiment is to select an appropriate communication line from a plurality of communication lines according to the real-time property required for the transmitted map data. This function is performed by a communication line / communication medium switching unit (not shown) which is a communication path setting switching unit. The communication line / communication medium switching unit dynamically switches the communication medium and communication line to be used based on the congestion situation of the communication medium according to the required degree of the real-time property of the map information contained in the packet to be transmitted. Control switching. In other words, out of the available communication media and communication lines notified from the mobile terminal, packets containing map information that requires a high degree of real-time performance use empty communication media, A packet containing map information and map-related information that is hardly required uses a relatively crowded communication medium. Hereinafter, an operation in which the communication line / communication medium switching unit dynamically controls switching between the communication media and the communication line will be described. The first type data is data having a higher real-time property than the second type data. Therefore, the first type data is distributed using a communication medium having a high effective communication speed, and the second type data is distributed using a low speed communication medium. Thus, it is determined whether the data is the first type or the second type of data, and the first type data is
A communication medium having a high effective communication speed is selected, and for the second type data, map data is distributed using a communication medium having a low communication speed. As a result, even when a plurality of users use the map data transmission device simultaneously in parallel, transmission of the first type data requiring real-time properties is all performed through the high-speed data communication path.
Therefore, even when used by a large number of users, there is an effect that the first type data having high real-time properties can always be delivered to each of the large number of users at a high speed.

Embodiment 12 FIG. In the present embodiment, the retransmission process is performed using the retransmission level indicating the frequency at which the packet transmission unit 15 retransmits the data delivery packet for the number of times the mobile terminal has not received the data delivery packet normally. . FIG. 37 is a diagram illustrating the map data transmitting apparatus 1 and the mobile terminal 30 according to the present embodiment. The retransmission level setting unit 18 sets a retransmission level, and the retransmission request transmission unit 32
Sends a retransmission request for a data delivery packet that has lost a packet. In addition, 1 which is assigned the same code
7 to 11 and 11 to 15 are the same as in the first embodiment. First, the retransmission level will be described. Whenever a packet loss or the like occurs, the need for retransmission occurs each time. However, the retransmission frequency and ratio indicate how many times the need for retransmission must occur for one retransmission process. Level. For example, if the content of the retransmission level is
It is assumed that one retransmission process is performed for the necessity of five retransmissions. In this case, when a packet loss occurs five times between packets of the same retransmission level and the necessity of five retransmissions occurs, the packet of the same retransmission level is retransmitted once. Then, the packet subjected to the fifth packet loss occurring between the packets at the same retransmission level, that is, the fifth packet lost at the same retransmission level, becomes the target of retransmission. That is, for data with a high retransmission level, retransmission processing is performed immediately if there is a packet loss, but for data with a low retransmission level,
Even if a large amount of packet loss occurs, it is difficult to perform retransmission processing.

The retransmission level is set in retransmission level setting section 18 arranged in map data transmitting apparatus 1 shown in FIG. The retransmission level setting unit 18 sets a retransmission level for each packet in accordance with the priority of the map data stored in the packet. That is, the retransmission level is set higher for packets including parts with higher priority, and the retransmission level is set lower for packets containing map data with lower priority. Specifically, a mode is conceivable in which the maximum value of the retransmission level is set to 1, and the levels are sequentially reduced to 2, 3, and 4. In this case, the maximum value of level 1 indicates that if there is a need for retransmission once between packets of the same retransmission level, retransmission processing is performed. Therefore, if level 1 is set, each packet is retransmitted whenever a packet loss or bit error occurs. Also, at level 2, when the need for retransmission occurs twice between packets of the same retransmission level, that is, retransmission processing is performed once for every two packet losses between packets of the same retransmission level. Then, set the lowest retransmission level to 0
The packet for which the retransmission level 0 is set is not retransmitted even if a packet loss or a bit error occurs. For example, there is a usage method in which a retransmission level is set only for the first type data, but it is also an effective method to provide the retransmission level for both the first type and the second type and perform retransmission control. next,
After the retransmission level is assigned to each packet by the retransmission level setting unit, each packet is transmitted from the packet transmission unit 15 to the mobile terminal. The mobile terminal 30 is provided with a retransmission request transmission unit 32, which analyzes the retransmission level set for each packet and issues a packet retransmission request to the server according to the number of times determined by the retransmission level. That is, the retransmission request transmission unit issues a retransmission request for a packet that has been lost at a probability that is set in advance according to the level of the retransmission level of the packet determined to be a packet loss. For example, if the retransmission request transmission unit 32 has determined that a packet in which the retransmission level 3 is described has been lost twice so far, when the next packet loss occurs in the level 3 packet, The retransmission request transmission unit transmits a retransmission request to the server. With this configuration, the necessity of retransmission has increased due to the congestion of the communication path. However, even when it is difficult to retransmit all packets, priority is given to retransmission of higher priority parts first. Is made.
For this reason, even when congestion is large, display according to the priority can be performed on the display screen of the mobile terminal.

Embodiment 13 FIG. Next, a description will be given of a discarding process realized by the map data transmitting apparatus and the relay station according to the present invention in consideration of packet priority. As described above, the conventional relay station performs the discarding process without affecting the attributes of the packet such as the importance of the transmitted packet. For this reason, more important data and data with high real-time property are discarded, and less important data and data with low real-time property are relayed. First, the packet generator 14 of the map data transmitting device
Stores the priority of transmission reliability set by the priority setting unit 11 for each part when storing the part in the data delivery packet. That is, a packet storing a part to which a high priority is set is given a high priority. The priority setting unit and the procedure for setting the priority are the same as those described in the first embodiment. The method of storing the priority in the data delivery packet is arbitrary. For example, the priority may be described in the header of the data delivery packet. When the data delivery packet generated in this way is transmitted, the relay station discards the packets with the lower priority given to the packets according to the necessity of discarding the packets. FIG. 26 shows a situation in which three packets to which three types of priorities A, B, and C are assigned are transmitted, and the relay station 20 relays these three packets. In this case, it is assumed that A has the highest priority and C has the lowest priority. FIG. 26 (a)
In, because the congestion state is small, the relay station 20 relays all packets. Next, as the congestion increases from FIG. 26 (b) to FIG. 26 (c), the necessity of packet discarding also increases. For this reason, FIG.
In FIG. 26, only C with low priority is discarded, and in FIG. 26C, only A with highest priority is relayed, and the rest are discarded. In either case, since packets with lower priority are discarded, A with the highest priority is relayed, and data that must reach the mobile terminal even if congestion increases is transmitted. become.

Even when a packet including a plurality of parts (composite data delivery packet) is transmitted as shown in FIG. 27, the priority can be set for each part and the priority can be described in the header of the packet. For example, a part storing a low-priority part is preferentially discarded in accordance with a congestion situation, so that a part assigned a high priority A can reach the mobile terminal without being discarded. In FIG. 27, unlike the case of FIG. 26 where the entire packet is discarded, the relay station cuts one packet for each part and partially discards it. Therefore, it is necessary for the relay station to accurately recognize the boundary between the part to be transferred and the part to be discarded. As this method, it is conceivable to describe in the header of the packet which part of the packet is to be cut. For example, as shown in FIG. 28 (a), a high-priority part is always stored at the head, and a low-priority part is always stored at the tail. It is described that the part A is stored, and that the nth and subsequent bytes have the priority B. Also, as shown in FIG. 28 (b), parts with low priority are always fixed bytes p from the end of the packet.
It is also possible to store the data after the byte, and the relay station can mechanically discard the data after the p-th byte from the tail without referring to the contents of the header. If the data amount of the low priority B parts is less than p bytes during packet generation, the packet generation unit inserts dummy data between the priority A parts and the priority B parts. It is necessary that parts with low priority are always stored after the p-th byte from the tail.

