WO2010029798A1

WO2010029798A1 - Communication system, network node, mobile node, communication method, and program

Info

Publication number: WO2010029798A1
Application number: PCT/JP2009/060263
Authority: WO
Inventors: 潤粟野
Original assignee: 日本電気株式会社
Priority date: 2008-09-10
Filing date: 2009-06-04
Publication date: 2010-03-18
Also published as: JPWO2010029798A1

Abstract

A network node decides whether a mobile node is in a suppression mode for suppressing the communication amount or the power consumption amount. Unless the mobile node is in the suppression mode, the network node periodically transmits to the mobile node, setting information indicating a communication setting of a limited valid time with a cycle not greater than the limited valid time. The mobile node receives the setting information from the network node and maintains the communication setting indicated by the setting information during the suppression mode.

Description

Communication system, network node, mobile node, communication method, and program

The present invention relates to a technology that efficiently uses radio resources and saves power consumption of a mobile node.

In a mobile communication device such as a mobile phone (hereinafter referred to as “mobile node”), the battery capacity that the mobile node can be equipped with is limited due to weight and size restrictions. In addition, the bandwidth allocated to a node in wireless communication is generally smaller than that in wired communication. Furthermore, in a communication system in which a radio base station covers a large number of mobile nodes, such as a communication system that accommodates current mobile phones, each mobile node shares a limited band of the radio base station.

Thus, since the battery capacity and bandwidth of the mobile node are limited, the mobile node is provided with a function for suppressing its own power consumption and radio resources.

For example, in the standard defined by WiMAX (Worldwide Interoperability for Microwave Access) Forum, the mobile node shifts to the idle mode when communication is not performed for a while.

This idle mode is a state in which the mobile node can only receive a broadcast signal in the downlink direction (direction from the radio base station to the mobile node). In this state, the mobile node can suppress power consumption, and the radio base station can release the channel (radio resource) allocated to the mobile node.

The communication system disclosed in Patent Document 1 starts timing when the connection with the base station is suspended, stops when it detects an operating state, and sets a timer for entering the idle mode when it expires to the mobile unit. By providing the wireless resources, it is possible to suppress unnecessary release of radio resources.

In addition, the communication system described in Patent Document 2 prevents unnecessary power consumption by providing a timer that starts timing due to a radio link failure or the like and shifts to the idle mode when it expires.

JP 2004-159297 A JP 2004-166198 A

However, in the communication systems described in Patent Document 1 and Patent Document 2, unnecessary release of radio resources and power consumption may still not be sufficiently suppressed.

In recent years, there has been a trend of adopting IP technology in mobile communication systems, and since there are a large number of mobile terminals, IPv6 is often adopted. In this IPv6, the router transmits an RA (Router Advertisement) message to the mobile node in order to connect the mobile node to the network.

This RA message includes information indicating the validity period of default router communication settings, called Router Lifetime, and the mobile node that has received the RA message acquires the RA message source as the IP address of the default router. To do. Since this default router setting is valid only during the validity period, the router needs to periodically send an RA message to maintain the communication setting.

And when sharing the radio channel with multiple mobile nodes and adopting the point-to-point model, even when some mobile nodes are in idle mode, to prevent the expiration of communication settings, The radio base station must periodically transmit an RA message individually to all terminals including the node.

At this time, the mobile node in the idle mode needs to return from the idle mode in order to receive the RA, so that there is a problem that the use efficiency of radio resources is reduced and the power of the mobile node is also consumed excessively. In the communication system described in Patent Document 1 or 2, although there is a description regarding the transition to the idle mode, a means for maintaining the idle mode in the above situation is not considered.
A possible solution is to set Router Lifetime longer, but there is an upper limit. In addition, even if it is set long, regular transmission itself is not lost. Therefore, in a general mobile communication system such as a mobile phone, it is considered that a large number of mobile nodes are accommodated under a radio base station. This is not a fundamental solution.
An object of the present invention is to provide a technique for efficiently using radio resources of a communication system and reducing power consumption of a mobile node.

