Martin Lévesque

In this paper, we discuss the communications reliability requirements posed by the smart power grid with a focus on communications in support of wide area situational awareness. Implementation of wide area situational awareness relies on both transmission substation networks and wide area optical networks.
We study the reliability of a sample communications network of the California Power Grid and find that its reliability falls short of proposed requirements. To overcome this issue, we consider the problem of designing the network to meet the reliability requirements while minimizing the network cost.
Therefore, we propose two greedy iterative heuristics and a heuristic integer linear programming (H-ILP) model using minimum cut-sets for network reliability optimization. The greedy iterative algorithms outperform the H-ILP approach in terms of cost, but require a larger amount of computing resources. Both proposed models are in fact complementary and thus provide a framework to optimize the reliability of smart grid communications networks.

In this paper, we study the performance of multitier
integrated fiber-wireless (FiWi) smart grid communications
infrastructures based on low-cost, simple, and reliable nextgeneration
passive optical network (PON) with quality-of-service
(QoS) enabled wireless local area networks (WLANs) in terms
of capacity, latency, and reliability. We study the coexistence of
human-to-human (H2H), e.g., triple-play traffic, and machineto-
machine (M2M) traffic originating from wireless sensors
operating on a wide range of possible configurations. Our analysis
enables the quantification of the maximum achievable data
rates of both event- and time-driven wireless sensors without
violating given upper delay limits of H2H traffic. By using
experimental measurements of real-world smart grid applications
we investigate the impact of variable H2H traffic loads on the
sensor end-to-end delay performance. The obtained results show
that a conventional Ethernet PON may cause a bottleneck and
increase the delay for both H2H and M2M traffic. In contrast, by
using a 10G-EPON or wavelength division multiplexing (WDM)
PON the bottleneck arises in the wireless network. Furthermore,
we study the interplay between time- and event-driven nodes and
show that the theoretical upper bound of time-driven sensors
decreases linearly as a function of the number of sensors, while
with event-driven sensors the upper bound decrease is nonlinear
and more pronounced.

Availability is one of the most important quality
attributes for smart grid communications, as qualitatively defined
in the IEEE P2030 standard. However, the availability metric
must be quantified in order to validate given smart grid application
requirements. In recent related work, availability has
been quantified for wireless and optical backhaul networks in
terms of communications reachability, while in some other work
availability was not formally defined in a fine-grained manner
and was assumed to be known. In this paper, we develop a
novel multi-class probabilistic availability model for integrated
passive optical network (PON) and WiMAX networks in order to
quantify this metric according to medium access control (MAC)
protocol limits as well as fiber and base station failures. The
obtained numeric results show interesting availability behaviors,
including the impact on availability depending on the number
of base stations. We also investigate optical traffic re-routing
through WiMAX when fiber faults occur and show that there
exists a maximum amount of re-routed traffic for maximizing
availability. Furthermore, we investigate a scenario of real-world
smart grid traffic configurations shared with regular traffic and
find the maximum sensor data rate to meet the availability
requirements.

