OPTICAL NETWORKS. Virtual Topology Design. A. Gençata İTÜ, Dept. Computer Engineering 2005

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "OPTICAL NETWORKS. Virtual Topology Design. A. Gençata İTÜ, Dept. Computer Engineering 2005"

Transcription

1 OPTICAL NETWORKS Virtual Topology Design A. Gençata İTÜ, Dept. Computer Engineering 2005

2 Virtual Topology A lightpath provides single-hop communication between any two nodes, which could be far apart in the physical topology. However, having limited number of wavelengths, it may not be possible to set up lightpaths between all user pairs. Multi-hopping between lightpaths may be necessary. The virtual topology consists of a set of lightpaths. packets of information are carried by the virtual topology as far as possible in the optical domain using optical circuit switching packet forwarding from lightpath to lightpath is performed via electronic packet switching, whenever required. Lightpaths in the virtual topology is set up using RWA techniques. The virtual topology is also referred to as Lambda Grid, or just Grid. 2

3 Problem An optimization problem to optimally select a virtual topology subject to transceiver (transmitter and receiver) wavelength constraints with one of two possible objective functions: 1. for a given traffic matrix, minimize the network-wide average packet delay. 2. maximize the scale factor by which the traffic matrix can be scaled up (to provide the maximum capacity upgrade for future traffic demands). Since the objective functions are nonlinear and since simpler versions of the problem have been shown to be NP-hard, we shall explore heuristic approaches. 3

4 NSFNET Backbone 4

5 General Problem Statement Problem: Embedding a desired virtual topology on a given physical topology (fiber network). We are given: A physical topology G p = (V,E p ) consisting of a weighted undirected graph, where V is the set of network nodes, E p is the set of links connecting the nodes. Undirected means that each link in the physical topology is bidirectional. A node i is equipped with a D p (i) D p (i) WRS, where Dp(i) is the number of physical fiber links emanating out of (as well as terminating at) node i. 5

6 General Problem Statement Number of wavelengths carried by each fiber, M. An N N traffic matrix, where N is the number of network nodes, The (i, j)-th element is the average rate of packet traffic flow from node i to node j. The traffic flows may be asymmetric. The number of wavelength-tunable lasers (transmitters) and wavelength-tunable filters (receivers) at each node. 6

7 General Problem Statement The goal is to determine: A virtual topology G v = (V,E v ) as another graph where: the out-degree of a node is the number of transmitters at that node the in-degree of a node is the number of receivers at that node. The nodes of the virtual topology correspond to the nodes in the physical topology. Each link in the virtual topology corresponds to a lightpath between the corresponding nodes in the physical topology. Each lightpath may be routed over one of several possible paths on the physical topology. 7

8 General Problem Statement A wavelength assignment for lightpaths. If two lightpaths share a common physical link, they must necessarily employ different wavelengths. The sizes and configurations of the WRSs at the intermediate nodes. Once the virtual topology is determined and the wavelength assignments have been performed, the switch sizes and configurations follow directly. 8

9 Packet Communication Communication between any two nodes takes place by following a path (a sequence of lightpaths) from the source node to the destination node on the virtual topology. Each intermediate node in the path must perform: 1. an opto-electronic conversion, 2. electronic routing (or packet switching in the electronic domain), and 3. electro-optic forwarding onto the next lightpath. 9

10 Illustrative Example How WDM can be used to upgrade an existing fiber-based network. Using the NSFNET as an example, a hypercube can be embedded as a virtual topology over this physical topology. We assume an undirected virtual topology. bidirectional lightpaths In general, the virtual topology may be a directed graph. The physical topology is enhanced by adding two fictitious nodes, AB and XY. 10

11 Illustrative Example The switching architecture of nodes consists of: An optical component. a wavelength-routing switch (WRS) can switch some lightpaths, can locally terminate some other lightpaths by directing them to node s electronic component. An electronic component. an electronic packet router (may be an IP router: IP-over-WDM) serves as a store-and forward electronic overlay on top of the optical virtual topology. 11

12 Example The virtual topology chosen is a 16-node hypercube. 12

13 Example: A Possible Embedding 13

14 Example This solution requires 7 wavelengths. Each link in the virtual topology is a lightpath with electronic terminations at its two ends only. Example: The CA1-NE lightpath could be set up as an optical channel on one of several possible wavelengths on one of several possible physical paths: CA1-UT-CO-NE, or CA1-WA-IL-NE, or others. According to the solution, the first path is chosen on wavelength 2 for CA1-NE lightpath. This means that the WRSs at the UT and CO nodes must be properly configured to establish this CA1-NE lightpath. The switch at UT must have wavelength 2 on its fiber to CA1 connected to wavelength 2 on its fiber to CO. Since connections are bidirectional, the CA1-NE connection implies two lightpaths, one from CA1 to NE and one from NE to CA1. 14

15 UT Node 15

16 UT Node The switch UT has to support four incoming fibers plus four outgoing fibers, one each to nodes AB, CA1, CO, and MI, as dictated by the physical topology. In general, each switch interfaces with four lasers (inputs) and four filters (outputs), each laser-filter pair is dedicated to accommodate each of the four virtual links on the virtual topology. The labels 1l 2b 3d 5l on the output fiber to CO: The UT-CO fiber uses four wavelengths 1, 2, 3, and 5. Wavelengths 2 and 3 are clear channels through the UT switch and directed to the physical neighbors CA1 and MI, respectively. Wavelengths 1 and 5 connect to two local lasers. 16

17 UT Node The box labeled Router is an electronic switch which takes information from: terminated lightpaths (1c 4b 5c) a local source and routes them via electronic packet switching to: the local destination the local lasers (lightpath originators) The router can be any electronic switch. e.g., an IP router. The non-router portions of the node architecture are the optical parts that may be incorporated to upgrade the electronic switch to incorporate a WRS. 17

18 Formulation of the Optimization Problem Notation: s and d used as subscript or superscript to denote source and destination of a packet, respectively. i and j denote originating and terminating nodes, respectively, in a lightpath. m and n denote endpoints of a physical link. 18

19 Formulation: Given Given: Number of nodes in the network: N. Maximum number of wavelengths per fiber: M Physical topology P mn P mn = P nm = 1 if there is a direct physical fiber link between nodes m and n P mn = P nm = 0 otherwise The problem can be generalized to accommodate multi-fiber networks, where P mn can take integer values. 19

20 Formulation: Given Distance matrix whose elements are fiber distance d mn from node m to node n. For simplicity in expressing packet delays, dmn is expressed as a propagation delay (in time units). d mn = d nm d mn = 0 if P mn = 0. Number of transmitters at node i = T i (T i 1). Number of receivers at node i = R i (R i 1). Capacity of each channel: C normally expressed in bits per second, but converted to units of packets per second by knowing the mean packet length. 20

