Approved for public release, distribution is unlimited / With the rapidly growing demand for portable devices such as laptops, handheld computers and Personal Digital Assistants (PDAs) with wireless networking capabilities, the need for reliable wireless data network communication has also increased. Just like in mobile voice communication, users demand uninterrupted, secure wireless data communication as they move from place to place. Mobile IP satisfies some of these demands - it enables mobile devices with fixed IP addresses to be permanently reachable even as their point of attachment to the network changes. This allows for routing of data packets to and from the mobile device irrespective of its location on the network. While uninterrupted data flow can be achieved with Mobile IP, it introduces additional security vulnerabilities, including data privacy, data integrity and authentication. The goal of this thesis is to investigate such vulnerabilities and explore implementations to overcome them. / Civilian, National Science Foundation

Findings of this research work provide clear understanding of why organizationaltechnology(Network technology) adoption decision makers decide to recommend or notrecommend an Internet Protocol migration(adoption of the latest protocol), or a migrationfrom Ipv4 to IPv6/ or adoption of IPv6, to their organizations. A meticulous review ofliterature on the practice of various organizations technology adoption process served as abase for developing relevant research questions and corresponding hypothesis. The researchhypothesis was developed to examine organization‟s technology (Network technology)adoption decision maker‟s perception of IPv6: quality of service, auto configurationcapability, security, mobility, address abundance and cost effectiveness and its effect on theirdecision.The study result indicated that network expert‟s decision to recommend a new networktechnology adoption, specifically, internet protocol migration from IPv4 to IPv6 is highlyinfluenced by their perception of the factors listed in the previous paragraph, thereforenetwork expert‟s perception of the aforementioned factors are instrumental for their decisionof recommending whether to encourage the internet protocol migration. It is also implied thatmanagers at top level can make a technology adoption or migration decision based on therecommendation from the experts already knowing that their decision is highly influenced bytheir perception of capabilities and functionality of the new IP (IPv6). In addition to theapparent contribution of this study to organizations that fall in to the category of organization,where this study was conducted, the result of this study also helps different organizationsengaged in other kinds of business activity, such as: network infrastructure manufacturersand application developers by providing essential information regarding which functionalitiesand capabilities are playing a major role for organization‟s choice for a certain networkinfrastructure. / Program: Masterutbildning i Informatik

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 2010

Internet protocol TV (IPTV) is predicted to be the key technology winner in the future. Efforts to accelerate the deployment of IPTV centralized model which is combined of VHO, encoders, controller, access network and Home network. Regardless of whether the network is delivering live TV, VOD, or Time-shift TV, all content and network traffic resulting from subscriber requests must traverse the entire network from the super-headend all the way to each subscriber's Set-Top Box (STB).IPTV services require very stringent QoS guarantees When IPTV traffic shares the network resources with other traffic like data and voice, how to ensure their QoS and efficiently utilize the network resources is a key and challenging issue. For QoS measured in the network-centric terms of delay jitter, packet losses and bounds on delay. The main focus of this thesis is on the optimized bandwidth allocation and smooth datatransmission. The proposed traffic model for smooth delivering video service IPTV network with its QoS performance evaluation. According to Maglaris et al [5] First, analyze the coding bit rate of a single video source. Various statistical quantities are derived from bit rate data collected with a conditional replenishment inter frame coding scheme. Two correlated Markov process models (one in discrete time and one incontinuous time) are shown to fit the experimental data and are used to model the input rates of several independent sources into a statistical multiplexer. Preventive control mechanism which is to be include CAC, traffic policing used for traffic control.QoS has been evaluated of common bandwidth scheduler( FIFO) by use fluid models with Markovian queuing method and analysis the result by using simulator andanalytically, Which is measured the performance of the packet loss, overflow and mean waiting time among the network users.

Internet protocol TV (IPTV) is predicted to be the key technology winner in the future. Efforts to accelerate the deployment of IPTV centralized model which is combined of VHO, encoders, controller, access network and Home network. Regardless of whether the network is delivering live TV, VOD, or Time-shift TV, all content and network traffic resulting from subscriber requests must traverse the entire network from the super-headend all the way to each subscriber's Set-Top Box (STB). IPTV services require very stringent QoS guarantees When IPTV traffic shares the network resources with other traffic like data and voice, how to ensure their QoS and efficiently utilize the network resources is a key and challenging issue. For QoS measured in the network-centric terms of delay jitter, packet losses and bounds on delay. The main focus of this thesis is on the optimized bandwidth allocation and smooth data transmission. The proposed traffic model for smooth delivering video service IPTV network with its QoS performance evaluation. According to Maglaris et al [5] first, analyze the coding bit rate of a single video source. Various statistical quantities are derived from bit rate data collected with a conditional replenishment inter frame coding scheme. Two correlated Markov process models (one in discrete time and one in continuous time) are shown to fit the experimental data and are used to model the input rates of several independent sources into a statistical multiplexer. Preventive control mechanism which is to be including CAC, traffic policing used for traffic control. QoS has been evaluated of common bandwidth scheduler( FIFO) by use fluid models with Markovian queuing method and analysis the result by using simulator and analytically, Which is measured the performance of the packet loss, overflow and mean waiting time among the network users.

