R. Doverspike

AT&T Labs, Austin, Texas, United States

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Publications (77)28.83 Total impact

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    ABSTRACT: We describe bandwidth-on-demand in an evolved multi-layer, SDN-based Cloud Services model. We also show an initial proof-of-concept demonstration of this capability.
    Optical Fiber Communication Conference; 03/2014
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    ABSTRACT: We summarize the DARPA CORONET program approach to bandwidth-on-demand, and implementation and demonstration of Cloud Computing applications in network testbeds.
    Optical Fiber Communication Conference; 03/2014
  • 12th INFORMS Telecommunications Conference, Lisbon, Portugal; 03/2014
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    ABSTRACT: Network planners are often requested to provision multiple physically-diverse high-speed circuits over a large carrier’s core (inter-city) DWDM network, which consists of multiple layers and heterogeneous vendor systems. Optimally provisioning such circuits while avoiding shared risk link group (SRLG) failures is an NP-hard problem. In this paper, we propose a novel and practical two-step approach: pre-processing with Integer Linear Programming (ILP) for absolutely or maximally SRLG-diverse routes and post-processing for DWDM system selection, regenerator placement and wavelength assignment. This approach has been implemented in a production network planning tool. According to our experiments, for a typical large carrier’s core optical network, most of the diverse-routing demands can be solved within 1 min, even with tens of thousands of binary decision variables, which allows interactive use by network planners.
    Computer Communications. 03/2013; 36(6):689–697.
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    ABSTRACT: The rapid advancement of smartphones has instigated tremendous data applications for cell phones. Supporting simultaneous voice and data services in a cellular network is not only desirable but also becoming indispensable. However, if the voice and data are serviced through the same antenna (like the 3G UMTS network), a voice call with data sessions requires better radio connection than a voice-only call. In this paper, we systematically study the coordination between the voice and data transmissions in UMTS networks. From analyzing a large carrier's UMTS network recording data, we first identify the most relevant network measurements/features indicating a potential call drop, then propose a drop-call predictor based on AdaBoost. Moreover, we develop an intelligent call management strategy to voluntarily block data sessions when the voice is predicted to be dropped. Our analysis utilizing real service provider's data sets shows that our proposed scheme can not only predict drop calls with a very high accuracy but also achieve the highest user satisfaction compared to the other existing call management strategies.
    INFOCOM, 2013 Proceedings IEEE; 01/2013
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    ABSTRACT: Advances in the development of colorless and nondirectional reconfigurable optical add-drop multiplexers (ROADMs) enable flexible predeployment of optoelectronic regenerators (reshaping, retiming, and reamplifying known as 3R) in future optical networks. Compared to the current practice of installing a regenerator only when a circuit needs them, predeployment of regenerators in specific sites will allow service providers to achieve rapid provisioning such as bandwidth-on-demand service and fast restoration. Concentrating the predeployment of regenerators in a subset of ROADM sites will achieve high utilization and reduces the network operational costs. We prove the resulting optimization problem is NP-hard and provide the proof. We present an efficient heuristic for this problem that takes into account both the cost of individual circuits (regenerator cost and transmission line system cost) and the number of regenerator sites. We validate our heuristic approach with integer linear programming (ILP) formulations for a small network. Using specific network examples, we show that our heuristic has near-optimal performance under most studied scenarios and cost models. We further enhance the heuristic to incorporate the probability of demand for each circuit. This enables a reduction in the number of regenerator sites by allowing circuits to use costlier paths if they have lower probability of being needed. We also evaluate the heuristic to determine the extra regenerator sites required to support diverse routing. In this paper, we provide detailed analysis, pseudocodes, and proofs for the models presented in our previous work [Nat. Fiber Optic Engineers Conf., 2012, NW3F.6; 9th Int. Conf. on Design of Reliable Communication Networks (DRCN), 2013, 139] and compare the heuristic results with ILP for a small-scale network topology.
    Journal of Optical Communications and Networking 01/2013; 5(11):1202-1214. · 1.43 Impact Factor
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    ABSTRACT: The advent of colorless and non-directional reconfigurable optical-add-drop multiplexers (ROADMs) will enable flexible pre-deployment of optoelectronic regenerators in future optical networks. Compared to the current practice of installing regenerators only when a circuit needs them, pre-deployment will allow service providers to achieve rapid provisioning and restoration. The pre-deployed regenerators should be concentrated in a selected subset of ROADM sites in order to attain high utilization and to reduce operational costs. We prove that the resulting optimization problem is NP-hard and present an efficient heuristic for this problem that takes into account both the cost of individual circuits (regenerator cost and transmission line system cost) and the probability of a given circuit request, as well as the number of regenerator sites. We provide various methods to reduce the number of regenerator sites, if low probability demands are allowed to have slightly costlier paths. Specific network examples show that the proposed heuristic has near optimal performance under most studied scenarios. We present results for several different cost models. We have also evaluated the heuristic for survivable optical networks, in which a second, disjoint path must be supported for each circuit. An extended version of this paper containing proofs, pseudo-codes and additional experimental results is available online [1].