In order to achieve the above object, the communication system of the present invention determines whether or not a mobile node is in a suppression mode that suppresses the amount of communication or power consumption, and if the mobile node is not in the suppression mode, A network node that periodically transmits setting information indicating a communication setting with an expiration date to the mobile node at a period equal to or less than the expiration date, the setting information is received from the network node, and during the suppression mode, And a mobile node that maintains the communication setting indicated by the setting information.

The network node according to the present invention determines whether the mobile node is a suppression node that suppresses the amount of communication or power consumption, and the determination unit determines that the mobile node is not in the suppression mode. In this case, a transmission unit that periodically transmits setting information indicating communication settings with an expiration date to the mobile node at a period equal to or less than the expiration date.

The mobile node suppresses communication amount or power consumption by receiving means for receiving setting information indicating communication settings with an expiration date from the network node and the communication setting indicated by the setting information received by the receiving means. Setting means for maintaining during the suppression mode.

The communication method of the present invention determines whether or not the mobile node is in a suppression mode that suppresses the amount of communication or power consumption, and if the mobile node is not in the suppression mode, indicates a communication setting with an expiration date. A communication that periodically transmits setting information to the mobile node at a period equal to or less than the expiration date, the mobile node receives the setting information, and maintains the communication setting indicated by the setting information during the suppression mode. Is the method.

The program according to the first aspect of the present invention determines, in the computer, a determination procedure for determining whether or not the mobile node is a suppression node that suppresses the communication amount or power consumption, and the determination procedure determines that the mobile node is not in the suppression mode. If so, the program is for executing a transmission procedure for periodically transmitting setting information indicating communication settings with an expiration date to the mobile node at a period equal to or less than the expiration date.

A program according to a second aspect of the present invention provides a computer with a reception procedure for receiving setting information indicating a communication setting with an expiration date from a network node, and the communication setting indicated by the setting information received in the reception procedure. Is a program for executing a setting procedure for maintaining the communication mode or the power consumption amount during the suppression mode.

According to the present invention, since the communication setting is maintained while the mobile node is in the suppression mode, the network node does not have to allocate radio resources to the mobile node to periodically transmit the setting information during the suppression mode. As a result, radio resources can be used efficiently. Further, in the suppression mode, the mobile node does not have to return from the suppression mode for packet reception processing, so that power consumption can be reduced. *

1 is an overall view of a communication system according to a first embodiment. It is a block diagram which shows the structure of the forwarding node of 1st Embodiment. It is a block diagram which shows the structure of the mobile node of 1st Embodiment. It is a figure which shows the format of RA packet of 1st Embodiment. It is a flowchart which shows operation | movement of the forwarding node of 1st Embodiment. It is a flowchart which shows operation | movement of the mobile node of 1st Embodiment. It is a flowchart which shows the packet reception process of 1st Embodiment. It is a sequence diagram which shows the production | generation process of 1st Embodiment. It is a sequence diagram which shows operation | movement of the communication system of 1st Embodiment. It is a figure which shows the structure of the setting information of a modification. It is a flowchart which shows operation | movement of the forwarding node of 2nd Embodiment. It is a sequence diagram which shows the production | generation process of 2nd Embodiment. It is a sequence diagram which shows the production | generation process of 3rd Embodiment. It is a sequence diagram which shows the notification process of 3rd Embodiment. It is a sequence diagram which shows the production | generation process of 4th Embodiment. It is a flowchart which shows operation | movement of the forwarding node of 4th Embodiment.

(First embodiment)
A first embodiment for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall view showing a configuration of a communication system 1 according to the present invention. Referring to FIG. 1, the communication system 1 includes a mobility management server 10, a communication node 20, a transfer node 30 (network node), a radio base station 40, and a mobile node 50. The communication system 1 uses IPv6 or the like as a communication protocol. The core network N2 includes a mobility management server 10 and a communication node 20. The access network N1 includes a forwarding node 30 and a radio base station 40. The mobile node 50 is connected to the access network N1.

The mobility management server 10 holds the location information of the forwarding node 30 and transmits the packet addressed to the forwarding node 30 transmitted from the communication node 20 to the forwarding node 30 by a method such as tunneling. In addition, the mobility management server 10 transmits the packet addressed to the communication node 20 received via the transfer node 30 to the communication node 20.

