JP4520350B2 - Wireless device - Google Patents

Description

  The present invention relates to a radio apparatus, and more particularly to a radio apparatus constituting an ad hoc network that is autonomously and instantaneously constructed by a plurality of radio apparatuses.

  An ad hoc network is a network that is autonomously and instantaneously constructed by a plurality of wireless devices communicating with each other. In an ad hoc network, when two wireless devices that communicate with each other do not exist in the communication area, a wireless device located between the two wireless devices functions as a router and relays a data packet. Can be formed.

  Such an ad hoc network is about to be applied to various fields such as a wireless communication network in a stricken area and streaming in ITS (Intelligent Transport Systems) inter-vehicle communication (Non-Patent Document 1).

  As a routing protocol that supports multi-hop communication, there are a table-driven protocol and an on-demand protocol. The table-driven protocol periodically exchanges control information related to a route and constructs a route table in advance, and includes GSR (Global State Routing), FSR (Fish-eye State Routing), OLSR (Optimized Link). State Routing) and DSDV (Destination Sequential Distance Vector) are known.

  In addition, the on-demand protocol is a method for constructing a route to a destination for the first time when a data transmission request occurs, and includes DSR (Dynamic Source Routing) and AODV (Ad Hoc On-Demand Distance Vector Routing). Are known.

  In a conventional ad hoc network, when data communication is performed from a transmission source to a transmission destination, a communication path is determined so that the number of hops from the transmission source to the transmission destination is as small as possible (Non-Patent Document 2).

In such an ad hoc network, each wireless device transmits and receives voice information to and from each other through a VoIP (Voice over Internet Protocol) session.
Masahiro Watanabe “Wireless Ad Hoc Network”, Automobile Engineering Society Spring Meeting Humantronics Forum, pp 18-23, Yokohama, May 2003. Guangyu Pei, at al, “Fisheye state routing: a routing scheme for ad hoc wireless networks”, ICC2000. Commun., Volume 1, pp70-74, LA, June 2000.

  However, in a VoIP session, QoS (Quality of Service) such as throughput and delay is required to be constant, and therefore, when the number of hops from the transmission source to the transmission destination is relatively small, there is a delay. Although the required QoS is relatively small and there is a margin in the required QoS, when the number of hops from the transmission source to the transmission destination is relatively large, the delay becomes relatively large and the required QoS can be satisfied. Can not. As a result, there is a problem that the required QoS cannot be satisfied stably.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a radio apparatus that can stably satisfy the required QoS.

  According to the present invention, a wireless device is a wireless device that is autonomously established and constitutes a wireless network in which wireless communication is performed between a transmission source and a transmission destination, and includes an allowable delay calculation unit, a scheduling, Means and a transmission means. The permissible delay calculation means in the radio apparatus so that radio communication is performed within the maximum permissible delay between the transmission source and the transmission destination for each of n packets (n is a positive integer) to be transmitted. Calculate the allowable delay. The scheduling means determines a transmission schedule of n packets based on the n allowable delays calculated by the allowable delay calculation means so that the n packets are transmitted within each corresponding allowable delay. The transmission means transmits n packets based on the transmission schedule determined by the scheduling means.

  Preferably, the allowable delay calculation means sets the allowable delay between the transmission source and the transmission destination determined according to the type of the packet to be transmitted as the maximum allowable delay, and the delay between the transmission source and the wireless device. Is the accumulated delay and the expected delay from the wireless device to the transmission destination is the remaining expected delay, subtracting the accumulated delay and the remaining expected delay from the maximum allowable delay to calculate each of the n allowable delays To do.

  Preferably, the wireless device further includes table holding means. The table holding means holds a routing table corresponding to n transmission destinations and including n remaining expected delays each consisting of a remaining expected delay from the wireless device to the transmission destination. Then, the allowable delay calculation means reads the maximum allowable delay and the accumulated delay from the packet subjected to the calculation of the allowable delay, and reads the remaining expected delay corresponding to the transmission destination of the packet subjected to the calculation of the allowable delay from the routing table. In addition, an allowable delay calculation process for calculating an allowable delay of a packet subject to the calculation of the allowable delay based on the read maximum allowable delay, accumulated delay, and remaining expected delay is executed for n packets, and n allowable delays are performed. Is calculated.

  Preferably, the wireless device further includes table holding means. The table holding unit holds a routing table corresponding to n transmission destinations and including n hop numbers each consisting of the number of hops from the wireless device to each transmission destination. Then, the allowable delay calculation means reads the number of hops to the destination of the packet that is the target of the calculation of the allowable delay from the routing table, calculates the remaining expected delay by multiplying the read hop number by a constant, The maximum allowable delay and cumulative delay are read from the packet subject to the delay calculation, and the allowable delay of the packet subject to the calculation of the allowable delay is calculated based on the read maximum allowable delay and cumulative delay and the calculated expected remaining delay. An allowable delay calculation process to be calculated is executed for n packets, and n allowable delays are calculated.

  Preferably, the wireless device further includes a delay calculation unit and an update unit. The delay calculation means calculates a self-delay that is a delay of each packet in the wireless device. The updating means reads the accumulated delay from the transmission target packet, adds the calculated self delay to the read accumulated delay, writes the addition result to the transmission target packet, and updates the accumulated delay n Execute on the packet. Then, when transmitting the packet based on the transmission schedule, the transmission unit updates the accumulated delay included in the packet, and transmits the packet including the updated accumulated delay.

  Preferably, the wireless device further includes a delay calculation unit, an average delay calculation unit, and a storage unit. The delay calculation means calculates a self-delay that is a delay of each packet in the wireless device. The average delay calculation means executes an average delay process for calculating an average delay in the wireless device for n packets. The storage means is, for each of the n packets, a delay in the wireless device of each already transmitted packet, and a self-delay sequentially calculated by the delay calculating means when the packet is transmitted. K (k is a positive integer) actual self-delays are stored. The average delay calculating means calculates an average delay based on the self delay calculated by the delay calculating means when each packet is transmitted and the k actual self delays stored in the storage means.

  Preferably, the wireless device further includes a delay calculation unit, an average delay calculation unit, and a storage unit. The delay calculation means calculates a self-delay that is a delay of each packet in the wireless device. The average delay calculation means executes an average delay process for calculating an average delay in the wireless device for n packets. The storage means is, for each of the n packets, a delay in the wireless device of each packet that has already been transmitted, and a self-delay sequentially calculated by the delay calculation means when the packet is transmitted, The previous average delay calculated by the average delay calculation means is stored. Then, the average delay calculation means calculates a new average delay based on the self delay calculated by the delay calculation means when each packet is transmitted and the previous average delay stored in the storage means.

  Preferably, the wireless device further includes a table holding unit, a delay table creating unit, and a table updating unit. The table holding means is provided corresponding to n transmission destinations, n transmission destinations, and n remaining expected delays each consisting of a remaining expected delay from the wireless device to the transmission destination, n A routing table is provided corresponding to each of the transmission destinations, and each includes n hop counts including the hop count from the wireless device to the transmission destination. The delay table creation means creates a delay table by adding the calculated n average delays to n remaining expected delays corresponding to n destinations of n packets. The table update means updates the routing table based on the delay table transmitted from another wireless device. The table updating unit updates the routing table when the first hop number included in the delay table is the same as the second hop number included in the routing table.

  Preferably, the table updating means changes the second remaining expected delay to the first remaining expected delay when the first remaining expected delay included in the delay table is smaller than the second remaining expected delay included in the routing table. Rewrite and update the routing table.

  The wireless device according to the present invention calculates n allowable delays in the wireless device of n packets so that wireless communication is performed within the maximum allowable delay between the transmission source and the transmission destination, and the calculated n Based on the permissible delays, the transmission schedule of n packets is determined so that n packets are transmitted within each corresponding permissible delay, and n packets are transmitted according to the determined transmission schedule.

  Therefore, according to the present invention, the required QoS can be stably satisfied.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram of a wireless network system using a wireless device according to an embodiment of the present invention. The wireless network system 10 includes wireless devices 1 to 6. The wireless devices 1 to 6 are arranged in a wireless communication space and autonomously configure a network. When transmitting data from the wireless device 1 to the wireless device 6, the wireless devices 2 to 5 relay the data from the wireless device 1 and deliver it to the wireless device 6.

  In this case, the wireless device 1 can perform wireless communication with the wireless device 6 through various routes. That is, the wireless device 1 can perform wireless communication with the wireless device 6 via the wireless devices 2 and 3 and can perform wireless communication with the wireless device 6 via the wireless devices 4 and 5. It is also possible to perform wireless communication with the wireless device 6 via the wireless devices 2, 4, 5, and perform wireless communication with the wireless device 6 via the wireless devices 2, 3, 5. It is also possible to perform wireless communication with the wireless device 6 via the wireless devices 2, 4, 5, 3.

  When wireless communication is performed via the wireless devices 2 and 3 or the wireless devices 4 and 5, the number of hops is the smallest “3”, and wireless communication is performed via the wireless devices 2, 4, 5 or the wireless devices 2, 3, and 5. , The number of hops is “4”, and when performing wireless communication via the wireless devices 2, 4, 5, 3, the number of hops is “5”, the largest.

  Accordingly, when a route for performing wireless communication via the wireless devices 2 and 3 or the wireless devices 4 and 5 is selected, the number of hops is the smallest “3”.

  In this case, for example, wireless communication is performed between the wireless device 1 and the wireless device 6 via the route of the wireless device 1 -the wireless device 2 -the wireless device 3 -the wireless device 6 with the smallest number of hops.

  However, when wireless communication is performed between the wireless device 1 and the wireless device 6 via the route of the wireless device 1 -the wireless device 2 -the wireless device 3 -the wireless device 6, the wireless device 1 is wirelessly connected via the wireless device 2. When a request for wireless communication to the device 4 is made from a wireless device (not shown) other than the wireless device 1, the number of packets transmitted by the wireless device 2 is larger than the number of packets transmitted by the wireless device 3. .

