JP6405532B2 - Route control device, route control method and program - Google Patents

Description

  The present invention relates to a path control device, a path control method, and a program. In particular, the present invention relates to a path control apparatus, a path control method, and a program for controlling a transfer apparatus that forms a backhaul line.

  A mobile network used in a smartphone or the like includes a base station and a mobile backhaul line that connects the base station to a core network. When accommodating the traffic of the base station in the core network, it is necessary to set a path (packet transfer route) on the mobile backhaul. The route setting (path setting) in this mobile backhaul has a great effect on the accommodation efficiency and fault tolerance of data traffic.

  In particular, in the mobile backhaul, a radio link is often used, and the influence of route setting is great. That is, since the link bandwidth of a wireless link varies depending on the weather or the like, effective route setting on the mobile backhaul is important.

  In Patent Document 1, a network including a communication device that communicates by a wireless link using adaptive modulation, a future modulation mode of the wireless link is predicted, and a communication path is set in the network based on the predicted mode that is the predicted modulation mode. A configuration having a path control device to be set is disclosed. Patent Document 2 discloses a method of sharing a backhaul line among a plurality of communication companies. Patent Document 3 discloses a method for changing a transfer path in accordance with a load on a gateway device.

International Publication No. 2010/016477 JP 2007-129401 A JP 2008-078935 A

  Each disclosure of the above prior art document is incorporated herein by reference. The following analysis was made by the present inventors.

  As described above, a radio link is often used in a mobile network, and it is desired to improve the fault tolerance of the network. As one method for improving the fault tolerance of a mobile network, it is conceivable to employ a redundant configuration in which a plurality of base stations cover the same area. However, even if redundancy is performed at the base station level, if the transfer path on the mobile backhaul connected to these base stations is common, a failure that occurred in the mobile backhaul (failure caused by the same cause) ) Affects each base station, and redundant base stations do not make sense.

  On the other hand, a redundant configuration on the mobile backhaul side is also conceivable. That is, it is possible to take measures to make mobile backhaul lines redundant (redundant routes) for transfer routes formed corresponding to each base station. However, due to topology restrictions in the network, it is difficult to make mobile backhaul lines redundant for transfer paths corresponding to all base stations. Furthermore, when a link failure or a transmission rate decrease occurs, it is necessary to change from a transfer route via the failed link to a detour route. However, there are cases where there are a plurality of base stations that are affected by a link failure or the like, and there is not enough free bandwidth in the mobile backhaul link. In such a case, there is a problem that the coverage area (coverage area) of the mobile network varies greatly depending on which transfer path corresponding to which base station is preferentially changed to a detour path.

  An object of the present invention is to provide a path control device, a path control method, and a program that contribute to reducing the influence of a failure on the mobile backhaul side on the performance of the entire mobile network.

According to a first aspect of the present invention, the multiplicity calculation section which exits calculate the area in which each coverage area a plurality of base stations are duplicated as duplicate of the packet to form a trunk line between the base station and the network A route calculation unit that calculates a transfer route of the device, and a route setting unit that sets a processing rule according to the transfer route to a transfer device included in the transfer route among a plurality of transfer devices that form the relay line; , And the route calculation unit calculates a transfer route using the redundancy.

According to a second aspect of the present invention, the steps of leaving calculate the area of a plurality of base stations each coverage area overlap as the degree of overlapping, the packets forming the trunk line between the base station and the network transfer path And setting a processing rule corresponding to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line, and In the calculating step, a path control method is provided in which the forwarding path is calculated using the redundancy.

According to a third aspect of the present invention, a process of leaving calculate the area of a plurality of base stations each coverage area overlap as the degree of overlapping, the packets forming the trunk line between the base station and the network transfer path And a process for setting a processing rule corresponding to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line. In addition, a program for calculating the transfer path using the redundancy is provided for the process of calculating the transfer path.
This program can be recorded on a computer-readable storage medium. The storage medium may be non-transient such as a semiconductor memory, a hard disk, a magnetic recording medium, an optical recording medium, or the like. The present invention can also be embodied as a computer program product.
According to the fourth aspect of the present invention, a redundancy calculation unit that calculates the number of connected users in the overlapping area of each of a plurality of base stations as a redundancy, and a packet formed on a relay line between the base station and the network A route calculation unit that calculates a transfer route of the device, and a route setting unit that sets a processing rule according to the transfer route to a transfer device included in the transfer route among a plurality of transfer devices that form the relay line; , And the route calculation unit calculates a transfer route using the redundancy.

  According to each aspect of the present invention, a path control device, a path control method, and a program that contribute to reducing the influence of a failure on the mobile backhaul side on the performance of the entire mobile network are provided.

