Mobile communication system and method

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a mobile communication system and a method, and is suitable for application to, for example, when performing communication corresponding to MIP (Mobile IP) specified in RFC2002, which is a document issued by the IETF (Internet Engineering Task Force). Is.

【0002】

[Conventional technology]

The IETF has developed a protocol called MIP so that mobile nodes (MN: mobiles) can communicate via a router connected at the destination with a fixed IP address peculiar to mobile nodes. This is a protocol for maintaining communication at the IP (Internet Protocol) layer even if the link is re-linked at the destination. The process required to reconnect the link at the destination and maintain communication is called the handover process.

【0003】

In the handover process, various information (that is, context) necessary for the continuation of communication is passed, and it takes time to pass the information. Therefore, the MN actually moves to the adjacent wireless zone (cell). If the transfer is performed after the movement, the communication will be temporarily stagnant during the handover process.

【0004】

In order to solve this problem, the same IETF is developing a protocol to smoothly execute handover processing on MIP at the same time as the MIP protocol. The CT (Context Transfer) method, which is one of these methods, will be described with reference to FIG.

【0005】

According to the CT method, the AR (access router) 2002 to which the MN2005 is connected by a wireless link, etc., is before the MN2005 moves from the wireless zone Z1 it covers to the adjacent wireless zones Z2, Z3, etc. It transmits the above-mentioned context related to communication with MN2005 to AR2003A, 2003B, etc. that cover the adjacent radio zones Z2, Z3, etc. As a result, the AR2003A and 2003B to be connected next can perform the handover process in advance, so that when the MN2005 relinks with the next AR (one of 2003A, 2003B, etc.), it communicates. Will not stagnate.

【0006】

In fact, when the MN2005 moved to the wireless zone (for example, Z2), the initialization process for the compression protocol described above, the initialization process for the tunneling protocol with HA, the QоS reservation of the communication path, and the re-authentication were already performed. This is because securing an encrypted communication path is being executed, and it is possible to reduce packet loss, communication delay, etc. that may occur when reestablishing a session such as QoS reservation or compression protocol. is there.

【0007】

In FIG. 2, GW2001 is a gateway that accommodates AR1, AR2003A, 2003B, AR2004, etc. and connects to the network 2000.

【0008】

In addition, a method of introducing and configuring an access point (AP) has been proposed in order to reduce the interruption of connectivity due to the change of access destination with respect to the movement of MN. The AR is an IP layer device, but the AP is a device in a lower layer than the IP layer, and MN does not directly access the AR, but multiple APs are connected to the AR, and the MN is the most when moving. It communicates with AR via a nearby AP.

【0009】

Figure 6 shows an example of a network configuration with AP installed. The difference from Fig. 2 is that in Fig. 2, AR directly covered the radio zone (Z1, Z2, etc.), whereas in Fig. 6, AP directly covered the radio zone, and 1 or Only the point that multiple APs are accommodated in one AR. Although it is indirect because AP is inserted in the middle, the structure in which each AR accommodates MN has not changed even with the configuration shown in Fig. 6. Therefore, the above description of FIG. 2 applies almost exactly to FIG.

【0010】

However, when one AR accommodates multiple APs, the multiple small radio zones covered by the multiple APs are treated as a single large radio zone when viewed from the AR hierarchy. For example, for the AR6003, the large radio zone, which is a combination of the four small radio zones covered by AP6007A to 6007C and AP6008, will be treated as a single radio zone.

【0011】

It is natural that these small radio zones are different radio zones from the viewpoint of the AP hierarchy.

【0012】

In FIG. 15, for example, assuming that the radio zone covered by the AR6003 in FIG. 6 is a large area 15b, the area covered by the AP6007A to 6007C, 6008, etc. accommodated by the AR6003 is a small area inside the area ( 15f etc.). In Fig. 15, seven small radio zones are included in the large radio zone 15b, so according to Fig. 15, the AR6003 has seven APs (four of which are 6007A to 6007C and 6008) under it. It will be contained.

【0013】

In this case, the large radio zone 15a on FIG. 15 is covered by an AR other than the AR6003 (for example, AR6002 in FIG. 6), and the large radio zone 15c is covered by a third AR (for example, AR6004 in FIG. 6). Will cover. In addition, each AR will accommodate 7 APs under its control, corresponding to 7 small radio zones contained inside the radio zones 15A and 15c.

【0014】

In the example of FIG. 15, the MN2005 goes straight from the start point SP to the end point EP along the route RT1. This route RT1 exists geographically across all large radio zones 15a to 15c when viewed in the hierarchy of the large radio zone, but when viewed in the hierarchy of the small radio zone, it is above the small radio zone 15d to 15h. Although it exists, it does not exist on other small radio zones.

【0015】

Therefore, when the MN2005 moves along the route RT1, at the starting point SP, the MN2005 accesses the AR6002 and the network 6000 via, for example, the AP6006, and wireless communication is performed every time the small radio zone to which the MN2005 belongs changes with the movement. The AP that communicates is switched, and the AR that communicates (receives relay processing) is switched each time the large radio zone to which it belongs changes.

【0016】

Figure 4 shows the internal configuration of MN2005. In FIG. 4, the MN2005 includes a control unit 4001, a communication unit 4002, a MIP processing unit 4003, and an application processing unit 4004.

【0017】

Data packets and control packets used for communication are input and output via the communication unit 4002.

【0018】

The MIP processing unit 4003 is a part that performs the MIP processing by the control packet and the data packet passing processing, and the application processing unit 4004 processes the communication application, generates the data packet to be transmitted, and processes the received data packet. Is the part to do.

【0019】

The internal configuration of the AP is shown in FIG. The internal configurations of the APs shown in FIG. 6 (eg, 6007A and 6006) may all be the same.

【0020】

In FIG. 5, the AP includes a control unit 5001, a communication unit 5002, and a MIP processing unit 5003.

【0021】

The communication unit 5002 is a part that receives and processes data packets and control packets, passes them to the MIP processing unit 5003, receives the packets generated by the MIP processing unit 5003, and sends data to an appropriate link.

【0022】

Finally, FIG. 3 shows the internal configuration of the AR. The internal configuration of the AR in Fig. 6 that accommodates the AP under it and the AR in Fig. 2 that does not accommodate it are actually different in terms of the presence or absence of a wireless communication function for wireless communication with the MN, but are shown in Fig. 3. This difference is ignored at the level. Therefore, as far as the components shown in FIG. 3 are concerned, it can be said that the AR on FIG. 2 (for example, 2002) and the AR on FIG. 6 (for example, 6002) have the same internal configuration.