    Design of Reliable Communication Networks (DRCN), 2013 9th International Conference on the; 01/2013
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    ABSTRACT: this paper takes a closer look at the shared risk link group (SRLG) optimization issue and proposes algorithm on how to reduce the size of the SRLGs for different applications with correctness proofs.
    Journal of Optical Communications and Networking 03/2012; 4(11). · 1.43 Impact Factor
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    ABSTRACT: We describe the multi-layer GRIPhoN architecture which provides dynamic bandwidth at the OTN and wavelength layers for private-line customers. We propose and demonstrate an automated restoration approach for wavelength connections using dynamic re-provisioning.
    03/2012;
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    ABSTRACT: We describe the multi-layer GRIPhoN architecture which provides dynamic bandwidth at the OTN and wavelength layers for private-line customers. We propose and demonstrate an automated restoration approach for wavelength connections using dynamic re-provisioning.
    Optical Fiber Communication Conference and Exposition (OFC/NFOEC), 2012 and the National Fiber Optic Engineers Conference; 01/2012
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    ABSTRACT: The Core Optical Networks (CORONET) program addresses the development of architectures, protocols, and network control and management to support the future advanced requirements of both commercial and government networks, with a focus on highly dynamic and highly resilient multi-terabit core networks. CORONET encompasses a global network supporting a combination of IP and wavelength services. Satisfying the aggressive requirements of the program required a comprehensive approach addressing connection setup, restoration, quality of service, network design, and nodal architecture. This paper addresses the major innovations developed in Phase 1 of the program by the team led by Telcordia and AT&T. The ultimate goal is to transfer the technology to commercial and government networks for deployment in the next few years.
    Journal of Optical Communications and Networking. 12/2011; 4(1):1-14.
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    ABSTRACT: Cloud service providers use replication across geographically distributed data centers to improve end-to-end performance as well as to offer high reliability under failures. Content replication often involves the transfer of huge data sets over the wide area network and demands high backbone transport capacity. In this paper, we discuss how a Globally Reconfigurable Intelligent Photonic Network (GRIPhoN) between data centers could improve operational flexibility for cloud service providers. The proposed GRIPhoN architecture is an extension of earlier work [34] and can provide a bandwidth-on-demand service ranging from low data rates (e.g., 1 Gbps) to high data rates (e.g., 10-40 Gbps). The inter-data center communication network which is currently statically provisioned could be dynamically configured based on demand. Today's backbone optical networks can take several weeks to provision a customer's private line connection. GRIPhoN would enable cloud operators to dynamically set up and tear down their connections (sub-wavelength or wavelength rates) within a few minutes. GRIPhoN also offers cost-effective restoration capabilities at wavelength rates and automated bridge-and-roll of private line connections to minimize the impact of planned maintenance activities.
    11/2011;
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    ABSTRACT: Currently, there is no existing solution or tool to efficiently route a high-speed circuit over heterogeneous DWDM networks under multi-vendor environment, although each vendor may provide a planning tool to route a circuit within its own sub-network domain. This is mainly due to the lack of common technology for optical reachability calculation across vendor sub-networks. Each sub-network has its own proprietary parameters or formulas to calculate whether an optical path is reachable or not. To route a circuit across heterogeneous networks, we rely on the common function provided by each vendor tool to determine all reachable paths within each sub-network, i.e, the reachability matrix for each sub-network. Here reachability matrix is defined as a list of all reachable paths within the sub-network. Then we build a weighted cost graph based on the reachability matrices and apply the shortest path algorithm to find a cost efficient route. Finally we address the DWDM (Dense Wavelength Division Multiplex) sub-network selection, regenerator placement, and wavelength assignment on the selected route. The systematical methodology has been implemented in a circuit planning tool for high-speed circuits (up to 100Gbps) and used in a real heterogeneous DWDM network since 2009.
    Computer Communications Workshops (INFOCOM WKSHPS), 2011 IEEE Conference on; 05/2011
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    A. Gerber, R. Doverspike