With such a configuration, even if the communication path becomes congested, highly important data is not discarded by the relay station, so that it can be reliably delivered to the client.
The reliability of the map distribution service will be improved.

Embodiment 14 FIG. Also in this embodiment, a description will be given of a discarding process realized by the map data transmitting apparatus and the relay station in consideration of the priority of the packet.
First, as in the thirteenth embodiment, when storing a part in a data delivery packet, the packet generation unit 14 of the map data transmitting apparatus stores the priority set by the priority setting unit 11 for each part in each packet. . That is, a packet storing a part to which a high priority is set is given a high priority. The priority setting unit and the procedure for setting the priority are the same as those described in the first embodiment. Also, the method of storing the priority in the data delivery packet is arbitrary,
For example, it is conceivable to describe the priority in the header portion of the data delivery packet. When the data delivery packet generated in this way is transmitted, the relay station discards the packets with the lower priority given to the packets according to the buffer availability. In the relay station, the packet discard rate control unit (not shown) sets the discard rate of the packets to be discarded among the packets received by the relay station in accordance with the buffer availability of the relay station and the priority of the packets. The discard rate is controlled in accordance with the change rate of the vacancy status. As a method of setting the discard rate at each relay station, for example, the higher the priority of a packet, the lower the discard rate at the relay station. A packet having a priority equal to or higher than a certain value of the packet priority is not discarded at all, but a packet having a priority equal to or lower than the value is discarded at a discard rate according to the availability of the buffer. Packets to be discarded are discarded at the same discard rate regardless of priority. The packet loss rate set in this way is adjusted according to the buffer availability of the relay station so that data with higher real-time properties is preferentially distributed. The higher the vacancy rate of the buffer in the relay station, the lower the packet discard rate is set, and the lower the vacancy rate of the buffer is, the higher the packet discard rate is set. When the overall discard rate is set to be higher again, the increment of the discard rate may be set higher for packets with lower priority. Also, when resetting the overall discard rate to a lower value, the drop rate of the discard rate may be increased for packets with higher priority. Furthermore, the setting of the discard rate may be changed according to the degree to which the empty rate of the buffer changes and the change rate. In this case, if the empty rate of the buffer suddenly drops, the increase rate of the discard rate is increased and the discard rate is reset. Therefore, even if the vacancy rate of the buffer at a certain point in time is the same, the greater the rate of change, the greater the degree of change in the discard rate. The higher the buffer vacancy rate, the lower the discard rate. The higher the change rate at which the vacancy rate increases, the smaller the discard rate is set. Also, the smaller the vacancy rate of the buffer of the relay station, the larger the discard rate is set. The higher the change rate at which the vacancy rate decreases, the greater the discard rate is set even for the same vacancy rate.

This indicates a situation in which the congestion situation of the network is getting worse when the vacancy rate gradually decreases. Therefore, by increasing the packet discard rate in accordance with the above-mentioned priority, In order to prevent an abnormal situation in which a high-priority packet is not delivered from the relay station at all and a packet loss occurs even though low-priority data is being delivered from the relay station rapidly, Set the discard rate in consideration of. If the vacancy rate decreases, it indicates a situation where the number of packets that are going to enter the buffer of the relay station is gradually increasing. Therefore, if the discard rate is not increased, the buffer is clogged. If the buffer overflows, all packets that have reached the relay station are discarded thereafter. In order to avoid such a situation as much as possible, raise the disposal rate,
No matter how much a high priority packet is congested, the situation is such that the probability of passing through a relay station is higher than other low priority packets. When the rate of change at which the vacancy rate decreases becomes large in order to cope with the change immediately, it indicates that the number of packets reaching the buffer is increasing rapidly. The rate of change is made larger than when the rate of change is small. This makes it possible to avoid a situation in which the buffer overflows and all the packets arriving at the relay station are dropped in response to a rapid increase in the number of packets. Moreover, it is possible to easily realize packet discarding according to the set priority.

Embodiment 15 FIG. In the present embodiment, a description will be given of a map data priority setting method for appropriately displaying and minimizing the amount of data required for the display in accordance with the display density of the display screen of the mobile terminal. As the area to be displayed on the map assigned to the unit pixel on the display screen is larger, it becomes more difficult to accurately display the map parts existing in the display area. Although the map data is detailed, there arises a problem that the detailed map data cannot be reflected on the display. Therefore, the server calculates the size (display density) of the map display area occupied per unit pixel from the display screen size and resolution of the viewer of the mobile terminal that has issued the map transmission request, and displays the map parts on the screen. Calculate the degree of reflection (reflection degree). The priority of the map parts is reset according to the magnitude of the degree. The degree of reflection indicates the degree to which a map part shape is displayed according to data when the map part is displayed. It is said that the more the shape is displayed as the data, the greater the degree that it can be reflected,
When a map part has a distorted shape and a reduced display, the greater the degree of the distortion / reduction, the smaller the reflection degree. As shown in FIG. 41, when map parts of the same shape are displayed with 16 pixels (Case 1)
When compared with the case of displaying with 192 pixels (case 2), case 2 is said to have a higher degree of reflection on display. Therefore, a map part having a higher degree of reflection on the display is easier for the user to see, so that a higher priority is set, and a map part with a lower degree of reflection is distorted in shape and has a distorted display, so that a lower priority is set.

In the present embodiment, a method of setting the priority of parts based on the display density of map data displayed on the display screen of the mobile terminal will be described. The display density here is the area (data amount) of a display target area per unit display screen pixel. In the present embodiment, the display unit pixel number detection unit and the display density detection unit (both not shown)
To calculate the above-mentioned reflection degree. The display unit pixel number detection unit detects the number of vertical and horizontal unit pixels forming the display screen of the display unit. A display area area per unit pixel (display density) is detected from the number of vertical and horizontal pixels of the display screen detected by the display pixel number detection section and a display area area of a map displayed on the display screen. I do. Therefore, in the transmission order priority setting unit, the priority is set higher for data having a higher degree of reflection, that is, for map data that can be displayed more accurately, and the transmission order is set higher. A method of calculating the degree of reflection will be described. The transmission order priority setting unit determines the degree of reflection using the calculated data, and receives the result, and sets a transmission priority indicating transmission priority. The unit pixel number assigned to the map data displayed on the display unit based on the display density per unit pixel of the display unit detected by the display density detection unit, according to the shape of the part shown in the map data The data of the unit pixel number necessary for display is calculated by the assigned unit pixel number detection unit. Are calculated by the necessary unit pixel number detecting unit. The transmission order priority setting unit transmits the map data based on a ratio between the number of allocated unit pixels detected by the allocated unit pixel number detection unit and the required unit pixel number detected by the required unit pixel number detection unit. Set the priority for setting the order. It is said that the closer the value of / is to 1, the greater the degree of reflection, and the closer to 0, the lower the degree of reflection. Based on this ratio value, the map data having a larger ratio value is set to have a higher priority and the transmission order is set to a higher rank. The reflection degree calculated in this way indicates the degree to which the map part shape is displayed according to the data of the map part when the graphic parts (map parts) constituting the map are displayed, and thus the user wants to see the reflection degree. It can also be used as an index indicating the degree. In addition, the display quality is the same regardless of whether map data (parts having a low degree of reflection) that cannot be reflected on the screen display is present during the display processing. In a system in which map data is transmitted from a server to a mobile terminal and displayed on the mobile terminal, the display quality does not change even if the map data that cannot be reflected on the screen display is not transmitted. Therefore, the degree of detail of the map data is adjusted according to the degree of reflection, and the priority of the constituent data constituting the map data is reset. Next, a method for adjusting the degree of detail of the map parts according to the degree of reflection will be described. The adjustment of the degree of detail means whether or not to transmit the attribute information constituting the part, or when transmitting, the transmission priority, that is, according to the congestion state of the network and the communication network, The transmission priority is set between the pieces of attribute information in accordance with the priority set for itself. The transmission order of the attribute information to be transmitted is set according to the degree of congestion, and the attribute information not to be transmitted at that time is also specified. In addition, the transmission order, data not to be transmitted, and the like are set according to the priority set for the parts.
For example, in the case of one road part having a plurality of interpolation points, if the distance between the nodes is larger than the actual map distance corresponding to the diameter of the pixel, each node is set as a transmission target, and the larger the priority, the higher the priority. Set higher. If the diameter is equal to or smaller than the diameter of the pixel, a priority is set not to be a transmission target. The priority of the interpolation point node as attribute information of the part is set. If the road width of the road part is smaller than the pixel diameter, accurate display cannot be performed.
The display priority is set lower depending on the degree of distortion. Also, POI information, gas stations, traffic lights, parking lots,
If the pixel required for displaying the name character string or the like cannot be secured at the minimum, the pixel is not displayed in principle. If there is enough space in the pixels, the information is the size specified by the map creator,
Display at the specified location. If the minimum required number of pixels cannot be secured, it is not displayed in principle. However, if the display pixels can be secured at the expense of other display, an empty area is searched for and displayed by giving priority to parts having higher priority. The priority is set in accordance with the degree to which the number of pixels required for displaying the part after the adjustment of the degree of detail can be secured.

