JP2012169729A - Wireless system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless system in which a transmission opportunity is secured for an own device by suppressing data being relayed in the own device.SOLUTION: A communication device in a wireless system comprises a statistical information acquisition unit 104 and a control unit 103. The statistical information acquisition unit 104 periodically samples information such as a data transmission amount of an own device, transmission source and destination IP addresses of packets received by the own device, and a device usage rate at a time of data transmission, and monitors whether or not a prescribed traffic restriction condition is satisfied. When the traffic restriction condition is satisfied, the control unit 103 makes a message creation unit 1011 create and send a traffic restriction message for controlling to stop other devices to select the own device as a relay. Therefore, a transmission source of the traffic restriction message can secure a data transmission opportunity for the own device.

Description

  The present invention relates to a radio system related to radio autonomous network routing (ad hoc routing) between mobile terminals.

  Conventionally, an ad hoc network is known as a network in which wireless terminals are configured by wireless communication without going through a base station. In an ad hoc network, even when wireless terminals that communicate with each other cannot communicate directly, communication is possible by relaying other wireless terminals.

  FIG. 9 is a diagram showing an outline of an ad hoc network. Hereinafter, each wireless terminal is referred to as a node. For example, in FIG. 9, node A and node B exist in the communication area 1, and node B and node C exist in the communication area 2. Here, since node A and node C do not exist in the same communication area, data cannot be directly transmitted from node A to node C. However, in an ad hoc network, each node autonomously detects other nodes, autonomously performs route optimization, and constructs an ad hoc wireless network. Therefore, the node A can transmit data to the node C by relaying the node B existing in the same communication area as the node itself.

  Routing protocols in ad hoc networks include OLSR (Optimized Link State Routing) and AODV (Adhoc Ondemand Distance Vector). Here, an outline of OLSR will be described. OLSR is one of the mesh type (cotton link type) routing protocols studied by the IETF MANET WG (Internet Engineering Task Force Mobile Ad-hoc NETworks Working Group). OLSR is a Proactive type routing protocol that establishes a communication path in advance before a communication request is generated, so communication can be started immediately at any time.

  In OLSR, a communication path is determined before communication by exchanging packets between nodes in advance. Each node exchanges two control messages called mainly a Hello message and a TC (Topology Control) message between the nodes, and grasps information in the network to construct a route. OLSR packets are transmitted and received using UDP (User Datagram Protocol) port number 698. In OLSR, packets storing these control messages are broadcast (flooded) simultaneously by radio waves by each node.

  The Hello message is flooded to adjacent nodes that can communicate directly from each node. The Hello message is a route control message that is transmitted periodically for the purpose of distributing route information possessed by each node. Each node receives the Hello message, collects information on the peripheral nodes, and determines a logical connection (local link) with the peripheral nodes and a relay node called MPR (Multi Point Relay).

  FIG. 10 is a diagram showing a Hello message format. The Hello message contains an Originator IP Address that stores the address of the sender, a LinkCode that stores the LinkType that indicates the link status of the node, Willingness that indicates the level of positiveness that the local node relays, and the address of the adjacent node There is a Neighbor Hood node Address where is stored. There are UNSPEC_LINK (link status unknown), ASYM_LINK (one-way link), SYM_LINK (bidirectional link), and LOST_LINK (disconnected link) in LinkCode LinkType. In addition, Willingness includes WILL_NEVER (not selected by MPR), WILL_LOW (MPR selection frequency is low), WILL_DEFAULT (normal setting value), WILL_HIGH (MPR selection frequency is high), and WILL_ALWAYS (always selected by MPR). Take the values '0', '1', '3', '5' and '7', respectively. Each node is more likely to be selected as an MPR as the Willingness value is higher.

  The MPR is a node that transfers (relays) a packet. Each node can know a node group that is one hop ahead and a node group that is two hops ahead by receiving the Hello message. Each node selects a part of the node group 1 hop ahead as the MPR so that all nodes 2 hops ahead can receive the transferred control message.

  FIG. 11 is a diagram illustrating an outline of logical connection by a Hello message, (a) is a diagram illustrating a state in which logical connection is performed by a Hello message, and (b) is a diagram illustrating a link constructed by the Hello message. It is. Here, a state in which a route is built around the Hello message flooded by the node B will be described, but the same applies to other nodes such as the node A and the node C.

  Specifically, referring to FIG. 11A, a state in which a logical connection is made by a Hello message will be described. First, in step S101, as an initial stage in which a Hello message is transmitted and received, the Node B floods the adjacent node with a Hello message that stores the address of the own node in order to appeal the presence of the own node. At this time, LINKTYPE is transmitted as UNSPEC_LINK (link status unknown).

