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.

System and method for real-time map-based lost and found

Abstract: A system and method for lost and found includes enabling information about found objects to be stored in real time. The method further includes enabling adjustment of a field of view of an interactive map. The method further includes receiving a search input for search of a lost object. The method further includes performing a search for the lost object based on at least the stored information about the found objects, the search input, and the field of view of the interactive map. The method further includes enabling results of the search to be overlaid on the interactive map.

System and methodology for using mobile phones in live remote monitoring of physical activities

Abstract: In this paper, we propose a system and methodology for using mobile phones for monitoring physical activities of a user, and its applications in assisting elderly or people with need for special care and monitoring. The method is based on processing acceleration data provided by accelerometers integrated in new mobile phones. As the mobile phone is carried regularly by the user, the acceleration pattern can deliver information related to pattern of physical activities the user is engaged in. This information can be sent to a monitoring server, analyzed and presented as different health related factors for assistance, monitoring and healthcare purposes.

Robust Rate Control for Heterogeneous Network Access in Multihomed Environments

Abstract: We investigate a novel robust flow control framework for heterogeneous network access by devices with multihoming capabilities. Toward this end, we develop an H -optimal control formulation for allocating rates to devices on multiple access networks with heterogeneous time-varying characteristics. H analysis and design allow for the coupling between different devices to be relaxed by treating the dynamics for each device as Independent of the others. Thus, the distributed end-to-end rate control scheme proposed In this work relies on minimum Information and achieves fair and robust rate allocation for the devices. An efficient utilization of the access networks Is established through an equilibrium analysis in the static case. We perform measurement tests to collect traces of the available bandwidth on various WLANs and Ethernet. Through simulations, our approach is compared with AIMD and LQG schemes. In addition, the efficiency, fairness, and robustness of the H -optimal rate controller developed are demonstrated via simulations using the measured real-world network characteristics. Its favorable characteristics and general nature Indicate applicability of this framework to a variety of networked systems for flow control. © 2009 IEEE. ∞ ∞ ∞

A system performance approach to OSNR optimization in optical networks

Abstract: This paper studies a constrained optical signal-to-noise ratio (OSNR) optimization problem in optical networks from the perspective of system performance. A system optimization problem is formulated with the objective of achieving an OSNR target for each channel while satisfying the total power constraint. In order to establish existence of a unique optimal solution, the conditions are derived, which can be used as a basis for an admission control scheme. The original problem is then converted to a relaxed system problem by using a barrier function and solved by a distributed iterative algorithm. Next, the system optimization framework developed is compared to the game theoretic one in [1]. The effects of parameters in both formulations are investigated to study efficiency of Nash equilibria in the OSNR game and pricing mechanisms affecting overall system performance. The theoretical analysis is supported by numerical simulations and experiments conducted on an optical fiber link.