JP2010154242A - Method for controlling traffic detour - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling traffic detour for increasing an overall communication traffic amount by optimizing a correspondence relationship between a detour source and a detour destination of an overflow traffic. <P>SOLUTION: When a corresponding detour destination area having empty capacity in relation to a detour source a0 is not present, a common detour destination retrieval part 141 retrieves a detour destination area b0 having an overflow traffic of a detour source area a1 already bypassed and being a corresponding detour destination of the detour source a0 as well, and sets it as a common detour destination area b0. A re-detour destination retrieval part 142 retrieves a corresponding detour destination area b1 having empty capacity in relation to the detour source a1, and sets it as a re-detour destination area. A detour destination changeover part 143 stops or reduces the amount of an overflow traffic bypassed from the detour source area a1 to the common detour destination area b0, and changes over the detour destination to the corresponding detour destination area b1. A detour execution part 144 bypasses the overflow traffic of the detour source area a0 to the common detour destination area b0. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a traffic detour control method for detouring overflow traffic in one communication area to one or more other communication areas in a communication network including a plurality of communication areas.

  When a disaster such as an earthquake or a typhoon occurs, many calls such as safety confirmations and visits are made to the area where the disaster occurred or from the area where the disaster occurred. Since the call that occurs in such a case is several tens of times the normal traffic, congestion may occur in the exchange that accommodates the area and the call may not be connected.

In response to such a technical problem, Non-Patent Document 1 proposes a technique for determining a traffic detour method between communication areas in accordance with the amount of traffic generated for each communication area in normal times.
Next-generation Internet and traffic engineering, Shohei Sato, Makiko Yoshida, IEICE Transactions B Vol.J85-B No.6 pp.875-889: 2002/06/01

  When the generated traffic volume exceeds communication capacity A0, A1 and the free capacity of communication area B0, B1 with sufficient communication capacity overflows to bypass traffic, communication area A0 to B0 can be bypassed, but B1 Cannot be bypassed, can be bypassed from communication area A1 to either B0 or B1, and traffic is already bypassed from communication area A1 to B0. A0 overflow traffic cannot be bypassed.

  At this time, if the detour destination of the communication area A1 can be switched from the communication area B0 to B1, the overflow traffic of the communication area A0 can be detoured to the communication area B0, and the total traffic volume can be increased. . However, in the above prior art, it has not been considered to increase the total communication traffic amount by optimizing the detour destination.

  An object of the present invention is to provide a traffic bypass control method that can solve the above-described problems of the prior art and can increase the total traffic volume by optimizing the correspondence between the bypass source and the bypass destination of overflow traffic. It is to provide.

  In order to achieve the above-described object, the present invention provides a traffic diversion control method for a communication network in which a plurality of communication areas are connected so as to be able to divert traffic to each other. Based on the amount of traffic, the estimation means for estimating the amount of traffic generated in each communication area after the event, and classifying each communication area into a traffic detour source area and a detour destination area based on the estimated traffic volume Classification means, sorting means for selecting a corresponding detour destination area in which traffic can be diverted from the detour destination area for each detour source area, and detour for detouring the traffic of each detour source area to the corresponding detour destination area Control means, and the bypass control means has a corresponding bypass destination area having a free capacity with respect to one bypass source area. In addition, if the detour destination area of the other one detour source area is a common detour destination area that is also a corresponding detour destination of the one detour source area, the other one detour source area to the common detour destination area The detour is stopped or reduced, and the traffic of the one detour source area is detoured to the common detour destination area.

  According to the present invention, the relationship between the detour source and the detour destination is optimized by dynamically switching the detour destination of the overflow traffic generated in the detour source communication area where the generated traffic volume exceeds the communication capacity. The amount of communication traffic can be maximized.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a communication network 1 to which the traffic detour control method of the present invention is applied. N communication areas C1, C2,... Ci,. A detour control server P that controls detouring of traffic between Cis is included.

  FIG. 2 is a block diagram showing the configuration of the main parts of each of the communication areas Ci and the detour control server P. Here, the configuration unnecessary for the description of the present invention is not shown.