  In step S102, the node A recognizes the source node B as an adjacent node of the one-way link and adds it to the route information held by the node because the received Hello message does not include the address of the node itself. To do. In step S103, the node A floods the Hello message storing the address of the adjacent node B with LINKTYPE as ASYM_LINK (one-way link) in the Hello message transmission cycle. The same applies to node C.

  In step S104, the node B can confirm that the node A has received the UNSPEC_LINK Hello message transmitted by the node A because the received Hello message includes the address of the node as ASYM_LINK. Recognize that a bidirectional link has been established between them, and add it to the route information held by the node itself. Similarly, the node B recognizes that a bidirectional link has been established with the node C based on the Hello message received from the node C, and adds it to the route information. Thereafter, in step S105, the node B floods the Hello message storing the addresses of the nodes A and C with LINKTYPE as SYM_LINK (bidirectional link) in the next Hello message transmission cycle.

  In step S106, the node A recognizes that a bidirectional link has been established between the self node and the node B because the received Hello message includes the address of the self node as SYM_LINK. Recognizing that node C in which a bidirectional link is established with B is two hops away, it is added to the route information. Therefore, in step S107, the node A stores the address of the node B with LINKTYPE as SYM_LINK (bidirectional link) in the next Hello message transmission cycle, sets the LINKTYPE as MPRLINK, and selects the node B as MPR. The Hello message that stores the effect is flooded. The same applies to node C.

  As a result, as shown in FIG. 11B, node B performs logical connection with each of node A and node C by transmitting and receiving Hello messages to and from node A and node C, thereby establishing a mesh link. Is done. Further, the node B recognizes that it has been selected as the MPR of the node A and the node C by the Hello message, and plays a role of relaying a message transmitted from the node A or the node C. In the following, nodes that are MPRs are indicated by hatching.

  When all the nodes perform the above flow, a logical connection is made between each node by a Hello message, and a node to be an MPR is determined.

  When the node is selected by the MPR, the node periodically floods the TC message to notify the configuration (topology) of the entire network. The TC message is a control message transmitted only by the node selected by the MPR. In the Hello message, since transfer by MPR is not performed, transmission / reception is performed between adjacent nodes. However, in the TC message, transfer by MPR is performed, and thus all nodes have topology information of the entire network in common.

  FIG. 12 is a diagram showing a TC message format. The TC message includes an Advertised Neighbor node Address that stores the address of an MPR selector set that is a set of nodes that have selected the node as an MPR. When the MPR receives a control message that requires notification to all nodes, such as a TC message, from the node corresponding to the Advertised Neighbor node Address, the MPR performs flooding and transfer. On the other hand, the MPR only receives a control message received from a node that does not correspond to the Advertised Neighbor node Address, and does not perform flooding.

  FIG. 13 is a diagram showing an outline of route determination by the TC message. In FIG. 13, node B is selected from nodes A, D, E to MPR, node C is selected from nodes A, F to MPR, and node E is selected from nodes B, C, D, F, G to MPR. Node F is selected as MPR from nodes C, E, and I. Nodes B, C, E, and F, which are MPR sets, flood their own topology information with TC messages.

  For example, node C includes the address of its own node and the address of each node (MPR selector set) that has selected itself as an MPR in the TC message, and uses [C ← A] and [C ← F] as topology information. Is flooded with a TC message. Each node acquires topology information based on the flooded TC message, and transfers the TC message if the node is MPR. As described above, the topology information is flooded to all nodes by each MPR, so that each node is [B ← A], [B ← D], [B ← E], [ C ← A], [C ← F], [E ← B], [E ← C], [E ← D], [E ← F], [E ← G], [F ← C], [F ← E] and [F ← I] can be held.

  When each node obtains common topology information in the network by a TC message, each node calculates the shortest route to reach each node. Each node knows the last one-hop route from the TC message to the target node. For example, in the route setting from the node D to the node I, first, information on the node logically connected to the node I is obtained. [F⇔I] is extracted as Since node D has selected node E as the MPR to be transferred to node F, it extracts [E⇔F] and finally calculates the route with [D⇔E⇔F⇔I] Based on this information, the route from node D to node I is registered in the route information.

  Thereby, the route is determined between the nodes by the TC message. Note that the TC message has information indicating the life in terms of MsgTTL, and the value of MsgTTL is decreased by 1 every time it is transferred by the MPR, so that there is no infinite loop.

  In this way, each node can freely communicate with all nodes participating in the OLSR mesh network using the Hello message and the TC message.

  The OLSR has a control message called an HNA (Host and Network Association) message. FIG. 14 is a diagram showing an HNA message format. The HNA message is provided with a Network Address for storing the network address to which the node belongs, NetMask indicating its netmask, and the like. Similar to the TC message, the HNA message is a message notified to all nodes by the MPR.

