CN104753795B

CN104753795B - A kind of random network topology structure generation method and device

Info

Publication number: CN104753795B
Application number: CN201310745712.1A
Authority: CN
Inventors: 许胜�; 付斌章; 陈明宇; 张立新
Original assignee: Huawei Technologies Co Ltd; Institute of Computing Technology of CAS
Current assignee: Huawei Technologies Co Ltd; Institute of Computing Technology of CAS
Priority date: 2013-12-30
Filing date: 2013-12-30
Publication date: 2018-05-11
Anticipated expiration: 2033-12-30
Also published as: CN104753795A

Abstract

The application provides a kind of random network topology structure generation method and device, the average path length of each node in existing network is calculated, determines a first node of average path length minimum and a section point of average path length maximum；In the node being connected directly with the first node, the 3rd node of average path length minimum is determined；In the node being connected directly with the section point, a fourth node of average path length maximum, and the 5th node being directly connected to each other and the 6th node are determined；Three alternative on-positions are determined according to above-mentioned definite node, and the on-position that a position is equipment to be accessed is then determined from three alternative on-positions.Calculation amount is saved, improves the formation speed of random network topology structure.

Description

Irregular network topology structure generation method and device

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for generating a random network topology.

Background

The topology of the network is classified into a regular topology and a random topology, wherein the network of the random topology is widely concerned due to its better network characteristics.

A commonly used method for generating an irregular network topology structure at present is to select two device nodes (for short, nodes) multiple times by a random selection method on an existing network when new devices need to be added, access a device to be accessed between the two selected nodes, then calculate the overall performance of the connected network (the performance parameter is generally the average path length of the whole network), and select a connection with the best performance as a device connection from the calculation results selected multiple times randomly.

The device accessing the network usually has a plurality of ports capable of accessing the network, and only two ports are selected each time the device accesses the network, so that if a complete access network of one device needs to select an access position for a plurality of times, it can be seen that the device to be accessed can be completely accessed to the network by applying the current irregular network topology generation method and requiring a plurality of random calculations, so that the irregular network topology generation speed is relatively slow.

Disclosure of Invention

The embodiment of the invention provides a method and a device for generating a random network topology structure, which are used for improving the generation speed of the random network topology structure.

A first aspect of the present invention provides a method for generating a random network topology, including:

calculating the average shortest path length of each node in the existing network;

determining a first node with the minimum average shortest path length and a second node with the maximum average shortest path length; determining a third node with the minimum average shortest path length among nodes directly connected with the first node; determining a fourth node with the largest average shortest path length among the nodes directly connected with the second node; determining a fifth node and a sixth node which are directly connected with each other among the nodes which are directly connected with the second node;

taking a position between the first node and the third node as a first alternative access position of the equipment to be accessed; disconnecting the connection between the first node and the third node and the connection between the second node and the fourth node, connecting the first node and the second node, and taking the position between the third node and the fourth node as a second alternative access position of the device to be accessed; taking the position between the fifth node and the sixth node as a third alternative access position of the equipment to be accessed;

and determining one position as the access position of the equipment to be accessed in the three alternative access positions.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the determining, from among the three alternative access locations, one location as the access location of the device to be accessed includes:

respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to one of the three alternative access positions;

and determining the candidate access position with the minimum average shortest path length of the whole network as the access position of the equipment to be accessed.

With reference to the first aspect, in a third possible implementation manner of the first aspect, the determining, in the three alternative access locations, one location as the access location of the device to be accessed includes:

judging whether the first alternative access position is available;

if the access position is unavailable, respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the second alternative access position and the third alternative access position as the access position of the equipment to be accessed;

and if the first alternative access position is available, taking the first alternative access position as the access position of the equipment to be accessed.

With reference to the first aspect, in a fourth possible implementation manner of the first aspect, the determining, in the three alternative access locations, one location as the access location of the device to be accessed includes:

determining whether the third alternative access location is available;

if the access position is unavailable, respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the second alternative access position as the access position of the equipment to be accessed;

and if the third alternative access position is available, taking the third alternative access position as the access position of the equipment to be accessed.

With reference to the first aspect, in a fifth possible implementation manner of the first aspect, the determining, from among the three alternative access locations, one location as the access location of the device to be accessed includes:

judging whether a connection relation exists between the first node and the second node before the first node and the second node are connected, if so, executing a first step, otherwise, executing a second step;

the first step is as follows: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position as the access position of the equipment to be accessed;

the second step is as follows: and judging whether the second alternative access position is available, if not, executing a first step, and if so, taking the second alternative access position as the access position of the equipment to be accessed.

With reference to the first aspect, in a sixth possible implementation manner of the first aspect, the determining, in the three alternative access locations, one location as the access location of the device to be accessed includes:

determining whether the first alternative access location and the second alternative access location are available;

if the first alternative access position and the second alternative access position are not available, taking the third alternative access position as the access position of the equipment to be accessed;

if only one alternative access position is available from the first alternative access position and the second alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

if the first alternative access position and the second alternative access position are both available, respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the second alternative access position as the access position of the equipment to be accessed.

With reference to the first aspect, in a seventh possible implementation manner of the first aspect, the determining, in the three alternative access locations, one location as the access location of the device to be accessed includes:

determining whether the first alternative access location and the third alternative access location are available;

if the first alternative access position and the third alternative access position are not available, taking the second alternative access position as the access position of the equipment to be accessed;

if only one alternative access position is available from the first alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

if the first alternative access position and the third alternative access position are both available, respectively calculating an average shortest path length of the whole network after the device to be accessed is accessed to the first alternative access position and an average shortest path length of the whole network after the device to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position as the access position of the device to be accessed.

