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.

2-State (semi-)Markov processes beyond Gilbert-Elliott: Traffic and channel models based on 2 nd order statistics

Abstract: Two-state Markov models are applied in many performance evaluation studies as a simple form of autocorrelated processes, starting with Gilbert-Elliott channels for the analysis of transmission protocols subject to error bursts. We derive an explicit formula for the 2nd order statistics of 2state semi-Markov processes in order to adapt them to correlated traffic and error processes. State and transition specific distribution functions are included in a general representation covering the special cases being usually studied in the literature. The results reveal the influence of model parameters on short and long term dependency and give rise to a straightforward procedure for parameter adaption. In general, 2-state models provide a 2-dimensional fitting space, whereas special 2-state cases often have only one parameter left to fit the shape of the 2nd order statistics. In our evaluation of IP packet measurements on aggregation links we experienced that adaptations by general 2state Markov models achieve a much closer fit to the traffic variability in different time scales than self-similar processes.

AlGaInAs/InP 1.5 µm MQW DFB laser diodes exceeding 20 GHz bandwidth

Abstract: Buried mushroom multiquantum well DFB laser diodes with compressively strained GaInAs quantum wells and asymmetric confinement layer design are fabricated with a combined MBE/MOCVD technology. Packaged devices exhibit high –3 dB IM bandwidths for very low bias levels and a record bandwidth for this material system of 21 GHz.

Method for controlling a communication device, communication device, system, and computer program product

Abstract: The invention related to a method for the configuration of a communication device, a communication device, a system for the configuration of a communication device, and a computer program product comprising a computer-readable storage medium, wherein the communication device is in communication with an image capture device, wherein the communication device comprises a data processor, wherein a plurality of images comprising a visual code is captured by the image capture device, wherein the visual code of the plurality of images is decoded by a decoding application that is executed by the data processor, wherein the visual code of the plurality of images control at least partly the configuration of the communication device.

The Design Space of Ubiquitous Mobile Input

Abstract: The mobile phone is the first truly pervasive computer. In addition to its core communications functionality, it is increasingly used for interaction with the physical world. This chapter examines the design space of input techniques using established desktop taxonomies and design spaces to provide an in-depth discussion of existing interaction techniques. A new five-part spatial classification is proposed for ubiquitous mobile phone interaction tasks discussed in our survey. It includes supported subtasks (position, orient, and selection), dimensionality, relative vs. absolute movement, interaction style (direct vs. indirect), and feedback from the environment (continuous vs. discrete). Key design considerations are identified for deploying these interaction techniques in real-world applications. Our analysis aims to inspire and inform the design of future smart phone interaction techniques.