Mobile communication network and data delivery method in mobile communications network

A mobile communications network and data delivery method in a mobile communications network is provided that can implement connectionless transfer in the mobile communications network, and obviate the need for sending a call control signal for data delivery. An IP address is assigned to each of the nodes of the mobile communications network including routing nodes (a gate node and repeater node, for example) and edge nodes and to each mobile station. A routing node, receiving data including the IP address of a mobile station, carries out routing of the data in accordance with routing information. The edge node that receives the data routed by the routing node, transmits the data to the mobile station corresponding to the IP address of the mobile station added to the data. The IP addresses are also applicable to delivering data to users of the same group, or carrying out control like handover.

TECHNICAL FIELD

The present invention relates to a mobile communications network and a data delivery method in the mobile communications network.

BACKGROUND ART

Conventionally, to deliver (transmit) data from a server, or to transfer data between mobile stations in a mobile communications network, so-called connection-oriented transfer is carried out which searches for a location of a mobile station from its ID, and transfers a call control signal between nodes of the network, followed by the data delivery.

As for a plurality of users (mobile stations) belonging to the same group in an area supervised by the same edge node (for example, base station), the location of each user is identified by sending the call control signal, followed by the data delivery for each user.

Furthermore, although there is a so-called connectionless network that sends no call control signal at data transfer as is often seen in a normal fixed network Internet, there is no control (for example, handover control) applicable to such a case where the destination of the delivery moves incessantly.

Thus, the conventional data delivery method must transfer the call control signal between the nodes however small an amount of data to be delivered. As a result, it has problems of reducing node performance, requiring to develop complicated software, and increasing a system cost.

In addition, since it delivers data to user by user to deliver data to the users of the same group, it presents a problem of causing aggregation in the network, and increasing load of the data delivery server.

DISCLOSURE OF THE INVENTION

Therefore, an object of the present invention is to implement a connectionless network and connectionless transfer by assigning IP (Internet Protocol) addresses to individual nodes, location information servers, data delivery servers and mobile stations of a mobile communications network, and by carrying out data delivery using the IP addresses, thereby making it unnecessary to send the call control signal for the data delivery.

Another object of the present invention is to prevent aggregation of the network when delivering data to the users of the same group, thereby reducing the load of the data delivery server.

Still another object of the present invention is to implement control such as handover in a connectionless network by using the IP addresses.

In order to accomplish the above mentiond objects, according to the first aspect of the present invention, a mobile communications network of the present invention comprises: one or more routing nodes for receiving data to which the IP address of a mobile station is added, and for carrying out routing of the data in accordance with routing information; and one or more edge nodes for receiving the data routed by the routing nodes, and for transmitting the data to the mobile station corresponding to the IP address of the mobile station added to the data.

Here, the mobile communications network may further comprise a location information server for managing information about correspondence between the IP address of the mobile station and the IP address of the edge node that supervises the area visited by the mobile station, the routing nodes may include a gate node; the gate node may retrieve, by accessing the location information server, the IP address of the edge node supervising the area visited by the mobile station corresponding to the IP address of the mobile station added to the received data, and add the IP address of the edge node to the received data; the routing information may include information about correspondence between the IP address of the edge node and the transmission route; and the routing nodes may carry out the routing of the received data in accordance with the IP address of the edge node added to the received data and the routing information.

Here, when the mobile station moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the moving mobile station may notify the location information server of its own IP address and the IP address of the new edge node; and the location information server may update information about correspondence between the IP address of the moving mobile station and the IP address of the edge node supervising the area visited by the moving mobile station.

Here, when the mobile station moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the moving mobile station may transmit its own IP address and the IP address of the new edge node to the old edge node; and when the old edge node thereafter receives data to which the IP address of the moving mobile station is added, the old edge node may transmit the data to the new edge node with adding the IP address of the new edge node to the data.

Here, the routing information may include information about correspondence between the IP address of the mobile station and the transmission route, and the routing nodes may carry out the routing of the received data in accordance with the IP address of the mobile station added to the received data and the routing information.

Here, the IP address of a group of mobile stations can be added as the IP address of the mobile station to be added to the data, and the routing nodes may have group information which is information about correspondence between the IP addresses of the mobile stations belonging to the group and the IP address of the group of the mobile stations, replicate, when the IP address of the group of the mobile stations is added to the received data, the received data by the number of the transmission routes corresponding to the IP addresses of the mobile stations corresponding to the added IP address of the group of the mobile stations in accordance with the group information and the routing information and carry out the routing of the data.

Here, the IP address of the mobile station to be added to the data can include the IP addresses of a plurality of mobile stations, the routing nodes may replicate, when the IP addresses of the plurality of the mobile stations are added to the received data, the received data by the number of the transmission routes corresponding to the IP addresses of the plurality of the mobile stations in accordance with the routing information, add to each of the data, the IP addresses of the mobile stations corresponding to each of the transmission routes, and carry out the routing of the data.

Here, the mobile station, when it moves from the supervisory area of an old edge node to the supervisory area of a new edge node, may transmit its own IP address to the new edge node, and each node from the higher level routing node of the new edge node up to the junction routing node from which the transmission routes diverge to the old edge node and to the new edge node, may update its own routing information about the moving mobile station.

Here, the routing information may include information about correspondence between the IP address of the edge node and the transmission route, and the routing nodes may carry out the routing of the received data in accordance with the IP address of the edge node added to the received data and the routing information; and the mobile station may notify, when it moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the old edge node of its own IP address and the IP address of the new edge node, and the old edge node may transmit, when it thereafter receives data to which the IP address of the moving mobile station is added, the data to the new edge node with adding the IP address of the new edge node to the data.