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    ABSTRACT: We review the growth of the different sources of data traffic on backbones, highlight the importance and nature of IP services today, and discuss the implications on content distribution and efficient use of backbone capacity.
    Optical Fiber Communication Conference and Exposition (OFC/NFOEC), 2011 and the National Fiber Optic Engineers Conference; 04/2011
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    ABSTRACT: We propose a novel graph model for multiplexing optimization in optical networks and evaluate the performance of several multiplexing policies. Simulation shows that our advocated multiplexing policy can provide significant network cost savings.
    03/2011;
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    Kostas N. Oikonomou, Rakesh K. Sinha, Robert D. Doverspike
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    ABSTRACT: We outline a network design technique that exploits differences in the failure rate and impact of network elements to produce a more efficient design. We demonstrate its efficacy on a Tier-1 backbone network. © 2010 Optical Society of America OCIS codes: 060.4254, 060.4261
    03/2011;
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    ABSTRACT: Today's networks typically handle traffic engineering (e.g., tuning the routing-protocol parameters to optimize the flow of traffic) and failure recovery (e.g., pre-installed backup paths) independently. In this paper, we propose a unified way to balance load efficiently under a wide range of failure scenarios. Our architecture supports flexible splitting of traffic over multiple precomputed paths, with efficient path-level failure detection and automatic load balancing over the remaining paths. We propose two candidate solutions that differ in how the routers rebalance the load after a failure, leading to a trade-off between router complexity and load-balancing performance. We present and solve the optimization problems that compute the configuration state for each router. Our experiments with traffic measurements and topology data (including shared risks in the underlying transport network) from a large ISP identify a "sweet spot" that achieves near-optimal load balancing under a variety of failure scenarios, with a relatively small amount of state in the routers. We believe that our solution for joint traffic engineering and failure recovery will appeal to Internet Service Providers as well as the operators of data-center networks.
    SIGMETRICS 2011, Proceedings of the 2011 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems, San Jose, CA, USA, 07-11 June 2011 (Co-located with FCRC 2011); 01/2011
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    ABSTRACT: Network planners are often requested to provision multiple physically-diverse high-speed circuits over a large carrier's core (inter-city) DWDM network, which consists of multiple layers and heterogeneous vendor systems. Optimally provisioning such circuits while avoiding shared risk link group (SRLG) failures is an NP-hard problem. In this paper, we propose a novel hybrid two-step approach: pre-processing with Integer Linear Programming (ILP) for diverse routing and postprocessing for regenerator placement and wavelength assignment. This approach has been implemented in a prototype network planning tool. According to our experiments, most of the cases for a typical large carrier's core transport network can be solved within 1 minute, even with tens of thousands of binary decision variables, which allows interactive use by network planners.
    8th International Workshop on the Design of Reliable Communication Networks, DRCN 2011, Krakow, Poland, 10-12 October, 2011; 01/2011
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    ABSTRACT: We describe an architecture solution for performing cost-effective circuit routing over multi-vendor heterogeneous DWDM networks, including building blocks, data flow, reachability matrix generation, cost model, diversity, regenerator and wavelength assignments.
    01/2011;
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    ABSTRACT: With increasing demands for dynamic high data-rate private line services from large customers, network carriers have begun to provide flexible on-demand connections to construct these customers' networks. Advances in optical devices have greatly improved the reconfigurability of the optical layer, which makes it possible to provide optical on-demand services at wavelength granularity (10 Gbps to 40 Gbps per channel). This new dynamic wavelength service model allows a customer owning or leasing a few terminal ports in the network to connect these ports on demand. The network must be pre-dimensioned with enough resources to support any possible connection configuration between the pre allocated ports of a dynamic wavelength customer. In this paper, we introduce a resource optimization problem for dynamic wave length services and propose a few efficient techniques to tackle this challenging problem. A heuristic optimizer based on a combination of simulated annealing and genetic algorithms is developed to solve the problem efficiently for large networks. We show that our solver can produce optimization solutions within 7% overhead of a lower bound with a small amount of computation.
    Journal of Lightwave Technology 01/2011; 29(5):756-769. · 2.56 Impact Factor

Publication Stats

636 Citations
28.83 Total Impact Points

Institutions

  • 2001–2011
    • AT&T Labs
      Austin, Texas, United States
  • 2010
    • University of Illinois, Urbana-Champaign
      • Department of Electrical and Computer Engineering
      Urbana, IL, United States
  • 2008
    • University of Nevada, Reno
      Reno, Nevada, United States