With reference to the first aspect, in an eighth possible implementation manner of the first aspect, the determining, in the three alternative access locations, one location as the access location of the device to be accessed includes:

determining whether the second alternative access location and the third alternative access location are available;

if the second alternative access position and the third alternative access position are not available, taking the first alternative access position as the access position of the equipment to be accessed;

if only one alternative access position is available from the second alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

if the second alternative access position and the third alternative access position are both available, respectively calculating an average shortest path length of the whole network after the device to be accessed is accessed to the second alternative access position and an average shortest path length of the whole network after the device to be accessed is accessed to the third alternative access position, and using the alternative access position with the minimum average shortest path length of the whole network in the second alternative access position and the third alternative access position as the access position of the device to be accessed.

A second aspect of the present invention provides an apparatus for generating a random network topology, including:

the calculation module is used for calculating the average shortest path length of each node in the existing network;

the characteristic node determining module is used for determining a first node with the minimum average shortest path length and a second node with the maximum average shortest path length; determining a third node with the minimum average shortest path length among nodes directly connected with the first node; determining a fourth node with the largest average shortest path length among the nodes directly connected with the second node; determining a fifth node and a sixth node which are directly connected with each other among the nodes which are directly connected with the second node;

the alternative access position determining module is used for taking the position between the first node and the third node as a first alternative access position of the equipment to be accessed; disconnecting the connection between the first node and the third node and the connection between the second node and the fourth node, connecting the first node and the second node, and taking the position between the third node and the fourth node as a second alternative access position of the device to be accessed; taking the position between the fifth node and the sixth node as a third alternative access position of the equipment to be accessed;

and the access position determining module is used for determining one position from the three alternative access positions as the access position of the equipment to be accessed.

With reference to the second aspect, in a second possible implementation manner of the second aspect, the access location determining module includes:

the first calculation unit is used for calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to one of the three alternative access positions;

and the first access position determining unit is used for determining the alternative access position with the minimum average shortest path length of the whole network as the access position of the equipment to be accessed.

With reference to the second aspect, in a third possible implementation manner of the second aspect, the access location determining module includes:

a first judging unit, configured to judge whether the first alternative access location is available;

a second access position determining unit, configured to, when the first determining unit determines that the first candidate access position is not available, respectively calculate an average shortest path length of the entire network after the device to be accessed is accessed to the second candidate access position and an average shortest path length of the entire network after the device to be accessed is accessed to the third candidate access position, and use, as the access position of the device to be accessed, an alternative access position, from the second candidate access position and the third candidate access position, at which the average shortest path length of the entire network is the smallest; and if the first judging unit judges that the first alternative access position is available, the first alternative access position is used as the access position of the equipment to be accessed.

With reference to the second aspect, in a fourth possible implementation manner of the second aspect, the access location determining module includes:

a second determining unit, configured to determine whether the third alternative access location is available;

a third access position determining unit, configured to, when the second determining unit determines that the third alternative access position is not available, respectively calculate an average shortest path length of the entire network after the device to be accessed is accessed to the first alternative access position and an average shortest path length of the entire network after the device to be accessed is accessed to the second alternative access position, and use, as the access position of the device to be accessed, an alternative access position, from the first alternative access position and the second alternative access position, at which the average shortest path length of the entire network is the smallest; and if the second judging unit judges that the third alternative access position is available, taking the third alternative access position as the access position of the equipment to be accessed.

With reference to the second aspect, in a fifth possible implementation manner of the second aspect, the access location determining module includes:

a third judging unit configured to judge whether a connection relationship already exists between the first node and the second node before the first node and the second node are connected;

a fourth judging unit, configured to judge whether the second alternative access location is available when the third judging unit judges that a connection relationship does not exist between the first node and the second node;

a fourth access position determining unit, configured to use the second alternative access position as the access position of the device to be accessed when the fourth determining unit determines that the second alternative access position is available; when the third judging unit judges that a connection relationship exists between the first node and the second node, or when the fourth judging unit judges that the second alternative access position is unavailable, the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position are respectively calculated, and the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position is used as the access position of the equipment to be accessed.

With reference to the second aspect, in a sixth possible implementation manner of the second aspect, the access location determining module includes:

a fifth determining unit, configured to determine whether the first alternative access location and the second alternative access location are available;

a fifth access position determining unit, configured to, when the fifth determining unit determines that both the first candidate access position and the second candidate access position are unavailable, use the third candidate access position as the access position of the device to be accessed; when the fifth judging unit judges that only one alternative access position is available from the first alternative access position and the second alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the fifth judging unit judges that both the first candidate access position and the second candidate access position can be used, the average shortest path length of the whole network after the device to be accessed is accessed to the first candidate access position and the average shortest path length of the whole network after the device to be accessed is accessed to the second candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the whole network in the first candidate access position and the second candidate access position is used as the access position of the device to be accessed.

