Fritz-Joachim Westphal

Modeling operational expenditures for telecom operators

This paper introduces an operational expenditures (OpEx) cost model for telecom operators. In order to give a general overview, all operational expenditures are classified according to a matrix structure. The most important processes to operate an existing network are indicated. The processes for routine operation, reparation, service provisioning and pricing and billing are discussed in detail. Starting from the description of those processes, it is possible to derive formulae to calculate the actual OpEx cost for a certain network scenario. The needed methodology is described in the paper. Finally, we indicate how the used network technology and the offered network services influence the overall OpEx cost.

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.

Evolution of Terrestrial Optical System and Core Network Architecture

Optical systems and technologies have been radically changing the telecommunication networks for past 15 years; today wavelength division multiplexing (WDM) technology, optical amplifiers, and simple optical switching elements like optical add-drop multiplexers (OADMs) are used in the backbone networks of all operators worldwide. Optical systems nowadays provide the basis for cost-effective transmission of large amounts of bandwidth over the Internet, and will enable its future growth and the spreading of new applications and services. This paper summarizes the main trends in optical networking and investigates potential future application areas. Optical system technology has become so pervasive in network design that it needs to be considered in the context of provisioning new applications and services. Therefore, the analysis is not limited to the aspects of physical transmission, but also takes into account recent developments in integrated network design as well as network control and management. The following sections describe the key functionalities of future optical network architectures, and the key findings of the theoretical analysis are supported by the results of a field trial of advanced transmission technology

Energy trade-offs among content delivery architectures

It is envogue to consider how to incorporate various home devices such as set-top boxes into content delivery architectures using the Peer-to-Peer (P2P) paradigm. The hope is to enhance the efficienc of content delivery, e.g., in terms of reliability, availability, throughput, or to reduce the cost of the content delivery platform or to improve the end user experience. While it is easy to point out the benefit of such proposals they usually do not consider the implications with regards to the energy costs. In this paper we explore the energy trade-offs of such P2P architectures, data center architectures, and content distribution networks (CDNs) by building upon an energy consumption model of the transport network and datacenters developed in the context of Internet TV (IPTV). Our results show that a CDN within an ISP is able to minimize the overall power consumption. While a P2P architecture may reduce the power consumption of the service provider it increases the overall energy consumption.

Towards Unified Programmability of Cloud and Carrier Infrastructure

The rise of cloud services poses considerable challenges on the control of both cloud and carrier network infrastructures. While traditional telecom network services rely on rather static processes (often involving manual steps), the wide adoption of mobile devices including tablets, smartphones and wearables introduce previously unseen dynamics in the creation, scaling and withdrawal of new services. These phenomena require optimal flexibility in the characterization of services, as well as on the control and orchestration of both carrier and cloud infrastructure. This paper proposes a unified programmability framework addressing: the unification of network and cloud resources, the integrated control and management of cloud and network, the description for programming networked/cloud services, and the provisioning processes of these services. In addition proofs-of-concept are provided based on existing open source control software components.

UNIFYing Cloud and Carrier Network Resources: An Architectural View

Cloud networks provide various services on top of virtualized compute and storage resources. The flexible operation and optimal usage of the underlying infrastructure are realized by resource orchestration methods and virtualization techniques developed during the recent years. In contrast, service deployment and service provisioning in carrier networks have several limitations in terms of flexibility, scalability or optimal resource usage as the built-in mechanisms are strongly coupled to the physical topology and special purpose hardware elements. Network Function Virtualization (NFV) opens the door between cloud and carrier networks by providing software-based telecommunication services which can run in virtualized environment on general purpose hardwares. Our main goal is to unify software and network resources in a common framework. In this paper, we propose a novel architecture supporting automated, dynamic service creation based on a fine-granular service chaining model, SDN and cloud virtualization techniques. First, we introduce the architecture with the main components. Second, the most important benefits are highlighted and compared to other state-of-the-art approaches. Finally, preliminary experiences with our proof-of-concept prototypes are presented.