The smart grid is an improved power system of the 20th century characterized essentially by a two-way flow of energy and information. In that sense, the smart grid is sometimes called Energy Internet, where actors and components exchange energy and data with each other, similarly to the Internet where components and actors exchange data over a shared infrastructure. Many wired and wireless communications technologies could be used for smart grid communications. According to IEEE P2030, the three main quality attributes for robust smart grid communications are latency, reliability, and quality of service. Communications latency between a given pair of source and destination nodes is expressed as the time when the message is generated and the time when it is received at the reception side. Reliability is formally defined as the ability to perform a certain task for given conditions during a certain period of time. According to Telecom Italia, the current trend in the access networks is the convergence of fiber-to- the-home (FTTH) for their durability, reliability, and energy efficiency. China Telecom deployed over 70 millions FTTH ports between 2004 and 2012. Furthermore, China Telecom predicts that the major upcoming trends are: (i) increase of fiber penetration (ii) more capacity and speed, from 1 Gbps passive optical networks (PONs) towards 40 Gbps in a single PON system and (iii) increase of the coverage by integrating wired, wireless, and mobile nodes. According to China Telecom, PONs will converge into fiber-wireless (FiWi) networks to combine their respective advantages. Optical networks offer huge capacity, immunity against electromagnetic interference, and wireless networks can be deployed quickly at a low cost and offer mobility. FiWi networks can also be enriched by integrating optical and wireless sensors. Such networks can use fiber Bragg grating optical-based sensors and wireless sensors compliant with IEEE 802.15.4 ZigBee. Integrating sensors allow to interact with real-world systems to monitor different parameters, including temperature, pressure, sound, etc. This is a great opportunity for the telecommunications and many economic sect ors , that is, sharing low-cost access networks for improved efficiency and sustainability. In the following, we quant if y the performance of emerging FiWi access networks and propose new mechanisms by means of probabilistic analyses. Such probabilistic analyses allow to quickly quantify the communications performance for large topologies. In smart grid solutions, innovative partnerships hold great promise to enable utilities and other players to share smart grid communications infrastructures investments by transitioning from the traditional vertical network integration model towards splitting the value chain into multi-tier business models.

FiWi networks can not only exchange video, voice, and data as in any broadband access
networks, but can also be enriched with fiber or wireless sensors to lead to novel fiber-wireless access
sensors networks for supporting smart grid applications. Currently, available sensor data rates might not
be enough to fully monitor power grid elements. On the other hand, sending measurements by using a
high data rate might heavily utilize network resources, whereby consecutive measurements might have
similar values. Since such access networks influence not only the communications architecture, but also
the electric grid, we developed a novel co-simulator that enables us to measure both communications and
power network perspectives to verify emerging smart grid applications such as the coordination of plug-in
electric vehicles. We proposed an integrated vehicle-to-grid, grid-to-vehicle, and renewable energy source
algorithm to decrease the peak demand without compromising on user preferences.

The new Smart Grid communications architecture
for the distribution power grid and customers needs to be reliable,
effective in terms of delay, and secure. To manage reliability
and latency, a novel adaptive admission control algorithm is
defined for a recently proposed Smart Grid FiWi communications
infrastructure. To show one of the benefits of the proposed
admission control algorithm, a scenario of power blackouts
during a security breach is performed with an experimental
FiWi network testbed. Results show that the proposed admission
control algorithm effectively controls latency and reliability in
the event of power blackouts, even under a DDoS attack.

In the future, communications networks are expected to become less an end itself than a means to an end by
exploiting them not only for telecommunications per se but also across other relevant economic sectors in order
to reap larger benefits from interdisciplinary research across traditional borders, e.g., an increased overall
reduction of greenhouse gas emissions across multiple sectors such as energy and transportation, as envisioned
by the future Smart Grid. The two main quality attributes of a Smart Grid communications infrastructure are
reliability and latency, as defined in IEEE P2030. This paper proposes to aggregate triple-play and Smart Grid
services into a converged fiber-wireless (FiWi) broadband access network based on low cost Ethernet passive
optical network (EPON) and wireless mesh networks. We first show that, as the load of the FiWi network
increases, performance degradation in terms of packet drop and latency of Smart Grid applications occurs due to
the lack of quality-of-service (QoS) protection. To mitigate this problem, we propose an adaptive admission
control algorithm to provide QoS support for FiWi Smart Grid communications networks. Simulation results
show that the proposed admission control enables QoS guarantees for triple-play applications as well as future
Smart Grid applications over the same FiWi infrastructure.