Next, it is assumed that the priority setting based on the display density and the degree of reflection is effective, for example, as shown in FIG. 29, in a case where a map is displayed three-dimensionally looking down a diagonally vertically downward direction. explain. FIG. 29A shows a state in which the map is viewed from obliquely above from the X-axis-Y-axis direction. FIG. 29B illustrates a state in which the map is looked down diagonally from the X-axis-Z-axis direction. The areas of the map that enter the field of view when looking down on the map from the viewpoint position are the areas A and B shown in FIG. 29A, and the area A is displayed at the top of the display screen as shown in FIG. 29B. That is, the area B is displayed at the lower part of the display screen. That is, the map data transmission device manages the area A as map data displayed at the top of the display screen, and manages the area B as map data displayed at the bottom of the display screen. As shown in FIG. 29, when the map is viewed obliquely vertically downward, the display target area assigned to each pixel on the display screen has the same horizontal pixels on the screen, In the lower pixel, FIG.
As shown in (a), the map area that must be displayed per unit pixel is different. That is, the width in the Y-axis direction in FIG. 29A is the same in the regions A and B, but the width in the X-axis direction is larger in the region A than in the region B. On the other hand, since the upper part of the display screen displaying the area A and the lower part of the display screen displaying the area B have the same area, the map area which must be displayed per unit pixel differs between the upper part and the lower part of the display screen. When the map is viewed from the direction as shown in FIG. 29, the display density is higher at the upper pixel of the display screen. Therefore, the degree of detail of the area A displayed by the pixels having the high display density is set lower than the degree of detail of the area B displayed by the pixels having the low display density. A high display density means that a display target area that must be displayed per unit pixel is wide. Therefore, it is difficult or impossible to display detailed parts in a dense place. It is impossible to display the original model due to degeneration. Thus, even if detailed data is transmitted, data that is not reflected on the display is not transmitted, so that the drawing speed and transmission time can be reduced. As long as the resolution of the display screen does not change, the resolution of the pixel does not change. The larger the amount of detailed data that is displayed where the resolution of the pixel does not change, the more pixels are insufficient, the more the display becomes impossible, and the display becomes distorted, degenerated, and uncomfortable. In order to improve the processing efficiency, the display screen is divided into a plurality of pixels by grouping pixels having similar display density values instead of a pixel unit. The average value of the display densities of the divided windows is determined by the average value obtained by dividing all the display target areas allocated to the pixels included in the divided window by the number of pixels constituting the divided window. In an average display density detection unit (not shown), the display unit is divided for each portion where the display density is similar to form a divided window, and the map data displayed in the divided window is displayed per unit pixel. An average display density, which is a data amount, is detected for each divided portion of the display unit. Since this average display density is invariable unless the viewpoint position and line-of-sight direction are changed, only the average display density for each divided window is calculated at startup, initialization, or when the viewpoint position and line-of-sight direction are changed. Is fine. The degree of detail of the map according to the average display density is determined for each divided window.

A method of detecting the average display density in the average display density detection section will be described with reference to FIG.
FIGS. 29A and 29B show two display screens as described above.
This is an example in which the map is divided into two divided windows, the degree of detail of the map to be displayed in each window is individually determined, and the map is displayed. In the upper part of the display screen, the map of the area A shown in FIG. 29A is the display target area. In the lower part of the display screen, the map of the area B is a display target area. Therefore, the upper and lower portions of the display screen have the same area, but the display target area, which must be displayed at the upper portion of the screen, is much larger, as shown in FIG. That is, the average display density at the top of the screen is higher. Therefore, in consideration of the average display density, the degree of reflection on the display is determined, and the optimum level of detail is determined. The degree of detail refers to the degree of detail and sophistication of map part data used when calculating the degree of reflection. When the level of detail is designated, the part data corresponding to the level of detail is selected, the pixels necessary to display the selected data are calculated, and the degree of reflection is calculated. Adjusting the degree of reflection by changing this level of detail means reducing the distribution data and various details of the part to reflect the priority set by another priority setting standard The degree of reflection is adjusted by selecting the optimum level of detail from the data corresponding to the levels. By not distributing detailed data that is not reflected on the display, the amount of distribution data can be reduced. Also, for example, a part set with a high priority in the priority setting has a low reflection level, and thus has a low priority set. In other words, it is possible to solve the problem that the required timing is missed. The degree of reflection on the display means that the degree of reflection (reflection degree) increases as the part is displayed in a complete form without degenerating the shape as the data of the parts. In this way, a part having a higher degree of reflection is positioned as a part to be viewed and displayed, and the priority is set higher. The transmission order priority setting unit sets the transmission order of the map data based on the average display density detected by the average display density detection unit. The priority setting method indicating the transmission order is the same as the priority setting based on the reflection degree. By using such a priority setting method, for example, when displaying a two-dimensional vector map in a manner of looking down from a viewpoint position as shown in FIG. You have to calculate what is displayed and set a transmission schedule. Therefore, the display scheduled time at which each map part starts to be displayed is calculated for each of the divided windows to be displayed. The transmission priority is calculated for each divided window by calculating the display density and the degree of reflection and using the calculated degree of reflection. However, the priority setting rules for the parts that the user wants to see and display (already described in the above embodiment)
Are set based on common rules. The parts that exist in the area A in FIG. 29A and are displayed in the upper part of the display screen have priority setting based on the priority setting rule set according to the display density in the upper part of the display screen. And
Calculate the scheduled display time at which the display window starts to be displayed in the divided window at the top of the display screen. These data are classified into first type and second type data, and the transmission order is set based on the scheduled display time and the priority, respectively, to set the transmission schedule. Thereafter, a transmission process is performed according to the transmission schedule. At the same time, a transmission target area for selecting a map part to be displayed in the lower divided window is calculated, and the display density and reflection degree of the divided window are calculated and the priority is set for the map part in the transmission target area. However, the map parts transmitted for display at the upper part of the display screen or the partial data constituting the map parts are not transmitted.
The transmission schedule setting and transmission processing performed on the map parts for which the priorities have been set in this manner are the same. As described above, the processing shown in the step of selecting a transmission target area, the step of setting a priority, the step of setting a transmission schedule, and the step of transmitting processing are performed for each divided window of the display screen. Rules (tables) that indicate parts to be displayed with priority set according to display density and reflectivity
The priority is set by combining priority rules according to the user's request and purpose of use based on priority rules closer to the route, priority rules closer to the display screen, and the like. For example, at a certain display density, roads below the national highway are not displayed. In addition, in the case of a certain display density, the priority is set according to a rule describing how to display according to the display density, such as not displaying a character name such as a place name. Further, the priority of the map parts to be displayed is reset according to the degree of reflection. Map parts with a higher degree of reflection have higher priorities.