  In this case, if the wireless communication between the wireless device 1 and the wireless device 6 already performed is prioritized and the wireless device 2 transmits the packet received from the wireless device 1 with priority, the wireless device 1 There is a possibility that the throughput of wireless communication performed between the wireless device (not shown) other than the wireless device 4 and the wireless device 4 is lowered, and the required QoS cannot be satisfied.

  Therefore, in the following, a method for performing wireless communication by satisfying the required QoS in the wireless network system 10 will be described.

  The OLSR protocol is basically used as a protocol for establishing a communication path between a transmission source and a transmission destination. The OLSR protocol is a table-driven routing protocol, and is a protocol for exchanging route information by using a Hello message and a TC (Topology Control) message to create a routing table.

  FIG. 2 is a schematic block diagram showing the configuration of the wireless device 1 shown in FIG. The wireless device 1 includes an antenna 11, an input unit 12, an output unit 13, a user application 14, and a communication control unit 15.

  The antenna 11 receives data from other wireless devices via the wireless communication space, outputs the received data to the communication control unit 15, and transmits the data from the communication control unit 15 to other communication devices via the wireless communication space. Transmit to the wireless device.

  The input unit 12 accepts a message and data destination input by the operator of the wireless device 1 and outputs the accepted message and destination to the user application 14. The output unit 13 displays a message according to control from the user application 14.

  The user application 14 generates data based on the message and destination from the input unit 12 and outputs the data to the communication control unit 15.

  The communication control unit 15 includes a plurality of modules that perform communication control in accordance with an ARPA (Advanced Research Projects Agency) Internet hierarchical structure. That is, the communication control unit 15 includes a radio interface module 16, a MAC (Media Access Control) module 17, a buffer 18, an LLC (Logical Link Control) module 19, an IP (Internet Protocol) module 20, and a routing table 21. A TCP module 22, a UDP module 23, an SMTP (Simple Mail Transfer Protocol) module 24, and a routing daemon 25.

  The wireless interface module 16 belongs to the physical layer, modulates / demodulates a transmission signal or a reception signal according to a predetermined rule, and transmits / receives a signal via the antenna 11.

  The MAC module 17 belongs to the MAC layer, executes the MAC protocol, and executes various functions described below.

  That is, when the MAC module 17 transmits the route information in the wireless network system 10 to another wireless device, the MAC module 17 creates a packet PKT including various messages such as information related to the adjacent wireless device, and passes through the wireless interface module 16. Broadcast.

  The MAC module 17 performs retransmission control of data (packets). The MAC module 17 detects that the link has been disconnected when the number of retransmissions of data (packets) exceeds a predetermined value, and notifies the routing daemon 25 that the link has been disconnected.

  Further, the MAC module 17 adds the delay in the wireless device 1 to the accumulated delay included in the packet to be transmitted, and updates the accumulated delay. Then, the MAC module 17 transmits a packet including the updated accumulated delay via the wireless interface module 16.

  The buffer 18 belongs to the data link layer and temporarily stores packets.

  The LLC module 19 belongs to the data link layer, executes the LLC protocol, and executes transmission scheduling.

  The IP module 20 belongs to the Internet layer and generates an IP packet. The IP packet includes an IP header and an IP data portion for storing a packet of a higher protocol. When receiving data from the TCP module 22 or the UDP module 23, the IP module 20 stores the received data in the IP data portion and generates n (n is a positive integer) IP packets.

  In addition, the IP module 20 calculates an allowable delay in the wireless device 1 for each of the n IP packets by a method described later, and the n IP packets are calculated based on the calculated n allowable delays. A transmission schedule indicating a transmission order is determined.

  Then, the IP module 20 searches the routing table 21 according to the OLSR protocol, which is a table-driven routing protocol, and determines n routes for transmitting the generated n IP packets. Then, the IP module 20 transmits n IP packets to the LLC module 19 according to the transmission schedule, and transmits n IP packets to the transmission destination along the determined n paths.

  Further, the IP module 20 calculates an average delay in the wireless device 1 by a method described later, and creates a delay table reflecting the calculated average delay in the routing table 21. Then, the IP module 20 writes the created delay table in a routing packet and broadcasts it.

  The routing table 21 belongs to the Internet layer and stores path information in association with each transmission destination, as will be described later.

  The TCP module 22 belongs to the transport layer and generates a TCP packet. The TCP packet is composed of a TCP header and a TCP data part for storing data of an upper protocol. Then, the TCP module 22 transmits the generated TCP packet to the IP module 20.

  The UDP module 23 belongs to the transport layer, broadcasts an Update packet created by the routing daemon 25, receives an Update packet broadcast from another wireless device, and outputs it to the routing daemon 25.

  The UDP module 23 transmits a fixed-band data packet such as VoIP.

  The SMTP module 24 belongs to the process / application layer, and secures a full-duplex communication channel and exchanges messages based on data received from the user application 14.

  The routing daemon 25 belongs to the process / application layer, monitors the execution state of other communication control modules, and processes requests from other communication control modules. In addition, the routing daemon 25 periodically exchanges route information with other wireless devices that are relatively close according to the OLSR protocol, and calculates an optimum route based on the obtained route information and calculates the routing table 21. Create dynamically in the Internet layer.

  Note that each of the wireless devices 2 to 6 illustrated in FIG. 1 has the same configuration as that of the wireless device 1 illustrated in FIG. 2.

  FIG. 3 is a configuration diagram of a packet. The packet PKT includes a packet PKT1 shown in FIG. 3A or a packet PKT2 shown in FIG. The packet PKT1 includes a MAC header 31, a DL header 32, an IP header 33, a TCP header 34, a data unit 35, and an FCS (Frame Check Sequence) 36. The MAC header 31 is given by the MAC module 17 and includes a destination address and a transmission source address.

  The DL header 32 includes a maximum allowable delay unit 321 and a cumulative delay unit 322. The maximum allowable delay unit 321 stores a maximum allowable delay (MAX_Delay) that is determined according to the type of packet and that is an allowable delay between the transmission source and the transmission destination. The maximum allowable delay is set at the transmission source.

  The cumulative delay unit 322 stores a cumulative delay (delay) that is a sum of delays from the transmission source to the wireless device that is the relay, and is sequentially updated by the wireless device that is the relay. The cumulative delay is initially set to “0” in the source IP layer.

  The IP header 33 and the TCP header 34 will be described later. The data unit 35 stores data to be transmitted (DATA). The FCS 36 stores control information based on a CRC (Cyclic Redundancy Check character) method. In the CRC method, data is regarded as a high-order polynomial, and the remainder obtained by dividing the data by a predetermined generator polynomial is used as a bit string for error detection. On the receiving side, the data to which the bit string for error detection is added is divided by the same generator polynomial, and if there is no remainder, it is determined that the transmitted data is correct. Therefore, the FCS 35 stores the bit string for error detection (see (a) of FIG. 3).

  The packet PKT2 is the same as the packet PKT1 except that the TCP header 34 of the packet 1 is replaced with a UDP header 37 (see FIG. 3B). The UDP header 37 will be described later.

  FIG. 4 is a configuration diagram of the IP header 33. The IP header 33 includes a version, header length, service type, packet length, identification number, flag, fragment offset, lifetime, protocol, header checksum, source IP address, destination IP address, and options.

  FIG. 5 is a configuration diagram of a TCP header and a UDP header. FIG. 5A shows the configuration of the TCP header, and FIG. 5B shows the configuration of the UDP header. The TCP header includes a transmission source port number, a transmission destination port number, a sequence number, an acknowledgment (ACK) number, a data offset, a reservation, a flag, a window size, a header checksum, and an argent pointer.

  The transmission source port number is a number that identifies an application that has output a TCP packet when a plurality of applications are operating on the transmission source wireless device. The transmission destination port number is a number that identifies an application that delivers a TCP packet when a plurality of applications are operating on the transmission destination wireless device.

  TCP communication is an end-to-end connection-oriented communication protocol. A TCP module 22 of a wireless device that requests a connection connection of TCP communication (hereinafter referred to as “TCP communication connection request device”) has a connection in which SYN (Synchronize Flag) is set in Code Bit in the TCP header when the connection is established. The first packet indicating the connection request is transmitted to the TCP module 22 of the terminal that accepts the connection connection of TCP communication (hereinafter referred to as “TCP communication connection accepting device”). In response to this, the TCP module 22 of the TCP communication connection accepting apparatus connects the second packet indicating the connection request acceptance and connection completion of the connection in which SYN and ACK (acknowledgement) are set in the Code Bit in the TCP header to the TCP communication connection. Transmit to the TCP module 22 of the requesting device. In response to this, the TCP module 22 of the TCP communication connection requesting device sends a third packet indicating the completion of connection of the connection in which the Code Bit in the TCP header is set to ACK (acknowledgment response) to the TCP of the TCP communication connection receiving device. Transmit to module 22.

  The connection disconnection request can be made from either the TCP communication requesting device or the TCP communication receiving device. A TCP module 22 of a wireless device that requests disconnection of TCP communication (hereinafter referred to as “TCP communication disconnection request device”) has a connection in which Code Bit in the TCP header is set to FIN (Finish Flag) when the connection is disconnected. The first packet indicating the disconnection request is transmitted to the wireless device that accepts the disconnection of the TCP communication (hereinafter referred to as “TCP communication disconnection accepting device”). In response to this, the TCP module 22 of the TCP communication disconnection accepting apparatus receives the second packet indicating acceptance of the disconnection request for the connection in which the Code Bit in the TCP header is set to ACK (acknowledgment response), and the Code Bit in the TCP header. A third packet indicating completion of disconnection of the connection set in FIN is transmitted to the TCP module 22 of the TCP communication disconnection requesting device. Further, in response to this, the TCP module 22 of the TCP communication disconnection requesting device sends a fourth packet indicating the completion of disconnection of the connection in which the Code Bit in the TCP header is set to ACK (acknowledgment response) to the TCP communication disconnection receiving device TCP. Transmit to module 22.