—To cope with the unprecedented growth of mobile data traffic, we investigate the performance gains obtained from unifying coverage-centric 4G mobile networks and capacity-centric fiber-wireless (FiWi) broadband access networks based on data-centric Ethernet technologies with resulting fiber backhaul sharing and WiFi offloading capabilities. Despite recent progress on backhaul-aware 4G studies with capacity-limited backhaul links, the performance-limiting impact of backhaul latency and reliability has not been examined in sufficient detail previously. In this paper, we evaluate the maximum aggregate throughput, offloading efficiency, and in particular the delay performance of FiWi enhanced LTE-A heterogeneous networks (HetNets), including the beneficial impact of various localized fiber-lean backhaul redundancy and wireless protection techniques, by means of probabilistic analysis and verifying simulation, paying close attention to fiber backhaul reliability issues and WiFi offloading limitations due to WiFi mesh node failures as well as temporal and spatial WiFi coverage constraints. We use recent and comprehensive smartphone traces of the PhoneLab dataset to verify whether the previously reported assumption that the complementary cumulative distribution function (CCDF) of both WiFi connection and interconnection times fit a truncated Pareto distribution is still valid. In our study, we put a particular focus on the 5G key attributes of very low latency and ultra-high reliability and investigate how they can be achieved in FiWi enhanced LTE-A HetNets. Furthermore, given the growing interest in decentralization of future 5G networks (e.g., user equipment assisted mobility) we develop a decentralized routing algorithm for FiWi enhanced LTE-A HetNets.

To cope with the unprecedented growth of mobile
data traffic, we investigate the performance gains obtained from unifying coverage-centric 4G mobile networks and capacitycentric fiber-wireless (FiWi) broadband access networks based on data-centric Ethernet technologies with resulting fiber backhaul sharing and WiFi offloading capabilities. Despite recent progress on backhaul-aware 4G studies with capacity-limited backhaul links, the performance-limiting impact of backhaul latency and reliability has not been examined in sufficient detail previously. In this paper, we evaluate the maximum aggregate throughput, offloading efficiency, and in particular the delay performance of FiWi enhanced LTE-A heterogeneous networks (HetNets), including the beneficial impact of various localized fiber-lean backhaul redundancy and wireless protection techniques, by means of probabilistic analysis and verifying simulation, paying close attention to fiber backhaul reliability issues and WiFi offloading limitations due to WiFi mesh node failures as well as temporal and spatial WiFi coverage constraints.

Current Gigabit-class passive optical networks
(PONs) evolve into next-generation PONs, whereby high-speed
10+ Gb/s time division multiplexing (TDM) and long-reach
wavelength-broadcasting/routing wavelength division multiplexing
(WDM) PONs are promising near-term candidates. On
the other hand, next-generation wireless local area networks
(WLANs) based on frame aggregation techniques will leverage
physical layer enhancements, giving rise to Gigabit-class very
high throughput (VHT) WLANs. In this paper, we develop
an analytical framework for evaluating the capacity and delay
performance of a wide range of routing algorithms in converged
fiber-wireless (FiWi) broadband access networks based
on different next-generation PONs and a Gigabit-class multiradio
multi-channel WLAN-mesh front-end. Our framework is
very flexible and incorporates arbitrary frame size distributions,
traffic matrices, optical/wireless propagation delays, data rates,
and fiber faults. We verify the accuracy of our probabilistic
analysis by means of simulation for the wireless and wirelessoptical-
wireless operation modes of various FiWi network architectures
under peer-to-peer, upstream, uniform, and nonuniform
traffic scenarios. The results indicate that our proposed optimized
FiWi routing algorithm (OFRA) outperforms minimum (wireless)
hop and delay routing in terms of throughput for balanced and
unbalanced traffic loads, at the expense of a slightly increased
mean delay at small to medium traffic loads.

Toward the vision of complete fixed-mobile convergence,
a plethora of wireless, integrated optical-wireless, multipath,
and energy-aware routing algorithms were proposed for
legacy EPON/WLAN-mesh based bimodal fiber-wireless (FiWi)
broadband access networks. In this paper, we present the
first comprehensive analytical framework for providing deeper
insights into the capacity and delay performance of routing
algorithms in next-generation FiWi networks based on emerging
powerful optical and wireless technologies such as long-reach 10+
Gb/s TDM/WDM PONs and Gigabit-class VHT WLANs.