It is a figure for demonstrating the outline | summary of one Embodiment. It is a figure which shows an example of a structure of the communication network which concerns on 1st Embodiment. It is a flowchart which shows an example of operation | movement of a backhaul management apparatus. It is a figure which shows an example of an internal structure of the backhaul management apparatus which concerns on 1st Embodiment. It is a flowchart which shows an example of operation | movement of a backhaul management apparatus. It is a figure for demonstrating the operation | movement which concerns on the path | route setting of a backhaul management apparatus. It is a figure for demonstrating the operation | movement which concerns on the path | route setting of a backhaul management apparatus. It is a figure for demonstrating the operation | movement which concerns on the path | route setting of a backhaul management apparatus. It is a figure for demonstrating the operation | movement which concerns on the path | route setting of a backhaul management apparatus. It is a flowchart which shows an example of the operation | movement which concerns on the detour route setting of a backhaul management apparatus. It is a figure for demonstrating the operation | movement which concerns on the detour route setting of a backhaul management apparatus. (A) an example of the average number of connected users in the base station in the second embodiment, (b) an example of the overlapping area of the cover area of the base station, and (c) an example of the degree of overlap between the base stations, FIG. It is a figure for demonstrating operation | movement of the backhaul management apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating operation | movement of the backhaul management apparatus which concerns on 2nd Embodiment. It is a figure which shows an example of a system configuration in the case of controlling a base station management apparatus and a backhaul management apparatus by an integrated controller.

  First, an outline of one embodiment will be described. Note that the reference numerals of the drawings attached to the outline are attached to the respective elements for convenience as an example for facilitating understanding, and the description of the outline is not intended to be any limitation.

  Control of the base station constituting the mobile network and the backhaul line is performed by each management system. Therefore, it is difficult to improve the fault tolerance of traffic with redundancy at the base station level or backhaul line level. In particular, even if the base station level is overlapped by overlapping the coverage area of the base station, if the backhaul route is common, redundancy at the base station level is meaningless due to the same link failure, etc. May be. That is, under such circumstances, a path control device that reduces the influence of a failure on the mobile backhaul side on the performance of the entire mobile network is desired.

  Therefore, the path control device 100 shown in FIG. 1 is provided as an example. The route control device 100 includes a redundancy calculation unit 101, a route calculation unit 102, and a route setting unit 103. The overlapping degree calculating unit 101 calculates the overlapping degree indicating the overlapping degree of characteristics between base stations. The route calculation unit 102 calculates the transfer route of the packet formed on the relay line between the base station and the network. The path setting unit 103 sets a processing rule corresponding to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses that form a relay line. Furthermore, the route calculation unit 102 calculates a transfer route using the degree of duplication.

  The overlapping degree calculating unit 101 calculates the overlapping degree of the characteristics that the plurality of base stations forming the mobile network have in common as the overlapping degree between the base stations. For example, the overlapping degree calculating unit 101 calculates an overlapping area between two base stations as the overlapping degree. For example, the route calculation unit 102 selects a base station pair having a high degree of redundancy, and calculates a transfer route (packet transfer route) corresponding to each of the two base stations forming the base station pair. At that time, for example, the route calculation unit 102 calculates a transfer route so that the two transfer routes do not share a link with each other. As a result, the transfer paths set in the relay lines of the two base stations (base station pairs) having high redundancy do not share a link with each other. Therefore, even if a link failure occurs, the two transfer paths are not affected by the failure at the same time. Therefore, even when a link failure or the like occurs and the transfer path corresponding to one of the two base stations is not connected, the other transfer path remains alive. At that time, because the degree of duplication between the two base stations is high, the user connected to the base station on the side where the transfer path is disconnected is reconnected to the base station on the side where the transfer path is alive. The overall performance of the mobile network can be maintained. In this way, the path control device 100 realizes redundancy in which the base station and the backhaul cooperate by setting the path to the backhaul line using information such as the overlap of the cover areas between the base stations.

  Hereinafter, specific embodiments will be described in more detail with reference to the drawings. In addition, in each embodiment, the same code | symbol is attached | subjected to the same component and the description is abbreviate | omitted.

[First Embodiment]
The first embodiment will be described in more detail with reference to the drawings.

  FIG. 2 is a diagram illustrating an example of a configuration of a communication network according to the first embodiment. Referring to FIG. 2, the communication network includes a plurality of base stations 10-1 to 10-4, a plurality of transfer devices 20-1 to 20-20-6, a base station management device 30, and a backhaul management device 40. And comprising. Note that the configuration of the communication network illustrated in FIG. 2 is an example, and is not intended to limit the number of base stations and transfer devices.

  If there is no particular reason for distinguishing the base stations 10-1 to 10-4, they are simply expressed as “base station 10”. Similarly, when there is no particular reason for distinguishing the transfer devices 20-1 to 20-6, the transfer device 20 is described as “transfer device 20”.