In the case of performing display in which the display density differs depending on the pixels on the display screen, the display density of the pixels on the display screen,
By setting priorities in combination with priority setting rules (tables) set according to the reflectivity of parts, user requirements, purpose of use, visibility, reachability, etc., two-dimensional
Map parts in the case of displaying a two-dimensional vector map can be efficiently selected by mechanical processing of priority setting.

[0156]

According to the invention of the first embodiment, the transmission schedule is set based on the scheduled display time.
Transmission can be performed in consideration of the time when display is required for each part, and transmission of parts with high real-time properties can be flexibly performed.

According to the second embodiment of the present invention, it is possible to calculate the display scheduled time with higher accuracy from the movement status information received from the mobile terminal, and it is possible to set a transmission schedule with higher accuracy.

According to the third embodiment of the present invention, the transmission schedule is set based on the transmission processing completion deadline, the transmission processing completion time, the display end time, and the transmission end time. It can be done flexibly. In addition, when there is a large amount of time before the display, the transmission can be performed during a vacant time until the scheduled display time. Further, when all the map data to be displayed cannot be transmitted by the scheduled display time, data having a certain priority or higher is transmitted with priority so that it is always displayed. In addition, the map can be reused.

According to the invention of the fourth embodiment, it is possible to distribute the transmission of map data having a large data amount by pre-reading the map data, and to reduce the amount of transmission processing when transmitting map data having a large data amount. Becomes

According to the fifth embodiment of the present invention, the currently displayed map is temporarily interrupted, and the map of the designated area (a destination or a point far from the previously displayed point) is displayed. When displaying a map, or when displaying the point specified for the first time when the system is started, the map data that was the display target area of the display screen may be used for data related to the route, data close to the current location, The distribution priority of near data can be set high and distributed to the mobile terminal.

According to the invention of the sixth embodiment, the ratio between the first type data and the second type data can be adjusted according to the congestion situation, so that optimal transmission can be performed according to the congestion situation.

According to the invention of the seventh embodiment, even when the congestion situation changes abruptly, it is possible to realize a smooth change without a sudden change in the degree of detail of the display.

According to the inventions according to the eighth to tenth embodiments,
Since the data delivery packet is transmitted without establishing a connection, transmission with high real-time property can be performed.
In addition, since retransmission of important data is guaranteed, the reliability of transmission can be ensured.

According to the eleventh embodiment, it is possible to select an optimum communication line from a plurality of communication lines according to the real-time property required for data. For this reason, even when a plurality of users use the map data transmitting device simultaneously, all the transmission of the first type data that requires real-time properties is performed through the high-speed data communication path. For this reason, even when used by many users, the first type data having high real-time property can be always delivered to each of the many users at high speed.

According to the twelfth embodiment, the necessity of retransmission is increased due to the congestion of the communication channel. However, even if it is difficult to retransmit all the packets,
Retransmission is preferentially performed from the parts with higher priority. For this reason, even when congestion is large, display according to the priority can be performed on the display screen of the mobile terminal.

According to the thirteenth embodiment, since the relay station discards packets based on the priority set for each packet, data with high priority is reliably discarded by the user without being discarded by the relay station. Can be delivered.

According to the invention of the fourteenth embodiment, since the relay station discards packets based on the priority and the buffer available rate set for each packet, data with high priority is not discarded by the relay station. It can be reliably delivered to the user.

According to the fifteenth embodiment, the priority is set in accordance with the degree to which each part is displayed on the display screen of the mobile terminal. This makes it possible to display map data that is easy for the user to see.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a map data transmitting device according to the present invention.

FIG. 2 is a diagram showing a static priority setting table.

FIG. 3 is a flowchart illustrating a procedure for setting a transmission schedule.

FIG. 4 is a diagram showing a procedure for selecting a transmission target area.

FIG. 5 is a diagram showing a priority setting table according to route visibility;

FIG. 6 is a diagram showing each part in map data.

FIG. 7 is a diagram showing a state where parts are assigned to a route visibility-based priority setting table.

FIG. 8 is a diagram showing a guide route distance-based priority setting table and a current position distance-based priority table;

FIG. 9 is a diagram showing a transmission order of each part.

FIG. 10 is a diagram showing a procedure for detecting a scheduled display start time.

FIG. 11 is a diagram showing a procedure for detecting a scheduled display start time.

FIG. 12 is a flowchart illustrating a procedure for setting a transmission schedule.

FIG. 13 is a flowchart illustrating a procedure for setting a transmission schedule.

FIG. 14 is a diagram showing the transmission order of each part.

FIG. 15 is a diagram showing a transmission order of each part.

FIG. 16 is a diagram showing the transmission order of each part.

FIG. 17 is a diagram showing a procedure for detecting a display end time.

FIG. 18 is a diagram showing the transmission order of each part.

FIG. 19 is a diagram showing a procedure of prefetch transmission.

FIG. 20 is a diagram showing a procedure of packet generation and packet transmission.

FIG. 21 is a diagram showing a transmission content notification packet and a data delivery packet.

FIG. 22 is a diagram showing a retransmission procedure.

FIG. 23 is a diagram showing a transmission content notification packet and a data delivery packet.

FIG. 24 is a diagram showing a transmission content notification packet and a data delivery packet.

FIG. 25 is a diagram showing a first type packet final notification packet and a transmission end notification packet.

FIG. 26 is a diagram showing a state of relaying a packet by a relay station.

FIG. 27 is a diagram showing a state of relaying a packet by a relay station.

FIG. 28 is a diagram showing a configuration example of a composite data delivery packet.

FIG. 29 is a diagram showing a priority setting method based on a display screen size according to the present invention.

FIG. 30 is a functional block diagram of a conventional deformed map creating device.

FIG. 31 is a functional block diagram of a conventional drawing data management device.

FIG. 32 is a transmission sequence diagram of a conventional map data transmission packet.

FIG. 33 is a diagram showing a situation in which a conventional relay station discards packets.

FIG. 34 is a diagram showing rearrangement of the transmission order of the first type data and the second type data.

FIG. 35 is a diagram showing rearrangement of the transmission order of the first type data and the second type data.

FIG. 36 is a diagram showing a map data transmitting device and a mobile terminal according to the second embodiment.

FIG. 37 is a diagram showing a map data transmitting device and a mobile terminal according to Embodiment 12.

FIG. 38 is a diagram showing a transmission target area and a display target area.

FIG. 39 is a diagram showing classification of first type data and second type data.

FIG. 40 is a diagram showing the timing of switching the transmission schedule.

FIG. 41 is a diagram showing the degree of reflection given to display.

[Explanation of symbols]

1 map data transmission device, 2 map database unit, 3
Parts storage section, 4 road traffic / accident construction information section, 5P
OI information section, 6 user information database section, 7 transmission area selection section, 8 congestion status detection section, 9 moving speed detection section, 10 section reference setting section, 11 priority setting section, 1
101 static priority setting unit, 1102 dynamic priority setting unit, 12 time detection unit, 13 transmission schedule setting unit, 14 packet generation unit, 15 packet transmission unit, 1
8 retransmission level setting unit, 19 transmission schedule adjustment unit,
20 relay station, 30 mobile terminal, 31 retransmission request transmission section,
32 Transmission schedule adjustment request unit.