  Each communication area Ci includes at least one exchange 2, and each exchange 2 accepts outgoing calls from telephone terminals 4 and incoming calls to telephone terminals 4 accommodated in a radio base station (AP) 3, and makes a call. Establish a road. A relay node 5 is connected between the exchange 2 and the radio base station 3, and each communication area Ci and the detour control server P are connected to each other at the relay node 5. In the present embodiment, each telephone terminal 4 is described as being wireless such as a mobile phone, but may be a wired telephone terminal.

  In the detour control server P, the traffic amount estimation unit 11 estimates the traffic amount generated in each communication area Ci after the event based on the scale of the event occurring in each communication area Ci and the normal traffic amount. In the present embodiment, focusing on the fact that the traffic volume of each communication area Ci varies greatly when a disaster occurs, information representative of the scale of damage in each communication area is collected. That is, the seismic intensity measured in each communication area Ci is collected during an earthquake disaster, and the precipitation, wind speed, or atmospheric pressure measured in each communication area Ci is collected during a typhoon disaster. Then, the estimated traffic volume at the time of the disaster is calculated for each communication area Ci based on the information on the disaster scale and the traffic volume at the normal time.

  The communication area classification unit 12 classifies each communication area Ci into a detour source area (set A) and a detour destination area (set B) based on the estimated traffic volume. The detour destination selection unit 13 selects, for each detour source area, a corresponding detour destination area that can detour traffic from the detour destination area. In this embodiment, a communication area that is not physically connected to the detour source area, a communication area that is not suitable as a detour destination, or a communication area whose distance from the detour source area exceeds the reference value is excluded from the candidates. Other communication areas are selected as corresponding detour destination areas suitable as detour destinations.

The detour control unit 14 detourally distributes the overflow traffic of each detour source area to the free capacity portion of the corresponding detour destination area. Further, as will be described in detail later, the detour control unit 14 has no corresponding detour destination area having a free capacity with respect to one detour source area, and the detour destination of the other detour source area is the one detour. If it is a common bypass destination area that is also a corresponding bypass destination of the original area, the bypass from the other one bypass source area to the common bypass destination area is stopped or reduced, and the traffic of the one bypass source area is reduced to the common bypass destination. Bypass distribution to the free capacity portion secured in the destination area.
[First embodiment]

  FIG. 3 is a functional block diagram showing a configuration of the bypass control unit 14 in the first embodiment of the bypass control server P to which the present invention is applied, and FIG. 4 is a typical example of communication traffic by the bypass control unit 14. It is the figure which showed typically the detour method.

  Here, as shown in FIG. 4 (a), the overflow traffic of the bypass source area a0 is further bypassed in the state where the overflow traffic of the bypass source area a1 is distributed to the empty capacity portion of the bypass destination area b0. Think about the case.

  When there is no corresponding detour destination area with free capacity for one detour source area a0, the common detour destination search unit 141 overflows the other detour source area a1 as shown in FIG. 4 (a). A search is made for a detour destination area b0 in which traffic has already been detoured and is also a corresponding detour destination area of one detour source area a0, and this is set as a common detour destination area b0. The re-detour destination search unit 142 searches for a corresponding detour destination area b1 having free capacity with respect to the other detour source area a1, and sets this as the re-detour destination area b1.

  As shown in FIG. 4B, the detour destination switching unit 143 partially stops detouring from the other detour source area a1 to the common detour destination area b0, and sets the detour destination as the corresponding detour destination area b1. Switch to. After the detour destination is switched, the detour execution unit 144 detours the overflow traffic of one detour source area a0 to the common detour destination area b0 as shown in FIG. 4 (c).

  Next, the operation of the first embodiment of the present invention will be described in more detail along the flowchart. FIG. 5 is a flowchart showing the operation of the detour control server P. Here, the detour control of traffic is executed based on the traffic volume (estimated traffic volume) estimated to occur in each communication area Ci at the time of an earthquake disaster. Is done.

  In step S1, the communication area classification unit 12 compares the estimated traffic volume Qi of each communication area Ci with the communication capacity Qi_ref of each communication area Ci, and the communication area of Qi ≧ Qref is a detour source that requires traffic detouring. The area is determined and classified into set A. On the other hand, the communication area of Qi <Qref is determined as a detour destination area that does not require traffic detouring and is classified as set B.

