JP5337230B2 - Communication control device, wireless communication device, communication control method, and wireless communication method - Google Patents

Description

  In the present invention, a plurality of different wireless communication paths can be used, and the bandwidth that is lacking in one wireless communication path is supplemented by using other wireless communication paths with respect to the required bandwidth of the application having real-time characteristics to be used. The present invention relates to a novel communication control device, a wireless communication device, a communication control method, and a wireless communication method that can execute communication.

  For example, in a wireless communication network using an Internet protocol (IP) group (hereinafter, appropriately abbreviated as “wireless IP network”), so-called mobile IP is defined in order to improve mobility of a wireless communication device (for example, Non-patent document 1).

  In the mobile IP, a care-of IP address (Care of Address) that is dynamically assigned according to the position of the wireless communication device is used.

C. Perkins, “IP Mobility Support (RFC2002)”, [online], October 1996, IETF, [March 15, 2006 search], Internet <URL: http: //www.ietf.org / rfc /rfc2002.txt>

  By the way, recently, an environment in which a wireless communication apparatus can use a plurality of wireless IP networks (for example, a mobile phone network and a wireless LAN network) is being provided.

  In such an environment, it is conceivable to perform communication by complementing a bandwidth that is insufficient in one wireless communication path with another wireless communication path with respect to a requested bandwidth of an application having real-time characteristics to be used. . In this case, it is assumed that a transmission path ratio change message for supplementing the bandwidth that is insufficient in one wireless communication path with another wireless communication path is transmitted and received between the communication control apparatus and the wireless communication apparatus. .

  There is a time from when the change message is transmitted until it reaches the other party (communication control device or wireless communication device), and another time after the transmission rate is changed until the packet is transmitted from the other party and received. The transmission path ratio from the other party changes with a delay of the sum of these two times. Since the sum of these times changes due to fluctuations in the communication bandwidth due to changes in the wireless status, retention of the transmission buffer on the transmission side, etc., the receiving side must accurately detect when the transmission path ratio has changed. I can't.

  When the reception bandwidth is measured with a margin of a predetermined time (for example, 500 ms) after the change message is transmitted and the transmission path ratio is calculated, the reception bandwidth is not measured after the transmission path ratio is actually changed. As a result, there is wasted time until the reception band is measured after the transmission rate is actually changed. Therefore, it is impossible to respond immediately when the traffic state changes rapidly.

  FIG. 6 is a diagram for explaining the case where the reception bandwidth is measured with a margin of a predetermined time (for example, 500 ms) after the change message is transmitted, and the transmission path ratio is calculated. In this case, only one of the main route and the sub route is displayed, and the measurement interval from the transmission band request being transmitted as the change message after the measurement period of 500 ms to the next measurement time is 500 ms. The black circles in FIG. 6 indicate the timing at which the first packet transmitted in the requested transmission band is received. When there is no problem in the communication state, the time (CDMA2000 1x EVDO) is usually about RTT (Round Trip Time). In this case, it is a little less than 200 ms, and in WiMAX, it is 100 ms or less.) For this reason, a large time lag occurs between the black circle and the next measurement period.

  In addition, even if the transmission buffer is stagnated due to deterioration of the radio condition on either the main route or the sub route, or sudden congestion of traffic, such retention cannot be detected at least until the next measurement period. . If the communication band is suddenly narrowed due to stagnation, the receiving side will confirm the decrease in the communication band after measuring the reception band and notify the ratio of the transmission path according to the communication band. Packets transmitted through a communication path whose bandwidth is sharply narrowed are accumulated in a transmission buffer, and as a result, packets received via a communication path whose bandwidth is sharply narrowed may have a large delay.

  Specifically, if the transmission buffer or the like stays in one of the main route and the slave route, if the packet is continuously sent to the route without noticing the stay on the transmission side, the staying amount increases. Therefore, a large delay occurs in all the staying packets.

  For example, if G711 (about 90 kbps assuming UDP (User Datagram Packet) tunneling) is transmitted at a rate of 50% on one of the main route and the sub route, the transmission buffer has about 90 kbps. Packets accumulate at a rate of × 0.5≈45 kbps (25 packets).

  When the wireless communication band drops to 10 kbps from this state, only about 6 packets can be transmitted in 1 second, and therefore about 19 packets stay in the transmission buffer every second. Packets staying in the transmission buffer are sequentially transmitted, but all the packets after the packet at the initial stage of staying are discarded as underrun by the receiving side application.

