Recent advances in the areas of Internet of Things (IoT), big data, and machine learning have contributed to the rise of a growing number of complex applications. These applications will be data-intensive, delay-sensitive, and real-time as smart devices prevail more in our daily life. Ensuring quality of service (QoS) for delay-sensitive applications is a must, and fog computing is seen as one of the primary enablers for satisfying such tight QoS requirements, as it puts compute, storage, and networking resources closer to the user. In this paper, we first introduce FOGPLAN, a framework for QoS-aware dynamic fog service provisioning (QDFSP). QDFSP concerns the dynamic deployment of application services on fog nodes, or the release of application services that have previously been deployed on fog nodes, in order to meet low latency and QoS requirements of applications while minimizing cost. FOGPLAN framework is practical and operates with no assumptions and minimal information about IoT nodes. Next, we present a possible formulation (as an optimization problem) and two efficient greedy algorithms for addressing the QDFSP at one instance of time. Finally, the FOGPLAN framework is evaluated using a simulation based on real-world traffic traces.

In this paper, we address the issue of survivability in statistically shared elastic optical networks. Statistical sharing in elastic optical networks is motivated by the recent revolution of software defined optics, where variable data rates, e.g., base rates and peak rates, are supported for a single connection in the network. Our goal is to minimize the blocking of the arriving connection requests, while at the same time maximizing the chance that existing connection requests are able to switch from base rate to peak rate. Furthermore, the base rate of the connection requests should be survivable to any single link failure. In this paper, we introduce an admission control policy and a spectrum management technique that specifies how the spectrum is partitioned and shared for base rate connections, peak rate connections, and back- up capacity. We then propose several survivability schemes in order to provide dedicated protection to the base rate of the connection requests. We evaluate our proposed schemes through simulations, seeking to find an optimum tradeoff between the base rate and the peak rate blocking.

Network function virtualization (NFV) provides an efficient and flexible way to deploy network services in the form of service function chains (SFCs) by adopting generalized equipment. However, software-based virtualized network functions (VNFs) bring new challenge for network operators in providing service availability guarantees. Traditionally, network-level protection mechanisms are considered separately from function-level VNF backup mechanisms. However, a SFC's availability cannot be guaranteed if only network- level protection mechanisms or only function-level VNF backup mechanisms are considered. In this paper, we propose a coordinated protection mechanism that adopts both backup path protection in the network and VNF replicas at nodes to guarantee a SFC's availability. The proposed mechanism determines the number of replicas required for each VNF in the SFC, and allocates the replicas to physical nodes on the working and backup paths while maintaining ordered dependency among VNFs. Simulation results show that the proposed algorithms contribute to reducing the SFC blocking and the cost of computing resources.

We consider virtual optical network (VON) mapping with the objective of minimizing total network link cost while guaranteeing VON availability, where VON availability is supported by providing shared backup path protection for selected VON links. We develop a matrix-based approach for calculating the availability of a VON mapping with shared backup path protection. In order to efficiently evaluate the maximum availability of a VON mapping, we transform the problem to a group node-weighted Steiner tree problem and propose an efficient auxiliary-graph-based availability (AA) algorithm to find a VON mapping with high availability. Based on the availability evaluation, we propose a heuristic algorithm to map the VON, and numerical results show that our algorithms are effective in achieving high availability while reducing the total link cost and the blocking rate.

We consider virtual optical network (VON) provisioning over a flexible-grid multi-domain optical network with the objective of minimizing total network cost, including the cost of transponders, regenerators, and spectrum. We propose a three-step heuristic algorithm that addresses the issues of domain selection, topology aggregation, and routing, modulation format, and spectrum assignment (RMSA) when mapping virtual optical links onto multi-domain physical optical links. We propose a domain selection technique that attempts to minimize the number of inter- domain virtual optical links. We then suggest a topology aggregation (TA) technique to exchange intra and inter-domain information between domains, and propose a method for RMSA over the aggregated topology. Numerical results show that our heuristic approach is effective in reducing total network cost.

In this paper, we study a new optical network paradigm, where statistical sharing is supported in optical networks. This new paradigm is motivated by the recent revolution of Software Defined Optics (SDO). Software defined variable-bandwidth transponders can support variable data rates for a single connection, i.e. base rates and peak rates. Guaranteeing the peak rates for all the connections simultaneously requires the spectrum for all circuits to be provisioned for peak rates, leading to a large amount of bandwidth usage with low utilization. However, if resources are provisioned for the base rate of each connection, with some shared spectrum resources set aside to allow a fraction of these connections to dynamically switch to their peak rates, then spectrum resources can be allocated more efficiently, allowing a greater number of connections to be accommodated. We reserve a fraction of the spectrum resources for provisioning of base rate of the dynamic traffic while the rest of the spectrum resources are reserved for peak rate, allowing statistical sharing. Our goal is to minimize the blocking of the arriving connection requests, while at the same time maximizing the chance that existing connection requests are able to switch from base rate to peak rate. These two goals conflict with each other; therefore, we need to find a trade-off based on the amount of spectrum resources set aside for the peak rate, and based on the routing, modulation format selection, and spectrum allocation (RMSA) scheme. Our evaluation can help network operators to determine the amount of spectrum that requires to be set aside for peak rates in order to maximize revenue.