【0023】

In FIG. 3, the AR includes a control unit 3001, a communication unit 3002, a MIP processing unit 3003, and a next candidate AR determination unit 3004.

【0024】

The MIP processing unit 3003 processes the input data packet and control packet, but when the control unit 3001 determines that handover processing is necessary based on the control packet information and radio strength, the next candidate AR is determined. Unit 3004 determines a candidate AR to be the destination of the context transfer according to the CT method, and executes the context transfer to the candidate AR. Then, this context transfer enables smooth handover processing without stagnation of ongoing communication.

【0025】

[Problems to be Solved by the Invention]

However, as is clear from the radio zones Z1 to Z3 in Fig. 2 and Fig. 15, the radio zones are usually set geographically close to each other so as to overlap each other, so they are candidates. The number of AR is large. Considering that the movement speed of MN may be high, each AR that covers the radio zone (adjacent radio zone) directly adjacent to the radio zone of the AR currently communicating with MN, as well as each of these This is because it is necessary to transfer the context to each AR that covers the radio zone (indirect radio zone) adjacent to the AR.

【0026】

Focusing on the radio zone E0 assuming that the MN is located in the radio zone E0 located in the center of FIG. 20, the radio zones E1 to E6 are adjacent radio zones to the radio zone E0, and the radio zones E11 to E22 are. It is an indirect radio zone. Including the indirect radio zone, there are 19 radio zones in Fig. 20.

【0027】

When transferring context to many candidate ARs (for example, 18 candidate ARs out of these 19 radio zones excluding the radio zones that they cover), the ARs and networks that transfer the context will have an excessive processing load. Network load occurs.

【0028】

Although there is only one radio zone in which the MN actually moves, it can be said that the efficiency of context transfer is low when the context is transferred to such a large number of candidate ARs.

【0029】

It is conceivable to reduce the number of candidate ARs to reduce these loads, but if the number of candidate ARs is reduced unnecessarily, it is highly likely that the MN will move to the radio zone of the AR that is not transferring context. turn into. Due to the nature of context transfer, if the MN moves to the radio zone of the AR that does not transfer the context, naturally the handover process cannot be performed smoothly, and communication temporarily stagnates during the process time. For MN users, this stagnation is perceived as a break in communication, leading to poor communication quality and poor communication reliability.

【0030】

[Means for solving problems]

In order to solve such a problem, in the first invention, a mobile communication terminal that moves on a predetermined geographical area while continuing a predetermined communication, and a relay device network including a plurality of relay devices that relay the communication. At least a part of the plurality of relay devices included in the relay device network is a cover relay device having a wireless communication means for directly executing communication with the mobile communication terminal, and each cover relay device. In a mobile communication system in which the cover area covered by is configured to cover the geographical area, at least the cover relay device among the relay devices (1) guarantees the continuation of the communication by using predetermined context information. Context-corresponding means to be used, (2) a mobile route predicting means for predicting the moving route of the mobile communication terminal communicating by the wireless communication means by using a predetermined prediction process, and (3) the moving route predicting means. For the candidate cover relay device that selects the candidate cover relay device from the cover relay devices that may have the cover area on the movement path predicted by (4) and (4) the candidate cover relay device selected by the candidate cover relay device. It is characterized in that it includes a context information transfer means for transferring the context information.

【0031】

Further, in the second invention, at least one of a plurality of relay devices in which the mobile communication terminal moves on a predetermined geographical area while continuing a predetermined communication and relays the communication within the predetermined relay device network. The unit is a cover relay device having a wireless communication means for directly executing communication with the mobile communication terminal, and the cover area covered by each cover relay device is a mobile communication method covering the geographical area. Of the relay devices, at least in the cover relay device, (1) the context-supporting means guarantees the continuation of the communication using predetermined context information, and (2) the mobile communication terminal communicating by the wireless communication means. With respect to, the movement route is predicted by the movement route prediction means using a predetermined prediction process, and (3) from among the cover relay devices capable of having the cover area on the movement route predicted by the movement route prediction means. The candidate cover relay device selects the candidate cover relay device, and (4) the context transfer means transfers the context information to the candidate cover relay device selected by the candidate cover relay device.

【0032】

BEST MODE FOR CARRYING OUT THE INVENTION

(A) Embodiment Hereinafter, embodiments will be described by taking the case where the mobile communication system and method according to the present invention are applied to the mobile communication system using the MIP as an example.

【0033】

The handover process generally refers to a process of passing necessary information (context) at a mobile communication exchange or the like in order to continue the communication (session) when the MN crosses the wireless zone during communication. Therefore, the handover process is not a process peculiar to MIP, but is used in many mobile communications.

【0034】

However, in the handover process related to MIP, the transfer of the context is executed between routers (access routers (AR)) covering each geographically adjacent radio zone. The contents of the context include, for example, the processing of initialization for the compression protocol performed on the link communication such as wireless, and the initialization of the tunneling protocol with the home agent (HA) specified in the MIP. It is various information related to processing, QоS (quality of service) reservation of communication path, re-authentication, and securing of encrypted communication path.

【0035】

In addition, since the AR is basically a router that performs processing corresponding to the network layer of the OSI reference model, packets that are the protocol data unit of the network layer (here, IP) are also used for the transfer of the context between the ARs. Packet) will be used.

【0036】

A feature common to the first to fifth embodiments is that the destination of the MN is predicted and the context transfer is processed efficiently and effectively, and the effective use of network resources and the maintenance of communication quality are achieved. .. As a result, the range of context transfer can be appropriately expanded according to the movement speed of the MN, and the handover processing at the time of high-speed movement can be efficiently performed.

【0037】

(A-1) Configuration of First Embodiment The overall configuration example of the mobile communication system of the present embodiment may be the same as that of FIG. 2 described above. However, the internal configurations of MN and AR among the components shown in Fig. 2 are different from the conventional ones.

【0038】

Note that Fig. 2 shows a schematic configuration omitted in many respects, but in reality, AR has a function as a wireless base station for MN, so for example, frequency repetition of the small zone system of a car phone. It is natural that a large number of base stations, that is, ARs, are arranged corresponding to a pattern (12-cell repeating pattern) and the like. Therefore, if a part of the radio zone group covered by each of these a large number of ARs is extracted and illustrated, for example, the radio zone configuration as shown in FIG. 20 can be obtained. In FIG. 20, as described above, 19 radio zones E0 to E6 and E11 to E22 are arranged.