  FIG. 15 is a diagram illustrating how the HNA message is flooded. Here, an internet gateway that is wired to the Internet is included in the mesh network. For example, the address of the Internet gateway connected to the wired network is registered in advance in the node G, and the HNA message is flooded from the node G. Thereby, each node can recognize that there is an Internet gateway that can be connected to the external network beyond the node G by the flooded HNA message. Therefore, for example, the node A can be connected to the Internet via the nodes B, E, and G.

  In ad hoc networks, a CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method is employed so that each node transmits data at the same time so that there is no collision between the data (for example, Patent Document 1). reference).

JP 2005-012275 A

  As described above, in an ad hoc network, control messages such as Hello messages and TC messages are flooded to construct a communication path, and by limiting the nodes that transfer control messages to MPR, The load is reduced.

  However, since the node selected as the MPR transmits relay data from other nodes, there is a possibility that the transmission of data of the own node may be hindered. This is a particularly serious problem for a node selected as an MPR from a plurality of nodes.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of suppressing data relayed by the own device and ensuring a transmission opportunity of the data of the own device.

The communication system of the present invention is a wireless system including a plurality of wireless devices that perform wireless communication, and includes a second wireless device that relays data transmitted from the first wireless device to a third wireless device, The second radio apparatus selects the own apparatus as a relay apparatus when determining whether the predetermined suppression condition is met based on the traffic information of the own apparatus and when the predetermined suppression condition is met Relay control means for stopping the relay process by controlling the plurality of wireless devices to stop selecting the relay device is provided.
Further, the relay control unit reduces the selectivity selected by the plurality of wireless devices as the relay device when the number of the plurality of wireless devices having the device as the relay device is equal to or greater than a predetermined ratio. May be.

  ADVANTAGE OF THE INVENTION According to this invention, the data transmission opportunity of an own apparatus can be suppressed and the transmission opportunity of the data of an own apparatus can be ensured.

It is a figure which shows the network structure of the communication system of embodiment which concerns on this invention. It is a functional block diagram which shows the structure of the communication apparatus of embodiment which concerns on this invention. It is an example of the table which shows the traffic suppression conditions of embodiment which concerns on this invention. It is a figure which shows the outline | summary of the relay cancellation process of embodiment which concerns on this invention. It is a figure which shows the traffic suppression message format of embodiment which concerns on this invention. It is a flowchart which shows the flow of the process which transmits the traffic suppression message of embodiment which concerns on this invention. It is a flowchart which shows the flow of a process when the traffic suppression message of embodiment which concerns on this invention is received. It is a flowchart which shows the flow of a process when the traffic suppression message of embodiment which concerns on this invention is received. It is a figure which shows the outline | summary of the conventional ad hoc network. It is a figure which shows the conventional Hello message format. FIG. 11 is a diagram showing an outline of logical connection by a Hello message, (a) is a diagram showing a state in which logical connection is made by a Hello message, and (b) is a link constructed by the Hello message. FIG. It is a figure which shows the conventional TC message format. It is a figure which shows the outline | summary of the route determination by the conventional TC message. It is a figure which shows the conventional HNA message format. It is a figure which shows a mode that the conventional HNA message is flooded.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an example of a network configuration in the communication system of the present embodiment. In FIG. 1, a solid line indicates a wired link connected by wire, and a dotted line indicates a wireless link connected wirelessly. The communication system does not distinguish between terminals # 1 to # 6 (hereinafter referred to as terminal Y when terminals # 1 to # 6 are not distinguished) and communication apparatuses # 1 to # 5 (hereinafter referred to as communication apparatuses # 1 to # 5). In this case, the communication device X). The terminal Y and the communication device X are connected by wire, and the communication device X is connected wirelessly. In addition, a wireless autonomous network such as an ad hoc network is constructed by a plurality of communication devices X.

The configuration of the communication device X will be described with reference to FIG.
The communication device X includes a wired interface (EthernetPHY 401) connected to the wired link and a wireless interface (WirelessNetworkPHY 403) connected to the wireless link, and relays data input from the wired link or the wireless link.

  In the Ethernet PHY 401 in the L1 layer (physical layer), an electrical signal input from the terminal Y via the Ethernet-based wired link is converted into a frame and passed to the Ethernet MAC 400. The Ethernet PHY 401 converts the frame passed from the Ethernet MAC 400 into an electrical signal and sends it to the wired link. Similarly, the Wireless Network PHY 403 converts a radio signal input from another communication device X via a radio link into a frame and passes the frame to the Wireless MAC 402. Also, the WirelessNetworkPHY 403 converts the frame passed from the WirelessMAC 402 into a radio signal and sends it to the radio link.