21 Formulation: Given Traffic matrix λ sd the average rate of traffic flow from node s to node d λ ss = 0 Additional assumptions: Packet inter-arrival durations at node s and packet lengths are exponentially distributed. So standard M/M/1 queuing results can be applied to each network link (or hop ) by employing the independence assumption on inter-arrivals and packet lengths due to traffic multiplexing at intermediate hops. By knowing the mean packet length (in bits per packet), the λ sd can be expressed in units of packets per second. 21

22 Formulation: Variables Variables: Virtual topology V ij : 1 if there is a lightpath from i to j in the virtual topology 0 otherwise. The formulation is general since lightpaths are not necessarily assumed to be bidirectional. V ij = 1 V ji = 1. Further generalization of the problem can be performed by allowing multiple lightpaths between node pairs, i.e., Vij > 1. 22

23 Formulation: Variables Traffic routing variable λ sd ij denotes the traffic flowing from s to d and employing V ij as an intermediate virtual link. traffic from s to d may be bifurcated with different fractions taking different sets of lightpaths. Physical-topology route variable p ij mn is: 1 if the fiber link P mn is used in the lightpath V ij ; 0 otherwise. Wavelength color variable c ij k is: 1 if a lightpath from i to j is assigned the color k 0 otherwise. 23

24 Formulation: Constraints Constraints: On virtual-topology connection matrix V ij : These equations ensure that: The number of lightpaths emanating out of and terminating at a node are at most equal to that node s out-degree and in-degree, respectively. 24

25 Formulation: Constraints On physical route variables p ij mn: First two equations constrain the problem so that p ij mn exist only if there is a fiber (m,n) and a lightpath (i,j). The remaining equations are the multi-commodity equations that account for the routing of a lightpath from its origin to its termination. 25

26 Formulation: Constraints On virtual-topology traffic variables λ sd ij : Equations for the routing of packet traffic on the virtual topology. They take into account that the combined traffic flowing through a channel cannot exceed the channel capacity. 26

27 Formulation: Constraints On coloring of lightpaths c ij k : First equation requires that a lightpath be of one color only. Second equation ensures that the colors used in different lightpaths are mutually exclusive over a physical link. 27

28 Formulation: Objective 1 Delay Minimization: The innermost brackets: the first component corresponds to the propagation delays on the links mn which form the lightpath ij the second component corresponds to delay due to queuing and packet transmission on lightpath ij. If we assume shortest-path routing of the lightpaths over the physical topology, then the p ij mn values become deterministic. If, in addition, we neglect queuing delays, the optimization problem reduces to minimizing the first component. 28

29 Formulation: Objective 2 Maximizing Load (Minimizing Maximum Flow): Also nonlinear Minimizes the maximum amount of traffic that flows through any lightpath. Corresponds to obtaining a virtual topology which can maximize the offered load to the network if the traffic matrix is allowed to be scaled up. 29

30 Algorithms for VT Design The problem of optimal virtual-topology design can be partitioned into the following four subproblems, which are not necessarily independent: Determine a good virtual topology. which transmitter should be directly connected to which receiver? Route the lightpaths over the physical topology. Assign wavelengths optimally to the various lightpaths. Route packet traffic on the virtual topology. 30

31 Solutions Several heuristic approaches have been employed to solve these problems. Labourdette and Acampora, Logically rearrangeable multihop lightwave networks, IEEE Transactions on Comm., Aug I. Chlamtac, A. Ganz, and G. Karmi, Lightnets: Topologies for high speed optical networks, IEEE/OSA Journal of Lightwave Technology, May/June B. Mukherjee, S. Ramamurthy, D. Banerjee, and A. Mukherjee, Some principles for designing a wide-area optical network, Proceedings, IEEE INFOCOM 94, June R. Ramaswami and K. Sivarajan, Design of logical topologies for wavelength-routed all-optical networks, Proceedings, IEEE INFOCOM 95, April Z. Zhang and A. Acampora, A heuristic wavelength assignment algorithm for multihop WDM networks with wavelength routing and wavelength reuse, IEEE/ACM Transactions on Networking, vol. 3, pp , June

32 Solutions Embedding of a packet-switched virtual topology on a physical fiber plant in a switched network was first introduced in the second reference, and this network architecture was referred to as a lightnet. The work in ref. 4 proposes a virtual-topology design where the average hop distance is minimized, which automatically increases the network traffic supported. This work uses the physical topology as a subset of the virtual topology. 32

33 Solution Approach To obtain a thorough understanding of the problem, we concentrate on Sub-problems 1 and 4 above. the number of available wavelengths is not a constraint. In the expanded problem, both the number of wavelengths and their exact assignments are critical. An iterative approach consisting of simulated annealing to search for a good virtual topology (Sub-problem 1) The flow-deviation algorithm for optimal (possibly bifurcated ) routing of packet traffic on the virtual topology (Sub-problem 4). 33

34 Solution Approach We will consider lightpaths to be bidirectional in our solution here most (Internet) network protocols rely on bidirectional paths and links. We consider Optimization Criterion (2) (maximizing offered load) for our illustrative solution. mainly because we are interested in upgrading an existing fiber-based network to a WDM solution. 34

35 Simulated Annealing Simulated annealing (along with genetic algorithms) has been found to provide good solutions for complex optimization problems. In the simulated annealing process, the algorithm starts with an initial random configuration for the virtual topology. Node-exchange operations are used to arrive at neighboring configurations. In a node-exchange operation, adjacent nodes in the virtual topology are examined for swapping. Example: if node i is connected to nodes j, a, and b, while node j is connected to nodes p, q, and i in the virtual topology, after the node-exchange operation between nodes i and j, node i will be connected to nodes p, q, and j, while node j will be connected to nodes a, b, and i. 35

36 Simulated Annealing Neighboring configurations which give better results (lower average packet delay) than the current solution are accepted automatically. Solutions which are worse than the current one are accepted with a certain probability. This probability is determined by a system control parameter. The probability with which these failed configurations are chosen decreases as the algorithm progresses in time so as to simulate the cooling process of annealing. The probability of acceptance is based on a negative exponential factor inversely proportional to the difference between the current solution and the best solution obtained so far. 36

37 Simulated Annealing The initial stages of the annealing process examine random configurations in the search space to obtain different initial starting configurations without getting stuck at a local minimum as in a greedy approach. However, as time progresses, the probability of accepting bad solutions goes down, the algorithm settles down into a minimum, after several iterations. The state become frozen when there is no improvement in the objective function of the solution after a large number of iterations. 37

38 Flow Deviation By properly adjusting link flows, the flow-deviation algorithm provides an optimal algorithm for minimizing the network-wide average packet delay. Traffic from a given source to a destination may be bifurcated. different fractions of it may be routed along different paths to minimize the packet delay. Idea: If the flows are not balanced, then excessively loading of a particular channel may lead to large delays on that channel and thus have a negative influence on the network-wide average packet delay. 38