  The UDP header includes a transmission source port number, a transmission destination port number, a UDP data length, and a UDP checksum.

  The transmission source port number is a number that identifies an application that has output a UDP packet when a plurality of applications are operating in the transmission source wireless device. The transmission destination port number is a number that identifies an application that delivers a UDP packet when a plurality of applications are operating on the transmission destination wireless device.

  FIG. 6 is a configuration diagram of the routing table 21 shown in FIG. The routing table 21 includes a routing table 21A shown in FIG. 6A or a routing table 21B shown in FIG.

  The routing table 21A includes a transmission destination, the next wireless device, the number of hops, and the remaining expected delay. The transmission destination, the next wireless device, the number of hops, and the remaining expected delay are associated with each other. “Destination” represents the IP address of the destination wireless device. “Next wireless device” represents the IP address of the wireless device to be transmitted next when transmitting the packet PKT to the transmission destination. “Hop number” represents the number of hops to the destination. “Remaining expected delay” is the sum of delays of the wireless devices between each wireless device and the transmission destination. For example, in FIG. 1, when wireless communication is performed between the wireless device 1 and the wireless device 6 through the route of the wireless device 1 -the wireless device 2 -the wireless device 3 -the wireless device 6, the routing table 21 A of the wireless device 2 In the remaining expected delay, the delay in the wireless device 3 is stored. When wireless communication is performed between the wireless device 1 and the wireless device 6 through the route of the wireless device 1 -the wireless device 2 -the wireless device 4 -the wireless device 5 -the wireless device 6, the routing table 21 A of the wireless device 2 The remaining expected delay stores the sum of the delay in the wireless device 4 and the delay in the wireless device 5 (see FIG. 6A).

  The routing table 21B is obtained by deleting the remaining expected delay from the routing table 21A, and is otherwise the same as the routing table 21A (see FIG. 6B).

  The creation of the routing tables 21A and 21B according to the OLSR protocol will be described in detail. The wireless devices 1 to 6 transmit and receive a Hello message and a TC message when creating the routing tables 21A and 21B.

  The Hello message is periodically transmitted for the purpose of distributing information held by the wireless devices 1 to 6. By receiving this Hello message, each of the wireless devices 1 to 6 can collect information on surrounding wireless devices and recognizes what wireless devices exist around the wireless device.

  In the OLSR protocol, each of the wireless devices 1 to 6 manages local link information. The Hello message is a message for constructing and transmitting the local link information. The local link information includes “link set”, “adjacent radio device set”, “two-hop adjacent radio device set and link set to those radio devices”, “MPR (Multipoint Relay) set”, and “MPR selector set”. including.

  A link set is a link to a set of wireless devices (adjacent wireless devices) through which radio waves directly reach, and each link is expressed by an effective time of a set of addresses between two wireless devices. The valid time is also used to indicate whether the link is unidirectional or bidirectional.

  The neighboring wireless device set is configured by the address of each neighboring wireless device, the retransmitting degree (Willingness) of the wireless device, and the like. The 2-hop adjacent wireless device set represents a set of wireless devices adjacent to the adjacent wireless device.

  The MPR set is a set of wireless devices selected as MPRs. Note that MPR means that when each packet PKT is transmitted to all the wireless devices 1 to 6 of the wireless network system 10, each wireless device 1 to 6 transmits and receives all the packets PKT by transmitting and receiving one packet PKT only once. The relay wireless device is selected so that it can be transmitted to the wireless devices 1-6.

  The MPR selector set represents a set of wireless devices that have selected themselves as MPRs.

  The process of establishing local link information is generally as follows. In the initial stage of the Hello message, each of the wireless devices 1 to 6 transmits a Hello message containing its own address to an adjacent wireless device in order to inform the existence of the device. All of the wireless devices 1 to 6 perform this operation, and each of the wireless devices 1 to 6 grasps what address a wireless device has around itself. In this way, a link set and an adjacent wireless device set are constructed.

  The constructed local link information is continuously sent again by a Hello message again. By repeating this, it is gradually clarified whether each link is bidirectional or what kind of wireless device exists ahead of the adjacent wireless device. Each of the wireless devices 1 to 6 stores local link information that is gradually constructed in this way.

  Further, information regarding MPR is also periodically transmitted by a Hello message and notified to each wireless device 1-6. Each of the wireless devices 1 to 6 selects several wireless devices from among adjacent wireless devices as an MPR set as wireless devices that request retransmission of the packet PKT transmitted by the wireless devices 1 to 6. Then, since the information regarding this MPR set is transmitted to the adjacent radio apparatus by the Hello message, the radio apparatus that has received this Hello message sets the set of radio apparatuses that it has selected as the MPR as the “MPR selector set”. to manage. By doing in this way, each radio | wireless apparatus 1-6 can recognize immediately which packet PKT received should be retransmitted.

  When a local link set is established in each of the wireless devices 1 to 6 by transmitting and receiving the Hello message, a TC message for notifying the topology of the entire wireless network system 10 is transmitted to the wireless devices 1 to 6. This TC message is periodically transmitted by all wireless devices selected as MPRs. Since the TC message includes a link between each wireless device and the MPR selector set, all the wireless devices 1 to 6 of the wireless network system 10 know all the MPR sets and all the MPR selector sets. Based on all the MPR sets and all the MPR selector sets, the topology of the entire wireless network system 10 can be known. Each of the wireless devices 1 to 6 calculates the shortest path using the topology of the entire wireless network system 10 and creates a route table based on the calculated shortest path.

  In addition, each radio | wireless apparatus 1-6 exchanges a TC message frequently separately from a Hello message. MPR is also used for exchanging TC messages.

  The UDP module 23 of each wireless device 1-6 transmits and receives the above-mentioned Hello message and TC message, and the routing daemon 25 determines the topology of the entire wireless network system 10 based on the Hello message and TC message received by the UDP module 23. The shortest path is calculated based on the overall topology of the wireless network system 10, and the routing tables 21A and 21B shown in FIG. 6 are dynamically created based on the shortest path.

  FIG. 7 is a functional block diagram of the IP module 20 shown in FIG. The IP module 20 includes an IP input queue unit 201, an IP option processing unit 202, a destination identifying unit 203, an IP output unit 204, a timer 205, and a memory 206.

  The IP input queue unit 201 receives a packet from a network interface such as the MAC module 17, suppresses the loss of the received packet, and outputs the packet to the IP option processing unit 202.

  The IP option processing unit 202 performs option processing on the packet from the IP input queue unit 201 and outputs the packet to the destination identification unit 203 or the IP output unit 204.

  The destination identifying unit 203 detects a destination address included in the IP header 33 of the packet PKT from the IP option processing unit 202, and determines whether the packet PKT is a packet addressed to the own terminal based on the detected destination address. judge. Then, when the packet PKT is a packet addressed to its own terminal, the destination identifying unit 203 outputs the packet PKT to the TCP module 22 or the UDP module 23. Further, the destination identifying unit 203 outputs the packet PKT to the IP output unit 204 when the packet PKT is not a packet addressed to the own terminal.

  The IP output unit 204 receives the packet PKT from any one of the destination identifying unit 203, the TCP module 23, and the UDP module 23. When receiving the packet PKT, the IP output unit 204 detects the time arriving_time when the packet PKT is received with reference to the timer 205 and also detects the identification number included in the IP header 33 of the packet PKT. Then, the IP output unit 204 records the detected time arriving_time and the identification number in the memory 206 in association with each other.

  Further, the IP output unit 204 reads the maximum allowable delay (MAX_Delay) from the maximum allowable delay unit 321 included in the DL header 32 of the packet PKT, and corresponds to the transmission destination of the packet PKT from the routing table 21 (= routing table 21A). Read the remaining expected delay. Then, the IP output unit 204 calculates the allowable delay in each wireless device using the following equation based on the read maximum allowable delay (MAX_Delay), accumulated delay (before update), and remaining expected delay.

ＬＬＣモジュール１９は、ｎ個のパケットについて式（１）に従って許容遅延を演算し、その演算したｎ個の許容遅延に基づいて、ｎ個のパケットの送信順序を示す送信スケジュールを作成する。なお、式（１）に従って許容遅延を演算することは、送信元と送信先との間で最大許容遅延内に無線通信が行なわれるように各無線装置１〜６における許容遅延を演算することに相当する。

The LLC module 19 calculates an allowable delay for n packets according to the equation (1), and creates a transmission schedule indicating the transmission order of the n packets based on the calculated n allowable delays. Note that computing the permissible delay according to equation (1) means computing the permissible delay in each of the radio apparatuses 1 to 6 so that radio communication is performed within the maximum permissible delay between the transmission source and the transmission destination. Equivalent to.

  Further, the MAC module 17 detects the time system_time when the packet PKT is transmitted with reference to the timer 205 and subtracts the time arriving_time from the time system_time to delay (delay_u = system_time-arrival_time) in each of the wireless devices 1 to 6. ) Is calculated. Then, the MAC module 17 reads the accumulated delay (delay) from the accumulated delay unit 322 included in the DL header 32 of the packet PKT, adds the calculated delay (delay_u) to the read accumulated delay (delay), and accumulates the accumulated delay. (Delay) is updated, and a packet in which the accumulated delay (delay) is updated is transmitted.