The mobility management server 10 is, for example, a PDN-GW (Packet Data Network-Gateway) or S-GW (Serving-Gateway) in an EPC (Evolved Packet Core), which is a next generation network studied by 3GPP (Third Generation Partnership Project). ), Or WiMAX (Worldwide Interoperability Microwave Access) HA (Home Agent) in a communication system authenticated by the Forum.

The communication node 20 uses IP (Internet Protocol) as a communication protocol and has a function of communicating with other nodes including the mobile node 50.

The forwarding node 30 controls the mobile node 50 and has a router function. Specifically, the forwarding node 30 forwards the packet transmitted from the mobile node 50 to the mobility management server 10 and forwards the packet addressed to the mobile node 50 transmitted from the mobility management server 10 to the mobile node 50. In addition, the forwarding node 30 controls the radio base station 40.

For example, the forwarding node 30 is an ASN-GW (Access Service Network-Gateway) in a communication system authenticated by S-GW and WiMAX Forum in 3GPP.
FIG. 2 is a block diagram showing the configuration of the forwarding node 30. As shown in FIG. Referring to the figure, the forwarding node 30 includes a control unit 310 and a transmission / reception unit 320.
The control unit 310 monitors the communication state of the mobile node 50, and when the mobile node 50 detects that the mobile node 50 is not continuously communicating for a predetermined time or longer, the control unit 310 shifts the mobile node 50 to the idle mode. This idle mode is, for example, an idle mode defined in IEEE 802.16e-2005. When the forwarding node 30 receives a notification from the mobile node 50 that the mobile node 50 has shifted to the idle mode, the forwarding node 30 determines that the mobile node 50 has shifted to the idle mode.

When the transmitting / receiving unit 320 receives a packet addressed to the mobile node 50, the control unit 310 transmits the paging message to the mobile node 50, thereby returning the mobile node 50 from the idle mode. In addition, when receiving a notification from the mobile node 50 that the mobile node 50 has returned from the idle mode, the control unit 310 determines that the mobile node 50 has returned from the idle mode.

When the mobile node 50 is not in the idle mode, the transmission / reception unit 320 transmits a packet including an RA (Router Advertisement) message (hereinafter referred to as “RA packet”) to the mobile node 50 in order to validate the communication setting of the mobile node 50. Send to. For example, when an RS (Router Solicitation) message is received from the mobile node 50, the forwarding node 30 transmits an RA packet. The mobile node 50 acquires its own IP address based on the RA packet (first packet), and sets the node from which the RA packet is transmitted as a default router.

As long as the mobile node 50 is within a communicable range, the transmission / reception unit 320 periodically transmits RA packets to the mobile node 50. The reason why the RA packet is periodically transmitted is that the communication setting of the mobile node 50 expires when a predetermined valid period set in the RA packet elapses. The format of the RA packet will be described later.

While the mobile node 50 is in the idle mode, the transmission / reception unit 320 stops the periodic transmission of the RA message to the mobile node 50. Then, the control unit 310 releases all or a part of the radio resources allocated to the mobile node 50.

The radio base station 40 receives signals such as packets and control signals from the mobile node 50 and transmits them to the transfer node 30. Further, the radio base station 40 transmits the packet received from the transfer node 30 to the mobile node 50.

The mobile node 50 is a mobile communication device such as a mobile phone that uses IP as a communication protocol.

FIG. 3 is a block diagram showing the configuration of the mobile node 50. Referring to the figure, the mobile node 50 includes a transmission / reception unit 510, a storage unit 520, and a control unit 530.

The transmission / reception unit 510 transmits and receives packets and control signals to and from the transfer node 30 via the radio base station 40. The transmission / reception unit 510 includes a NIC (Network Interface Card) having a wireless function such as a WiMAX card or a wireless LAN (Local Area Network) card, and a driver that controls the NIC.

The storage unit 520 is a storage medium such as a RAM (Random Access Memory) or a flash memory. When the mobile node 50 receives an RA packet from the forwarding node 30, the mobile node 50 stores the packet in the storage unit 520 as an RA packet 5201. . Each time the mobile node 50 receives an RA packet, the mobile node 50 updates the RA packet 5201 stored in the storage unit 520 with the received packet.