  An object of the present invention is to provide a communication control device, a wireless communication device, and a wireless communication device capable of reducing the influence of the retention of the transmission buffer caused by the deterioration of the wireless state in one of the main route and the secondary route or the sudden congestion of traffic. A communication control method and a wireless communication method are provided.

According to the present invention, a communication control apparatus according to claim 1 is provided.
A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control device for controlling communication between the wireless communication device and a communication destination,
Receiving means for receiving bandwidth information of each wireless communication path calculated on the wireless communication device side from the wireless communication device;
Transmission control means for allocating and transmitting packets to each wireless communication path based on the band information received by the receiving means;
Transmission ratio adding means for adding information on the transmission ratio of each wireless communication path to a packet transmitted by the transmission control means is provided.

The communication control device according to claim 2 of the present invention comprises:
A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control device for controlling communication between the wireless communication device and a communication destination,
Receiving means for receiving a packet to which information of a transmission rate of each wireless communication path transmitted by the wireless communication device is added;
Measuring means for measuring the reception bandwidth of each wireless communication path based on the received packet;
Based on the reception band information measured by the measurement unit after the reception unit receives the packet with the transmission rate information added thereto, information on the transmission rate of the transmission path of the wireless communication device is obtained. It is characterized by comprising notifying means for notifying.

According to the present invention, there is provided a communication control device according to claim 3.
Based on the packet received by the receiving means, further comprising a detecting means for detecting retention of transmission packets of the wireless communication device in each wireless transmission path,
When the detection unit detects the stay of the transmission packet, the notification unit notifies the transmission rate to be reduced.

According to the present invention, there is provided a wireless communication apparatus according to claim 4.
A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication device that wirelessly communicates with a communication destination via the communication control device,
Receiving means for receiving the bandwidth information of each wireless communication path calculated on the communication control device side from the communication control device;
Transmission control means for allocating and transmitting packets to each wireless communication path based on the band information received by the receiving means;
Transmission ratio adding means for adding information on the transmission ratio of each wireless communication path to a packet transmitted by the transmission control means is provided.

According to the present invention, there is provided a wireless communication apparatus according to claim 5.
A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication device that wirelessly communicates with a communication destination via the communication control device,
Receiving means for receiving a packet to which information on a transmission ratio of each wireless communication path transmitted by the communication control device is added;
Measuring means for measuring the reception bandwidth of each wireless communication path based on the received packet;
Based on the reception band information measured by the measurement unit after the reception unit receives the packet with the transmission rate information added thereto, information on the transmission rate of the transmission path of the communication control device is obtained from the communication control device. It is characterized by comprising notifying means for notifying.

According to the present invention, there is provided a wireless communication apparatus according to claim 6.
Based on the packet received by the receiving means, further comprising a detecting means for detecting retention of transmission packets of the communication control device in each wireless transmission path,
When the detection unit detects the stay of the transmission packet, the notification unit notifies the transmission rate to be reduced.

The communication control method of claim 7 according to the present invention comprises:
A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control method for controlling communication between the wireless communication device and a communication destination,
Band information of each wireless communication path calculated on the wireless communication device side is received from the wireless communication device,
Based on the received bandwidth information, packets are allocated to each wireless communication path and transmitted.
Information on a transmission ratio of each wireless communication path is added to the packet to be transmitted.

The communication control method of claim 8 according to the present invention comprises:
A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control method for controlling communication between the wireless communication device and a communication destination,
Receiving a packet to which information of a transmission rate of each wireless communication path transmitted by the wireless communication device is added;
Measure the reception bandwidth of each wireless communication path based on the received packet,
Information on the transmission rate of the transmission path is notified to the wireless communication device based on information of a reception band measured after receiving a packet with the transmission rate information added thereto.

The communication control method of claim 9 according to the present invention comprises:
When it is detected based on the received packet that the transmission packet of the wireless communication apparatus is in each wireless transmission path, the transmission ratio is notified to be reduced.

The wireless communication method of claim 10 according to the present invention comprises:
A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication method for wirelessly communicating with a communication destination via the communication control device,
The bandwidth information of each wireless communication path calculated on the communication control device side is received from the communication control device,
Based on the received bandwidth information, packets are allocated to each wireless communication path and transmitted.
Information on a transmission ratio of each wireless communication path is added to the packet to be transmitted.

