Mantis: Optical network planning and operation tool

Mantis: Cloud-based optical network planning and operation tool

Elastic optical network (EON) is a promising candidate for the next generation optical transport network because of its high spectrum efficiency and flexible spectrum allocation. However, to migrate from today’s dense wavelength division multiplexing (DWDM) network to EON, optical nodes such as reconfigurable optical add/drop multiplexers (ROADMs) should be replaced with the ones with expensive flexi-grid wavelength selective switches (WSSs). Thus, whether and how today’s optical network will be evolved to EON is still under debate. Meanwhile, with the technical maturity of optical super-channels that transmit bit rates at the level of 1 Tb/s, super-channels are expected to dominate the future optical transport network because of their attractiveness of high spectrum efficiency and superior cost effectiveness. In this paper, we propose a new quasi-coarse wavelength division multiplexing (Quasi-CWDM) optical network architecture that is compatible to today’s WDM network in spectrum operation, while still maintaining the flexibility of adaptation between the bit rate and the transparent reach of an optical super-channel, but not requiring expensive flexi-grid WSSs. Specifically, the Quasi-CWDM optical network employs large fixed frequency grids, whose spacing falls between the traditional CWDM and DWDM, e.g., 200 GHz or 400 GHz. To maintain the flexibility between the bit rate and the transparent reach of an optical super-channel, different modulation formats are chosen according to channel physical distances. To minimize network hardware cost and maximize carried user traffic demand, we develop a mixed integer linear programming (MILP) model and a heuristic algorithm that can efficiently groom upper-layer IP traffic onto the optical layer by optical super-channels. We compare the design based on the Quasi-CWDM network to those based on the DWDM network and the advanced EON. It is found that the proposed Quasi-CWDM network has a much lower hardware cost than the other two types of networks, while achieving spectrum efficiency close to EON.

With the rapid growth of traffic and power consumption in information and communication technology industry for decades, improving energy efficiency has become a challenging issue in recent years. Especially, the pervasive access to Internet via mobile devices will cause wireless traffic volume increment by 1000+ times in near future, which is expected to be carried by the fifth generation ultradense cellular network. Following this trend, the core network where optical fibers are deployed to deliver aggregated traffic needs upgrading to accommodate the increasing traffic volume. To match with the traffic growth rate, we should conduct efficient network planning over multiple time periods. Moreover, considering the heterogeneity in the bandwidth requirements among various network services, flexible mixed line rate scheme is adopted in network provisioning. In this paper, we study the long‐term multiperiod planning of optical core network by considering the traffic growth with the objective of high energy‐efficiency. Three planning strategies, say All‐period, Incremental, and End‐of‐Life, respectively, are studied and formulated as mixed integer linear programming models with the objective to minimize power consumption of optical core network. Given the estimation on the reduction of power consumed by various network devices, we can deploy network devices flexibly in each period through the optimization models. Performance of the proposed models is also evaluated and compared via case studies.

From an algorithmic perspective, planning and operating optical networks falls in the broad category of network optimization problems. We give a short introduction on algorithmic techniques that can be used to solve network optimization problems, emphasizing on linear optimization and heuristics. We present examples of applying these techniques to optimize resource allocation during the planning of optical networks. In particular, we focus on fixed-grid WDM networks, which is the current practice, and on flexible optical networks, considered as the most promising architecture for meeting next generation core and metro network requirements. In doing so, we describe a generic problem definition that can capture both types of networks in a unified manner.

Network Interconnection Studies of Distributed Generation

The predicted penetration rates of low carbon technologies (LCTs) for heating and transport will place additional stresses on planning and design activity within Distribution Network Operators (DNOs). DNOs are obliged to provide cost-effective solutions for network reinforcement and designers are faced with the complexities of new technology and a rapidly changing use of the electricity network, particularly at low voltage. Performing network assessments and identifying the most feasible solution places a significant resource burden on network operators. This paper provides an overview of a Network Planning and Design Decision Support (NPADDS) tool which is being developed as part of the UK’s Customer-Led Network Revolution (CLNR) smart grid project. The tool is demonstrated by performing an assessment of a network area based on a range of LCT penetration scenarios for which it proposes solutions based on a database of historical or anticipated costs and benefits.

5G communications will require the effective transmission of new radio signals through fiber networks, in order to facilitate the proliferation of antenna sites as well as greater pooling of resources. Next generation optical access networks can provide an efficient platform for mobile x-haul. Techniques discussed in this paper shows how both wired and 5G wireless services may be converged over a single fiber infrastructure, and how optical networking can be harnessed in order to provide flexible millimeter-wave radio-over-fiber.

Currently optical fiber is largely used in the trunking network; its utilization has been increasing and it is expected to be introduced in access networks. In Brazil, some operating companies are considering the introduction of fiber in the local loop, to provide better services for their key customers. This article considers optical access network planning, describes possible topologies, proposes a network modelling approach and introduces a planning tool called PREST, which is aimed at helping the operating companies to accomplish the definition of a business oriented optical access network (BOAN).

Passive optical network (PON) is an ultimate solution for recent communication technology which accentuates on faster, less expensive and dependable communication system used as access network for optical fiber communication. The broadband carrier suppliers throughout the world are involved to innovate technique to pull down the complexity of network systems, required time of installation, and necessary skill set for installation which finally downsize the overall deployment expenses of the entire network structure. PON imparts one optical fiber to many end users by utilizing power splitters associated with various optical network unit (ONU) situated to customer's premises. One of the fundamental criteria of PON network planning is to design the path of optical link of a point-to-multipoint network which interfaces each end user through the central offices (COs) and power splitter(s), within a lower cost of deployment. This criterion needs to be executed considering the practical restrictions, such as conceivable fiber path, the splitting ratio of optical splitters, position of splitters, and presence of any obstacle on the deployment path. So, here, an algorithm is proposed to decrease the deployment cost by maintaining strategy of lower distance limit with avoiding the obstacle in the fiber path. So, ultimately, by this proposition, the network set-up cost will decrease, and the approximate deployment cost will be possible to compute.KeywordsPONOptimizationONUCORemote node (RN)Power splitterPassive splitter combiner (PSC)Cost estimationEnd user

Web 2.0 applications have become ubiquitous over the past few years because they provide useful features such as a rich, responsive graphical user interface that supports interactive and dynamic content. Social networking websites, blogs, auctions, online banking, online shopping and video sharing websites are noteworthy examples of Web 2.0 applications. The market for public cloud service providers is growing rapidly, and cloud providers offer an ever-growing list of services. As a result, developers and researchers find it challenging when deciding which public cloud service to use for deploying, experimenting or testing Web 2.0 applications. This study compares the scalability and performance of a social-events calendar application on two Infrastructure as a Service (IaaS) cloud services – Amazon EC2 and HP Cloud. This study captures and compares metrics on three different instance configurations for each cloud service such as the number of concurrent users (load), as well as response time and throughput (performance). Additionally, the total price of the three different instance configurations for each cloud service is calculated and compared. This comparison of the scalability, performance and price metrics provides developers and researchers with an insight into the scalability and performance characteristics of the three instance configurations for each cloud service, which simplifies the process of determining which cloud service and instance configuration to use for deploying their Web 2.0 applications. This study uses CloudStone – an open-source, three-tier web application benchmarking tool that simulates Web 2.0 application activities – as a realistic workload generator and to capture the intended metrics. The comparison of the collected metrics indicates that all of the tested Amazon EC2 instance configurations provide better scalability and lower latency at a lower cost than the respective HP Cloud instance configurations; however, the tested HP Cloud instance configurations provide a greater storage capacity than the Amazon EC2 instance configurations, which is an important consideration for data-intensive Web 2.0 applications.

Study and Analysis of Routing and Spectrum Allocation (RSA) and Routing, Modulation and Spectrum Allocation (RMSA) Algorithms in Elastic Optical Networks (EONs)

PON versus AON: Which is the best solution to offload core network by peer-to-peer traffic localization

A Mixed Line Rate (MLR) optical network is a good candidate for a core backbone network because of its ability to provide diverse line rates to effectively accommodate traffic demands with heterogeneous bandwidth requirements. Because of the deleterious effects of physical impairments, there is a maximum transmission reach for optical signals before they have to be regenerated. Being expensive devices, regenerators are expected to be sparsely located and used in such a network, called a translucent optical network. In this paper, we consider the Grooming, Routing, and Wavelength Assignment (GRWA) problem so that the Quality of Transmission (QoT) for connections is satisfied, and the network-level performance metric of blocking probability is minimized. Cross-layer heuristics to effectively allocate the sparse regenerators in MLR networks are developed, and extensive simulation results are presented to demonstrate their effectiveness.

Routing, modulation, and spectrum allocation (RMSA) is fundamental in elastic optical network (EON) planning. In various RMSA algorithms, it is necessary to consider the physical-layer impairments of channel. For example, nonlinear impairments (NLI) results in inaccurate estimation of the channel state, which seriously affects the feasibility of allocation scheme. Considering NLI, this paper proposes a model based on deep neural network (DNN) to conduct channel estimation. Instead of calculating the exact channel matrix parameters for each link to evaluate its availability, the model provides a direct overall estimation of NLI for the entire topology. Furthermore, we designed a corresponding RMSA algorithm, i.e. DBRMSA, to ensure its application. Experiments show that our proposed algorithm can greatly improves spectrum utilization and reduce computational complexity while ensuring transmission accuracy.

Mixed-line-rate (MLR) networks have been proposed recently to support emerging traffic demands with diverse capacity requirements. In such networks, wavelength channels of the optical paths can have a variety of capacities (10/40/100  Gbps). It has been shown that this feature enables new paradigms for protection in optical wavelength-division-multiplexing (WDM) networks. In this paper, we propose to design transparent MLR networks with shared subconnection protection (SSP). SSP in an MLR network, compared with other more classical approaches (dedicated or shared protection), can also address the cost-versus-capacity trade-off in providing shared protection in a transparent network. The design problem is solved by a two-step approach that formulates part of the problem as an integer linear program (ILP). Our results show that SSP enables higher sharing of backup capacity in an MLR network in that the design cost is up to 37% less than a single-line-rate network with SSP and around 40% less than MLR with dedicated protection.