  In step S2, it is determined whether or not the set A is an empty set. If the set A is an empty set, it is determined that there is no communication area that requires traffic detouring, and the process ends. In step S3, it is determined whether or not the set B is an empty set. If the set B is an empty set, it is determined that there is no communication area serving as a traffic detour destination, and the process ends. If neither of the sets A and B is an empty set, the process proceeds to step S4 and subsequent steps in order to bypass the overflow traffic of each communication area classified as set A to the free capacity portion of each communication area classified as set B.

  In step S4, the current detour source area a0 is arbitrarily selected from the set A. In step S5, the detour destination selection unit 13 selects a corresponding detour destination area candidate that can be the detour destination of the current detour source area a0 from the set B. In step S6, it is determined whether or not there is a corresponding detour destination area of the current detour source area a0. If the corresponding detour destination area exists, the process proceeds to step S7, and the detour control unit 14 detourally distributes the overflow traffic of the current detour source area a0 to the free capacity portion of the corresponding detour destination area.

  In step S8, it is determined whether or not all the overflow traffic in the bypass source area a0 can be bypassed. If the bypass cannot be completed, the process proceeds to step S9. In step S9, when the overflow traffic of the other detour source area a1 of the set A has already been detoured to the corresponding detour destination area b0 that can be detoured from the detour source area a0, the [common detour destination area b0, The common detour destination search unit 141 and the rerouting destination search unit 142 retrieve a set of the rerouting source area a1 and the rerouting destination area b1].

  In step S10, it is determined whether or not the above-described communication area set [b0, a1, b1] exists. If such a group exists, the process proceeds to step S11, and a part of the overflow traffic that has already been detoured from the rerouting source area a1 to the common detouring area b0 is redistributed to the rerouting destination area b1. In step S12, the overflow traffic of the detour source area a0 is detoured to the free capacity generated in the common detour destination area b0 by this re-detour.

  In step S6, it is determined that there is no detour destination candidate, or in step S8, it is determined that all the overflow traffic of the current detour source area a0 has been detoured, or in step S10, the communication area If it is determined that the set [b0, a1, b1] does not exist, the process proceeds to step S13, and the current detour source area a0 is deleted from the set A.

  FIG. 6 is a diagram schematically showing how traffic is detoured according to the flowchart of FIG. 5. As shown in FIG. 6A, the overflow traffic amount in the detour source area a1 is [20]. The overflow traffic volume of the original area a0 is [30]. Also, the free capacity of the detour area b0 is (10), the free capacity of the detour area b1 is (8), the free capacity of the detour area b2 is (15), the free capacity of the detour area b3 is (10), The free space in the detour destination area b4 is (7).

  Furthermore, the broken line arrow in FIG. 4A shows the corresponding detour destination areas of the detour source areas a1 and a0, and the traffic of the detour source area a1 can be detoured to the detour destination areas b0, b2, and b4, but the detour destination area b1 and b3 cannot be bypassed. The traffic in the detour source area a0 can be detoured to the detour destination areas b1, b2, and b3, but cannot be detoured to the detour destination areas b0 and b4.

  In such a configuration, the traffic volume (5), (15) has already been diverted from the detour source area a1 to the detour destination areas b0, b2, respectively. Consider the case of starting a detour.

  Initially, as shown in FIG. 5B, two bypass destination areas b1 and b3 are selected as corresponding bypass destinations of the bypass source area a0, and in step S7, the bypass source area a0 is assigned to each free capacity portion. Overflow traffic volume (8), (10) is bypassed. However, since the overflow traffic volume (12) still remains in the detour source area a0 after this detour, it is determined in step S8 that the detour has not been completed, and the process proceeds to step S9.

  In step S9, a set of [the detour destination area b2, the detour source area a1, the detour destination area b0] is set as the set of the [common detour destination area, re-detour source area, and re-detour destination area]. As shown in c), among the traffic detoured from the rerouting source area a1 to the common detouring destination area b2, the detouring destination with the traffic volume (5) is changed to the rerouting destination area b0. As a result, a free capacity (5) is generated in the common detour destination area b2. Next, as shown in FIG. 4D, the traffic volume (5) is newly detoured from the detour source area a0 to the common detour destination area b2. However, since the overflow traffic volume (7) still remains in the bypass source area a0 after this detour, it is determined that the detour has not been completed in the next step S8, and the process proceeds to step S9.