  The base station 10 provides connection by a wireless access method to a mobile terminal (not shown) or the like that is to be connected to the communication system. The base station 10 is connected to any one of the plurality of transfer devices 20 by wire. The communication method of the base station 10 is not particularly limited, and the communication method of the base station 10 may be a Wi-Fi (Wireless Fidelity) method such as IEEE802.11a / b / n / g, an LTE (Long Term Evolution) method, or the like. A combination of these may also be used.

  The transfer device 20 is a device that transfers packets transmitted and received between the base station 10 and the core network. The transfer device 20 forms a backhaul line (relay line) between the base station 10 and the core network. The transfer devices 20 are connected by a wireless link. In the example of FIG. 2, the transfer device 20-6 is connected to the core network. In the following drawings including FIG. 2, when a line between nodes is written with a solid line, it is assumed that the node is connected with a wire, and when it is written with a broken line, the node is wirelessly connected. It shall be connected with.

  The base station management device 30 is a device that controls and manages the base station 10. The base station management device 30 is connected to each base station through a dedicated control line (not shown).

  The backhaul management device 40 is a device that controls and manages the transfer device 20. The backhaul management device 40 is connected to each transfer device 20 through a dedicated control line (not shown). Further, the base station management device 30 and the backhaul management device 40 are connected by a dedicated line (not shown) or the like, and are configured to be able to exchange data. The backhaul management device 40 includes the function of the route control device 100 described above.

  The backhaul management device 40 cooperates with the base station management device 30 to control and manage the transfer device 20, thereby realizing a connection between the base station and the core network.

  The operation of the backhaul management device 40 is roughly divided into an operation related to route setting (packet transfer route setting) and an operation related to detour route setting after route setting.

  FIG. 3A is a flowchart illustrating an example of an operation related to route setting of the backhaul management device 40. First, the backhaul management device 40 calculates the degree of overlap related to the cover area for each base station (step S101). Thereafter, the backhaul management device 40 calculates a transfer path from each base station to the core network based on the calculated degree of duplication, and performs path setting (path setting) (step S102).

  FIG. 3B is a flowchart illustrating an example of the operation of the backhaul management device 40 relating to detour route setting. First, when a link failure or the like occurs, the backhaul management device 40 extracts a transfer path (path) that is a detour target (step S201). Thereafter, the backhaul management device 40 performs route change (detour route setting) in consideration of the degree of duplication between base stations (step S202).

  FIG. 4 is a diagram illustrating an example of an internal configuration of the backhaul management device 40. Referring to FIG. 4A, the backhaul management device 40 includes a communication unit 41, a network control unit 42, a traffic information management unit 43, a topology information management unit 44, and a base station information management unit 45. Consists of including.

  The communication unit 41 is a communication interface between the transfer device 20 and the base station management device 30.

  With reference to FIG. 4B, the network control unit 42 includes a redundancy calculation unit 51, a route calculation unit 52, and a route setting unit 53.

  The redundancy calculation unit 51 is a means for calculating the redundancy between base stations. In the first embodiment, the overlap degree calculation unit 51 employs the cover area of each of the two base stations as an index indicating the characteristics between the base stations. The overlapping degree calculating unit 51 calculates a ratio of areas overlapping each other in the cover area of each base station 10 as the overlapping degree between the base stations 10.

  The route calculation unit 52 is a means for calculating a transfer route formed on a backhaul line (relay line) between the base station 10 and the core network. At that time, the route calculation unit 52 calculates the transfer route using the degree of overlap between the base stations. The calculation of the transfer path using the redundancy between the base stations will be described later.

  The path setting unit 53 is a means for setting a processing rule corresponding to the calculated transfer path to the transfer apparatuses 20 included in the transfer path among the transfer apparatuses 20. That is, the path setting unit 53 sets a processing rule for realizing the calculated transfer path in the transfer apparatus 20. More specifically, the path setting unit 53 sets, for each transfer device, a processing rule that determines from which port (channel) of the own device the packet received from each port (channel) is to be transmitted. The processing rule is defined as table information including, for example, a pair of reception port and transmission port.

  The traffic information management unit 43 is means for managing the traffic information of the backhaul line.

  The topology information management unit 44 is means for managing the topology information of the backhaul line. More specifically, the topology information management unit 44 manages the network configuration of the transfer device 20, link information of radio links that configure the backhaul line, and connection information regarding each base station 10.

  The base station information management unit 45 is means for managing base station information. More specifically, the base station information management unit 45 includes information on the position of the base station 10 (hereinafter referred to as base station position information) and information on the coverage area range of each base station 10 (hereinafter referred to as cover area information). Information).

  The backhaul management device 40 not only performs path control of the transfer device 20 constituting the backhaul line, but also acquires base station information including the cover area information of each base station 10 from the base station management device 30, Managed by the base station information management unit 45. Further, the network control unit 42 uses base station information stored in the base station information management unit 45 in addition to topology information and traffic information when performing path setting for each transfer device 20.

