Auflistung nach Autor:in "Spaniol, Otto"
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- Zeitschriftenartikel400 Jahre Logarithmen(Informatik-Spektrum: Vol. 37, No. 2, 2014) Spaniol, Otto
- KonferenzbeitragA Bayesian Location Estimation Technique for Mobile Ad Hoc Networks(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Caleffi, Marcello; Ferraiuolo, Giancarlo; Paura, LuigiIn this paper1, we propose a simple method to introduce a-priori information in position estimation for mobile ad hoc and sensor networks, in order to improve the estimation accuracy. The a-priori information is derived from the movement of the mobile node with respect to the position of fixed anchor nodes, and it is exploited to perform Bayesian estimation procedure. Numerical simulation results corroborate the effectiveness of the proposed technique, which outperforms the maximum likelihood one.
- KonferenzbeitragCommunity-Aware Mobile Networking(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Kuhn, Michael; Wattenhofer, RogerCommunity related applications such as dating platforms, instant messengers, or file-sharing tools enjoy a great popularity in the Internet. Motivated by this success, community-awareness also has become a hot topic in the mobile world. Despite considerable efforts, however, mobile solutions still cannot compete with their Internet counterparts. A key feature of community-aware applications is profile matching. To a large extent, the missing popularity of mobile approaches can be explained with the problems traditional one-to-one keyword matching causes in a purely decentralized environment: Expressive keywords are unlikely to match because of a lack in user density, and a superficial keyword classification misses the application needs. Hence, we face the challenge to compare characteristic topics in purely mobile applications. To address this challenge, this paper presents a fundamentally new matching scheme based on a combination of topology analysis and distance labeling. Proof-of-concept experiments demonstrate that the proposed scheme has indeed the potential to facilitate the comparison of highly specialized keywords in mobile environments.
- KonferenzbeitragEffective Routing Scheme through Network Load-aware Route Metric in Multi-rate Wireless Mesh Networks(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Youn, Joo-Sang; Kang, Chul-HeeIn multi-rate wireless mesh networks, a mesh node can dynamically modify the data rate on a particular link, in response to the perceived SNR ratio between neighbor nodes. In such networks, existing route selection schemes use a link quality metric based on the expected amount of medium time it takes to successfully transmit a packet. However, these schemes do not take into account the status of network load. Therefore, they may easily result in the network being overloaded. In addition, the application has no way of improving its performance under given network traffic conditions. In this paper, a new route metric that considers both per-hop service delay, estimated using the number of packets waiting for transmission in the output queue at relay nodes, and link quality is proposed. In addition, we propose the network load-aware AODV (NLA-AODV) protocol using the proposed metric. This protocol is implemented in a straightforward manner. The performance evaluation is performed by simulation using OPNET. It is demonstrated that the performance of the routing protocol using the proposed route metric outperforms routing protocols using other existing route metrics in multi-rate wireless mesh networks.
- KonferenzbeitragGraduiertenkollegs: Eliteförderung oder bald Regelfall?(Informatk 2005. Informatik Live! Band 1, 2005) Günther, Oliver; Spaniol, Otto
- ZeitschriftenartikelKonzepte und Bewertungsmethoden für lokale Rechnernetze(Informatik Spektrum: Vol. 5, No. 3, 1982) Spaniol, Otto
- KonferenzbeitragOn the Way to a More Realistic Simulation Environment for Mobile Ad-hoc Networks(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Güneş, Mesut; Wenig, MartinTwo main steps on the way to more realistic simulations of mobile ad-hoc networks are the introduction of realistic mobility and sophisticated radio wave propagation models. Both have strong impact on the performance of mobile ad-hoc networks, e.g. the performance of routing protocols changes with these models. In this paper we introduce a framework which combines realistic mobility and radio wave propagation models. Our approach consists of a mobility generator and an obstacle model for the radio wave propagation. It enables researchers to create realistic simulation setups and thus helps to correctly evaluate new algorithms and protocols. For the mobility generation a wide variety of well understood random mobility models is combined with a graph based zone model, where each zone has its own mobility model. To achieve a realistic radio wave propagation model a ray-tracing approach is used. The integration of these two techniques allows to create simulation setups that closely model reality.
- KonferenzbeitragA personalization and mobility aware service enabler for a service continuity in heterogeneous networks(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Yin, Chunyang; Simoni, Noëmie; Chéné, Ghislain duThe rapid growth of wired and wireless access technologies integrated with great needs of user nomad supporting services provides strong motivations to focus on the service continuity in a heterogeneous environment. In this paper, we present a personalization and mobility aware service enabler through the session mobility to support service continuity. A four-leveled architecture in the aim of obtaining service session mobility is designed first. User personalization enables us to propose an information structure of user preferences (user profile) and heterogeneous resources around him (usage profiles). Then a user level oriented Virtual Private User Network (VPUN) can be automatically constructed which permits to select the most adequate offers according to the user. By constructing a Virtual Private Network in the Service level (VPSN) thanks to VPUN, we can finally obtain service session mobility to response service continuity. A demonstration will be given out in the end to evaluate the service enabler.
- KonferenzbeitragPublishing and Discovery of Mobile Web Services in Peer to Peer Networks(Mobile services and personalized environments – Proceedings of the first international workshop on mobile services and personalized environments, 2006) Srirama, Satish NarayanaIt is now feasible to host Web Services on a mobile device due to the advances in cellular devices and mobile communication technologies. However, the reliability, usability and responsiveness of the Mobile Hosts depend on various factors including the characteristics of available network, computational resources, and better means of searching the services provided by them. P2P enhances the adoption of Mobile Host in commercial environments. Mobile Hosts in P2P can collaboratively share the resources of individual peers. P2P also enhances the service discovery of huge number of Web Services possible with Mobile Hosts. Advanced features like post filtering with weight of keywords and context-awareness can also be exploited to select the best possible mobile Web Service. This paper proposes the concept of Mobile Hosts in P2P networks and identifies the means of publishing and discovery of Web Services in mobile P2P networks.