Here, the mobile communications network may further comprise a data delivery server for delivering data, the data delivery server may deliver data to the mobile station in response to a request from the mobile station.

Here, the mobile communications network may further comprises: a location information server for managing information about correspondence between the IP address of the mobile station and the IP address of the edge node that supervises the area visited by the mobile station, each of the edge nodes may receive data which is transmitted by a mobile station visiting its own supervisory area and to which the IP address of the mobile station is added, retrieve by accessing the location information server the IP address of the edge node supervising the area visited by the mobile station corresponding to the IP address of the mobile station added to the received data, add the IP address of the edge node to the received data, and transmit the data to the routing node; the routing information may include information about correspondence between the IP address of the edge node and the transmission route; and the routing nodes may carry out the routing of the received data in accordance with the IP address of the edge node added to the received data and the routing information.

Here, the edge node may generate and manage information about correspondence between the IP address of the mobile station added to the received data and the IP address of the edge node supervising the area visited by the mobile station.

Here, when the mobile station moves from the supervisory area of an old edge node to the supervisory area of a new edge node during communication with another mobile station, the moving mobile station may transmit its own IP address and the IP address of the new edge node to the edge node supervising the area visited by the party mobile station; and the edge node may update information about correspondence between the IP address of the moving mobile station and the IP address of the edge node supervising the area visited by the moving mobile station.

Here, when the mobile station moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the moving mobile station may transmit its own IP address and the IP address of the new edge node to the old edge node; and when the old edge node thereafter receives data to which the IP address of the moving mobile station is added, the old edge node may transmit the data to the new edge node with adding the IP address of the new edge node to the data.

Here, when the mobile station moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the moving mobile station may notify the location information server of its own IP address and the IP address of the new edge node; and the location information server may update information about correspondence between the IP address of the moving mobile station and the IP address of the edge node supervising the area visited by the moving mobile station.

Here, each of the edge nodes may receive data which is transmitted by a mobile station visiting its own supervisory area and to which the IP address of the mobile station is added, and transmit the data to the routing node; the routing information may include information about correspondence between the IP address of the mobile station and the transmission route; and the routing nodes may carry out the routing of the received data in accordance with the IP address of the mobile station added to the received data and the routing information.

Here, the mobile station, when it moves from the supervisory area of an old edge node to the supervisory area of a new edge node, may transmit its own IP address to the new edge node, and each node from the higher level routing node of the new edge node up to the junction routing node from which the transmission routes diverge to the old edge node and to the new edge node, and from the junction routing node to the higher routing node of the old edge is node, may update its own routing information about the moving mobile station.

Here, the routing information may include information about correspondence between the IP address of the edge node and the transmission route, and the routing nodes may carry out the routing of the received data in accordance with the IP address of the edge node added to the received data and the routing information; and the mobile station may notify, when it moves from the supervisory area of an old edge node to the supervisory area of a new edge node, the old edge node of its own IP address and the IP address of the new edge node, and the old edge node may transmit, when it thereafter receives data to which the IP address of the moving mobile station is added, the data to the new edge node with adding the IP address of the new edge node to the data.

According to the second aspect of the present invention, a data delivery method in a mobile communications network including one or more routing nodes and one or more edge nodes, the data delivery method of the present invention comprises the steps of: receiving, at one of the routing nodes, data to which the IP address of a mobile station is added, and carrying out routing of the data in accordance with routing information; and receiving, at one of the edge nodes, the data routed by the routing nodes, and transmitting the data to the mobile station corresponding to the IP address of the mobile station added to the data.

The foregoing configurations can implement the connectionless network and connectionless transfer with obviating the need for sending the call control signal for the data delivery in the mobile communications network.

In addition, they can prevent the network aggregation that can conventionally take place in the data delivery to users of the same group, thereby reducing the load of the data delivery server.

Furthermore, they can implement the control such as the handover in the connectionless network.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the invention will now be described in detail.

First Embodiment

FIG. 1is a block diagram showing a configuration of a mobile communications network of the first embodiment in accordance with the present invention.

The mobile communications network of the present embodiment comprises a data delivery server101, gate node102, repeater nodes103and104, edge nodes105–108, and a location information server100.

The data delivery server101, gate node102, repeater nodes103and104, and edge nodes105–108have IP addresses (#1, #2, #3, #4, and #5–#8, respectively, in the present embodiment), and a mobile station109also has an IP address (#9 in the present embodiment).

The gate node102and the repeater nodes103and104are routing nodes for carrying out data routing in accordance with routing information.

FIG. 2is a flowchart illustrating an example of a data delivery method of the mobile communications network of the first embodiment in accordance with the present invention.

The data delivery server101manages the IP address of a mobile station to which data (IP packet) is to be delivered, and transmits the data along with the IP address of the mobile station to the gate node102(step S101).

The gate node102accesses the location information server100to capture the IP address of the edge node supervising the area visited by the mobile station corresponding to the IP address of the mobile station added to the received data (step5102).

The location information server100manages the IP address of the edge node supervising the area visited by the mobile station corresponding to the IP address. As an example of the location information server100, there is a home location register (HLR) or a visiting location register (VLR).

After capturing the IP address of the edge node by accessing the location information server100, the gate node102adds the IP address of the edge node to the received data (step S103), that is, encapsulates the received IP packet for the mobile station into the IP packet for the edge node, and transmits it to the repeater node (step S104).

Incidentally, apart from the example ofFIG. 1, it is also possible to configure the network in such a manner that the gate node is directly connected to the edge nodes without the repeater nodes. In this case, the gate node transmits the data directly to the edge nodes.