  Next, the operation of the backhaul management device 40 will be described.

  First, an operation for calculating a transfer path and setting a processing rule in the transfer apparatus 20 will be described with reference to FIG.

  In step S <b> 301, the overlap degree calculation unit 51 calculates the overlap degree of the cover area for each base station 10. Specifically, the duplication degree calculation unit 51 acquires the cover area information of each base station 10 from the base station management device 30. Based on the cover area information acquired from the base station management device 30, the duplication degree calculation unit 51 calculates the duplication degree based on the area of the cover area included in each base station 10 and stores it in the base station information management unit 45.

  In step S302, the route calculation unit 52 selects a pair of base stations having the highest redundancy based on the calculated redundancy.

  In step S303, the path calculation unit 52 determines whether or not the transfer path to the core network is formed on the backhaul line for each base station that forms the selected base station pair.

  If the transfer route corresponding to each base station is not formed (step S303, No branch), the route calculator 52 calculates the transfer route from the base station to the core network (step S304). Thereafter, the path setting unit 53 sets a processing rule for realizing the calculated transfer path in each transfer apparatus 20.

  In step S305, the route calculation unit 52 excludes the base station pair for which the transfer route is set from the transfer route setting candidates.

  If both transfer paths corresponding to the base stations 10 forming the selected base station pair have already been set (step S303, Yes branch), the path calculation unit 52 excludes the base station pair (step S305). .

  In step S306, the route calculation unit 52 determines whether route setting has been completed for all base stations. If the route setting for all base stations has not been completed (step S306, No branch), the route calculation unit 52 returns to step S302 and continues the processing. If the route setting for all the base stations has been completed (step S306, Yes branch), the route calculation unit 52 ends the route setting operation for the transfer device 20.

  Next, the operation related to the above route setting will be described more specifically with reference to FIGS.

  As shown in FIG. 6, base stations that are targets of route setting to the core network are base stations 10-1 to 10-4. In addition, transfer devices constituting the backhaul line are transfer devices 20-1 to 20-6. In the network configuration shown in FIG. 6, a description will be given of route setting from each base station 10 to the core network connected to the transfer device 20-6.

  In FIG. 7, the cover areas of the base stations 10-1 to 10-4 are shown by dotted lines. Referring to FIG. 7, the cover area 201 is a cover area of the base station 10-1. Similarly, the cover area 202 is the cover area of the base station 10-2, the cover area 203 is the cover area of the base station 10-3, and the cover area 204 is the cover area of the base station 10-4. Referring to FIG. 7, it is understood that the cover areas of each of the base stations 10-1 to 10-4 have a partially overlapping relationship.

  The duplication degree calculation unit 51 acquires base station information (base station position information and cover area information) regarding the base stations 10-1 to 10-4 from the base station management device 30. The duplication degree calculation unit 51 calculates the duplication degree between the base stations 10-1 to 10-4 based on the acquired base station information.

  Here, it is assumed that the degree of overlap between the base stations included in the base stations 10-1 to 10-4 is calculated as shown in FIG. In the following description, when calculating the degree of duplication between base stations, a base station serving as a reference is referred to as a reference base station, and other base stations are referred to as target base stations. For example, referring to FIG. 7, if the base station 10-1 is a reference base station and the base station 10-2 is a target base station, a quarter (25%) of the cover area 201 of the base station 10-1 is included. It can be seen that this area overlaps the cover area 202 of the base station 10-2 (see the first line in FIG. 8A).

  When the degree of overlap shown in FIG. 8A is graphed, it is as shown in FIG. In FIG. 8B, the output source of the arrow indicates the reference base station, and the output destination of the arrow indicates the target base station.

  The route calculation unit 52 selects the base station pair having the highest redundancy from the calculated redundancy. In the example of FIG. 8A, the route calculation unit 52 first selects the base station 10-2 and the base station 10-3. This is because the degree of overlap between these base stations is as high as 70%.

  Next, the route calculation unit 52 calculates the transfer route to be formed on the backhaul line for each of the two selected base stations 10-2 and 10-3. Specifically, the route calculation unit 52 performs route calculation so that the two transfer routes do not share a link. That is, the route calculation unit 52 performs route calculation so that the transfer route from the base station 10-2 to the core network and the transfer route from the base station 10-3 to the core network have a Disjoint relationship. As a method for calculating the Disjoint path, a method disclosed in “JW Survalle,“ Disjoint Paths in a Network ”, Networks, Vol4, pp125-145” can be used. However, if a complete Disjoint path cannot be set due to topology restrictions, some transfer paths may overlap. In such a case, the route calculation unit 52 performs route calculation using the Dijkstra method.

