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.

An Energy-Efficient n-Epidemic Routing Protocol for Delay Tolerant Networks

Abstract: In Delay Tolerant Networks (DTN), as disconnections between nodes are frequent, establishing routing path from the source node to the destination node may not be possible. However, if a node transmits packets to all its encounters, its batteries will be used up quickly. Many researches have been done on routing and forwarding algorithms in DTN, but few of them have explicitly address the energy issue. In this paper, we propose n-epidemic routing protocol, an energy-efficient routing protocol for DTN. The n-epidemic routing protocol is based on the reasoning that in order to reach a large audiences with low number of transmissions, it is better to transmit only when the number of neighbors reaching a certain threshold. We compare the delivery performance of n-epidemic routing protocol with basic epidemic routing protocol using both analytical approach and empirical approach with real experimental dataset. The experiment shows that n-epidemic routing protocol can increase the delivery performance of basic epidemic-routing by 434% averagely.

A Database of Age and Gender Annotated Telephone Speech

Abstract: This article describes an age-annotated database of German telephone speech. All in all 47 hours of prompted and free text was recorded, uttered by 954 paid participants in a style typical for automated voice services. The participants were selected based on an equal distribution of males and females within four age cluster groups; children, youth, adults and seniors. Within the children, gender is not distinguished, because it doesn’t have a strong enough effect on the voice. The textual content was designed to be typical for automated voice services and consists mainly of short commands, single words and numbers. An additional database consists of 659 speakers (368 female and 291 male) that called an automated voice portal server and answered freely on one of the two questions “What is your favourite dish?” and “What would you take to an island?” (island set, 422 speakers). This data might be used for out-of domain testing. The data will be used to tune an age-detecting automated voice service and might be released to research institutes under controlled conditions as part of an open age and gender detection challenge.

Techno-economic Analysis of Software Defined Networking as Architecture for the Virtualization of a Mobile Network

Abstract: Worldwide mobile network operators have to spend billions to upgrade their own network to the latest standards for wireless communication of high-speed data for mobile phones (e.g. Long Term Evolution, LTE). This is in contrast with the decline in average revenue per user and threatens: (1) their profitability and (2) the fast adaptation of new standards. Investigating new mechanisms that can decrease the capital expenditures (capex) and operational expenditures (opex) of a mobile network is therefore essential. Enabling multiple mobile network operators on a common infrastructure is one such mechanism. Software defined networks can overcome this problem and a solution based on exploring OpenFlow (OF) as architecture for mobile network virtualization has been proposed. We investigate two network scenarios based on this OF solution in a techno-economic analysis: (scenario 1) software-defined, non-shared networks and (scenario 2) virtualized, shared networks and compare it against the current situation. By doing so, this paper provides insights on the relative cost savings that a mobile network operator can reach through Software Defined Networking (SDN) and network sharing. The techno-economic analysis indicates that SDN and virtualization of the first aggregation stage and second aggregation stage network infrastructure leads to substantial capex cost reductions for the mobile network operator. As a consequence, mobile network infrastructure virtualization through the use of OpenFlow could be one of the problem solvers to tackle the issue of rising costs and decreasing profitability. Still, we did not take into account the direct effect on operational expenditures and the indirect effect that network sharing can adversely affect the ability of the operators to differentiate themselves.

TROLL: a language for object-oriented specification of information systems

Abstract: TROLL is a language particularly suited for the early stages of information system development, when the universe of discourse must be described. In TROLL the descriptions of the static and dynamic aspects of entities are integrated into object descriptions. Sublanguages for data terms, for first-order and temporal assertions, and for processes, are used to describe respectively the static properties, the behavior, and the evolution over time of objects. TROLL organizes system design through object-orientation and the support of abstractions such as classification, specialization, roles, and aggregation. Language features for state interactions and dependencies among components support the composition of the system from smaller modules, as does the facility of defining interfaces on top of object descriptions.