  When the routing table 21 includes the routing table 21B shown in FIG. 6B, the IP output unit 204 reads the number of hops from the routing table 21B, and multiplies the read hop number by a constant to calculate the remaining expected delay. To do. When the number of hops is TTL, the IP output unit 204 calculates TTL × C (C is a constant), and sets the calculation result as the remaining expected delay (= TTL × C). Then, the IP output unit 204 calculates the allowable delay by substituting the calculated remaining expected delay (= TTL × C) into Equation (1). The constant C is set to 1.0 [msec], for example. Therefore, when the number of hops to the transmission destination is “3”, the remaining expected delay is calculated as 3 × 1.0 = 3.0 msec.

  As described above, when the routing table 21 includes the routing table 21B, the IP output unit 204 calculates an allowable delay according to the following equation.

図８は、許容遅延と優先度との関係を示す図である。図８において、縦軸は、優先度を表し、横軸は、許容遅延を表す。優先度と許容遅延との関係は、直線ｋ１によって表される。即ち、優先度は、許容遅延が相対的に大きくなれば、相対的に低く設定され、許容遅延が相対的に小さくなれば、相対的に高く設定される。

FIG. 8 is a diagram illustrating the relationship between the allowable delay and the priority. In FIG. 8, the vertical axis represents priority, and the horizontal axis represents allowable delay. The relationship between the priority and the allowable delay is represented by a straight line k1. That is, the priority is set relatively low when the allowable delay is relatively large, and is relatively high when the allowable delay is relatively small.

  Therefore, the LLC module 19 arranges the n allowable delays in ascending order and determines the transmission order in ascending order of the allowable delay. For example, when the three allowable delays corresponding to the three packets PKT1, PKT2, and PKT3 are 8 (msec), 5 (msec), and 10 (msec), respectively, the IP output unit 204 receives the packet PKT2 The transmission schedule is determined so that transmission is performed in the order of packet PKT1 → packet PKT3.

  Then, the LLC module 19 transmits n packets via the MAC module 17 in the determined order.

  Further, the IP output unit 204 sequentially calculates the delay (delay_u) in each of the wireless devices 1 to 6 by the method described above, and sequentially stores the calculated delay (delay_u) in the memory 206. That is, the IP output unit 204 sequentially stores, in the memory 206, data x (i) indicating delay (delay_u) (i is a positive integer indicating the generation order of the data x). Then, when the IP output unit 204 newly calculates the data x (N) (= the newly calculated delay in each of the wireless devices 1 to 6), N−1 (N is 2) that has already been calculated and stored in the memory 206. The above integer) pieces of data x (1) to x (N-1) are read from the memory 206, and the N-1 pieces of read data x (1) to x (N-1) are newly calculated. By substituting x (N) into the following equation, an average delay y (j) in each of the wireless devices 1 to 6 is calculated.

なお、Ｎは、サンプル数を表す。

N represents the number of samples.

  The IP output unit 204 calculates an average delay y (j) for each of the n packets.

  When the IP output unit 204 calculates the average delay y (j) for n packets, a delay table is obtained by adding the average delay y (j) to the n remaining expected delays corresponding to the destinations of the n packets. Created with reference to the routing table 21. Then, the IP output unit 204 broadcasts the created delay table via the network interface (wireless interface module 16).

  The timer 205 automatically updates the time as time elapses, and outputs the time system_time to the IP output unit 204 in response to a request from the IP output unit 204.

  FIG. 9 is a correspondence diagram between time and identification number. The identification number is associated with the time system_time. The time system_time is composed of YYYY / MM / HH / MM / SS and represents each time. The identification number is a 16-bit numerical value NNN... N and represents each packet PKT. The memory 206 stores the correspondence table shown in FIG.

  FIG. 10 is a diagram illustrating a relationship between an application and the maximum allowable delay. DV Audio / Video has a maximum allowable delay of 200 msec, SDTV (Satellite Digital TV) has a maximum allowable delay of 200 msec, and Video conference has a maximum allowable delay of 100 msec.

  In addition, Internet streaming Audio / Video has a maximum allowable delay of 200 msec, MP3 Audio has a maximum allowable delay of 200 msec, VoIP has a maximum allowable delay in the range of 150 to 300 msec, and Interactive Gaming has a maximum allowable delay. The delay is 10 msec.

  Furthermore, Video phone has a maximum allowable delay of 400 msec, and Remote user interface has a maximum allowable delay of 100 msec.

  Thus, the maximum allowable delay is set corresponding to each application.

  FIG. 11 is a flowchart for explaining an operation from generation of a packet to scheduling of a transmission order. FIG. 12 is a first example of the routing table 21A shown in FIG. The scheduling operation will be described assuming that a packet is generated in the wireless device 1.

  When a series of operations is started, upon receiving data from the UDP module 23, the IP output unit 204 of the IP module 20 stores the received data in the IP data unit, generates an IP header 33, and generates an IP packet PKT. Is created (step S1). In this case, the IP output unit 204 generates five IP packets PKT <b> 1 to PKT <b> 5 whose transmission destinations are wireless devices 2 to 6, respectively.

  Then, the IP output unit 204 of the IP module 20 refers to the timer 205 and writes the times system_time1 to system_time5 when the IP packets PKT1 to PKT5 are created, respectively, as the generation times arriving_time1 to arriving_time5 in the memory 206 (step S2).

  Thereafter, the IP output unit 204 initializes the accumulated delay (delay) stored in the accumulated delay unit 322 of the DL header 32 of the IP packets PKT1 to PKT5 (step S3). More specifically, the IP output unit 204 initializes the cumulative delay delay by writing the cumulative delay delay of “0” into the cumulative delay portion 322 of each DL header 32 of the IP packets PKT1 to PKT5.

  Subsequently, the IP output unit 204 initializes the maximum allowable delay (step S4). More specifically, when the IP packets PKT1 to PKT5 are composed of voice data, the IP output unit 204 selects an appropriate value from the range of 150 to 300 msec corresponding to VoIP, and uses the selected value as the maximum allowable delay. Write to the maximum allowable delay unit 321 of the DL header 32 to initialize the maximum allowable delay. Further, when the IP packets PKT1 to PKT5 are composed of data other than voice data, the IP output unit 204 extracts the maximum allowable delay based on the correspondence table between the application and the maximum allowable delay shown in FIG. The allowable delay is written in the maximum allowable delay unit 321 of the DL header 32 to initialize the maximum allowable delay.

  Thereafter, the IP output unit 204 sets the destinations of the IP packets PKT1 to PKT5 (step S5), and sets the remaining expected delay corresponding to the set destinations in the routing table 211 (a type of routing table 21A, see FIG. 12). ) For extraction (step S6). In this case, when the transmission destination is the wireless device 2 or 4, the IP output unit 204 extracts “0.0” msec as the remaining expected delay, and when the transmission destination is the wireless device 3, the IP output unit 204 When “2.4” msec is extracted as the remaining expected delay and the transmission destination is the wireless device 5, the IP output unit 204 extracts “3.2” msec as the remaining expected delay, and the transmission destination is the wireless device. If it is 6, the IP output unit 204 extracts “5.6” msec as the remaining expected delay.

  Then, the IP output unit 204 substitutes the accumulated delay (delay = 0) initialized in step S3, the maximum allowable delay initialized in step S4, and the remaining expected delay extracted in step S6 into equation (1). Then, permissible delays delay_allow1 to delay_allow5 are calculated for each packet PKT1 to PKT5.

  More specifically, when the same maximum permissible delay (= 200 ms) is stored in the maximum permissible delay unit 321 of the packets PKT1 to PKT5, the IP output unit 204 determines that the permissible delay delay_allow1 = 200−0.0−0.0. = 200 msec, allowable delay delay_allow2 = 200−0.0−2.4 = 197.6 msec, allowable delay delay_allow3 = 200−0.0−0.0 = 200 msec, allowable delay delay_allow4 = 200−0.0−3.2 = 196.8 msec is calculated, and allowable delay delay_allow5 = 200−0.0−5.6 = 194.4 msec is calculated.

  When the maximum permissible delays of 100 msec, 200 msec, 150 msec, 300 msec, and 400 msec are stored in the maximum permissible delay unit 321 of the packets PKT1 to PKT5, the IP output unit 204 allows the permissible delay delay_allow1 = 100−0.0−0. 0.0 = 100 msec, allowable delay delay_allow2 = 200−0.0−2.4 = 197.6 msec, allowable delay delay_allow3 = 150−0.0−0.0 = 150 msec, allowable delay delay_allow4 = 300−0.0−3.2 = 296.8 msec is calculated, and allowable delay delay_allow5 = 400−0.0−5.6 = 394.4 msec is calculated.

  Then, the IP output unit 204 transmits the packet to the LLC module 19.

  Subsequently, the LLC module 19 extracts priorities corresponding to the calculated five allowable delays delay_allow1 to delay_allow5 with reference to the straight line k1 (see FIG. 8), and determines the priorities (step S7).

  More specifically, the LLC module 19 sets a relatively low priority for a packet having a relatively large allowable delay, and sets a priority for a packet having a relatively small allowable delay. The priority of the five packets PKT1 to PKT5 is determined with a relatively high setting. Therefore, for example, the LLC module 19 sets the priority of the packet PKT1,3 having an allowable delay of 200ms to the lowest, sets the priority of the packet PKT2 having an allowable delay of 197.6ms to the next lowest, and 196. The priority of the packet PKT4 having the allowable delay of 8 ms is set to the second highest, the priority of the packet PKT5 having the allowable delay of 194.4 ms is set to the highest, and the priority of the five packets PKT1 to PKT5 is determined. To do.

  Then, the LLC module 19 determines the transmission order based on the determined priority, has the determined transmission order, and transmits the packets PKT1 to PKT5 within the allowable delays delay_allow1 to delay_allow5, respectively. A schedule is created (step S8). More specifically, the LLC module 19 sets the transmission order of packets having a relatively high priority relatively early, and sets the transmission order of packets having a relatively low priority relatively late. The transmission schedule is created so that the packets PKT1 to PKT5 are transmitted within the allowable delays delay_allow1 to delay_allow5, respectively.