This paper reviews the main thrusts in next-generation passive optical network (NG-PON) 1 and 2 technologies that enable short-term evolutionary and long-term revolutionary upgrades of co-existent Gigabit-class PONs, respectively. It provides insight into the key requirements and challenges of the major candidate NG-PON 1&2 architectures such as long-reach XG-PON, wavelength-routing WDM PON, OCDMA and OFDMA PON, and reports on recent progress toward enhanced data and control plane functionalities, including real-time dynamic bandwidth allocation, improved privacy and guaranteed QoS, bandwidth flexibility, as well as cost-effective in service monitoring techniques for NG-PONs. We then elaborate on converged optical fiber-wireless (FiWi) access networks, which may be viewed as the endgame of broadband access, and explain the inherent coverage and QoS issues of conventional radio-over-fiber (RoF) networks for distributed wireless medium access control (MAC) protocols and how their limitations can be avoided in so-called radio-and-fiber (R&F) networks. We explore powerful layer-2 optical-wireless, hierarchical frame aggregation, and network coding techniques that significantly improve the throughput-delay performance, resource utilization efficiency, and survivability of NG-PON and FiWi networks. Finally, we inquire into the opportunities of sensor-enhanced FiWi networks and propose our novel Über-FiWi network, whose potential is demonstrated by studying the beneficial impact of inter-home scheduling of emerging plug-in electric vehicles (PEVs) on the resource management of a more sustainable future smart grid.

According to the Organisation for Economic Co-operation and Development (OECD), broadband access networks
enable the emergence of new business models, processes, inventions, as well as improved goods and
services. In fact, broadband access is viewed as a so-called general purpose technology (GPT) that has the
potential to fundamentally change how and where economic activity is organized. In this paper, we focus on
the implications of the emerging Third Industrial Revolution (TIR) economy, which goes well beyond current
austerity measures, and has recently been officially endorsed by the European Commission as the economic growth
roadmap toward a competitive low carbon society by 2050. This roadmap has been receiving an increasing amount
of attention by other key players, e.g., the Government of China most recently. More specifically, we describe
a variety of advanced techniques to render converged bimodal fiber-wireless (FiWi) broadband access networks
dependable, including optical coding based fiber fault monitoring techniques, localized optical redundancy strategies,
wireless extensions, and availability-aware routing algorithms, to improve their reliability, availability, survivability,
security, and safety. Next, we elaborate on how the resultant dependent FiWi access networks can be exploited to enhance the dependability of other critical infrastructures of our society, most notably the future smart power
grid and its envisioned electric transportation, by means of probabilistic analysis, co-simulation, and experimental
demonstration.

Multiple simulation tools have been built and studied independently
in the communications and power system perspectives
of IEEE P2030 to study new Smart Grid applications.
However, very few studies have been done on co-simulation
by combining both perspectives in a multidiciplinary manner.
In this paper, we show implementation details of our
novel communications and power distribution network cosimulator
based on OMNeT++ and OpenDSS. We then
demonstrate the novelty of our co-simulator by showing the
impact of data rate-based and event-based sensors on reactive
control algorithms of plug-in electric vehicles to reduce
critical voltage durations.

In this paper, a multi-simulation model is proposed to measure the performance of all Smart Grid perspectives
as defined in the IEEE P2030 standard. As a preliminary implementation, a novel information technology (IT) and
communication multi-simulator is developed following an High Level Architecture (HLA). To illustrate the usefulness
of such a multi-simulator, a case study of a distribution network operation application is presented using real-world
topology configurations with realistic communication traffic based on IEC 61850. The multi-simulator allows to
quantify, in terms of communication delay and system reliability, the impacts of aggregating all traffic on a low-
capacity wireless link based on Digital Mobile Radio (DMR) when a Long Term Evolution (LTE) network failure
occurs. The case study illustrates that such a multi-simulator can be used to experiment new smart grid mechanisms and
verify their impacts on all smart grid perspectives in an automated manner. Even more importantly, multi-simulation
can prevent problems before modifying/upgrading a smart grid and thus potentially reduce costs to the utility.

