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.

Vendor-interoperable elastic optical interfaces: Standards, experiments, and challenges [Invited]

Abstract: This paper aims to review the status of standardization activities on the black link (BL) and corresponding alien wavelength concepts. It discusses experimental work on filterless optical networks conducted within a dedicated Deutsche Telekom project. The general prospects and existing challenges concerning elastic extensions of the BL are also assessed. Furthermore, we present relevant work on control and management plane interoperability comprising generalized multi-protocol label switching and transport software defined networking aspects. In the second part of the article, we report on the latest dual-vendor experiments on data plane interoperability in terms of digital signal processing technology for next generation 1.28 Tb/s PM-16QAM super-channels. Finally, we present a network reachability analysis based on the widely used Gaussian noise model in the context of data plane interoperability. This analysis estimates the network-wide impact of the single-vendor versus the dual-vendor approach.

IP-Based Mobile and Fixed Network Audiovisual Media Services

Abstract: This article provides a tutorial overview of current approaches for monitoring the quality perceived by users of IP-based audiovisual media services. The article addresses both mobile and fixed network services such as mobile TV or Internet Protocol TV (IPTV). It reviews the different quality models that exploit packet- header-, bit stream-, or signal-information for providing audio, video, and audiovisual quality estimates, respectively. It describes how these models can be applied for real-life monitoring, and how they can be adapted to reflect the information available at the given measurement point. An outlook gives insight into emerging trends for near- and mid-term future requirements and solutions.

Offloading mobile data from cellular networks through peer-to-peer WiFi communication: A subscribe-and-send architecture

Abstract: Currently cellular networks do not have sufficient capacity to accommodate the exponential growth of mobile data requirements. Data can be delivered between mobile terminals through peer-to-peer WiFi communications (e.g. WiFi direct), but contacts between mobile terminals are frequently disrupted because of the user mobility. In this paper, we propose a Sub-scribe-and-Send architecture and an opportunistic forwarding protocol for it called HPRO. Under Subscribe-and-Send, a user subscribes contents on the Content Service Provider (CSP) but does not download the subscribed contents. Some users who have these contents deliver them to the subscribers through WiFi opportunistic peer-to-peer communications. Numerical simulations provide a robust evaluation of the forwarding performance and the traffic offloading performance of Subscribe-and-Send and HPRO.

Coded 64-CAP ADSL in an impulse-noise environment-modeling of impulse noise and first simulation results

Abstract: This paper presents the performance of various coding schemes for the asymmetrical digital subscriber line (ADSL) in an impulse-noise environment. Impulse noise is considered to be one of the most damaging impairments in the ADSL, in which compressed video signals are delivered to residential customers. The impulse noise used in this study was measured and collected in German telephone networks. Based on this measurement and the corresponding statistical modeling, a simulation model for impulse noise is proposed and its properties are outlined. The coding schemes considered here utilize burst-error correcting Reed-Solomon codes and/or random error correcting trellis codes as well as symbol interleaving between the two codes. It has been found through computer simulations that a proper concatenation of the two codes could increase the immunity against impulse noise compared to an uncoded scheme. Specifically, a concatenated code, using a 2-dimensional 8-state trellis code and a 4-error-correcting Reed-Solomon code with an interleaving depth of 18 symbols, was able to eliminate all the errors caused by the impulse noise used in the study. It has also been found that the trellis codes are not very effective against impulse noise, unless they are used in conjunction with Reed-Solomon codes and a proper symbol interleaving. Performance results of other coding configurations using Reed-Solomon codes with different error-correcting capabilities are also presented. In addition, we also show the performance results when simple array codes are used instead of the Reed-Solomon codes

Combining image and text features: a hybrid approach to mobile book spine recognition

Abstract: Despite the successful use of local image features for large-scale object recognition, they are not effective in recognizing book spines on bookshelves. This is because some book spines contain only text components that do not yield distinguishing image features. To overcome this issue, we develop a new approach that combines a text-based spine recognition pipeline with an image feature-based spine recognition pipeline. The text within the book spine image is recognized and used as keywords to search a book spine text database. The image features of the book spine image are searched through a book spine image database. The search results of the two approaches are then carefully combined to form the final result. We implement the proposed hybrid book recognition pipeline used in a book inventory management system, and conduct extensive experiments to evaluate its performance. The experimental results show that while text-based or image feature-based systems only achieve a recall of 72%, the proposed hybrid system achieves a recall of ~91%.