1,095 research outputs found
Software Defined Networks based Smart Grid Communication: A Comprehensive Survey
The current power grid is no longer a feasible solution due to
ever-increasing user demand of electricity, old infrastructure, and reliability
issues and thus require transformation to a better grid a.k.a., smart grid
(SG). The key features that distinguish SG from the conventional electrical
power grid are its capability to perform two-way communication, demand side
management, and real time pricing. Despite all these advantages that SG will
bring, there are certain issues which are specific to SG communication system.
For instance, network management of current SG systems is complex, time
consuming, and done manually. Moreover, SG communication (SGC) system is built
on different vendor specific devices and protocols. Therefore, the current SG
systems are not protocol independent, thus leading to interoperability issue.
Software defined network (SDN) has been proposed to monitor and manage the
communication networks globally. This article serves as a comprehensive survey
on SDN-based SGC. In this article, we first discuss taxonomy of advantages of
SDNbased SGC.We then discuss SDN-based SGC architectures, along with case
studies. Our article provides an in-depth discussion on routing schemes for
SDN-based SGC. We also provide detailed survey of security and privacy schemes
applied to SDN-based SGC. We furthermore present challenges, open issues, and
future research directions related to SDN-based SGC.Comment: Accepte
Advancement of Monitoring Scheme in FTTH-PON Using Access Control System (ACS)
This paper proposes a new developed system named Access Control System (ACS) which is designed to enhance the monitoring, scalability and survivability of Passive Optical Network (PON) toward the implementation of full & Complete edition of Fiber-to-the Network (FTTH) network. The system automatically identifies faults and controls each optical fiber line to provide the restoration against failure in the drop region of PON downwardly from optical line terminal at the central office to the optical network unit of the subscriber. ACS manages the Optical Time Domain Reflectometer (OTDR) troubleshooting wavelength to enable the status of each line which can be displayed onto one single screen in the central office. Our proposed mechanism in this paper is the first reported thus far. Keywords: ACS, monitoring, path routing, experimental, FTTH-PO
Design a MATLAB-based system architecture for locating fiber fault in optical access network
This paper experimentally demonstrated a MATLAB-based graphical user interface (GUI) named Smart Access Network _Testing, Analyzing and Database (SANTAD) that able to measure the optical signal level, attenuation, losses, as well as detect any occurrence of fault and address the failure location in optical access network with point-to-multipoint (P2MP) configuration.This paper also presented a restoration mechanism scheme, where the protection mechanism for tree based optical switch will have capability to divert the signal
onto protection line according to the types of failure condition and location of failures in access network.This will ensure the data flow continuously due to breakdown occur in the network
and instantly repair the operation.The restoration scheme was simulated using OptiSystem, Inc. software in order to prove the solution feasibility
SDN based testbeds for evaluating and promoting multipath TCP
Multipath TCP is an experimental transport proto-
col with remarkable recent past and non-negligible future poten-
tial. It has been standardized recently, however the evaluation
studies focus only on a limited set of isolated use-cases and
a comprehensive analysis or a feasible path of Internet-wide
adoption is still missing. This is mostly because in the current
networking practice it is unusual to configure multiple paths
between the endpoints of a connection. Therefore, conducting and
precisely controlling multipath experiments over the real “inter-
net” is a challenging task for some experimenters and impossible
for others. In this paper, we invoke SDN technology to make
this control possible and exploit large-scale internet testbeds to
conduct end-to-end MPTCP experiments. More specifically, we
establish a special purpose control and measurement framework
on top of two distinct internet testbeds. First, using the OpenFlow
support of GÉANT, we build a testbed enabling measurements
with real traffic. Second, we design and establish a publicly
available large-scale multipath capable measurement framework
on top of PlanetLab Europe and show the challenges of such
a system. Furthermore, we present measurements results with
MPTCP in both testbeds to get insight into its behavior in such
not well explored environment
Design and implementation of the OFELIA FP7 facility: The European OpenFlow testbed
The growth of the Internet in terms of number of devices, the number of networks associated to each device and the mobility of devices and users makes the operation and management of the Internet network infrastructure a very complex challenge. In order to address this challenge, innovative solutions and ideas must be tested and evaluated in real network environments and not only based on simulations or laboratory setups.
OFELIA is an European FP7 project and its main objective is to address the aforementioned challenge by building and operating a multi-layer, multi-technology and geographically distributed Future Internet testbed facility, where the network itself is precisely controlled and programmed by the experimenter using the emerging OpenFlow technology. This paper reports on the work done during the first half of the project, the lessons learned as well as the key advantages of the OFELIA facility for developing and testing new networking ideas.
An overview on the challenges that have been faced on the design and implementation of the testbed facility is described, including the OFELIA Control Framework testbed management software. In addition, early operational experience of the facility since it was opened to the general public, providing five different testbeds or islands, is described
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
Fast WDM provisioning with minimal probing: the first field experiments for DC exchanges
We propose an approach to estimate the end-to-end GSNR accurately in a short
time when a data center interconnect (DCI) network operator receives a service
request from users, not by measuring the GSNR at the operational route and
wavelength for the End-End optical path but by simply applying a QoT probe
channel link by link, at a convenient wavelength/modulation-format for
measurement. Assuming connections between coherent transceivers of various
frequency ranges, modulators, and modulation formats, we propose a new device
software architecture in which the DCI network operator optimizes the
transmission mode between user transceivers with high accuracy using only
standard parameters such as Bit Error Rate. In this paper, we first
experimentally built three different routes of 32 km/72 km/122 km in the C-band
to confirm the accuracy of this approach. For the operational end-to-end GSNR
measurements, the accuracy estimated from the sum of the measurements for each
link was 0.6 dB, and the wavelength-dependent error was about 0.2 dB. Then,
using field fibers deployed in the NSF COSMOS testbed (deployed in an urban
area), a Linux-based transmission device software architecture, and coherent
transceivers with different optical frequency ranges, modulators, and
modulation formats, the fast WDM provisioning of an optical path was completed
within 6 minutes (with a Q-factor error of about 0.7 dB).Comment: 9 pages, 11 figures, 3 table
- …