【0039】

Further, if necessary, an AR having a function as a radio base station may not be directly connected to the GW2001, but a relay router may be arranged between the AR and the GW2001. The relay router may intervene not only between AR and GW2001 but also between AR and AR.

【0040】

As long as it is a mobile communication system, it is normal that there are an unspecified number of independent MNs in the system, but in the following, the explanation will mainly focus on one MN (here, MN8000).

【0041】

Figure 1 shows an example of the internal configuration of the AR1000 of this embodiment that performs wireless communication with the MN8000. In this embodiment, AR cooperates with MN8000 to predict the destination of the MN8000.

【0042】

(A-1-1) AR internal configuration example In FIG. 1, the AR (access router) 1000 is close to the control unit 1001, the communication unit 1002, the MIP processing unit 1003, the next candidate AR determination unit 1004, the speed measurement unit 1005, the position detection unit 1006, and the like. It includes an AR position search unit 1007, a position data storage unit 1008, a movement prediction unit 1009, and a prediction pattern holding unit 1010.

【0043】

Of these, the communication unit 1002 is a part that inputs and outputs the data packet DP1 and the control packet CP1, and the MIP processing unit 1003 is a part that processes the input data packet DP1 and the control packet CP1 according to the MIP. A data packet is a packet containing user data for the MN8000 to communicate with other MNs or fixed communication terminals, and a control packet is a packet for performing control related to MIP. Is. In addition to these, the packets for which the communication unit 1002 performs input / output processing include a speed information notification packet VN1, a position information notification packet PN1, and a radio zone information-related packet ZN1 which will be described later.

【0044】

The packet CX1 for context transfer is also sent and received by the MIP processing unit 1003.

【0045】

Control unit 1001, pre SL and information control packet is determined portion whether it is necessary to such a handover process intensity of the radio to communicate between the MN8000. Generally, when the MN8000 is located near the center of one radio zone covered by the AR1000, it is determined that there is no need for handover processing because sufficient strength is obtained, and when it is located near the outer edge, sufficient strength is obtained. There is a high tendency to determine that handover processing is necessary because it cannot be obtained.

【0046】

The next candidate AR determination unit 1004 is a part that determines the AR that is the destination to transfer the context, but in the present embodiment, the destination of the context according to the prediction result information CN1 of the movement route of the MN8000 by the movement prediction unit 1009. Since the next candidate AR to be used is determined, the number of next candidate ARs is usually smaller than before.

【0047】

The movement prediction unit 1009 acquires various basic information from the speed measurement unit 1005, the position detection unit 1006, and the position data storage unit 1008, and executes a predetermined prediction process based on these basic information to move the MN8000. This is the part that predicts the route. In this prediction process, it is sufficient if the wireless zone to which the MN8000 is moved can be narrowed down.

【0048】

The speed measurement unit 1005 is a part that processes the speed information notification packet VN1 from the MN8000 and extracts the speed information VI1. This speed information VI1 is information indicating its own current speed detected by the MN8000 itself, and arrives in a state of being contained in the speed information notification packet VN1.

【0049】

The position detection unit 1006 is a part that processes the position information notification packet PN1 from the MN8000 and extracts the position information PI1. This position information PI1 is information indicating the current position of the MN8000 itself measured by the MN using GPS or the like, and arrives in a state of being contained in the position information notification packet PN1.

【0050】

The prediction pattern holding unit 1010 is a part that stores and holds a plurality of prediction templates TL1. The movement prediction unit 1009 can search for an appropriate prediction template TL1 from the prediction pattern holding unit 1010 based on the speed information VI1 and the position information PI1. The search key used for this search corresponds to the speed information VI1 and the position information PI1.

【0051】

The prediction template TL1 is basic information effective for the movement prediction unit 1009 to obtain the prediction result information CN1 in a short time by a simpler arithmetic process. As the prediction template TL1, for example, the high-speed prediction template TL11 shown with diagonal lines in FIG. 10 (A) and the low-speed prediction template TL12 shown with diagonal lines in FIG. 10 (B) can be used. it can. Such a prediction template TL1 may be automatically created and held by the prediction putter holding unit 1010, or may be stored in the prediction pattern holding unit 1010 in advance.

【0052】

The prediction template TL1 used by the movement prediction unit 1009 for prediction needs to be able to identify the radius r of the radio zone and the movement speed of the MN8000 (specified by the speed information VI1) as search keys. Depending on how the prediction template TL1 is used, the radius of the circle portion (that is, the set value of the prediction template TL1) does not necessarily match the radius of the actual radio zone, but in the present embodiment, it is assumed that they match. doing. If the current position of the MN8000 is known based on the position information PI1, the radio zone to which the MN8000 belongs can also be known, so that the set value r required for the search can be specified based on the current position.

【0053】

The shape of the radio zone does not necessarily become a circle as shown in Fig. 20 when the AR as a radio base station does not use an omnidirectional antenna in the horizontal plane, and the shape of each radio zone The size (for example, radius r) is not always the same as shown, but here, for the sake of simplicity, a circular and the same size radio zone is assumed. Under such an assumption, there is only one set value r, so practically only the movement speed is the search key.

【0054】

In FIG. 10 (A), 10c corresponds to the set value r, and v1 is the moving speed. The current position of MN8000 is 10a (or 10g).

【0055】

The meaning of this high-speed prediction template TL11 is that the MN8000 is currently moving at a speed v1 in the direction from position 10a to position 10b, so that the probability of moving to position 10b, which is the center of the circular portion, after a predetermined time has elapsed. Is the highest, but considering the possibility of changing the velocity v1 and changing the direction of movement, it is not unlikely that it will move to another position inside the shaded prediction template TL11. Is. The highest probability is that if there is no change in the direction of movement or the speed v1, it will move to the position 10b.

【0056】

It should be noted that the movement to the shaded area other than the circular part in the prediction template TL11 is when the MN8000 suddenly reduces the movement speed from the v1. Further, the predetermined time is determined based on the time required for performing the context transfer and executing the handover process.

【0057】

The reason why the high-speed prediction template TL11 does not cover the movement from the position 10a to the opposite direction of the position 10c at all is that such movement occurs during the predetermined time when the movement speed is high. This is because the probability is considered to be extremely low.

【0058】

When v1> r holds, that is, when the MN8000 moves at a speed v1 within the predetermined time and the distance traveled by the MN8000 is longer than the set value r, the high-speed prediction template TL11 is used. ..

【0059】

Similarly, in FIG. 10 (B), 10d (or 10i) indicates the current position of the MN8000, v2 indicates the current moving speed of the MN8000, and 10e, which is the center of the circle, is the probability of moving most after the predetermined time. Indicates a high position. Again, the radius (set value) 10f of the circle coincides with the radius r.

【0060】

Unlike the high-speed prediction template TL11, the low-speed prediction template TL12 also covers movement from position 10d to the opposite direction of position 10e to some extent. This is because when the moving speed is low, the probability that a large fluctuation in the moving direction will occur is not necessarily low.

【0061】

When v2 <r holds, that is, when the distance that the MN8000 moves at the speed v2 within the predetermined time is shorter than the set value r, the low speed prediction template TL12 is used. ..

【0062】

Here, only two prediction templates, one for high speed and one for low speed, are typically shown, but it is natural that a large number of prediction templates that may exist in between these may be prepared depending on the moving speed and the like. .. By preparing many prediction templates, more accurate prediction becomes possible.

【0063】

The position data storage unit 1008 is a part that stores the radio zone information ZI regarding the neighboring AR and the own AR1000. The neighboring AR is a concept including the adjacent AR covering the adjacent radio zone and the indirect AR covering the indirect radio zone described above. If necessary, the geographical range of this neighboring AR may be extended to the outside of the indirect radio zones E11 to E22 on FIG. The need for expansion is that the upper limit of the moving speed of the MN8000 is extremely high compared to the size of the radio zone, and the MN8000 crosses two or more radio zones during one handover process. This is a case that may end up.

【0064】

Further, the radio zone information is information indicating the geographical position and size of the radio zone covered by each AR, and as an example, it can be configured by the latitude, longitude, radius, etc. of the radio zone. If necessary to detect the latitude and longitude of the radio zone, each AR may be equipped with a GPS system.

【0065】

The neighborhood AR location search unit 1007 is a part that exchanges the radio zone information by exchanging the radio zone information related packets ZN1 and ZN2.

【0066】

The wireless zone is not always statically stable, and like a mobile phone network, wireless base stations (corresponding to AR in this embodiment) are added, deleted, or changed to reflect the increase or change in traffic. If so, the radio zone will also change dynamically. In order to respond to such dynamic changes, the AR1000 needs to make inquiries about wireless zone information to neighboring ARs as appropriate, and conversely, if there are inquiries from neighboring ARs, it is necessary to respond to those inquiries. is there.

【0067】

In FIG. 1, the radio zone information of the AR1000 itself is ZI1, and the radio zone information of the neighboring AR is ZI2. In addition, the wireless zone information-related packet ZN1 is a packet that is transmitted to make an inquiry to a neighboring AR or respond to an inquiry from a neighboring AR, and the wireless zone information-related packet ZN2 is a packet that receives an inquiry from a neighboring AR or AR1000. It is a packet received to receive a response from a neighboring AR to an inquiry made by itself.

【0068】

Next, the internal configuration of the MN8000 connected to the AR1000 via a wireless link will be described with reference to FIG. The internal configuration of the MN other than the MN8000 housed in the mobile communication system of the present embodiment may be the same as that of the MN8000.

【0069】

(A-1-2) Example of internal configuration of MN In Fig. 8, the MN8000 has a control unit 8001, a communication unit 8002, a MIP processing unit 8003, an application processing unit 8004, a speed measuring unit 8005, and a position detection. It has a unit 8006 and a GPS unit 8007.

【0070】

As described above, the MN8000 of the present embodiment has a function of detecting its own current speed and obtaining the speed information VI1 and a function of detecting a position and obtaining the position information PI1. The speed measurement unit 8005 detects the speed, and the position detection unit 8006 detects the position.

【0071】

When the position detection unit 8006 obtains the position information PI1 from the GPS unit 8007, the position information PI1 is supplied to the speed measurement unit 8005. Since GPS is used, the accuracy of the current position of MN8000 indicated by the position information PI1 is quite high.

【0072】

The speed measurement unit 8005 is a part that calculates the speed information VN1 indicating the current moving speed of the MN8000 from the time change of the position indicated by the position information PI1.

【0073】

When the speed measurement unit 8005 completes the calculation of the speed information VN1, the speed measurement unit 8005 sends the speed information notification packet VN1 containing the speed information VN1 to the AR1000, and at almost the same time, the position information at that time. The location information notification packet PN1 accommodating PI1 is transmitted to the AR1000.

【0074】

The application processing unit 8004 is a part corresponding to the communication application and transmits / receives the above-mentioned data packet DP1. The type of communication application does not matter. As an example, assuming that the MN8000 is a mobile phone, a communication application for voice calls is basic, but if the mobile phone is equipped with a mailer, the mailer can also correspond to this communication application, and the Web. If the mobile phone is equipped with a browser, the Web browser may also fall under this communication application.

【0075】

The control unit 8001 corresponds to the control unit 1001, the communication unit 8002 corresponds to the communication unit 1002, and the MIP processing unit 8003 has a function corresponding to the MIP processing unit 1003.

【0076】

Hereinafter, the operation of the present embodiment having the above configuration will be described. The operation of this embodiment is roughly divided into an initialization operation and a handover processing operation. The initialization operation is a prerequisite operation for performing the handover processing operation.

【0077】

(A-2) Operation of the first embodiment (A-2-1) Initialization operation In the initialization operation, the AR1000 exchanges the radio zone information-related packets ZN1 and ZN2 with the neighboring AR, for example, periodically, and if necessary, the stored contents of the position data storage unit 1008. The radio zone information ZI is updated.

【0078】

However, if the configuration of the mobile communication system is very stable and ARs are rarely added, deleted, changed, or the wireless zone covered by each AR is rarely expanded, reduced, or transformed. It is also efficient to statically set the stored contents of the position data storage unit 1008 in advance. In that case, the neighborhood AR position search unit 1007 can be omitted.

【0079】

In any case, in order for the movement prediction unit 1009 of the AR1000 to predict the accurate movement destination of the MN8000, it is premised that accurate radio zone information regarding the neighboring AR is stored in the position data storage unit 1008. It becomes.

【0080】

Next, the handover processing operation will be described.

【0081】

(A-2-2) Handover processing operation For example, assuming that the radio zone covered by the AR1000 is the radio zone E0 in FIG. 20, the MN8000 appears in the radio zone E0 and starts wireless communication with the AR1000 as a radio base station. , MN8000 comes under the control of AR1000.

【0082】

In this state, the MN8000 can move in any direction and at any speed on FIG. 20.

【0083】

Assuming that the radio communication corresponds to a session for which communication continuity needs to be guaranteed, the MN8000 moves from radio zone E0 to another radio zone (eg, E1) while continuing the radio communication. In that case, the handover process is required.

【0084】

At this time, in the prediction process executed by the movement prediction unit 1009 in the AR1000, the processes shown in FIGS. 11 to 14 are executed by using the above-mentioned high-speed and low-speed prediction templates TL11 and TL12. 11 and 12 are cases where the low-speed prediction template TL12 is used, and FIGS. 12 and 13 are cases where the high-speed prediction template TL11 is used.

【0085】

Since the movement prediction unit 1009 can recognize the radio zone configuration around the radio zone E0 as shown in FIG. 20 from the stored contents of the position data storage unit 1008, the speed information VI1 obtained from the speed measurement unit 1005. When corresponds to v2, the low-speed prediction template TL2 shown in FIG. 10 (B) can be searched from the prediction putter holding unit 1010.

【0086】

On the other hand, since the position information PI1 obtained from the position detection unit 1006 indicates the precise current position of the MN8000, the wireless zone configuration and prediction are made so that the point 10i on the low-speed prediction template TL12 is superimposed on the current position 11a on FIG. By superimposing the template TL12, the movement prediction unit 1009 can obtain, for example, FIG. 11 or FIG. In this superposition, it is natural to consider the moving direction of the MN8000.

【0087】

Assuming that the arrow N in the figure points to the north, Fig. 11 shows the case where the current position of the MN8000 is near the outer edge of the radio zone E0 and is moving almost north-northeast, and Fig. 12 shows the case. , The current position of the MN8000 is near the center of the radio zone E0 and is moving northward.

【0088】

In the example of FIG. 11, there are three radio zones that two-dimensionally overlap with the prediction template TL12, E1, E2, and E12, excluding E0 itself. Therefore, the movement prediction unit 1009 performs the movement prediction unit 1009 after the lapse of the predetermined time. Means that the MN8000 predicted that it was moving to one of these three radio zones. Then, the prediction result information CN1 to that effect is supplied from the movement prediction unit 1009 to the next candidate AR determination unit 1004.

【0089】

Therefore, in this case, assuming that the next candidate AR determination unit 1004 does not perform further selection, the AR1000 transfers the context to the three neighboring ARs covering these three radio zones E1, E2, and E12. become. In this context transfer, the number of destinations is reduced to 1/6 compared to the case where the context is transferred to all 18 neighboring ARs for AR1000.

【0090】

Here, E1 and E2 correspond to the adjacent radio zone, and E12 corresponds to the indirect radio zone.

【0091】

Here, E12, which has a small overlapping area with the prediction template TL12, is treated in the same way as E2, which has a large overlapping area, but if necessary, the size of the overlapping area is a predetermined value. Neighboring ARs in that radio zone may be excluded from context transfer destinations if:

【0092】

In addition, since the movement probabilities to each point in the prediction template TL12 are not equal (for example, the movement probability to the point 10e is the highest), weighting is performed in consideration of the movement probability to each point in the prediction processing. You may do so. The process (sorting process) that takes into account the size of the overlapping area and the movement probability may be executed by the next candidate AR determination unit 1004.

【0093】

Other prediction processes are basically the same as in the case of FIG.

【0094】

However, in FIG. 12, E1, E2, E6 overlap with the prediction template TL12, in FIG. 13, E1, E2, E11, E12, E22 overlap with the prediction template TL11, and in FIG. 14, E1, E2, E1, E2, Since E6, E11, E12, E22 overlap with the prediction template TL11, in each case, the AR1000 will transfer the context to the neighboring ARs that cover each overlapping radio zone.

【0095】

Conventionally, the context was transferred only to the adjacent AR that covers the adjacent radio zone, but in the present embodiment, when the moving speed of the MN8000 is high, the context is also transferred to the indirect AR that covers the indirect radio zone. Since the transfer can be performed, the possibility that the MN moves to the radio zone of the AR that does not transfer the context can be reduced.

【0096】

The AR1000 performs the same operation as the conventional AR except for the initialization operation and the handover processing operation described above.

【0097】

(A-3) Effect of the first embodiment According to the present embodiment, the context transfer efficiency is high and smooth handover processing can be guaranteed, so that the communication quality is high and the communication reliability is also improved.

【0098】

(B) Second embodiment Hereinafter, only the differences between the present embodiment and the first embodiment will be described.

【0099】

In the first embodiment, since the position and speed of the MN8000 are substantially detected by the MN8000 itself, it cannot be applied to an existing MN that does not have such a function. It is characterized in that the AR side performs these detections.

【0100】

If these detections are performed on the AR side, the MN can use the existing ones that do not have the function of detecting the position and speed as they are, which improves the feasibility.

【0101】

(B-1) Configuration and operation of the second embodiment An example of the internal configuration of the AR7000 of this embodiment is shown in FIG. In this embodiment, since the AP (access point) is interposed between the MN and the AR, the overall configuration of the mobile communication system is the configuration shown in FIG. 6 described above. An example of the internal configuration of the AP9000 of this embodiment is as shown in FIG.

【0102】

In FIG. 7, the AR7000 includes a control unit 7001, a communication unit 7002, a MIP processing unit 7003, a next candidate AR determination unit 7004, a speed analysis unit 7005, a position analysis unit 7006, and a neighboring AP position search unit 7007. The position data storage unit 7008, the movement prediction unit 7009, the prediction pattern holding unit 7010, and the AP position storage unit 7011 are provided.

【0103】

In FIG. 7, the functions of the components given the same names as those in FIG. 1 are basically the same as those in the first embodiment, and the functions of the signals given the same reference numerals are also basically the same as in the first embodiment. Is.

【0104】

Further, as shown in FIG. 9, the AP9000 in which one or more are accommodated in one AR7000 includes a control unit 9001, a communication unit 9002, a MIP processing unit 9003, and a communication area position information storage unit 9004. It has.

【0105】

Also on FIG. 9, the functions of the components given the names corresponding to those in FIG. 1 are basically the same as those of the first embodiment, and the functions of the signals to which the corresponding codes are given are also basically the same as those of the first embodiment. Is the same as.

【0106】

However, in the present embodiment, it is the AP9000 that directly performs wireless communication with the MN, and the AR7000 is connected to the MN via the AP9000. The communication between AP9000 and AR7000 may be wireless communication or wired communication.

【0107】

Therefore, the neighboring AP position search unit 7007 mounted inside the AR7000 of the present embodiment exchanges radio zone information-related packets ZN1 and ZN2 not only with the neighboring AR but also with the AP9000 under the AR7000. Will do.

【0108】

The geographical position of the AR7000 itself of the present embodiment, which does not function as a radio base station, is irrelevant to the prediction process, but the radio zone information under its own (that is, one or more AP9000s under its own AR7000) Responding to inquiries from other ARs (radio zone information regarding one or more radio zones (subordinate radio zone clusters)) to be covered, or inquiring neighboring ARs for the subordinate radio zone information is the present embodiment. But it is necessary.

【0109】

If the radio zone 15f or the like is an individual subordinate radio zone on FIG. 15, the radio zone cluster refers to 15b.

【0110】

Although it depends on the processing performed in the AP9000, the handover processing in the present embodiment may occur not only between the wireless zone clusters but also within one wireless zone cluster. The case that occurs between the wireless zone clusters is the same as the first embodiment in that the context transfer is performed between the ARs, but the handover processing that occurs within the wireless zone cluster is each of the cases that make up the wireless zone cluster. Required when the MN moves between radio zones.

【0111】

For example, if the AP9000 is performing a decompression process corresponding to the compression protocol on the wireless link, the initialization information (also context) required for the decompression process constitutes the wireless zone cluster. Of the AP9000s that cover each radio zone, it can be transferred to the AP9000 to which the MN is moved. This transfer may be performed via AR7000, or may be performed directly between APs.

【0112】

The AP position storage unit 7011 of the present embodiment may be a part that stores the radio zone information like the position data storage unit 7008, but the position data storage unit 7008 is a radio zone that serves as basic information for prediction processing. In order to provide the information ZI to the movement prediction unit 7009, it is necessary to store the subordinate radio zone information for all neighboring ARs, whereas the AP location storage unit 7011 stores only the subordinate radio zone information of the AR7000 itself. It is enough to store it.

【0113】

In the first embodiment, the current position of the MN was measured with high accuracy using GPS, but in the present embodiment, the current position of the MN is determined by inspecting which AP9000 radio zone the MN belongs to. Identify. Therefore, the accuracy of the current position obtained in the present embodiment may be lower than that in the first embodiment, but after all, in the present embodiment, one radio zone (or one radio zone) is used. Since it is sufficient to be able to specify the destination of the MN with a fineness of about (wireless zone cluster), it is possible to obtain sufficient accuracy in practice by this method as well.

【0114】

When each AP7000 is identified by using a predetermined APID, in the initialization operation in the present embodiment, the position data storage unit 7008 and the AP position storage unit 7011 are in a format in which the APID and its radio zone information are associated with each other. Wireless zone information can be stored in.

【0115】

Further, if each MN is identified by using a predetermined MNID, the current position of each MN can be indicated by the pair of the APID of the AP covering the radio zone to which the MN belongs and the MNID of the MN. In the present embodiment, the location information PI1 accommodated in the location information notification packet PN1 is this pair.

【0116】

When the position analysis unit 7006 receives the position information notification packet PN1 from the subordinate AP9000, the position information (the pair) extracted from the position information notification packet PN1 is currently displayed from the AP storage unit 7011 using APID as a search key. Find the location of the radio zone to which the MN belongs (eg latitude, longitude). Then, the position analysis unit 7006 supplies the MNID included in the position information to the movement prediction unit 7009 as the position information PI1 together with the search result.

【0117】

The position information PI1 can include information such as the movement history of the MN obtained by the same operation over a plurality of APs and the measurement error of the current position determined according to the size of the radio zone to which the MN belongs.

【0118】

The speed analysis unit 7005, which receives the position information PI1 from the position analysis unit 7006, calculates the movement speed of the MN by calculating the movement displacement per unit time based on the movement history and the like. The speed is supplied to the movement prediction unit 7009 as VI1. Therefore, the speed analysis unit 7005 can obtain the moving speed VI1 without receiving the speed information notification packet VN1 from the outside like the speed measurement unit 1005 of the first embodiment.

【0119】

As described above, the accuracy of the current position obtained in the present embodiment may be lower than that in the first embodiment, and therefore the accuracy of the speed information VI1 is also lower than that in the first embodiment. Considering the possibility of becoming, the two-dimensional size of the prediction templates TL11 and TL12 when superimposing on the radio zone configuration as shown in FIG. 20 should be larger than that of the first embodiment. May be good.

【0120】

(B-2) Effect of the second embodiment According to the present embodiment, it is possible to obtain an effect substantially equivalent to the effect of the first embodiment.

【0121】

In addition, in the present embodiment, the existing MN can be used as it is as the MN, so that the feasibility is excellent.

【0122】

(C) Third embodiment Hereinafter, only the differences between the present embodiment and the first and second embodiments will be described.

【0123】

This embodiment differs from the first and second embodiments in that a domain management server is used. The domain management server has a function to respond to inquiries about wireless zone information about neighboring AR issued by AR. Therefore, in the present embodiment, it is not necessary to exchange the radio zone information-related packets ZN1 and ZN2 between the ARs.

【0124】

(C-1) Configuration and operation of the third embodiment Since the domain management server 19011 is used, an example of the overall configuration of the mobile communication system of this embodiment is shown in FIG. FIG. 19 is the same as FIG. 6 already described, except that the domain management server 19011 exists.

【0125】

The AR and AP in FIG. 19 may be the same as the AR7000 and AP9000 of the second embodiment. Therefore, the MN in FIG. 19 may be an existing MN.

【0126】

The internal configuration of the domain management server 19011 is the same as that of the domain management server 16000 shown in FIG.

【0127】

In FIG. 16, the domain management server 16000 includes a control unit 1601, a communication unit 16002, an AR location search unit 16003, and a location data storage unit 16004.

【0128】

On FIG. 16, the functions of the components given the same names as those in FIG. 1 are basically the same as those in the first embodiment. However, the domain management server 16000 communicates with AR and does not need to communicate with MN or AP.

【0129】

The position data storage unit 16004 is a part that stores the subordinate radio zone information of each AR in a format associated with the AR ID for identifying the AR. Since the domain management server 16000 centrally manages the subordinate radio zone information for a sufficiently larger number of ARs than the 19 described above, the location data storage unit 16004 stores a large number of ARIDs and subordinate radio zone information. Has been done.

【0130】

One ARID may be associated with subordinate radio zone information for all neighboring ARs around the AR specified by the ARID. If each AR recognizes its own ARID, if the neighboring AR inquiry packet AQ1 containing the ARID is sent to the domain management server 16000, the AR location search unit 16003 that received this packet AQ1 via the communication unit 16002. Can obtain all the desired subordinate radio zone information by searching the position data storage unit 16004 using the ARID as a search key, and stores the subordinate radio zone information in the response packet AQ2 to inquire about the neighboring AR. It can be returned to the AR that is the source of packet AQ1.

【0131】

Further, when each AR does not recognize its own ARID, each AR may accommodate its own subordinate radio zone information in the neighboring AR inquiry packet AQ1 and transmit it. Since the subordinate radio zone information includes location information such as longitude and latitude as described above, it is easy for the domain management server 16000 to identify the corresponding neighboring AR from the location information.

【0132】

(C-2) Effect of the third embodiment According to the present embodiment, it is possible to obtain an effect substantially equivalent to the effect of the second embodiment.

【0133】

In addition, in the present embodiment, each AR does not need to respond to inquiries from other ARs, so that the processing load can be reduced.

【0134】

Further, since the domain management server centrally manages a large number of subordinate wireless zone information, it becomes easy to manage the subordinate wireless zone information as a whole mobile communication system.

【0135】

(D) Fourth Embodiment Hereinafter, only the differences between the present embodiment and the first to third embodiments will be described.

【0136】

This embodiment is basically the same as the second embodiment, except that movement history information is added to the contents of the context.

【0137】

Since the movement history information cannot be said to be necessary information for guaranteeing the continuity of communication, it does not belong to the context concept from the above-mentioned definition of the original context, but in the present embodiment, the MN performed by each AR. In order to improve the accuracy of the movement prediction regarding, the movement history is passed between ARs.

【0138】

(D-1) Configuration and operation of the fourth embodiment An example of the overall configuration of the mobile communication system of the present embodiment is shown in FIG. 6 as in the second embodiment.

【0139】

However, as shown in FIG. 18, the internal configuration of the AR18000 of the present embodiment is different from that of the second embodiment.

【0140】

In FIG. 18, the AR18000 includes a control unit 18001, a communication unit 18002, a MIP processing unit 18003, a next candidate AR determination unit 18004, a speed analysis unit 18005, a position analysis unit 18006, and a neighboring AP position search unit 18007. It is provided with a position data storage unit 18008, a movement prediction unit 18009, a prediction pattern holding unit 18010, an AP position storage unit 18011, and a position information CT processing unit 18012.

【0141】

On FIG. 18, the functions of the components given the same names as those in FIG. 7 are basically the same as those of the second embodiment, and the functions of the signals given the same reference numerals are also basically the same as those of the second embodiment. Is.

【0142】

As is clear from the comparison between FIGS. 18 and 7, the difference between the AR18000 of the present embodiment and the AR7000 of the second embodiment is limited to the presence or absence of the position information CT processing unit 18012.

【0143】

The position information CT processing unit 18012 extracts the movement history information HS1 indicating the movement history of MN included in the position information PI1 supplied from the position analysis unit 18006 and supplies it to the MIP processing unit 18003. Further, this movement history information HS1 is accommodated in the context transfer packet CX1 and transferred to the neighboring AR (next candidate AR) narrowed down by the prediction process.

【0144】

Since the neighboring AR that received this transfer also has the same configuration as the AR18000, it is possible to add the movement history in its own subordinate radio zone cluster to the movement history information HS1 and transfer it to the next AR. Since the AR also repeats the same operation, it is possible to accumulate the movement history in many radio zone clusters.

【0145】

As long as the movement speed and movement direction of MN do not fluctuate abruptly and it is a static movement that can be statistically predicted from the past history, the more movement history is accumulated, the higher the accuracy of movement prediction can be. it can. In general movement of a moving object (for example, a car or a pedestrian), the situation where abrupt fluctuations occur is limited. Therefore, it is possible to improve the accuracy of movement prediction in general by such an operation. is there.

【0146】

There can be various types of static movement, such as movement that draws a linear locus, movement that draws a circular locus, and movement that circulates a locus of a specific shape many times.

【0147】

The timing at which the position analysis unit 18006 supplies the position information PI1 to the position information CT processing unit 18012 is the timing at which the control unit 18001 recognizes the necessity of handover processing and context transfer. In this embodiment, this timing is, for example, when the MN is located near the outer edge of the subordinate radio zone cluster of the AR18000.

【0148】

When the AR18000 receives a transfer of a context including movement history information from another AR, the context is received as a packet CX1 by the MIP processing unit 18003 via the communication unit 18002, so that the MIP processing unit 18003 is the packet. Only the movement history information HS2 is extracted from CX1 and supplied to the position information CT processing unit 18012.

【0149】

It goes without saying that the movement history information HS2 may be extracted from the packet CX1 not by the MIP processing unit 18003 but by the position information CT processing unit 18012 or the like.

【0150】

In addition, the position information CT processing unit 18012 supplies the movement history information HS2 to the position analysis unit 18006, and the timing of the supply is such that the MN actually moves into the subordinate radio zone cluster of the AR18000 by the control unit 18001. It may be after confirming that you have done so. If the MN does not move into the subordinate radio zone cluster of AR18000, the movement history information HS2 becomes unnecessary data that can be deleted, so it is not necessary to supply it to the position analysis unit 18006.

【0151】

(D-2) Effect of Fourth Embodiment According to this embodiment, an effect equivalent to that of the second embodiment can be obtained.

【0152】

In addition, in the present embodiment, it is possible to improve the accuracy of the prediction process by using the statistical movement characteristics of MN.

【0153】

(E) Fifth embodiment Hereinafter, only the differences between the present embodiment and the first to fourth embodiments will be described.

【0154】

This embodiment is basically the same as the third embodiment in that a domain management server is used, but there are differences in the functions of the domain management server.

【0155】

(E-1) Configuration and operation of the fifth embodiment An example of the overall configuration of the mobile communication system of this embodiment is shown in FIG. 19, and the MN in FIG. 19 may be an existing MN.

【0156】

However, the internal configuration of the domain management server 19011 on FIG. 19 is the domain management server 17000 shown in FIG. 17 in this embodiment.

【0157】

In FIG. 17, the domain management server 17000 includes a control unit 17001, a communication unit 17002, an AR location search unit 17003, a location data storage unit 17004, and a location history processing unit 17005.

【0158】

On FIG. 17, the functions of the components given the same names as those in FIG. 16 are basically the same as those of the third embodiment, and the functions of the signals given the same reference numerals are also basically the same as those of the third embodiment. Is.

【0159】

As is clear from the comparison between FIGS. 17 and 16, the difference between the domain management server 17000 of the present embodiment and the domain management server 16000 of the third embodiment is limited to the presence or absence of the location history processing unit 17005.

【0160】

The position history processing unit 17005 is a part that accumulates the position information received from each AR via the communication unit 17007 and records the movement history and movement speed of the MN. This recorded information can be used as billing and access records.

【0161】

Since location information is supplied to the domain management server 17000 from a large number of ARs, it is possible to centrally manage the movement history of MN in the mobile communication system.

【0162】

(E-2) Effect of the fifth embodiment According to the present embodiment, an effect equivalent to that of the third embodiment can be obtained.

【0163】

In addition, in the present embodiment, since it is possible to centrally manage the movement history of MN in the mobile communication system, it is convenient for billing, access recording, and the like.

【0164】

(F) Other embodiments Regardless of the first to fifth embodiments, the present invention omits the prediction pattern holding unit so that the movement prediction unit performs prediction processing related to the movement of MN without using the prediction template TL1. You can also do it.

【0165】

Further, the MIP processing unit may change the content of the context to be transferred according to the adjacency distance of the AR. For example, if the amount of data in the context to be transferred is large, such as when the number of hops to the destination AR is large, there is a high possibility that the movement of MN will be completed before the transfer is completed, so reduce the amount of data as much as possible. This is because it is preferable to do so.

【0166】

Further, for example, the movement history information and the like can be different for each context destination.

【0167】

Further, it is possible to adopt a plurality of configuration methods by changing the combination method of each device in the first to fifth embodiments.

【0168】

For example, it is possible to configure a mobile communication system in which AR having an AP under its control and AR without it (the AR itself also functions as a radio base station) coexist.

【0169】

Further, the GPS unit in the first embodiment can be replaced with another detection means for detecting the position or movement of the MN.

【0170】

Even if the information indicating the position and speed of the MN used in the prediction process is replaced with an ID that can be converted with the position of the MN, time information, etc., it is equivalent by appropriately changing the specifications of the prediction process. It is possible to obtain the prediction result information CN1.

【0171】

Further, it has already been explained that the next candidate AR determination unit in the first to fifth embodiments may further select the next candidate AR designated by the prediction result information CN1 based on a predetermined selection criterion. As you can see, the selection criteria are not limited to the size of the overlapping area and the movement probability described above.

【0172】

Further, the configurations of the respective devices (AR, AP, MN, domain management server) shown in the first to fifth embodiments are examples, and the configurations of these devices are deformable.

【0173】

Furthermore, since the overall configuration (FIGS. 2, 6, 6, 19, etc.) of the first to fifth embodiments is only an example, it can be combined with other network devices (not shown) or the network configuration can be changed. It is also possible to do.

【0174】

In the fourth embodiment, the movement history information is included in the context, but the movement history information may be transferred separately from various other information constituting the context.

【0175】

Further, in the first to fifth embodiments described above, the case of using MIP has been described as an example, but the present invention is widely applied to the case of performing handover processing regardless of whether or not MIP is used. Can be done.

【0176】

As an example, the present invention can be applied to networks such as car phones, PHS, PDAs, and mobile phones.

【0177】

In the above description, the present invention has been realized mainly in terms of hardware, but the present invention can also be realized in terms of software.

【0178】

[Effect of the invention]

As described above, according to the present invention, it is possible to improve the quality of communication and the reliability of communication by increasing the transfer efficiency of context information.

[Simple explanation of drawings]

[Figure 1]

It is the schematic which shows the structural example of the main part of AR which concerns on 1st Embodiment.

[Figure 2]

It is the schematic which shows the whole structure example of the mobile communication system of the prior art and the 1st Embodiment.

[Fig. 3]

It is the schematic which shows the structural example of the main part about the conventional AR.

[Fig. 4]

It is a schematic diagram which shows the structural example of the main part concerning the conventional MN.

[Fig. 5]

It is the schematic which shows the structural example of the main part with respect to the conventional access point.

[Fig. 6]

Conventionally, it is a schematic diagram which shows the overall structure example concerning the 2nd and 4th Embodiments and the like.

[Fig. 7]

It is a schematic diagram which shows the structural example of the main part concerning AR of the 2nd Embodiment and the like.

[Fig. 8]

It is the schematic which shows the structural example of the main part concerning MN of 1st Embodiment.

[Fig. 9]

It is the schematic which shows the structural example of the main part with respect to AP of 2nd Embodiment.

[Fig. 10]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Fig. 11]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Fig. 12]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Fig. 13]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Fig. 14]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Fig. 15]

It is operation explanatory drawing of the conventional and 2nd Embodiment and the like.

[Fig. 16]

It is a conventional operation explanatory drawing.

[Fig. 17]

It is the schematic which shows the configuration example of the main part of the domain management server of the 3rd Embodiment and the like.

[Fig. 18]

It is the schematic which shows the structural example of the main part about AR of 4th Embodiment.

[Fig. 19]

It is the schematic which shows the overall configuration example of the mobile communication system which concerns on 3rd and 5th Embodiment.

[Fig. 20]

It is operation explanatory drawing of 1st to 5th Embodiment.

[Explanation of symbols]

1000,2002,2003A, 2003B, 2004,3000,6002 ~ 6004, 7000,18000 ... AR (access router), 1004, 18004 ... Next candidate AR determination unit, 1005 ... Speed measurement unit, 1006. .. Position measurement unit, 1007 ... Neighborhood AR location search unit, 7007 ... Neighborhood AP location search unit, 1008 ... Position data storage unit, 1009 ... Movement prediction unit, 1010, 7010, 18010 .. .Prediction pattern holding unit, 4000,8000 ... MN (mobile node), 5000,9000 ... AP (access point), 7005 ... speed analysis unit, 7006 ... position analysis unit, 7011 ... AP position storage unit, 8005 ... speed measurement unit, 8006 ... position detection unit, 9004 ... communication area position information storage unit, 17003 ... AR position search unit, 17005 ... position history processing unit.