In step S9, this time, the set of [detour destination area b2, detour source area a1, detour destination area b4] is set as the [common detour destination area, re-detour source area, re-detour destination area]. As shown in FIG. (E), among the traffic detoured from the rerouting source area a1 to the common detouring destination area b2, the detouring destination with the traffic volume (7) is switched to the rerouting destination area b4. As a result, a free capacity (7) is generated in the common detour destination area b2. Next, as shown in FIG. 5F, the traffic volume (7) is newly detoured from the detour source area a0 to the common detour destination area b2, and the detouring of all overflow traffic is completed.
[Second Embodiment]

  FIG. 7 is a functional block diagram showing a configuration of the bypass control unit 14 in the second embodiment of the bypass control server P to which the present invention is applied, and FIG. 8 is a typical example of communication traffic by the bypass control unit 14. It is the figure which showed typically the detour method. Here, as shown in FIG. 8 (a), in the state where the overflow traffic of the bypass source area a1 is bypassed and distributed to the free capacity portions of the bypass destination areas b0 and b1, the overflow traffic of the bypass source area a0 is further increased. Consider the case of detouring.

  In the first embodiment described above, each detour destination communication area has received detour traffic from a plurality of detour source communication areas. However, in this embodiment, each detour destination communication area is a single detour source communication. Assume that detour traffic can only be accepted from the area.

  When there is no corresponding detour destination area having a free capacity for one detour source area a0, the common detour destination search unit 141 has already bypassed the overflow traffic of the other detour source area a1, and A search is made for a detour destination area b0 that is also a corresponding detour destination area of the detour source area a0, and this is set as a common detour destination area b0.

  The detour stop unit 146 stops detouring from the other detour source area a1 to the common detour destination area b0 as shown in FIG. 8B. The detour execution unit 147 detours the overflow traffic of one detour source area a0 to the common detour destination area b0 as shown in FIG. 8C after the detour is stopped. Further, as shown in FIG. 8 (d), the detour execution unit 147 detours the overflow traffic of the other detour source area a1 that has been detoured to another detour destination area b2.

  The traffic amount comparison unit 145 compares the stop traffic amount whose detour is stopped by the detour stop unit 146 and the start traffic amount whose detour is started by the detour execution unit 147. The detour stop unit 146 performs the detour stop on the condition that the start traffic amount exceeds the stop traffic amount. In addition, as shown in FIG. 8 (d), the traffic comparison unit 145 reroutes the stopped detour traffic to another detour destination area b2, so that the common detour destination starts from one detour source area a0. The sum of the traffic volume diverted to the area b0 and the traffic volume diverted from the other one detour source area a1 to the other detour destination area b2 is defined as the start traffic volume.

  Next, the operation of the second exemplary embodiment of the present invention will be described in more detail along the flowchart. FIG. 9 is a flowchart showing the operation of the detour control server P. Here also, the detour control of traffic is executed based on the traffic volume (estimated traffic volume) estimated to occur in each communication area Ci at the time of an earthquake disaster. Is done.

  In step S31, the communication area classification unit 12 compares the estimated traffic amount Qi of each communication area Ci with the communication capacity Qi_ref of each communication area Ci, and the communication area of Qi ≧ Qref is a detour source that requires traffic detouring. The area is determined and classified into set A. On the other hand, the communication area of Qi <Qref is determined as a detour destination area that does not require traffic detouring and is classified as set B.

  In step S32, it is determined whether or not the set A is an empty set. If the set A is an empty set, it is determined that there is no communication area that requires traffic detouring, and the process ends. In step S33, it is determined whether or not the set B is an empty set. If the set B is an empty set, it is determined that there is no communication area serving as a traffic detour destination, and the process ends. If neither of the sets A and B is an empty set, the process proceeds to step S34 and subsequent steps in order to bypass the overflow traffic of each communication area classified as the set A to each communication area classified as the set B.