  Thus, the scheduling operation at the time of packet generation ends.

  FIG. 13 is a flowchart for explaining the scheduling operation when a packet is received. FIG. 14 is a second example of the routing table 21A shown in FIG.

  When a series of operations is started, the IP output unit 204 of the IP module 20 receives five packets PKT1 to PKT5 transmitted from other wireless devices from the destination identifying unit 203 (step S11). Then, the IP output unit 204 of the IP module 20 extracts the times system_time1 to system_time5 when the packets PKT1 to PKT5 are received, respectively, as arrival times arriving_time1 to arriving_time5, and writes the extracted arrival times arriving_time1 to arriving_time5 into the memory 206. (Step S12).

  Thereafter, the IP output unit 206 reads the accumulated delay (delay) from the accumulated delay unit 322 of the DL header 32 for each of the packets PKT1 to PKT5 (step S13), and reads the source IP address (step S14). Then, the IP output unit 204 calculates the average of the read accumulated delay (delay), and sets the average value of the calculated accumulated delay (delay) as the transmission destination indicated by the read IP address. The remaining expected delay in case.

  Subsequently, the IP output unit 204 reads the maximum allowable delay from the maximum allowable delay unit 321 of each DL header 32 of the packets PKT1 to PKT5 (step S15), and further reads the transmission destination from each of the packets PKT1 to PKT5 ( Step S16).

  Then, the IP output unit 204 extracts the remaining expected delay corresponding to each read destination with reference to the routing table 212 (a kind of routing table 21A, see FIG. 14) (step S17). In this case, the IP output unit 204 extracts the remaining expected delay of “0.0” msec when the transmission destination is the wireless devices 2 and 4, and “2” when the transmission destination is the wireless devices 3 and 5. The remaining expected delay consisting of .4 "msec is extracted. When the transmission destination is the wireless device 6, the remaining expected delay consisting of" 5.6 "msec is extracted.

  Thereafter, the IP output unit 204 substitutes the cumulative delay (delay) read in step S13, the maximum allowable delay read in step S15, and the remaining expected delay extracted in step S17 into the equation (1), to packet PKT1. Allowable delay delay_allow1 to delay_allow5 are calculated for each PKT5.

  Then, the IP output unit 204 transmits the packet to the LLC module 19. Subsequently, the LLC module 19 extracts priorities corresponding to the calculated five allowable delays with reference to the straight line k1 (see FIG. 8), and determines the priorities (step S18).

  More specifically, a packet having a relatively large permissible delay is set with a relatively low priority, and a packet having a relatively small permissible delay is set with a relatively high priority and is set to 5 packets. Priorities of the packets PKT1 to PKT5 are determined.

  Then, the LLC module 19 determines the transmission order based on the determined priority, has the determined transmission order, and transmits the packets PKT1 to PKT5 within the allowable delays delay_allow1 to delay_allow5, respectively. A schedule is created (step S19). More specifically, the LLC module 19 sets the transmission order relatively early for a packet having a relatively high priority, and relatively slow the transmission order for a packet having a relatively low priority. The transmission order of the packets PKT1 to PKT5 is determined by setting, and the transmission schedule for transmitting the packets PKT1 to PKT5 within the calculated allowable delays delay_allow1 to delay_allow5 is created.

  Then, according to the transmission schedule determined by the LLC module 19 (see step S8 in FIG. 11 or step S19 in FIG. 13), packets PKT1 to PKT5 are transmitted to the MAC module 17 within each calculated allowable delay.

  Thereby, the scheduling operation at the time of packet reception ends.

  FIG. 15 is a flowchart for explaining the operation from the packet transmission instruction to the packet transmission. FIG. 16 shows a past delay recording format in one wireless apparatus.

  When a series of operations is started, packet transmission is permitted (step S21). Then, the MAC module 17 refers to the timer 205 and extracts the time system_time when the packet transmission is permitted as the current time (step S22).

  Thereafter, the MAC module 17 reads the accumulated delays delay1 to delay5 from the accumulated delay units 322 of the packets PKT1 to PKT5 to be transmitted (step S23), and arrives at arrival times arriving_time1 to arriving_time5 (steps in FIG. 11). S2 or step S12 of FIG. 13) is read (step S24).

  Then, the MAC module 17 subtracts the arrival time arriving_time (any of the arrival times arriving_time1 to arriving_time5) from the current time system_time for the five arrival times arriving_time1 to arriving_time5, and subtracts the five packets PKT1 to PKT5. Delays delay_u1 to delay_u5 in each of the wireless devices 1 to 6 are calculated.

  Then, the MAC module 17 adds the calculated delays delay_u1 to delay_u5 to the cumulative delays delay1 to delay5, respectively, and updates the cumulative delays delay1 to delay5 (step S25).

  Then, the MAC module 17 writes the updated accumulated delays delay1 to delay5 in the accumulated delay unit 322 of the DL header 32 of the packets PKT1 to PKT5 (step S26), and transmits the packets PKT1 to PKT5 (step S27).

The system memory 206 stores the delays x (1) to x (N−1) in the wireless device 1 calculated in the past transmission of the packets PKT1 to PKT5 in the format shown in FIG. That is, the memory 206 associates N−1 delays x ₂ (1), x ₂ (2),..., X ₂ (N−1) in association with the wireless device 2 that is the transmission destination of the packet PKT1. Storing N−1 delays x ₃ (1), x ₃ (2),..., X ₃ (N−1) in association with the wireless device 3 that is the transmission destination of the packet PKT 2, N-1 delays x ₄ (1), x ₄ (2),..., X ₄ (N−1) are stored in association with the wireless device 4 that is the transmission destination of the packet PKT 3, and the packet PKT 4 N-1 delays x ₅ (1), x ₅ (2),..., X ₅ (N−1) are stored in association with the wireless device 5 that is the transmission destination, and the transmission destination of the packet PKT ₅ N−1 delays x ₆ (1), x ₆ (2),..., X ₆ (N−1) are stored in association with a certain wireless device 6.

Therefore, after step S27, the IP output unit 204 of the IP module 20 calculates the N−1 delays x ₂ (1), x ₂ (2), N ₂ in the wireless device 1 calculated in the past transmission of the packets PKT1 to PKT5. ..., x ₂ (N-1); x ₃ (1), x ₃ (2), ..., x ₃ (N-1); x ₄ (1), x ₄ (2), ... , X ₄ (N-1); x ₅ (1), x ₅ (2), ..., x ₅ (N-1); x ₆ (1), x ₆ (2), ..., x ₆ (N−1) is read from the memory 206.

Then, the IP output unit 204 reads the delay x ₂ (1), x ₂ (2),..., X ₂ (N−1) and the delay delay_u1 (= x ₂ (N) calculated in step S25. )) Is substituted into the expression (3) to calculate the average delay y ₂ (j) in the wireless device 1 of the packet PKT1 having the wireless device 2 as the transmission destination.

Similarly, the IP output unit 204 determines the average delays y ₃ (j), y ₄ (j), y ₅ (j), y in the wireless device 1 of the packets PKT2 to PKT5 whose destinations are the wireless devices 3 to 6. ₆ (j) is calculated (step S28). Then, the IP output unit 204 sets the calculated average delay y ₂ (j) to y ₆ (j) as a new average delay, and updates the average delay (step S29).

  Thereby, a series of operation | movement is complete | finished.

  As described above, when packets PKT1 to PKT5 are transmitted, the cumulative delay unit 322 of each packet PKT1 to PKT5 is updated and transmitted (see step S25 to step S27). Then, after transmitting the packets PKT1 to PKT5, the average delay in the wireless device that transmitted the packets PKT1 to PKT5 is calculated for the packets PKT1 to PKT5, and the average delay is updated (see steps S28 and S29).

  FIG. 17 is a flowchart for explaining the operation of the MAC module 17 shown in FIG. When a series of operations is started, the MAC module 17 receives a packet to be transmitted from the LLC module 19 which is an upper layer (step S31).

  Thereafter, the MAC module 17 performs a back-off process (step S32), and confirms the channel state during an IFS (Interframe Space) time (step S33). If the channel is “busy”, the series of operations proceeds to step S40.

  On the other hand, if the channel is “idle”, the MAC module 17 writes the accumulated delay delay in the accumulated delay section 322 of the packet PKT and updates the delay with the accumulated delay (step S34).

  Thereafter, the MAC module 17 transmits the packet PKT via the wireless interface module 16 and the antenna 11 (step S35), and determines whether or not the transmission of the packet PKT is successful (step S36).

  When it is determined in step S36 that the packet PKT has been successfully transmitted, the above-described steps S31 to S36 are repeatedly executed.

  On the other hand, when it is determined in step S36 that transmission of the packet PKT has failed, the MAC module 17 performs retransmission control of the packet PKT (step S37), and then determines whether the number of retransmissions retry_limit has exceeded. (Step S38).

  Then, when the number of retransmissions retry_limit has not exceeded, the MAC module 17 increases CW (Contention Window) exponentially (step S39).

  Then, in step S33, when the channel is “busy” or after step S39, the MAC module 17 sets a back-off timer between 0 and CW (step S40), and the set back-off timer is set. Wait for a while.

  In this case, the MAC module 17 counts the number of retransmissions retry_limit and executes exponential backoff that exponentially increases the value of CW as the counted number of retransmissions retry_limit increases (see step S39).

  Then, after step S40, the series of operations proceeds to step S32, and the above-described steps S32 to S40 are repeatedly executed until it is determined in step S38 that the number of retransmissions retry_limit has been exceeded.