  As a result of the route calculation by the route calculation unit 52, the transfer route from the base station 10-2 to the core network is a route 302 via the transfer devices 20-2, 20-5, and 20-6 (see FIG. 9). Similarly, the transfer path from the base station 10-3 to the core network is a path 303 that passes through the transfer apparatuses 20-3, 20-4, and 20-6. Thus, the transfer paths from the two base stations 10-2 and 10-3 to the core network are calculated so as not to have a common link.

  Next, the route calculation unit 52 selects a base station pair having a high degree of overlap among base stations for which a transfer route has not yet been formed. In the example of FIGS. 7 and 8, the route calculation unit 52 has not yet formed the transfer route of the base station 10-1, and the base stations 10-1 and 10-2 have high redundancy (30%). Select a pair. Also in this case, the transfer path from the base station 10-1 to the core network is calculated so as to have a Disjoint relationship with the transfer path of the base station 10-2. As a result of the route calculation, a route from the base station 10-1 to the core network is a route 301 that passes through the transfer apparatuses 20-1, 20-4, and 20-6 (see FIG. 9).

  Next, the path calculation unit 52 selects a base station pair that includes a base station that has not yet been set with a transfer path and that has the highest degree of duplication. The route calculation unit 52 selects a pair of base stations 10-3 and 10-4 and calculates a transfer route corresponding to the base station 10-4. As a result of the route calculation, the transfer route from the base station 10-4 to the core network is a route 304 that passes through the transfer devices 20-3, 20-2, 20-5, and 20-6 (see FIG. 9).

  As described above, the route calculation unit 52 performs route calculation so that the transfer route to the core network between base stations having overlapping cover areas has a Disjoint relationship.

  Next, the operation | movement which concerns on the detour route setting of the backhaul management apparatus 40 is demonstrated, referring FIG. For example, when the transmission rate decreases due to the influence of rainfall or the like, or when a link failure occurs, an operation related to detour route setting is performed.

  In step S401, when the link calculation unit 52 detects a link failure or the like, the route calculation unit 52 extracts a transfer route (a transfer route affected by the failure) using the link in which the failure has occurred.

  In step S402, the path calculation unit 52 investigates the degree of overlap between the base station that is the connection destination of the extracted transfer path and another base station. At that time, the route calculation unit 52 excludes the base station whose own transfer route is affected by a link failure or the like from the duplication degree investigation.

  In step S403, the route calculation unit 52 changes the setting to the detour route with priority given to the transfer route having a low degree of overlap with the other base station calculated in step S402 among the transfer routes affected by the link failure or the like. I do. However, the route calculation unit 52 may not change to the detour route when the other base station can maintain its own cover area.

  Next, with reference to FIG. 11, the operation related to the detour route setting will be specifically described. Here, it is assumed that a link failure has occurred in the link between the transfer device 20-2 and the transfer device 20-5 after the path setting shown in FIG. 9 has been performed (see FIG. 11A).

  Since the path 302 corresponding to the base station 10-2 and the path 304 corresponding to the base station 10-4 use the link, it is necessary to change the path (detour path setting) regarding these base stations. At this time, the free bandwidth of each link is limited, and only one transfer path out of the two transfer paths can be set as a bypass path. That is, it is assumed that any one of the route 302 of the base station 10-2 and the route 304 of the base station 10-4 has a restriction that a detour route can be set.

  Referring to FIG. 8, the degree of overlap between the base station 10-2 and another base station is 30% with the base station 10-1, and 70% with the base station 10-3. On the other hand, the degree of overlap between the base station 10-4 and another base station is 10% with the base station 10-3.

  In this case, the coverage area of the base station 10-2 can be complemented by the base station 10-1 and the base station 10-3, and the transfer path of both base stations is normal. The transfer route has little effect even if the current state is maintained (even if it is disconnected). On the other hand, the cover area of the base station 10-4 hardly overlaps with the cover areas of other base stations, and there are few base stations that can complement the base station 10-4.

  Therefore, the route calculation unit 52 changes the route by giving priority to the route 304 of the base station 10-4. Specifically, the route calculation unit 52 resets the route 304a including the transfer devices 20-3, 20-5, and 20-6 as the transfer route of the base station 10-4 (see FIG. 11B). .

  Thereafter, the backhaul management device 40 notifies the base station 10-2 of the route change information via the base station management device 30. The base station management device 30 executes control for reconnecting a terminal connected to the base station 10-2 to the base station 10-1 or the base station 10-3. As a result, even if a link failure or the like occurs, the influence of the cover area is minimized.

  As described above, the backhaul management device 40 according to the first embodiment uses the degree of overlap between base stations when calculating a transfer path corresponding to each base station 10. The backhaul management device 40 calculates a transfer path corresponding to the base station 10 so that the transfer paths between the base stations having a strong overlapping relationship have a Disjoint relationship (a relationship not sharing a link). As a result, transfer paths between base stations that are in a strong overlapping relationship are less likely to be affected by the same failure. That is, the influence of the same link failure, for example, reducing the coverage area of the base station is suppressed, and the performance of the entire mobile network is maintained.

