JP6066292B2 - Multifunction information terminal and communication method of mobile ad hoc network architecture - Google Patents

Description

The present invention relates to a mobile ad hoc network architecture and a communication method of the mobile ad hoc network architecture.

  In recent years, mobile terminals having a wireless communication function have been rapidly spread. Among them, mobile terminals equipped with Android (Android: registered trademark), which is a platform targeting mobile information terminals such as multi-function phones (smartphones) and tablet PCs, are prominent. Services are being developed. Against this background, the present inventors have developed a child watching system configured by a mobile ad hoc network (hereinafter referred to as MANET) using a wireless communication function installed in an Android terminal (Patent Document 1).

In the detection of Bluetooth (registered trademark) in Android, the following collision may occur. That is, there is a problem that the terminal that is performing the detection cannot be detected, and the connection to the terminal that is performing the detection fails. In order to efficiently configure Bluetooth MANET, it is necessary to avoid these collisions. Also, since the terminal moves in MANET, it is necessary to periodically detect and connect to communicate. In order to solve such a collision problem, the present inventors have proposed in Patent Document 1 a collision avoidance method in which each terminal autonomously estimates the status of an adjacent terminal.

On the other hand, MANET has the property that each terminal moves and autonomously forms a network. Therefore, in order to ensure this property, Bluetooth MANET, which applies Bluetooth to MANET, requires a technique for performing these processes periodically and confirming the presence of adjacent terminals (Non-patent Document 1).

Japanese Patent Application No. 2012-47444

Yuki Morii, Yuichiro Mori, Koji Takeda, Hideharu Kojima, Yoshiaki Kakuda, “Examination of collision avoidance method suitable for Bluetooth MANET implemented with AndroidAPI,” IEICE 14th Network Software Research Group, pp.7 -11, 2011.

In the MANET, Bluetooth MANET is used as a common wireless communication function in MANET, and the function is hierarchized and managed, thereby providing the Bluetooth MANET that is a common function as a service base. If a basic function is constructed, it is only necessary to select a higher-level service, so that efficient development can be performed. Furthermore, the present invention provides a hierarchical structure. That is, by preparing a plurality of hierarchies for one application, various functions can be exchanged for each layer. And they are designed specifically for building MANETs. For example, the MANET routing protocol can be exchanged.

The present invention is intended to efficiently develop a plurality of systems in consideration of these common points, and provides a network architecture based on Bluetooth MANET that satisfies this.

The multifunction information terminal according to the first aspect of the present invention provides:
Are services implementation utilizing configured mobile ad-hoc network function group in the lower layer, molding the data to be used for communication with the other terminal to the packet, and an application layer that sends to the lower layer,
A routing layer that is a lower layer of the application layer, and determines which terminal on the mobile ad hoc network the packet received from the upper layer and the lower layer is transferred to;
A lower layer of the routing layer, the include detection and connection process of the terminal, the Bluetooth communication is connection-oriented, is function implementation to apply to the mobile ad-hoc network the movement of the terminal is accompanied Rutotomoni, Bluetooth respect of the collision to be avoided that may occur in the detection, implements the collision avoidance means, and molding the information of the connection target terminal to the packet, comprising: a device layer that sends to the upper layer, and
Packets sent and received between layers are generated in a common data format.
It has a mobile ad hoc network architecture.

In the present invention, the routing layer includes autonomous distributed clustering means for grouping the terminals accompanying movement.

According to the present invention, the routing layer includes delay / disconnection-tolerant network means for maintaining reliability of environmental communication in which the network environment is sparse.

