CN107222283B - WDM-FSO network node resource sharing method and system - Google Patents

WDM-FSO network node resource sharing method and system Download PDF

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CN107222283B
CN107222283B CN201710233760.0A CN201710233760A CN107222283B CN 107222283 B CN107222283 B CN 107222283B CN 201710233760 A CN201710233760 A CN 201710233760A CN 107222283 B CN107222283 B CN 107222283B
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node
wdm
cluster head
network
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CN107222283A (en
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张佳玮
纪越峰
张晶
李慧
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Beijing University of Posts and Telecommunications
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Beijing University of Posts and Telecommunications
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0254—Optical medium access
    • H04J14/0267—Optical signaling or routing

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  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

The present invention provides WDM-FSO network node resource sharing method and system, the method combination wavelength-division multiplex technique comprehensively consider the indexs such as link reliability, business load, proposes a kind of node resource sharing policy based on mobile WDM-FSO network.Scheme of the present invention is using the mobility of network node as a power for promoting network performance to be promoted, by between the mobile realization node of network node resource it is shared, influence of the change in topology to existing business caused by node motion is reduced, while reducing the blocking rate of business.

Description

WDM-FSO network node resource sharing method and system
Technical Field
The invention relates to the technical field of optical communication, in particular to a WDM-FSO network node resource sharing method and a WDM-FSO network node resource sharing system.
Background
At present, with the development of mobile communication, a wireless network embodies the characteristics of density and universality, so that a more flexible networking mode is required. Free Space Optics (FSO) technology is a high bandwidth wireless communication technology that uses laser as a transmission means. The FSO technique can provide high-speed and high-quality service in the fastest time by simply laying out antennas, without laying optical fibers. The WDM-FSO network can not only utilize the unique flexibility characteristics of the FSO technology, but also combine with WDM (Wavelength Division Multiplexing) technology to meet the networking requirements of large bandwidth and multiple services, and although attention is paid to space optical communication in recent years, research on the space optical communication is mainly focused on channel analysis and link performance improvement, research on the network is relatively less, and the construction of a flexible and reconfigurable mobile FSO network is a problem to be solved urgently.
The FSO network has the inherent characteristics of flexibility and mobility, wherein the flexibility means that a link can be quickly built or dismantled, and the mobility means that nodes in the FSO network are usually moving objects such as unmanned planes, automobiles and the like. The direct influence generated by the movement of the network node is that the topology changes, and the topology changes include the change of link distance, the change of the adjacent state of the network node (for example, some nodes can newly add neighbor nodes or the link with the original neighbor nodes is interrupted), and the change of link quality (for example, the link reliability and the interruption probability). The topology change may affect the traffic transmission in the network, for example, some link interruptions may cause all traffic passing through the link to be lost.
Wavelength division multiplexing FSO networks are networks with a high degree of flexibility and traffic carrying capability based on optical wavelength routing in combination with WDM technology in FSO networks. The wavelength division multiplexing optical network not only has the characteristic of large capacity of a WDM network, but also has the characteristic of flexibility of FSO, and meanwhile, the network capacity is greatly improved due to the combination of a wavelength routing technology. Key issues in WDM-FSO networks are routing and wavelength allocation. Routing and wavelength allocation need to satisfy two basic constraints, and different optical channels on the same laser link must have different wavelengths so as to avoid mutual interference between the channels; in networks with no or limited wavelength conversion capability, the optical path must use the same wavelength, i.e. wavelength continuity constraints, in all the optical fiber links it passes through. Routing and Wavelength Assignment (RWA) refers to finding routes from a source node to a destination node in an optical network and assigning corresponding wavelengths to the routes, given a set of lightpath connection requests, so that the purpose of routing and wavelength assignment is to establish a required lightpath for user traffic. The RWA problem in WDM-FSO networks is more complex: 1. node degree constraint: each node in the FSO network is provided with an optical lens, and the direction of transmitting and receiving signals by the node is determined by the lens, so that the FSO network node has to meet degree constraint conditions different from the traditional WDM network; 2. and (3) link reliability: because the FSO link is exposed in the atmosphere, the link performance is easily influenced by environmental factors such as rain, fog, snow, atmospheric turbulence and the like, the link performance must be considered when routing; 3. dynamic topology: the FSO network has the characteristic of dynamic property, the nodes can be moving vehicles, unmanned planes and the like, and the network topology is possibly changed at any time due to the movement of the nodes.
In the FSO network, nodes in the network are divided into clusters (clusters), some of the nodes are Cluster Head nodes (CH), other nodes are user nodes, and communication between users must be performed through the Cluster Head nodes. The user node has only one pair of transceivers (shots), and the cluster head node has a plurality of transceivers (shots). Due to limited network resources, in order to improve network survivability, a 'help' strategy can be performed among nodes, that is, if the energy (electric quantity) of one node is about to be exhausted, the node with the largest residual energy in the neighbor nodes can be moved to the current node, the energy of the node is shared with the current node, and access is provided for some user nodes. This scheme can be regarded as a resource sharing scheme, but the current research only considers the residual energy of the nodes, and does not consider the influence of the node movement on the network service. Obviously, as shown in fig. 1, the fundamental problem with the movement of the nodes is the change in topology: 1. changes in link performance, such as link physical distance, outage probability, etc.; 2. the change of node neighbor nodes, for example, the original links of some nodes may be interrupted, and some nodes will have new neighbor nodes; this change will affect the traffic in the current network and the routing of local nodes; meanwhile, the network can support very limited traffic in the current research, and when the traffic is more or the traffic burstiness is higher, serious resource competition and traffic blocking must be generated; in summary, the "help" scheme, which only considers the residual energy of the nodes, is obviously not suitable for the actual network scenario.
Disclosure of Invention
To overcome the above problems or to at least partially solve the above problems, the present invention provides a node resource sharing method and system.
According to an aspect of the present invention, there is provided a node resource sharing method, including:
step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request;
step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position;
step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network;
and 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path.
Further, step 4 is followed by:
and 5, confirming that the wavelength is successfully distributed, and taking the shortest path between the moved weight minimum node and a cluster head node accessed by a target node corresponding to the service request as a light path of the service request.
Further, step 4 is followed by:
and 5', confirming that the wavelength allocation fails, and moving the node with the small weight value nth in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position, wherein n is the number of current circulation.
Further, the step 2 further comprises:
s21, establishing a physical topology of the WDM-FSO network, and calculating the weight value of each node in the topology based on the service load and the interruption probability of the adjacent link;
and S22, moving the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node to the optimal position.
Further, the step 4 further comprises:
and obtaining a path set between the two nodes by utilizing a KSP algorithm based on the shortest path between the moved weight minimum node and the cluster head node accessed by the destination node corresponding to the service request, and allocating wavelength for the shortest path in the path set.
Further, the degree of the cluster head node in the WDM-FSO network for accessing the user does not exceed a first threshold value; the degree of cluster head nodes in the WDM-FSO network used for inter-cluster-head communication does not exceed a second threshold.
Further, the S22 further includes:
the used degree of the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should be smaller than the threshold value of the degree of the cluster head node accessed by the source node for accessing the user.
Further, the step of calculating the weight value of each node in the topology based on the traffic load and the outage probability of the adjacent link in S21 further includes:
ρij＝wij/Cij
α+β＝1
where ρ isijRepresenting the traffic occupancy, p, on the link (i, j)ijDenotes the normalized outage probability, C, of the link (i, j)ijRepresenting the total number of wavelengths, w, per link in the networkijRepresents the number of wavelength occupancies on link (i, j); NWiIs the weight value of the ith node, MiThe neighbor node of the node i, α is the weight of the traffic occupancy, β is the weight of the outage probability.
Further, the optimal position in S22 is obtained by:
the definition p is the reliability of the movement,the p value represents the outage probability distribution of the neighboring links of node i as the average outage probability of the neighboring links of node i:
let p be the mobility reliability of the node i before moving, and p' be the mobility reliability of the node after moving, and the moving process should satisfy:
p′≤p
and based on the optimization target and the constraint condition, obtaining the optimal position to which the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should move.
According to an aspect of the present invention, there is provided a WDM-FSO network node resource sharing system comprising:
the confirming module is used for confirming that the cluster head node accessed by the source node corresponding to the service request has no available wavelength;
a moving module, configured to move a node with a smallest weight among all neighbor nodes of a cluster head node accessed by the source node in a physical topology of the WDM-FSO network to an optimal position;
an establishing module, configured to establish a potential link of the moved node with the smallest weight and update a physical topology of the WDM-FSO network;
and the distribution module is used for finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the updated physical topology of the WDM-FSO network and carrying out wavelength distribution on the shortest path.
The method combines a wavelength division multiplexing technology, comprehensively considers indexes such as link reliability, service load and the like, and provides a node resource sharing strategy based on the mobile WDM-FSO network. The scheme of the invention takes the mobility of the network node as a driving force for promoting the network performance to be improved, realizes the resource sharing among the nodes through the movement of the network node, reduces the influence of the topology change caused by the movement of the node on the existing service, and simultaneously reduces the blocking rate of the service.
Drawings
FIG. 1 is a schematic diagram of a topology change caused by node movement in a prior FSO network;
fig. 2 (a) is a schematic diagram of traffic congestion caused by node movement in a conventional WDM network, and (b) is a schematic diagram of traffic congestion caused by node movement in an existing FSO network;
FIG. 3 is a schematic overall flow chart of a WDM-FSO network node resource sharing method according to an embodiment of the invention;
fig. 4 is a schematic diagram of a node moving range in a WDM-FSO network node resource sharing method according to an embodiment of the present invention.
Fig. 5 (a) shows a topology before node movement in the WDM-FSO network node resource sharing method according to the embodiment of the present invention, and (b) shows a topology after node movement in the WDM-FSO network node resource sharing method according to the embodiment of the present invention;
FIG. 6 is a flow chart illustrating a WDM-FSO network node resource sharing method according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of an overall framework of a WDM-FSO network node resource sharing system according to an embodiment of the invention;
fig. 8 is a schematic device diagram of a WDM-FSO network node resource sharing method according to an embodiment of the present invention.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
For WDM-FSO networks, whether wavelength resources are sufficient is one of the keys to determine the network traffic carrying capacity. Meanwhile, since the node movement may affect the link quality, the link quality is also another key factor for measuring the network performance. Therefore, the invention sets out a resource sharing scheme based on node movement based on the help strategy and taking the wavelength and the link quality as reference. As shown in fig. 2, the FSO network can cope with the traffic blocking situation with node movement compared to the conventional WDM network. As shown in fig. 2 (a), after the service request arrives, the cluster heads connected to the user node, that is, the adjacent link wavelengths of the node 2 are all occupied, but since the node in the network is movable, the node 3 may be selected to move to the node 2, and the user node is allowed to access the node 3, thereby routing and allocating the wavelengths for the service again; as shown in (b) of fig. 2, after the service request arrives, the wavelength resource of the base station accessed by the user is exhausted, and since the optical fiber network is fixed, a new link cannot be established for the service, the service request must be blocked; in summary, the present invention aims to design a node resource sharing policy for a mobile FSO network, formulate an alternative node selection criterion that simultaneously considers the wavelength usage and the link performance, and design an algorithm for the node to move the optimal location, and perform routing and wavelength allocation based on the criterion.
Fig. 3 is a schematic flowchart illustrating an overall resource sharing method for WDM-FSO network nodes according to an embodiment of the present invention. In general, the method comprises the following steps:
step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request;
step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position;
step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network;
and 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path.
The invention discloses a WDM-FSO network node resource sharing method, which solves the technical problem that: in a mobile FSO network, due to limited network resources (wavelength and energy), the resource consumption of a cluster head node in the network causes that all users accessing the cluster head face the problem of no available resource, and when a service request arrives, if a cluster head node accessed by a source node (user) has no available resource, a neighbor node needs to move to a current node to share its device and wavelength resources, so as to provide access for the user. The movement of this node causes a change in the network topology: 1. changes in link performance, such as physical distance, outage probability, etc.; 2. the change of node neighbor nodes, for example, the original links of some nodes may be interrupted, and some nodes will have new neighbor nodes; these topology changes all affect the transmission and routing of services, so the existing services and link quality should be considered when selecting mobile nodes, the purpose of the node mobility policy and routing algorithm is to minimize the impact on the existing services, and to select a route for a new service based on the moved topology.
In another embodiment of the present invention, a method for sharing resources of a WDM-FSO network node further includes, after step 4:
and 5, confirming that the wavelength is successfully distributed, and taking the shortest path between the moved weight minimum node and a cluster head node accessed by a target node corresponding to the service request as a light path of the service request.
In another embodiment of the present invention, a method for sharing resources of a WDM-FSO network node further includes, after step 4:
and 5', confirming that the wavelength allocation fails, and moving the node with the small weight value nth in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position, wherein n is the number of current circulation.
In another embodiment of the present invention, a method for WDM-FSO network node resource sharing, said step 2 further comprises:
s21, establishing a physical topology of the WDM-FSO network, and calculating the weight value of each node in the topology based on the service load and the interruption probability of the adjacent link;
and S22, moving the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node to the optimal position.
In another embodiment of the present invention, a method for WDM-FSO network node resource sharing, step 4 further includes:
and obtaining a path set between the two nodes by utilizing a KSP algorithm based on the shortest path between the moved weight minimum node and the cluster head node accessed by the destination node corresponding to the service request, and allocating wavelength for the shortest path in the path set.
In another embodiment of the invention, a method for sharing node resources of a WDM-FSO network, wherein the degree of a cluster head node for accessing a user in the WDM-FSO network does not exceed a first threshold value; the degree of cluster head nodes in the WDM-FSO network used for inter-cluster-head communication does not exceed a second threshold.
In another embodiment of the present invention, a method for sharing resources of a WDM-FSO network node, the S22 further includes:
the used degree of the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should be smaller than the threshold value of the degree of the cluster head node accessed by the source node for accessing the user.
In another embodiment of the present invention, in a method for sharing resources of a WDM-FSO network node, the step of calculating a weight value of each node in the topology based on traffic load and outage probability of adjacent links in S21 further includes:
ρij＝wij/Cij
α+β＝1
where ρ isijRepresenting the traffic occupancy, p, on the link (i, j)ijDenotes the normalized outage probability, C, of the link (i, j)ijRepresenting the total number of wavelengths, w, per link in the networkijRepresents the number of wavelength occupancies on link (i, j); NWiIs the weight value of the ith node, MiThe neighbor node of the node i, α is the weight of the traffic occupancy, β is the weight of the outage probability.
In another embodiment of the present invention, in a method for resource sharing of a WDM-FSO network node, the optimal position in S22 is obtained by:
the definition p is the reliability of the movement,the p value represents the outage probability distribution of the neighboring links of node i as the average outage probability of the neighboring links of node i:
let p be the mobility reliability of the node i before moving, and p' be the mobility reliability of the node after moving, and the moving process should satisfy:
p′≤p
and based on the optimization target and the constraint condition, obtaining the optimal position to which the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should move.
In another embodiment of the present invention, a method for resource sharing of nodes of a WDM-FSO network is further described below with reference to the following embodiment.
First, the network model designed in this embodiment is as follows:
describing the physical topology of the network using a simple graph G (V, E), where V is the set of all nodes in the network and E is the set of all links in the network; vc belongs to V and represents all CH nodes in the network, and Vu belongs to V and represents all user nodes in the network; ec belongs to E and represents all links between CH in the network, and Eu belongs to E and represents the links between all CH in the network and users; cijRepresenting the total number of wavelengths, w, per link in the networkijRepresenting the number of wavelength occupancies (number of incumbent traffic) on the link (i, j), pijRepresenting the traffic occupancy, p, on the link (i, j)ijRepresenting the probability of interruption after normalization of the link (i, j), i.e. the reception of the signal P at the receiving endR≤PthProbability of (P)thAs threshold value of received power, PthFor the link outage probability threshold, the outage probability of all links in the move cannot exceed this threshold.
Since FSO communication is performed through a high-performance telescope, the number of lenses on each node is limited in the node model of the present invention, and therefore, the number of lenses needs to be limited. Assuming degree d of cluster head node for accessing useraDegree d not exceeding K1 for inter-cluster communicationcNot exceeding K2.
If node i has MiA neighbor node, the neighbor node set of node i is Ni＝{Ni(1),Ni(2),…,Ni(Mi) }, define node weights NWiAs mobile node selection criteria, one can see the NWiAnd simultaneously, the service load of the node and the interruption probability of the adjacent link are considered.
ρij＝wij/Cij (1)
α+β＝1 (3)
da(j)<K1 (4)
And selecting the neighbor node with the minimum NW as the candidate mobile node according to the criteria of the formulas (1) to (4), and simultaneously ensuring that the used degree of the node is less than K1.
To avoid the continuous degradation and even interruption of some links with poor performance in local topology caused by node movement, p is defined as the reliability of movement,representing the interrupt probability distribution of the adjacent link of the node i for the average interrupt probability of the adjacent link of the node i by the value p;
let p be the mobility reliability of the node i before movement and p' be the mobility reliability of the node after movement, and the movement process should satisfy
p′≤p (7)
(6) According to the scheme, if V1 requires V3 to share wavelength resources, the scattering angle of V1 is α, the distance between V1 and V3 is r, and the movement of V3 should be limited in the sector shown in FIG. 4, according to the above optimization targets and constraints, the optimal position after V3 movement can be obtained and is marked as loc (x, y), and the movement of V3 to the position is immediately terminated.
|E1(j) L represents the number of all adjacent links of the node j, (8) the original links of the node j are not reduced in the moving process, which is also the premise of moving strategies.
The algorithm function of the present invention is described as follows:
for the service request f (s, d), the source node is s (user node), and the cluster head node accessed by the source node is scThe destination node is d (user node), and the cluster head accessed by the destination node is dc. It can be seen that the source node and the destination node are both user nodes and have no routing function, and when routing and wavelength are performed for the service, only the source cluster head s needs to be consideredcAnd destination cluster head dc. And the transceiver/shot of each cluster head is limited, and the degree constraint of the node needs to be considered. When the service request f (s, d) arrives, the cluster head s accessed by the source node s needs to be judgedcIf there is available wavelength resource, if scAnd if no available wavelength resource exists, carrying out a mobile resource sharing strategy to provide access for the s and carry the service of the s. The mobile resource sharing and routing strategy mainly comprises the following steps:
1. and establishing a virtual topology. Establishing a virtual topology G ' (V ', E ') according to the physical topology G (V, E), wherein V ' ← Vc, E ' ← Ec.
2. A mobile neighbor node is selected. Record SCAll neighbouring nodes Vi(only at S)CThe cluster head node in the communication range is SCNeighbor node), the node V with the smallest node weight NW is selectediMove to loc (x, y) with the moving process at ViAnd terminates immediately upon reaching loc (x, y).
3. And establishing a potential link and updating the topology. ViAfter the moving process, some nodes may enter ViAnd therefore requires potential links to be established on the physical topology.
4. And establishing a light path for the service. V after movingiIs denoted by sc(new) is sc(new) and dcThe KSP algorithm is executed and the calculated paths are wavelength-allocated.
Referring to fig. 6, in another embodiment of the present invention, an embodiment of a method for WDM-FSO network node resource sharing is shown, which includes the following steps:
(1) according to the graph G (V, E), establishing a virtual topology G ' (V ', E '), and calculating a node weight NWiAccording to the NW, the nodes are recorded in a list L in an ascending order;
(2) selecting NW minimum node ViIn virtual topology to scMovement, terminating the movement when moved to the optimal position loc (x, y);
(3) for ViAll nodes V within communication rangejEstablishing a potential link, the condition for establishing the potential link being dc(Vi)<K2, and ViAnd VjThere is no link between them, the topology is updated and marked as G';
(4) v after movingjIs denoted by sc(new) is sc(new) and dcExecuting the KSP algorithm, and recording the obtained path set as p (f) ═ p1,p2，…,pk}
(5) Allocating wavelength for shortest path in p (f);
(6) if the wavelength allocation is successful, deleting the path from P (f), wherein the path is the optical path of the service f (s, d), and ending the algorithm; if not, continuing to execute the step (5) on the secondary short path until
(7) If it is notAnd (5) selecting the next node in the list L and executing the steps (1) to (6).
In fig. 7, a schematic diagram of an overall framework of a WDM-FSO network node resource sharing system in one embodiment is shown. In its entirety, comprising:
a confirming module a1, configured to confirm that there is no available wavelength in a cluster head node accessed by a source node corresponding to a service request;
a moving module A2, configured to move a node with the smallest weight among all neighboring nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to an optimal position;
a building module a3, configured to build a potential link of the moved weighted minimum node and update a physical topology of the WDM-FSO network;
an allocating module a4, configured to find a shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and perform wavelength allocation on the shortest path.
In another embodiment of the present invention, a WDM-FSO network node resource sharing system, the allocation module is further configured to: and confirming that the wavelength is successfully distributed, wherein the shortest path between the moved weight minimum node and a cluster head node accessed by a target node corresponding to the service request is used as the light path of the service request.
In another embodiment of the present invention, a WDM-FSO network node resource sharing system, the mobility module is further configured to: and confirming that the wavelength allocation fails, and moving the node with the small weight value nth in all the neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position, wherein n is the number of current cycles.
In another embodiment of the present invention, a WDM-FSO network node resource sharing system, the mobility module is further configured to:
s21, establishing a physical topology of the WDM-FSO network, and calculating the weight value of each node in the topology based on the service load and the interruption probability of the adjacent link;
and S22, moving the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node to the optimal position.
In another specific embodiment of the present invention, the allocating module is further configured to obtain a path set between the two nodes by using a KSP algorithm, and allocate a wavelength to the shortest path in the path set, where the shortest path is between the moved node with the minimum weight and a cluster head node accessed by a destination node corresponding to the service request.
In another embodiment of the invention, a node resource sharing system of a WDM-FSO network, wherein the degree of a cluster head node for accessing a user in the WDM-FSO network does not exceed a first threshold; the degree of cluster head nodes in the WDM-FSO network used for inter-cluster-head communication does not exceed a second threshold.
In another embodiment of the present invention, in a WDM-FSO network node resource sharing system, the mobility module is further configured to use the used degree of the node with the smallest weight among all the neighbor nodes of the cluster head node accessed by the source node, which should be smaller than a threshold of the degree of the cluster head node accessed by the source node for accessing the user.
In another embodiment of the present invention, a WDM-FSO network node resource sharing system, the mobility module is further configured to:
ρij＝wij/Cij
α+β＝1
where ρ isijRepresenting the traffic occupancy, p, on the link (i, j)ijDenotes the normalized outage probability, C, of the link (i, j)ijRepresenting the total number of wavelengths, w, per link in the networkijRepresents the number of wavelength occupancies on link (i, j); NWiIs the weight value of the ith node, MiThe neighbor node of the node i, α is the weight of the traffic occupancy, β is the weight of the outage probability.
In another embodiment of the present invention, a WDM-FSO network node resource sharing system, the optimal location is obtained by:
the definition p is the reliability of the movement,the p value represents the outage probability distribution of the neighboring links of node i as the average outage probability of the neighboring links of node i:
let p be the mobility reliability of the node i before moving, and p' be the mobility reliability of the node after moving, and the moving process should satisfy:
p′≤p
and based on the optimization target and the constraint condition, obtaining the optimal position to which the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should move.
Fig. 8 is a block diagram showing the structure of an apparatus of the WDM-FSO network node resource sharing method according to the embodiment of the present application.
Referring to fig. 8, the test equipment of the WDM-FSO network node resource sharing method includes: a processor (processor)801, a memory (memory)802, a communication Interface (Communications Interface)803, and a bus 804;
wherein,
the processor 801, the memory 802 and the communication interface 803 complete mutual communication through the bus 804;
the communication interface 803 is used for information transmission between the test equipment and the communication equipment of the WDM-FSO network node resource sharing method;
the processor 801 is configured to call program instructions in the memory 802 to perform the methods provided by the above-described method embodiments, including for example: step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request; step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position; step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network; and 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path.
The present embodiment discloses a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the method provided by the above-mentioned method embodiments, for example, comprising: step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request; step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position; step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network; and 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path.
The present embodiments provide a non-transitory computer-readable storage medium storing computer instructions that cause the computer to perform the methods provided by the above method embodiments, for example, including: step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request; step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position; step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network; and 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path.
Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
The embodiments of the device and the like of the WDM-FSO network node resource sharing method described above are merely illustrative, where the units illustrated as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, may be located in one place, or may also be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, the method of the present application is only a preferred embodiment and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

  1. A WDM-FSO network node resource sharing method, comprising:
    step 1, confirming that no available wavelength exists in a cluster head node accessed by a source node corresponding to a service request;
    step 2, moving the node with the minimum weight in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position;
    step 3, establishing the potential link of the moved node with the minimum weight and updating the physical topology of the WDM-FSO network;
    step 4, finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength allocation on the shortest path;
    the step 2 further comprises:
    s21, establishing a physical topology of the WDM-FSO network, and calculating the weight value of each node in the topology based on the service load and the interruption probability of the adjacent link;
    s22, moving the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node to the optimal position;
    the optimal position in S22 is obtained by:
    the definition p is the reliability of the movement,is the average outage probability of the neighboring links of node i, and p represents the outage probability distribution of the neighboring links of node i, pijDenotes the normalized outage probability, M, of the link (i, j)iNeighbor node to node i:
    let p be the mobility reliability of the node i before moving, and p' be the mobility reliability of the node after moving, and the moving process should satisfy:
    p'≤p
    based on an optimization target and a constraint condition, obtaining an optimal position to which a node with the minimum weight in all neighbor nodes of a cluster head node accessed by the source node should move; whereinIs a nodei average outage probability of neighboring links.
  2. 2. The method of claim 1, wherein step 4 is further followed by:
    and 5, confirming that the wavelength is successfully distributed, and taking the shortest path between the moved weight minimum node and a cluster head node accessed by a target node corresponding to the service request as a light path of the service request.
  3. 3. The method of claim 1, wherein step 4 is further followed by:
    and 5', confirming that the wavelength allocation fails, and moving the node with the small weight value nth in all neighbor nodes of the cluster head node accessed by the source node in the physical topology of the WDM-FSO network to the optimal position, wherein n is the number of current circulation.
  4. 4. The method of claim 1, wherein step 4 further comprises:
    and based on the moved weight minimum node and the cluster head node accessed by the destination node corresponding to the service request, obtaining a path set between the two nodes by using a KSP algorithm, and allocating wavelength for the shortest path in the path set.
  5. 5. The method of claim 1, wherein a degree of a cluster head node in the WDM-FSO network to access a user does not exceed a first threshold; the degree of cluster head nodes in the WDM-FSO network used for inter-cluster-head communication does not exceed a second threshold.
  6. 6. The method according to claim 4, wherein said S22 further comprises:
    the used degree of the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node should be smaller than the threshold value of the degree of the cluster head node accessed by the source node for accessing the user.
  7. 7. The method of claim 4, wherein the step of calculating the weight value of each node in the topology based on the traffic load and the outage probability of the adjacent link in S21 further comprises:
    ρij＝wij/Cij
    α+β＝1
    where ρ isijRepresenting the traffic occupancy, p, on the link (i, j)ijDenotes the normalized outage probability, C, of the link (i, j)ijRepresenting the total number of wavelengths, w, per link in the networkijRepresents the number of wavelength occupancies on link (i, j); NWiIs the weight value of the ith node, MiThe neighbor node of the node i is α weight of the traffic occupancy rate and β weight of the outage probability.
  8. 8. A WDM-FSO network node resource sharing system, comprising:
    the confirming module is used for confirming that the cluster head node accessed by the source node corresponding to the service request has no available wavelength;
    a moving module, configured to move a node with a smallest weight among all neighbor nodes of a cluster head node accessed by the source node in a physical topology of the WDM-FSO network to an optimal position;
    an establishing module, configured to establish a potential link of the moved node with the smallest weight and update a physical topology of the WDM-FSO network;
    the distribution module is used for finding the shortest path between the moved weight minimum node and a cluster head node accessed by a destination node corresponding to the service request in the physical topology of the updated WDM-FSO network, and performing wavelength distribution on the shortest path;
    the mobile module is further configured to:
    s21, establishing a physical topology of the WDM-FSO network, and calculating the weight value of each node in the topology based on the service load and the interruption probability of the adjacent link;
    s22, moving the node with the minimum weight in all the neighbor nodes of the cluster head node accessed by the source node to the optimal position;
    the optimal position is obtained by the following steps:
    the definition p is the reliability of the movement,is the average outage probability of the neighboring links of node i, and p represents the outage probability distribution of the neighboring links of node i, pijDenotes the normalized outage probability, M, of the link (i, j)iNeighbor node to node i:
    let p be the mobility reliability of the node i before moving, and p' be the mobility reliability of the node after moving, and the moving process should satisfy:
    p'≤p
    based on an optimization target and a constraint condition, obtaining an optimal position to which a node with the minimum weight in all neighbor nodes of a cluster head node accessed by the source node should move; whereinIs the average outage probability of the neighboring links of node i.
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