The wireless communication method of claim 11 according to the present invention comprises:
A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication method for wirelessly communicating with a communication destination via the communication control device,
Receiving a packet to which information of a transmission ratio of each wireless communication path transmitted by the communication control device is added;
Measure the reception bandwidth of each wireless communication path based on the received packet,
The communication control device is notified of information related to the transmission rate of the transmission path of the communication control device based on information of a reception band measured after receiving the packet with the transmission rate information added thereto. .

The wireless communication method of claim 12 according to the present invention comprises:
Based on the received packet, when it is detected that the transmission packet of the communication control device is in each wireless transmission path, a notification is made to reduce the transmission ratio.

  According to the present invention, the reception band of the wireless communication path can be measured immediately upon reception of the packet with the transmission rate information added thereto. Therefore, it is possible to immediately cope with the retention of the transmission buffer caused by the sudden congestion of the transmission buffer. Therefore, the influence of the retention of the transmission buffer can be reduced.

1 is an overall schematic configuration diagram of a communication system according to the present embodiment. It is a functional block block diagram of the switching server and MN shown in FIG. It is a figure which shows the transmission band message in the transmission side of a mobile node and a switching server. It is a figure for demonstrating the measurement interval of the zone | band measurement time in a main path | route and a secondary path | route. It is a flowchart of operation | movement of this Embodiment. It is a figure for demonstrating the case where a reception zone | band is measured in view of the allowance of predetermined time after transmitting a change message, and the transmission path | route ratio is calculated.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an overall schematic configuration diagram of a communication system 1 according to the present embodiment. As shown in FIG. 1, the communication system 1 includes a wireless IP network 10A and a wireless IP network 10B. The wireless IP network 10A is an IP network that can transmit IP packets. In the wireless IP network 10A, the care-of IP address A1 is dynamically assigned to the MN 300 in accordance with the position of the wireless communication device 300 (hereinafter abbreviated as MN 300). In the present embodiment, the wireless IP network 10A is a mobile phone network that uses EDVO (specifically, HRPD that is a 3GPP2 standard) as a wireless communication method.

  The wireless IP network 10B can transmit IP packets in the same manner as the wireless IP network 10A. In the wireless IP network 10B, the care-of IP address A2 is assigned to the MN 300. In the present embodiment, the wireless IP network 10B uses mobile WiMAX compliant with the IEEE 802.16e standard as a wireless communication method.

  The care-of IP address A1 is given from the wireless IP network 10A when the MN 300 is connected to the wireless IP network 10A. Similarly, the care-of IP address A2 is given from the wireless IP network 10B when the MN 300 is connected to the wireless IP network 10B.

  In the present embodiment, the care-of IP address A1 and the care-of IP address A2 are associated with the home IP address AH (virtual address).

  The switching server 100 and the MN 300 can execute communication using the wireless IP network 10A and the wireless IP network 10B simultaneously. Specifically, the switching server 100 and the MN 300 perform transmission / reception of IP packets using the wireless IP network 10A as a main route. When the bandwidth (transfer rate) of the main route is insufficient, the switching server 100 and the MN 300 follow the wireless IP network 10B. Using this as a route, the insufficient bandwidth is supplemented with a slave route. The slave path is not limited to one of the wireless IP networks 10B, and a plurality of available wireless IP networks may be used simultaneously.

  The wireless IP network 10A and the wireless IP network 10B are connected to the Internet 20. The switching server 100 is connected to the Internet 20. The switching server 100 constitutes a communication control device that controls a wireless communication path with the MN 300, and can transmit an IP packet to the MN 300 via the wireless IP network 10A and also via the wireless IP network 10B. Thus, an IP packet can be transmitted to the MN 300.

  The switching server 100 has a VPN router function for performing routing processing of IP packets, and by establishing a tunnel by VPN (IPSec) between the MN 300 and the switching server 100, virtualization of the OSI third layer To secure the IP mobility of the MN 300.

  That is, in the present embodiment, unlike mobile IP (for example, RFC 2002), the MN 300 has a main route set via the wireless IP network 10A and a sub route set via the wireless IP network 10B. The communication with the communication destination (specifically, the IP telephone terminal 40) can be executed using both wireless communication paths simultaneously.

  The switching server 100 is connected to the IP telephone terminal 40 via a communication network 10 </ b> C connected to the Internet 20. The IP telephone terminal 40 mutually converts voice signals and VoIP packets, and transmits / receives IP packets.

  Specifically, the switching server 100 (communication control device) receives an IP packet (VoIP packet) transmitted from the MN 300 (wireless communication device) to the IP telephone terminal 40 (communication destination) at a predetermined cycle (20 ms). Then, the IP phone terminal 40 receives the IP packet (VoIP packet) transmitted from the IP phone terminal 40 to the MN 300 at a predetermined cycle (20 ms) and relays it to the MN 300.