Microgrids have been proposed as a key piece of the Smart Grid vision to enable the potential of renewable energy generation. Microgrids are required to operate in both grid connected and standalone island mode using local sources of power. A major challenge in implementing microgrids is the communications and control to support transition to and from grid connected mode and operation in island mode. Microgrids consists of two interdependent networks, namely; the power distribution and data communication networks. To accurately capture the overall operation of the system, we propose a co-simulation model driven by embedded power controllers. Further, we propose a novel co-simulation scheduler taking into account events from both the power and communication network simulators, as well as the timing of each embedded controller’s execution loop to adaptively synchronize both simulators efficiently. The approach ensures minimal synchronization error while still providing the ability to simulate extended operational scenarios. The numerical results illustrate the novelty of the propose co-simulation to study the microgrid power and communication networks interactions, and the effect on the power stability.

Plug-in electric vehicles (PEVs) have great potential
of being the alternative for the next-generation of transportation.
Uncoordinated PEV charging, however, may put a significant
pressure on the distribution grid. In this paper, on a modified
IEEE-13 Node distribution network of 342 residential customers,
we propose a converged fiber-wireless infrastructure based on
EPON, WiMAX, wireless mesh network and sensor technologies
to support coordinated charging of PEVs. To measure the
performance of both the communications and power system
perspectives of proactive scheduling algorithms and proposed
reactive control protocols, our recently developed hybrid cosimulator
based on OMNeT++ and OpenDSS is used. Cosimulation
results show that the proposed low-cost communications
infrastructure enables to efficiently schedule PEV chargings
and quickly stabilize the voltage in a stress scenario.

High penetration of renewable energy sources and
electric vehicles (EVs) creates power imbalance and congestion
in the existing power network and hence causes significant
problems in the control and operation. Despite investing huge
efforts from the electric utilities, governments, and researchers,
smart grid (SG) is still at the developmental stage to address
those issues. In this regard, a smart grid testbed (SGT) is
desirable to develop, analyze, and demonstrate various novel SG
solutions, namely demand response (DR), real-time pricing, and
congestion management. In this work, a novel SGT is developed
in a laboratory by scaling a 250 kVA, 0.4 kV real low voltage
distribution feeder down to 1 kVA, 0.22 kV. Information and
communication technology (ICT) is integrated in the scaleddown
network to establish real-time monitoring and control. The
novelty of the developed testbed is demonstrated by optimizing
EV charging coordination realized through the synchronized
exchange of monitoring and control packets via an heterogeneous
Ethernet-based mesh network.

It is of great importance to smart grids to build a communications network that can support the future power
utility growth, customer connections, and new applications. Relying on advanced communications and
broadband access technologies, power utilities are moving towards distribution grid modernization to optimize
energy utilization. One significant main concern is the integration of plug-in electric vehicles (PEVs) within
smart grids. This chapter provides a comprehensive performance evaluation of PEV coordination strategies over
integrated Fiber-Wireless (FiWi) smart grid communications infrastructures using a scaled-down testbed and
advanced co-simulator. As the coordination of PEVs was not experimentally demonstrated previously, we
describe our smart grid testbed based on a real-world distribution network in Denmark by scaling a 250 kVA,
0.4 kV real low-voltage distribution feeder down to 1 kVA, 0.22 kV. We first describe the architecture of the
power and communications networks, the scaling-down process, and its main functionalities. Furthermore, we
propose and demonstrate a novel centralized PEV scheduling and decentralized coordination mechanism. The
obtained experimental results show that the proposed hybrid centralized and decentralized control approach for
PEV charging simultaneously takes into account the charging cost, network congestion, and local voltage.
Moreover, the coordination between distribution management system (DMS) and sensors is realized in real-time
using our developed smart grid testbed (SGT) by the synchronized exchange of power and control signals via a
heterogeneous Ethernet-based mesh network. The developed SGT is a step forward to (i) identify practical
problems and (ii) validate and test new smart grid mechanisms under realistic physical conditions. However,
building such a testbed is time and space consuming. To evaluate large-scale smart grid systems, co- and multisimulation
experiments may be carried out instead. Therefore, we next study the co-simulation of a power
distribution system combined with a smart grid communications infrastructure in order to enable real-time
exchange of information between PEVs and utilities for the coordination of charging algorithms, which allow
PEVs to intelligently consume or send stored power back to the grid (Vehicle-To-Grid capability). We
implement different types of coordinated PEV charging algorithms in a multidisciplinary approach by means of
co-simulation of both power and communication perspectives. We compare the performance of both centralized
and decentralized PEV charging algorithms in terms of power and communication metrics. We also investigate
on the integration of photovoltaic solar panels to locally charge PEVs, which plays a major role in limiting the
impact of PEV charging on the utility grid and thereby minimizing peak energy demand as well as effectively
achieving load balancing.