  In step S34, the current detour source area a0 is selected from the set A. In step S35, the detour destination selection unit 13 selects a corresponding detour destination area candidate from the set B as a detour destination of the current detour source area a0. Selected. In the present embodiment, in step S34, it is preferable that candidates for the corresponding detour destination area selected in the subsequent step S35 are selected in order from the smaller detour source area a0.

  In step S36, it is determined whether or not there is a corresponding detour destination area of the current detour source area a0. If the corresponding detour destination area exists, the process proceeds to step S37, and the detour control unit 14 detourally distributes the overflow traffic of the current detour source area a0 to the free capacity portion of the corresponding detour destination area to which the overflow traffic is not assigned.

  In step S38, it is determined whether or not all the overflow traffic in the bypass source area a0 can be bypassed. If the bypass cannot be completed, the process proceeds to step S39. In step S39, when at least part of the overflow traffic of the other communication area a1 of the set A has already been detoured to the corresponding detour destination area b0 of the detour source area a0, [common detour destination area b0, re-detour The group of the original area a1] is searched by the common detour destination search unit 141.

  In step S40, it is determined whether or not the above-described communication area set [b0, a1] exists. If such a group exists, the process proceeds to step S41, and the actual traffic amount U1 that is bypassed from the bypass source area a1 to the common bypass destination area b0 and the bypass from the bypass source area a0 to the common bypass destination area b0 are started. The start traffic amount U2 is compared by the traffic amount comparison unit 145. If U2> U1, the process proceeds to step S42, and the traffic detour from the detour source area a1 to the common detour destination area b0 is stopped by the detour stop unit 146. In step S43, traffic detouring from the detour source area a0 to the common detour destination area b0 is started.

  If a new detour destination of the overflow traffic that has been detoured in step S42 can be secured, in step S41, the overall traffic volume is increased or decreased in consideration of the traffic detoured to the new detour destination. It is desirable to judge.

  In step S36, it is determined that there is no detour destination candidate, or in step S38, it is determined that all the overflow traffic of the current detour source area a0 has been detoured, or in step S40, the set of communication areas If it is determined that [b0, a1] does not exist or it is determined in step S41 that the traffic volume does not increase (U2 ≦ U1), the process proceeds to step S44, and the current detour source area a0 is deleted from the set A. The

  FIG. 10 is a diagram schematically showing how traffic is detoured according to the flowchart of FIG. 9. As shown in FIG. 10A, the overflow traffic amount in the detour source area a1 is [20]. The overflow traffic volume of the original area a0 is [30]. Also, the free space in the detour area b0 is (15), the free space in the detour area b1 is (5), the free capacity in the detour area b2 is (15), and the free capacity in the detour area b3 is (10). is there.

  Furthermore, the broken line arrows in FIG. 9A indicate the corresponding detour destination areas of the detour source areas a1 and a0, and the traffic of the detour source area a1 can be detoured to the detour destination areas b0 and b2, but the detour destination area b1, b3 cannot be bypassed. The traffic in the detour source area a0 can be detoured to the detour destination areas b1, b2, and b3, but cannot be detoured to the detour destination area b0.

  In such a configuration, the traffic volume (15), (5) has already been diverted from the detour source area a1 to the detour destination areas b0, b2, respectively. Consider the case of starting a detour.

  Initially, as shown in FIG. 5B, two bypass destination areas b1 and b3 are selected, and in step S37, the overflow traffic amount (5), ( 10) is bypassed. However, since the overflow traffic volume (15) still remains in the detour source area a0 after this detour, it is determined in step S38 that the detour has not been completed, and the process proceeds to step S39.

  In step S39, the set of [detour destination area b2 and detour source area a1] is set as the set of [common detour destination area and re-detour source area], and is detoured from re-detour source area a1 to common detour destination area b2. The actual traffic volume U1 and the start traffic volume U2 for starting detouring from the detour source area a0 to the common detour destination area b2 are compared in step S41. If U2> U1, the process proceeds to step S42, and the traffic detour from the re-detour source area a1 to the common detour destination area b2 is stopped as shown in FIG. In step S43, as shown in FIG. 4D, the overflow traffic in the bypass source area a0 is bypassed to the common bypass destination area b2.