  In the Ethernet MAC 400 in the L2 layer (MAC layer), the frame is converted into an IP packet and passed to the L3 layer (network layer). Also, the IP packet passed from the L3 layer is converted into a frame and passed to the Ethernet PHY 401. Similarly, WirelessMAC 402 converts the frame into an IP packet and passes it to the L3 layer (network layer). Also, the IP packet passed from the L3 layer is converted into a frame and passed to the WirelessNetworkPHY 403.

  In the L3 layer (network layer), the routing table 300 is referred to for the destination IP address extracted from the header of the IP packet, and the data extracted from the IP packet is processed in the upper layer if it is addressed to its own device. If the IP packet is not addressed to the own device, the packet is transferred to the lower layer for processing to the transfer destination node based on the routing table 300 and processed.

  In the routing table 300, route information is registered. Specifically, in the routing table 300, a destination IP address, a network and a netmask, a transfer destination IP address, a metric that is a measure of a route, an output interface, and the like are registered. The output interface registered in the routing table 300 may be a wired interface or a wireless interface. In addition, the route information referred to and matched in the routing table 300 in the transmission / reception of the IP packet is stored in the routing table cache 3001 which is a temporary storage area. In the L3 layer, first, it is searched whether the target route is registered in the routing table cache 3001. When the target route is not registered in the routing table cache 3001, the routing table 300 is referred to.

  In the L4 layer (transport layer), a plurality of filter packet queues 200 are arranged, and data is sent to each filter packet queue 200 according to the priority of transmission data passed from an upper layer or received data passed from a lower layer. Stored.

  In an upper layer above the L5 layer, a network module 100 that implements an IGP (Interior Gateway Protocol) and an ad hoc routing protocol is arranged. The network module 100 includes a control message generation unit 101, a control message transmission unit 102, a control unit 103, a statistical information acquisition unit 104, a filter / queue processing unit 105, a routing information base 106, a traffic control notification analysis unit 107, and a control message reception. Part 108 is arranged.

  When the data passed from the lower layer is a traffic suppression message described later, the control message receiving unit 108 passes the traffic suppression message to the traffic control notification analysis unit 107 and passes other control messages and data to the control unit 103.

  The control unit 103 stores route information and the like in the routing information base 106 based on a control message (such as a Hello message or a TC message) acquired from the control message receiving unit 108. Further, the control unit 103 registers route information in the routing table 300 based on information stored in the routing information base 106. When the control unit 103 stores the information in the routing information base 106, the control message generation unit extracts information necessary for transmission by the control message from the routing information base 106 according to a preset transmission interval of the control message. 101.

  The control message generator 101 generates a control message based on the information passed from the controller 103 and passes it to the control message transmitter 102. The control message transmission unit 102 passes the control message to the lower layer to perform transmission processing.

  The statistical information acquisition unit 104 acquires the traffic information of the own device and monitors the traffic volume in the wired section and the wireless section. Specifically, the statistical information acquisition unit 104 outputs, as traffic information, information on the number of transmission / reception packets and transmission / reception data size by the wired interface and the wireless interface, route information stored in the routing table cache 3001, and output to the wireless interface. The QoS (Quality Of Service) parameter of the IP packet to be transmitted and the usage rate of a device such as a CPU at the time of data transmission are periodically sampled. Based on the acquired traffic information, the statistical information acquisition unit 104 uses the bandwidth usage (or time and frequency required for data transmission) of the own node and the bandwidth usage (or time required for data transmission of other nodes) (or Statistics such as time and frequency required for data transmission) and QoS parameter distribution are collected and accumulated in a statistical information database (not shown). Then, the statistical information acquisition unit 104 monitors whether the traffic information obtained from the statistics meets a preset traffic suppression condition.

  FIG. 3 is an example of a table showing traffic suppression conditions. This table may be arranged at a location accessible by the statistical information acquisition unit 104. Here, three items of (1) bandwidth usage, (2) CPU usage rate, and (3) own node QoS are set as traffic suppression conditions. If any of these items is met, “traffic suppression processing” or “ "Relay cancellation processing" is executed.

  “Traffic suppression processing” is as follows: (1) When the transmission / reception packet of the node is an average of 1000 packets / sec or more for the bandwidth usage, (2) For the CPU usage, the usage rate in data transmission is 30% or more. In this case, (3) the local node QoS is executed when any one of the cases where the packet of AC_VI (priority) or more is 30% or more is applicable. In “traffic suppression processing”, packets whose QoS is AC_BE (normal) or less are suppressed.

  “Relay cancellation processing” (1) When the transmission / reception packet of the own node is 4000 packet / sec or more on average for the bandwidth usage, (2) The usage rate in data transmission is 50% or more for the CPU usage rate In this case, (3) For the local node QoS, it is executed when any one of the cases where the AC_VO (highest priority) packet is 40% or more is applicable. In the “relay cancellation process”, the relay process is canceled.