  If it is determined in step S38 that the number of retransmissions retry_limit has been exceeded, the MAC module 17 discards the packet PKT (step S41). As a result, the operation of the MAC module 17 that transmits the packet ends.

  As described above, the MAC module 17 updates the accumulated delay unit 322 included in the DL header 32 of each packet PKT1 to PKT5 (see step S34), and transmits the updated packets PKT1 to PKT5 (see step S34). Step S35).

  Therefore, in the wireless ad hoc network, the wireless device that relays the packet PKT between the transmission source and the transmission destination sequentially updates the cumulative delay unit 322 of the packet PKT received from the transmission source side, and the cumulative delay unit 322 is updated. The packet PKT is transmitted to the next wireless device on the transmission destination side.

  As a result, the wireless device that relays the packet PKT between the transmission source and the transmission destination reads the accumulated delay delay from the accumulated delay unit 322 of the packet PKT received from the transmission-side wireless device. Since the accumulated delay delay is a total sum of delays in at least one repeater (at least one wireless device) existing on the transmission source side, the allowable delay in itself can be accurately calculated by the equation (1).

  Each wireless device 1-6 calculates the average delay in itself when relaying the packet PKT, and updates the past average delay with the calculated average delay (see steps S28 and S29 in FIG. 15). Accordingly, each of the wireless devices 1 to 6 holds the latest average delay in itself when relaying the packet PKT.

  Therefore, each of the wireless devices 1 to 6 creates and broadcasts a delay table in which the remaining expected delay of the routing table 21 is updated with the updated average delay.

  FIG. 18 is a flowchart for explaining operations of creating and transmitting a delay table in each wireless device. FIG. 19 is a diagram showing the concept of creating a delay table from the routing table 21. In the following, a case where the wireless device 2 creates a delay table will be described as an example. The wireless device 2 will be described as relaying one packet. Further, a description will be given assuming that the delay in the wireless device 2 is “3.0” msec.

  When a series of operations is started, generation of a routing packet PKT_RT is instructed (step S41). Here, the routing packet PKT_RT refers to a packet that can include a delay table in the data portion. After step S41, the IP output unit 204 of the IP module 20 determines whether or not to transmit average delay information (step S42).

  When it is determined in step S42 that average delay information is not transmitted, a routing packet that does not include a delay table is generated, and the series of operations proceeds to step S45.

  On the other hand, when it is determined in step S42 that average delay information is to be transmitted, the routing daemon 25 adds the average delay of the wireless device 2 to the remaining expected delay of the routing table 21 (step S43).

  In this case, the wireless device 2 holds a routing table 213 (a kind of routing table 21A) shown in FIG. Since the wireless device 2 is adjacent to the wireless devices 1, 3, and 4, in the routing table 213, the remaining expected delay corresponding to the wireless devices 1, 3 and 4 that are the transmission destinations is “0.0” msec It is. Also, since the wireless device 2 transmits a packet to the wireless device 5 via the wireless device 4 and transmits a packet to the wireless device 6 via the wireless device 3, the wireless device 2 corresponds to the wireless devices 5 and 6 that are transmission destinations. The remaining expected delay is set to, for example, “2.4” msec and “2.5” msec, respectively.

  The routing daemon 25 then sends delays “0.0” msec, “0.0” msec, “0.0” msec, “2. A delay table 230 shown in FIG. 19 is created by adding a delay of “3.0” msec in the wireless apparatus 2 to 4 ”msec and“ 2.5 ”msec.

  Since the delay table 230 is broadcast from the wireless device 2 and transmitted from the wireless device 2 to the wireless device within one hop, in the delay table 230, the wireless devices 1, 3, 4, 5, and 6 are set as transmission destinations. The “next wireless device” on the route is all “wireless device 2”. In addition, since it is assumed that the wireless device that has received the delay table 230 transmits the wireless device 2 to the wireless device 2, the delay table 230 includes a route having the wireless device 2 as a transmission destination, and corresponds to the wireless device 2 that is the transmission destination. The remaining expected delay is “0.0” msec. Further, since the delay table 230 includes a route passing through the wireless device 2, the “hop number” of the route having the wireless devices 1, 3, 4, 5, 6 as the transmission destination is the “hop number” in the routing table 213. It is “1” more than that.

  When the routing daemon 25 creates the delay table 230 by the method described above, it creates the routing packet PKT_RT by writing the created delay table 230 into the data part (step S44).

  Then, after “NO” is determined in step S42 or after step S44, the packet transmission process is continued (step S45). More specifically, when step S45 is executed after step S44, the routing packet PKT_RT including the delay table is transmitted, and when step S45 is executed after “NO” is determined in step S42, the delay table is executed. A routing packet PKT_RT that does not contain is transmitted.

  Thereafter, the series of operations ends.

  FIG. 20 is a flowchart for explaining the operation of updating the routing table 21 based on the delay table 230. FIG. 21 is a diagram for explaining the concept of updating the routing table 21. In the following, a case where the wireless device 1 receives the routing packet PKT_RT from the wireless device 2 will be described.

  When a series of operations is started, the wireless device 1 receives the routing packet PKT_RT from the wireless device 2 (step S51). Then, the routing daemon 25 of the wireless device 1 receives the routing packet PKT_RT via the UDP module 23, and determines whether or not the received routing packet PKT_RT includes a delay table (step S52). When it is determined that the routing packet PKT_RT does not include the delay table, the series of operations ends.

  On the other hand, when it is determined in step S52 that the routing packet PKT_RT includes the delay table, the routing daemon 25 of the wireless device 1 reads the delay table 230 from the received routing packet PKT_RT (step S53).

  Thereafter, the routing daemon 25 of the wireless device 1 reads the routing table with the expected delay information of the wireless device 1, that is, the routing table 214 (a kind of routing table 21A) shown in FIG. 21 (step S54).

  Subsequently, the routing daemon 25 of the wireless device 1 updates the routing table 214 with reference to the delay table 230 and creates the routing table 215 (see FIG. 21) (step S55).

  More specifically, the routing daemon 25 of the wireless device 1 compares the hop number Hop1 of each route in the routing table 214 with the hop number Hop2 of each route in the delay table 230, and the hop number Hop1 is equal to the hop number Hop2. It is determined whether or not they are the same, and it is determined whether or not the next wireless device Next1 of each route in the routing table 214 is the same as the next wireless device Next2 of each route in the delay table 230.

  Then, when the next wireless device Next1 is the same as the next wireless device Next2 and the hop number Hop1 is the same as the hop number Hop2, the routing daemon 25 of the wireless device 1 uses the routing table 214 and the delay table 230. The remaining expected delay is compared to determine whether to update each route.

  In the case illustrated in FIG. 21, the number of hops Hop1 (= “1”) of the route whose destination is the wireless device 2 in the routing table 214 is the number of hops Hop2 (= “” of the route whose destination is the wireless device 2 of the delay table 230. 1 ”), and in the routing table 214 and the delay table 230, the remaining expected delays corresponding to the wireless device 2 that is the transmission destination are both“ 0.0 ”msec. Does not update the route whose destination is the wireless device 2.

  Further, the hop number Hop1 (= “2”) of the route having the wireless device 3 as the transmission destination in the routing table 214 is the hop number Hop2 (= “2”) of the route having the wireless device 3 as the transmission destination in the delay table 230. Since the routing daemon 25 of the wireless device 1 is the same, the expected remaining delay (= “2.4” msec) corresponding to the wireless device 3 in the routing table 214 and the expected remaining delay corresponding to the wireless device 3 in the delay table 230. (= “3.0” msec) is rewritten to update the route with the wireless device 3 as the transmission destination.

  The expected remaining delay (= “2.4” msec) corresponding to the wireless device 3 in the routing table 214 is smaller than the expected remaining delay (= “3.0” msec) corresponding to the wireless device 3 in the delay table 230. Nevertheless, the reason why the remaining expected delay of “2.4” msec is rewritten to the expected remaining delay of “3.0” msec is to create the routing table 215 reflecting the latest delay.

  Further, the hop number Hop1 (= “1”) of the route having the wireless device 4 as the transmission destination in the routing table 214 is greater than the hop number Hop2 (= “2”) of the route having the wireless device 4 as the transmission destination in the delay table 230. Therefore, the routing daemon 25 of the wireless device 1 does not update the route whose destination is the wireless device 4. The same applies to a route that uses the wireless device 5 as a transmission destination.

  Further, the hop number Hop1 (= “3”) of the route having the wireless device 6 as the transmission destination in the routing table 214 is the hop number Hop2 (= “3”) of the route having the wireless device 6 as the transmission destination in the delay table 230. Since the next wireless device Next1 (= wireless device 4) in the routing table 214 is different from the next wireless device Next2 (= wireless device 2) in the delay table 230, the routing daemon 25 of the wireless device 1 The route whose destination is the device 6 is not updated.

  The routing daemon 25 of the wireless device 1 updates the routing table 214 with reference to the delay table 230 and creates the routing table 215 by the method described above.

  Then, after “NO” in step S52 or step S55, the series of operations ends.

  FIG. 22 is another diagram for explaining the concept of updating the routing table 21. The routing daemon 25 of the wireless device 1 may update the routing table 214 based on the delay table 230 and create the routing table 216 according to the flowchart shown in FIG.

  In this case, the routing daemon 25 of the wireless device 1 compares the remaining expected delays in the routing table 214 and the delay table 230 when the hop number Hop1 of the routing table 214 is the same as the hop number Hop2 of the delay table 230. Decide whether to update the route.

  The update of the route with the wireless devices 2, 3, 4, and 5 as the transmission destination is the same as that shown in FIG.