Continued on the front page F-term (reference) 2C032 HB25 HD03 2F029 AA02 AC02 AC08 AC14 AC16 5H180 BB05 BB15 FF12 FF22 5K067 AA14 AA28 CC08 DD30 FF00 FF03 FF05 FF23 GG06 HH22 HH23 HH28 JJ73 KK15 956 Data transmission device, map data relay station, map data transmission system, map data transmission method, map data transmission and relay method, computer-readable recording medium recording a program for causing a computer to execute the map data transmission method, and map Computer-readable recording medium recording a program for causing a computer to execute a data transmission and relay method

Claims (73)

[Claims] 1. A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein the map data transmitting apparatus comprises a display unit for displaying the map data. A map data transmitting device for transmitting data, a transmission schedule setting unit for setting a transmission schedule for transmitting the map data to the map data receiving device; and the map data receiving device displaying the map data on the display unit. A transmission schedule setting unit configured to set the transmission schedule based on the display schedule time detected by the display schedule time detection unit. A map data transmitting device characterized by performing the following. 2. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of a transmission order of the map data, wherein the transmission schedule setting unit includes 2. The map data transmitting apparatus according to claim 1, wherein the transmission schedule is set based on the detected scheduled display time and the transmission order priority set by the transmission order priority setting unit. 3. The map data transmitting apparatus further includes a division criterion setting unit that sets a division criterion for dividing the map data into a plurality of groups, wherein the transmission schedule setting unit is configured to perform the division criterion setting. The map data is divided into a plurality of groups based on the division criteria set by a unit, and the transmission schedule setting unit sets the transmission schedule for each of the groups.
2. The map data transmitting device according to 1. 4. The classification criterion setting unit dynamically changes the classification criterion, and the transmission schedule setting unit converts the map data based on the classification criterion dynamically changed by the classification criterion setting unit. 4. The map data transmitting device according to claim 3, wherein the map data transmitting device is divided into a plurality of groups. 5. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of the transmission order of the map data, wherein the division criterion setting unit is configured to be a transmission order priority setting unit. The map data transmitting apparatus according to claim 3, wherein the classification criterion is set based on the transmission order priority set by the following. 6. The transmission schedule setting unit, wherein the map data is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. And a retransmission assurance data group that ensures that the map data is always retransmitted to the map data receiving device, and the map data receiving device does not normally receive the map data when the map data receiving device does not normally receive the map data. The map data transmitting apparatus according to any one of claims 3 to 5, wherein the map data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission to the map data receiving apparatus. 7. A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein the map data transmitting apparatus sets a transmission schedule for transmitting the map data to the map data receiving apparatus. A transmission schedule setting unit, comprising: a transmission time limit detection unit that detects a transmission time limit for transmitting the map data to the map data receiving device, wherein the transmission schedule setting unit detects the transmission time limit detected by the transmission time limit detection unit. A map data transmission device, wherein the transmission schedule is set based on a transmission time limit. 8. The map data transmitting apparatus, wherein the map data transmitting apparatus transmits the map data to a map data receiving apparatus having a display unit for displaying the map data, wherein the map data transmitting apparatus further comprises the map data transmitting apparatus. The data receiving device has a scheduled display time detecting unit that detects a scheduled display time at which the display of the map data is started on the display unit, and the transmission time limit detecting unit detects the display detected by the scheduled display time detecting unit. The map data transmission device according to claim 7, wherein the transmission time limit is detected based on a scheduled time. 9. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of a transmission order of the map data, wherein the transmission schedule setting unit detects the priority by the transmission time limit detection unit. The map data transmission device according to claim 7, wherein the transmission schedule is set based on the transmission deadline set and the transmission order priority set by the transmission order priority setting unit. . 10. The map data transmitting apparatus further includes a transmission process completion time detecting unit that detects a transmission process completion time when the map data transmission process is scheduled to be completed, The setting unit compares the transmission deadline detected by the transmission deadline detection unit with the scheduled transmission processing completion time detected by the scheduled transmission processing completion detection unit, and sets the transmission deadline and the scheduled transmission processing completion time. 9. The map data transmission device according to claim 7, wherein the transmission schedule is set based on a comparison with the map data transmission schedule. 11. The map data which is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data, And a retransmission assurance data group that ensures that the map data is always retransmitted to the map data receiving device, and the map data receiving device does not normally receive the map data when the map data receiving device does not normally receive the map data. The map data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission to the map data receiving device, and the transmission schedule is set for each of the retransmission guaranteed data group and the retransmission non-guaranteed data group. The map data transmitting device according to any one of claims 7 to 10. 12. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of a transmission order of the map data, wherein the transmission schedule setting unit includes the transmission order priority setting unit. And dividing the map data into the retransmission guaranteed data group and the retransmission non-guaranteed data group based on the transmission order priority set by the following.
2. The map data transmitting device according to 1. 13. The map data transmitting apparatus further includes a transmission process completion time detecting unit that detects a transmission process completion time when the map data transmission process is to be completed, wherein the transmission schedule The setting unit compares the transmission time limit detected by the transmission time limit detection unit with the scheduled transmission processing completion time detected by the scheduled transmission processing time detection unit, and performs the transmission at an earlier time than the transmission time limit. Classifying the map data having the scheduled processing completion time into the retransmission guarantee data group, and classifying the map data having the transmission processing completion time later than the transmission deadline into the retransmission non-guaranteed data group. The map data transmitting device according to claim 11, wherein 14. The map data transmitting apparatus further includes a transmission processing completion time detecting unit that detects a transmission processing completion time, which is a time when the map data transmission processing is to be completed, and a transmission of the map data. A transmission processing end time detection unit that detects a transmission processing end time for ending the processing, wherein the transmission schedule setting unit detects the transmission processing completion time detected by the transmission processing completion time detection unit and the transmission processing completion time The transmission schedule is set based on a comparison between the transmission process end time detected by the end time detection unit and the scheduled transmission process completion time and the transmission process end time. The described map data transmission device. 15. The transmission schedule setting unit compares the transmission processing completion time detected by the transmission processing completion time detection unit with the transmission processing end time detected by the transmission processing completion time detection unit. 15. The map data transmitting apparatus according to claim 14, wherein the transmission schedule is set only for the map data having a scheduled transmission processing completion time earlier than the transmission processing ending time. 16. The transmission schedule setting unit compares the transmission processing completion time detected by the transmission processing completion time detection unit with the transmission processing end time detected by the transmission processing completion time detection unit. 15. The map data transmission according to claim 14, wherein a transmission schedule to be transmitted after a lapse of the transmission end time is set for map data having a scheduled transmission processing completion time later than the transmission processing end time. apparatus. 17. The map data receiving apparatus is a map data transmitting apparatus for transmitting map data to a map data receiving apparatus having a display unit for displaying the map data, wherein the map data transmitting apparatus further comprises: The data receiving device includes a display end time detecting unit that detects a display end time that is a time when the display of the map data on the display unit ends, and the transmission process end time detecting unit is detected based on the display end time. 17. The map data transmission device according to claim 14, wherein the transmission processing termination timing is detected based on the display termination timing. 18. The transmission schedule setting unit according to claim 1, wherein the timing for setting the transmission schedule is dynamically changed based on a data amount of map data to be transmitted to the map data receiving device. 8. The map data transmitting device according to any one of 7. 