39 Flow Deviation The algorithm is based on the notion of shortest-path flows. First calculates the linear rate of increase in the delay with an infinitesimal increase in the flow on any particular channel. These lengths or cost rates are used to pose a shortest-path flow problem (can be solved using one of several well-known algorithms such as Dijkstra s algorithm, Bellman-Ford algorithm, etc.) The resulting paths represent the cheapest paths on which some of the flow may be deviated. An iterative algorithm determines how much of the original flow needs to be deviated. The algorithm continues until a certain performance tolerance level is reached. 39

40 Experimental Results The traffic matrix employed is an actual measurement of the traffic on the NSFNET backbone for a 15-minute period. 11:45 pm to midnight on January 12, 1992, EST. The raw traffic matrix shows traffic flow in bytes per 15- minute intervals between network nodes. Nodal distances used are the actual geographical distances. Initially, each node can set up at most four bidirectional lightpath channels. Later more experiments were conducted to study the effect of having higher nodal degree. The number of wavelengths per fiber was assumed to be large enough. all possible virtual topologies could be embedded. 40

41 Traffic Matrix 41

42 For each experiment, Experimental Results the maximum scale-up achieved the corresponding individual delay components, the maximum and minimum link loading the average hop distance is tabulated. 42

43 Experimental Results The aggregate capacity for the carried traffic is fixed by the number of links in the network. reducing the average hop distance can lead to higher values of load that the network can carry. The queuing delay was calculated using a standard M/M/1 queuing system. mean packet length calculated from the measured traffic: bytes per packet. link speed is 45 Mbps. Infinite buffers at all nodes. The cooling parameter for the simulated annealing is updated after every 100 acceptances using a geometric parameter of value 0.9. A state is considered frozen when there is no improvement over 100 consecutive trials. 43

44 Physical Topology as Virtual Topology (No WDM) Goal: to obtain a fair estimate of what optical hardware can provide in terms of extra capabilities. Start off with just the existing hardware, comprising: fiber and point-to-point connections a single bidirectional lightpath channel per fiber link no WDM The maximum scale-up achieved: 49 The load of the link with the maximum traffic: 98% The load of the link with the minimum traffic: 32%. These values serve as a basis for comparison as to what can be gained in terms of throughput by adding extra WDM optical hardware: tunable transceivers wavelength routing switches. 44

45 Multiple Point-to-Point Links (No WRS) Goal: to determine how much throughput we could obtain from the network: without adding any photonic switching capability at a node by adding extra transceivers (up to four) at each node The initial network had 21 bidirectional links in the physical topology. Using extra transceivers at the nodes, extra links are set up on the paths NE-CO, NE-IL, WA-CA2, CA1-UT, MI- NJ, and NY-MD. These lightpaths are chosen manually. Different combinations were considered. The channels providing the maximum scale-up was chosen. 45

46 Arbitrary Virtual Topology (Full WDM) Full WDM with WRSs at all nodes. It is possible to set up lightpaths between any two nodes. All lightpaths are routed over the shortest path on the physical topology. Starting off with a random initial topology, simulated annealing is used to get the best virtual topology. shown in the table. Provides a maximum scale-up of 106. The increased scale-up demonstrates the benefits of the WDM-based virtual-topology approach. 46

47 Effect of Nodal Degree and Wavelength Requirements If we consider full WDM, and increase the nodal degree to five and six, we find that the maximum scale-up increases nearly proportionally with increasing nodal degree. In the experiments, the observed maximum scale-ups: for P = 5: 135 For P = 6: 163 As the nodal degree is increased, the average hop distance of the virtual topology is reduced. This provides the extra improvement in the scale-up. Minimizing hop distance can be an important optimization problem. 47

48 Open Problems A significant amount of room exists for developing improved approaches and algorithms. An interesting avenue of research is to study how routing and wavelength assignment of lightpaths can be combined with the choice of virtual topology and its corresponding packet routing in order to arrive at an optimum solution. Dynamic establishment and reconfiguration of lightpaths is an important issue which needs to be thoroughly studied. 48

Wavelength-Routed Optical Networks: Linear Formulation, Resource Budgeting Tradeoffs, and a Reconfiguration Study

Wavelength-Routed Optical Networks: Linear Formulation, Resource Budgeting Tradeoffs, and a Reconfiguration Study 598 IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 8, NO. 5, OCTOBER 2000 Wavelength-Routed Optical Networks: Linear Formulation, Resource Budgeting Tradeoffs, and a Reconfiguration Study Dhritiman Banerjee

More information

Rollout Algorithms for Logical Topology Design and Traffic Grooming in Multihop WDM Networks

Rollout Algorithms for Logical Topology Design and Traffic Grooming in Multihop WDM Networks Rollout Algorithms for Logical Topology Design and Traffic Grooming in Multihop WDM Networks Kwangil Lee Department of Electrical and Computer Engineering University of Texas, El Paso, TX 79928, USA. Email:

More information

A New Architecture for Multihop Optical Networks

A New Architecture for Multihop Optical Networks A New Architecture for Multihop Optical Networks A. Jaekel 1, S. Bandyopadhyay 1 and A. Sengupta 2 1 School of Computer Science, University of Windsor Windsor, Ontario N9B 3P4 2 Dept. of Computer Science,

More information

IO2654 Optical Networking. WDM network design. Lena Wosinska KTH/ICT. The aim of the next two lectures. To introduce some new definitions

IO2654 Optical Networking. WDM network design. Lena Wosinska KTH/ICT. The aim of the next two lectures. To introduce some new definitions IO2654 Optical Networking WDM network design Lena Wosinska KTH/ICT 1 The aim of the next two lectures To introduce some new definitions To make you aware about the trade-offs for WDM network design To

More information

Adaptive Weight Functions for Shortest Path Routing Algorithms for Multi-Wavelength Optical WDM Networks

Adaptive Weight Functions for Shortest Path Routing Algorithms for Multi-Wavelength Optical WDM Networks Adaptive Weight Functions for Shortest Path Routing Algorithms for Multi-Wavelength Optical WDM Networks Tibor Fabry-Asztalos, Nilesh Bhide and Krishna M. Sivalingam School of Electrical Engineering &

More information

I R TECHNICAL RESEARCH REPORT. A Local Optimization Algorithm for Logical Topology Design and Traffic Grooming in IP over WDM Networks

I R TECHNICAL RESEARCH REPORT. A Local Optimization Algorithm for Logical Topology Design and Traffic Grooming in IP over WDM Networks TECHNICAL RESEARCH REPORT A Local Optimization Algorithm for Logical Topology Design and Traffic Grooming in IP over WDM Networks by Kwang-Il Lee, Mark Shayman TR 2003-3 I R INSTITUTE FOR SYSTEMS RESEARCH

More information

A Wavelength Sharing and Assignment Heuristic to Minimize the Number of Wavelength Converters in Resilient WDM Networks

A Wavelength Sharing and Assignment Heuristic to Minimize the Number of Wavelength Converters in Resilient WDM Networks A Wavelength Sharing and Assignment Heuristic to Minimize the Number of Wavelength Converters in Resilient WDM Networks Shreejith Billenahalli, Miguel Razo, Wanjun Huang, Arularasi Sivasankaran, Limin