  Note that the item value and the number of items of this traffic suppression condition can be set as appropriate. For example, the statistical information acquisition unit 104 may periodically sample the remaining power of its own device, and perform “traffic suppression processing” or “relay cancellation processing” according to a predetermined remaining power value. . In addition, the processing when the traffic restriction condition is met can be set as appropriate.

  Returning to FIG. 2, if the statistical information acquisition unit 104 determines that the traffic suppression condition of the “relay cancellation process” is met, the statistical information acquisition unit 104 notifies the control unit 103 to that effect. In response to this notification, the control unit 103 causes the control message generation unit 101 to generate a Hello message with LINKTYPE set to LOST_LINK in order to disconnect the logical connection to the node that is currently performing the logical connection, and the control message transmission unit 102 To send via. In addition, the control unit 103 causes the control message generation unit 101 to change the Willingness (selectivity as a relay node) in the Hello message to a value smaller than the previously set value. The Hello message with reduced Willingness may be transmitted at the next transmission interval of the Hello message with LINKTYPE set to LOST_LINK.

  FIG. 4 is a diagram showing an outline of the “relay cancellation process”. Here, the flow of processing between the communication apparatuses # 1, # 2, and # 3 shown in FIG. 1 will be described as an example. Communication device # 2 is the MPR of communication device # 1 and communication device # 3. Here, it is assumed that the traffic of the communication device # 2 is congested and satisfies the traffic suppression condition, and the “relay cancellation process” is performed.

  First, in step S201, the communication apparatus # 2 floods a Hello message with LINKTYPE set to LOST_LINK. At this time, the communication device # 2 disconnects the links with all the nodes to which the own device is linked. In step S202, the communication device # 1 and the communication device # 3 that have received the Hello message disconnect the link to the communication device # 2. Next, in step S203, the communication device # 2 sets the MPR selectivity (Willingness) to '0' (WILL_NEVER) and sets the LINKTYPE to ASYM_LINK (one-way link) at the next Hello message transmission interval. Send a Hello message that contains the address of.

  In step S204, the communication device # 1 and the communication device # 3 that have received this Hello message store the IP address of their own device as ASYM_LINK in the Hello message, and therefore between the communication device # 2 and the own device. Recognizes that a bidirectional link has been established and sends a Hello message with LINK_TYPE set to SYM_LINK. In step S205, the communication device # 2 recognizes that a bidirectional link has been established with the communication device # 1, and transmits a Hello message with LINK_TYPE set to SIM_LINK at the next Hello message transmission interval. Similarly, the communication device # 2 transmits a Hello message with LINK_TYPE set to SIM_LINK to the communication device # 3. At this time, since the Hello message transmitted from the communication device # 2 is set to “0” for all Willingness except for the Hello message in step S201 transmitted to disconnect the link first, the communication device # 2 The MPR is not selected from the adjacent node. That is, the communication device # 2 can secure a band (opportunity) for transmitting data of the own device by canceling the relay process and giving up the role as the MPR.

  In step S206, when the communication device # 2 detects that the traffic congestion of the own device has eased and no longer satisfies the traffic suppression condition, the communication device # 2 sets the Willingness to the value before the “relay cancellation processing” is performed. Flood a Hello message. Thereby, the communication device # 1 and the communication device # 3 can select the communication device # 2 as the MPR again. In addition, adjacent nodes such as the communication device # 1 and the communication device # 3 select a new MPR and establish an alternative route that bypasses the communication device # 2 when the link is disconnected by the communication device # 2. .

  Note that, even when the “relay cancellation process” is performed, the control unit 103 holds the route registered in the routing table 300 held before the relay process is canceled as it is. Then, the control unit 103 uses the filter / queue processing unit 105 to filter the IP packet on the wired link side with the destination IP address and the transmission source IP address, and performs transmission / reception processing on only the IP packet on the wired link side via the wired interface. Let it be done. That is, in the “relay cancellation process”, the relay process on the wireless link side is stopped, but the relay process on the wired link side is continued.

  Returning to FIG. 2, if the statistical information acquisition unit 104 determines that the traffic suppression condition corresponding to the “traffic suppression process” is satisfied as a result of the monitoring, the statistical information acquisition unit 104 notifies the control unit 103 accordingly. With this notification, the control unit 103 causes the suppression message generation unit 1011 included in the control message generation unit 101 to generate a predetermined traffic suppression message.

  FIG. 5 is a diagram illustrating a traffic suppression message format. The traffic suppression message is composed of a message header part and a message payload part. The message header is a format common to OLSR. The message payload part includes a message interval indicating the message transmission interval, a QoS parameter indicating the QoS value, a traffic control timer indicating the time for suppressing the number of packets to be transmitted, and a node for which the priority is set low. There are a low priority host IP address indicating an IP address and a high priority host IP address indicating an IP address of a node whose priority is set high.