FIG. 3is a diagram showing an example of a format of the IP packet (data) to be transferred in the mobile communications network. The IP packet shown inFIG. 3is an IP packet associated with user information that includes the IP address of the edge node added thereto. In the format as shownFIG. 3, the reference symbol UD (User Data) designates data to be delivered, UIP (User IP) designates the IP address of the mobile station, and DGA (Destination Gatewaynode Address) designates the IP address of the edge node. The reference symbol UI (User Information) is an identifier indicating that the IP packet is the user information, which is added to distinguish it from an IP packet associated with control information. As for the IP packet associated with the control information, it includes an identifier indicating that the IP packet carries the control information. The UIP is added by the data delivery server101, and the DGA is added by the gate node102.

In the present embodiment, the gate node102records the correspondence between the IP address of the mobile station it captures by accessing the location information server and the IP address of the edge node so that the gate node utilizes the correspondence in the subsequent processing without accessing the location information is server100. However, it is also possible for the gate node102to access the location information server100every time it receives the data to capture the correspondence without recording the correspondence.

The gate node102has routing information (routing table) that includes transmission route information about the IP address of the edge node. In the example as shown inFIG. 1, the gate node102has the routing information that the route for the edge node105with the IP address #5is the repeater node103with the IP address #3. Accordingly, the gate node102that receives the data with the IP address of the edge node #5transmits the data to the repeater node103.

In accordance with the IP address of the edge node added to the received data, the repeater node103or104transmits the data to another repeater node or the edge node (edge node in the network configuration as shown inFIG. 1) (step S104). The repeater nodes103and104also have routing information that includes the transmission route information about the IP address of the edge node.

In the example as shown inFIG. 1, the repeater node103has the routing information that the route for the edge node105with the IP address #5is the edge node105itself with the IP address #5(in this case, the next transmission destination is the destination node itself).

Receiving the data (step S105), one of the edge nodes105–108transmits the data to the mobile station with the is IP address added to the received data. Specifically, it extracts the encapsulated IP packet for the mobile station, and transmits it to the mobile station (step S106). In the example as shown inFIG. 1, the edge node105, receiving the data with the IP address #9of the mobile station109, transmits the data to the mobile station109.

Thus, the mobile station109receives the data addressed to itself from the edge node (step S107).

The foregoing configuration and procedure can implement a connectionless network and connectionless transfer that obviate the need for sending the data call control signal for the delivery.

It is also possible to add the IP address of a group of mobile stations as the IP address of the mobile station to be added to the data (the IP address of the mobile station to receive the data delivery). In this case, the location information server100, for example, manages the information (group information) of the IP address of the edge node supervising the area visited by the mobile stations which belong to the group corresponding to the IP address of the group of the mobile stations.

When the IP address of the group of the mobile stations is added to the received data, the gate node102accesses the location information server100to capture the IP addresses of the edge nodes supervising the areas visited by the mobile stations corresponding to the IP address, that is, the mobile stations which belong to the group.

When the mobile stations belonging to the group are spread over supervisory areas of a plurality of edge nodes, the gate node102captures a plurality of the IP addresses of the edge nodes. The gate node102replicates the received data by the number of (the IP addresses of) the edge nodes captured. It adds to each data the IP address of the edge node, and the IP addresses of the mobile station visiting the supervisory area of the edge node.

The edge node replicates the data by the number of the mobile stations and transmits them to the respective mobile stations. Alternatively, a particular group ID can be assigned to all the mobile stations belonging to the same group so that the edge node can broadcast the data with adding the group ID. Thus, only the mobile stations with the group ID (belonging to the group) can capture the data.

As for the participation of the mobile stations in the group, it can be either fixed or temporary. Alternatively, the location information server100can have its own IP address so that the users of the mobile stations can access the location information server100using the IP address to conduct group registration.

Thus, enabling addition of the IP address of the group of the mobile stations can obviate the need for delivering data to each mobile station, reducing the load of the data delivery server. Furthermore, transmitting the data on the edge node by edge node basis can prevent the network aggregation.

The data delivery server101can be designed such that it can deliver data to the mobile station109in response to its request. For example, the mobile station109transmits data to the data delivery server101with adding the IP address of the data delivery server101to the data including information about the data to be delivered and the IP address of the mobile station109. Receiving the data, the data delivery server101transmits the requested data to the mobile station109with adding the IP address of the mobile station109.

FIG. 4is a block diagram illustrating an example of the first handover control in the mobile communications network of the first embodiment in accordance with the present invention, andFIG. 5is a flowchart illustrating the example of the first handover control in the mobile communications network of the first embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station109moves from the supervisory area of the edge node105to that of the edge node106.

The edge nodes105–108each broadcast their own IP addresses to their supervisory areas. The mobile station109receives one of the IP addresses the edge nodes broadcast, and stores it.

When the broadcast IP address differs from the currently stored IP address, the mobile station109decides315that its visiting area changes, and notifies the location information server100of its own IP address and the IP address of the new edge node via the gate node102(step S201). In the example ofFIG. 4, the mobile station109notifies the location information server100of its own IP address and the IP address of the edge node106via the edge node106, repeater node103and gate node102, for example.

If the gate node102has already established, in the form of table, for example, the relationship between the received IP address of the mobile station and the IP address of the edge node visited by the mobile station by having accessed the location information server100, it updates the table to bring the IP address of the mobile station into correspondence with the received IP address of the new edge node (step S202). The location information server100also updates its information to bring the two IP addresses into correspondence (the update is carried out regardless of whether the gate node102has the table or not) (step S203).