FIG. 4 is a diagram showing the format of the RA packet. Referring to the figure, the RA packet 5201 includes a MAC (Media Access Control) header, an IP header, and an ICMP (Internet Control Message Protocol) header. The IP header stores the “source IP address” of the RA packet 5201, that is, the IP address of the forwarding node 30. The ICMP header includes a “type” field, a “router lifetime” field, a “prefix information” field, and the like. In the “type” field, a value indicating the type of packet is stored. In the case of an RA packet, a value “134” is stored. The “router lifetime” field stores information indicating a period during which the default router setting is valid. For example, on the transmission side, as the “router lifetime”, any value between 0 (seconds) and 9000 (seconds) is set as a 16-bit integer value.

3, the control unit 530 includes a generation unit 531 and a communication setting unit 532. The control unit 530 reads the value of the “type” field from the ICMP header of the packet received by the receiving unit 510. If the value is “134”, the control unit 530 determines that the received packet is an RA packet. Then, control unit 530 stores the received packet as RA packet 5201 in storage unit 520.

The generation unit 531 determines whether or not the mobile node 50 is in the idle mode. For example, when the operation by the user is not performed for a predetermined time or when the notification indicating the transition to the idle mode is received from the transfer node 30, the mobile node 50 transitions to the idle mode. Then, when a predetermined operation is performed by the user or when a paging message is received from the forwarding node 30, the mobile node 50 returns from the idle mode.

If the mobile node 50 is in the idle mode, the generation unit 531 reads the RA packet 5201 from the storage unit 520, periodically generates the RA packet 5311 from the read packet, and the OS (Operating System) L3 (Layer 3) Store in a stack (not shown).

The RA packet 5311 is a packet in which information (such as “prefix information”, “source address”, and “router lifetime”) regarding communication settings to be maintained is the same as the RA packet 5201.

The communication setting unit 532 reads information indicating “prefix information”, “source address”, “router lifetime”, and the like from the RA packet 5311 stored in the L3 stack, and sets its own address by “prefix information”. Set “source address” to the IP address of the default router, and enable the default router setting only for the “router lifetime” period.

In this way, while the mobile node 50 is in the idle mode, the mobile node 50 generates an RA packet by itself instead of the forwarding node 30, so that the forwarding node 30 is in the state where the mobile node 50 is in the idle mode. There is no need to periodically transmit RA packets to the mobile node 50 in order to maintain communication settings. For this reason, since the forwarding node 30 can release radio resources for RA packet transmission during the idle mode, the radio resources can be used efficiently. Further, since the mobile node 50 returns from the idle mode and does not need to perform the RA packet reception process, power consumption can be suppressed.

In particular, since processing of the IP layer and transport layer is usually implemented as part of the OS, it is difficult for anyone other than the vendor of the OS developer to change. If a method that does not change the IP stack is used, the communication system can easily improve the efficiency of radio resources and reduce the power consumption of the mobile node.

Next, operations of the forwarding node 30 and the mobile node 50 according to the present embodiment will be described with reference to FIGS. FIG. 5 is a flowchart showing the operation of the forwarding node 30. This operation is started when the transfer node 30 is activated or when a predetermined application is executed, and is repeatedly executed until the transfer node 30 is stopped or the predetermined application is terminated. Referring to the figure, forwarding node 30 determines whether mobile node 50 is in the idle mode (step S5).

If the mobile node 50 is not in the idle mode (step S5: NO), the forwarding node 30 has passed a predetermined period since receiving an RS packet (RS message) from the mobile node 50 or transmitting a previous RA packet. It is determined whether or not it has been done (step S7). This predetermined period is a period shorter than the “router lifetime” set in the RA packet.

If the predetermined period has elapsed (step S7: YES), the forwarding node 30 transmits an RA packet to the mobile node (step S9).

When the mobile node 50 is in the idle mode (step S5: YES), or when the predetermined period has not elapsed (step S7: NO), or after step S9, the forwarding node 30 ends the operation.