  Returning to FIG. 2, when the suppression message generation unit 1011 generates a traffic suppression message, it passes the control message transmission unit 102 to the control message transmission unit 102. The control message transmission unit 102 transmits a suppression message simultaneously when transmitting a control message such as a Hello message or a TC message via the lower layer.

  In addition to the traffic suppression conditions set in advance, the user may be able to set arbitrary traffic suppression conditions. In this case, it is assumed that the user can set the QoS to be suppressed and the IP address specified in the Low Priority Host IP Address or / and the High Priority Host IP Address as a traffic control request in the communication device X. In addition, the user can cancel the setting by the traffic control request by setting the traffic control cancellation request to the communication device X.

  Further, when receiving the traffic suppression message via the lower layer, the control message receiving unit 108 passes the traffic suppression message to the traffic control notification analyzing unit 107.

  The traffic control notification analysis unit 107 analyzes the traffic suppression message acquired from the control message reception unit 108 and notifies the control unit 103 of the traffic suppression content. The control unit 103 controls, for example, the filter / queue processing unit 105 so as to filter IP packets that are equal to or lower than the QoS parameter included in the traffic suppression message according to the notified traffic suppression content. The IP packet is inserted into the filter packet queue 200. The IP packet inserted into the filter packet queue 200 is sent out and relayed after being stored in the filter packet queue 200 for a predetermined time.

  Specifically, the flow of transmission processing when the communication device X transmits a traffic suppression message will be described with reference to FIG.

  First, in step A100, the communication device X determines whether the traffic information obtained from the statistics meets the suppression condition. If it is determined in step A100 that the communication device X does not satisfy the suppression condition (NO in step A100), the communication device X returns to step A100. On the other hand, if it is determined in step A100 that the communication device X satisfies the suppression condition (YES in step A100), transmission of data transmitted (relayed) by the own device with reference to the routing table cache 3001 in step A110. Check the source IP address and the destination IP address.

  In step A120, the communication apparatus X determines whether there is an IP address that occupies 50% or more in the routing table cache 3001. If it is determined in step A120 that the communication device X does not exist (NO in step A120), the process proceeds to step A150.

  On the other hand, if it is determined in step A120 that the communication device X is present (YES in step A120), it is determined in step A130 whether the IP is an IP address on the wired link side or an IP address on the wireless link side. If the communication device X determines in step A130 that the IP address is on the radio link side, in step A140, the communication device X adds the IP address to the Low Priority Host IP Address of the traffic suppression message, and proceeds to step A150. On the other hand, if the communication device X determines in step A130 that the IP address is on the wired link side, it proceeds to step A150.

  In Step A150, the communication device X sets the suppression target QoS of the traffic suppression condition in the QoS Parameter of the traffic suppression message. In step A160, the communication device X determines whether there is a traffic control request from the user. If it is determined in step A160 that there is no traffic control request (NO in step A160), the communication apparatus X proceeds to step A190.

  On the other hand, if it is determined in step A160 that there is a traffic control request (YES in step A160), the communication device X changes the suppression target QoS to the QoS parameter requested by the user in step A170. In step A180, the communication device X adds the IP address requested by the user to the Low Priority Host IP Address or High Priority Host IP Address of the traffic suppression message, and proceeds to step A190.

  In step A190, the communication device X transmits (floods) a traffic suppression message in which the QoS parameter, Low Priority Host IP Address, or High Priority Host IP Address is set. Subsequently, in step A200, the communication device X determines whether the traffic suppression condition is satisfied.

  If it is determined in step A200 that the communication device X does not satisfy the traffic suppression condition (NO in step A200), it is determined in step A210 whether there is a traffic control release request from the user. If it is determined in step A210 that there is a traffic control release request from the user (YES in step A210), the communication device X ends this process. On the other hand, if it is determined in step A210 that there is no traffic control release request from the user (NO in step A210), the communication apparatus X proceeds to step A220. If the communication device X determines in step A200 that the traffic suppression processing condition is met (YES in step A200), the process proceeds to step A220.

  In step A220, it is determined whether a time equal to or longer than a predetermined transmission interval has elapsed. If it is determined in step A220 that the time has elapsed (YES in step A220), the communication device X returns to step S190 and transmits a traffic suppression message again. On the other hand, if it is determined in step A220 that the time has not elapsed (NO in step A200), the communication device X returns to step A200 and determines again whether the suppression condition is satisfied.

  Through the above processing, the communication device X can generate a traffic suppression message and notify other communication devices X to suppress traffic to the own device when the traffic state of the communication device X satisfies the suppression condition. it can.

  Next, the flow of processing when the communication device X receives a traffic suppression message will be described with reference to FIG.

  First, in step B100, the communication device X determines whether a traffic suppression message has been received. If it is determined in step B100 that the communication apparatus X has not received (NO in step B100), step B100 is repeated. On the other hand, when it is determined in step B100 that the communication device X has received the traffic suppression message (YES in step B100), in step B110, “Traffic Control Timer” and “Low Priority Host IP Address” are determined from the traffic suppression message. Extract “High Priority Host IP Address” and “QoS Parameter”.

  In step B <b> 120, the communication apparatus X sets a low priority node filter queue for filtering packets whose “Low Priority Host IP Address” is a source IP address or a destination IP address in the filter packet queue 200. In step B <b> 130, the communication apparatus X sets a QoS filter queue for filtering IP packets whose ToS (Type Of Service) value of the IP header is “QoS Parameter” or less in the filter packet queue 200. In step B140, the communication device X performs filter setting (mangle) for rewriting the ToS value of the IP packet of “High Priority Host IP Address” to the maximum value OxE. As a result, the communication device X designated as “High Priority Host IP Address” by the communication device X that is the transmission source of the traffic suppression message has the ToS value of the IP packet to be transmitted as the maximum value OxE, and has the highest priority at the relay node. Communication bandwidth (communication opportunity) is guaranteed.

  Next, in step B150, the communication device X determines whether the message maintenance time (invalid time) of the message header portion in the traffic suppression message has elapsed. If it is determined in step B150 that the message maintenance time has elapsed (YES in step B150), the communication device X cancels the setting of the filter queue set in steps B120 and B130 in step B160, and ends this processing. To do. At this time, if a packet has already been inserted into each filter queue, it is appropriately processed by a flow (not shown) different from this processing.

  On the other hand, if it is determined in step B150 that the message maintenance time has not elapsed (NO in step B150), the communication device X determines in step B170 whether a packet has been received from the wireless side. If the communication device X determines in step B170 that it has not received (NO in step B170), it returns to step 150.

  If it is determined in step B170 that the communication device X has received a packet from the wireless side (YES in step B170), the source IP address or the destination IP address of the received packet is “Low Priority Host IP Address” in step B180. Is determined. If it is determined in step B180 that the communication device X corresponds to “Low Priority Host IP Address” (YES in step B180), the communication device X enqueues the packet in the Low Priority Node filter queue in step B190, and will be described later [1. ].

  On the other hand, if it is determined in step B180 that the communication device X does not correspond to “Low Priority Host IP Address” (NO in step B180), whether the ToS value of the received packet is equal to or less than “QoS Parameter” in step B200. judge. If the communication device X determines in step B200 that the ToS value is equal to or less than “QoS Parameter” (YES in step B200), the communication device X enqueues the packet in the QoS filter queue in step B220 and Proceed to the flow. On the other hand, if it is determined in step B200 that the ToS value is not equal to or less than “QoS Parameter” (NO in step B200), the communication apparatus X performs relay processing in step B210 and returns to step B150. That is, the IP packet relayed in step B210 does not frequently pass through the communication device X that is the transmission source of the traffic suppression message, and is limited to a packet having a QoS of a predetermined value or more.

  Next, the flow [1] will be described with reference to FIG.

  In step B230, the communication device X determines whether its own device is currently undergoing relay processing. If the communication device X determines in step B230 that relay processing is being performed (YES in step B230), the communication device X returns to step B230. On the other hand, if the communication device X determines in step B230 that the device itself is not performing relay processing (NO in step B230), it determines in step B240 whether a packet has already been inserted in the QoS filter queue. That is, the communication device X determines whether at least two packets are inserted in the QoS filter queue. If it is determined in step B240 that the packet has already been inserted (YES in step B240), in step B250, the communication device X dequeues the packet from the QoS filter queue and performs relay processing. Return to B150.

  On the other hand, if the communication device X determines in step B240 that no packet has already been inserted in the QoS filter queue (NO in step B240), whether or not the packet has already been inserted in the Low Priority Node filter queue in step B260. judge. That is, the communication device X determines whether at least two packets are inserted in the Low Priority Node filter queue. If it is determined in step B260 that no packet is inserted in the Low Priority Node filter queue (NO in step B260), the communication apparatus X returns to step B150 in FIG.

  On the other hand, if it is determined in step B260 that the packet has already been inserted into the Low Priority Node filter queue (YES in step B260), in step B270, a time longer than the “Traffic Control Timer” value has elapsed. To determine. This may be determined for each packet inserted in the Low Priority Node filter queue based on whether or not a time equal to or greater than the “Traffic Control Timer” value has elapsed since the packet was enqueued. If the communication device X determines in step B270 that the time equal to or greater than the “Traffic Control Timer” value has not elapsed (NO in step B270), the communication device X returns to step B150 in FIG.