In the example ofFIG. 4, the IP address of the edge node the mobile station109visits is changed from #5 to #6. When the gate node102holds the relationship between the IP address of the mobile station and that of the edge node, it updates the relationship. After the update, the gate node102transmits the data to which the IP address #9 of the mobile station109is added after adding the IP address of the edge node #6 to the data.

In this way, the handover control is implemented in the connectionless network.

FIG. 6is a block diagram illustrating an example of the second handover control in the mobile communications network of the first embodiment in accordance with the present invention, andFIG. 7is a flowchart illustrating the example of the second handover control in the mobile communications network of the first embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station109moves from the supervisory area of the edge node105to that of the edge node106.

The edge nodes105–108each broadcast their own IP addresses to their supervisory areas. The mobile station109receives one of the IP addresses the edge nodes broadcast, and stores it.

Detecting that the broadcast IP address differs from the currently stored IP address, the mobile station109decides that its visiting area changes, and transmits its own IP address and the IP address of the new edge node to the old edge node (step S301). In the example ofFIG. 6, the mobile station109transmits its own IP address #9and the IP address #6of the new edge node106to the edge node105. The transmission to the edge node105is carried out via the edge node106and repeater node103, for example.

The old edge node creates a transfer table establishing the relationship between the IP address of the mobile station and the IP address of the new edge node (redirection edge node) (S302) so that when the old edge thereafter receives data to which the IP address of the mobile station is added, it transmits (transfers) the data to the new edge node with adding the IP address of the new edge node to the data. In the example ofFIG. 6, when receiving the data to which the IP address #9of the mobile station109is added, the edge node105transmits the data to the edge node106with adding the IP address #6of the edge node106to the data.

In this way, the handover control can be implemented in the connectionless network. Using the second handover control can reduce the data (packet) loss as compared with using the first handover control.

In the second handover control, however, there is a possibility of transmission delay or aggregation (aggregation between the edge node105and repeater node103ofFIG. 6, for example) because the data is transferred from the first visiting edge node of the mobile station.

Therefore, it is possible to update the location information server100as in the first handover control at some opportunity.

As the opportunity for the update, it will be possible to utilize the end of the current communication, the elapse of a predetermined time period after the exhaustion of the data, and the like. It will also be possible to update is after a predetermined time period has elapsed from the start of the transfer to the new edge node by the old edge node. Alternatively, if the traffic of some edge node exceeds a threshold value, that edge node carries out the update associated with the IP address of the mobile station to which the edge node transfers.

The update of the location information server100is implemented when the old edge node transfers the IP address of the mobile station and that of the new edge node to the gate node102. After transferring the IP addresses, the old edge node releases its own transfer table, which is preferably carried out after it receives the notification from the gate node102that the update of the location information server100is completed, to prevent data (packet) loss.

Second Embodiment

The second embodiment in accordance with the present invention carries out routing by the IP address of the mobile station.

FIG. 8is a block diagram showing a configuration of a mobile communications network of the second embodiment in accordance with the present invention. It will now be described with placing emphasis on the difference from the mobile communications network of the first embodiment in accordance with the present invention.

The mobile communications network of the present embodiment comprises a data delivery server201, a gate node202, repeater nodes203and204, and edge nodes205–208, but not a location information server.

The data delivery server201, gate node202, repeater nodes203and204and edge nodes205–208have IP addresses (#1, #2, #3, #4and #5–#8in the present embodiment), and a mobile station209has an IP address (#9in the present embodiment).

The gate node202and repeater nodes203and204are a routing node that carries out data routing in accordance with the routing information.

FIG. 9is a flowchart illustrating an example of a data delivery method of the mobile communications network of the second embodiment in accordance with the present invention.

The data delivery server201manages the IP address of a target mobile station of the data (IP packet) delivery, and transmits the data to the gate node202with adding the IP address of the mobile station to the data (step S401) as in the first embodiment in accordance with the present invention.

The gate node202carries out the routing of the data in accordance with the IP address of the mobile station added to the received data (step S402). The gate node202possesses the routing information including transmission route information about the IP address of the mobile station. The gate node202has the transmission route information on all (IP addresses of) the mobile stations.

In the example ofFIG. 8, the gate node202has routing information that a route for the edge node supervising the visiting area of the mobile station209with the IP address #9is the repeater node203with the IP address #3. Therefore, when receiving data to which the IP address of the mobile station #9is added, the gate node202transmits the data to the repeater node203.

The present embodiment which carries out the routing according to the IP address of the mobile station differs from the first embodiment that carries out the routing according to the IP address of the edge node. Thus, the location information server is not needed.

The repeater node203or204also transmits the received data to another repeater node or edge node in accordance with the IP address of the mobile station added to the data (step S402). Both the repeater nodes203and204have the routing information that includes transmission route information about the IP address of the mobile station. The repeater nodes203and204have the transmission route information about the (IP addresses of the) mobile stations visiting the supervisory areas of the edge nodes under their control.

In the example ofFIG. 8, the repeater node203has the routing information that the route for the edge node supervising the visiting area of the mobile station209with the IP address #9 is the edge node205with the IP address #5.

Receiving the data (step S403), one of the edge nodes205–208transmits the data to the mobile station with the IP address added to the received data (step S404), so that the mobile station209receives the data addressed and transmitted thereto from the edge node (step S405), as in the first embodiment in accordance with the present invention.

The foregoing configuration and procedure can implement the connectionless network and connectionless transfer that can obviate the need for sending the call control signal in the data delivery.

In the present embodiment, although the total amount of the routing information of the network increases as compared with that of the first embodiment in accordance with the present invention, it can eliminate the central management (location information server).

