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.

Measurements of PMD in the installed fiber plant of Deutsche Telekom

Abstract: In this paper, PMD measurements that were carried out in the installed fiber plant of Deutsche Telekom, which consists solely of G.652 fiber, are presented. The measurements are performed all over Germany during the last three years on nearly 10,000 fiber sections whereby these fiber cables were installed from 1985 to 2001. It should be noted that pre-1994 cables PMD was not yet specified by cable manufacturers and PMD specification were only added around 1995. Fibers with lowest PMD were identified and reserved for high capacity transmission. The data indicate that no direct correlation of the first-order PMD coefficient value with the rollout of the PMD specification by the fiber and cable manufacturers is feasible. Even for cables which were installed during 1985 till 1991 a reasonable number of fibers is suitable for 40 Gbit/s transmission. For 10 Gbit/s selected fibers are used, thus PMD does not impose any limitations and therefore avoiding expensive exchange of fibers.

Optimal New Site Deployment Algorithm for Heterogeneous Cellular Networks

Abstract: With exponential growth of mobile broadband traffic, mobile operators are facing the challenge of cost-efficiently evolving 3G/4G network to meet future network capacity demand. Heterogeneous multilayer network deployment is one essential performance-effective and potentially cost-effective candidate solution. We study optimal new site deployment algorithms in heterogeneous wireless cellular networks. We focus on a joint Macro and Micro layer new site deployment. We propose and evaluate a class of fast-convergent meta-heuristic algorithms: Scalable Multi-radio deployment AlgoRiThm (SMART). Their performances and convergence speeds are evaluated using a large-scale real dense-urban HSPA network deployment. We compare the performance on four variants of SMART: Greedy, Simulated Annealing, Greedy with memory and Simulated Annealing with memory. We show that the Simulated Annealing and Greedy algorithms achieve almost the same optimal deployment when the number of optimization iterations is large and, the Greedy algorithm converges much faster than Simulated Annealing algorithm when the number of optimization iterations is small. We also show that in a practical network deployment scenario SMART outperforms previous heuristic deployment algorithms proposed in the literature.

Verfahren zur routenplanung und zielführung von fahrzeugen

Abstract: Die Erfindung betrifft ein Verfahren zur Routenanfrage und Zielfuhrung von Fahrzeugen unter Anwendung eines oder mehrerer Ortungsverfahren, eines in Form einzelner Wegesegmente in einer Zentrale elektronisch gespeicherten Wegenetzes und eines in der Zentrale angesiedelten Routenplanungs- und/oder Optimierungsmoduls. Das Verfahren is dadurch gekennzeichnet, dass ein Mobilkommunikationssystem, bestehend aus Mobilfunk-Netz und Mobilfunk-Endgeraten verwendet wird, in der Zentrale eine Routenplanung auf Benutzeranfrage stattfindet, wobei die Routenplanung nach anfrage- und/oder fahrzeug- und/oder benutzerindividuellen Optimierungskriterien erfolgt, in der Zentrale eine Zielfuhrungswurzel generiert wird, in welcher als wichtige Information eine routenindividuelle Verkettung und Sequenz von Wegesegmenten enthalten ist, in der Zentrale aus der Zielfuhrungswurzel und Zusatzinformationen eine individuelle Routenbeschreibung generiert wird, welche zum Endgerat ubertragen und dort weitgehend autark abgearbeitet wird.

Method and device for accurately dating an electronic document

Abstract: In a method for verifying the instant that a transaction is implemented or that a document is created, signed, sent and/or received, it is provided for a time marker to be inserted into the document in a tamper-proof manner, and for the time marker to correspond to a time stamp taken from a non-adjustable clock. An arrangement for performing the method is also provided.

Method for customized data output on a web site

Abstract: The invention concerns a method for customized data output on a web site, whereby specific data can be added to the content of a web site in targeted manner for an Internet user or a specific group of persons. The invention aims at enabling customization up to the level of the individual Internet user. Therefor, a list of preferences is filed for the user in a databank of his Internet service provider (ISP), for example under his client number. When the user calls a web site, the web server contacted by the user requests said preferences from the ISP. Said server transmits to the databank server, on querying the databank, the temporary IP address from which the web site has been called. The databank server accesses through an inverse RADIUS request the user's preferences and transmits them to the web server which uses said preferences to add to the called web site the customized data corresponding to said preferences.