In this paper, an integrated vehicle-to-grid, grid-tovehicle,
and renewable energy sources (IntVGR) coordination
algorithm is proposed. The focus of this work is to provide a
multidisciplinary study on implementing the proposed IntVGR
scheme over a broadband fiber-wireless communications infrastructure
by co-simulating both power and communications
perspectives. For the power systems perspective, results show that
the scheme is able to achieve a 21% reduction in peak demand
compared to uncontrolled charging, and a better performance in
flattening the overall demand profile and maintaining network
constraints in comparison to a benchmark scenario. The scheme
has also been demonstrated to successfully coordinate PEVs to
take maximum utilization of local renewable energy. For the
communications perspective, the measured upstream traffic for
executing the proposed IntVGR scheme on a residential area
of 342 households is found to be 1-2 Mbps with an end-to-end
latency level of 1 ms. The scheme has also been validated from
both perspectives in a sensitivity analysis with a higher PEV
adoption rate.

Clock synchronization is a prerequisite for the realization of emerging applications in various domains such as industrial automation and the intelligent power grid. This paper surveys the standardized protocols and technologies for providing synchronization of devices connected by packet-switched networks. A review of synchronization impairments and the state-of-the-art mechanisms to improve the synchronization accuracy is then presented. Providing microsecond to sub-microsecond synchronization accuracy under the presence of asymmetric delays in a cost-effective manner is a challenging problem, and still an open issue in many application scenarios. Further, security is of significant importance for systems where timing is critical. The security threats and solutions to protect exchanged synchronization messages are also discussed.

Tight synchronization timing is expected to play a crucial role for the realization of emerging Internet of Things (IoT) high value real-time applications such as smart transportation and smart grid. Most packet-based synchronization protocols require two-way communications delay symmetry for precise accuracy. The Precision Time Protocol (PTP) provides mechanisms to measure and take into account the delay asymmetry problem, such as the residence time measurements, but recommend  PTP support at all nodes. In this paper, we consider partial on-path PTP support, where a subset of the nodes are PTP unaware. We propose probing-based mechanisms in order to estimate asymmetry and improve the synchronization performance. The extensive simulation results show that the proposed lightweight per-packet asymmetry mitigation (PPAM) mechanism, aiming at estimating the per-packet delay components, outperforms the other considered protocols mainly at low to mid network loads, while under certain conditions the regular PTP with QoS support provides more stable synchronization accuracy.

Precise time synchronization is expected to play a key role in emerging distributed and real-time applications such as the smart grid and Internet of Things (IoT) based applications. The Precision Time Protocol (PTP) is currently viewed as one of the main synchronization solutions over a packet-switched network, which supports microsecond synchronization accuracy. In this paper, we present a PTP simulation model for OMNeT++ INET, which allows to investigate the synchronization accuracy under different network configurations and conditions. To show some illustrative simulation results using the developed module, we investigate on the network load fluctuations and their impacts on the PTP performance by considering a network with class-based quality-of-service (QoS) support. The simulation results show that the network load significantly affects the network delay symmetry, and investigate a new technique called class probing to improve the PTP accuracy and mitigate the load fluctuation effects.