  Next, the functional block configuration of the communication system 1 will be described. Specifically, the functional block configurations of the switching server 100 and the MN 300 included in the communication system 1 will be described with reference to FIG. Hereinafter, portions related to the present invention will be mainly described. Therefore, it should be noted that the switching server 100 and the MN 300 may include a logical block (power supply unit or the like) that is not illustrated or omitted in description, which is essential for realizing the function as the device.

  As shown in FIG. 2, the switching server 100 includes a reception interface unit (A I / F A) 101Rx, a reception interface unit (I / F B) 103Rx, a reception interface unit (I / FC) 105Rx, a transmission interface unit ( I / F A) 101Tx, transmission interface unit (I / F B) 103Tx, transmission interface unit (I / FC) 105Tx, transmission band for receiving a packet to which information on a transmission ratio is added and a transmission unit as a notification unit A notification analysis unit 107, a reception band measurement unit 109 as a measurement unit, a transmission band calculation unit 111, a transmission path control unit 113 as a communication control unit and a transmission ratio addition unit, and a monitoring timer 115 are provided.

  The reception interface unit 101Rx and the transmission interface unit 101Tx constitute a communication interface unit corresponding to the wireless IP network 10A. For example, the reception interface unit 101Rx and the transmission interface unit 101Tx are configured by 1000BASE-T defined by IEEE 802.3ab, connected to the Internet 20, and It is connected to the network 10A.

  Similarly, the reception interface unit 103Rx and the transmission interface unit 103Tx constitute a communication interface unit corresponding to the wireless IP network 10B. For example, the reception interface unit 103Rx and the transmission interface unit 103Tx are configured by 1000BASE-T defined by IEEE 802.3ab and connected to the Internet 20. Are connected to the wireless IP network 10B.

  The reception interface unit 105Rx and the transmission interface unit 105Tx constitute a communication interface unit corresponding to the communication network 10C, and are connected to the Internet 20 and used to execute communication with the IP telephone terminal 40.

  In the switching server 100, three IFs of a route A, a route B, and a route C are shown, but these may be one I / F. In this case, route A, route B, and route C are identified based on the destination and source address of the input IP packet.

  The transmission band notification analyzing unit 107 analyzes the IP packet including the transmission band request from the IP packets received by the reception interface units 101Rx and 103Rx, and determines the transmission band notified from the mobile note 300 as the transmission path control unit 113. And the transmission band field included in the received IP packet is monitored, and the time from when the transmission band request is transmitted to the mobile node 100 until the arrival of the IP packet reflecting the transmission band is measured. .

  The reception band measuring unit 109 measures the reception band in the route A and the route B according to the flow rate of the IP packet received through the route A and the route B, and notifies the transmission band calculation unit 111 of the measured reception band.

  The transmission band calculation unit 111 calculates the requested transmission band from the mobile node 300 from the notified reception band, and notifies the transmission path control unit 113 of the calculated request transmission band. The transmission path control unit 113 distributes RTP (Real-time Transport Protocol) packets sent through the reception interface unit 105Rx to the path A and the path B based on the transmission band notified from the transmission band notification analysis unit 111. When a transmission bandwidth request to be notified to the mobile node 300 is notified from the transmission bandwidth calculation unit 111, a packet including the transmission bandwidth request is transmitted to the mobile node 300. The monitoring timer 115 measures the measurement time of the reception band measuring unit 109.

  In addition to the above functions, the switching server 100 according to the present embodiment has an order of IP packets transmitted and received between the MN 300 and the IP telephone terminal 40 via the wireless IP network 10A and the wireless IP network 10B. Is also checked using a sequence number (SN) of RTP (real-time transport protocol) included in the VoIP packet. The switching server 100 also has a function of acquiring statistical information (for example, packet loss, throughput, jitter buffer underrun count and overrun count) of the relayed IP packet and transmitting the acquired information to the MN 300. Yes.

  Further, the switching server 100 includes a home IP address AH included in the IP packet transmitted by the IP telephone terminal 40 and a home IP address registered in a home agent (not shown) accessible via the Internet 20. It has a function of collating, so that it is possible to determine which home IP address AH is the home IP address assigned to the MN 300 by which carrier.

  Similar to the switching server 100, the MN 300 can execute communication using the wireless IP network 10A and the wireless IP network 10B simultaneously. Hereinafter, description of functional blocks similar to those of the switching server 100 described above will be omitted as appropriate.

