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Optimaliserer bruk av ledig nettkapasitet

Indika Anuradha Mendis Balapuwaduge disputerer for ph.d.-graden med avhandlingen «Channel Access and Reliability Analysis in Cognitive Radio Networks». (Foto: Privat)

So far, the analysis of the reliability aspect of CRNs from a dependability perspective still remains as a nearly un-chartered topic. To fill this gap, we introduce a set of reliability and availability metrics.

Indika Anuradha Mendis Balapuwaduge

Ph.d.-kandidat

Indika Anuradha Mendis Balapuwaduge forsker på hvordan ledig nettkapasitet kan utnyttes best mulig og samtidig være mest mulig pålitelig.

Utnyttelse av kapasitet i nettverk ved at sekundærbrukere utnytter ledige frekvenser i primærbrukernes nett, er noe som opptar mange. Balapuwaduge har i sin avhandling funnet fram til en kø-ordning som sikrer at brukerne i det sekundære nettverket får en mest mulig pålitelig oppkobling.

Indika Anuradha Mendis Balapuwaduge disputerer på Fakultet for teknologi og realfags doktorgradsprogram med spesialisering i IKT.

Slik beskriver kandidaten selv essensen i avhandlingen:

Channel Access and Reliability Performance in Cognitive Radio Networks: Modeling and Performance Analysis

During the past one and a half decade, cognitive radio networks (CRNs) have received considerable attention from both academia and spectrum regulatory bodies in order to promote efficient spectrum utilization by allowing unlicensed users (secondary users) exploit the vacant frequency bands of the licensed users (primary users).

The concept of CRN has inspired innumerable research ideas and efforts to explore dynamic spectrum access (DSA) strategies to provide satisfactory performance for both secondary and primary networks.

Two dissertation objectives

The objective of this doctoral dissertation is two folds, as 1) to design and analyze DSA schemes under different network scenarios; and 2) to assess the reliability aspect of DSA from a dependability perspective

To design and analyze DSA schemes, this dissertation focuses on enabling more channel access opportunities for secondary users by employing four techniques: channel aggregation; priority-based queues; spectrum leasing; and channel reservation.

In particular, two priority-based queuing schemes are proposed for DSA strategies supported by channel aggregation.

Next, considering the willingness of primary networks to lease a part of their licensed spectrum to the secondary network, both static and dynamic spectrum leasing schemes are proposed in CRNs.

Moreover, channel reservation is studied as an effective technique to ensure service completion of ongoing transmissions in CRNs.

Reliability

So far, the analysis of the reliability aspect of CRNs from a dependability perspective still remains as a nearly un-chartered topic.

To fill this gap, we introduce a set of reliability and availability metrics including various system times in accordance with the International Telecommunication Union’s recommendations and dependability theory.

 

Disputasfakta:

Kandidaten: Indika Anuradha Mendis Balapuwaduge received his B.Sc. Eng. degree with 1st class honors from the University of Ruhuna, Sri Lanka, in 2008 and his M.Sc. degree in Information and Communication Technology (ICT) from the University of Agder (UiA), Norway in 2012. His Master thesis was awarded as the Best Master's thesis in ICT at UiA in 2012. His Ph.D. study was performed at the Department of ICT, UiA from Sept. 2012 to June 2016. He worked as a lecturer at the Department of Electrical and Information Engineering, University of Ruhuna from Aug. 2009 to Aug. 2010. His current research interest covers various areas of mobile and wireless communications, including reliability analysis, spectrum management, modeling and performance evaluation of communication networks especially cognitive radio networks.

Prøveforelesning og disputas finner sted i Rom C2 040, Campus Grimstad.

Dekan Michael Rygaard Hansen leder disputasen.

Tid for prøveforelesning: Onsdag 2. november 2016 kl 10:00

Oppgitt emne for prøveforelesning: “Hidden Markov Models and their application to fault-detection

Tid for disputas:Onsdag 2. november 2016 kl 12:00

Tittel på avhandling: «Channel Access and Reliability Analysis in Cognitive Radio Networks»

Søk etter avhandlingen i AURA - Agder University Research Archive AURA - Agder University Research Archive, som er et digitalt arkiv for vitenskapelige artikler, avhandlinger og masteroppgaver fra ansatte og studenter ved Universitetet i Agder. AURA blir jevnlig oppdatert.

Opponenter:

Førsteopponent: Professor Hans-Peter Schwefel, Aalborg University

Annenopponent:Professor Juan José Alcaraz Espin, Technical University of Cartagena

Bedømmelseskomitéen er ledet av førsteamanuensis Morten Goodwin, UiA

Veiledere i doktorgradsarbeidet var professor Frank Y. Li, UiA og Vicent PlaUniversitat Politècnica de València