19. The map data transmitting apparatus further includes: a congestion state detecting unit that detects a congestion state of a communication path used by the map data transmitting apparatus for transmitting the map data; The map data transmission device according to claim 1, further comprising: a transmission schedule adjustment unit configured to reset a transmission schedule of the map data set by the transmission schedule setting unit based on the transmission schedule setting unit. 20. A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein the map data transmitting apparatus has a plurality of communication paths used by the map data transmitting apparatus for transmitting the map data. The map data transmitting device has a congestion status detection unit that detects a congestion status of the communication route, and the map data from a plurality of the communication routes based on the congestion status detected by the congestion status detection unit. And a communication path setting switching unit for dynamically setting the communication path used for transmission of the map data. 21. The map data according to claim 20, wherein the communication route setting switching unit sets the communication route to be used for transmitting the map data from a plurality of the communication routes for each of the map data. Transmission device. 22. A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein: a transmission schedule setting unit for setting a transmission schedule for transmitting the map data to the map data receiving apparatus; A packet generation unit configured to generate a data delivery packet storing the map data according to the transmission schedule set by the transmission schedule setting unit; and the data delivery packet generated by the packet generation unit set by the transmission schedule setting unit. A packet transmitting unit for transmitting to the map data receiving device according to the transmission schedule. 23. The map data receiving device, wherein the map data receiving device does not normally receive the data delivery packet, and the map data receiving device does not receive the data delivery packet normally. 23. The map data transmitting device according to claim 22, wherein the map data transmitting device retransmits the data to a receiving device. 24. The map generating unit, when the map data receiving device does not normally receive the data delivery packet, the map data receiving device does not always receive the data delivery packet that has not been normally received by the map data receiving device. A retransmission guarantee packet that guarantees retransmission to the data receiving device; and the data delivery packet that was not normally received by the map data receiving device when the map data receiving device did not receive the data delivery packet normally. And a retransmission non-guaranteed packet that does not guarantee retransmission to the map data receiving device.The packet transmission unit starts transmission of the retransmission non-guaranteed packet after transmission of the retransmission guarantee packet is completed. 23. The map data transmission device according to claim 22, wherein: 25. The map data transmitting apparatus according to claim 24, wherein the packet transmitting section starts transmitting the retransmission non-guaranteed packet after retransmission of the retransmission guaranteed packet is completed. 26. The map according to claim 22, wherein the packet transmitting unit transmits the data delivery packet without establishing a connection with the map data receiving device. Data transmission device. 27. A transmission method for transmitting the data delivery packet without establishing a connection with the map data receiving device, wherein the packet transmitting unit establishes a connection with the map data receiving device. 26. The map data transmitting device according to claim 22, wherein any of the transmitting methods for transmitting the data delivery packet can be selected. 28. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of a transmission order of the map data, wherein the packet generation unit includes a transmission order priority setting unit. Setting the set transmission order priority to the data delivery packet, wherein the packet transmitting unit retransmits the data delivery packet based on the transmission order priority set to the data delivery packet. 24. The map data transmitting device according to claim 23, wherein: 29. The map data transmitting apparatus further includes a frequency at which the packet transmitting unit retransmits the data delivery packet with respect to a number of times the map data receiving apparatus does not normally receive the data delivery packet. A retransmission level setting unit that sets a retransmission level indicated in the data delivery packet to the data delivery packet, wherein the packet transmission unit sets the data delivery packet based on the retransmission level set in the data delivery packet by the retransmission level setting unit. The map data transmitting apparatus according to claim 23, wherein retransmission is performed. 30. The map data transmitting apparatus further includes a transmission order priority setting unit that sets a priority of the transmission order of the map data, wherein the retransmission level setting unit includes the transmission order priority setting unit. 30. The map data transmitting apparatus according to claim 29, wherein the retransmission level is set in the data delivery packet based on the transmission order priority set by the following. 31. The packet generation unit assigns a sequence number indicating a transmission order of the data delivery packet to the data delivery packet, and the packet creation unit assigns a retransmission guarantee sequence number assigned to the retransmission guarantee packet to the data delivery packet. 25. The map data transmitting device according to claim 24, wherein the map data transmitting device generates a sequence number notification packet for notifying the map data receiving device of a retransmission non-guaranteed sequence number assigned to the retransmission non-guaranteed packet. 32. The packet generating unit according to claim 31, wherein the packet generation unit generates a sequence number notification packet for notifying the map data receiving device of a retransmission guarantee sequence number given to the retransmission guarantee packet. Map data transmission device. 33. The packet generator, wherein a sequence number notification packet for notifying the map data receiving device of a sequence number given to a data transmission packet transmitted first, and that a retransmission guarantee packet has been transmitted are completed. Generating a retransmission guarantee packet transmission end notification packet for notifying the map data receiving device and a retransmission non-guaranteed packet transmission end notification packet for notifying the map data receiving device that the retransmission non-guaranteed packet has been transmitted. 32. The map data transmitting device according to claim 31, wherein 34. The map data transmitting apparatus further includes a packet transmitting unit that transmits the data delivery packet generated by the packet generating unit, wherein the packet transmitting unit transmits the sequence to the map data receiving apparatus. The map data transmitting device according to any one of claims 31 to 33, wherein a number notification packet is transmitted, and the map data receiving device transmits the data delivery packet after receiving the sequence number notification packet. 35. The map data transmission device according to claim 22, wherein the packet generation unit generates the data delivery packet storing the map data and an identifier indicating the identity of the map data. . 36. A map data transmitting apparatus for transmitting map data to a map data receiving apparatus for receiving map data, wherein: a transmission reliability priority setting for setting a priority of transmission reliability of the map data to the map data. And a packet generation unit that generates a data delivery packet storing the map data, wherein the packet generation unit has different transmission reliability priorities set by the transmission reliability priority setting unit. A map data transmission device, comprising: a composite packet generator for generating a composite data delivery packet storing a plurality of map data. 37. The composite packet generator stores the map data set with the higher transmission reliability priority at the beginning of the composite data delivery packet, and sets the transmission reliability priority lower. 37. The map data transmitting apparatus according to claim 36, wherein the map data is stored at the end of the composite data delivery packet. 38. A map data transmission system, comprising: a map data transmission device that transmits a data delivery packet storing map data to a map data reception device; and a map data relay station that relays the transmission of the data delivery packet. The map data transmitting device includes: a transmission reliability priority setting unit configured to set the transmission reliability priority of the map data to the map data; and the transmission reliability priority different by the transmission reliability priority setting unit. A composite packet generation unit that generates a composite data delivery packet that stores a plurality of map data sets, wherein the map data relay station has a packet discarding unit that discards the data delivery packet, The discarding unit is more reliable than other map data among the plurality of map data stored in the composite data delivery packet. A map data transmission system characterized in that map data set with low priority of sex is preferentially discarded. 39. The composite packet generator stores the map data set with the higher transmission reliability priority at the beginning of the composite data delivery packet, and sets the transmission reliability priority lower. The map data is stored at the end of the composite data delivery packet, and the packet discarding unit of the map data relay station is configured to store the composite data delivery packet among the plurality of map data stored in the composite data delivery packet. 39. The map data transmission system according to claim 38, wherein the map data stored in the tail is preferentially discarded. 40. A map data transmission system, comprising: a map data transmission device that transmits a data delivery packet storing map data to a map data reception device; and a map data relay station that relays the transmission of the data delivery packet. The map data transmitting device always retransmits the data delivery packet that was not normally received by the map data receiving device to the map data receiving device when the map data receiving device did not normally receive the data delivery packet. And a retransmission guarantee packet that guarantees that the data delivery packet is not normally received by the map data receiving device when the map data receiving device does not normally receive the data delivery packet. A non-guaranteed retransmission packet that does not guarantee retransmission to the device Transmitted to the data repeater station, the map data RS, the map data transmission system characterized by relaying the retransmission guarantee packet priority to the retransmission non-guaranteed packet. 41. A map data relay station for relaying transmission of a data delivery packet storing map data, wherein: a buffer unit for temporarily storing the data delivery packet; and the data temporarily stored by the buffer unit. A packet discarding unit for discarding a delivery packet, and a packet discarding rate which is a ratio of discarding of the data delivery packet discarded by the packet discarding unit to all of the data delivery packets temporarily stored in the buffer unit. A map data relay station, comprising: 42. A map data transmitting system comprising: a map data transmitting device for transmitting a data delivery packet storing map data to a map data receiving device; and a map data relay station for relaying the transmission of the data delivery packet. The map data transmitting device, a transmission reliability priority setting unit that sets the transmission reliability priority of the map data to the map data, and a transmission reliability priority set by the transmission reliability priority setting unit. A packet generation unit that generates the data delivery packet storing the set map data, wherein the map data relay station temporarily stores the data delivery packet; and a buffer unit that temporarily stores the data delivery packet. A packet discarding unit that discards the data delivery packet that is temporarily stored; A packet discard rate setting unit that sets a packet discard rate, which is a ratio of discarding of the data delivery packet discarded by the packet discarding unit to all the data delivery packets, wherein the packet of the map data relay station is The discard rate setting part