In this paper, we consider the problem of routing, modulation, and spectrum assignment (RMSA) for data- flow transfers in elastic optical networks. We design a two-dimensional resource model, in which each data transfer with known data size can be assigned a rectangular block of resources that spans both the spectrum and time dimensions. Furthermore, the dynamic spectral resource allocation problem in elastic optical networks is simplified to the two-dimensional rectangle packing problem. We design a three-tuple for each rectangle placement, and develop a dynamic heuristic algorithm, Best Rectangle Fit (BRF), to efficiently schedule requests while minimizing fragmentation in both spectrum and time domains. We simulate the proposed algorithm, and the results show that the proposed RMSA algorithm (BRF) can greatly decrease blocking probability and increase spectrum utilization.

In this paper, we study a new paradigm in optical networking in which optical spectrum is allowed to be statistically shared between optical circuits, allowing the oversubscription of optical links. We propose a probabilistic model which estimates the capacity requirements for the optical networks under a certain density of statistical sharing. Simulation results indicate that our proposed model can help with network design decisions, such as admission control and capacity and bandwidth allocation in elastic optical networks.

In this paper, we consider the problem of routing, modulation, and spectrum assignment (RMSA) for immediate and advance reservation requests in elastic optical networks. We design a two-dimensional resource model for maintaining resource state information in both spectrum and time domains. For the purpose of minimizing the blocking probability and increasing spectrum utilization, we develop a two phase RMSA algorithm that attempts to decrease spectrum resource fragmentation by scheduling the requests in a manner that takes into account the holding time of each request. We design a simulation to evaluate the performance of the proposed algorithm, and the experiment results show that our proposed two phase RMSA algorithm can greatly reduce blocking probability and obtain high spectrum utilization.

We consider the problem of efficient virtual optical network (VON) mapping in a multi-domain optical network (VON-MD) with the objective of minimizing total network link cost for a given VON demand that is embedded over the multi-domain optical network. Topology aggregation (TA) is used to exchange intra and inter-domain information between domains, and heuristic algorithms are proposed for embedding considering different domain selection techniques and virtual link ordering techniques. We provide an integer linear programming formulation (ILP-VON-MD) to compare with our heuristic approaches. Numerical results show that our heuristic approaches are effective in reducing total network cost.

Customer churn is a big concern for telecom service providers due to its associated costs. This short paper briefly explains our ongoing work on customer churn prediction for telecom services. We are working on data mining methods to accurately predict customers who will change and turn to another provider for the same or similar service. Sample dataset we use for our experiments has been compiled by Orange Telecom from real data. They posted the sample dataset for 2009 Knowledge Discovery and Data Mining Competition. IBM has scored the highest on this dataset requiring significant amount of computational resources. We are aiming to find alternative methods that can match or improve the recorded highest score with more efficient use of resources. Dataset has very large number of features, examples and incomplete values. As the first step, we employ some methods to preprocess the dataset for its imperfections. Then, we compare and contrast various ensemble and single classifiers. We conclude the paper with future directions for the study.

In a multi-domain network, domains can be defined geographically or administratively. Since only a limited amount of information of each domain is allowed to be broadcasted by domain service providers, Topology Aggregation (TA) is usually adopted. The amount of information provided by each domain may vary based on the service provider. For instance, some domains may provide only a single shortest path between two border nodes, while others may be capable of providing a pair of disjoint paths with minimum total cost. In this case, inter-domain path routing with protection needs to consider and utilize the different levels of information provided by different domains in order to find the best solution. In this paper, we propose two approaches that find a pair of disjoint inter-domain paths with minimum total cost based on a matrix for each domain that includes disjointness information between the aggregated links inside the domain.

Abstract This paper presents a method for the composition of at-location with other semantic relations. The method is based on inference axioms that combine two semantic relations yielding another relation that otherwise is not expressed. An experimental study conducted on PropBank, WordNet, and eXtended WordNet shows that inferences have high accuracy. The method is applicable to combining other semantic relations and it is beneficial to many semantically intense applications.

In this paper, we address the problem of survivable traffic grooming and regenerator placement in optical WDM networks with impairment constraints. The working connections are protected end to end by provisioning bandwidth along a sequence of lightpaths through a dedicated connection-level protection scheme. An auxiliary-graph-based approach is proposed to address the placement of regenerators and grooming equipment for both working and dedicated backup connections in the network with the goal of minimizing the total equipment cost. Simulation results show that the proposed algorithm outperforms a lightpath-level protection algorithm, in which each lightpath is protected separately. We also show the effect of different cost models on equipment placement and evaluate the performance for networks with different line rates.

This paper presents a semiautomatic method for generating commonsense axioms. The method relies on three metarules that process a few commonsense rules referring to some concept properties. The proposed algorithm searches automatically in Extended WordNet for all concepts that have a given property and generates axioms linking those concepts with the seed commonsense rule. The results show that using 27 commonsense rules, the algorithm generated 2596 axioms of which 98% were validated by human. The generation of commonsense axioms is useful to many natural language applications that require reasoning.

