Deutsche Telekom

About: Deutsche Telekom is a company organization based out in Welwyn Garden City, United Kingdom. It is known for research contribution in the topics: Telecommunications network & Terminal (electronics). The organization has 3473 authors who have published 5208 publications receiving 65429 citations. The organization is also known as: DTAG & German Telecom.

Method and system for efficient use of a telecommunications network and the connection between the telecommunications network and a customer premises equipment

Abstract: The present invention relates to a method and a telecommunications network for efficient use of a telecommunications network and a CPE, the method comprising the steps of: -- establishing a physical communication channel between the access node of the telecommunications network and the CPE using a line ID for authentication and authorization, -- the telecommunications network providing a public or private Internet Protocol address to the CPE for use by the CPE to communicate with the access node of the telecommunications network, the Internet Protocol address being associated with at least one parameter of the physical communication channel, -- a location information related to the physical communication channel being stored by the telecommunications network (5) -- the telecommunications network initially assigning a first functionality level to the public or private Internet Protocol address, -- the telecommunications network assigning a second functionality level to the public or private Internet Protocol address, in case that the telecommunications network is able to federate the at least one parameter of the physical communication channel to a contract related identification information, -- the location information being used by the location based application.

Coded 64-CAP ADSL in an impulse-noise environment-simulation results

Abstract: This paper describes performance results of E1-ADSL (2.048 Mb/s asymmetrical digital subscriber line) transmission based on carrierless amplitude/phase modulation (CAP) in an impulse-noise environment. Various coding schemes for error protection are investigated. Code options are Reed Solomon code with interleaving, array code and trellis coding, or interleaved trellis coding. The simulation results are based on real measured impulses from an impulse-noise measurement campaign carried out by German Telekom. The inter-arrival times between impulses were either assumed to be constant (worst-case scenario) or were delivered from a distinctive stochastic generator with an inter-arrival time density according to a model also derived in the German campaign. It was found that the RS codes, even with a quite small error-correcting capability, achieved acceptable error performance. Array codes can also be a low-complexity alternative. Trellis coding alone, as expected, was not very effective against the impulse noise.

Collective stresses drive competition between monolayers of normal and Ras-transformed cells

Abstract: We study the competition for space between two cell lines that differ only in the expression of the Ras oncogene. The two cell populations are initially separated and set to migrate antagonistically towards an in-between stripe of free substrate. After contact, their interface moves towards the population of normal cells. We interpret the velocity and traction force data taken before and after contact thanks to a hydrodynamic description of collectively migrating cohesive cell sheets. The kinematics of cells, before and after contact, allows us to estimate the relative material parameters for both cell lines. As predicted by the model, the transformed cell population with larger collective stresses pushes the wild type cell population.

On the benefit of virtualization: strategies for flexible server allocation

Abstract: Network virtualization [2] is an intriguing paradigm which loosens the ties between services and physical infrastructure. The gained flexibility promises faster innovations, enabling a more diverse Internet and ensuring coexistence of heterogeneous virtual network (VNet) architectures on top of a shared substrate. Moreover, the dynamic and demand driven allocation of resources may yield a “greener Internet” without sacrificing (or, in the presence of the corresponding migration technology: with improved!) quality-of-service (QoS) / quality-ofexperience (QoE). This paper attends to a fundamental challenge in the field of network virtualization: the flexible allocation and migration of servers. As a generic use case, we consider a network operator offering a flexible service to a set of dynamic or mobile users, and we present a model that captures the main cost factors in such a system. This allows us to shed light on the benefit of the flexible allocation and the use of migration. Although our cost model is described from a network virtualization perspective, it is not limited to such architectures: similar tradeoffs exist, e.g., in classic cloud networks, in content distribution networks, in the deployment of multicast reflectors or mirrored web content, or in cache placement. Our algorithms and insights are quite general and applicable to various scenarios, ranging from business applications such as SAP services in the cloud, to entertainment applications such as mobile gaming. Concretely, the algorithms presented in this paper guarantee a low access latency by adapting the resources over time while taking into account the corresponding costs: communication cost, allocation cost, migration cost (e.g., service interruption), and cost of running the servers. The algorithms come in two flavors, exploring the extremal perspectives: online algorithms where allocation decisions are done without any information on future requests, and offline algorithms where the (e.g., periodic) demand is known ahead of time. Both algorithms are applicable to various delay models (access latency, delay due to different load functions, etc.). Moreover, we also describe an optimal offline but static algorithm that allows us to quantify the cost-benefit tradeoffs of dynamic resource allocation, and thus to shed light on fundamental questions such as the use of migration compared to solutions using static servers. For example, our simulations show that the overall cost can be higher (by up to hundred percent), if resources are static, in particular if the demand dynamics is moderate. The content of this workshop paper is based on the longer arXiv report 1011.6594; please refer to the technical report for more details.

Verfahren zur abrechnung von internet-dienstleistungen über mobilfunk

Abstract: Die Erfindung betrifft ein Verfahren zur Abrechnung von Internet-Dienstleistungen uber Mobilfunk. Ein Mobilfunkkunde bezahlt beim Surfen im Internet z. B. mittels eines WAP-fahigen Endgerats (Wireless Application Protocol) fur bestimmte Inhalte (Information, Datenbankrecherche, Fahrplanauskunft, Spiele, etc) jeweils einen geringen Einzelbetrag. Dieser kann erfindungsgemas uber das Mobilfunknetz effizient und sicher abgerechnet werden. Die fur eine Bezahltransaktion erforderlichen Kundendaten werden erfindungsgemas zentral in einer Datenbank eines Payment-Gateway gehalten. Der Kunde kann gegenuber dem Anbieter ein Guthaben authorisieren, von welchem der Anbieter die angefallenen Abrechnungsbetrage abbucht.