  The hop number Hop1 (= “3”) of the route having the wireless device 6 as the transmission destination in the routing table 214 is the same as the hop number Hop2 (= “3”) of the route having the wireless device 6 as the transmission destination in the delay table 230. Therefore, the routing daemon 25 of the wireless device 1 sets the remaining expected delay (= “5.6” msec) corresponding to the wireless device 6 in the routing table 214 to the remaining expected delay (= Compared to “5.5” msec).

  Then, the routing daemon 25 of the wireless device 1 has a remaining expected delay of “5.5” msec smaller than the expected remaining delay of “5.6” msec. Are stored in the “next wireless device” and the “remaining expected delay” of the route whose destination is the wireless device 6 in the routing table 214. The routing table 214 is updated, and the routing table 216 is created.

  In this way, when the number of hops in the routing table 214 is the same as the number of hops in the delay table 230, by updating the routing table 214 with a route having a smaller remaining expected delay, the remaining expected to the destination The delay can be shortened, and the packet PKT can be transmitted to the transmission destination with a margin.

  18 and 19, the creation of the delay table 230 in the wireless device 2 that relays one packet PKT has been described. In the wireless device 2 that relays one packet PKT, N delays x (1) and x (2) of the wireless device 2 measured in the wireless device 2 when the one packet PKT is sequentially relayed. ,..., X (N) are averaged to calculate one average delay, and the calculated one average delay is the remaining expected delay corresponding to all the transmission destinations in the routing table 213 (see FIG. 19). To create a delay table 230.

  That is, in the wireless device 2 that relays one packet PKT, not only the remaining expected delay of the route for transmitting the one packet PKT but also the remaining expected delay corresponding to a destination other than the destination of the one packet PKT. In addition, the delay table 230 is created by adding the average delay.

  In the present invention, when relaying n packets PKT1 to PKTn, an average delay is calculated for each transmission destination of each packet, and the calculated n average delays are calculated for n transmission destinations corresponding to n transmission destinations. A delay table is created by adding to the remaining expected delay.

  FIG. 23 is another diagram showing the concept of creating a delay table from the routing table 21. The wireless device 2 relays the five packets PKT1 to PKT5 with the wireless devices 1, 3, 4, 5, and 6 as transmission destinations, respectively. In this case, the wireless device 2 has an average delay of “5.0” msec with respect to the wireless device 1 that is the transmission destination, and an average delay of “6.0” msec with respect to the wireless device 3 that is the transmission destination. And has an average delay of “4.0” msec for the wireless device 4 that is the transmission destination, and an average delay of “2.0” msec for the wireless device 5 that is the transmission destination, It has an average delay of “1.0” msec with respect to the wireless device 6 that is the transmission destination.

  Then, the wireless device 2 adds the average delay of “5.0” msec to the remaining expected delay “0.0” msec corresponding to the wireless device 1 in the routing table 213, and corresponds to the wireless device 3 in the routing table 213. The average delay of “6.0” msec is added to the remaining expected delay “0.0” msec, and “4.0” msec is added to the remaining expected delay “0.0” msec corresponding to the wireless device 4 in the routing table 213. The average delay is added, the average delay of “2.0” msec is added to the remaining expected delay “2.4” msec corresponding to the wireless device 5 in the routing table 213, and the remaining corresponding to the wireless device 6 in the routing table 213 The delay table 230A is created by adding the average delay of “1.0” msec to the expected delay “2.5” msec.

  Thus, in the present invention, when each of the wireless devices 1 to 6 transmits or relays a plurality of packets, the average delay calculated for each transmission destination of each packet is added to the remaining expected delay corresponding to each transmission destination. To create a delay table.

  In the present invention, a plurality of average delays calculated for each transmission destination of each packet are further averaged to obtain one average delay, and the obtained average delay is used in FIG. 18 and FIG. The delay table 230 may be created by the method described.

  When each of the wireless devices 1 to 6 is a transmission source, it generates n packets according to the flowchart shown in FIG. 11, determines the transmission schedule of the generated n packets, and n according to the flowchart shown in FIG. Packets are transmitted in the order determined by the transmission schedule.

  When each of the wireless devices 1 to 6 is a relay that relays a packet between a transmission source and a transmission destination, the wireless devices 1 to 6 receive n packets according to the flowchart shown in FIG. And the n packets are transmitted in the order determined by the transmission schedule according to the flowchart shown in FIG.

  As a result, each of the wireless devices 1 to 6 relatively delays a packet having a relatively large allowable delay, relatively accelerates a packet having a relatively small allowable delay, and puts each packet within a corresponding allowable delay. Send.

  Therefore, the requested QoS can be stably satisfied.

[Modification]
(1) Scheduling When the routing table 21 includes the routing table 21A (see (a) of FIG. 6), the allowable delay is calculated by the equation (1) using the remaining expected delay included in the routing table 21A.

  In the present invention, when the routing table 21 includes the routing table 21B (see (b) of FIG. 6), the number of hops is read from the routing table 21B and the remaining expected delay is multiplied by the constant C. An allowable delay may be calculated using the calculated remaining expected delay.

  That is, in the present invention, the allowable delay may be calculated by the equation (2).

  FIG. 24 is another flowchart for explaining the operation from the generation of a packet to the scheduling of the transmission order. FIG. 25 is a first example of the routing table 21B shown in FIG.

  The flowchart shown in FIG. 24 is the same as the flowchart shown in FIG. 11 except that step S6 of the flowchart shown in FIG. 11 is replaced with step S6A.

  After step S5, the IP output unit 204 of the IP module 20 detects the number of hops corresponding to the transmission destination set in step S5 with reference to the routing table 221 (see FIG. 25), and sets the detected number of hops. Multiply by a constant C to calculate the remaining expected delay.

  Then, the IP output unit 204 calculates the allowable delay by substituting the accumulated delay delay initialized in Step S3, the maximum allowable delay initialized in Step S4, and the calculated remaining expected delay into Expression (2). (Step S6A).

  Thereafter, steps S8 and S9 described above are executed.

  FIG. 26 is another flowchart for explaining the scheduling operation at the time of packet reception. FIG. 27 is a second example of the routing table 21B shown in FIG.

  The flowchart shown in FIG. 26 is the same as the flowchart shown in FIG. 13 except that step S17 of the flowchart shown in FIG. 13 is replaced with step S17A.

  After step S16, the IP output unit 204 of the IP module 20 detects the number of hops corresponding to the transmission destination read in step S16 with reference to the routing table 222 (see FIG. 27), and the detected number of hops. Is multiplied by a constant C to calculate the remaining expected delay.

  Then, the IP output unit 204 calculates the allowable delay by substituting the accumulated delay delay read in step S13, the maximum allowable delay read in step S15, and the calculated remaining expected delay into equation (2). (Step S17A).

  Thereafter, steps S18 and S19 described above are executed.

  Thus, in the present invention, the remaining expected delay may be calculated using the number of hops to the transmission destination, and the allowable delay in each wireless device may be calculated using the calculated remaining expected delay. That is, in the present invention, the allowable delay in each wireless device may be calculated using the number of hops to the transmission destination.

  The method of calculating the allowable delay in each wireless device using the number of hops does not need to broadcast the average delay in each wireless device to the surroundings, so it is not necessary to calculate the average delay, reducing the burden on each wireless device it can. In addition, an allowable delay in each wireless device can be calculated using a conventional routing table.

(2) Average delay In the above description, it has been described that the average delay in each of the wireless devices 1 to 6 is calculated by the equation (3). However, in the present invention, the present invention is not limited to this. Also good.

なお、ｗ_ｉは、データｘ（ｉ）の重みである。

Note that w _i is the weight of the data x (i).

  That is, in the present invention, the average delay may be calculated by weighted average.

  In the present invention, the average delay may be calculated by the following equation.

式（５）において、ｙ（ｊ−１）は、平均遅延を表す。従って、式（５）は、既に演算された平均遅延ｙ（ｊ−１）と、新たに演算された遅延ｘ（ｊ）との平均を演算して平均遅延ｙ（ｊ）を求める方法である。

In equation (5), y (j−1) represents the average delay. Therefore, Expression (5) is a method for calculating the average of the already calculated average delay y (j−1) and the newly calculated delay x (j) to obtain the average delay y (j). .

  When calculating the average delay according to equation (5), it is only necessary to hold the already calculated average delay y (j−1), so that the average delay is simpler than when calculating the average delay according to equation (3). Can be calculated.

  Further, in the present invention, the average delay may be calculated by the following equation.

なお、ｗ_ｍｉｄは、重みの中間値である。

Note that w _mid is an intermediate value of weights.

  In Expression (6), z (j−1) represents an average delay calculated by weighted average. Therefore, the equation (6) is obtained by calculating the average by the weighted average of the average delay z (j−1) already calculated by the weighted average and the newly calculated delay x (j), and calculating the average delay z (j ).

When calculating the average delay according to the equation (6), it is only necessary to hold the average delay z (j−1) and the weight intermediate value w _mid that have already been calculated, so the average delay is calculated according to the equation (4). The average delay can be calculated more easily than in the case.

  Further, in the present invention, the average delay may be calculated by the following equation.

なお、αは、ゲインであり、固定値からなる。そして、αは、０＜α＜１の範囲に設定される。

Α is a gain and is a fixed value. Α is set in a range of 0 <α <1.

  In equation (7), y (j−1) represents the average delay calculated by the exponential moving average. Then, an exponential function is established between (1−α) which is the weight of the newly calculated delay x (j) and j. As described above, the exponential moving average is an average calculation in which an exponential relationship is established between (1−α) which is the weight of the newly calculated delay x (j) and the number of times j of the calculation of the delay x (j). Is the method.

  Accordingly, the equation (7) is obtained by calculating the average by the exponential moving average of the average delay y (j−1) already calculated by the exponential moving average and the newly calculated delay x (j). This is a method for obtaining (j).

