Bram Naudts

Techno-economic Analysis of Software Defined Networking as Architecture for the Virtualization of a Mobile Network

Worldwide mobile network operators have to spend billions to upgrade their own network to the latest standards for wireless communication of high-speed data for mobile phones (e.g. Long Term Evolution, LTE). This is in contrast with the decline in average revenue per user and threatens: (1) their profitability and (2) the fast adaptation of new standards. Investigating new mechanisms that can decrease the capital expenditures (capex) and operational expenditures (opex) of a mobile network is therefore essential. Enabling multiple mobile network operators on a common infrastructure is one such mechanism. Software defined networks can overcome this problem and a solution based on exploring OpenFlow (OF) as architecture for mobile network virtualization has been proposed. We investigate two network scenarios based on this OF solution in a techno-economic analysis: (scenario 1) software-defined, non-shared networks and (scenario 2) virtualized, shared networks and compare it against the current situation. By doing so, this paper provides insights on the relative cost savings that a mobile network operator can reach through Software Defined Networking (SDN) and network sharing. The techno-economic analysis indicates that SDN and virtualization of the first aggregation stage and second aggregation stage network infrastructure leads to substantial capex cost reductions for the mobile network operator. As a consequence, mobile network infrastructure virtualization through the use of OpenFlow could be one of the problem solvers to tackle the issue of rising costs and decreasing profitability. Still, we did not take into account the direct effect on operational expenditures and the indirect effect that network sharing can adversely affect the ability of the operators to differentiate themselves.

Towards NFV-based multimedia delivery

The popularity of multimedia services offered over the Internet have increased tremendously during the last decade. The technologies that are used to deliver these services are evolving at a rapidly increasing pace. However, new technologies often demand updating the dedicated hardware (e.g., transcoders) that is required to deliver the services. Currently, these updates require installing the physical building blocks at different locations across the network. These manual interventions are time-consuming and extend the Time to Market of new and improved services, reducing their monetary benefits. To alleviate the aforementioned issues, Network Function Virtualization (NFV) was introduced by decoupling the network functions from the physical hardware and by leveraging IT virtualization technology to allow running Virtual Network Functions (VNFs) on commodity hardware at datacenters across the network. In this paper, we investigate how existing service chains can be mapped onto NFV-based Service Function Chains (SFCs). Furthermore, the different alternative SFCs are explored and their impact on network and datacenter resources (e.g., bandwidth, storage) are quantified. We propose to use these findings to cost-optimally distribute datacenters across an Internet Service Provider (ISP) network.

Deploying SDN and NFV at the speed of innovation: toward a new bond between standards development organizations, industry fora, and open-source software projects

Standards development organizations (SDOs) exist to assure the development of consensus- based, quality standards. These formal standards are needed in the telecommunications market to achieve functional interoperability. The standardization process takes years, and then a vendor still needs to implement the resulting standard in a product. This prevents service providers (SPs) who are willing to venture into new domains from doing so at a fast pace. With the development of software-defined networking (SDN) and network function virtualization (NFV), opensource technology is emerging as a new option in the telecommunications market. In contrast to SDOs, open-source software (OSS) communities create a product that may implicitly define a de-facto standard based on market consensus. Therefore, SPs are drawn to OSS, but they face technical, procedural, legal, and cultural challenges due to their lack of experience with open software development. The question therefore arises, how the interaction between OSS communities, SDOs, and industry fora (IF) can be organized to tackle these challenges.

How can a mobile service provider reduce costs with software-defined networking?

Summary Network architecture innovation has been driven by virtualization and centralization of network control based on software-defined networking (SDN) and by network functions moved to the cloud with network function virtualization (NFV). These two principles are considered as promising enablers to reduce costs and spur innovation. In the first part of the paper, we argue that the evolved packet system (EPS) can be seen as a service function chain and an area in which service providers can capitalize on SDN and NFV capabilities. A multi-layer modular architecture for carrier networks based on SDN and NFV principles is provided. In the second part of the paper, we focus solely on SDN, and we argue that service providers can benefit from SDN to reach cost savings in their mobile network. Our work focuses on the cost savings that can be reached via the centralization of control and the operational paradigm of developing and operating the network management software in-house instead of buying a vendor solution only. We quantify the potential cost savings that can be reached in an Internet protocol/multi-protocol label switching-based transport service with SDN capabilities that interconnects the key functional elements in a mobile network. In the analysis, we evaluate the impact on capital expenditures and provide details on the impact on operational expenditures. The evaluation can serve as a blueprint for techno-economic analysis of the mobile network operators processes in the transport network of a mobile network. Copyright

Can open-source projects (re-)shape the SDN/NFV-driven telecommunication market?

Abstract Telecom network operators face rapidly changing business needs. Due to their dependence on long product cycles they lack the ability to quickly respond to changing user demands. To spur innovation and stay competitive, network operators are investigating technological solutions with a proven track record in other application domains such as open source software projects. Open source software enables parties to learn, use, or contribute to technology from which they were previously excluded. OSS has reshaped many application areas including the landscape of operating systems and consumer software. The paradigm shift in telecommunication systems towards Software-Defined Networking introduces possibilities to benefit from open source projects. Implementing the control part of networks in software enables speedier adaption and innovation, and less dependencies on legacy protocols or algorithms hard-coded in the control part of network devices. The recently proposed concept of Network Function Virtualization pushes the softwarization of telecommunication functionalities even further down to the data plane. Within the NFV paradigm, functionality which was previously reserved for dedicated hardware implementations can now be implemented in software and deployed on generic Commercial Off-The Shelf (COTS) hardware. This paper provides an overview of existing open source initiatives for SDN/NFV-based network architectures, involving infrastructure to orchestration-related functionality. It situates them in a business process context and identifies the pros and cons for the market in general, as well as for individual actors.

Modeling legal and regulative requirements for ranking alternatives of cloud-based services

The decision to adopt a new technology in an organization is a complex task because of several Non-Functional Requirements (NFR) e.g., availability, interoperability, and presence of several alternatives, e.g., service providers can offer multiple packages. To support such a decision and to select the best alternative a Trade-off based Adoption Methodology for Cloud-based Infrastructure and Services (TrAdeCIS), based on NFR for cloud-based services, was proposed. This methodology makes the decision based on multi-criteria decision algorithms, namely the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and the Analytic Network Process (ANP). However, in addition, the decision for adopting cloud-based services is also influenced by the presence of various legal and regulative constraints. Therefore, it is crucial to understand, identify, and model the effect of such constraints on the evaluation of NFR and available alternatives. This paper, therefore, uses the Goal-oriented Requirement Language (GRL) to model the effect of legal and regulative constraints on ranking available alternatives with respect to NFR. The paper also discusses the extensibility and applicability of this methodology to other domains that require evaluating the effect of legal and regulative constraints on the adoption decision. To illustrate this, decisions within the domain providing better voice and data quality on-board train is also discussed in this paper.

Insights in the cost of continuous broadband Internet on trains for multi-service deployments by multiple actors with resource sharing

The economic viability of broadband Internet services on trains has always been proved difficult, mainly due to a high investment cost and low willingness to pay by train passengers, but also due to unused opportunities such as non-passenger services (e.g. train performance monitoring, crew services) and optimization of the resources consumed to offer Internet services. Evaluating opportunities to improve the return on investment is therefore essential towards profitability of the business case. By efficiently sharing resources amongst services, costs can be pooled over several services in order to reduce the investment cost per service. Current techno-economic evaluation models are hard to apply to cost allocation in a multi-service deployment with multiple actors and resource sharing. We therefore propose a new evaluation model and apply it to a deployment of Internet services on trains. We start with a detailed analysis of the technical architecture required to provide Internet access on trains. For each component, we investigate the impact by the different services on resource consumption. The proposed techno-economic evaluation model is then applied in order to calculate the total cost and allocate the used and unused resources to the appropriate services. In a final step, we calculate the business case for each stakeholder involved in the offering of these services. This paper details the proposed model and reports on our findings for a multi-service deployment by multiple actors. Results show important benefits for the case that considers the application of resource sharing in a multi-service, multi-actor scenario and the proposed model produces insights in the contributors to the cost per service and the unused amount of a resource. In addition, ex-ante insights in the cost flows per involved actor are obtained and the model can easily be extended to include revenue flows to evaluate the profitability per actor. As a consequence, the proposed model should be considered to support and stimulate upcoming multi-actor investment decisions for Internet-based multi-service offerings on-board trains with resource sharing.

Internet on trains: A multi-criteria analysis of on-board deployment options for on-train cellular connectivity

A train journey could be an ideal moment to answer a phone call, read an e-mail or browse the Internet on a personal device such as a smartphone, tablet or laptop. Unfortunately, a train is a very challenging environment to provide a mobile network service to due to attenuation and bad coverage leading to dropped phone calls and unreachable Internet services. Improving mobile network service on-board trains, however, is costly and should be planned carefully. A multi-criteria comparison of different deployment options is therefore essential toward an optimal investment decision. But, the impact of the choice of on-board distribution system is often overlooked. This article compares three types of on-board signal repeaters side-by-side: IP-based data access points, wideband repeaters and small cells. The differences in terms of network coverage, human exposure, deployment cost, revenue model and telecommunications policy are analyzed for each of them.

Planning omni-present networks of the future

On one hand, customers expect mobile broadband at any time and place at increasing bandwidth while on the other hand there is an evolution towards smart cities which include video monitoring and large amount of extra sensors putting additional strain on the existing network. Because of this, optimal long term network planning is of crucial importance. This planning has to take into account the ever increasing bandwidth demand and user adoption. In this publication, a genetic algorithm is proposed to find the optimal location of base stations to achieve a full coverage. Using this algorithm, a clear comparison has been made between a short-term (incremental) and a long-term (anticipated) planning.

Insights in costing of continuous broadband internet on trains to allow delivering value via services

Continuous broadband Internet on trains is at the moment being deployed worldwide but not always profitable. Solely providing internet for travellers will have a negative return on investment. But, different service providers could be interested to share the unused capacity of resources deployed to offer other services. In this way, resources and their costs are shared over several services and revenues may rise above the total cost. Service operators should therefore be able to make well informed decisions based on an ex-ante estimate of the cost of a service. Using activity based costing (ABC), we investigate on the one hand how to determine the total cost of resources supplied and on the other how to estimate the cost of consumed resources of a service. Our results show that ABC can adequately cope with the case specific nature of the rollout of services on a train. ABC provides insights in the contributors to the cost per service and the unused capacity. Moreover, obtained results can be used to distribute the cost based on the usage of resources, activities and services, evaluate the service mix and identify candidates for outsourcing. Still, ABC does not give insight in how the unused capacity of a resource should be allocated. The optimal allocation of unused capacity will therefore remain the focus of future work.