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 & Signal. The organization has 3473 authors who have published 5208 publications receiving 65429 citations. The organization is also known as: DTAG & German Telecom.

An efficient ontology-based expert peering system

Abstract: This paper proposes a novel expert peering system for information exchange. Our objective is to develop a real-time search engine for an online community where users can query experts, who are simply other participating users knowledgeable in that area, for help on various topics. We consider a graph-based scheme consisting of an ontology tree where each node represents a (sub)topic. Consequently, the fields of expertise or profiles of the participating experts correspond to subtrees of this ontology. Since user queries can also be mapped to similar tree structures, assigning queries to relevant experts becomes a problem of graph matching. A serialization of the ontology tree allows us to use simple dot products on the ontology vector space effectively to address this problem. As a demonstrative example, we conduct extensive experiments with different parameterizations. We observe that our approach is efficient and yields promising results. © Springer-Verlag Berlin Heidelberg 2007.

Verfahren zur paketweisen datenübertragung in einem mobilfunknetz

Abstract: Bei einem Verfahren zur paketweisen Datenubertragung in einem Mobilfunknetz mit Mobilstationen und Basisstationen, wobei auf jeweils einer Frequenz eine Vielzahl von Zeitschlitzen zur Verfugung steht, welche Steuer- und Verkehrskanale bilden, wird bei dem Aufbau einer Funkverbindung zur paketweisen Datenubertragung der jeweils beteiligten Mobilstation eine fur die jeweilige paketweise Datenubertragung gultige Kennzahl zugeteilt. Die Ubertragung der einzelnen Datenpakete erfolgt in Verkehrskanalen, die in zugeordneten Steuerkanalen unter Verwendung der Kennzahl als das Datenpaket enthaltene Verkehrskanale gekennzeichnet sind. Es werden ferner Verfahren ohne die Zuteilung einer Kennzahl beschrieben.

Security games for vehicular networks

Abstract: Vehicular ad-hoc networks (VANETs) enabling vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications is an emerging research field aiming to improve transportation security, reliability, and management To better understand networking and security aspects of VANETs, we have been investigating network connectivity issues and mappings of car networks to the underlying road topology Using this mapping and various metrics, we locate hot-spots in vehicular networks to determine the most vulnerable points for jamming We also use these to optimize the placement of roadside units To this end, we first develop quantitative measures for assessment of the importance of road segments in the context of security and traffic flow We then use game theoretic analysis to investigate the effects of possible malicious users on the system for increased reliability and better management of resources For example, we study the optimal deployment of traffic control and security infrastructure both in the static (roadside units) and dynamic case (law enforcement units) We use realistic simulation data, obtained from traffic scientists, as input to our models as well as to evaluate the effectiveness of countermeasures

Verfahren zur Auswahl und Filterung von Verkehrsinformationen

Abstract: Die Erfindung betrifft ein Verfahren zur Auswahl und Filterung von Verkehrsinformationen in einem mobilfunkgestutzten Verkehrsinformationsdienst. Dabei werden die Verkehrsinformationen in einer Verkehrsredaktion einer Dienstzentrale gesammelt und aufbereitet, und der Benutzer kann, je nach dem von ihm gewunschten Informationsumfang, uber ein geeignetes Mobilfunkendgerat wahlweise verschiedene Abfragemodi auswahlen und dadurch verschiedene Verkehrsinformationen von der Dienstzentrale abrufen, wobei der Informationsgehalt der abgerufenen Verkehrsinformationen von der Dienstzentrale unter Berucksichtigung des augenblicklichen Standortes des Benutzers und/oder Angabe eines Fahrtzieles und durch gezielte Filterung benutzerspezifisch aufbereitet wird.

Realizing services and slices across multiple operator domains

Abstract: Supporting end-to-end network slices and services across operators has become an important use case of study for 5G networks as can be seen by 5G use cases published in 3GPP, ETSI as well as NGMN. This paper presents the in- depth architecture, implementation and experiment on a multi­domain orchestration framework that is ab le to deploy such multi-operator service as well as monitor the service for SLA compliance. Our implemented architecture allows operators to abstract their sensitive details while exposing the relevant amount of information to support inter-operator slice creation. Our experiment shows that the implemented framework is capable of creating services across operators while fulfilling the respective service requirements.