Service provider DevOps for large scale modern network services

Network service providers are facing challenges for deploying new services mainly due to the growing complexity of software architecture and development process. Moreover, the recent architectural innovation of network systems such as Network Function Virtualization (NFV), Software-defined Networking (SDN), and Cloud computing increases the development and operation complexity yet again. One of the emerging solutions to this problem is a novel software development concept, namely DevOps, that is widely employed by major Internet software companies. Although the goals of DevOps in data centers are well-suited for the demands of agile service creation, additional requirements specific to the virtualized and software-defined network environment are important to be addressed from the perspective of modern network carriers. In this paper, we thoroughly debate DevOps requirements for developing a modern service creation platform by taking EU FP7 project UNIFY as a reference architecture and suggest the corresponding extensions of UNIFY interfaces that meet the discovered requirements.

Softwarization of carrier networks

Abstract Carrier networks are faced with continuous transformations of their technology platforms in order to keep up with the changing customer demands. This paper will show how the transition from stovepipe networks to layered architectures enabled the shift to a future network design based on a network operation system (NetOS) operating the ICT fabric containing merely any kind of resources. Basic, underlying concepts are presented and detailed how they will be integrated in this environment. Software components and related development and management processes are becoming an integrated part of this future carrier environment, representing a softwarization of carrier networks. Key technology enablers are Software Defined Networking and Network Function Virtualisation as well as general availability of compute, storage and networking resources. Existing “Network as a Service” approach benefit from this improvements with virtualization, control plane flexibility and adoption of Operation, Administration and Maintenance (OAM) feature to the latest developments. But carrier services will need additional improvements, resulting in the the presented paradigm of “Generic Resources as a Service”. This novel concept will fulfill most demands for flexible service composition, multi-provider and -domain support, automated deployment and operation.

Guest editorial: Network and service virtualization

The introduction of software-defined networking (SDN) and network function virtualization (NFV) has altered, in a wholesale manner, the way to plan for network infrastructure evolution in the forthcoming decade. This Feature Topic aims to provide a concise reference entry point to a wider audience with respect to carrier-grade networking and service virtualization with emphasis on automating the entire networking and cloud infrastructure. The first steps in network virtualization are already taking place today, although more often than not through a piecemeal approach that simply replaces hardware-based network appliances with software-based alternatives. This may help to reduce operator costs in the mid-term but does not alter the full life cycle of service creation and deployment. The real potential for network and service virtualization lies in upgrading the entire toolbox network operators have at their disposal, as state-of-the-art research and development efforts already indicate. For example, the European FP7 UNIFY project defines an architecture where the entire network, from home devices to data centers, forms a unified production environment, a dynamic service creation platform able to distribute functions and state anywhere in the network, aided by automated orchestration engines; see www.fp7-unify.eu for more details. While drafting the Call for Papers for this Feature Topic, our first goal was to attract high-quality contributions from operator and industry research labs as this topic is particularly pertinent to practitioners in the field. Carriers, in particular, can be the main beneficiaries from the emerging infrastructures based on NFV, SDN, and cloud technologies. Therefore, articles by authors working at global operators currently developing, evaluating, and standardizing solutions for network and service virtualization were particularly welcome and encouraged. In this sense, we are glad that all five selected papers for publication in this issue are penned by experts affiliated with European, American, and Asian carriers.

MobiThin management framework: design and evaluation

In thin client computing, applications are executed on centralized servers. User input (e.g. keystrokes) is sent to a remote server which processes the event and sends the audiovisual output back to the client. This enables execution of complex applications from thin devices. Adopting virtualization technologies on the thin client server brings several advantages, e.g. dedicated environments for each user and interesting facilities such as migration tools. In this paper, a mobile thin client service offered to a large number of mobile users is designed. Pervasive mobile thin client computing requires an intelligent service management to guarantee a high user experience. Due to the dynamic environment, the service management framework has to monitor the environment and intervene when necessary (e.g. adapt thin client protocol settings, move a session from one server to another). A detailed performance analysis of the implemented prototype is presented. It is shown that the prototype can handle up to 700 requests/s to start the mobile thin client service. The prototype can make a decision for up to 700 monitor reports per second.