With reference to the second aspect, in a seventh possible implementation manner of the second aspect, the access location determining module includes:

a sixth determining unit configured to determine whether the first alternative access position and the third alternative access position are available;

a sixth access position determining unit, configured to, when the sixth determining unit determines that both the first candidate access position and the third candidate access position are unavailable, use the second candidate access position as the access position of the device to be accessed; when the sixth judging unit judges that only one alternative access position is available from the first alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the sixth judging unit judges that both the first candidate access position and the third candidate access position are available, the average shortest path length of the whole network after the device to be accessed is accessed to the first candidate access position and the average shortest path length of the whole network after the device to be accessed is accessed to the third candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the whole network in the first candidate access position and the third candidate access position is taken as the access position of the device to be accessed.

With reference to the second aspect, in an eighth possible implementation manner of the second aspect, the access location determining module includes:

a seventh determining unit for determining whether the second alternative access position and the third alternative access position are available;

a seventh access position determining unit, configured to, when the seventh determining unit determines that both the second alternative access position and the third alternative access position are unavailable, use the first alternative access position as the access position of the device to be accessed; when the seventh judging unit judges that only one alternative access position is available from the second alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the seventh determining unit determines that both the second candidate access position and the third candidate access position are available, the average shortest path length of the entire network after the device to be accessed is accessed to the second candidate access position and the average shortest path length of the entire network after the device to be accessed is accessed to the third candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the entire network in the second candidate access position and the third candidate access position is used as the access position of the device to be accessed.

A third aspect of the present invention provides an apparatus for generating a random network topology, including: at least one processor and a memory coupled with the at least one processor; wherein,

the at least one processor is configured to:

With reference to the third aspect, in a second possible implementation manner of the third aspect, the at least one processor configured to determine one of the three alternative access locations as the access location of the device to be accessed is further configured to:

With reference to the third aspect, in a third possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

judging whether the first alternative access position is available;

With reference to the third aspect, in a fourth possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

determining whether the third alternative access location is available;

With reference to the third aspect, in a fifth possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

With reference to the third aspect, in a sixth possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

if only one alternative access position is available in the first alternative access position and the second alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

With reference to the third aspect, in a seventh possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

if only one alternative access position is available in the first alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

With reference to the third aspect, in an eighth possible implementation manner of the third aspect, the at least one processor configured to determine, among the three alternative access locations, one location as the access location of the device to be accessed is further configured to:

if only one alternative access position is available in the second alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed;

The embodiment of the invention provides a method and a device for generating a random network topological structure, which are used for calculating the average shortest path length of each node in the existing network, and determining a first node with the minimum average shortest path length and a second node with the maximum average shortest path length; determining a third node with the minimum average shortest path length among nodes directly connected with the first node; determining a fourth node with the largest average shortest path length among the nodes directly connected with the second node, and a fifth node and a sixth node which are directly connected with each other; and determining three alternative access positions according to the determined nodes, and then determining one position from the three alternative access positions as the access position of the equipment to be accessed.

Therefore, the method and the device for generating the irregular network topology structure provided by the embodiment of the application directly determine the access position of the device to be accessed in the network by using the current network characteristics, and, determining a position to be accessed of the equipment to be accessed, calculating the average shortest path length of the whole network at most three times, for the method of determining the access position in a random manner, in order to ensure that a better position is selected, determining a position to be accessed of a device to be accessed requires calculating the average shortest path length of the whole network for many times, and therefore, under the condition that the calculation methods of the average shortest path length of the whole network are the same, the random network topology structure generation method and the random network topology structure generation device provided by the application have the advantages that the calculation amount for directly searching the access position of the new equipment node by utilizing the network characteristics is small, so that the calculation amount is saved, and the generation speed of the random network topology structure is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flowchart of a method for generating a random network topology according to an embodiment of the present application;

fig. 2 is a schematic diagram of determining a first alternative access location provided by an embodiment of the present application;

fig. 3 is a schematic diagram of determining a second alternative access location provided by an embodiment of the present application;

fig. 4 is a schematic diagram of determining a third alternative access location provided by an embodiment of the present application;

fig. 5 is a flowchart of an implementation method for determining one of three alternative access positions as an access position of the device to be accessed according to an embodiment of the present application;

fig. 6 is a flowchart of another implementation method for determining one of three alternative access positions as an access position of the device to be accessed according to the embodiment of the present application;

fig. 7 is a flowchart of another implementation method for determining one of three alternative access locations as an access location of the device to be accessed according to an embodiment of the present application;

fig. 8 is a flowchart of another implementation method for determining one of three alternative access locations as an access location of the device to be accessed according to an embodiment of the present application;

fig. 9 is a flowchart of another implementation method for determining one of three alternative access locations as an access location of the device to be accessed according to an embodiment of the present application;

fig. 10 is a flowchart of a further implementation method for determining one of three alternative access positions as an access position of the device to be accessed according to an embodiment of the present application;

fig. 11 is a flowchart of another implementation method for determining one of three alternative access positions as an access position of the device to be accessed according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a random network topology generating apparatus according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of an access location determining module according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of an access position determining module according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of an access location determining module according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of an access location determining module according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of an access position determining module according to an embodiment of the present application;

fig. 18 is a schematic structural diagram of an access location determining module according to an embodiment of the present application;

fig. 19 is a schematic structural diagram of an access position determining module according to an embodiment of the present application;

fig. 20 is a schematic structural diagram of another random network topology generating device according to an embodiment of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be practiced otherwise than as specifically illustrated.