  When calculating the average delay according to the equation (7), the average delay y (j) is greatly influenced by the exponential moving average y (j−1) that has already been calculated as α is closer to “1”. The closer to ", the greater the influence of the newly calculated delay x (i).

  As described above, in the present invention, the average delay may be calculated according to any of the equations (3) to (7).

  In the above description, it has been described that a linear relationship (straight line k1) is established between the priority and the allowable delay, as shown in FIG. 8, but the present invention is not limited to this, and the priority and the allowable delay. An inversely proportional relationship may be established with the delay.

  In the present invention, the IP module 20 (IP output unit 204) that calculates the allowable delay according to the formula (1) or the formula (2) constitutes an “allowable delay calculation means”.

  The LLC module 19 that determines the transmission schedule of the packets PKT1 to PKT5 based on the allowable delays delay_allow1 to delay_allow5 constitutes “scheduling means”.

  Furthermore, the LLC module 19, the MAC module 17, and the wireless interface 16 that transmit the packets PKT 1 to PKT 5 according to the determined scheduling constitute “transmission means”.

  Furthermore, the communication control unit 15 that holds the routing table 21 in the Internet layer constitutes “table holding means”.

  Furthermore, the IP module 20 (IP output unit 204) that calculates the delay delay_u by subtracting the arrival time arriv_time from the current time system_time constitutes a “delay calculating means”.

  Further, the IP module 20 (IP output unit 204) that adds the delay delay_u to the cumulative delay delay, and the MAC module 17 that writes the addition result by the IP module 20 (IP output unit 204) in the cumulative delay unit 322 are “update means”. Configure.

Furthermore, the memory 206 that stores x ₂ (1), x ₂ (2),..., X ₂ (N−1) and the like shown in FIG.

  Further, the IP module 20 (IP output unit 204) that calculates the average delay constitutes “average delay calculation means”.

  Further, the routing daemon 25 that creates the delay tables 230 and 230A constitutes “delay table creation means”.

  Further, the routing daemon 25 that updates the routing table 21A based on the delay tables 230 and 230A constitutes “table updating means”.

  According to the embodiment of the present invention, each of the wireless devices 1 to 6 constituting the wireless network system 10 has n packets so that wireless communication is performed within the maximum allowable delay between the transmission source and the transmission destination. The n allowable delays in the wireless devices 1 to 6 are calculated, and n packets are transmitted within the corresponding allowable delays based on the calculated n allowable delays. A transmission schedule is determined, and n packets are transmitted according to the determined transmission schedule.

  Therefore, according to the present invention, the required QoS can be stably satisfied.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a wireless device that can stably satisfy a required QoS.

1 is a schematic diagram of a wireless network system using a wireless device according to an embodiment of the present invention. It is a schematic block diagram which shows the structure of the radio | wireless apparatus shown in FIG. It is a block diagram of a packet. It is a block diagram of an IP header. It is a block diagram of a TCP header and a UDP header. It is a block diagram of the routing table shown in FIG. It is a functional block diagram of the IP module shown in FIG. It is a figure which shows the relationship between an allowable delay and a priority. It is a correspondence figure of time and an identification number. It is a figure which shows the relationship between an application and the maximum allowable delay. It is a flowchart for demonstrating operation | movement from generation | occurrence | production of a packet to scheduling of a transmission order. It is a 1st example of the routing table shown to (a) of FIG. It is a flowchart for demonstrating the operation | movement of the scheduling at the time of packet reception. It is a 2nd example of the routing table shown to (a) of FIG. It is a flowchart for demonstrating the operation | movement from the packet transmission instruction | indication to packet transmission. It is a recording format of past delay in one wireless device. 3 is a flowchart for explaining the operation of the MAC module shown in FIG. 2. It is a flowchart for demonstrating operation | movement of preparation of a delay table in each radio | wireless apparatus, and transmission. It is a figure which shows the concept which produces a delay table from a routing table. It is a flowchart for demonstrating the operation | movement which updates a routing table based on a delay table. It is a figure for demonstrating the concept of the update of a routing table. It is another figure for demonstrating the concept of the update of a routing table. It is another figure which shows the concept which produces a delay table from a routing table. It is another flowchart for demonstrating operation | movement from generation | occurrence | production of a packet to scheduling of a transmission order. It is a 1st example of the routing table shown in FIG.6 (b). It is another flowchart for demonstrating the operation | movement of the scheduling at the time of packet reception. It is a 2nd example of the routing table shown in FIG.6 (b).

Explanation of symbols

  1 to 6 wireless devices, 10 wireless network systems, 11 antennas, 12 input units, 13 output units, 14 user applications, 15 communication control units, 16 wireless interface modules, 17 MAC modules, 18 buffers, 19 LLC modules, 20 IP modules 21, 21A, 21B, 211-216, 221, 222 Routing table, 22 TCP module, 23 UDP module, 24 SMTP module, 25 Routing daemon, 31 MAC header, 32 DL header, 33 IP header, 34 TCP header, 35 Data, 36 FCS, 37 UDP header, 201 IP input queue, 202 IP option processing unit, 203 destination identification unit, 204 IP output unit, 205 timer, 206 Memory, 230, 230A delay table, 321 maximum allowable delay unit, 322 cumulative delay unit.

Claims (8)

A wireless device that is autonomously established and constitutes a wireless network in which wireless communication is performed between a transmission source and a transmission destination,
For each of n packets (n is a positive integer) to be transmitted, an allowable delay in the wireless device is calculated so that wireless communication is performed within the maximum allowable delay between the transmission source and the transmission destination. An allowable delay calculating means to perform,
N transmission destinations of the n packets, and n hop numbers each corresponding to the n transmission destinations, each consisting of the number of hops from the wireless device to the transmission destination. Table holding means for holding a routing table including;
An average delay calculating means for executing an average delay process for calculating the average delay in the wireless device for the n packets;
The calculated n average delays are added to n remaining expected delays corresponding to the n transmission destinations and each of which is an expected delay between the wireless device and the transmission destination. A delay table creating means for creating a delay table by
Table updating means for updating the routing table based on the delay table transmitted from another wireless device;
Route determining means for determining n routes for transmitting the n packets to the n destinations based on the routing table;
Scheduling means for determining a transmission schedule of the n packets based on the calculated n allowable delays so that the n packets are transmitted within each corresponding allowable delay;
Transmitting means for transmitting the n packets along the n paths based on the determined transmission schedule ;
The said table update means is a radio | wireless apparatus which updates the said routing table when the 1st hop number contained in the said delay table and the 2nd hop number contained in the said routing table are the same . The allowable delay calculating means sets the allowable delay between the transmission source and the transmission destination determined according to the type of packet to be transmitted as the maximum allowable delay, and between the transmission source and the wireless device. when the accumulated delay delays in, by subtracting the accumulated delay and the remaining expected delay from the maximum allowable delay for calculating each of said n permissible delay, the wireless device according to claim 1. The routing table is provided corresponding to the n destinations, and n remaining expected delays each consisting of a remaining expected delay that is an expected delay between the wireless device and the destination Further including
Before SL permissible delay calculating means, said from the allowable subject to packet operations delayed read a maximum allowable delay and the accumulated delay, the remainder expected delay corresponding to the destination of the packet to be operational in the allowable delay And an allowable delay calculation process for calculating the allowable delay of the packet subject to the calculation of the allowable delay based on the read maximum allowable delay, the cumulative delay, and the remaining expected delay. The radio apparatus according to claim 2, wherein the radio apparatus executes n packets and calculates the n allowable delays. Before SL permissible delay calculating means, the allowable reading the number of hops to the destination subject to packet operations of the delay from the routing table, the transmission from the wireless device by multiplying a constant number of hops thus read out The remaining expected delay, which is the expected delay until now, is calculated, the maximum allowable delay and the accumulated delay are read from the packet that is the target of the allowable delay calculation, and the read maximum allowable delay and the read An allowable delay calculation process for calculating the allowable delay of the packet subject to the calculation of the allowable delay based on the accumulated delay and the calculated remaining expected delay is executed for the n packets, and the n allowable delays are performed. The wireless device according to claim 2, wherein Delay calculating means for calculating a self-delay that is a delay in the wireless device of each packet;
Update processing for reading the accumulated delay from the packet to be transmitted, adding the calculated self-delay to the read accumulated delay, writing the addition result to the packet to be transmitted, and updating the accumulated delay Update means for executing on the number of packets,
5. The transmission device according to claim 2, wherein, when transmitting a packet based on the transmission schedule, the transmission unit updates the accumulated delay included in the packet, and transmits the packet including the updated accumulated delay. The wireless device according to item 1. Delay calculating means for calculating a self-delay that is a delay in the wireless device of each packet;
For each of the previous SL n packets, each is already delay in the radio apparatus of the transmitted packet, and a self-delay which are sequentially calculated by the delay calculating means when the packet is transmitted Storage means for storing k (k is a positive integer) actual self-delays
The average delay calculating means calculates an average delay based on the self delay calculated by the delay calculating means when each packet is transmitted and the k actual self delays stored in the storage means. The wireless device according to any one of claims 1 to 3. Delay calculating means for calculating a self-delay that is a delay in the wireless device of each packet;
For each of the previous SL n packets, each is already delay in the radio apparatus of the transmitted packet, and a self-delay which are sequentially calculated by the delay calculating means when the packet is transmitted Storage means for storing the previous average delay calculated by the average delay calculation means,
The average delay calculating means calculates a new average delay based on the self-delay calculated by the delay calculating means when each packet is transmitted and the previous average delay stored in the storage means. The wireless device according to any one of claims 1 to 3. When the first remaining expected delay included in the delay table is smaller than the second remaining expected delay included in the routing table, the table update unit determines the second remaining expected delay as the first remaining expected delay. The wireless device according to claim 1 , wherein the routing table is updated by rewriting with a delay.

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