A map data transmission system, wherein the packet discard rate is set based on the transmission reliability priority set in the map data by the transmission reliability priority setting unit of the map data transmission device. 43. The map data relay station further includes: a maximum data amount of the buffer unit in which the buffer unit can store the data delivery packet, and a maximum data amount of the buffer unit in which the data delivery packet is not stored. A buffer vacancy rate detection unit that detects a buffer vacancy rate that is a ratio, wherein the packet discard rate adjustment unit uses the buffer vacancy rate detected by the buffer vacancy rate detection unit and the transmission reliability priority setting unit. 43. The map data according to claim 42, further comprising: a packet discard rate adjusting unit that adjusts a discard rate of the data delivery packet based on a priority of the transmission reliability set in the map data. Transmission system. 44. A map data transmitting method for transmitting map data to a map data receiving device that receives map data, a transmission map data selecting step of selecting map data to be transmitted to the map data receiving device from the map data. A transmission schedule setting step of setting a transmission schedule for transmitting the map data selected in the transmission map data selection step to the map data receiving device; and A map data transmission method, comprising: a packet generation step of generating a stored data delivery packet; and a packet transmission step of transmitting the data delivery packet generated in the packet generation step. 45. The map data transmitting method, wherein the map data transmitting method is for transmitting map data to a moving map data receiving device which is a moving object. The method according to claim 44, wherein the map data to be transmitted to the moving map data receiving device is selected based on a position and a moving speed of the moving map data receiving device. 46. The map data transmitting method, wherein the map data transmitting method is a map data transmitting method for transmitting map data to a map data receiving apparatus having a display unit for displaying the map data. The map data transmitting method further comprises: A display scheduled time detecting step of detecting a scheduled display time, which is a time at which the data receiving device starts displaying the map data on the display unit, wherein the transmission schedule setting step includes the display scheduled time detecting step 45. The map data transmission method according to claim 44, wherein the transmission schedule is set based on the scheduled display time detected by the method. 47. The map data transmission method further includes a transmission order priority setting step of setting a priority of the transmission order of the map data, wherein the transmission schedule setting step includes a step of: 47. The map data transmission method according to claim 46, wherein the transmission schedule is set based on the detected scheduled display time and the transmission order priority set in the transmission order priority setting step. 48. The transmission schedule setting step, wherein the map data is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. And a retransmission assurance data group that ensures that the map data is always retransmitted to the map data receiving device, and the map data receiving device does not normally receive the map data when the map data receiving device does not normally receive the map data. The map data transmission method according to claim 44, wherein the map data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission to the map data receiving device. 49. The map data transmitting method further includes a transmission deadline detecting step of detecting a transmission deadline for transmitting the map data to the map data receiving device, wherein the transmission schedule setting step comprises: The transmission schedule is set based on the transmission deadline detected in the detection step.
4. The method for transmitting map data according to item 4. 50. The map data transmission method, further comprising: a transmission processing completion time detecting step of detecting a transmission processing completion time when the map data transmission processing is scheduled to be completed; and transmitting the map data. A transmission processing end time detection step of detecting a transmission processing end time for ending the processing, wherein the transmission schedule setting step includes the transmission processing completion time detected by the transmission processing completion time detection step and the transmission processing completion time. 45. The transmission schedule is set based on a comparison between the scheduled completion time of the transmission process and the termination time of the transmission process, by comparing the transmission process end time detected by the process termination time detection step. Map data transmission method described in. 51. The map data transmitting method according to claim 44, wherein, in the packet transmitting step, the data delivery packet is transmitted without establishing a connection with the map data receiving device. 52. The packet generating step adds a sequence number indicating a transmission order of the data delivery packet to the data delivery packet, and the packet generation step allows the map data receiving device to normally execute the data delivery packet. A retransmission guarantee sequence number assigned to a retransmission guarantee packet that guarantees that the data delivery packet not normally received by the map data receiving device when not received is always retransmitted to the map data receiving device; If the map data receiving device does not receive the data delivery packet normally, the retransmission non-guaranteed does not guarantee that the data delivery packet that has not been normally received by the map data receiving device will be retransmitted to the map data receiving device. The retransmission non-guaranteed sequence number given to the packet and the map data Map data transmission method according to claim 44, wherein the generating a sequence number notification packet to notify the data receiving apparatus. 53. A map data transmission and relay method, comprising: a map data transmission method for transmitting a data delivery packet storing map data to a map data receiving device; and a map data relay method for relaying the transmission of the data delivery packet. The map data transmission method, wherein: a transmission reliability priority setting step of setting the transmission data priority of the map data to the map data; and the transmission reliability different by the transmission reliability priority setting step. A composite packet generation step of generating a composite data delivery packet storing a plurality of map data sets of priorities, and the map data relay method has a packet discarding step of discarding the data delivery packet, The packet discarding step includes a step of discarding the plurality of map data stored in the composite data delivery packet. A map data transmission / relay method characterized by preferentially discarding map data set to have a lower transmission reliability priority than other map data. 54. The composite packet generating step of the map data transmitting method, wherein the map data set with a high priority of the transmission reliability is stored at the beginning of the composite data delivery packet, Storing the map data set to a low priority at the end of the composite data delivery packet, wherein the packet discarding step of the map data relaying method includes: 54. The map data transmission and relay method according to claim 53, wherein the map data stored at the end of the composite data delivery packet is preferentially discarded. 55. A computer-readable medium having recorded thereon a program for causing a computer to execute a map data transmission method for transmitting map data to a map data receiving device for receiving map data, wherein the data transmission method comprises: A transmitting map data selecting step of selecting map data to be transmitted to the map data receiving apparatus from the map data; and setting a transmission schedule for transmitting the map data selected in the transmitting map data selecting step to the map data receiving apparatus. A transmission schedule setting step, a packet generation step of generating a data delivery packet storing the map data according to the transmission schedule set by the transmission schedule setting step, and the data generated in the packet generation step A computer-readable recording medium storing a program for executing the map data transmission wherein the computer further comprising a packet transmission step of transmitting the transmission packet. 56. The map data transmitting method, wherein the map data transmitting method is for transmitting map data to a moving map data receiving device which is a moving object, and wherein the transmitting map data selecting step includes the step of: 56. A computer for executing the map data transmitting method according to claim 55, wherein the map data to be transmitted to the moving map data receiving device is selected based on a position and a moving speed of the moving map data receiving device. A computer-readable recording medium on which the program is recorded. 57. The map data transmitting method, wherein the map data transmitting method is a map data transmitting method for transmitting map data to a map data receiving device having a display unit for displaying the map data. The map data transmitting method further comprises: A display scheduled time detecting step of detecting a scheduled display time, which is a time at which the data receiving device starts displaying the map data on the display unit, wherein the transmission schedule setting step includes the display scheduled time detecting step 56. A computer-readable recording medium recording a program for causing a computer to execute the map data transmission method according to claim 55, wherein the transmission schedule is set based on the scheduled display time detected by the computer. 58. The map data transmitting method further includes a transmission order priority setting step of setting a priority of a transmission order of the map data, wherein the transmission schedule setting step includes a step of: 58. The map data transmission method according to claim 57, wherein the transmission schedule is set based on the detected scheduled display time and the transmission order priority set in the transmission order priority setting step. A computer-readable recording medium on which a program for causing a computer to record is recorded. 59. The transmission schedule setting step, wherein the map data is not normally received by the map data receiving device when the map data receiving device does not normally receive the map data. And a retransmission assurance data group that ensures that the map data is always retransmitted to the map data receiving device, and the map data receiving device does not normally receive the map data when the map data receiving device does not normally receive the map data. A program for causing a computer to execute the map data transmission method according to claim 55, wherein the map data is divided into a retransmission non-guaranteed data group that does not guarantee retransmission to the map data receiving device. Computer readable recording medium. 60. The map data transmitting method further includes a transmission deadline detecting step of detecting a transmission deadline for transmitting the map data to the map data receiving device, wherein the transmission schedule setting step comprises: The transmission schedule is set based on the transmission time limit detected in the detection step.