The IP address of a group of mobile stations can be added as the IP address of the mobile station to be added to the data.

In this case, the gate node202and the repeater nodes203and204, for example, have information (group information) about the IP addresses of the edge nodes supervising the areas visited by the mobile stations which belong to the group with the IP address of the group.

When the IP address of the group of the mobile stations is added to the received data, the gate node202and repeater nodes203and204capture the IP addresses of the mobile stations corresponding to the IP address of the group in accordance with the group information, first. Subsequently, they capture transmission routes corresponding to the IP addresses of the mobile stations in accordance with the routing information. The gate node202and repeater nodes203and204replicate the received data by the number of the captured transmission routes, and transmit the data to the mobile stations. Since the IP address of the group of the mobile stations is added to the data, a similar processing is carried out at the next repeater node. The data is replicated by the number of the mobile stations by the edge nodes, and transmitted to the mobile stations.

As for the group information, the gate node202can transmit it along with the data, or can possess it in advance and notify the repeater nodes203and204of it by broadcasting. It is enough for the gate node202and repeater nodes203and204to have the group information at the time when carrying out the routing of the data to which the IP address of the group is added. Accordingly, it is possible to design such that the gate node202broadcasts the group information to the repeater nodes203and204every time it carries out the routing of the data to which the IP address of the group is added, and deletes the group information after the repeater nodes203and204each carry out the routing of the data.

Thus enabling the IP address of the group of the mobile, stations to be added can obviate the need for delivering the data to each of the mobile stations, thereby reducing the load of the data delivery server. In addition, since the data is replicated and transmitted only when necessary, the network aggregation can be prevented.

Furthermore, the IP addresses of a plurality of mobile stations can be added as the IP address of the mobile station to be added to the data.

When the IP addresses of a plurality of mobile stations are added to the received data, the gate node202and repeater nodes203and204capture transmission routes corresponding to the IP addresses of the mobile stations in accordance with the routing information. The gate node202and repeater nodes203and204replicate the received data by the number of the captured transmission routes, and add to each of the data the IP addresses of the mobile stations corresponding to each of the transmission routes. Then, they transmits the data to the mobile stations. The edge nodes replicate the data by the number of the mobile stations, and transmit them to the mobile stations.

Assume that the example ofFIG. 8has three mobile stations each of which visiting one of the supervisory areas of the edge nodes205–207. Receiving the data to which the IP addresses of the three mobile stations are added, the gate node202generates two replicas of the data, and sends them to the repeater nodes203and204. The repeater node203generates two replicas of the data, and transmits them to the edge nodes205and206. On the other hand, the repeater node204transmits the data (without replicating the data) to the edge node207.

In this way, enabling the plurality of the IP addresses of the mobile stations to be added can obviate the need for delivering the data to each of the mobile stations, thereby reducing the load of the data delivery server. In addition, since the data is replicated and transmitted only when necessary, the network aggregation can be prevented.

A configuration is also possible which enables the data delivery server201to deliver data to the mobile station209in response to a request from the mobile station209as in the first embodiment in accordance with the present invention.

FIG. 10is a block diagram illustrating an example of the first handover control in the mobile communications network of the second embodiment in accordance with the present invention, andFIG. 11is a flowchart illustrating the example of the first handover control in the mobile communications network of the second embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station209moves from the supervisory area of the edge node205to that of the edge node206.

The edge nodes205–208each broadcast their own IP addresses to their supervisory areas. The mobile station209receives one of the IP addresses the edge nodes broadcast, and stores it.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station209decides that its visiting area changes, and transmits its own IP address to the new edge node (step S501). In the example ofFIG. 10, the mobile station209transmits its own IP address to the edge node206.

The new edge node transmits the IP address of the moving mobile station to the higher level routing node (repeater node or gate node) (step S502). The routing node that receives the IP address of the mobile station updates its own routing information about the (IP address of the) mobile station (or creates new information when there is no information about the mobile station) (step S503). Subsequently, it transmits the IP address of the mobile station to a still higher level routing node. Such a processing is repeated up to the routing node from which two transmission routes diverge to the old edge node and to the new edge node (steps S504and S505).

In the example ofFIG. 10, the higher level routing node of the new edge node is the repeater node203, and the routing node from which the transmission routes diverge into the old edge node (edge node205) and the new edge node (edge node206) is also the repeater node203. Accordingly, the repeater node203updates the routing information about the (IP address of the) mobile station is209, and changes the route from the edge node205(IP address #5) to the edge node206(IP address #6).

Here, consider an example in which the mobile station209moves from the supervisory area of the edge node206to that of the edge node207. In this case, the higher level routing node of the new edge node is the repeater node204, and the routing node from which the transmission routes diverge into the old edge node (edge node206) and the new edge node (edge node207) is the gate node202. Accordingly, the repeater node204and the gate node202update the routing information about the (IP address of the) mobile station209.

To distinguish the junction routing node from which the transmission routes diverge into the old edge node and the new edge node, a method can be conceived in which routing is always carried out to the higher level routing node at the routing nodes other than the routing nodes on the transmission route from the highest level node (the gate node202in the example ofFIG. 10) to the edge node supervising the area visited by the mobile station. Checking the routing information successively in ascending order from the higher level routing node of the new edge node, if the routing node has the routing information indicating a route to a lower level routing node, that routing node is identified as the junction node.

Likewise, a method can be conceived in which no routing information about the mobile station is provided to the routing nodes other than the routing nodes on the transmission route from the highest level node (the gate node202in the example ofFIG. 10) to the edge node supervising the area visited by the mobile station. Checking the routing information in ascending order from the new edge node to the higher level routing node successively, if the routing node has the routing information about the moving mobile station, that routing node is identified as the junction node.

