Search results for "VDP::Technology: 500::Information and communication technology: 550::Telecommunication: 552"
showing 10 items of 87 documents
Seamless Hand-over Algorithm for Wireless Enterprise Networks
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad The mass deployment of the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11 based wireless local area networks (WLAN) and increased sales in hand-held devices supporting WLAN have resulted in an urgent need to support fast WLAN handovers or roaming. The reason for this problem arising now is that hand-held devices are more mobile than a laptop and their users actively use their hand-held equipment while moving. Laptop users are often called nomadic users in contrast to the real mobile users. The customarily solution is that when a connection is lost with the associated access point, o…
OpenIMS and Interoperability with Asterisk/Sip Express VOIP Enterprise Solutions
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad Nowadays, with the development of the next-generation network, IMS becomes very important, and it will play a key role in the future All-IP infrastructure. But it is still in the developing stage, and it will take time for all 3G mobile networks upgrade to 3GPP networks. Therefore, the research project will study the interoperability solutions between Open Source IMS and Open Source VoIP/SIP implementations. This project is supported by auSystems and HiA. OpenIMS (Open Source IMS) was developed by FOKUS (a Germany institution) in December 2006. It is a free IMS enterprise solution. As it is so new, t…
Handling of IP-Addresses in the Context of Remote Access
2008
Masteroppgave i informasjons- og kommunikasjonsteknologi 2008 – Universitetet i Agder, Grimstad For various reasons (e.g., security, lack of IPv4-addresses) the services in the home smart space only use private IP addresses. This is unfortunate in the remote service access since these addresses frequently appear in responses sent from a service in the remote smart space (e.g., your home) to the visited smart space (e.g., your friend’s home).The Internet Engineering Task Force (IETF) provides some solutions and workarounds for the problem caused by NAT. In this project, the challenge to me is to summarize the available options, rank the options according to which one is preferred for the RA-…
Position technologies for internet connected mobile terminals, offering location based audio services
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad The company Infotain wishes to offer location based audio guiding at museums. They wish that this audio is going to be available through the visitor’s mobile phone. However, to be able to offer location based audio guiding a suitable positioning technology for mobile phones has to be found. Therefore the purpose of this thesis is to gather information about the technologies that can be used for location based information. After the technologies have been thoroughly examined we have to give Infotain a recommendation about what technology seems to best satisfy the demands. Important factors in evaluati…
Performance Analysis of Super-Orthogonal Space-Time Trellis Coded MIMO-OFDM Systems over the One-Ring Channel
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad With the rapid development of wireless communications, the available bandwidth for wireless applications becomes more and more insufficient. Therefore, how to improve data rate without expending bandwidth becomes a main goal in modern communication system design. Recently, two wireless communication schemes, which can be used to effectively combat with multi-path fading, are widely investigated around the world. One is the multiple-input multiple-output (MIMO) technology and another is the orthogonal frequency division multiplexing (OFDM). As a result, a combined system, MIMO-OFDM, can be used for wi…
Mobilteknologi til videokommunikasjon ved trygghetsalarmer
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad Denne rapporten behandler bruk av mobiltelefoner som alarmsentral for hjemmeboende brukere. Studien legger vekt på de forskjellige mobile netts egenskaper og begrensninger som alarmbefordrer. Ønske om videotelefoni som alarm behandles og det foreslås løsninger for å ivareta dette uten å gå på akkord med sikkerhet. Juridiske sider med alarmer og videobilder behandles ut fra to ulike scenario avhengig av om hjelpere er offentlige eller private. Studien er gitt som en del av interregIII prosjektet Grensebroen Arena sin satsning innen emnet “Et år til hjemme” rettet mot eldre hjemme- boende. Prosjektet h…
Implementering av internettbasert pasientjournal i en helseinstitusjon
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad Det utvikles stadig flere internettjenester som gir nye og bedre muligheter for kommunikasjon og utveksling av informasjon. Det norske helsevesen har merket en stor etterspørsel fra pasienter og helsepersonell etter internettbaserte helseløsninger som vil forenkle hverdagen. De første internettbaserte helsetjenestene eksisterer, men disse er helt i startfasen og det er nærmest uendelige muligheter for hva slags tjenester en skal kunne tilby i fremtiden. Sårbarhetene relatert til internett og det strenge lovverket i Norge gjør slike tjenester vanskelig å gjennomføre. Løsningene som skal tilby slike tj…
Struggles for recognition: a content analysis of messages posted on the Internet
2012
Anders Johan W Andersen,1,2 Tommy Svensson31Department of Psychosocial Health, University of Agder, Norway; 2Nordic School of Public Health, Gothenburg, Sweden; 3Department of Behavioral Sciences and Learning, Linköping University, Linköping, SwedenBackground: The Internet has enlarged the possibilities of human communication and opened new ways of exploring perceptions of mental health. This study is part of a research project aiming to explore, describe, and analyze different discourses of mental health in Norway and Sweden, using material from Internet-based services.Aim: To examine messages posed by users of publicly available question-and-answer services and to descri…
Power allocation in multi-channel cognitive radio networks with channel assembling
2011
Accepted version of a paper in the book: 2011 IEEE 12th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC). Published version available from the IEEE:http://dx.doi.org/10.1109/SPAWC.2011.5990485 Consider power allocation for Secondary User (SU) packet transmissions over multiple channels with variable Primary User (PU) arrival rates in cognitive radio networks. Two problems are studied in this paper: The first one is to minimize the collision probability with PUs and the second one is to maximize the data rate while keeping the collision probability bounded. It is shown that the optimal solution for the first problem is to allocate all power onto the bes…
Parameter optimization for amplify-and-forward relaying with imperfect channel estimation
2009
Cooperative diversity is a promising technology for future wireless networks. In this paper, we consider a cooperative communication system operating in an amplify-and-forward (AF) mode with an imperfectly-known relay fading channel. It is assumed that a pilot symbol assisted modulation (PSAM) scheme with linear minimum mean square estimator (LMMSE) is used for the channel estimation. A simple and easy-to-evaluate asymptotical upper bound (AUB) of the symbol-error-rate (SER) is derived for uncoded AF cooperative systems with quadrature amplitude modulation (QAM) constellations. Based on the AUB, we propose a criterion for the choice of parameters in the PSAM scheme, i.e., the pilot spacing …