Carriers determined to stay competitive in the market have learned that simply going for the cheapest networking solution in terms of CAPEX is not enough, as the total cost includes OPEX as well. Availability of the network, which is too important to ignore in terms of providing meaningful service to customers, also relates to OPEX cost through maintenance and repair efforts. This study introduces a modeling methodology that incorporates availability awareness in to the cost modeling in order to propose a mesh architecture for a given core network with an acceptable trade-off between cost-efficiency and availability.

Existing burst scheduling techniques could be improved in terms of bandwidth utilization and QoS support. In this paper, we introduced a new partially preemptive scheduling technique with QoS support. The technique is capable of handling data bursts in parts and may use preemption due to the priorities of data bursts in a multi-service OBS network environment. Simulation studies suggest that more than 50% reduction in dropping probability and approximately 40% improvement in channel utilization is reachable at 0.8 load. The studies also reveal that the new scheduling technique has the ability to predict and control service performance differentiation among defined service classes.

To date, all of the proposals for burst-scheduling techniques have considered scheduling individual bursts. We introduce a new scheme called OBS group scheduling. In this approach, a burst is represented by an interval of time. The process of scheduling a number of bursts, thus, turns to be a process of fitting a set of the corresponding time intervals on a channel time line that represents a channel-time resource. By doing so, we can formulate the scheduling process as a combinatorial optimization problem. Then, graph theory is applied to schedule as many non-overlapping intervals as possible onto the channel time line. The underlying concept of the group scheduling is that of briefly delaying the scheduling of a burst so that a much better decision can be made about a number of bursts all-together. This scheme is shown, through simulations, to improve performance in terms of burst loss probability and channel utilization over existing schemes.

This paper studies the performance of TCP transport protocol over an optical burst-switched (OBS) wavelength division multiplexed (WDM) wide-area network. Typically, an OBS network consists of optical core routers and electronic edge routers connected by WDM links. At the network ingress nodes, IP packets are assembled into bursts that are routed through the core network and disassembled at the network egress nodes. This paper studies the effects of OBS network characteristics and parameters on TCP's delay and throughput performance: (i) burstification (burst-assembly and disassembly) delays, (ii) data-burst scheduling and (iii) variation of burst packet parameters (i.e. burst size, burst time-outs), and (iv) burst drop probability. Detailed results based on an ns2-based simulator, that has been extended to incorporate WDM and OBS networking, are presented.

In this paper, we study several multicast schemes in optical burst-switched WDM networks taking into consideration of the overheads due to control packets and guard bands (GBs) of bursts on separate channels (wavelengths). A straightforward scheme is called separate multicasting (S-MCAST) where each source node constructs separate bursts for its multicast (per each multicast session) and unicast traffic. To reduce the overhead due to GBs (and control packets), one may piggyback the multicast traffic in bursts containing unicast traffic using a scheme called multiple unicasting (M-UCAST). The third scheme is called tree-shared multicasting (TS-MCAST) whereby multicast traffic belonging to multiple multicast sessions can be mixed together in a burst, which is delivered via a shared multicast tree. The multicast schemes (M-UCAST and TS-MCAST) are compared with S-MCAST in terms of bandwidth consumed and processing load.

Optical burst switching (OBS) is a promising solution for building terabit optical routers and realizing IP over WDM. In this paper, we describe the basic concept of OBS and present a general architecture of optical core routers and electronic edge routers in the OBS network. The key design issues related to the OBS are also discussed, namely, burst assembly (burstification), channel scheduling, burst offset-time management, and some dimensioning rules. A nonperiodic time-interval burst assembly mechanism is described. A class of data channel scheduling algorithms with void filling is proposed for optical routers using a fiber delay line buffer. The LAUC-VF (latest available unused channel with void filling) channel scheduling algorithm is studied in detail. Initial results on the burst traffic characteristics and on the performance of optical routers in the OBS network with self-similar traffic as inputs are reported in the paper.

This paper describes a graphical user interface propelled by a simulation engine for performance analysis of a channel assignment model for high-volume cellular networks. It also discusses some experimental results.

The performance evaluation of large self-healing SONET mesh networks is of great interest to the telecom industry. In this paper, we first modify a model that has been proposed originally for the reliability analysis of SONET networks, for the performance evaluation of such networks. Then, we propose a hierarchical approach that will not only reduce the complexity of the analysis, but also improve the accuracy. The sensitivity of the performance metrics to the traffic distribution and the performance of individual subnetworks are studied experimentally.

Recently, a parametric State Reward Markov Model (SRMM/p) has been developed for the reliability and availability analysis of self-healing SONET mesh networks [2]. In this paper, we investigate the factors that affect the run-time complexity of the model presented in [2]. In order to accelerate the reliability and availability analysis, we present an approach that aggregates a set of states in the model based on 2-phase hypoexponential distribution. A comparison of the original and the reduced model, with respect to runtime complexity and accuracy, is carried out by applying the models for the analysis of few complex networks.