  As shown in FIG. 2, the MN 300 includes a reception interface unit (I / F A) 301Rx, a reception interface unit (I / F B) 303Rx, a transmission interface unit (I / F A) 301Tx, and a transmission interface unit (I / F). B) 303Tx, transmission band notification analysis unit 307, reception band measurement unit 309, transmission band calculation unit 311, transmission path control unit 313, monitoring timer 315, and application 317.

  The reception interface unit 301Rx and the transmission interface unit 301Tx execute wireless communication of a wireless communication method (HRPD that is a 3GPP2 standard) used in the wireless IP network 10A. In the present embodiment, IP packets (VoIP packets) are transmitted / received to / from the IP telephone terminal 40 via the wireless IP network 10A at a predetermined cycle (for example, 20 ms). The reception interface unit 301Rx and the transmission interface unit 301Tx are built in the MN 300 or configured by a wireless communication card.

  The reception interface unit 303Rx and the transmission interface unit 303Tx execute wireless communication conforming to the wireless communication method (mobile WiMAX) used in the wireless IP network 10B, and are similarly incorporated in the MN 300 or a wireless communication card. Consists of.

  The reception interface unit 301Rx and the transmission interface unit 301Tx, and the reception interface unit 303Rx and the transmission interface unit 303Tx are based on the care-of IP address A1 and the care-of IP address A2 assigned to the MN 300 in the radio IP network 10A and the radio IP network 10B. To send and receive IP packets.

  The transmission band notification analyzing unit 307 analyzes the IP packet including the transmission band request from the IP packets received by the reception interface units 301Rx and 303Rx, and determines the transmission band notified from the switching server 100 as the transmission path control unit 313. And the transmission bandwidth field included in the received IP packet is monitored, and the time from when the transmission bandwidth request is transmitted to the switching server 100 until the arrival of the IP packet reflecting the transmission bandwidth is measured. .

  The reception band measuring unit 309 measures the reception band in the route A and the route B according to the flow rate of the IP packet received through the route A and the route B, and notifies the transmission band calculation unit 311 of the measured reception band.

  The transmission band calculation unit 311 calculates the requested transmission band from the switching server 100 from the notified reception band, and notifies the transmission path control unit 313 of the calculated request transmission band. The transmission path control unit 313 distributes the RTP packet sent from the application 317 to the path A and the path B based on the transmission band notified from the transmission band notification analysis unit 311, and from the transmission band calculation unit 311 to the switching server 100. When a transmission bandwidth request to be notified is notified, a packet including the transmission bandwidth request is transmitted to the switching server 100. The monitoring timer 315 measures the measurement time of the reception band measuring unit 309.

  The application 317 is a bidirectional real-time application such as VoIP, for example. In FIG. 2, an application 317 is included in the mobile node 300, but the mobile node 300 is operated as a router, and an external PC (Personal Computer) is connected through a third I / F by Ethernet (registered trademark), wireless LAN, or the like. It can also be arranged.

  Note that the mobile node 300 according to the present embodiment uses the RTP sequence number (SN) included in the VoIP packet as the order of the IP packets transmitted / received to / from the IP telephone terminal 40, similarly to the switching server 100. It also has a function to check.

  FIG. 3 is a diagram illustrating a transmission band message on the transmission side of the mobile node and the switching server. Communication between the mobile node 300 (or a PC following the mobile node) and the IP telephone terminal 40 is performed by tunneling between the mobile node 300 and the switching server 100.

  The VoIP packet before tunneling is shown in FIG. 3A. On the transmission side, when performing tunneling, the transmission band is included in the packet in order to notify the current transmission band of the IP packet to be transmitted.

  FIG. 3B shows a case where a transmission band is added before the inner IP header of tunneling. In the case of a real-time application such as VoIP, since about 50 packets are transmitted per second, it is sufficient that the transmission band is an integer of about 0 to 100%. Even if the transmission band is added, the maximum is 1 byte. It only increases to a certain extent.

  FIG. 3C shows a case where the inner IP header and UDP header are replaced with a label and a transmission band. When VoIP is performed between the mobile node 100 and the IP telephone terminal 40, the IP header and the UDP header are not changed except for the checksum. Therefore, by binding the IP header and the UDP header to the label between the switching server 100 and the mobile node 300, the header reduction effect can be obtained and the transmission band can be notified.

  When the binding information is 2 bytes, the 28-byte IP header and UDP header can be compressed into binding information and a transmission band of about 3 bytes. If a UDP checksum is used, the UDP checksum can be further added or recalculated at the receiving end to be loaded.

  Here, a case has been described in which a communication band is included in a packet on the transmission side, but a transmission band may be inserted in a VoIP packet in the same manner on the transmission band request transmission side.

  FIG. 4 is a diagram for explaining the measurement interval of the band measurement time in the main route and the sub route. In the main route (for example, route A), the reception bandwidth measuring means 109 and 309 measure the reception bandwidth for the time T_mes, respectively, and the transmission route control means 113 and 313 request the mobile node 300 or the switching server 100 for the transmission bandwidth. Send.

  After that, when the IP packet according to the transmission bandwidth request arrives at the switching server 100 or the mobile node 300 after the time T_p1 has elapsed since the transmission bandwidth request was transmitted on the main route, the reception bandwidth measurement units 109 and 309 respectively The reception band is measured again for a time T_mes from the time when the IP packet arrives, and a transmission band request is transmitted to the mobile node 300 or the switching server 100 based on the measurement result.

  When different radio systems are used, since the RTT and the communication band are generally different between the main route and the sub route, the transmission route request is transmitted to the switching server 100 or the mobile node 300 in the sub route (for example, the route B). The time T_p2 at which the first IP packet according to the new transmission rate arrives is different from the time T_p1. In the slave path, after the first IP packet transmitted at a new rate is received by the switching server 100 or the mobile node 300, the reception band measuring means 109 and 309 receive only during the time T_mes- (T_p2-T_p1). Measure bandwidth.

  The transmission bandwidth request is made on one or both of the main route and the sub route. On the transmitting side, when transmitting at the transmission rate specified by the receiving side, the received bandwidth can be measured immediately when reception is possible at a new transmission rate by putting the transmission rate in the transmission packet. As a result, there is no wasted time until the reception bandwidth is measured after the transmission rate is actually changed. Therefore, it is possible to respond immediately when the traffic state changes suddenly.

  FIG. 5 is a flowchart of the operation of the present embodiment. In this case, a state in which packet retention does not occur in either the main route or the slave route is defined as a normal state.

  First, the case of a normal state will be described. In FIG. 5A, the transmission bandwidth request (BW_req_1 on the main route and BW_req_2 on the sub route) is transmitted to the other party (switching server 100 or mobile node 300) in the normal state (step S1), and the timer of each route is set to t_1 = The process is started with 0, t_2 = 0, and the process transitions to FIGS. 5B and 5C (step S2). Here, FIG. 5B shows the processing of the main route, and FIG. 5C shows the processing of the sub route.

  In FIG. 5 (b), it is determined whether or not a packet transmitted at a rate of BW_req_1 is received (step S101). When the packet is received, measurement of a reception band is started on the main route, After the measurement period T_mes elapses, it is determined that the main route is in a normal state, and the process proceeds to FIG.

  FIG. 5C shows the process of the secondary path, and determines whether or not the packet transmitted at the rate of BW_req_2 has been received (step S201). The measurement of the band is started, and after the measurement period T_mes- (tp1-tp2) elapses, it is determined that the slave path is in a normal state, and the process transitions to FIG. 5D (step S202).

  In FIG. 5D, it waits for both the main route and the sub route to finish in the normal state (step S301), and when the main route and the sub route are in the normal state and transits to FIG. 5D, measurement is performed during the measurement time. Based on the received bandwidth, the transmission bandwidth request values BW_req_1 ′ and BW_req_2 ′ are calculated for the main route and the slave route, respectively (step S302), and the transmission bandwidth request values BW_req_1 ′ and BW_req_2 ′ are transmitted to the other party (step S302). In step S303, the timers for the main route and the sub route are reset, and the process returns to FIGS. 5B and 5C (step S304). In this way, in the normal state, the above operation is repeated.

  Next, a case where stagnation occurs in either the main route or the sub route will be described. If the packet transmitted at the rate of BW_req_1 is not received in step S101 of FIG. 5B, it is determined whether the time t1 from when the transmission bandwidth request is transmitted to the present time exceeds the threshold t_thresh_1 of the main route. (Step S103). When the threshold value t_thresh_1 is exceeded, it is assumed that a stagnation has occurred, and the transmission request of the main route is reduced to a first non-zero value, for example, 1% (BW_req_1 ″ = 1%), and FIG. In contrast, if the threshold value t_thresh_1 is not exceeded, the process returns to step S101.

  If the packet transmitted at the rate of BW_req_2 is not received in step S201 of FIG. 5C, it is determined whether the time t2 from when the transmission bandwidth request is transmitted to the present time exceeds the threshold t_thresh_2 of the main route. (Step S203). When the threshold value t_thresh_2 is exceeded, it is assumed that a stagnation has occurred, the transmission request of the slave path is reduced to 1% (BW_req_2 ″ = 1%), and the process proceeds to FIG. 5E (step S204). On the other hand, if the threshold value t_thresh_2 is not exceeded, the process returns to step S201.

  When a transition from one of FIGS. 5B and 5C to FIG. 5E occurs, in FIG. 5E, the bandwidth of the path that is not the transition source (the path where no stay has occurred) The recently calculated value is used (step S401), a transmission bandwidth request (BW_req_1 "or BW_req_2") is transmitted to the other party (step S402), and the timer is reset (step S403).

  After that, it is determined whether the transition source (the staying route) is the main route or the sub route (step S404), and when the transition source is the main route, it is shown in FIGS. When a transition is made (step S405) and the transition source is a secondary path, the transition is made to FIGS. 5B and 5F (step S406).

  In FIG. 5 (f), reception of a packet transmitted with a 1% transmission bandwidth request is monitored on the path side where the stay has occurred (step S501). When the packet is received without exceeding t_limit_N, it is determined whether the transition source is the main route or the sub route (step S503), and when the stayed route is the main route, the transmission bandwidth request BW_req_1. Is set to a second value larger than the first value, for example, 2%, and the timer is reset (t_1 = 0), and the process proceeds to FIG. 5B (step S504). When the route is a slave route, the transmission bandwidth request BW_req_2 is set to 2% and the timer is reset (t_2 = 0), and the process proceeds to FIG. 5C (step S505). In addition, the path | route in which stagnation has not occurred is in FIG.5 (b) or FIG.5 (c) at this time.

  In the path where the stagnation occurs, it waits for reception of a packet transmitted with a bandwidth request of 2%, and if the time (t1 or t2) until the packet is received is t_thresh_1 or t_thresh_2 or less, the stagnation disappears and normal It is determined that the state has returned to the normal state, and thereafter the normal state is returned (step S502). On the other hand, when the time t_thresh_1 or t_thresh_2 has passed without receiving a packet transmitted with a bandwidth request of 2% (step S502), it is determined that the packet is still in a staying state, and the process transitions to FIG. Step S506).

  The times t_thresh_1, t_thresh_2, t_limit_1, and t_limit_2 may be values determined by parameters, or may be values determined only by giving an initial value (for example, 100 ms) and thereafter taking statistics of actual arrival times. .

  As described so far, packets that contain a 1% transmission bandwidth request and packets that contain a 2% transmission bandwidth request are immediately sent to the path where the stagnation occurred, and sent by that packet. The time from when a request is made until it is received can be measured, and the minimum transmission to the staying transmission buffer (if 50 packets per second are transmitted, the transmission bandwidth request is 1 % And 2% are only performed at a rate of 1 per second), so the effect of staying can be minimized and packets with large delays that can be caused by staying are minimized. be able to.

  The present invention is not limited to the above-described embodiment, and many variations or modifications are possible. For example, the communication system 1 includes the wireless IP network 10A and the wireless IP network 10B. However, more wireless IP networks may be used. In the above-described embodiment, the insufficient transmission band is supplemented in both the upstream direction and the downstream direction. However, the transmission band in the upstream direction or the downstream direction may be supplemented. Furthermore, if there is an available wireless communication path that can be used as the transmission path for the transmission path ratio change message, this path can also be used.

  In the above-described embodiment, the case where the packet including the 1% transmission bandwidth request and the packet including the 2% transmission bandwidth request are alternately transmitted has been described. For example, it can be 2% and 3%).

DESCRIPTION OF SYMBOLS 1 Communication system 10A, 10B Wireless IP network 20 Internet 40 IP telephone terminal
100 switching server 101Rx, 103Rx, 105Rx, 301Rx, 303Rx reception interface unit 101Tx, 103Tx, 105Tx, 301Tx, 303Tx transmission interface unit 107, 307 transmission band notification analysis unit 109, 309 reception band measurement unit 111, 311 transmission band calculation unit 113 , 313 Transmission path control means 300 Mobile node (MN)
317 application

Claims (12)