Detailed Description

So that those skilled in the art can further understand the features and technical content of the present invention, reference is made to the following detailed description of the present invention and accompanying drawings, which are provided for reference and illustration only and are not intended to limit the present invention.

Referring to fig. 1, fig. 1 is a flowchart of a method for generating a random network topology according to an embodiment of the present application, where the method includes:

step S11, calculating the average shortest path length of each node in the existing network;

the existing network refers to a built network, and the existing network can be in a regular network topology structure or a random network topology structure. In the embodiment of the application, when a new device is accessed in the existing network, the average shortest path length of each node in the existing network is calculated.

In the embodiment of the present application, for a certain node u in the existing network, an average value of shortest path lengths between the node u and any other node except the node u in the existing network is determined as an average shortest path length of the node u.

There are many algorithms for the shortest path length of the node u, for example, a florode algorithm (Floyd algorithm) may be selected for obtaining, a dickstra algorithm (Dijkstra algorithm) may also be selected for obtaining, and of course, the shortest path length may also be obtained by other algorithms, which is not described herein.

Step S12: determining a first node with the minimum average shortest path length and a second node with the maximum average shortest path length; determining a third node with the minimum average shortest path length among nodes directly connected with the first node; determining a fourth node with the largest average shortest path length among the nodes directly connected with the second node; determining a fifth node and a sixth node which are directly connected with each other among the nodes which are directly connected with the second node;

in the embodiment of the application, characteristic nodes, namely a first node, a second node, a third node, a fourth node, a fifth node and a sixth node, are determined according to the average shortest path length of each node.

Step S13: taking a position between the first node and the third node as a first alternative access position of the equipment to be accessed; disconnecting the connection between the first node and the third node and the connection between the second node and the fourth node, connecting the first node and the second node, and taking the position between the third node and the fourth node as a second alternative access position of the device to be accessed; taking the position between the fifth node and the sixth node as a third alternative access position of the equipment to be accessed;

the method of determining alternative access locations is described below in conjunction with fig. 2-4:

referring to fig. 2, fig. 2 is a schematic diagram for determining a first alternative access location according to an embodiment of the present application. In fig. 2-a, it is assumed that node a is the node with the smallest average shortest path length, and node B, node C, and node D are the nodes directly connected to node a. The method for determining the alternative access position provided by the embodiment of the application comprises the following steps: and determining a node with the minimum average shortest path length from the node B, the node C and the node D, and assuming that the node D is determined to be the node with the minimum average shortest path length through calculation, taking the position between the node a and the node D as an alternative access position, as shown in fig. 2-B, and the node E is a node to be accessed (i.e., a device to be accessed).

Referring to fig. 3, fig. 3 is a schematic diagram for determining a second alternative access position according to an embodiment of the present application. In fig. 3-a, it is assumed that node a is the node with the smallest average shortest path length, node B is the node with the largest average shortest path length, node C is the node with the largest average shortest path length among the nodes directly connected to node B, and node D is the node with the smallest average shortest path length among the nodes directly connected to node a. Another method for determining alternative access positions provided in the embodiments of the present application is: disconnecting the connection between the node a and the node D, disconnecting the connection between the node B and the node C, connecting the node a and the node B, and using the position between the node C and the node D as an alternative access position, as shown in fig. 3-B, the node E is a node to be accessed.

Referring to fig. 4, fig. 4 is a schematic diagram for determining a third alternative access position according to an embodiment of the present application. In fig. 4-a, it is assumed that node a is the node with the largest average shortest path length, and node B, node C, and node D are nodes directly connected to node a. Another method for determining alternative access locations provided in the embodiments of the present application is: two nodes directly connected are determined from the node B, the node C and the node D, and if the two nodes are the node C and the node D, the position between the node C and the node D is used as an alternative access position, as shown in fig. 2-B, and the node E is a node to be accessed.

It should be noted that, in the embodiment of the present application, all feature nodes (i.e., the first node to the sixth node) are determined first, and then the candidate access positions are determined according to the determined feature nodes, and the methods for determining the candidate access positions provided by the present application are different according to the difference of the used feature nodes, so in the implementation of the present application, after a part of the nodes are determined, the corresponding candidate access positions may be determined, for example, after the third node is determined, the position between the first node and the third node may be used as the first candidate access position of the device to be accessed, and it is not necessary to wait for the fourth node or the fifth and sixth nodes to determine the first candidate node.

Step S14: and determining one position as the access position of the equipment to be accessed in the three alternative access positions.

There are many methods for determining one position as the access position of the device to be accessed in the three alternative access positions, for example, after the device to be accessed is accessed to the network according to the three alternative access positions, the length of the average shortest path of the whole network under a new structure is calculated, and the alternative access position with the minimum length of the average shortest path of the whole network is selected as the access position of the device to be accessed; or, taking one of the three alternative access positions as a main part, and under the condition that the access position meeting the condition cannot be obtained, selecting the other two methods for calculation, and taking the result obtained after calculation as the access position of the equipment to be accessed; or, two of the three alternative access positions may be used as the main points, and when an access position satisfying the condition is not obtained, the other method is selected for calculation, and the result obtained after calculation is used as the access position of the device to be accessed.

After the access position is determined, when the equipment to be accessed is accessed to the determined position, if the two nodes corresponding to the determined access position have direct connection, the direct connection is disconnected, and then the equipment to be accessed is directly connected with the two nodes.

The irregular network topology structure generation method provided by the embodiment of the application directly determines the access position of the device to be accessed in the network by utilizing the characteristics of the current network (namely, the existing network), and, determining one to-be-accessed position of the to-be-accessed device, calculating the average shortest path length of the whole network at most 3 times, for the method of determining the access position in a random manner, in order to ensure that a better position is selected, determining a position to be accessed of a device to be accessed requires calculating the average shortest path length of the whole network for many times, and therefore, under the condition that the calculation methods of the average shortest path length of the whole network are the same, the random network topology structure generation method provided by the application directly searches the access position of the new equipment node by using the network characteristics, and the calculation amount is small, so that the calculation amount is saved, and the generation speed of the random network topology structure is improved. Meanwhile, as the spare port is not reserved for network expansion, the device port is effectively utilized.

Further, in the embodiment of the present application, the alternative access position of the device to be accessed is determined according to the performance parameter of the current network (average shortest path length of a single node), so that under the same condition (for example, under the condition that the number of devices, the sequence of accessing the devices to the network, and the specification of the devices are all the same), the network topology structure obtained by applying the random network topology structure generation method provided by the present application is fixed, rather than random, that is, under the condition that the networking condition is determined (for example, the number of devices, the sequence of accessing the devices to the network, and the specification of the devices are all determined), if the devices are networked by using the random network topology structure generation method provided by the embodiment of the present application for many times, the topology structures of the obtained networks are necessarily the same. Therefore, if only the attribute information of the device (such as the number of devices, the specification of the device, the port number of the device, and the like) is stored, the topology of the previous network can be obtained through calculation, so that the access position of the new device can be calculated without storing the topology of the previous network when the network is expanded.

In addition, the network topology structure obtained by the method provided by the embodiment of the application has better stability and balance, namely the variance between the average shortest path lengths of each node in the generated network topology structure is small, so that the performance of the network is better ensured.

In the foregoing embodiment, preferably, a flowchart of an implementation method for determining one of three alternative access positions as the access position of the device to be accessed, provided by the embodiment of the present application, is shown in fig. 5, and may include:

step S51: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to one of the three alternative access positions;

specifically, after the device to be accessed is accessed to the first alternative access position, the average shortest path length of the whole network is calculated and recorded as the first average shortest path length of the whole network for the convenience of distinguishing;

calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position, and marking as the second average shortest path length of the whole network for the convenience of distinguishing;

and calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and recording the average shortest path length as the third average shortest path length of the whole network for the convenience of distinguishing.

The average shortest path of the entire network may refer to an average of average shortest path lengths of all nodes in the entire network.

Step S52: and determining the candidate access position with the minimum average shortest path length of the whole network as the access position of the equipment to be accessed.

And taking the alternative access position corresponding to the minimum value of the first average shortest path length, the second average shortest path length and the third average shortest path length of the whole network as the access position of the equipment to be accessed.

In this embodiment of the application, in order to optimize the embodiment shown in fig. 5, for each alternative access position, before accessing the device to be accessed to the alternative access position, the method may further include:

judging whether the equipment to be accessed has a connection relation with at least one node in two nodes corresponding to the alternative access position;

if yes, the step of calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the alternative access position is not executed;

if not, the access position is available, and then the step of calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the alternative access position is executed;

a flowchart of another implementation method for determining one position as the access position of the device to be accessed from among three alternative access positions provided in the embodiment of the present application is shown in fig. 6, and may include:

step S61: judging whether the first alternative access position is available, if so, executing the step S62, otherwise, executing the step S63;

whether the first alternative access position is available or not can be judged by the following method:

judging that a connection relation exists between the equipment to be accessed and the first node or the third node, and if so, determining that the first alternative access position is unavailable; otherwise, determining that the first alternative access location is available.

Step S62: and taking the first alternative access position as the access position of the equipment to be accessed.

Step S63: and respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the second alternative access position and the third alternative access position as the access position of the equipment to be accessed.

In the embodiment of the application, a first alternative access position is used as a main access position, a second alternative access position and a third alternative access position are both used as standby access positions, when the first alternative access position is available, the first alternative access position is directly used as an access position of a device to be accessed, and when the first alternative access position is unavailable, one access position is determined from the second alternative access position and the third alternative access position to be used as the access position of the device to be accessed.

Fig. 7 shows a flowchart of another implementation method for determining one of three alternative access positions as the access position of the device to be accessed, where the implementation method includes:

step S71: judging whether the third alternative access position is available, if so, executing the step S72, otherwise, executing the step S73;

whether the third alternative access location is available or not may be determined by:

judging that a connection relation exists between the equipment to be accessed and the fifth node or the sixth node, and if so, determining that the third alternative access position is unavailable; otherwise, determining that the third alternative access location is available.

Step S72: taking the third alternative access position as an access position of the equipment to be accessed;

step S73: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the second alternative access position as the access position of the equipment to be accessed.

In the embodiment of the present application, a third alternative access position is used as a main access position, and both the first alternative access position and the second alternative access position are used as standby access positions, when the third alternative access position is available, the third alternative access position is directly used as an access position of a device to be accessed, and when the third alternative access position is unavailable, one access position is determined from the first alternative access position and the second alternative access position as an access position of the device to be accessed.

Fig. 8 shows a flowchart of another implementation method for determining one of three alternative access positions as the access position of the device to be accessed, where the implementation method includes:

step S81: judging whether a connection relationship already exists between the first node and the second node before the first node and the second node are connected, if so, executing step S83, otherwise, executing step S82;

step S82: judging whether the second alternative access position is available, if so, executing step S84; otherwise, go to step S83;

the determination of whether the second alternative access location is available may be determined by:

judging whether a connection relation already exists between the equipment to be accessed and the third node or the fourth node, and if so, determining that the second alternative access position is unavailable; otherwise, determining that the third alternative access location is available.

Step S83: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position as the access position of the equipment to be accessed.

Step S84: and taking the second alternative access position as the access position of the equipment to be accessed.

In the embodiment of the application, the second alternative access position is used as the main access position, the first alternative access position and the third alternative access position are both used as the standby access positions, when the second alternative access position is available, the second alternative access position is directly used as the access position of the device to be accessed, and when the second alternative access position is unavailable, one access position is determined from the first alternative access position and the third alternative access position to be used as the access position of the device to be accessed.

Fig. 9 shows a flowchart of another implementation method for determining one of three alternative access positions as the access position of the device to be accessed, where the implementation method includes:

step S91: determining whether the first alternative access location and the second alternative access location are available, and if the first alternative access location and the second alternative access location are not available, performing step S92; if only one of the first and second alternative access locations is available, performing step S93; otherwise, go to step S94;

in the embodiment of the present application, determining whether the second candidate access location is available may be determined from two aspects: on the one hand, before connecting the first node and the second node, if a connection relationship already exists between the first node and the second node, the second alternative access location is not available; on the other hand, if there is already a connection relationship between the device to be accessed and the third or fourth node, the second alternative access location is also not available.

Step S92: and taking the third alternative access position as the access position of the equipment to be accessed.

Step S93: and using the available alternative access position as the access position of the equipment to be accessed.

Namely, if only the first alternative access position is available, the first alternative access position is taken as the access position of the equipment to be accessed; and if only a second alternative access position is available, using the second alternative access position as the access position of the equipment to be accessed.

Step S94: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the second alternative access position as the access position of the equipment to be accessed.

In the embodiment of the present application, two positions, namely, a first candidate access position and a second candidate access position, are used as main access positions, and a third candidate access position is used as a standby access position, when a device to be accessed is accessed to a network, the first candidate access position and the second candidate access position are preferably selected as access positions of the device to be accessed, and only when the first candidate access position and the second candidate access position are both unavailable, the third candidate access position is used as an access position of the device to be accessed.

Fig. 10 shows a flowchart of still another implementation method for determining one of three alternative access positions as the access position of the device to be accessed, where the implementation method includes:

step S101: determining whether the first alternative access location and the third alternative access location are available, and if the first alternative access location and the third alternative access location are not available, performing step S102; if only one of the first alternative access location and the third alternative access location is available, performing step S103; otherwise, executing step S104;

step S102: and taking the second alternative access position as the access position of the equipment to be accessed.

Step S103: and taking the available alternative access position as the access position of the equipment to be accessed.

Step S104: respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position as the access position of the equipment to be accessed.

In the embodiment of the present application, two positions, namely, a first candidate access position and a third candidate access position, are used as main access positions, and a second candidate access position is used as a standby access position, when a device to be accessed is accessed to a network, the first candidate access position and the third candidate access position are preferably selected as access positions of the device to be accessed, and only when the first candidate access position and the third candidate access position are both unavailable, the second candidate access position is used as an access position of the device to be accessed.

Fig. 11 shows a flowchart of another implementation method for determining one of three alternative access positions as the access position of the device to be accessed, where the implementation method includes:

step S111: determining whether the second alternative access location and the third alternative access location are available, and if the second alternative access location and the third alternative access location are not available, performing step S112; if only one of the second alternative access location and the third alternative access location is available, performing step S113; otherwise, go to step S114;

step S112: and taking the first alternative access position as the access position of the equipment to be accessed.

Step S113: and using the available alternative access position as the access position of the equipment to be accessed.

Step S114: and respectively calculating the average shortest path length of the whole network after the equipment to be accessed is accessed to the second alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position, and taking the alternative access position with the minimum average shortest path length of the whole network in the second alternative access position and the third alternative access position as the access position of the equipment to be accessed.

In the embodiment of the present application, two positions, namely, a second alternative access position and a third alternative access position, are used as main access positions, and a first alternative access position is used as a standby access position, when a device to be accessed is accessed to a network, the second alternative access position and the third alternative access position are preferably selected as access positions of the device to be accessed, and only when the second alternative access position and the third alternative access position are both unavailable, the first alternative access position is used as an access position of the device to be accessed.

It should be noted that, when there are multiple ports in the device to be accessed, the access positions of two ports (for convenience of description, two ports are hereinafter referred to as a group of ports) can be obtained by using the above method each time, and the above method calculation needs to be repeated multiple times for multiple groups of ports. When the device to be accessed has at least one group of ports to be accessed into the network, and the access positions of other ports of the device to be accessed are determined again according to the method, the network topology structure is changed, so that when the average shortest path length of each node in the network is calculated again, the device to be accessed is not included in the node range searched by the current network, namely, the average shortest path length of the device to be accessed is not calculated, and the device to be accessed cannot be used as any one node from a third node to a sixth node.

Corresponding to the method embodiment, an embodiment of the present application further provides a device for generating a random network topology, and a schematic structural diagram of the device for generating a random network topology provided by the embodiment of the present application is shown in fig. 12, and may include:

a calculation module 121, a feature node determination module 122, an alternative access position determination module 123 and an access position determination module 124; wherein,

the calculation module 121 is configured to calculate an average shortest path length of each node in the existing network;

the feature node determining module 122 is configured to determine a first node with the smallest average shortest path length and a second node with the largest average shortest path length; determining a third node with the minimum average shortest path length among nodes directly connected with the first node; determining a fourth node with the largest average shortest path length among the nodes directly connected with the second node; determining a fifth node and a sixth node which are directly connected with each other among the nodes which are directly connected with the second node;

the alternative access position determining module 123 is configured to use a position between the first node and the third node as a first alternative access position of the device to be accessed; disconnecting the connection between the first node and the third node and the connection between the second node and the fourth node, connecting the first node and the second node, and taking the position between the third node and the fourth node as a second alternative access position of the device to be accessed; taking the position between the fifth node and the sixth node as a third alternative access position of the equipment to be accessed;

the access position determining module 124 is configured to determine one position as the access position of the device to be accessed among the three alternative access positions.

The irregular network topology structure generation device provided by the embodiment of the application directly determines the access position of the equipment to be accessed in the network by utilizing the current network characteristics, and, determining one to-be-accessed position of the to-be-accessed device, calculating the average shortest path length of the whole network at most 3 times, for the method of determining the access position in a random manner, in order to ensure that a better position is selected, determining a position to be accessed of a device to be accessed requires calculating the average shortest path length of the whole network for many times, and therefore, under the condition that the calculation methods of the average shortest path length of the regular pole network are the same, the random network topology structure generation device provided by the application directly searches the access position of the new equipment node by using the network characteristics, and the calculation amount is small, so that the calculation amount is saved, and the generation speed of the random network topology structure is improved. Meanwhile, the equipment port is effectively utilized.

Further, in the embodiment of the present application, the alternative access position of the device to be accessed is determined according to the performance parameter of the current network (the average shortest path length of a single node), so that the network topology structure obtained under the same condition is fixed, and therefore, the access position of the new device can be calculated without storing the previous network topology structure diagram when the network is expanded.

In addition, the network topology structure obtained by the device provided by the embodiment of the application has better stability and balance, namely the variance between the average shortest path lengths of each node in the generated network topology structure is small, so that the performance of the network is better ensured.

In the above embodiment, preferably, a schematic structural diagram of the access location determining module 124 is shown in fig. 13, and may include:

the first calculating unit 131 is configured to calculate an average shortest path length of the entire network after the to-be-accessed device is accessed to one of the three alternative access positions;

a first access location determining unit 132, configured to determine, as the access location of the device to be accessed, the candidate access location where the average shortest path length of the entire network is the smallest.

Another schematic structural diagram of the access position determining module 124 provided in the embodiment of the present application is shown in fig. 14, and may include:

a first judging unit 141, configured to judge whether the first alternative access location is available;

a second access position determining unit 142, configured to, when the first determining unit 141 determines that the first candidate access position is not available, respectively calculate an average shortest path length of the entire network after the to-be-accessed device is accessed to the second candidate access position and an average shortest path length of the entire network after the to-be-accessed device is accessed to the third candidate access position, and use, as the access position of the to-be-accessed device, an alternative access position of the second candidate access position and the third candidate access position, where the average shortest path length of the entire network is the smallest; and if the first judging unit judges that the first alternative access position is available, the first alternative access position is used as the access position of the equipment to be accessed.

Fig. 15 is a schematic structural diagram of the access location determining module 124 provided in the embodiment of the present application, which may include:

a second determining unit 151, configured to determine whether the third alternative access location is available;

a third access position determining unit 152, configured to, when the second determining unit determines that the third candidate access position is not available, respectively calculate an average shortest path length of the entire network after the to-be-accessed device is accessed to the first candidate access position and an average shortest path length of the entire network after the to-be-accessed device is accessed to the second candidate access position, and use, as the access position of the to-be-accessed device, an candidate access position of the first candidate access position and the second candidate access position, where the average shortest path length of the entire network is the smallest; and if the second judging unit judges that the third alternative access position is available, taking the third alternative access position as the access position of the equipment to be accessed.

Fig. 16 shows another schematic structural diagram of the access location determining module 124 according to an embodiment of the present application, which may include:

a third judging unit 161 configured to judge whether a connection relationship already exists between the first node and the second node when the first node and the second node are connected;

a fourth determining unit 162, configured to determine whether the second alternative access location is available when the third determining unit determines that the connection relationship does not exist between the first node and the second node;

a fourth access position determining unit 163, configured to use the second alternative access position as the access position of the device to be accessed when the fourth determining unit determines that the second alternative access position is available; when the third judging unit judges that a connection relationship exists between the first node and the second node, or when the fourth judging unit judges that the second alternative access position is unavailable, the average shortest path length of the whole network after the equipment to be accessed is accessed to the first alternative access position and the average shortest path length of the whole network after the equipment to be accessed is accessed to the third alternative access position are respectively calculated, and the alternative access position with the minimum average shortest path length of the whole network in the first alternative access position and the third alternative access position is used as the access position of the equipment to be accessed.

Fig. 17 shows another schematic structural diagram of the access location determining module 124 according to the embodiment of the present application, which may include:

a fifth determining unit 171, configured to determine whether the first alternative access position and the second alternative access position are available;

a fifth access position determining unit 172, configured to, when the fifth determining unit determines that the first candidate access position and the second candidate access position are both unavailable, use the third candidate access position as the access position of the device to be accessed; when the fifth judging unit judges that only one alternative access position is available from the first alternative access position and the second alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the fifth judging unit judges that both the first candidate access position and the second candidate access position can be used, the average shortest path length of the whole network after the device to be accessed is accessed to the first candidate access position and the average shortest path length of the whole network after the device to be accessed is accessed to the second candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the whole network in the first candidate access position and the second candidate access position is used as the access position of the device to be accessed.

Fig. 18 shows another schematic structural diagram of the access location determining module 124 according to the embodiment of the present application, which may include:

a sixth determining unit 181, configured to determine whether the first alternative access location and the third alternative access location are available;

a sixth accessing position determining unit 182, configured to, when the sixth determining unit determines that the first candidate accessing position and the third candidate accessing position are both unavailable, take the second candidate accessing position as the accessing position of the device to be accessed; when the sixth judging unit judges that only one alternative access position is available from the first alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the sixth judging unit judges that both the first candidate access position and the third candidate access position are available, the average shortest path length of the whole network after the device to be accessed is accessed to the first candidate access position and the average shortest path length of the whole network after the device to be accessed is accessed to the third candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the whole network in the first candidate access position and the third candidate access position is taken as the access position of the device to be accessed.

Fig. 19 shows another schematic structural diagram of the access location determining module 124 according to the embodiment of the present application, which may include:

a seventh determining unit 191, configured to determine whether the second alternative access position and the third alternative access position are available;

a seventh access position determining unit 192, configured to use the first alternative access position as the access position of the device to be accessed when the seventh determining unit determines that the second alternative access position and the third alternative access position are both unavailable; when the seventh judging unit judges that only one alternative access position is available from the second alternative access position and the third alternative access position, taking the available alternative access position as the access position of the equipment to be accessed; when the seventh determining unit determines that both the second candidate access position and the third candidate access position are available, the average shortest path length of the entire network after the device to be accessed is accessed to the second candidate access position and the average shortest path length of the entire network after the device to be accessed is accessed to the third candidate access position are respectively calculated, and the candidate access position with the minimum average shortest path length of the entire network in the second candidate access position and the third candidate access position is used as the access position of the device to be accessed.

A schematic structural diagram of another irregular network topology generating device provided in the embodiment of the present application is shown in fig. 20, and may include:

at least one processor 201, a memory 202 coupled to the at least one processor 201, and a communication interface 204; the at least one processor 201, memory 202 and communication interface 204 communicate with each other via a communication bus 203. Wherein,

the at least one processor 201 is configured to:

Preferably, the processor configured to determine one of the three alternative access positions as the access position of the device to be accessed is further configured to:

The processor configured to determine one of the three alternative access positions as the access position of the device to be accessed is further configured to:

judging whether the first alternative access position is available;

determining whether the third alternative access location is available;

Specifically, the method disclosed in the above embodiments of the present invention may be applied to the processor 201, or implemented by the processor 201. The processor 201 may be an integrated circuit chip having signal processing capabilities. In the implementation process, the steps of the method may be implemented by an integrated logic circuit of hardware or an instruction in the form of software in the processor 201, which may be a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an array of programmable gate arrays (FPGA) or other programmable logic devices, a discrete gate or transistor logic device, a discrete hardware component, or the like, and may implement or perform the methods, steps, and logic blocks disclosed in the embodiments of the present invention. A general purpose processor may be a microprocessor or the processor may be any conventional processor, decoder, etc. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the field, such as a Random Access Memory (RAM), a Flash Memory, a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an electrically erasable and programmable Memory (EEPROM), a register, and the like. The storage medium is located in the memory 202, and the processor reads the information in the memory 202 and completes the steps of the method in combination with the hardware. The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Therefore, the above-mentioned embodiments of the present invention do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for generating a random network topology structure is characterized by comprising the following steps:

and determining one position as the access position of the equipment to be accessed in the three alternative access positions according to the average shortest path length of the three alternative access positions.

2. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

3. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

judging whether the first alternative access position is available;

4. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

determining whether the third alternative access location is available;

5. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

6. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

7. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

8. The method of claim 1, wherein said determining one of the three alternative access locations as the access location of the device to be accessed comprises:

9. An irregular network topology generation apparatus, comprising:

and the access position determining module is used for determining one position as the access position of the equipment to be accessed in the three alternative access positions according to the average shortest path length of the three alternative access positions.

10. The apparatus of claim 9, wherein the access location determining module comprises:

11. The apparatus of claim 9, wherein the access location determining module comprises:

12. The apparatus of claim 9, wherein the access location determining module comprises:

13. The apparatus of claim 9, wherein the access location determining module comprises:

14. The apparatus of claim 9, wherein the access location determining module comprises:

15. The apparatus of claim 9, wherein the access location determining module comprises:

16. The apparatus of claim 9, wherein the access location determining module comprises:

17. An irregular network topology generation apparatus, comprising:

at least one processor and a memory coupled with the at least one processor; wherein,

the at least one processor is configured to:

18. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

19. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

judging whether the first alternative access position is available;

20. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

determining whether the third alternative access location is available;

21. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

22. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

23. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to:

24. The apparatus of claim 17, wherein the at least one processor configured to determine one of the three alternative access locations as the access location for the device to be accessed is further configured to: