CN101547381A - Multicast RWA method with signal power attenuation limit in all-optical network - Google Patents
Multicast RWA method with signal power attenuation limit in all-optical network Download PDFInfo
- Publication number
- CN101547381A CN101547381A CN200910083901A CN200910083901A CN101547381A CN 101547381 A CN101547381 A CN 101547381A CN 200910083901 A CN200910083901 A CN 200910083901A CN 200910083901 A CN200910083901 A CN 200910083901A CN 101547381 A CN101547381 A CN 101547381A
- Authority
- CN
- China
- Prior art keywords
- link
- node
- power
- multicast
- multicast tree
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Small-Scale Networks (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
The invention provides a multicast RWA method with signal power attenuation limit in an all-optical network, which is applied to the ranges of an all-optical metropolitan area network and other medium-scale all-optical networks. The method solves the problems of route selection and wavelength distribution in the all-optical network. The method comprises the following steps: updating a logical topology on each wavelength of the network in real time by a node; when a multicast request reaches, selecting the logical topology of one wavelength according to a determined sequence to establish a multicast tree; preferentially adding the node close to a source node as the basic principle of establishing the multicast tree; and for a destination node which cannot be added into the multicast tree, exchanging the wavelength to establish another multicast tree. The method has the main characteristics that temporary power and minimum power limits of a signal on each edge link are considered when the multicast tree is established, and only the link of which power is more than the power limit can be added into the multicast tree. Therefore, the method ensures that the signal power reaching the destination node meets the lowest power requirement, and reduces error rate.
Description
Technical field
The invention belongs to the multicast Route Selection in all optical network and the technical field of Wavelength Assignment, being particularly useful for network size is not to connect denser all-optical network between too big and the node, as full light metropolitan area network etc.
Background technology
Multicasting technology in the optical-fiber network generally is conceived to minimize the cost of cast communication: cast communication will be sought a multicast forest that can connect source node and all destination nodes and (in particular cases have only one tree in the multicast forest in whole network, Fig. 2 provides an example), this multicast forest is made up of a lot of bar links, use every link all can produce certain cost, then the cost sum of link is exactly the cost of cast communication, and designer's purpose is to make this cost minimum.This problem is a Sterner minimum tree (SMT, a Steiner Minimum Tree) problem.
In actual applications, except the cost of cast communication, also having a lot, other problem needs to consider.In the ordinary course of things, always ignore nonlinear effect, think that the various performances of light signal all are linear.But, when optical signal power arrives to a certain degree greatly, increase because the chromatic dispersion of light and the caused signal attenuation of other nonlinear effect meeting are exponential series.This has just limited the peak power that source node sends signal.On the other hand, destination node wants the signal demodulation correctly that receives, and the power of this signal just can not be too low, and the power when promptly signal arrives destination node can not be too little.The factor of this two aspect just requires the decay of signal in transmission course can not be too big, that is also will consider the maximum attenuation of signal when setting up multicast tree.
In existing technology, has only seldom a part of signal power decay in the multicast of having considered.Du and Hu have talked out Steiner k-tree routing issue in their works Steiner Tree problem in Computer Communication Networks: for given source node and destination node set, make up the multicast forest of a minimum cost, comprise k destination node at most in feasible every tree wherein.Each node that this problem can be regarded as in optical-fiber network at network all is equipped with the adjustable optical splitter of splitting ratio, and the signal that requires source node to send is decayed into original 1/k at the most when arriving destination node.But since the adjustable optical splitter of splitting ratio relatively costliness and technology also be not very ripe, this method has very big difficulty when realizing.
People such as Wu have introduced a kind of minimum approximation method of peak signal decay that makes source node arrive each destination node in its paper Multicast routing with power consideration in sparse splitting WDMnetworks.But, when communicating,, and do not need decay minimum as long as the signal that receives is enough by force.This method is placed on main energy and minimizes on the maximum attenuation, and some has been attended trifles and neglect essentials.
Summary of the invention
The purpose of this invention is to provide a kind of interior multicast RWA (RWA, Routingand Wavelength Assignment) method of all optical network with signal power decay restriction.Because the network size of metropolitan area network is less relatively and node between connection dense relatively, so we do not use signal amplifier and wavelength shifter at hypothesis in network when carrying out the network planning, promptly Guan Jian optics has only optical splitter.Because the fixing optical splitter of beam split rate is divided into several parts of outputs with signal constant power ground, signal attenuation is very big, so need consider the restriction of signal power when carrying out the multicast Route Selection.
For overcoming the above problems, the present invention proposes a kind of interior multicast RWA method of all optical network with signal power decay restriction.The method is considered signal power and minimum power limits on the link according to the restriction of destination node to minimum received signal power when carrying out Route Selection and Wavelength Assignment.Concrete steps are as follows:
(1) from the wavelength available set, selects a wavelength,, on the logical network topology of this wavelength, embark a multicast tree from source node.
(2) added multicast tree and link itself does not add multicast tree when the top of a link, claimed that then this link is the edge link; To be divided three classes from the edge link that source node sends: active link, dormancy link, dead link; Active link is that top is source node or for non-source node with multicast-capable or for adding the non-source node of multicast tree and loose no multicast-capable, and terminal is the edge link of the node that do not add multicast tree; The dormancy link is that top is source node or for non-source node with multicast-capable or for adding the non-source node of multicast tree and loose no multicast-capable, terminal is for having added the edge link of multicast tree and loose node; Remaining edge link is dead link, and these links satisfy in following two conditions at least: top is for fixing non-source node, and perhaps terminal is fixing arbitrary node.
(3) distribute an interim power P ower (e) and an interim lower limit power P owConst (e) for every active link e.
(4) specify a label for each bar active link, numerical value that label is marked equals that (u, the distance D ist (u) of top v) on multicast tree add it self cost Cost (e), i.e. Label (e)=Dist (u)+Cost (e) to link e=by source node.
(5) from active link set, choose a link of label value minimum, be in a manner of speaking e=(u, v).Judge whether inequality Power (e) 〉=PowConst (e) sets up.If set up, (u v) adds multicast tree, and the edge link that sends from v is classified according to the described method of step 2.If be false, with (u v) deletes from the active link set, reselects the link of label value minimum.
(6) when a destination node adds multicast tree, node and link on will the path from source node to this destination node be fixed on the multicast tree, other branches that will send from the node of the no multicast-capable on this paths are deleted from multicast tree, and the set of three types of edge link is upgraded according to principle described in the step 2;
(7) when there not being the active link optional time, leave out the link that does not arrive destination node in the current multicast tree, choose a wavelength again the residue destination node is begun to make up a multicast tree from source node again.Repeat above process, when one of following two kinds of situations take place, stop: each destination node all in certain multicast tree, this moment resultant the set of multicast tree, or be referred to as the multicast forest, be institute and ask; Do not have wavelength optional, this moment, network blocked.
Can further, said method also has following characteristics: in described step (2), the edge link is divided into three kinds of set that have link of different nature, decides in following step according to the set at their places add the multicast tree that is making up.
Further, said method also has following characteristics: in described step (3), specify a temporary signal power lower limit for every active link, this interim power lower limit has guaranteed that the adding of this link can not destroy the signal power limitations of fixed link.
Further, said method also has following characteristics: in described step (3), specify an interim signal power for each bar active link, this link that relatively comes to determine by this temporary signal power and its temporary signal power lower limit is the adding multicast tree, still becomes dead link.
Further, said method also has following characteristics: in described step (4), add a label for every active link, decide their to add the priority that is making up multicast tree according to the value of label.
Further, said method also has following characteristics: in described step (6), when a destination node added multicast tree, the path from source node to this destination node just was fixed, and does not need to consider the pruning problem of this paths uplink in following step again.
Description of drawings
Fig. 1 is an example of logical network topology.Upper left figure is the physical topology of network, and what mark on the link is the wavelength available of this link; We can be with wavelength X
1, λ
2, λ
3On the expression of coming of logical network topology branch.As can be seen from the figure the logical topology on wavelength and the physical topology of network have certain difference.
Fig. 2 is the example of multicast forest.V1 is a source node among the figure, and v3, v4, v5, v6, v8 are the destination node of a multicast request.At λ
1And λ
2Make up two multicast tree on the logical network topology of two wavelength and finish current multicast request, these two multicast tree have been formed a multicast forest.
The example of Fig. 3 for the edge link is classified.Among the figure, heavy line is represented fixed link, and fine line representative does not add incoming link, and the representative of line segment dotted line adds but fixed link not, and pecked line is represented the Xin Jia incoming link; The heavy line circle is represented source node, and the shade circle is represented destination node, and broken circle is represented newly added node, and the fine line circle is represented other node.When link (v3, when v6) adding multicast tree, three links that send from its terminal have added different set respectively: because v5 is fixing, so (v6 v5) becomes dead link; V7 has added multicast tree, but also unfixing, so (v6 v7) adds dormancy link set L
FaintV9 does not also add multicast tree, so (v6 v9) adds active link set L
Active
Fig. 4 is a directed graph, and therefrom predecessor between the node and follow-up relation as can be seen, and predecessor between the link and follow-up relation: (1) v2 is the descendant node of v1 to v7, and having only v2, v3, v4 is its immediate successor; V1, v2, v3, v6 are the former nodes of v7, and having only v6 is its direct predecessor.(2) link (v2, v5), (v2, v6), (v6, v7) all be (v1, follow-up link v2) have only (v2, v5), (v2 v6) is its immediate successor; Link (v1, v2), (v1, v3), (v2, v6), (v3, v6) all be (v6, former link v7) have only (v2, v6), (v3 v6) is its direct predecessor.
Fig. 5 is an example that distributes temporary signal power to active link.Among the figure, zero expression MC node, represents the MI node; Heavy line is fixed link, and dotted line is for adding but loose link; Shaded boxes is a destination node.As can be seen from the figure MC node and MI link that node the sends difference when distributing interim power: u is a MC node, (u, v1) and (u, v2) fixing, (u, v3) and (u v4) is active link, and then their interim power is:
X is a MI node, (x, v6) and (x v7) is active link, and then their interim power is: Power (x, v6)=Power (w, x), Power (x, v7)=Power (w, x).
Fig. 6 is for to specify an example of interim Power Limitation to adding multicast tree link and active link.Among the figure, zero expression MC node, represents the MI node; Heavy line is fixed link, and dotted line is for adding but loose link; Shaded boxes is a destination node.(1) for the link that adds multicast tree: (v1, v3), (v4, v5) and (v4, fixedly immediate successor number v8) is 0, so be limited to 1 under their minimum power; (v2 v4) has two fixing immediate successors, and the interim Power Limitation of these two immediate successors is 1, thus PowConst (v2, v4)=2 * 1=2; (v1 v2) has a fixing immediate successor, and its interim Power Limitation is 2, thus PowConst (v1, v2)=1 * 2=2.(2) for active link: (v2, top v9) is a MC node, and the link that directly sends has one to be fixed, and the Power Limitation of this link is 2, thus PowConst (v2, v9)=2; (v3, v6), (v3, top v7) is the MI node, so their Power Limitation all is 1.Therefrom as can be seen, specifying under the interim power in limited time, the link that sends from stationary nodes and never stationary nodes send link and be very different.
Fig. 7 is the flow chart of method that the present invention gives.Can more clearly understand the implementation process of method by this figure.
Embodiment
The scope of application of the present invention is full light metropolitan area network and similar scale or more small-scale all-optical network, does not use signal amplifier and wavelength shifter in the network planning.Optical fiber is lower to the decay of signal at present, and for example G.654 the decay of model optical fiber only is 0.185dB/km, and along with the development of technology and the application of new material, this value also can continue to diminish.So in the network of metropolitan area network and following scale, the signal attenuation that produces owing to optical fiber from the source node to the destination node is just not too large.On the other hand since distance from source node to each destination node differ can be not a lot, the difference of signal attenuation can be very not big yet.Suppose that the average attenuation from source node to each destination node is A.For the purpose of the convenience of handling problems, the power attenuation A that we can directly send source node signal is so many, thereby does not consider the decay of optical fiber.The result who obtains so also is approximate being suitable in original model, and performance also with original model in very approaching.We also can change the signal attenuation of source node into maximum attenuation by average attenuation, and the multicast tree of gained necessarily is applicable to original network model like this, but cost may have certain increase.The emphasis difference of two kinds of methods can be accepted or rejected in actual applications as required to some extent, but identical a bit be the influence of having eliminated link attenuation.So do not consider the decay that causes by optical fiber in the present invention.If restricting signal is decayed into original 1/P at most when arriving destination node, then in the method, we can suppose that the power that source node sends signal is P, and the signal power that the restriction destination node is received is at least 1, gained problem and former problem equivalent.
Usually we (V, E c) represent an optical-fiber network with a weighting connected graph G.Wherein V is the set of optical node, and E is the set of optical fiber link, and c:E → R is to use the cost of every link.In topology of networks, if having the limit to link to each other between two optical nodes, this edge is represented two parallel links, and the communication of both direction is provided respectively, and the performance of communication is identical with cost.In multicast request, represent source node with s, represent the set of multicast destination node with D.The method will make up a multicast forest F, and (s D) makes and can arrive all destination nodes from source node, and makes the cost of cast communication as far as possible little under given signal power decay restriction.Every link e=(u, expense v) be designated as Cost (e) or Cost (u, v).Use D at the structure of multicast forest therebetween,
NotStorage does not temporarily also add the set of the destination node of multicast forest.We always select for use a wavelength (according to the operating position of this wavelength on each bar link by certain rule at every turn, corresponding logical network topology), on the logical network topology structure of this wavelength, set up a multicast tree that arrives a part (perhaps whole) destination node.
In the building process of this multicast tree, we will use several memories to write down several variablees.Use V
InRecord adds the set of the node of current multicast tree, and these nodes also might be deleted from multicast tree in the step of back.Use V
FixedRecord has been fixed on the set of the node in the multicast tree, and these nodes can be not deleted.Obviously at any one moment V
FixedAll be V
InA subclass.We claim top in multicast tree and the link that does not also add multicast tree be edge link (Fig. 3 has provided an example).These links can be divided into three classes: use L
ActiveThe set of record active link, these links are back to back might selected adding multicast tree in next step, and its top is in multicast tree, and terminal is not in multicast tree.Use L
FaintThe set of expression dormancy link, these links temporarily can not add multicast tree, but become active link to certain constantly may reviving, and all in multicast tree, top can be fixed also and can not fix for their top and terminal, but terminal is certain unfixing.Remaining edge link is exactly dead link, does not need record.Every active link e=(u v) has a label Label (e), and to be source node add it self expense to the distance of its top on multicast tree to label value, promptly label (e)=Dist (s, u)+Cost (u, v).Each link of label value minimum of always selecting adds multicast tree.
Owing to do not consider the decay of link, so for every link, Anywhere signal power is identical on it to signal.We write down the interim power of giving an active link with Power (e).When an active link (u, when top v) is the node with multicast-capable (MC), the interim power of this link be Power (w, u)/(k+1); When the top of active link is a node that does not have multicast-capable (MI), the interim power of this link be Power (w, u).Wherein, (w u) is that (k is (w, the number of fixedly immediate successor u) for u, the v) direct predecessor in multicast tree (Fig. 4 has provided an example of direct predecessor and immediate successor).The starting point of assignment is like this, for the MC node, if (u, v) finally be fixed with multicast tree in, then (w, u) total k+1 immediate successor in multicast tree, the power that each immediate successor is assigned to be Power (w, u)/(k+1); And for the MI node, final (w u) at most only has an immediate successor to be fixed, this immediate successor obtain it all power P ower (w, u).Fig. 5 has provided an example that distributes temporary signal power for active link.
For the link that adds multicast tree and all active links, write down interim minimum power limits above it with PowConst (e).For the link that adds multicast tree (u, v), if it has fixing immediate successor, then its interim minimum power limits be PowConst (u, v)=kmax
(v, z)PowConst (v, z) }, (v z) is the link that is sent by v in the multicast tree, and k is (u, the number of fixedly immediate successor v); If (u v) has not been fixed on the immediate successor in the multicast tree, and then its interim minimum power limits is 1.For active link, if its top is the MI node, its interim minimum power limits is 1; If its top is the MC node, its interim minimum power limits be PowConst (v, w)=max
(v, z)PowConst (v, z) }.The reason of She Dinging is that the adding that will guarantee new link can not destroy the Power Limitation of fixed link like this, also we can say conversely, if the affiliation that adds of new link destroys original Power Limitation, then it just can not add.Fig. 6 has provided an example determining interim power lower limit.
Provide after more above-mentioned variablees, our Route Selection and Wavelength allocation method can be described below:
(1) setting the multicast forest be sky, promptly F (s, D)=φ; All destination nodes all do not add multicast forest, i.e. D
Not=D.Select a wavelength to begin to make up a multicast tree by certain rule.
(2) begin to make up multicast tree from source node s, will join active link set L from the link that s sends
Active={ e|e=(s) }, and the label of setting them is Label (e)=cost (e), interim power is Power (s)=P, is limited to PowConst (s)=1 under the interim power.
(3) from active link set, select the label value minimum a link e=(u, v), check and whether satisfy Power (u, v)〉PowConst (u, v).If do not satisfy, then from L
ActiveIn all links of sending from u of deletion, and a link reselecting the label value minimum from the residue active link is checked.If satisfy then with e=(u v) joins current multicast tree, make Dist (v)=Dist (μ)+Cost (u, v).
(4) check (u, v) whether terminal v is destination node to link e=.If then make D
Not=D
Not-v}, and carried out for (6) step; If not, then carried out for (5) step.
(5) check whether u is the node with multicast-capable (MC).If, make Power (u, v)=Power (w, u)/(k+1); If not, make Power (u, v)=(w, u), wherein (w u) is the link that has added multicast tree to link to Power.Upgrade L
ActiveAnd L
Faint: will by u send and terminal not the link in multicast tree add L
Active, will by u send and terminal in multicast tree but be not that the link of stationary nodes adds L
Faint, and will be that the active link of terminal changes the dormancy link into u, other link that is sent by u is designated as dead link.Be the new L that adds
ActiveIn link label, its value is for Label (e)=Dist (u)+Cost (e).Carried out for (8) step.
(6) node and link on will the path from source node s to this destination node be fixed on the multicast tree.Other branch that the node that do not have multicast-capable (MI) of deletion from this paths sends, and upgrade L
ActiveAnd L
FaintUpgrade the temporary signal power and the temporary signal power lower limit of each link.
(7) check D
NotWhether=φ sets up.If set up, current multicast tree is pruned, cut off the link that can not arrive destination node, output multicast forest.If be false, carried out for (8) step.
(8) whether the Survey Operations link set is empty.If empty, select a wavelength again for use, carried out for (2) step; If not empty, carried out for (3) step.
Claims (3)
1, a kind of interior multicast RWA method of all optical network with signal power decay restriction is characterized in that: consider signal power and minimum signal power restriction on the link when carrying out multicast Route Selection and Wavelength Assignment; Concrete steps are as follows:
Step 1, from wavelength available set, choose a wavelength,, on the logical network topology of this wavelength, set up a multicast tree from source node;
Step 2, when the top of a link has added multicast tree and link itself does not add multicast tree, claim that then this link is the edge link; To be divided three classes from the edge link that source node sends: active link, dormancy link, dead link; Active link is that top is source node or for non-source node with multicast-capable or for adding the non-source node of multicast tree and loose no multicast-capable, and terminal is the edge link of the node that do not add multicast tree; The dormancy link is that top is source node or for non-source node with multicast-capable or for adding the non-source node of multicast tree and loose no multicast-capable, terminal is for having added the edge link of multicast tree and loose node; Remaining edge link is dead link, and these links satisfy in following two conditions at least: top is for fixing non-source node, and perhaps terminal is fixing arbitrary node;
Step 3, distribute an interim power P ower (e) and an interim lower limit power P owConst (e) for every active link e;
Step 4, specify a label for each bar active link, numerical value that label is marked equals by source node to link e=(u, the distance D ist (u) of top v) on multicast tree adds it self cost Cost (e), Label (e)=Dist (u)+Cost (e);
Step 5, (u v), judges whether inequality Power (e) 〉=PowConst (e) sets up to choose a link e=of label value minimum from active link set; If set up, (u v) adds multicast tree, and the edge link that sends from v is classified according to the described principle of step 2; If be false, with (u v) deletes from the active link set, reselects the link of label value minimum;
Step 6, when destination node adds multicast tree, node and link on will the path from source node to this destination node be fixed on the multicast tree, other branches that will send from the no multicast-capable node on this paths are deleted from multicast tree, and the set of three types of edge link is upgraded according to principle described in the step 2;
Step 7, when there not being the active link optional time, leave out the link that does not arrive destination node in the current multicast tree, choose again a wavelength to the residue destination node begin to make up a multicast tree from source node again; Repeat above process, stop when one of following two kinds of situations take place: all in certain multicast tree, the resultant set that gets multicast tree this moment is institute and asks each destination node; Do not have wavelength optional, this moment, network blocked.
2, according to the described method of claim 1, it is characterized in that: in described step 3, specify a temporary signal power lower limit for every active link: if active link (u, top v) is the MI node, then is limited to 1 under its interim power; If its top is the MC node, then be limited under its interim power PowConst (v, w)=max
(v, z)PowConst (v, z) }.
3, according to the described method of claim 1, it is characterized in that: in described step 3, specify a temporary signal power for each bar active link: if active link (u, top u v) is the MC node, then its interim power be Power (u, v)=Power (w, u)/(k+1), wherein k is (w, fixedly immediate successor number u); If active link (u, top u v) is the MI node, then its interim power be Power (u, v)=Power (w, u).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100839010A CN101547381B (en) | 2009-05-08 | 2009-05-08 | Multicast RWA method with signal power attenuation limit in all-optical network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100839010A CN101547381B (en) | 2009-05-08 | 2009-05-08 | Multicast RWA method with signal power attenuation limit in all-optical network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101547381A true CN101547381A (en) | 2009-09-30 |
| CN101547381B CN101547381B (en) | 2011-08-24 |
Family
ID=41194201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100839010A Expired - Fee Related CN101547381B (en) | 2009-05-08 | 2009-05-08 | Multicast RWA method with signal power attenuation limit in all-optical network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101547381B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105007223A (en) * | 2015-07-16 | 2015-10-28 | 南京邮电大学 | Optical network dynamic multicast routing wavelength allocation method based on optical hierarchical structure |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1324830C (en) * | 2002-10-24 | 2007-07-04 | 上海交通大学 | Expandable multicasting light exchange structure with light-regulating shunt |
| CN1255995C (en) * | 2003-07-24 | 2006-05-10 | 华中科技大学 | Full optical wavelength route cross module |
| CN100531445C (en) * | 2004-10-19 | 2009-08-19 | 北京邮电大学 | Controlling method for realizing automatic discovery of resource information based on automatic switched optical network |
| CN101009530B (en) * | 2006-01-23 | 2012-02-15 | 华为技术有限公司 | Passive optical network, multiplexing/de-multiplexing device and method supporting the multicast service |
-
2009
- 2009-05-08 CN CN2009100839010A patent/CN101547381B/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105007223A (en) * | 2015-07-16 | 2015-10-28 | 南京邮电大学 | Optical network dynamic multicast routing wavelength allocation method based on optical hierarchical structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101547381B (en) | 2011-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ali et al. | Cost-effective implementation of multicasting in wavelength-routed networks | |
| CN101459469B (en) | Optical layer scheduling method for network element and network management control system | |
| CN103107941B (en) | Cable resource autodispatcher and method | |
| EP1533941A2 (en) | Availability aware cost modeling for optical core networks | |
| Żukowski et al. | Cost analysis of rural roll-out using a long-reach passive optical network: trading off the upfront cost under uncertainty of the user take-up rate | |
| CN105007223A (en) | Optical network dynamic multicast routing wavelength allocation method based on optical hierarchical structure | |
| CN101547381B (en) | Multicast RWA method with signal power attenuation limit in all-optical network | |
| Naeem et al. | Fiber to the Home (FTTH) Automation Planning, Its Impact on Customer Satisfaction & Cost-Effectiveness | |
| CN101179485B (en) | Route selecting method of new adding multicast member | |
| CN104753694B (en) | A kind of method and apparatus of optical cable automation Route Selection | |
| Hamad et al. | Routing and wavelength assignment with power aware multicasting in WDM networks | |
| CN103607670B (en) | A kind of passive optical network optimization method | |
| Chen et al. | Multicast routing and wavelength assignment with delay constraints in WDM networks with heterogeneous capabilities | |
| CN102907053B (en) | Wavelength division network planning method and equipment | |
| Gadkar et al. | Dynamic multicasting in WDM optical unicast networks for bandwidth-intensive applications | |
| Cabral et al. | Wide area telecommunication network design: application to the Alberta SuperNet | |
| Sun et al. | Research on routing and wavelength assignment based on hypergraph | |
| Zhou et al. | Power optimal design of multicast light-trees in WDM networks | |
| Oleksii et al. | Software modelling complex of network operating parameters with variable input data | |
| Correia et al. | Automatic Design of Telecom Networks with Genetic Algorithms | |
| Zhao et al. | Topology Optimization of Optical Transport Network Based on Network Value | |
| Gadkar et al. | Static multicast overlay in WDM unicast networks for large-scale scientific applications | |
| Atta et al. | Sub-tree Pair Selection for Reconfiguration of a Light-tree Pair | |
| Duran et al. | Multiobjective genetic algorithm to design cost-efficient wavelength-routed optical networks | |
| Gborgenu et al. | Achieving efficiency in gas pipeline connection: evidence from Ghana |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110824 Termination date: 20140508 |