  If there is another corresponding detour destination of the detour source area a1, detour traffic that has been detoured in FIG. (C) is represented by the other detour destination area b4 as shown in FIG. Further detour distribution may be made to the free capacity portion.

It is the figure which showed the structure of the communication network to which this invention is applied. FIG. 3 is a block diagram showing configurations of a communication area Ci and a detour control server P. FIG. 3 is a block diagram illustrating a first embodiment of a detour control unit of a detour control server P. It is the figure which showed the detour method of the communication traffic by the detour control part of 1st Embodiment. It is the flowchart which showed the operation | movement of 1st Embodiment of this invention. It is the figure which showed a mode that the traffic was detoured according to the flowchart of FIG. It is the block diagram which showed 2nd Embodiment of the detour control part of the detour control server P. It is the figure which showed the detour method of the communication traffic by the detour control part of 2nd Embodiment. It is the flowchart which showed the operation | movement of 2nd Embodiment of this invention. It is the figure which showed a mode that the traffic was detoured according to the flowchart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Communication network, 2 ... Switching office, 3 ... Wireless base station, 4 ... Telephone terminal, 5 ... Relay node, 11 ... Traffic amount estimation part, 12 ... Communication area classification | category part, 13 ... Detour destination selection part, 14 ... Detour Control unit 141 ... Common detour destination search unit 142 142 Re-detour destination search unit 143 Detour destination switching unit 144 Detour execution unit 145 Traffic amount comparison unit 146 Detour stop unit 147 Detour execution unit

Claims (4)

In a traffic detour control method of a communication network connected so that a plurality of communication areas can detour traffic mutually,
An estimation means for estimating the amount of traffic occurring in each communication area after the event based on the scale of the event occurring in each communication area and the amount of traffic in normal times;
Classification means for classifying each communication area into a traffic detour source area and a detour destination area based on the estimated traffic volume,
For each detour source area, a screening means for selecting a corresponding detour destination area that can detour traffic from the detour destination area;
A detour control means for detouring the traffic of each detour source area to the corresponding detour destination area,
The detour control means does not have a corresponding detour destination area having a free capacity with respect to one detour source area, and the detour destination area of the other detour source area is also a corresponding detour destination of the one detour source area When it is a common detour destination area, the detour from the other one detour source area to the common detour destination area is stopped or reduced, and the traffic of the one detour source area is detoured to the common detour destination area Traffic detour control method. The detour control means is
When there is no corresponding detour destination area with free capacity for one detour source area, the traffic of the other detour source area has already been detoured and is also the corresponding detour destination area of the one detour source area A common detour search means for searching a common detour area,
Re-detour destination search means for searching for another corresponding detour destination area having a free capacity with respect to the other detour source area;
A detour destination switching means for switching a detour destination of a part of the traffic detoured from the other one detour source area to the common detour destination area, to the other corresponding detour destination area;
The traffic detour control method according to claim 1, further comprising detour execution means for detouring the traffic of the one detour source area to the common detour destination area after the detour destination is switched. The detour control means is
When there is no corresponding detour destination area with free capacity for one detour source area, the traffic of the other detour source area has already been detoured and is also the corresponding detour destination area of the one detour source area A common detour search means for searching a common detour area,
Detour stopping means for stopping detouring from the other one detour source area to the common detour destination area;
Detour execution means for detouring the traffic of the one detour source area to the common detour destination area after stopping the detour;
Comparing means for comparing the amount of stop traffic stopped by the bypass stop means and the amount of start traffic started by the bypass execution means,
The traffic detour control method according to claim 1, wherein the detour stop unit stops detouring when the start traffic amount exceeds the stop traffic amount. The detour execution means further includes means for detouring traffic of the other one detour source area to another corresponding detour destination;
The comparison means includes a traffic amount that starts to be bypassed from the one bypass source area to a common bypass destination area, and a traffic amount that starts to bypass the other one bypass source area to another corresponding bypass destination. The traffic detour control system according to claim 3, wherein the sum of the values is used as a start traffic amount.

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