  Furthermore, the backhaul management device 40 according to the first embodiment sets a detour route for the base station 10 when a link failure occurs between the transfer devices 20 or when the transmission rate decreases. At this time, the backhaul management device 40 gives priority to the transfer path of the base station 10 that is affected by the link failure and has a low degree of redundancy with other base stations in an environment where the network resources are limited. To select and set a detour route. As a result, the degradation of the network quality of the entire mobile network is suppressed to the minimum.

[Second Embodiment]
Next, a second embodiment will be described in detail with reference to the drawings.

  In the first embodiment, the case where the overlapping area of the cover area in each base station is used as an index for measuring the degree of overlap between base stations has been described. 2nd Embodiment demonstrates the case where the parameter | index which considered the average of the user connected to a base station is used as a parameter | index which measures a duplication degree. In addition, the backhaul management device 40 according to the second embodiment performs route calculation by reflecting the degree of duplication in the link cost in route setting.

  For example, it is assumed that the average number of connected users per unit area of each of the base stations 10-1 to 10-4 illustrated in FIG. 6 is A1, A2, A3, and A4. Also, the overlapping area of the cover areas of the base stations 10-1 and 10-2 is B1, the overlapping area of the cover areas of the base stations 10-2 and 10-3 is B2, and the covering areas of the base stations 10-1 and 10-3 Is the overlap area B3, and the overlap area of the cover areas of the base stations 10-3 and 10-4 is B4.

  In this case, the duplication degree calculation unit 51 calculates the duplication degree between the base stations by using these pieces of information (average number of connected users, duplication area). For example, assume that the average number of connected users is as shown in FIG. 12A, and the overlapping area of the base station cover area is as shown in FIG. In this case, the degree of overlap between base stations is calculated as shown in FIG. For example, the degree of overlap between the base station 10-1 and the base station 10-2 is calculated as A1 × B1 = 600 people.

  The operation of the backhaul management device 40 according to the second embodiment will be described using FIG. 13 and FIG. 14 under the degree of overlap between base stations as shown in FIG. In FIG. 13 and FIG. 14, the numbers given in the vicinity of each link indicate the link cost of the link.

  The route calculation unit 52 performs route calculation in the order of the base station pairs having the highest calculated redundancy value. In other words, the route calculation unit 52 performs route calculation in the order of base station pairs having a large number of overlapping users.

  In the example of FIG. 12 (c), the path calculation unit in the order of the pair of base stations 10-1 and 10-2, the pair of base stations 10-1 and 10-3, and the pair of base stations 10-4 and 10-3. 52 performs route calculation. For example, the route calculation unit 52 sets a route 401 that passes through the transfer devices 20-1, 20-4, and 20-6 as the transfer route of the base station 10-1 (see FIG. 14B).

  Next, the route calculation unit 52 calculates a transfer route corresponding to the base station 10-2. At that time, the route calculation unit 52 sets the base station that is the target of route calculation as the reference base station and the base station that has completed the route calculation as the target base station, and determines the degree of overlap between the two base stations. The link cost is added to the transfer path of the base station. In the above example, when calculating the transfer route of the base station 10-2, the route calculation unit 52 adds the redundancy 150 to the link cost of each link forming the transfer route of the base station 10-1.

  FIG. 13A is a diagram in which the link cost for calculating the transfer path of the base station 10-2 is reflected on the link forming the transfer path of the base station 10-1. The route calculation unit 52 calculates the minimum cost route of the base station 10-2 using the link cost to which the redundancy is added. As a result, the route calculation unit 52 calculates the route 402 that passes through the transfer devices 20-2, 20-5, and 20-6 as the transfer route of the base station 10-2 (see FIG. 14B).

  Next, the route calculation unit 52 calculates a transfer route corresponding to the base station 10-3. At this time, the path calculation unit 52 reflects the degree of overlap between the base station 10-3 and the base stations 10-1 and 10-2 for which transfer paths have already been set, in the link cost. Specifically, the route calculation unit 52 uses the link cost of the link forming the transfer route of the base station 10-1 to determine the degree of duplication with the base station 10-3 as the reference base station and the base station 10-1 as the target base station. Of 100 is added. Similarly, the path calculation unit 52 determines the link cost of the link that forms the transfer path of the base station 10-2 to a link degree of 150 with the base station 10-3 as the reference base station and the base station 10-2 as the target base station. Are added (see FIG. 13B). The route calculation unit 52 calculates a transfer route corresponding to a new base station (the base station 10-3 in the above example) after initializing the already set link cost.