FIG. 6 is a flowchart showing the operation of the mobile node 50. This operation is started when the mobile node 50 receives a packet from the forwarding node 30. Referring to the figure, the transmission / reception unit 510 executes packet reception processing (step T1), the generation unit 531 executes generation processing (step T3), and the communication setting unit 532 uses the RA packet generated by the generation unit 531. 5311 is processed to set the address of the default router (step T5). After step T5, the mobile node 50 ends its operation.
FIG. 7 is a flowchart showing the packet reception process. Referring to the figure, when the transmission / reception unit 510 receives a packet from the forwarding node 30, the transmission / reception unit 510 reads the “type” number in the ICMP header of the packet to determine whether the received packet is an RA packet or not. (Step T11).
If the received packet is an RA packet (step T11: YES), the mobile node 50 stores the RA packet in the storage unit 520 (step T13).

If the received packet is not an RA packet (step T11: NO), or after step T13, the mobile node 50 ends the packet reception process.

FIG. 8 is a flowchart showing the generation process. Referring to the figure, the generation unit 531 determines whether or not the mobile node 50 is in the idle mode (step T31). If the mobile node 50 is in the idle mode (step T31: YES), the generation unit 531 determines whether or not a predetermined period has elapsed since the transition to the idle mode or the previous generation of the RA packet 5311 ( Step T33).

If the predetermined period has elapsed (step T33: YES), the generation unit 531 generates the RA packet 5311 based on the RA packet 5201 (step T35). Then, the generation unit 531 stores the RA packet in the L3 stack (step T37).

If the mobile node 50 is not in the idle mode (step T31: NO), if the predetermined period has not elapsed (step T33: NO), or after step T37, the generation unit 531 ends the generation process.

Subsequently, an example of the operation result of the communication system 1 will be described with reference to FIG. FIG. 2 is a sequence diagram showing the operation of the communication system 1. Referring to FIG. 8, if the registered mobile node 50 is not in the idle mode (step S5: NO), the forwarding node 30 periodically transmits an RA packet to the mobile node 50 (step S9). Further, the packet P1 addressed to the mobile node 50 received from the communication node 20 is transferred to the mobile node 50.

The mobile node 50 stores the RA packet in the storage unit 520 (step T13).

If the mobile node 50 is in the idle mode (step S5: YES), the forwarding node 30 stops the periodic transmission of RA packets. Then, in the idle mode state (step T31: YES), the mobile node 50 generates an RA packet 5311 (step T35) and maintains the communication settings (step T5).

When the mobile node 50 is in the idle mode, when the communication node 20 transmits the packet P2 addressed to the mobile node 50, the forwarding node 30 transmits the paging message to the mobile node 50, thereby moving the mobile node 50 from the idle mode. Return. Then, the forwarding node 30 forwards the packet P2 to the mobile node.

When the mobile node 50 returns from the idle mode, the mobile node 50 stops periodically generating RA packets. The forwarding node 30 periodically transmits RA packets to the mobile node 50 (step S9).

The communication system 1 may accommodate a plurality of transfer nodes 30, and one transfer node 30 may control a plurality of mobile nodes 50.
In the present embodiment, the forwarding node 50 is provided separately from the radio base station 40, but the radio base station 40 and the forwarding node 50 may be mounted on one device.

In the present embodiment, the communication system 1 uses IPv6 as a communication protocol. However, if the protocol requires periodic message transmission to maintain the communication setting of the terminal (50), the other protocol is used. May be.

In the present embodiment, the communication node 20 is configured to be connected to the core network N2, but may be configured to be connected to the access network N1.

In this embodiment, the idle mode in IEEE 802.16e-2005 is exemplified, but the present invention is not limited to this. The present invention can also be applied to other operation modes (suppression modes) that suppress communication volume or power consumption. For example, the suppression mode may include a sleep mode in IEEE 802.16e-2005 and a dormant mode defined in a communication system such as 3GPP in addition to the idle mode.

In this embodiment, the transfer node 30 and the radio base station 40 are separated from each other, but the radio base station 40 may have a function of the transfer node 30.

In the present embodiment, the mobile node 50 is configured to store setting information indicating the “router lifetime”, but the stored information may be setting information for validating the communication setting only during the valid period. . For example, the mobile node 50 may store the RA packet 5311 including other setting information such as “Valid lifetime” indicating the validity period of the address prefix and periodically generate the packet.

In the present embodiment, the mobile node 50 stores the RA packet as it is in the storage unit 520, but this configuration can be changed. For example, as shown in FIG. 10, information indicating “prefix information”, “source address”, “router lifetime”, and the like are read from the RA packet, and only the read information is stored in the storage unit 520 as setting information 5201a. It is good also as a structure.

In this embodiment, the mobile node 50 is configured to periodically generate RA packets, but this configuration can be changed. The packet to be generated is not limited to the RA packet as long as it is a packet that the forwarding node 30 needs to transmit periodically in order to validate the communication setting of the mobile node only for a predetermined valid period. For example, the mobile node 50 may periodically generate an AA (Agent Advertisement) packet.

As described above, according to the present embodiment, while the mobile node 50 is in the suppression mode, the mobile node 50 validates the communication setting based on the setting information stored by itself. 30 does not need to allocate radio resources to the mobile node 50 in order to periodically transmit the RA packet 5201 including the setting information. As a result, the communication system can efficiently use radio resources. In addition, since the mobile node 50 does not have to return from the suppression mode for packet reception processing in the suppression mode, power consumption can be reduced.

Further, since the mobile node 50 enables its own communication setting by periodically generating the RA packet 5311 at a predetermined period equal to or less than the effective period, communication in which the packet is stored in the IP stack and communication setting is performed. The present invention can be applied to the system with minimal changes.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. The configuration of the communication system of the present embodiment is the same as the configuration of the communication system of the first embodiment. However, the communication system of the present embodiment differs from that of the first embodiment in that the forwarding node 30 determines whether or not the control target node (50) is a node that performs communication settings in the idle mode. .

FIG. 11 is a flowchart showing the operation of the forwarding node 30 of this embodiment. Referring to the figure, the operation of the forwarding node 30 of the present embodiment is the same as the operation of the forwarding node 30 of the first embodiment, except that the forwarding node 30 further executes step S1.

The forwarding node 30 determines whether or not the mobile node 50 is a node that generates an RA packet (step S1). For example, the forwarding node 30 stores information for specifying a node that generates an RA packet in advance. Alternatively, the forwarding node 30 receives information for specifying a node that generates an RA packet from another node. Then, the forwarding node 30 determines whether or not the mobile node 50 is a node that generates an RA packet based on these pieces of information.

If the mobile node 50 is a node that generates an RA packet (step S1: YES), the forwarding node 30 determines whether or not the forwarding node 50 is in the idle mode (step S5).

If the mobile node 50 is not a node that generates an RA packet (step S1: NO), the forwarding node 30 determines whether or not a predetermined period has elapsed (step S7).

As described above, according to the present embodiment, the forwarding node 30 performs periodic transmission of RA packets when the mobile node 50 is a node that generates an RA packet and the mobile node 50 is in the idle mode. Since it stops, there is no possibility of stopping periodic transmission to a node that does not generate an RA packet. The communication system can also mix nodes that generate RA packets and nodes that do not.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS. The configuration of the communication system of the present embodiment is the same as the configuration of the communication system of the first embodiment. However, the communication system according to the present embodiment receives the fact that the periodic transmission of the RA packet is stopped from the forwarding node 30 and the mobile node 50 generates the RA packet 5311 only when the mobile node 50 shifts to the idle mode. Different from the first embodiment.

FIG. 12 is a flowchart showing the operation of the forwarding node 30 of this embodiment. Referring to the figure, the operation of the forwarding node 30 of this embodiment is the same as the operation of the forwarding node 30 of the first embodiment, except that the forwarding node 30 further executes steps S2 and S3.

The forwarding node 30 determines whether or not to decide to move the mobile node 50 to the idle mode (step S2).

For example, the forwarding node 30 monitors the communication state of the mobile node 50 and, when detecting that the mobile node does not transmit a packet for a predetermined time or more, determines that the mobile node 50 is shifted to the idle mode.
If it is determined to move the mobile node 50 to the idle mode (step S2: YES), the forwarding node 30 transmits a message (transmission stop message) to stop the periodic transmission of the RA packet to the mobile node 50. (Step S3).

If the mobile node 50 has not been determined to enter the idle mode (step S2: NO), or after step S3, the forwarding node 30 executes step S5.
FIG. 13 is a flowchart showing the generation processing of this embodiment. Referring to the figure, the generation process of the present embodiment is different from the generation process of the first embodiment in that step T30 is further executed.

The generation unit 531 determines whether a transmission stop message has been received from the transfer node 30 (step T30).

If the transmission stop message has been received (step T30: YES), the mobile node 50 executes step T31.

If the transmission stop message has not been received (step T30: NO), the generation unit 531 ends the generation process.

If the forwarding node 30 is a node that does not stop periodic transmission even in the idle mode, the mobile node 50 does not need to generate the RA packet 5311 itself. On the contrary, it is useless for the mobile node 50 to generate the RA packet 5311 even during regular transmission, which may cause malfunction.

However, as described above, according to the present embodiment, the mobile node 50 receives the message indicating that the periodic transmission is stopped, and starts generating the RA packet when the mobile node 50 shifts to the idle mode. Although the forwarding node 30 does not perform periodic transmission, it does not generate an RA packet. As a result, an increase in power consumption and malfunction due to unnecessary processing can be suppressed.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIGS. The configuration of the communication system of the present embodiment is the same as the configuration of the communication system of the first embodiment. However, the communication system according to the present embodiment differs from the first embodiment in that the mobile node 50 requests the transfer node 30 to stop the periodic transmission of RA packets.

FIG. 14 is a flowchart showing the generation processing of this embodiment. Referring to the figure, the generation process of the present embodiment is the first except that the mobile node 50 executes the notification process (step T32) and executes step T33 if the idle mode is set (step T31: YES). This is the same as the generation processing of the embodiment.

FIG. 15 is a flowchart showing the notification process. Referring to the figure, the mobile node 50 determines whether or not the forwarding node 30 has been notified of a message (stop request message) requesting to stop the periodic transmission of RA packets (step S321).

If the stop request message is not notified (step S321: NO), the mobile node 50 transmits a stop request message to the transfer node 30 (step S323). After step S323, the mobile node 50 ends the notification process.
FIG. 16 is a flowchart showing the operation of the forwarding node 30 of this embodiment. Referring to the figure, the operation of the forwarding node of this embodiment is the same as the operation of the forwarding node of the first embodiment except that step S4 is executed.

The forwarding node 30 determines whether a stop request message has been received from the mobile node 50 (step S4). If the stop request message has been received (step S4: YES), the forwarding node 30 executes step S5. If the stop request message has not been received (step S4: NO), the forwarding node 30 executes step S7.

As described above, according to the present embodiment, when the mobile node 50 requests to stop the RA packet and shifts to the idle mode, the forwarding node 30 stops the periodic transmission. For this reason, the forwarding node 30 stops the periodic transmission for the mobile node that does not generate the RA packet itself, and the communication setting of the mobile node does not expire.
It should be noted that all or part of the flowcharts shown in FIGS. 5 to 8 and FIGS. 11 to 15 can be realized by executing a computer program.
This application claims the benefit of priority based on Japanese Patent Application No. 2008-232251 filed on Sep. 10, 2008, the entire disclosure of which is incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Communication system 10 Communication node 20 Movement management server 30 Forwarding node 40 Wireless base station 50 Mobile node 510 Transmission / reception part 520 Storage part 530 Control part 531 Generation part 532 Communication setting part 5201, 5311 RA packet 5201a Setting information P1, P2 packet S1 ~ S9, T1 to T5, T11 to T13, T31 to T39, T321, T323 step