To apply the foregoing methods, after updating the routing information from the higher level routing node of the new edge node up to the junction routing node, the routing information about the moving mobile station is updated from the lower level routing node of the junction routing node down to the higher level routing node of the old edge node (updates the routing information such that data is transmitted to the higher level node, or eliminates the routing information). The signal for updating the routing information can be made and notified either by the junction routing node or by the new edge node.

Besides the foregoing methods, a method is possible in which tracing a route from the new edge node up to the highest level node, the routing nodes update the routing information about the moving mobile station so that the data addressed to the mobile station is transmitted from the highest level node to the new edge node.

The foregoing update methods of the routing information are applicable to the power up of the mobile station.

In this way, the handover control can be implemented in the connectionless network.

FIG. 12is a block diagram illustrating an example of the second handover control in the mobile communications network of the second embodiment in accordance with the present invention, andFIG. 13is a flowchart illustrating the example of the second handover control in the mobile communications network of the second embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station209moves from the supervisory area of the edge node205to that of the edge node206.

The edge nodes205–208each broadcast their own IP addresses to their supervisory areas. The mobile station209receives one of the IP addresses the edge nodes broadcast, and stores it.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station209decides that its visiting area changes, and transmits its own IP address and the IP address of the new edge node to the old edge node (step S601). In the example ofFIG. 12, the mobile station209transmits its own IP address #9and the IP address #6of the edge node206to the edge node205. The transmission to the edge node205is carried out by placing information about correspondence between the IP address of the edge node and the transmission route into the routing information of each routing node as illustrated inFIG. 12, for example.

The old edge node creates a transfer table establishing the relationship between the IP address of the mobile station and the IP address of the new edge node (redirection edge node) (S602) so that when the old edge node thereafter receives data to which the IP address of the mobile station is added, it transmits (transfers) the data to the new edge node with adding the IP address of the new edge node to the data. In the example ofFIG. 12, when receiving the data to which the IP address #9of the mobile station209is added, the edge node205transmits the data to the edge node206with adding the IP address #6of the edge node206to the data. Thus, the transmission to the new edge node206is carried out by placing the transmission route information about the IP address of the edge node into the routing information of the routing nodes as described above.

In this way, the handover control can be implemented in the connectionless network. Using the second handover control can reduce the data (packet) loss as compared with using the first handover control.

In the second handover control, however, there is a possibility of transmission delay or aggregation (aggregation between the edge node205and repeater node203ofFIG. 12, for example) because the data is transferred from the first visiting edge node of the mobile station. Therefore, it is possible to update the routing information of the repeater node as in the first handover control at some opportunity.

As for the opportunity for the update, it is analogous to that of the first embodiment in accordance with the present invention.

The update of the routing information is implemented from the higher level routing node of the new edge node to the junction node as in the first handover control, for example. The release of the transfer table of the old edge node is preferably carried out after the update of the routing information of the junction node to prevent the data (packet) loss.

As described above, the second embodiment in accordance with the present invention can obviate the need for the location information server. In other words, it is possible for the network to carry out the data delivery, handover control and the like in the mobile communications without installing the location information server such as HLV and VLR for registering locations of users.

The third embodiment in accordance with the present invention implements data transfer between mobile stations. The routing is carried out using the IP addresses of the edge nodes as in the first embodiment.

FIG. 14is a block diagram showing a configuration of a mobile communications network of the third embodiment in accordance with the present invention.

The mobile communications network of the present embodiment comprises a gate node302, repeater nodes303and304, edge nodes305–308, and a location information server300. The functions of the nodes and the server are the same as those of their counterparts in the first embodiment.

The gate node302, repeater nodes303and304, and edge nodes305–308have their own IP addresses (#2, #3, #4, and #5–#8, respectively, in the present embodiment), and mobile stations309and310also have their own IP addresses (#9and #10in the present embodiment).

The gate node302and the repeater nodes303and304are a routing node for carrying out routing of the data in accordance with routing information.

FIG. 15is a flowchart illustrating part of a data transfer method between mobile stations in the mobile communications network of the third embodiment in accordance with the present invention.

Assume that a mobile station (309, for example) transmits data (IP packet) with adding the IP address (#10) of a party mobile station (310, for example) to the edge node (305, in this case) (step S701).

The edge node accesses the location information server300to retrieve the IP address of the edge node supervising the area visited by the mobile station corresponding to the IP address of the mobile station added to the received data (S702). In the present embodiment, the edge node generates information (table) about the retrieved relationship and manages it. After that, there is no need to access the location information server300, though it is also possible to design to access the location information server300every time the packet is received (in which case, the table is not needed). Alternatively, it is also possible to design to access the location information server300periodically to update the table (in which case, the load of the location information server300is reduced as compared with the case that accesses it for each packet).

After retrieving the IP address of the edge node by accessing the location information server300, the edge node adds the IP address of the edge node to the received data (S703), that is, encapsulates the received IP packet for the mobile station into the IP packet for the edge node, and transmits it to the routing node (S704).

In the example ofFIG. 14, since each edge node is connected with only one repeater node, the data is transmitted to the corresponding one of the repeater nodes.

The edge node, however, can be connected to a plurality of repeater nodes, in which case, the edge node carries out routing in accordance with the IP address of the destination edge node of the data. The subsequent routing of the data is analogous to that of the first embodiment. For example, the data transmitted from the mobile station309to the mobile station310is transmitted through the edge node305, repeater node303and edge node306, and arrives at the mobile station310. The data transmission from the mobile station310to the mobile station309is carried out in a similar manner.

FIG. 16is a block diagram showing an example of the table the edge node generates and manages in the mobile communications network of the third embodiment in accordance with the present invention. The edge node305, receiving the data for the mobile station310from the mobile station309, identifies that the edge node of the mobile station310is the edge node306, and generates and manages the table as shown inFIG. 16. Likewise, the edge node306, receiving the data for the mobile station309from the mobile station310, identifies that the edge node of the mobile station309is the edge node305, and generates and manages the table as shown inFIG. 16.

FIG. 17is a block diagram illustrating an example of the first handover control in the mobile communications network of the third embodiment in accordance with the present invention, andFIG. 18is a flowchart illustrating the example of the first handover control in the mobile communications network of the third embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station310moves from the supervisory area of the edge node306to that of the edge node307.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station310decides that its visiting area changes, and transmits its own IP address and the IP address of the new edge node to the edge node (party edge node, in this case the edge node305) supervising the visiting area of the party mobile station (mobile station309) (S801).

A few methods are conceivable of transmitting the newly corresponding two IP addresses (the IP address of the mobile station310and the IP address of the edge node307) to the party edge node. For example, there is a method in which the moving mobile station310notifies the new edge node307of the IP address of the party mobile station309, so that the edge node307accesses the location information server300to retrieve the edge node (edge node305) of the mobile station309, and transmits the newly corresponding two IP addresses to the edge node305.

Alternatively, the moving mobile station310notifies the new edge node307that the old edge node is the edge node306, so that the new edge node307transmits the newly corresponding two IP addresses to the old edge node306, and the edge node306transmits the newly corresponding two IP addresses to the edge node305(the old edge node306knows from its own table that the mobile station310is communicating with the mobile station309, and that the edge node of the mobile station309is the edge node305). Using the method enables the edge node306to eliminate the table about the mobile station310, which becomes unnecessary.

There is still another method in which in the foregoing two methods, the edge node307or edge node306notifies the location information server300to update the information about the mobile station310(notifies it of the newly corresponding two IP addresses), so that the location information server300notifies the edge node305to update the information (table) about the mobile station310(notifies it of the newly corresponding two IP addresses).

The edge node305updates its own table in accordance with the received newly corresponding two IP addresses such that the IP address of the mobile station310corresponds to the IP address of the edge node307(S802).

In the example ofFIG. 17, the edge node305changes in its own table the IP address of the edge node the mobile station310visits from #6to #7. After that, the edge node305transmits the data to which the IP address #10of the mobile station310is added with adding the IP address #7of the edge node307to the data.

FIG. 19is a block diagram illustrating an example of the second handover control in the mobile communications network of the third embodiment in accordance with the present invention, andFIG. 20is a flowchart illustrating the example of the second handover control in the mobile communications network of the third embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station310moves from the supervisory area of the edge node306to that of the edge node307.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station310decides that its visiting area changes, and transmits its own IP address and the IP address of the new edge node to the old edge node (step S901). In the example ofFIG. 19, the mobile station310transmits its own IP address #10and the IP address #7of the new edge node307to the old edge node306. The transmission to the edge node306is carried out through the edge node307, repeater node304, gate node302and repeater node303, for example.

The old edge node creates a transfer table establishing the relationship between the IP address of the mobile station and the IP address of the new edge node (redirection edge node) (S902) so that when the old edge node thereafter receives data to which the IP address of the mobile station is added, it transmits (transfers) the data to the new edge node with adding the IP address of the new edge node to the data. In the example ofFIG. 19, when receiving the data to which the IP address #10of the mobile station310is added, the edge node306transmits the data to the edge node307with adding the IP address #7of the edge node307to the data.

Using the second handover control can reduce the data (packet) loss as compared with using the first handover control.

In the second handover control, however, there is a possibility of transmission delay or aggregation because the data is transferred from the first visiting edge node of the mobile station. Therefore, it is possible to update the table of the party edge node as in the first handover control at some opportunity.

As for the opportunity for update, it is analogous to that of the first embodiment in accordance with the present invention.

The update of the table of the party edge node is carried out by transmitting from the old edge node to the party edge node the IP address of the mobile station and the IP address of the new edge node. After transmitting the IP addresses, the old edge node releases its own transfer table and the like, which is preferably released after the old edge node receives the notification from the party edge node that the update of its table is completed, to prevent data (packet) loss.

Incidentally, when employing the method of accessing the location information server300every time the edge node receives a packet, it is unnecessary for the edge node to possess the table, and hence to update the table of the party edge node during the handover. In this case, the moving mobile station notifies the location information server300of its own IP address and the IP address of the new edge node so that the location information server300updates its own information in accordance with the IP addresses.

When handover takes place in the method in which the edge node updates its table by periodically accessing the location information server300, the table of the party edge node can be either updated in the same manner as the foregoing method, or not updated at all. When it is not updated, a packet loss can occur from the time of the handover to the next periodic update.

The fourth embodiment in accordance with the present invention also implements data transfer between mobile stations. The routing is carried out by the IP addresses of the mobile stations as in the second embodiment.

FIG. 21is a block diagram showing a configuration of a mobile communications network of the fourth embodiment in accordance with the present invention.

The mobile communications network of the present embodiment comprises a gate node402, repeater nodes403and404, and edge nodes405–408, but not a location information server400. The functions of the nodes are the same as those of their counterparts in the second embodiment.

The gate node402, repeater nodes403and404, and edge nodes405–408have their own IP addresses (#2, #3, #4, and #5–#8, respectively, in the present embodiment), and mobile stations409and410also have their own IP addresses (#9and #10in the present embodiment).

The gate node402and the repeater nodes403and404are a routing node for carrying out routing of the data in accordance with routing information.

FIG. 22is a flowchart illustrating part of a data transfer method between mobile stations in the mobile communications network of the fourth embodiment in accordance with the present invention.

Assume that a mobile station (409, for example) transmits data (IP packet) to the edge node (405, in this case) with adding the IP address (#10) of a party mobile station (410, for example) (step S1001).

Then, the edge node transmits the received data to the routing node (step S1002). In the example ofFIG. 21, since each edge node is connected to only one repeater node as in the third embodiment, the data is transmitted to the corresponding one of the repeater nodes.

The subsequent routing of the data is analogous to that of the second embodiment. For example, the data transmitted from the mobile station409to the mobile station410is transmitted through the edge node405, repeater node403and edge node406, and arrives at the mobile station410. The data transmission from the mobile station410to the mobile station409is carried out in a similar manner.

FIG. 23is a block diagram illustrating an example of the first handover control in the mobile communications network of the fourth embodiment in accordance with the present invention, andFIGS. 24A and 24Bare a flowchart illustrating the example of the first handover control in the mobile communications network of the fourth embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station410moves from the supervisory area of the edge node406to that of the edge node407.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station410decides that its visiting area changes, and transmits its own IP address to the edge node (S1101). In the example ofFIG. 23, the mobile station410transmits its own IP address to the edge node407.

The new edge node transmits the IP address of the moving mobile station to the higher level routing node (repeater node or gate node) (step S1102). Receiving the IP address of the mobile station, the routing node updates its own routing information about the (IP address of the) mobile station (or creates the information about the mobile station when there is no existing information) (step S1103), and transmits the IP address of the mobile station to the still higher level routing node. The processing is repeated up to the junction routing node of the transmission route to the old edge node and the transmission route to the new edge node (steps S1104and S1105).

In the example ofFIG. 23, the higher level routing node of the new edge node is the repeater node404, and the junction routing node of the transmission route to the old edge node (edge node406) and the transmission route to the new edge node (edge node407) is the gate node402. Accordingly, the repeater node404and gate node402update the routing information about the (IP address of the) mobile station410.

Arriving at the junction routing node, the processing proceeds to step S1106. At step S1106, a decision is made as to whether the current node is the higher level routing node of the old edge node or not, and if the decision result is positive, the processing is completed. Otherwise, the IP address of the mobile station is transmitted to the lower level routing node directing to the old edge node (step S1107). The lower level routing node updates its own routing information about the IP address of the mobile station (step S1108). Specifically, when it receives the data addressed to the mobile station, it updates its own routing information such that the data is transmitted to its higher level routing node. Incidentally, it is also possible to eliminate the routing information about the mobile station at step S1108, in which case, each routing node transmits the received data to its higher level routing node if there is no routing information about the (IP address of the) mobile station. After step S1108, the processing proceeds to step S1106, again.

FIG. 25is a block diagram illustrating an example of the second handover control in the mobile communications network of the fourth embodiment in accordance with the present invention, andFIG. 26is a flowchart illustrating the example of the second handover control in the mobile communications network of the fourth embodiment in accordance with the present invention. The handover control will be described by means of an example in which the mobile station410moves from the supervisory area of the edge node406to that of the edge node407.

Detecting that the broadcast IP address is different from the currently stored IP address, the mobile station410decides that its visiting area changes, and transmits its own IP address and the IP address of the new edge node to the old edge node (step S1201). In the example ofFIG. 25, the mobile station410transmits its own IP address #10and the IP address #7of the edge node407to the edge node406. The transmission to the old edge node406is carried out by placing the transmission route information into the routing information of each routing node, for the IP addresses of the individual edge nodes as illustrated inFIG. 25.

The old edge node creates a transfer table establishing the relationship between the IP address of the mobile station and the IP address of the new edge node (redirection edge node) (S1202) so that when it thereafter receives data to which the IP address of the mobile station is added, it transmits (transfers) the data to the new edge node with adding the IP address of the new edge node to the data. In the example ofFIG. 25, when receiving the data to which the IP address #10of the mobile station410is added, the old edge node406transmits the data to the new edge node407with adding the IP address #7of the edge node407to the data. The transmission to the new edge node407is carried out by placing the transmission route information about the IP address of the edge node into the routing information of each routing node as described above.

In the second handover control, however, there is a possibility of transmission delay or aggregation because the data is transferred from the first visiting edge node of the mobile station. Therefore, it is possible to update the table of the routing node as in the first handover control at some opportunity.

As for the opportunity for update, it is analogous to that of the first embodiment in accordance with the present invention.

The update of the routing information is carried out from the higher level routing node of the new edge node toward the junction node, and then from the junction node toward the higher level routing node of the old edge node as in the first handover control, for example. The release of the transfer table of the old edge node is preferably carried out after the update of the routing information of its higher level routing node is completed to prevent the data (packet) loss.

Supplements

A mobile communications network and a data delivery method can be implemented that have combined functions described in the foregoing embodiments (for example, those having the functions of the first and third embodiments).

Although the foregoing description separately explains the method of carrying out the routing in accordance with the IP address of the edge node (the first and third embodiments) and the method of carrying out the routing in accordance with the IP address of the mobile station (the second and fourth embodiments), a routing method combining the two methods is possible.

As described above, the present invention can implement the connectionless network and connectionless transfer with obviating the need for sending the call control signal in the data delivery in the mobile communications network.

In addition, it can prevent the network aggregation involved in delivering the same data to the users of the same group, thereby reducing the load of the data delivery server.

Moreover, it can implement control such as handover in such a connectionless network.