  The route calculation unit 52 searches for the minimum cost route on the link cost to which the redundancy is added, and determines the transfer route of the base station 10-3. The route calculation unit 52 calculates a route 403 that passes through the transfer devices 20-3, 20-5, 20-4, and 20-6 as the transfer route of the base station 10-3 (see FIG. 14B).

  Similarly, in the route calculation (route search) corresponding to the base station 10-4, the link cost in consideration of the overlapping degree between the base station 10-4 and the base stations 10-1 to 10-3 for which the route has already been set. Reflected. In this case, since the base station 10-4 is in an overlapping relationship only with the base station 10-3, the base station 10-4 is connected to the base station 10-3 as a reference base station, a base, and the link forming the transfer path of the base station 10-3. 300, which is the degree of duplication with the station 10-3 as the target base station, is added (see FIG. 14A).

  The route calculation unit 52 searches for the minimum cost route on the link cost to which the redundancy is added, and determines the transfer route of the base station 10-4. The route calculation unit 52 calculates the route 404 that passes through the transfer devices 20-3, 20-2, 20-5, and 20-6 as the transfer route of the base station 10-4, and sets the route 404 in each transfer device 20.

  As described above, the backhaul management device 40 according to the second embodiment sets the high redundancy as the link cost for the link forming the transfer path of the base station having a high redundancy. As a result, route setting to a highly redundant link is avoided as much as possible, and route calculation is performed so that the links of the highly redundant base stations are not the same. Therefore, as in the first embodiment, the influence of the coverage area of the base station being reduced due to the influence of the same link failure is suppressed, and the performance of the entire mobile network is maintained.

  The configuration and operation of the backhaul management device 40 described in the first and second embodiments are examples, and various modifications can be made. For example, as shown in FIG. 15, a function corresponding to the network control unit 42 of the backhaul management device 40 is realized by an integrated controller 60 that controls the base station management device 30 and the backhaul management device 40 in an integrated manner. Also good.

  Further, in the first embodiment, when selecting a base station with a high degree of overlap, it is not simply to select a base station with a high overlap ratio of the cover areas, but an average, maximum value, or minimum value of the degree of overlap between base stations. May be used. In addition, in the calculation of the degree of overlap of the coverage area of the base station, the base station is not required to calculate the number of users existing in the overlapping area, the number of users that can be accommodated in the base station, the total communication speed, etc. You may use as a parameter | index showing the overlapping relationship of.

  The processing performed by each unit such as the network control unit 42 of the backhaul management device 40 can be realized by a computer program that causes a computer mounted on the backhaul management device 40 to execute the above-described processing using the hardware. That is, it is only necessary to have a means for executing the function performed by the network control unit 42 and the like with some hardware and / or software.

  Furthermore, by installing the above-described computer program in the storage unit of the computer, the computer can function as a path control device. Furthermore, the route control method can be executed by a computer by causing the computer to execute the above-described computer program. The program can be downloaded via a network or updated using a storage medium storing the program.

  A part or all of the above embodiments can be described as in the following supplementary notes, but is not limited thereto.

[Appendix 1]
A degree-of-duplication calculator that calculates the degree of overlap indicating the degree of overlap of characteristics between base stations;
A route calculation unit for calculating a transfer route of a packet formed on a relay line between the base station and the network;
A path setting unit that sets a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
With
The route calculation unit is a route control device that calculates the transfer route using the redundancy.
[Appendix 2]
The path control device according to supplementary note 1, wherein the path calculation unit calculates in order from the transfer path corresponding to the base stations forming the base station pair having a high redundancy.
[Appendix 3]
The route calculation unit
The path control device according to appendix 1 or 2, wherein a transfer path for setting a detour path is selected from the transfer paths affected by a link failure or a transmission rate decrease by using the redundancy.
[Appendix 4]
The path calculator, when selecting a transfer path for setting the detour path, if there are a plurality of base stations that are affected by the link failure or transmission rate reduction, The route control device according to supplementary note 3, wherein the detour route corresponding to the base station having a low degree of overlap with the base station is preferentially calculated.
[Appendix 5]
The overlapping degree calculating unit calculates the overlapping degree using any one of the overlapping area of the cover area and the number of connected users in the overlapping area of the cover area of each base station. The described route control device.
[Appendix 6]
When calculating the transfer path corresponding to the base station forming the base station pair for which the degree of redundancy is calculated, the path calculation unit does not link the transfer paths corresponding to the base stations forming the base station pair with each other. The path control device according to any one of appendices 1 to 5, which calculates a transfer path so as to be shared.
[Appendix 7]
The path calculation unit reflects the degree of duplication between the base station in which the transfer path is formed and the base station for which the transfer path is calculated, in the link cost of the relay line, and also reflects the degree of duplication. The path control device according to any one of appendices 1 to 5, wherein a transfer path corresponding to a base station for which the transfer path is to be calculated is calculated using the determined link cost.
[Appendix 8]
The route calculation unit
Appendices 1 to 1 that exclude a base station in which the transfer path is formed among a plurality of base stations, and calculate in order from a transfer path corresponding to a base station that forms a pair of base stations having a high degree of redundancy among the remaining base stations. The path control device according to any one of 7.
[Appendix 9]
Calculating a degree of overlap indicating a degree of overlap of characteristics between base stations;
Calculating a transfer path of a packet formed on a relay line between the base station and the network;
Setting a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
Including
The step of calculating the transfer route is a route control method of calculating the transfer route using the redundancy.
[Appendix 10]
A process of calculating the degree of overlap indicating the degree of overlap of characteristics between base stations;
A process for calculating a transfer path of a packet formed on a relay line between the base station and the network;
A process for setting a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
Is executed by the route control device,
The process for calculating the transfer path is a program for calculating the transfer path using the redundancy.
Note that the form of Supplementary Note 9 and the form of Supplementary Note 10 can be developed into the form of Supplementary Note 2 to the form of Supplementary Note 8, similarly to the form of Supplementary Note 1.

  Each disclosure of the cited patent documents and the like cited above is incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. In addition, various combinations or selections of various disclosed elements (including each element in each claim, each element in each embodiment or example, each element in each drawing, etc.) within the scope of the entire disclosure of the present invention. Is possible. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea. In particular, with respect to the numerical ranges described in this document, any numerical value or small range included in the range should be construed as being specifically described even if there is no specific description.

10, 10-1 to 10-4 Base station 20, 20-1 to 20-6 Transfer device 30 Base station management device 40 Backhaul management device 41 Communication unit 42 Network control unit 43 Traffic information management unit 44 Topology information management unit 45 Base station information management unit 51, 101 Redundancy calculation unit 52, 102 Route calculation unit 53, 103 Route setting unit 60 Integrated controller 100 Route control device 201-204 Cover area 301-304, 304a, 401-404 Transfer route

Claims (10)

And the multiplicity calculation section in which a plurality of base stations each coverage area to leave calculate the area of overlap as heavy Fukudo,
A route calculation unit for calculating a transfer route of a packet formed on a relay line between the base station and the network;
A path setting unit that sets a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
With
The route calculation unit is a route control device that calculates the transfer route using the redundancy.   The path control device according to claim 1, wherein the path calculation unit calculates in order from the transfer path corresponding to the base stations forming the base station pair having the high redundancy. The route calculation unit
The path control device according to claim 1 or 2, wherein a transfer path for setting a detour path is selected from the transfer paths affected by a link failure or a transmission rate decrease using the redundancy.   The path calculator, when selecting a transfer path for setting the detour path, if there are a plurality of base stations that are affected by the link failure or transmission rate reduction, The path control device according to claim 3, wherein the detour path corresponding to the base station having a low degree of overlap with the base station is preferentially calculated. A degree-of-duplication calculation unit that calculates the number of connected users in the overlapping area of each of the plurality of base stations as the degree of overlap;
A route calculation unit for calculating a transfer route of a packet formed on a relay line between the base station and the network;
A path setting unit that sets a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
With
The route calculation unit is a route control device that calculates the transfer route using the redundancy.   When calculating the transfer path corresponding to the base station forming the base station pair for which the degree of redundancy is calculated, the path calculation unit does not link the transfer paths corresponding to the base stations forming the base station pair with each other. The path control apparatus according to claim 1, wherein the transfer path is calculated so as to be shared.   The path calculation unit reflects the degree of duplication between the base station in which the transfer path is formed and the base station for which the transfer path is calculated, in the link cost of the relay line, and also reflects the degree of duplication. The path control device according to claim 1, wherein a transfer path corresponding to a base station for which the transfer path is calculated is calculated using the determined link cost. The route calculation unit
The base station in which the said transfer path | route was formed is excluded among several base stations, and it calculates in an order from the transfer path | route corresponding to the base station which makes the base station pair with the said high duplication degree among remaining base stations. The path control device according to any one of claims 1 to 7. A step in which a plurality of base stations each coverage area to leave calculate the area of overlap as heavy Fukudo,
Calculating a transfer path of a packet formed on a relay line between the base station and the network;
Setting a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
Including
The step of calculating the transfer route is a route control method of calculating the transfer route using the redundancy. A process of calculating the overlapping area of each of the plurality of base stations as the overlapping degree,
A process for calculating a transfer path of a packet formed on a relay line between the base station and the network;
A process for setting a processing rule according to the transfer path to a transfer apparatus included in the transfer path among a plurality of transfer apparatuses forming the relay line;
Is executed by the route control device,
The process for calculating the transfer path is a program for calculating the transfer path using the redundancy.

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