More information

A Novel Generic Graph Model for Traffic Grooming in Heterogeneous WDM Mesh Networks

A Novel Generic Graph Model for Traffic Grooming in Heterogeneous WDM Mesh Networks IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 11, NO. 2, APRIL 2003 285 A Novel Generic Graph Model for Traffic Grooming in Heterogeneous WDM Mesh Networks Hongyue Zhu, Student Member, IEEE, Hui Zang, Member,

More information

Designing WDM Optical Networks using Branch-and-Price

Designing WDM Optical Networks using Branch-and-Price Designing WDM Optical Networks using Branch-and-Price S. Raghavan Smith School of Business & Institute for Systems Research University of Maryland College Park, MD 20742 raghavan@umd.edu Daliborka Stanojević

More information

Multiconfiguration Multihop Protocols: A New Class of Protocols for Packet-Switched WDM Optical Networks

Multiconfiguration Multihop Protocols: A New Class of Protocols for Packet-Switched WDM Optical Networks Multiconfiguration Multihop Protocols: A New Class of Protocols for Packet-Switched WDM Optical Networks Jason P. Jue, Member, IEEE, and Biswanath Mukherjee, Member, IEEE Abstract Wavelength-division multiplexing

More information

Link Selection Algorithms for Link-Based ILPs and Applications to RWA in Mesh Networks

Link Selection Algorithms for Link-Based ILPs and Applications to RWA in Mesh Networks Link Selection Algorithms for Link-Based ILPs and Applications to RWA in Mesh Networks Zeyu Liu, George N. Rouskas Department of Computer Science, North Carolina State University, Raleigh, NC 27695-8206,

More information

Some economical principles

Some economical principles Hints on capacity planning (and other approaches) Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ Some economical principles Assume users have

More information

Capacity planning and.

Capacity planning and. Hints on capacity planning (and other approaches) Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ Some economical principles Assume users have

More information

MatPlanWDM: An educational tool for network planning in wavelength-routing networks

MatPlanWDM: An educational tool for network planning in wavelength-routing networks MatPlanWDM: An educational tool for network planning in wavelength-routing networks P. Pavon-Mariño, R. Aparicio-Pardo, G. Moreno-Muñoz, J. Garcia-Haro, J. Veiga-Gontan Department of Information Technologies

More information

Iterative Optimization in VTD to Maximize the Open Capacity of WDM Networks

Iterative Optimization in VTD to Maximize the Open Capacity of WDM Networks Iterative Optimization in VTD to Maximize the Open Capacity of WDM Networks Karcius D.R. Assis, Marcio S. Savasini and Helio Waldman DECOM/FEEC/UNICAMP, CP. 6101, 13083-970 Campinas, SP-BRAZIL Tel: +55-19-37883793,

More information

Design of Large-Scale Optical Networks Λ

Design of Large-Scale Optical Networks Λ Design of Large-Scale Optical Networks Λ Yufeng Xin, George N. Rouskas, Harry G. Perros Department of Computer Science, North Carolina State University, Raleigh NC 27695 E-mail: fyxin,rouskas,hpg@eos.ncsu.edu

More information

OPTICAL NETWORKS. Optical Metro Networks. A. Gençata İTÜ, Dept. Computer Engineering 2005

OPTICAL NETWORKS. Optical Metro Networks. A. Gençata İTÜ, Dept. Computer Engineering 2005 OPTICAL NETWORKS Optical Metro Networks A. Gençata İTÜ, Dept. Computer Engineering 2005 Introduction Telecommunications networks are normally segmented in a three-tier hierarchy: Access, metropolitan,

More information

Dynamic Wavelength Assignment for WDM All-Optical Tree Networks

Dynamic Wavelength Assignment for WDM All-Optical Tree Networks Dynamic Wavelength Assignment for WDM All-Optical Tree Networks Poompat Saengudomlert, Eytan H. Modiano, and Robert G. Gallager Laboratory for Information and Decision Systems Massachusetts Institute of

More information

Capacity planning and.

Capacity planning and. Some economical principles Hints on capacity planning (and other approaches) Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ Assume users have

More information

WAVELENGTH-DIVISION multiplexing (WDM) is a

WAVELENGTH-DIVISION multiplexing (WDM) is a 2854 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 23, NO. 10, OCTOBER 2005 Traffic-Based Reconfiguration for Logical Topologies in Large-Scale WDM Optical Networks Yongbing Zhang, Member, IEEE, Masaki Murata,

More information

Splitter Placement in All-Optical WDM Networks

Splitter Placement in All-Optical WDM Networks plitter Placement in All-Optical WDM Networks Hwa-Chun Lin Department of Computer cience National Tsing Hua University Hsinchu 3003, TAIWAN heng-wei Wang Institute of Communications Engineering National

More information

LIGHT TREE A SEMINAR REPORT. Submitted By SUJIT KUMAR. In partial fulfillment of the award of the degree BACHELOR OF TECHNOLOGY

LIGHT TREE A SEMINAR REPORT. Submitted By SUJIT KUMAR. In partial fulfillment of the award of the degree BACHELOR OF TECHNOLOGY LIGHT TREE A SEMINAR REPORT Submitted By SUJIT KUMAR In partial fulfillment of the award of the degree of BACHELOR OF TECHNOLOGY IN COMPUTER SCIENCE AND ENGINEERING SCHOOL OF ENGINEERING COCHIN UNIVERSITY

More information

Performance of Multi Hop Communications Using Logical Topologies on Optical Torus Networks

Performance of Multi Hop Communications Using Logical Topologies on Optical Torus Networks Performance of Multi Hop Communications Using Logical Topologies on Optical Torus Networks Xin Yuan Rami Melhem Rajiv Gupta Dept. of Computer Science Dept. of Computer Science Dept. of Computer Science

More information

A Heuristic Algorithm for Designing Logical Topologies in Packet Networks with Wavelength Routing

A Heuristic Algorithm for Designing Logical Topologies in Packet Networks with Wavelength Routing A Heuristic Algorithm for Designing Logical Topologies in Packet Networks with Wavelength Routing Mare Lole and Branko Mikac Department of Telecommunications Faculty of Electrical Engineering and Computing,

More information

Dynamic Routing and Resource Allocation in WDM Transport Networks

Dynamic Routing and Resource Allocation in WDM Transport Networks Dynamic Routing and Resource Allocation in WDM Transport Networks Jan Späth University of Stuttgart, Institute of Communication Networks and Computer Engineering (IND), Germany Email: spaeth@ind.uni-stuttgart.de

More information

William Stallings Data and Computer Communications. Chapter 10 Packet Switching

William Stallings Data and Computer Communications. Chapter 10 Packet Switching William Stallings Data and Computer Communications Chapter 10 Packet Switching Principles Circuit switching designed for voice Resources dedicated to a particular call Much of the time a data connection

More information

Contention-based Limited Deflection Routing in OBS Networks

Contention-based Limited Deflection Routing in OBS Networks Contention-based Limited Deflection Routing in OBS Networks SuKyoung Lee, Kotikalapudi Sriram, HyunSook Kim and JooSeok Song Sejong University, Seoul, Korea NIST, Gaithersburg, USA Yonsei University, Seoul,

More information

n = 2 n = 1 µ λ n = 0

n = 2 n = 1 µ λ n = 0 A Comparison of Allocation Policies in Wavelength Routing Networks Yuhong Zhu, George N. Rouskas, Harry G. Perros Department of Computer Science, North Carolina State University Abstract We consider wavelength

More information

A Novel Optimization Method of Optical Network Planning. Wu CHEN 1, a

A Novel Optimization Method of Optical Network Planning. Wu CHEN 1, a A Novel Optimization Method of Optical Network Planning Wu CHEN 1, a 1 The engineering & technical college of chengdu university of technology, leshan, 614000,china; a wchen_leshan@126.com Keywords:wavelength

More information

Rollout Algorithms for Integrated Topology Control and Routing in Wireless Optical Backbone Networks. by Abhishek Kashyap, Kwangil Lee, Mark Shayman

Rollout Algorithms for Integrated Topology Control and Routing in Wireless Optical Backbone Networks. by Abhishek Kashyap, Kwangil Lee, Mark Shayman TECHNICAL RESEARCH REPORT Rollout Algorithms for Integrated Topology Control and Routing in Wireless Optical Backbone Networks by Abhishek Kashyap, Kwangil Lee, Mark Shayman TR 2003-51 I R INSTITUTE FOR

More information

ADAPTIVE LINK WEIGHT ASSIGNMENT AND RANDOM EARLY BLOCKING ALGORITHM FOR DYNAMIC ROUTING IN WDM NETWORKS

ADAPTIVE LINK WEIGHT ASSIGNMENT AND RANDOM EARLY BLOCKING ALGORITHM FOR DYNAMIC ROUTING IN WDM NETWORKS ADAPTIVE LINK WEIGHT ASSIGNMENT AND RANDOM EARLY BLOCKING ALGORITHM FOR DYNAMIC ROUTING IN WDM NETWORKS Ching-Lung Chang, Yan-Ying, Lee, and Steven S. W. Lee* Department of Electronic Engineering, National

More information

Research Article Comparative Analysis of Routing and Wavelength Assignment Algorithms used in WDM Optical Networks

Research Article Comparative Analysis of Routing and Wavelength Assignment Algorithms used in WDM Optical Networks Research Journal of Applied Sciences, Engineering and Technology 7(13): 2646-2654, 2014 DOI:10.19026/rjaset.7.581 ISSN: 2040-7459; e-issn: 2040-7467 2014 Maxwell Scientific Publication Corp. Submitted:

More information

A Review of Traffic Management in WDM Optical Networks: Progress and Challenges

A Review of Traffic Management in WDM Optical Networks: Progress and Challenges www.ijecs.in International Journal Of Engineering And Computer Science ISSN:2319-7242 Volume 6 Issue 8 August 2017, Page No. 22309-22313 Index Copernicus value (2015): 58.10 DOI: 10.18535/ijecs/v6i8.13

More information

Logical Topology Design for Linear and Ring Optical Networks

Logical Topology Design for Linear and Ring Optical Networks 62 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL 20, NO 1, JANUARY 2002 Logical Topology Design for Linear and Ring Optical Networks Amrinder S Arora, Suresh Subramaniam, Member, IEEE, and Hyeong-Ah

More information

Reconfigurations of Logical Topologies for WDM Mesh Networks

Reconfigurations of Logical Topologies for WDM Mesh Networks University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations 2010 Reconfigurations of Logical Topologies for WDM Mesh Networks Aktaruzzaman AKM University of Windsor Follow this and

More information

Distributed Clustering Method for Large-Scaled Wavelength Routed Networks

Distributed Clustering Method for Large-Scaled Wavelength Routed Networks Distributed Clustering Method for Large-Scaled Wavelength Routed Networks Yukinobu Fukushima, Hiroaki Harai, Shin ichi Arakawa, and Masayuki Murata Graduate School of Information Science and Technology,

More information

Resilient Networks. 3.1 Resilient Network Design - Intro. Mathias Fischer

Resilient Networks. 3.1 Resilient Network Design - Intro. Mathias Fischer Mathias Fischer Resilient Networks. Resilient Network Design - Intro Prepared along: Michal Pioro and Deepankar Medhi - Routing, Flow, and Capacity Design in Communication and Computer Networks, The Morgan

More information

Toward a Reliable Data Transport Architecture for Optical Burst-Switched Networks

Toward a Reliable Data Transport Architecture for Optical Burst-Switched Networks Toward a Reliable Data Transport Architecture for Optical Burst-Switched Networks Dr. Vinod Vokkarane Assistant Professor, Computer and Information Science Co-Director, Advanced Computer Networks Lab University

More information

Analysis and Algorithms for Partial Protection in Mesh Networks

Analysis and Algorithms for Partial Protection in Mesh Networks Analysis and Algorithms for Partial Protection in Mesh Networks Greg uperman MIT LIDS Cambridge, MA 02139 gregk@mit.edu Eytan Modiano MIT LIDS Cambridge, MA 02139 modiano@mit.edu Aradhana Narula-Tam MIT

More information

Admission Control in Time-Slotted Multihop Mobile Networks

Admission Control in Time-Slotted Multihop Mobile Networks dmission ontrol in Time-Slotted Multihop Mobile Networks Shagun Dusad and nshul Khandelwal Information Networks Laboratory Department of Electrical Engineering Indian Institute of Technology - ombay Mumbai

More information

A NOVEL DECENTRALIZED ETHERNET-BASED PASSIVE OPTICAL NETWORK ARCHITECTURE

A NOVEL DECENTRALIZED ETHERNET-BASED PASSIVE OPTICAL NETWORK ARCHITECTURE A NOVEL DECENTRALIZED ETHERNET-BASED PASSIVE OPTICAL NETWORK ARCHITECTURE A. Hadjiantonis, S. Sherif, A. Khalil, T. Rahman, G. Ellinas, M. F. Arend, and M. A. Ali, Department of Electrical Engineering,

More information

WAVELENGTH-DIVISION multiplexing (WDM) partitions

WAVELENGTH-DIVISION multiplexing (WDM) partitions IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 5, NO. 5, OCTOBER 1997 719 Channel Sharing in Multi-Hop WDM Lightwave Networks: Do We Need More Channels? Srini B. Tridandapani, Member, IEEE, Biswanath Mukherjee,

More information

Design of CapEx-Efficient IP-over-WDM Network using Auxiliary Matrix based Heuristic

Design of CapEx-Efficient IP-over-WDM Network using Auxiliary Matrix based Heuristic IEEE ANTS 2014 1570023335 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 60 61 62 63 64

More information

Autonomous Clustering-Based Heterogeneous Waveband Switching in WDM Networks

Autonomous Clustering-Based Heterogeneous Waveband Switching in WDM Networks Autonomous Clustering-Based Heterogeneous aveband Switching in DM Networks Mengke Li and Byrav Ramamurthy Department of Computer Science and Engineering, University of Nebraska-Lincoln, USA Email: {mli,

More information

Delivery Network on the Internet

Delivery Network on the Internet Optimal erver Placement for treaming Content Delivery Network on the Internet Xiaojun Hei and Danny H.K. Tsang Department of Electronic and Computer Engineering Hong Kong University of cience and Technology

More information

Resource Sharing for QoS in Agile All Photonic Networks

Resource Sharing for QoS in Agile All Photonic Networks Resource Sharing for QoS in Agile All Photonic Networks Anton Vinokurov, Xiao Liu, Lorne G Mason Department of Electrical and Computer Engineering, McGill University, Montreal, Canada, H3A 2A7 E-mail:

More information

Performance Analysis on Various Wavelength Assignment Algorithms with Traffic Grooming

Performance Analysis on Various Wavelength Assignment Algorithms with Traffic Grooming Proc. of Int. Conf. on Emerging Trends in Engineering and Technology Performance Analysis on Various Wavelength Assignment Algorithms with Traffic Grooming Vikas Kaushik 1, R.S Chauhan 2 1 JMIT Radaur/ECE

More information

Design of Logical Topologies in Wavelength-Routed IP Networks

Design of Logical Topologies in Wavelength-Routed IP Networks DESIGN OF LOGICAL TOPOLOGIES... 1 Design of Logical Topologies in Wavelength-Routed IP Networks M.Ajmone Marsan ½ A.Grosso ¾, E.Leonardi ½, M.Mellia ½, A.Nucci ½ ½ Dipartimento di Elettronica - Politecnico

More information

Routing and Traffic Engineering in Hybrid RF/FSO Networks*

Routing and Traffic Engineering in Hybrid RF/FSO Networks* Routing and Traffic Engineering in Hybrid RF/FSO Networks* Abhishek Kashyap and Mark Shayman Department of Electrical and Computer Engineering, University of Maryland, College Park MD 20742 Email: {kashyap,

More information

Establishment of Survivable Connections in WDM Networks using Partial Path Protection

Establishment of Survivable Connections in WDM Networks using Partial Path Protection Establishment of Survivable Connections in WDM Networks using Partial Path Protection G. Xue 1, Senior Member, IEEE, W. Zhang 1,J.Tang 1, and K. Thulasiraman 2, Fellow, IEEE Abstract As a generalization

More information

Traffic Grooming in WDM Networks

Traffic Grooming in WDM Networks TOPICS IN LIGHTWAVE SERIES Traffic Grooming in Networks Eytan Modiano, MIT Philip J. Lin, Tellabs ABSTRACT The recent emergence of wavelength-division multiplexing technology has led to a tremendous increase

More information

Dynamic service Allocation with Protection Path

Dynamic service Allocation with Protection Path www.ijcsi.org 115 Dynamic service Allocation with Protection Path Loay Alzubaidi Department of Computer Engineering & Science, Prince Muhammad bin Fahd University AL-Khobar, Saudi Arabia Abstract Path

More information

QoS routing in DWDM Optical Packet Networks

QoS routing in DWDM Optical Packet Networks QoS routing in DWDM Optical Packet Networks W. Cerroni CNIT Bologna Research Unit, ITALY F. Callegati, G. Muretto, C. Raffaelli, P. Zaffoni DEIS University of Bologna, ITALY Optical Packet Switching (OPS)

More information

Automatic Service and Protection Path Computation - A Multiplexing Approach

Automatic Service and Protection Path Computation - A Multiplexing Approach Automatic Service and Protection Path Computation - A Multiplexing Approach Loay Alzubaidi 1, Ammar El Hassan 2, Jaafar Al Ghazo 3 1 Department of Computer Engineering & Science, Prince Muhammad bin Fahd

More information

Shared Risk Link Group (SRLG)-Diverse Path Provisioning Under Hybrid Service Level Agreements in Wavelength-Routed Optical Mesh Networks

Shared Risk Link Group (SRLG)-Diverse Path Provisioning Under Hybrid Service Level Agreements in Wavelength-Routed Optical Mesh Networks University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln CSE Journal Articles Computer Science and Engineering, Department of 8-2005 Shared Risk Link Group (SRLG)-Diverse Path Provisioning

More information

Quality of Service Routing

Quality of Service Routing Quality of Service Routing KNOM Tutorial 2004, Jeju, Korea, Nov. 4-5, 2004. November 5, 2004 Kwang-Hui Lee Communication Systems Lab, Changwon National University khlee@changwon.ac.kr Contents Introduction

More information

A Hierarchical Model for Multigranular Optical Networks

A Hierarchical Model for Multigranular Optical Networks A Hierarchical Model for Multigranular Optical Networks Mohan Iyer, George N. Rouskas, Rudra Dutta {mliyer, rouskas, rdutta}@ncsu.edu Department of Computer Science, North Carolina State University, Raleigh,

More information

Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization

Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization Ryan M. Garlick 1 and Richard S. Barr 2 1 CSE Dept., Southern Methodist University, Dallas, TX 75275 USA 2 EMIS Dept., Southern Methodist

More information

The Multi-dimensional Shuffle-exchange Network: A Novel Topology for Regular Network Architectures *

The Multi-dimensional Shuffle-exchange Network: A Novel Topology for Regular Network Architectures * The Multi-dimensional Shuffle-exchange Network: A Novel Topology for Regular Network Architectures * Philip P. To Tony T. Lee Department of Information Engineering The Chinese University of Hong Kong Shatin,

More information

Latency on a Switched Ethernet Network

Latency on a Switched Ethernet Network FAQ 07/2014 Latency on a Switched Ethernet Network RUGGEDCOM Ethernet Switches & Routers http://support.automation.siemens.com/ww/view/en/94772587 This entry is from the Siemens Industry Online Support.

More information

Traffic Grooming for Survivable WDM Networks Shared Protection

Traffic Grooming for Survivable WDM Networks Shared Protection Traffic Grooming for Survivable WDM Networks Shared Protection Canhui (Sam) Ou, Keyao Zhu, Hui Zang, Laxman H. Sahasrabuddhe, and Biswanath Mukherjee Abstract This paper investigates the survivable trafficgrooming

More information

Research on Control Routing Technology in Communication Network

Research on Control Routing Technology in Communication Network Appl. Math. Inf. Sci. 6 No. 1S pp. 129S-133S (2012) Applied Mathematics & Information Sciences An International Journal @ 2012 NSP Natural Sciences Publishing Cor. Research on Control Routing Technology

More information

A Network Optimization Model for Multi-Layer IP/MPLS over OTN/DWDM Networks

A Network Optimization Model for Multi-Layer IP/MPLS over OTN/DWDM Networks A Network Optimization Model for Multi-Layer IP/MPLS over OTN/DWDM Networks Iyad Katib and Deep Medhi Computer Science & Electrical Engineering Department University of Missouri-Kansas City, USA {IyadKatib,

More information

Arista 7500E DWDM Solution and Use Cases

Arista 7500E DWDM Solution and Use Cases ARISTA WHITE PAPER Arista DWDM Solution and Use Cases The introduction of the Arista 7500E Series DWDM solution expands the capabilities of the Arista 7000 Series with a new, high-density, high-performance,

More information

Power Efficient Traffic Grooming in Optical WDM Networks

Power Efficient Traffic Grooming in Optical WDM Networks Power Efficient Traffic Grooming in Optical WDM Networks Emre Yetginer Tubitak UEKAE Ilhan Tan Kislasi Umitkoy, Ankara 06800 Turkey Email: emre.yetginer@iltaren.tubitak.gov.tr George N. Rouskas Department

More information

10. Network dimensioning

10. Network dimensioning Partly based on slide material by Samuli Aalto and Jorma Virtamo ELEC-C7210 Modeling and analysis of communication networks 1 Contents Introduction Parameters: topology, routing and traffic Dimensioning

More information

WAVELENGTH-DIVISION-MULTIPLEXING (WDM)

WAVELENGTH-DIVISION-MULTIPLEXING (WDM) JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 24, NO. 6, JUNE 2006 2267 Logical Topology Design for Dynamic Traffic Grooming in WDM Optical Networks Chunsheng Xin, Member, IEEE, Bin Wang, Member, IEEE, Xiaojun

More information

TCOM 370 NOTES 99-1 NETWORKING AND COMMUNICATIONS

TCOM 370 NOTES 99-1 NETWORKING AND COMMUNICATIONS TCOM 370 NOTES 99-1 NETWORKING AND COMMUNICATIONS Communication Networks Allow Exchange of Information between Users telephone network for voice communication interconnected computers and peripherals,

More information

Wavelength Conversion in WDM Networking

Wavelength Conversion in WDM Networking University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln CSE Journal Articles Computer Science and Engineering, Department of 9-1998 Wavelength Conversion in WDM Networking Byrav

More information

CS 204 Lecture Notes on Elementary Network Analysis

CS 204 Lecture Notes on Elementary Network Analysis CS 204 Lecture Notes on Elementary Network Analysis Mart Molle Department of Computer Science and Engineering University of California, Riverside CA 92521 mart@cs.ucr.edu October 18, 2006 1 First-Order

More information

Optical networks employing wavelength division

Optical networks employing wavelength division Multidestination communication in broadcast WDM networks: a survey Dhaval Thaker George N. Rouskas North Carolina State University Department of Computer Science Raleigh, North Carolina USA ABSTRACT In

More information

Towards a Robust and Green Internet Backbone Network

Towards a Robust and Green Internet Backbone Network Towards a Robust and Green Internet Backbone Network Xuezhou Ma Department of Computer Science North Carolina State University Email: xuezhou ma@ncsu.edu Khaled Harfoush Department of Computer Science

More information

Absolute QoS Differentiation in Optical Burst-Switched Networks

Absolute QoS Differentiation in Optical Burst-Switched Networks IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 22, NO. 9, NOVEMBER 2004 1781 Absolute QoS Differentiation in Optical Burst-Switched Networks Qiong Zhang, Student Member, IEEE, Vinod M. Vokkarane,

More information

1158 IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 18, NO. 4, AUGUST Coding-oblivious routing implies that routing decisions are not made based

1158 IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 18, NO. 4, AUGUST Coding-oblivious routing implies that routing decisions are not made based 1158 IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 18, NO. 4, AUGUST 2010 Network Coding-Aware Routing in Wireless Networks Sudipta Sengupta, Senior Member, IEEE, Shravan Rayanchu, and Suman Banerjee, Member,

More information

Latency on a Switched Ethernet Network

Latency on a Switched Ethernet Network Page 1 of 6 1 Introduction This document serves to explain the sources of latency on a switched Ethernet network and describe how to calculate cumulative latency as well as provide some real world examples.

More information

MWPG - AN ALGORITHM FOR WAVELENGTH REROUTING

MWPG - AN ALGORITHM FOR WAVELENGTH REROUTING MWPG - AN ALGORITHM FOR WAVELENGTH REROUTING Student Lecture Mohammed Pottayil 05-07-03 1 1 OUTLINE Review of Wavelength Rerouting Concepts - What is Wavelength Rerouting - Lightpath Migration operations

More information

Performance of Optical Burst Switching Techniques in Multi-Hop Networks

Performance of Optical Burst Switching Techniques in Multi-Hop Networks Performance of Optical Switching Techniques in Multi-Hop Networks Byung-Chul Kim *, You-Ze Cho *, Jong-Hyup Lee **, Young-Soo Choi **, and oug Montgomery * * National Institute of Standards and Technology,

More information

Cost Eective Trac Grooming in WDM Rings. Ori Gerstel and Rajiv Ramaswami

Cost Eective Trac Grooming in WDM Rings. Ori Gerstel and Rajiv Ramaswami Cost Eective Trac Grooming in WDM Rings Ori Gerstel and Rajiv Ramaswami Tellabs Operations Inc, Optical etwork Group, Hawthorne, Y, fori, rajivg@tellabscom Galen Sasaki U Hawaii, Dept Elec Engg, Honolulu,

More information

CH : 15 LOCAL AREA NETWORK OVERVIEW

CH : 15 LOCAL AREA NETWORK OVERVIEW CH : 15 LOCAL AREA NETWORK OVERVIEW P. 447 LAN (Local Area Network) A LAN consists of a shared transmission medium and a set of hardware and software for interfacing devices to the medium and regulating

More information

Unavoidable Constraints and Collision Avoidance Techniques in Performance Evaluation of Asynchronous Transmission WDMA Protocols

Unavoidable Constraints and Collision Avoidance Techniques in Performance Evaluation of Asynchronous Transmission WDMA Protocols 1th WEA International Conference on COMMUICATIO, Heraklion, reece, July 3-5, 8 Unavoidable Constraints and Collision Avoidance Techniques in Performance Evaluation of Asynchronous Transmission WDMA Protocols

More information

Teletraffic theory (for beginners)

Teletraffic theory (for beginners) Teletraffic theory (for beginners) samuli.aalto@hut.fi teletraf.ppt S-38.8 - The Principles of Telecommunications Technology - Fall 000 Contents Purpose of Teletraffic Theory Network level: switching principles

More information

Scheduling. Scheduling algorithms. Scheduling. Output buffered architecture. QoS scheduling algorithms. QoS-capable router

Scheduling. Scheduling algorithms. Scheduling. Output buffered architecture. QoS scheduling algorithms. QoS-capable router Scheduling algorithms Scheduling Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ Scheduling: choose a packet to transmit over a link among all

More information

Optical networking technology

Optical networking technology 1 Optical networking technology Technological advances in semiconductor products have essentially been the primary driver for the growth of networking that led to improvements and simplification in the

More information

Dynamic Routing and Wavelength Assignment Using First Policy Iteration

Dynamic Routing and Wavelength Assignment Using First Policy Iteration Dynamic Routing and Wavelength Assignment Using First Policy Iteration Esa Hyytiä and Jorma Virtamo Helsinki University of Technology Laboratory of Telecommunications Technology P.O.Box 3000, FIN-0 HUT,

More information

Copyright 2007 Pearson Addison-Wesley. All rights reserved. A. Levitin Introduction to the Design & Analysis of Algorithms, 2 nd ed., Ch.

Copyright 2007 Pearson Addison-Wesley. All rights reserved. A. Levitin Introduction to the Design & Analysis of Algorithms, 2 nd ed., Ch. Iterative Improvement Algorithm design technique for solving optimization problems Start with a feasible solution Repeat the following step until no improvement can be found: change the current feasible

More information

A novel method for QoS provisioning with protection in GMPLS networks

A novel method for QoS provisioning with protection in GMPLS networks Computer Communications 29 (2006) 757 764 www.elsevier.com/locate/comcom A novel method for QoS provisioning with protection in GMPLS networks Tricha Anjali a, *, Caterina Scoglio b,1 a Electrical and

More information

Intermediate-node-initiation (INI): A generalized signaling framework for optical burst-switched networks

Intermediate-node-initiation (INI): A generalized signaling framework for optical burst-switched networks Optical Switching and Networking 4 (2007) 20 32 www.elsevier.com/locate/osn Intermediate-node-initiation (INI): A generalized signaling framework for optical burst-switched networks Vinod M. Vokkarane

More information

Worst-case Ethernet Network Latency for Shaped Sources

Worst-case Ethernet Network Latency for Shaped Sources Worst-case Ethernet Network Latency for Shaped Sources Max Azarov, SMSC 7th October 2005 Contents For 802.3 ResE study group 1 Worst-case latency theorem 1 1.1 Assumptions.............................

More information

Graph Theoretic Models for Ad hoc Wireless Networks

Graph Theoretic Models for Ad hoc Wireless Networks Graph Theoretic Models for Ad hoc Wireless Networks Prof. Srikrishnan Divakaran DA-IICT 10/4/2009 DA-IICT 1 Talk Outline Overview of Ad hoc Networks Design Issues in Modeling Ad hoc Networks Graph Theoretic

More information

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING M.E., - COMMUNICATION SYSTEMS FIRST YEAR / FIRST SEMESTER - BATCH: 2014-2016 CU7103 OPTICAL NETWORKS 1 SYLLABUS CU7103 OPTICAL NETWORKS L T P C 3

More information

Traffic Analysis and Modeling of Real World Video Encoders

Traffic Analysis and Modeling of Real World Video Encoders Traffic Analysis and Modeling of Real World Video Encoders KLIMIS NTALIANIS, NIKOLAOS DOULAMIS, ANASTASIOS DOULAMIS AND STEFANOS KOLLIAS Department of Electrical and Computer Engineering National Technical

More information

An Ecient Approximation Algorithm for the. File Redistribution Scheduling Problem in. Fully Connected Networks. Abstract

An Ecient Approximation Algorithm for the. File Redistribution Scheduling Problem in. Fully Connected Networks. Abstract An Ecient Approximation Algorithm for the File Redistribution Scheduling Problem in Fully Connected Networks Ravi Varadarajan Pedro I. Rivera-Vega y Abstract We consider the problem of transferring a set

More information

SCHEDULING ALGORITHMS FOR UNICAST, MULTICAST, AND BROADCAST

SCHEDULING ALGORITHMS FOR UNICAST, MULTICAST, AND BROADCAST Chapter 1 SCHEDULING ALGORITHMS FOR UNICAST, MULTICAST, AND BROADCAST George N. Rouskas Department of Computer Science North Carolina State University Raleigh, NC 27695-7534 rouskas@csc.ncsu.edu Abstract

More information

Flexible Bandwidth Provisioning in WDM Networks by Fractional Lambda Switching

Flexible Bandwidth Provisioning in WDM Networks by Fractional Lambda Switching Flexible Bandwidth Provisioning in WDM Networks by Fractional Lambda Switching Achille Pattavina, Donato Grieco Politecnico di Milano, Milano, Italy e-mail: pattavina@elet.polimi.it Yoram Ofek Synchrodyne

More information

International Conference on Advances in Mechanical Engineering and Industrial Informatics (AMEII 2015)

International Conference on Advances in Mechanical Engineering and Industrial Informatics (AMEII 2015) International Conference on Advances in Mechanical Engineering and Industrial Informatics (AMEII 2015) A Cross Traffic Estimate Model for Optical Burst Switching Networks Yujue WANG 1, Dawei NIU 2, b,

More information

A 3-stage CLOS architecture for high-throughput optical packet switching

A 3-stage CLOS architecture for high-throughput optical packet switching Invited Paper A 3-stage CLOS architecture for high-throughput optical packet switching H.J.S. Dorren, Nicola Calabretta and Oded Raz COBRA Research Institute, Eindhoven University of Technology, P.O. Box

More information

A Comparison of Path Protections with Availability Concern in WDM Core Network

A Comparison of Path Protections with Availability Concern in WDM Core Network A Comparison of Path Protections with Availability Concern in WDM Core Network M. A. Farabi Photonic Technology Lab, Universiti Teknologi, S. M. Idrus Member, IEEE Photonic Technology Lab, Universiti Teknologi,

More information

ON THE COMPLEXITY OF THE BROADCAST SCHEDULING PROBLEM

ON THE COMPLEXITY OF THE BROADCAST SCHEDULING PROBLEM ON THE COMPLEXITY OF THE BROADCAST SCHEDULING PROBLEM SERGIY I. BUTENKO, CLAYTON W. COMMANDER, AND PANOS M. PARDALOS Abstract. In this paper, a Broadcast Scheduling Problem (bsp) in a time division multiple

More information

A Novel Approach to Reduce Packet Loss in OBS Networks

A Novel Approach to Reduce Packet Loss in OBS Networks A Novel Approach to Reduce Packet Loss in OBS Networks Amit Gupta 1, Harbhajan Singh 2, Jagdish Kumar 3 1 Deptt. of Electronics and Communication Engg, PTU, Jalandhar, India. 2 Deptt. of Electronics and

More information

Wavelength Reuse for Efficient Packet-Switched Transport in an AWG-Based Metro WDM Network

Wavelength Reuse for Efficient Packet-Switched Transport in an AWG-Based Metro WDM Network JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 21, NO. 6, JUNE 2003 1435 Wavelength Reuse for Efficient Packet-Switched Transport in an AWG-Based Metro WDM Network Michael Scheutzow, Martin Maier, Martin Reisslein,

More information