Claims

It is determined whether the mobile node is in the suppression mode that suppresses the communication amount or the power consumption amount. If the mobile node is not in the suppression mode, the setting information indicating the communication setting with an expiration date is displayed. A network node that periodically transmits to the mobile node in the following cycle:
A mobile node that receives the setting information from the network node and maintains the communication setting indicated by the setting information during the suppression mode;
A communication system.
The network node periodically transmits a packet including the setting information to the mobile node in the period when the mobile node is not in the suppression mode,
The mobile node holds the setting information included in the packet received from the network node, and transmits an internal packet that simulates the packet based on the held setting information during the suppression mode. The communication system according to claim 1, wherein the communication system is periodically generated within itself at a cycle shorter than the expiration date.
The network node controls the operation mode of the mobile node, and when the mobile node shifts to the suppression mode, a transmission stop message indicating that periodic transmission of the setting information is stopped is sent to the mobile node. Transmit, stop periodic transmission of the packet,
The communication system according to claim 1 or 2, wherein, when the mobile node receives the transmission stop message, the mobile node maintains the communication setting during the suppression mode.
The network node further determines whether the mobile node is a node that maintains the communication setting during the suppression mode, and the mobile node maintains the communication setting during the suppression mode The communication system according to any one of claims 1 to 3, wherein when the node is not a node or when the mobile node is not in the suppression mode, the setting information is periodically transmitted to the mobile node at the period.
When the mobile node transitions to the suppression mode, the mobile node transmits a stop request message requesting to stop the periodic transmission of the setting information to the network node,
The communication system according to claim 1, wherein the network node stops periodic transmission of the setting information when receiving the stop request message from the mobile node.
The communication system according to any one of claims 1 to 5, wherein the network node is a transfer node that transfers data transmitted and received between the mobile node and another node.
Determining means for determining whether or not the mobile node is a suppression node that suppresses the amount of communication or power consumption;
If the determination means determines that the mobile node is not in the suppression mode, transmission means for periodically transmitting setting information indicating a communication setting with an expiration date to the mobile node at a period equal to or less than the expiration date When,
A network node having
The determination means determines whether to move the mobile node to the suppression mode,
The transmission unit transmits a transmission stop message indicating that the periodic transmission of the setting information is stopped when the determination unit determines to shift the mobile node to the suppression mode, and The network node according to claim 7, wherein transmission is stopped.
The determination means further determines whether or not the mobile node is a node that maintains the communication setting during the suppression mode,
The transmitting means, when the determining means determines that the mobile node is not a node that maintains the communication settings during the suppression mode, or when the mobile node is not in the suppression mode, The network node according to claim 7 or 8, wherein the setting information is periodically transmitted to the mobile node in the cycle.
Receiving means for receiving a stop request message for requesting to stop the periodic transmission of the setting information from another node;
The network node according to claim 7, wherein the transmission unit stops the periodic transmission of the setting information when the stop request message is received by the reception unit.
The network node according to any one of claims 7 to 10, wherein the network node is a transfer node that transfers data transmitted and received between the mobile node and another node.
Receiving means for receiving setting information indicating communication settings with an expiration date from the network node;
Setting means for maintaining the communication setting indicated by the setting information received by the receiving means during a suppression mode for suppressing communication amount or power consumption;
A mobile node having
The receiving means receives a packet including the setting information;
A storage unit that holds the setting information included in the packet received by the reception unit;
The setting unit periodically generates an internal packet that simulates the packet based on the setting information held in the storage unit at a cycle shorter than the expiration date during the suppression mode. Item 13. The mobile node according to Item 12.
The receiving means further receives a transmission stop message indicating that periodic transmission of the setting information is stopped,
The mobile node according to claim 12 or 13, wherein the setting means maintains the communication setting during the suppression mode when the transmission stop message is received.
The movement according to any one of claims 12 to 14, further comprising a transmission unit that transmits a stop request message to the network node for requesting to stop the periodic transmission of the setting information when the mode is shifted to the suppression mode. node.
Determine whether the mobile node is in a suppression mode that suppresses the amount of communication or power consumption,
If the mobile node is not in the suppression mode, setting information indicating communication settings with an expiration date is periodically transmitted to the mobile node at a period equal to or less than the expiration date,
The mobile node receives the setting information,
A communication method for maintaining the communication setting indicated by the setting information during the suppression mode.
On the computer,
A determination procedure for determining whether or not the mobile node is a suppression node that suppresses the communication amount or the power consumption amount,
If it is determined in the determination procedure that it is not the suppression mode, a transmission procedure for periodically transmitting setting information indicating communication settings with an expiration date to the mobile node at a period equal to or less than the expiration date;
A program for running
On the computer,
A reception procedure for receiving setting information indicating a communication setting with an expiration date from a network node, and the communication setting indicated by the setting information received in the receiving procedure during a suppression mode for suppressing communication amount or power consumption. Configuration steps to maintain,
A program for running