L'explosion actuelle de l'utilisation des applications en temps reel, telles que la telephonie
et la video haute denition, fait en sorte qu'une demande croissante en bande passante
existe. Or, la bre optique ore un tres grand potentiel en termes de bande passante allant
physiquement jusqu'a 50 terabits par seconde par bre optique en utilisant un multiplexage
en longueurs d'onde. La commutation de rafales en optique est une nouvelle technique de
commutation permettant de tirer prot des avantages de la commutation de paquets et de
la commutation de circuits. Une problematique majeure est le taux de perte eleve a cause
du probleme de la contention. Plusieurs techniques de resolution de la contention existent,
notamment la de
exion et la retransmission.
Dans la premiere partie de ce travail, on s'interesse a combiner dynamiquement la de
exion
et la retransmission d'une maniere adaptative en tenant compte de l'etat du reseau. L'algorithme
propose permet d'eectuer le plus de de
exions possibles tant que celles-ci ne
destabilisent pas le reseau. Les resultats demontrent egalement, avec des topologies fortement
connectees telles que COST239, que l'algorithme propose permet de diminuer radicalement
les pertes en utilisant un ratio de de
exion tres grand.
La deuxieme partie de ce travail porte sur la prevention de la contention en utilisant des
tables de routage optimisees. Ces tables de routage sont optimisees en utilisant un modele
graphique probabiliste utilise en intelligence articielle, soit un reseau bayesien.

Burst contention is a well-known challenging problem in
Optical Burst Switching (OBS) networks. Deflection routing is used to
resolve contention. Burst retransmission is used to reduce the Burst Loss
Ratio (BLR) by retransmitting dropped bursts. Previous works show that
combining deflection and retransmission outperforms both pure deflection
and pure retransmission approaches. This paper proposes a new Adaptive
Hybrid Deflection and Retransmission (AHDR) approach that dynamically
combines deflection and retransmission approaches based on network
conditions such as BLR and link utilization. Network Simulator 2 (ns-2) is
used to simulate the proposed approach on different network topologies.
Simulation results show that the proposed approach outperforms static
approaches in terms of BLR by using an adaptive decision threshold.

Burst contention is a well known challenging problem in
Optical Burst Switching (OBS) networks. Deflection routing is used to
resolve contention. Burst retransmission is used to reduce the Burst Loss
Ratio (BLR) by retransmitting dropped bursts. Previous works show that
combining deflection and retransmission outperforms both pure deflection
and pure retransmission approaches. This paper proposes a new Adaptive
Hybrid Deflection and Retransmission (AHDR) approach that dynamically
combines deflection and retransmission approaches based on network
conditions such as BLR and link utilization. Network Simulator 2 (ns-2) is
used to simulate the proposed approach on different network topologies.
Simulation results show that the proposed approach outperforms static
approaches in terms of BLR and goodput.

Burst contention is a well-known challenging problem in Optical
Burst Switching (OBS) networks. Contention resolution approaches
are always reactive and attempt to minimize the BLR based on local
information available at the core node. On the other hand, a proactive
approach that avoids burst losses before they occur is desirable. To reduce
the probability of burst contention, a more robust routing algorithm
than the shortest path is needed. This paper proposes a new routing
mechanism for JET-based OBS networks, called Graphical Probabilistic
Routing Model (GPRM) that selects less utilized links, on a hop-by-hop
basis by using a bayesian network. We assume no wavelength conversion
and no buffering to be available at the core nodes of the OBS network.We
simulate the proposed approach under dynamic load to demonstrate that
it reduces the Burst Loss Ratio (BLR) compared to static approaches by
using Network Simulator 2 (ns-2) on NSFnet network topology and with
realistic traffic matrix. Simulation results clearly show that the proposed
approach outperforms static approaches in terms of BLR.

Workshop on Fiber-Wireless (FiWi) Access Networks

The Workshop on Fiber-Wireless (FiWi) Access Networks will be held in conjunction with the 15th edition of the IEEE International Conference on Ubiquitous Wireless Broadband ICUWB’2015 in Montreal, Canada, from October 4th to 7th, 2015 (http://www.icuwb2015.org/index.html).

Prospective authors are invited to submit technical papers of their previously unpublished work on EDAS at (http://edas.info/N20805). Manuscripts shall not exceed five double-column pages. Complete information about the electronic paper submission process is available at (http://www.icuwb2015.org/papers-submissions.html). All accepted and presented papers will be submitted for inclusion in IEEE Xplore®.

Mobile network operators and service providers are faced with the prospect of mobile data delivery costs outweighing revenues. In their quest for a ubiquitous ultra-high bandwidth communication infrastructure towards 5G, the backhaul is becoming a major performance-limiting factor and thus a pressing concern in mobile networks. In the past, most 4G LTE network research has been focusing on the achievable performance gains in the wireless front-end only without looking into the details of backhaul implementations and possible backhaul bottlenecks. It is only recently that backhaul-aware 4G studies have begun to take capacity-limited backhaul links, as found in many of today’s existing systems, into account and investigated the performance- limiting impact and details of different backhaul technologies.

To cope with the unprecedented growth of mobile data traffic driven by the popularity of smart phones and mobile-connected tablets running diverse data- centric applications, the removal of the traditional barriers between coverage-centric 4G mobile networks and capacity-centric fiber-wireless (FiWi) broadband access networks based on low-cost data-centric Ethernet technologies represents one of several promising approaches to benefit from fiber backhaul sharing and WiFi offloading capabilities in unified cellular and FiWi broadband access networks.

Topics of interest include but are not limited to the following:

• Backhaul awareness
• Cloud radio access network
• Computation offloading
• Decentralization
• Gigabit-class wireless front-end
• Heterogeneous networks
• Infrastructure sharing
• Integration of fiber optic and wireless sensors • Low-latency networking techniques
• Mobile cloud computing
• Mobile data offloading
• Network architectures
• Network planning and reconfiguration
• Networked robotics
• New business models
• Next-generation optical access solutions
• Optical and wireless protection
• Optical-wireless integration
• Next-Generation PONs
• Radio-over-fiber networks
• Reliable network connectivity
• Routing and QoS continuity
• Smart grid/city applications
• Techno-economic analysis
• User equipment assisted mobility
• WiFi offloading
• Wireless backhaul

WORKSHOP ORGANIZER AND CHAIR

Martin Maier
INRS, EMT Center


IMPORTANT DUE DATES

Workshop submissions: July 31, 2015
Workshop decisions: August 14, 2015
Camera-ready submissions: August 21, 2015
Author registration: August 21, 2015

The Hypertext Transfer Protocol (HTTP), a key building block of the World Wide Web, has succeeded to enable information exchange worldwide. Since its first version in 1996, HTTP/1.0, the average number of inlined objects and average total bytes per webpage have been increasing significantly for desktops and mobiles, from 1-10 objects in 1996 to more than 100 objects in June 2014. Even if the retrieving of inlined objects can be parallelized as a given Hypertext Markup Language (HTML) document is streamed, a maximum number of connections is allocated, and thus as the number of inlined objects increases, the overall webpage load duration grows, and the HTTP servers loading also gets higher. To overcome this issue, we propose a new HTTP method called BURST, which allows to retrieve the missing inlined objects of a webpage efficiently by requesting sets of web objects. We experimentally demonstrate the potential via a proof-of-concept demonstration, by comparing the regular HTTP to proposed HTTP-Burst using a virtual private server and real HTTP client and server over the Internet. The results indicate a latency reduction of webpage load duration compared to HTTP as high as 52 % under the considered configurations.