A computer-readable recording medium on which a program for causing a computer to execute the map data transmission method according to 5 is recorded. 61. The map data transmission method, further comprising: a transmission processing completion time detecting step of detecting a transmission processing completion time when the map data transmission processing is to be completed; and transmitting the map data. A transmission processing end time detection step of detecting a transmission processing end time for ending the processing, wherein the transmission schedule setting step includes the transmission processing completion time detected by the transmission processing completion time detection step and the transmission processing completion time. The transmission schedule is set based on a comparison between the transmission process completion timing and the transmission process completion timing detected in the processing termination timing detection step, and the transmission process completion timing is set. Computer-readable recording a program for causing a computer to execute the map data transmission method described in 1. Recording medium. 62. The map data transmitting method according to claim 55, wherein the packet transmitting step transmits the data delivery packet without establishing a connection with the map data receiving device. A computer-readable recording medium on which a program to be executed by a computer is recorded. 63. The packet generation step, wherein a sequence number indicating a transmission order of the data delivery packet is added to the data delivery packet, and the packet generation step comprises: A retransmission guarantee sequence number assigned to a retransmission guarantee packet that guarantees that the data delivery packet that was not normally received by the map data receiving device when not received is always retransmitted to the map data receiving device; If the map data receiving device does not normally receive the data delivery packet, the retransmission non-guaranteed does not guarantee that the data delivery packet that has not been normally received by the map data receiving device will be retransmitted to the map data receiving device. The retransmission non-guaranteed sequence number given to the packet and the map data A computer-readable recording medium storing a program for executing the map data transmission method according to the computer to claim 55, wherein the generating a sequence number notification packet to notify the data receiving apparatus. 64. A map data transmission method for transmitting a data delivery packet storing map data to a map data receiving device, and a map data relay method for relaying the transmission of the data delivery packet. A computer-readable medium storing a program to be executed by a computer, wherein the map data transmission method includes: setting a transmission reliability priority of the map data transmission reliability to the map data; And a composite packet generating step of generating a composite data delivery packet that stores a plurality of map data in which the transmission reliability priorities different by the transmission reliability priority setting step are stored; The relay method includes a packet discarding step of discarding the data delivery packet. The packet discarding step is characterized in that, among the plurality of map data stored in the composite data delivery packet, map data set to have a lower transmission reliability priority than other map data is preferentially discarded. And a computer-readable medium storing a program for causing a computer to execute the map data transmission and relay method. 65. The composite packet generating step, wherein the map data set with the higher transmission reliability priority is stored at the beginning of the composite data delivery packet, and the transmission reliability priority is set lower. Storing the map data at the end of the composite data delivery packet, wherein the packet discarding step of the map data relay method includes the step of: The computer-readable medium storing a program for causing a computer to execute the map data transmission and relay method according to claim 64, wherein the map data is preferentially discarded from the map data stored at the tail. 66. The map data transmitting device of the map data transmitting method, wherein the map data transmitting device is a map data transmitting device for transmitting map data to a moving map data receiving device which is a moving object. A moving state information receiving unit that receives moving state information, which is information relating to movement of the moving map data receiving apparatus, from the moving map data receiving apparatus; and the display scheduled time detecting unit is received by the moving state information receiving unit. 2. The map data transmitting apparatus according to claim 1, wherein a scheduled display time is detected based on the moving state information. 67. The transmission schedule setting unit, wherein the transmission schedule setting unit sets the transmission schedule based on the scheduled display time detected by the scheduled display time detection unit and the transmission order priority set by the transmission order priority setting unit. 3. The map data transmitting apparatus according to claim 2, wherein the setting of the transmission schedule based on the transmission order priority set by the transmission order priority setting unit is dynamically switched. 68. The map data transmitting device, wherein the map data transmitting device is a map data transmitting device that transmits the map data to a map data receiving device having a display unit that displays the map data. A display unit pixel number detection unit that detects the number of unit pixels constituting the display unit of the map data receiving device; and the display unit based on the number of unit pixels of the display unit detected by the display unit pixel number detection unit. A display density detection unit that detects a display density that is a data amount per unit pixel of the map data to be displayed, wherein the transmission order priority setting unit includes the display density detected by the display density detection unit. The map data transmission device according to claim 2, wherein the transmission order of the map data is set based on the following. 69. The map data transmitting device, wherein the map data transmitting device is a map data transmitting device for transmitting the map data to a map data receiving device having a display unit for displaying the map data, wherein the map data transmitting device further comprises: A display unit pixel number detection unit that detects the number of unit pixels constituting the display unit of the map data receiving device; and the display unit based on the number of unit pixels of the display unit detected by the display unit pixel number detection unit. A display density detection unit that detects a display density that is a data amount of the map data to be displayed per unit pixel; and the display unit based on a display density per unit pixel of the display unit detected by the display density detection unit. An allocation unit pixel number detection unit that detects the number of unit pixels allocated to the map data displayed on the map data, the map data transmitted by the map data transmission device, A required unit pixel number detecting unit for detecting the unit pixel number necessary for displaying the map data on the display unit, wherein the transmission order priority setting unit includes the allocated unit pixel number detecting unit. 3. A priority setting for setting the transmission order of the map data based on the number of allocated unit pixels detected by the method and the required number of unit pixels detected by the required unit pixel number detecting unit. Or the map data transmission device according to 9. 70. The display density detection unit, wherein the display unit is divided for each part where the display density is approximated, and the display data per unit pixel of the map data displayed in the divided part of the display unit. An average display density detection unit that detects an average display density that is an amount for each of the divided parts of the display unit, wherein the transmission order priority setting unit is configured to detect the average display density detected by the average display density detection unit. 70. The transmission order of the map data is set based on the following.
2. The map data transmitting device according to 1. 71. A map data transmitting device for transmitting map data to a map data receiving device for receiving map data, a transmission map data selecting unit for selecting map data to be transmitted to the map data receiving device from the map data, A transmission schedule setting unit for setting a transmission schedule for transmitting the map data selected by the transmission map data selection unit. 72. The map data transmitting apparatus is a map data transmitting apparatus for transmitting map data to a moving map data receiving apparatus which is a moving body, and the transmission map data selecting unit is a current map data transmitting apparatus. 72. The map data to be transmitted to the moving map data receiving device is selected based on a position and a moving speed of the moving map data receiving device.
2. The map data transmitting device according to 1. 73. The transmission map data selection unit dynamically changes the timing of selecting the map data to be transmitted to the map data receiving device based on the data amount of the map data to be transmitted to the map data receiving device. 73. The map data transmitting device according to claim 71, wherein: