Optimization methods for topological design of interconnected ring networks

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 177-179).by Valery Brodsky.M.S

Hierarchical Ring Network Design Using Branch-and-Price

Abstract. We consider the problem of designing hierarchical two layer ring networks. The top layer consists of a federal-ring which establishes connection between a number of node disjoint metro-rings in a bottom layer. The objective is to minimize the costs of links in the network, taking both the fixed link establishment costs and the link capacity costs into account. Hierarchical ring network design problems combines the following optimization problems: Clustering, hub selection, metro ring design, federal ring design and routing problems. In this paper a branch-and-price algorithm is presented for jointly solving the clustering problem, the metro ring design problem and the routing problem. Computational results are given for networks with up to 36 nodes

Optimization in Telecommunication Networks

Network design and network synthesis have been the classical optimization problems intelecommunication for a long time. In the recent past, there have been many technologicaldevelopments such as digitization of information, optical networks, internet, and wirelessnetworks. These developments have led to a series of new optimization problems. Thismanuscript gives an overview of the developments in solving both classical and moderntelecom optimization problems.We start with a short historical overview of the technological developments. Then,the classical (still actual) network design and synthesis problems are described with anemphasis on the latest developments on modelling and solving them. Classical results suchas Menger’s disjoint paths theorem, and Ford-Fulkerson’s max-flow-min-cut theorem, butalso Gomory-Hu trees and the Okamura-Seymour cut-condition, will be related to themodels described. Finally, we describe recent optimization problems such as routing andwavelength assignment, and grooming in optical networks.operations research and management science;

Resilient network design: Challenges and future directions

This paper highlights the complexity and challenges of providing reliable services in the evolving communications infrastructure. The hurdles in providing end-to-end availability guarantees are discussed and research problems identified. Avenues for overcoming some of the challenges examined are presented. This includes the use of a highly available network spine embedded in a physical network together with efficient crosslayer mapping to offer survivability and differentiation of traffic into classes of resilience. © 2013 Springer Science+Business Media New York

The ring/κ-rings network design problem: Model and branch-and-cut algorithm

This article considers the problem of designing a two-level network where the upper level consists of a backbone ring network connecting the so-called hub nodes, and the lower level is formed by access ring networks that connect the non-hub nodes to the hub nodes. There is a fixed cost for each type of link, and a facility opening cost associated to each hub. The number of nodes in each access ring is bounded, and the number of access rings connected to a hub is limited to κ, thus resulting in a ring/κ-rings topology. The aim is to decide the hubs to open and to design the backbone and access rings to minimize the installation cost. We propose a mathematical model, give valid inequalities, and describe a branch-and-cut algorithm to solve the problem. Computational results show the algorithm is able to find optimal solutions on instances involving up to 40 nodes within a reasonable time. © 2016 Wiley Periodicals, Inc. NETWORKS, Vol. 68(2), 130–140 2016. © 2016 Wiley Periodicals, Inc

Spare capacity allocation using partially disjoint paths for dual link failure protection

A shared backup path protection (SBPP) scheme can be used to protect dual link failures by pre-planning each traffic flow with mutually disjoint working and two backup paths while minimizing the network overbuild. However, many existing backbone networks are bi-connected without three fully disjoint paths between all node pairs. Hence in practice partially disjoint paths (PDP) have been used for backup paths instead of fully disjoint ones. This paper studies the minimum spare capacity allocation (SCA) problem using PDP within an optimization framework. This is an extension of the spare provision matrix (SPM) method for PDP. The integer linear programming (ILP) model is formulated and an approximation algorithm, Successive Survivable Routing (SSR), is extended and used in the numerical study. © 2013 Scientific Assoc for infocom

Protection architectures for multi-wavelength optical networks.

by Lee Chi Man.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 63-65).Abstracts in English and Chinese.Chapter CHAPTER 1 --- INTRODUCTION --- p.5Chapter 1.1 --- Background --- p.5Chapter 1.1.1 --- Backbone network - Long haul mesh network problem --- p.5Chapter 1.1.2 --- Access network ´ؤ Last mile problems --- p.8Chapter 1.1.3 --- Network integration --- p.9Chapter 1.2 --- SUMMARY OF INSIGHTS --- p.10Chapter 1.3 --- Contribution of this thesis --- p.11Chapter 1.4 --- Structure of the thesis --- p.11Chapter CHAPTER 2 --- PREVIOUS PROTECTION ARCHITECTURES --- p.12Chapter 2.1 --- Introduction --- p.12Chapter 2.2 --- Traditional physical protection architectures in metro area --- p.13Chapter 2.2.1 --- Self healing ring --- p.17Chapter 2.2.2 --- Some terminology in ring protection --- p.13Chapter 2.2.3 --- Unidirectional path-switched rings (UPSR) [17] --- p.13Chapter 2.2.4 --- Bidirectional line-switched rings (BLSR) [17] --- p.14Chapter 2.2.5 --- Ring interconnection and dual homing [17] --- p.16Chapter 2.3 --- Traditional physical protection architectures in access networks --- p.17Chapter 2.3.1 --- Basic architecture in passive optical networks --- p.17Chapter 2.3.2 --- Fault management issue in access networks --- p.18Chapter 2.3.3 --- Some protection architectures --- p.18Chapter 2.4 --- Recent protection architectures on a ccess networks --- p.21Chapter 2.4.1 --- Star-Ring-Bus architecture --- p.21Chapter 2.5 --- Concluding remarks --- p.22Chapter CHAPTER 3 --- GROUP PROTECTION ARCHITECTURE (GPA) FOR TRAFFIC RESTORATION IN MULTI- WAVELENGTH PASSIVE OPTICAL NETWORKS --- p.23Chapter 3.1 --- Background --- p.23Chapter 3.2 --- Organization of Chapter 3 --- p.24Chapter 3.3 --- Overview of Group Protection Architecture --- p.24Chapter 3.3.1 --- Network architecture --- p.24Chapter 3.3.2 --- Wavelength assignment --- p.25Chapter 3.3.3 --- Normal operation of the scheme --- p.25Chapter 3.3.4 --- Protection mechanism --- p.26Chapter 3.4 --- Enhanced GPA architecture --- p.27Chapter 3.4.1 --- Network architecture --- p.27Chapter 3.4.2 --- Wavelength assignment --- p.28Chapter 3.4.3 --- Realization of network elements --- p.28Chapter 3.4.3.1 --- Optical line terminal (OLT) --- p.28Chapter 3.4.3.2 --- Remote node (RN) --- p.29Chapter 3.4.3.3 --- Realization of optical network unit (ONU) --- p.30Chapter 3.4.4 --- Protection switching and restoration --- p.31Chapter 3.4.5 --- Experimental demonstration --- p.31Chapter 3.5 --- Conclusion --- p.33Chapter CHAPTER 4 --- A NOVEL CONE PROTECTION ARCHITECTURE (CPA) SCHEME FOR WDM PASSIVE OPTICAL ACCESS NETWORKS --- p.35Chapter 4.1 --- Introduction --- p.35Chapter 4.2 --- Single-side Cone Protection Architecture (SS-CPA) --- p.36Chapter 4.2.1 --- Network topology of SS-CPA --- p.36Chapter 4.2.2 --- Wavelength assignment of SS-CPA --- p.36Chapter 4.2.3 --- Realization of remote node --- p.37Chapter 4.2.4 --- Realization of optical network unit --- p.39Chapter 4.2.5 --- Two types of failures --- p.40Chapter 4.2.6 --- Protection mechanism against failure --- p.40Chapter 4.2.6.1 --- Multi-failures of type I failure --- p.40Chapter 4.2.6.2 --- Type II failure --- p.40Chapter 4.2.7 --- Experimental demonstration --- p.41Chapter 4.2.8 --- Power budget --- p.42Chapter 4.2.9 --- Protection capability analysis --- p.42Chapter 4.2.10 --- Non-fully-connected case and its extensibility for addition --- p.42Chapter 4.2.11 --- Scalability --- p.43Chapter 4.2.12 --- Summary --- p.43Chapter 4.3 --- Comparison between GPA and SS-CPA scheme --- p.43Chapter 4.1 --- Resources comparison --- p.43Chapter 4.2 --- Protection capability comparison --- p.44Chapter 4.4 --- Concluding remarks --- p.45Chapter CHAPTER 5 --- MUL 77- WA VELENGTH MUL TICAST NETWORK IN PASSIVE OPTICAL NETWORK --- p.46Chapter 5.1 --- Introduction --- p.46Chapter 5.2 --- Organization of this chapter --- p.47Chapter 5.3 --- Simple Group Multicast Network (SGMN) scheme --- p.47Chapter 5.3.1 --- Network design principle --- p.47Chapter 5.3.2 --- Wavelength assignment of SGMN --- p.48Chapter 5.3.3 --- Realization of remote node --- p.49Chapter 5.3.3 --- Realization of optical network unit --- p.50Chapter 5.3.4 --- Power budget --- p.51Chapter 5.4 --- A mulTI- wa velength a ccess network with reconfigurable multicast …… --- p.51Chapter 5.4.1 --- Motivation --- p.51Chapter 5.4.2 --- Background --- p.51Chapter 5.4.3 --- Network design principle --- p.52Chapter 5.4.4 --- Wavelength assignment --- p.52Chapter 5.4.5 --- Remote Node design --- p.53Chapter 5.4.6 --- Optical network unit design --- p.54Chapter 5.4.7 --- Multicast connection pattern --- p.55Chapter 5.4.8 --- Multicast group selection in OLT --- p.57Chapter 5.4.9 --- Scalability --- p.57Chapter 5.4.10 --- Experimental configuration --- p.58Chapter 5.4.11 --- Concluding remarks --- p.59Chapter CHAPTER 6 --- CONCLUSIONS --- p.60LIST OF PUBLICATIONS: --- p.62REFERENCES: --- p.6

Dynamic Virtual Network Restoration with Optimal Standby Virtual Router Selection

Title form PDF of title page, viewed on September 4, 2015Dissertation advisor: Deep MedhiVitaIncludes bibliographic references (pages 141-157)Thesis (Ph.D.)--School of Computing and Engineering and Department of Mathematics and Statistics. University of Missouri--Kansas City, 2015Network virtualization technologies allow service providers to request partitioned, QoS guaranteed and fault-tolerant virtual networks provisioned by the substrate network provider (i.e., physical infrastructure provider). A virtualized networking environment (VNE) has common features such as partition, flexibility, etc., but fault-tolerance requires additional efforts to provide survivability against failures on either virtual networks or the substrate network. Two common survivability paradigms are protection (proactive) and restoration (reactive). In the protection scheme, the substrate network provider (SNP) allocates redundant resources (e.g., nodes, paths, bandwidths, etc) to protect against potential failures in the VNE. In the restoration scheme, the SNP dynamically allocates resources to restore the networks, and it usually occurs after the failure is detected. In this dissertation, we design a restoration scheme that can be dynamically implemented in a centralized manner by an SNP to achieve survivability against node failures in the VNE. The proposed restoration scheme is designed to be integrated with a protection scheme, where the SNP allocates spare virtual routers (VRs) as standbys for the virtual networks (VN) and they are ready to serve in the restoration scheme after a node failure has been identified. These standby virtual routers (S-VR) are reserved as a sharedbackup for any single node failure, and during the restoration procedure, one of the S-VR will be selected to replace the failed VR. In this work, we present an optimal S-VR selection approach to simultaneously restore multiple VNs affected by failed VRs, where these VRs may be affected by failures within themselves or at their substrate host (i.e., power outage, hardware failures, maintenance, etc.). Furthermore, the restoration scheme is embedded into a dynamic reconfiguration scheme (DRS), so that the affected VNs can be dynamically restored by a centralized virtual network manager (VNM). We first introduce a dynamic reconfiguration scheme (DRS) against node failures in a VNE, and then present an experimental study by implementing this DRS over a realistic VNE using GpENI testbed. For this experimental study, we ran the DRS to restore one VN with a single-VR failure, and the results showed that with a proper S-VR selection, the performance of the affected VN could be well restored. Next, we proposed an Mixed-Integer Linear Programming (MILP) model with dual–goals to optimally select S-VRs to restore all VNs affected by VR failures while load balancing. We also present a heuristic algorithm based on the model. By considering a number of factors, we present numerical studies to show how the optimal selection is affected. The results show that the proposed heuristic’s performance is close to the optimization model when there were sufficient standby virtual routers for each virtual network and the substrate nodes have the capability to support multiple standby virtual routers to be in service simultaneously. Finally, we present the design of a software-defined resilient VNE with the optimal S-VR selection model, and discuss a prototype implementation on the GENI testbed.Introduction -- Literature survey -- Dynamic reconfiguration scheme in a VNE -- An experimental study on GpENI-VNI -- Optimal standby virtual router selection model -- Prototype design and implementation on GENI -- Conclusion and future work -- Appendix A. Resource Specification (RSpec) in GENI -- Appendix B. Optimal S-VR Selection Model in AMP