The communication method of the mobile ad hoc network architecture according to the second aspect of the present invention is:
A communication method of a mobile ad hoc network architecture using a Bluetooth communication function installed in a multi-function information terminal,
The mobile ad hoc network architecture is
Are services implementation utilizing configured mobile ad-hoc network function group in the lower layer, molding the data to be used for communication with the other terminal to the packet, and an application layer that sends to the lower layer,
A routing layer that is a lower layer of the application layer, and determines which terminal on the mobile ad hoc network the packet received from the upper layer and the lower layer is transferred to;
A lower layer of the routing layer includes a detection and connection process of the terminal, the Bluetooth communication is connection-oriented, functions to apply is mounted on a mobile ad-hoc network with the mobile terminal Rutotomoni, Bluetooth detection in contrast collision to be avoided that may occur, it is mounted collision avoidance means, and molding the information of the connection target terminal to the packet, and a device layer that sends to the upper layer Rutotomoni,
Generate packets sent and received between layers in a common data format ,
A step in which one multifunction information terminal detects another multifunction information terminal within a communication range between the multifunction information terminals;
The one multi-function information terminal makes a connection to the detected other multi-function information terminal;
And the other multi-function information terminal includes a step of accepting connection of the one multi-function information terminal.

In the communication method according to the present invention, the routing layer includes autonomous distributed clustering means for grouping the terminals accompanying movement.

Furthermore, the present invention is the communication method, wherein the routing layer includes a delay / disconnection-tolerant network means for maintaining the reliability of environmental communication in which the network environment is sparse.

According to the present invention, the tree-structured MANET construction method realized by Android's Bluetooth API can be applied to a system using short-distance communication, and each terminal periodically performs connection processing, thereby dynamically dividing the n-ary tree. A tree structure can be constructed.

Further, according to the present invention, in the hierarchical structure, elements can be easily exchanged in each layer, so that reusability is improved. Therefore, even if the protocol handled in the routing layer is changed, it can be implemented without changing the upper and lower layers. In addition, it is easy to cope with tests and error detection for each function, and is excellent in maintainability. That is, debug processing such as processing time measurement can be performed independently for each layer.

If there are few participants at the event venue or if the connection declines due to the collision characteristics of Bluetooth MANET, the network environment will be sparse. When the DTN means is built in the routing layer, each Android device moves to the surrounding Android device that can transfer it and evaluates it even if there is no Android device that can transfer the evaluation information to the surroundings. Information can be propagated in the network.

It is a figure which shows the connection procedure of Bluetooth. It is a flowchart which shows the flow until a terminal connects. It is a topology diagram of a tree structure. It is a graph which shows the hop number-RTT relationship of each terminal. It is a block diagram which shows the architecture of a hierarchical structure. It is a block diagram which shows the mounting structure of an architecture. It is the schematic for demonstrating a child watching system. It is the schematic for demonstrating the information communication service in event venues, such as an exposition. It is a figure for demonstrating Epidemic Routing. It is a figure for demonstrating the data transfer using Summary Vector. It is a graph which shows the relationship between the time concerning detection, and the number of detection terminals. It is a graph which shows the relationship of the throughput of Bluetooth communication-the number of simultaneous transmissions. It is a graph which shows the processing time for every hierarchy at the time of reception.

In the embodiment of the present invention, Bluetooth MANET using Bluetooth communication will be described. Class 2 Bluetooth has a lower radio wave output than general wireless LAN such as IEEE802.11b / g, and is suitable for MANET models using portable terminals. Bluetooth is also relatively resistant to radio wave interference due to the characteristics of the spread spectrum method used.

Since Bluetooth is connection-oriented communication, the procedure (steps S1 to S3) shown in FIG. 1 is necessary to communicate with an adjacent terminal. In the figure, A and B indicate terminals. Detection and connection of terminal A can be performed at any timing of the user.
S1 detection: Terminal A detects terminal B within the communication range.
S2 connection: Terminal A connects to detected terminal B.
S3 Acceptance: Terminal B accepts connection of adjacent terminal A.
Since MANET has the property that each terminal moves and autonomously configures the network, Bluetooth MANET needs to perform these processes periodically to confirm the existence of neighboring terminals in order to ensure this.

In this embodiment, Class 2 is used for wireless communication of the network architecture.
Bluetooth is used. This is IEEE802.11b / g
This is because the radio wave output is small compared to a general wireless LAN, and it is suitable for the MANET model using the assumed portable terminal. In addition, due to the above specifications and the features of the spread spectrum method used in Bluetooth, it is relatively resistant to radio interference.

Construction method The following describes the API and algorithm used specifically for the construction method of the tree structure MANET using the Bluetooth API. We will also consider how to construct a similar network structure and describe an actual application example where the tree structure is effective.

Bluetooth API
Among the Android SDK distributed by Android Developers, there are the methods shown in Table 1 (Basic Bluetooth API) as the basic API for performing the connection procedure described above. The method is implemented using these methods.

An algorithm for constructing an algorithm tree structure is described. FIG. 2 shows a flowchart until the terminals are connected to each other, and the procedure will be described in the order of steps (S11 to S16).
S11. Each terminal first determines a detection time and a detection cycle at the time of activation. With Android Bluetooth, there are challenges related to detection collisions. A method of efficiently interconnecting by dynamically changing the detection time and the detection cycle is adopted, and the value by this method is determined by this processing.
S12. Start detection.
S13. Detect the terminal.
S14. When a terminal is detected, it is added to the detected list.
S15. If no terminal is detected, the detection ends.
S16. When the detection is completed, a connection request is issued with reference to the detected list.

In this method, a request is issued to an unconnected terminal at that time. Therefore, the link structure becomes an n-ary tree, and a tree structure can be constructed. Here, a connection request is made to all the terminals that have been detected and not yet connected. Therefore, an attempt is made to establish an n-ary tree by trying to connect without any upper limit within the range of the number of terminals that can be detected. Since there is an upper limit on the number of simultaneous connections in Bluetooth, it is possible to reduce useless connections by constructing an n-ary tree in consideration of the surrounding tree structure. As a specific method, a limited number of connection requests or intentional connection disconnection can be performed by referring to its own connected terminal list, a list of connections managed by neighboring terminals, and a detected list.

Features of the construction method Among the network structures, a network construction method with a tree structure will be described. In addition, MANET construction with a ring structure can be considered as a specific example. In the ring structure, data transfer is performed so as to go around the ring. As described above, there is an upper limit on the number of simultaneous connections that can be made in Bluetooth, and countermeasures are necessary. Also, a network structure that takes only a pure ring structure is hard to say as MANET. Considering this, the most typical tree structure in MANET is constructed.

Application Example By constructing the tree structure MANET by the above-described method, it is possible to configure a network with a plurality of unspecified terminals accompanying movement. By applying this, it is possible to realize an information propagation system in event venues such as various expositions and a child watching system useful for safety information. In the former system, the evaluation information of the exhibit by the event participant is propagated to the surroundings, and in the latter system, the information on the person to be watched can be transferred to the guardian.

Operational Experiments We will describe the behavioral and characteristics of the results of the operational experiments using the Android terminal real machine in the tree structure MANET constructed by the method described above.

FIG. 3 shows the topology of the experiment contents and the environment tree structure. The terminal S is a transmission source terminal, and data is transferred to all terminals A, B, C, D, and E by flooding. The terminals A to E that have received the data return an acknowledgment to the transmission source. In the experimental example, the delay confirmation response time (RTT: Round Trip Time) of each terminal A to E was measured. The data size for measurement was set to about 50 bytes, and execution was performed 7 times, and the average value was obtained as a result. In addition, multiple actual devices with different manufacturers and Android OS versions were mixed and executed.

Experimental Results The above results are shown in FIG. In the figure, the horizontal axis represents the number of hops, and the vertical axis represents the measured RTT value. IDs A, B, C, and D attached to the top of each element indicate terminal IDs A, B, C, and D in FIG. The result of terminal E is omitted because it is handled in the same manner as terminal A in view of the topology.

As shown in FIG. 4, the RTT increases in proportion to the number of hops. Its value is on the order of milliseconds, and it can be seen that it is extremely short. Since the data is transferred without any problem in this way, it can be seen that the MANET function is operating normally in the tree structure topology. There is also a slight difference in the values between the same hop numbers. This is probably because a packet is transmitted to a plurality of terminals at the same time on the application of the transmitting terminal, but there is a competition in Bluetooth communication and a slight time difference is created.

In this experimental example, the MANET construction method of the tree structure realized by Android's Bluetooth API was described. By adopting a tree structure that is a characteristic network form of MANET, it can be applied to a system using proximity communication, and each terminal periodically performs connection processing to dynamically construct an n-ary tree tree structure. be able to.

Network architecture Next, the network architecture based on Bluetooth MANET is described.

Functions of each layer The network architecture according to the present invention is composed of an application layer, a routing layer, and a device layer, and each layer has the following functions.

Application layer: Service provision Implement service contents using MANET function group composed of lower layers. Since this embodiment uses an Android terminal, the user interface is implemented. Data used for communication with other terminals is first formed into packets in this layer and transmitted to the lower layer.

Routing layer: MANET routing Determines how the packet received from the upper and lower layers is forwarded to which terminal. Specifically, autonomous distributed clustering that efficiently groups terminals with movement, delay and disconnection tolerance network (DTN: Delay and Disruption Tolerant Network) that demonstrates communication reliability in a sparse network environment, Other MANET routing protocols can be implemented.

Device layer: Bluetooth MANET
Implements a function to apply connection-oriented Bluetooth communication to MANET with terminal movement, including terminal detection and connection processing. It is possible to implement collision avoidance means for collisions that should be avoided that may occur in Bluetooth detection on Android. In this way, hierarchies are designed and functions are implemented independently. In particular, the routing layer is specialized to implement the MANET routing protocol, and the device layer can implement Bluetooth MANET, enabling efficient design of MANET-based systems.

Hierarchical Structure Hereinafter, a specific hierarchical structure of the architecture will be described with reference to FIG. Each of the three layers, that is, an application layer (Application Layer) 1, a routing layer (Routing Layer) 2, and a device layer (Device Layer) 3, each inherits an abstract layer having a common communication function. In the abstract layer, a receive buffer 4 and a send buffer 5 are prepared, and packets are inserted into these when transmitting and receiving. In addition, as a packet processing function, a reception process 6 and a transmission process 7 are prepared as abstract methods, and are responsible for all processes during transmission and reception. For example, in the case of the routing layer 2, when the received packet is not addressed to itself, processing such as referring to its own routing table and transmitting to the next transfer destination is described in the reception process. Packet header addition and removal processing at each layer is also performed within this process.

Each layer holds an instance of a lower layer, and calls a packet transmission / reception process of another layer based on this. Further, the transmission / reception buffer is monitored by the thread of each layer, and the thread waits until a packet is inserted into the buffer. In the device layer 3, which is the lowest layer, transmission and reception are performed through the Bluetooth 8 API provided by Android.

Communication between layers Communication between layers is performed using a common data format created uniquely. This is prepared as an abstract packet, and all packets in all layers are made the same abstract packet. Therefore, it is easy to add a packet. In addition, the packet element storage method is designed not to depend on the type or number of data, and any type and any number can be flexibly stored, and it is resistant to additional changes of elements.

Mounting Method An image of the mounting method is shown in FIG. As shown in the figure, the three layers, Application Layer 1, Routing Layer 2 and Device Layer 3 inherit a common abstract layer 9. When actually implementing in a system, the concrete layer finally utilized can be produced | generated by inheriting these layers further. Furthermore, if each layer is set and handled as a protocol stack 10, the entire system can be activated. Further, since the network architecture is premised on mounting on a terminal, the mounting language is Java (registered trademark).

Implementation Example Two of the watching system developed using the network architecture according to the embodiment and the information transmission system at the event venue such as an exposition (Hiroshima Confectionary Expo 2013 service system) will be described.

Child watch system The child watch system is a MANET-based watch system that has been improved based on the knowledge and experience gained in the Hiroshima City Child Watch System Model Project. The purpose of the system is to efficiently and safely collect information for watching children on the school road, and the image is shown in FIG.

The system consists of an Android terminal 11
It consists of a mesh network composed of MANET, a tag 12 attached to a utility pole, and a server 13. In order to efficiently manage the terminals 11 that take various forms of movement, autonomous distributed clustering that autonomously forms groups is applied. The cluster information collected between the terminals 11 is transmitted to the tag 12 as watching information and transferred to the server 13 through the mesh network. The server 13 is connected to the Internet, and a guardian can check watching information via the Internet. This network architecture is applied to an application mounted on the terminal 11 in the system. The functions of each layer in the network architecture applied to the child watching system are shown below.

Application layer: Tag-terminal communication, various UI
A communication management function between the tag 12 and the Android terminal 11 and a user interface for various settings and information browsing are implemented. Cluster information collected in the lower layer is used as data, and is periodically transmitted to the tag 12.

Routing layer: Autonomous distributed clustering Each Android terminal 11 is assumed to take various forms of movement. Therefore, in order to cope with this efficiently, autonomous distributed clustering capable of autonomously forming a group is implemented.

Device layer: Bluetooth MANET
The device layer implements Bluetooth MANET as a common wireless communication function. Further, the collision avoidance means described above is applied.

Autonomous distributed clustering clustering is a technique of managing a hierarchy by dividing a network into sub-networks, and the sub-networks are called clusters. Multiple clusters do not overlap each other, and each terminal can belong to only one cluster.
In autonomous distributed clustering, each cluster is composed of one cluster head and a plurality of cluster members. The cluster head exchanges information to construct a tree structure rooted in itself. The cluster head manages the size of the cluster using the lower limit value and the upper limit value of the number of cluster members.

Hiroshima Confectionary Expo 2013 Service System Inventors have developed a propagation and collection system for confectionery evaluation information using the Android terminal and Bluetooth MANET for the “Hiroshima Confectionery Expo 2013” exhibition. The image of “Hiroshima Confectionery Expo 2013 Service System” is shown in FIG.

At the event venue, a participant (visitor) 14 tastes a variety of sweets at each store 15 and moves. At that time, it is expected to evaluate “delicious” and “beautiful”. This system automatically propagates and collects this as evaluation information by MANET using the terminal 11. The terminal 11 has a function for the participant 13 to write evaluation information, a function for propagating evaluation information via MANET, a function for collecting evaluation information, and a function for displaying evaluation information. Thereby, evaluation information can be given in real time to a participant who has the terminal 11, and the service can be enjoyed in a sense of a game in the venue.

On the other hand, if the number of participants 13 is small or the connectivity of Bluetooth MANET is expected to deteriorate. In such a situation, the network environment is sparse, so the delay / disconnection tolerance network DTN is applied. Specifically, storage and transport data transfer (Epidemic Routing) is performed. That is, as shown in FIG. 8, even if there is no Android terminal that can transfer the evaluation information in the surrounding area like the central Android mobile terminal 11, each Android terminal is transferred to the surrounding Android terminal that can be transferred after moving. Thus, the evaluation information can be propagated in the network. The received evaluation information is output to the screen of the Android terminal, and the participant can view the evaluation information in real time. Network architecture applies to this Android application.

The functions of each layer in the network architecture are shown below.
Application layer: design, various UI
Implement application screen transition, user interface, and data input / output functions. Participants create evaluation information by inputting various evaluation items. The created evaluation information is formed into a packet as data and transmitted to the lower layer. When the evaluation information is received, it is output on the screen so that the participant can easily see it.

Routing layer: DTN (Epidemic Routing)
Implement a storage and transport data transfer method. The routing layer stores data received from the upper and lower layers. When there is a change in the connection status due to movement or Bluetooth MANET, if there is an Android device that can communicate and does not have the data held by itself, the data is transferred. FIG. 9 shows an operation example of Epidemic Routing. A terminal is indicated by a circle in the figure. The mobile terminal A that has received the information from the terminal S stores the data in itself. The terminals that can communicate with the terminal A vary with time. At this time, by taking the difference between the data information held by the adjacent terminal, the data not held by each other is transferred. By repeating the same operation, the data of the terminal S can be propagated to the network.

Device layer: Bluetooth MANET
The device layer implements Bluetooth MANET as a common wireless communication function. Since this service uses a common Bluetooth MANET function, it is the same as that of the child monitoring system described above. Thus, it has the feature that the upper layer can be selected even though the base is the same.

DTN: Delay / cut-tolerant network In this system, Epidemic Routing, one of the DTN technologies, is implemented. Epidemic Routing stores data in the terminal. In this system, data is accumulated in the following cases.
• Information was generated by the user.
・ New data has been received.
When data is received, a case where the same data is already accumulated from another terminal can be considered. In this case, identification is performed using the ID and time stamp of the data generation terminal to avoid duplication. In the current implementation, the data storage time is 30 minutes from the generation time. However, since the amount of data stored in the terminal is finite, this parameter is important in actual operation. Therefore, it is necessary to consider from the viewpoint of time, number, capacity, and the like.

Exchange of stored data information and data transfer In order to transfer stored data to adjacent terminals, a stored data list called SV (Summary Vector) held in each terminal is used. Each terminal can acquire data that it does not accumulate by periodically exchanging SVs. SV is a list composed only of data identifiers, and does not include the data itself. For this reason, overhead can be reduced compared to transmission of all stored data.

Data transfer using SV in this system will be described with reference to FIG. In the figure, it is assumed that each terminal A, S, B can communicate with each other. First, the terminal S broadcasts an ^{SVS that} is an SV held by the terminal S. The terminal A receiving it generates a difference SV (˜SVS · SVA) from the ^SVA held by itself. Based on this, Data (~ SVS · SVA), which is a difference data list, is unicast to the terminal S. A similar process is performed on terminal B. By performing such processing periodically at each terminal, data that could not be received immediately can be received. In the current implementation, SV is transmitted at a transmission interval of 30 seconds. Since there is a trade-off relationship between information dissemination speed and overhead, it is necessary to consider the optimal transmission interval.

Implementation and operation experiment The characteristics and system operation of the mobile ad hoc network architecture according to the present invention are confirmed.

All of the experimental environments were Android devices. Two types of terminals were prepared and experimented by mixing them appropriately. The specifications are shown in Table 2. The experiment was conducted in an environment where radio waves in the same frequency band as Bluetooth (IEEE802.11g / n in the 2.4 GHz band, etc.) coexist.

Experiment on Bluetooth Communication Bluetooth communication was used as the communication means of the network architecture according to the present invention. In constructing Bluetooth MANET, we will show how the connection with the neighboring terminal is related by the actual machine experiment. The following describes two experiments for detecting a plurality of adjacent terminals and measuring throughput in data transfer.

Six test terminals for detection are used, and one is used as a detection terminal. The other 5 devices are detected terminals. The detected terminal does not perform detection processing and is in a state where it can always be detected. In one detection process, the relationship between the time transition and the number of detected terminals was examined. The experimental results are shown in FIG. In the figure, the horizontal axis represents time, and the vertical axis represents the total number of terminals discovered by one detection. The experiment was performed 100 times, and the average value was used as the experimental result. As shown in the figure, detection starts immediately after the start of detection, and the number of detected terminals increases in proportion to time. It was found that almost all terminals can be detected by detecting for about 6 seconds. The result obtained by this experiment is used to determine the detection period and detection time. Also, the above-described collision avoidance means can be applied.

Throughput measurement of Bluetooth communication
Considering the premise of building a MANET, we measured the throughput for multiple simultaneous communications. The data size for measurement was about 30 KB, 10 trials were performed, and the average value was the result. The experimental results are shown in FIG. In the figure, the horizontal axis represents the number of simultaneous transmissions (concurrency), and the vertical axis represents the throughput. When the number of simultaneous transmissions is 1, there is a throughput of about 1 Mbps, and it can be seen that communication can be performed relatively fast even when viewed from the standard theoretical value of 3 Mbps of Bluetooth 2.0 + EDR. In addition, positive and negative errors of about 200 Kbps are recognized. This is considered to be due to the influence of other mixed radio waves as described in the experimental environment, resulting in numerical errors due to the transfer timing. In contrast, when the number of simultaneous transmissions is 2 or 3, the throughput is drastically decreased. This is considered that the contention of the band has occurred because the terminal transmits at the same frequency band at the same time. For this reason, when data is simultaneously transferred to a plurality of terminals, it can be said that it is disadvantageous if the data size is large.

Experiments on communication between layers The experiments on communication between layers provided by the network architecture are described. The protocol implemented in each layer is completely independent of the other layers. Therefore, with this architecture, the processing time of each pure protocol can be easily measured. Specifically, taking the “Hiroshima Confectionary Expo Service System” as an example, we measured the time required for reception processing at each level and confirmed the effect. In the experiment, arbitrary word-of-mouth information was transmitted from a certain terminal and received. Note that word-of-mouth information was measured when there was no photo data (data size is large or small) to show the difference in reception processing time. The above experiment was performed 10 times and the average value was taken. The experimental results are shown in FIG. In the figure, the horizontal axis represents each layer, that is, the layer that performs GUI operation in the case of this experiment, the routing layer to which DTN is applied, and the layer that implements Bluetooth MANET, and the vertical axis represents the processing time.

From FIG. 13, it can be seen that the processing time of the device layer is very short. In the current implementation, the device layer receives the entire data and then simply transfers it to the upper layer without performing any special processing. Transfer delay is not included in the figures. In other layers, it can be seen that word-of-mouth information with a photo with a large data size takes longer to process than when it is not. It can also be seen that the routing layer takes longer than the application layer. This is considered to be due to processing such as packet duplication and comparison with existing accumulated data at the time of reception. In this way, the application of the network architecture makes it possible to consider each layer separately, which is excellent in maintainability.

The present invention is a system that promptly acquires information for watching a group in which a plurality of people move together, such as the child watching system described above, and an exhibition such as the Hiroshima Confectionary Expo 2013 service system described above. It can be used in a system that gradually provides information for an event to people who are not acquainted with each other moving in the event venue.

S, A, B, C, D, 11 Terminal 1 Application layer 2 Routing layer 3 Device layer 4 Receive buffer
5 Transmission buffer 6 Reception process means 7 Transmission process means 8 Bluetooth
9 Abstract layer 10 Protocol stack 12 Tag 13 Server 14 Participant 15 Store

Claims (6)

Been implemented services using configured mobile ad-hoc network function group in subordinate layer, molding the data to be used for communication with the other terminal to the packet, and an application layer that sends to the lower layer,
A routing layer that is a lower layer of the application layer, and determines which terminal on the mobile ad hoc network the packet received from the upper layer and the lower layer is transferred to;
A lower layer of the routing layer includes a detection and connection process of the terminal, the Bluetooth communication is connection-oriented, functions to be applied to mobile ad-hoc network the movement of the terminal involves is mounted Rutotomoni against collision should be avoided that may occur in the Bluetooth detection, it implements the collision avoidance means, and molding the information of the connection target terminal to the packet, and the device layer that sends to the upper layer, Have
Packets sent and received between layers are generated in a common data format.
With mobile ad hoc network architecture,
Multi-function information terminal characterized by that . The routing layer is
The multifunction information terminal according to claim 1, further comprising autonomous distributed clustering means for grouping the terminals with movement . The routing layer is
The multi-function information terminal according to claim 1 or 2, further comprising delay / disconnection-tolerant network means for maintaining reliability of environmental communication in which the network environment is dense . A communication method of a mobile ad hoc network architecture using a Bluetooth communication function installed in a multi-function information terminal,
The mobile ad hoc network architecture is
Are services implementation utilizing configured mobile ad-hoc network function group in the lower layer, molding the data to be used for communication with the other terminal to the packet, and an application layer that sends to the lower layer,
A routing layer that is a lower layer of the application layer, and determines which terminal on the mobile ad hoc network the packet received from the upper layer and the lower layer is transferred to;
A lower layer of the routing layer includes a detection and connection process of the terminal, the Bluetooth communication is connection-oriented, functions to apply is mounted on a mobile ad-hoc network with the mobile terminal Rutotomoni, Bluetooth detection in contrast collision to be avoided that may occur, it is mounted collision avoidance means, and molding the information of the connection target terminal to the packet, and a device layer that sends to the upper layer Rutotomoni,
Generate packets sent and received between layers in a common data format ,
A step in which one multifunction information terminal detects another multifunction information terminal within a communication range between the multifunction information terminals;
The one multi-function information terminal makes a connection to the detected other multi-function information terminal;
And a communication method of a mobile ad hoc network architecture, characterized in that the other multi-function information terminal includes a step of accepting connection of the one multi-function information terminal . The routing layer is
The communication method of the mobile ad hoc network architecture according to claim 4, further comprising autonomous distributed clustering means for grouping the terminals with movement . The routing layer is
The communication method of the mobile ad hoc network architecture according to claim 4 or 5, further comprising delay / disconnection-tolerant network means for maintaining the reliability of environment communication in which the network environment is sparse .

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