A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control device for controlling communication between the wireless communication device and a communication destination,
Receiving means for receiving bandwidth information of each wireless communication path calculated on the wireless communication device side from the wireless communication device;
Transmission control means for allocating and transmitting packets to each wireless communication path based on the band information received by the receiving means;
A communication control apparatus comprising: a transmission ratio adding means for adding information on a transmission ratio of each wireless communication path to a packet transmitted by the transmission control means. A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control device for controlling communication between the wireless communication device and a communication destination,
Receiving means for receiving a packet to which information of a transmission rate of each wireless communication path transmitted by the wireless communication device is added;
Measuring means for measuring the reception bandwidth of each wireless communication path based on the received packet;
Based on the reception band information measured by the measurement unit after the reception unit receives the packet with the transmission rate information added thereto, information on the transmission rate of the transmission path of the wireless communication device is obtained. A communication control device comprising a notification means for notifying the device. Based on the packet received by the receiving means, further comprising a detecting means for detecting retention of transmission packets of the wireless communication device in each wireless transmission path,
3. The communication control apparatus according to claim 2, wherein when the detection unit detects the stay of the transmission packet, the notification unit notifies the transmission rate to be reduced. A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication device that wirelessly communicates with a communication destination via the communication control device,
Receiving means for receiving the bandwidth information of each wireless communication path calculated on the communication control device side from the communication control device;
Transmission control means for allocating and transmitting packets to each wireless communication path based on the band information received by the receiving means;
A wireless communication apparatus comprising: a transmission ratio adding means for adding information on a transmission ratio of each wireless communication path to a packet transmitted by the transmission control means. A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication device that wirelessly communicates with a communication destination via the communication control device,
Receiving means for receiving a packet to which information on a transmission ratio of each wireless communication path transmitted by the communication control device is added;
Measuring means for measuring the reception bandwidth of each wireless communication path based on the received packet;
Based on the reception band information measured by the measurement unit after the reception unit receives the packet with the transmission rate information added thereto, information on the transmission rate of the transmission path of the communication control device is obtained from the communication control device. A wireless communication apparatus comprising: a notification means for notifying the device. Based on the packet received by the receiving means, further comprising a detecting means for detecting retention of transmission packets of the communication control device in each wireless transmission path,
6. The wireless communication apparatus according to claim 5, wherein when the detection unit detects the stay of the transmission packet, the notification unit notifies the transmission rate to be reduced. A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control method for controlling communication between the wireless communication device and a communication destination,
Band information of each wireless communication path calculated on the wireless communication device side is received from the wireless communication device,
Based on the received bandwidth information, packets are allocated to each wireless communication path and transmitted.
A communication control method, wherein information on a transmission ratio of each wireless communication path is added to the packet to be transmitted. A plurality of different wireless communication paths can be used with the wireless communication device, and the bandwidth that is lacking in one wireless communication path is used for the required bandwidth of the application having real-time characteristics to be used. A communication control method for controlling communication between the wireless communication device and a communication destination,
Receiving a packet to which information of a transmission rate of each wireless communication path transmitted by the wireless communication device is added;
Measure the reception bandwidth of each wireless communication path based on the received packet,
A communication control method, comprising: notifying the wireless communication device of information related to a transmission rate of the transmission path based on information on a reception band measured after receiving a packet to which the transmission rate information is added.   9. The communication control method according to claim 8, wherein when a stay of transmission packets of the wireless communication device in each wireless transmission path is detected based on the received packet, notification is made to reduce the transmission ratio. . A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication method for wirelessly communicating with a communication destination via the communication control device,
The bandwidth information of each wireless communication path calculated on the communication control device side is received from the communication control device,
Based on the received bandwidth information, packets are allocated to each wireless communication path and transmitted.
A wireless communication method, wherein information on a transmission ratio of each wireless communication path is added to the packet to be transmitted. A plurality of different wireless communication paths can be used with the communication control device, and other wireless communication paths can be used for the bandwidth required by one wireless communication path for the requested bandwidth of the application that has real-time characteristics. And a wireless communication method for wirelessly communicating with a communication destination via the communication control device,
Receiving a packet to which information of a transmission ratio of each wireless communication path transmitted by the communication control device is added;
Measure the reception bandwidth of each wireless communication path based on the received packet,
The communication control device is notified of information related to the transmission rate of the transmission path of the communication control device based on information of a reception band measured after receiving the packet with the transmission rate information added thereto. Wireless communication method.   12. The wireless communication method according to claim 11, wherein when a stay of transmission packets of the communication control device in each wireless transmission path is detected based on the received packets, notification is made to reduce the transmission ratio. .

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