  On the other hand, if it is determined in step B270 that the time equal to or greater than the “Traffic Control Timer” value has elapsed (YES in step B270), the communication device X dequeues the packet from the Low Priority Node filter queue and performs relay processing in step B280. And return to Step B150 of FIG.

  In this way, while the traffic suppression message is valid (until the invalid time set in the traffic suppression message elapses), the IP packet corresponding to the “High Priority Host IP Address” notified by the traffic suppression message is normally On the other hand, the IP packet whose ToS value is equal to or less than “QoS Parameter” is relayed with a delay while the relay processing is performed as described above. Also, IP packets corresponding to “Low Priority Host IP Address” notified by traffic suppression messages are not relayed as long as the packet is inserted in the QoS filter queue, and no packet is inserted in the QoS filter queue. However, the relay processing is not performed unless the time exceeding the “Traffic Control Timer” value elapses.

  As a result, the communication device X that is the transmission source of the traffic suppression message can suppress the number of relay data from the other device that reaches the own device, so that it can secure a transmission opportunity of the data from which the own device is the transmission source. Can do.

  In the present embodiment, the value of the ToS field in the IP header is used for the QoS parameter. However, the value of the DiffServ field obtained by redefining the ToS field may be used. The packet enqueued in the Low Priority Node filter queue may be limited to the case where the destination MAC address of the packet is the MAC address of the source of the suppression message, or both the source IP and the destination IP are Low Priority Host. It may be specified in the IP Address. Further, even if a packet is specified with Low Priority Host IP Address as either the transmission source or the destination, the packet may be relayed if the QoS parameter of the ToS field value is higher than the QoS parameter of the suppression condition.

  The plurality of terminals Y may construct a wired autonomous network. Further, some of the plurality of communication devices X may not be connected to the terminal Y by wire. In this case, the communication device X may include only a wireless interface without including a wired interface. Further, the number of communication devices X and terminals Y may be increased or decreased.

The above embodiment will be outlined as follows.
(1) The wireless system according to the present embodiment is a wireless system including a plurality of wireless devices that perform wireless communication, and the second wireless device relays data transmitted from the first wireless device to the third wireless device. The second wireless device is configured to determine whether a predetermined suppression condition is met based on traffic information of the own device, and when the second wireless device meets the predetermined suppression condition, Relay control means for stopping the relay process by controlling to stop the selection of the plurality of wireless devices being selected as the relay device is provided.
(2) In addition, the relay control unit is selected by the plurality of wireless devices as the relay device when the number of the plurality of wireless devices having the own device as the relay device is a predetermined ratio or more. You may reduce the degree.
(3) In addition, when it is determined that the predetermined threshold condition is greater than or equal to the first threshold value and less than the second threshold value, a traffic suppression unit that suppresses the amount of data relayed by the own device; The relay control unit may stop the relay processing of the own device when it is determined that the threshold value is 2 or more.
(4) Further, the traffic suppression unit generates a suppression message for generating a suppression message for notifying a traffic control time for holding data whose source is the first wireless device or data whose destination is the third wireless device. Means and a transmission means for transmitting the suppression message to the plurality of the wireless devices, and the plurality of wireless devices that have received the notification message are data that the transmission source is the first wireless device, or When data whose destination is the third wireless device is received, relay data suppression means for holding the data for the traffic control time before relaying the data may be provided.
(5) The second wireless device may be an ad hoc network MPR.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention. Note that, in the above-described embodiment, the same reference numerals are given to configurations showing similar functions.

100: network module 101: control message generation unit 1011: suppression message generation unit 102: control message transmission unit 103: control unit 104: statistical information acquisition unit 105: filter / queue processing unit 106: routing information base 107: traffic control notification analysis Unit 108: Control message receiving unit 200: Filter packet queue 300: Routing table (RoutingTable)
3001: Routing table cache (RTcache)
400: EthernetMAC
401: EthernetPHY
402: WirelessMAC
403: WirelessNetworkPHY
X: Communication device Y: Terminal

Claims (2)

A wireless system including a plurality of wireless devices that perform wireless communication,
A second wireless device that relays data transmitted from the first wireless device to the third wireless device;
The second wireless device is
Determination means for determining whether a predetermined suppression condition is satisfied based on traffic information of the own device;
Relay control means for controlling a plurality of wireless devices that have selected their own device as a relay device to stop selection as the relay device and stopping relay processing when the predetermined suppression condition is met A wireless system characterized by comprising:   The relay control means reduces the selectivity selected by the plurality of wireless devices as the relay device when the number of the plurality of wireless devices having the own device as the relay device is a predetermined ratio or more. The wireless system according to claim 1, wherein:

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