Over the past decade, the rapid developments and growth of information and communication technology (ICT) have triggered a new wave of customer service. This study utilizes the net-enable business innovation cycle theory with secondary data analysis to analyze the process and outcomes of the implementation of emerging technology, i.e., web-based application and voice over internet protocol (VoIP) for the case company, i.e., A Company. We investigate the characteristics and feature of the emerging technology including the web-based application and VoIP, identify the potential economic opportunity for the A Company, analyze the needed business innovation for its growth, and assess the potential value for its customer. The findings have the potential to contribute to the understanding of impacts occurring in the innovation associated with the implementation of the emerging technology for the A Company and offer rich insights for the company to exploit the economic opportunities, the needed business innovation, and the potential value for the customer. This approach also provides a systematic template that helps an organization to decide whether an emerging technology is worthy to implement.

Το έγγραφο είναι μια έρευνα του υποσυστήματος πολυμέσων διαδικτυακού πρωτοκόλλου και μια υλοποιήση ενός περιβάλλοντος προσομοίωσης, γνωστό ως testbed, που βασίζεται σε αυτό το πρωτόκολλο. Στην αρχή γίνεται μια εισαγωγή στην έννοια του IMS. Στο δεύτερο κεφάλαιο, περιγράφουμε τη γενική αρχιτεκτονική του IMS. Στο τρίτο κεφάλαιο, υπάρχει αναφορά στο επίπεδο σηματοδοσίας και όλα τα στοιχεία του. Στο τέταρτο κεφάλαιο περιγράφουμε τις υπηρεσίες που παρέχει το IMS και την αρχιτεκτονική του Open IMS Core που αποτελεί το περιβάλλον προσομοίωσής μας. Τέλος, αναλύουμε τα βήματα με σκοπό να εγκαταστήσουμε τον Open IMS Core ρησιμοποιώντας το λειτουργικό σύστημα Linux. / The script is a research of the Internet Protocol Multimedia Subsystem (IMS) and an implementation of a simulation environment, known as testbed and based on this protocol. In the beginning, there is an introduction to the meaning of IMS.In chapter two, we describe the general architecture of IMS. In chapter three, there is a reference to the signalling level and all of its elements. In chapter four we describe the services that IMS provides and the architecture of the Open IMS Core which is our simulation environment. Finally, we analyse the steps in order to install Open Ims Core using Linux operating system.

Thesis (M.Eng.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 63-65.

Το αντικείμενο της παρούσας διπλωματικής εργασίας είναι η μελέτη της ψηφιακής τηλεόρασης μέσω πρωτόκολλου Internet, γνωστής και ως IPTV (Internet Protocol TeleVision) με ιδιαίτερη εστίαση στον αποκωδικοποιητή που χρησιμοποιείται για την επίτευξη της τηλεοπτικής μετάδοσης. Αυτός ο αποκωδικοποιητής ονομάζεται Set-Top Box. Στην ουσία το IPTV είναι η μετάδοση τηλεοπτικού σήματος μέσω ευρυζωνικής σύνδεσης που χρησιμοποιεί το πρωτόκολλο IP μέσω ενός ιδιωτικού κλειστού δικτύου και όχι του δημοσίου Internet. Το IPTV θεωρείται το παρόν και το μέλλον όσον αφορά τα είδη τηλεόρασης καθώς ο χρήστης έχει την δυνατότητα για πρόσβαση σε τηλεοπτικά κανάλια με ψηφιακή εικόνα ενώ η δυνατότητα που παρέχουν οι on-demand υπηρεσίες για παρακολούθηση τηλεοπτικού περιεχομένου παντός τύπου την ώρα που επιθυμεί ο χρήστης καθιστά το «πακέτο» πολύ πιο ελκυστικό. Συγκεκριμένα, σε αυτή την διπλωματική εργασία, παρουσιάζεται αρχικά ο ορισμός της δικτυακής τηλεόρασης και γενικά όλων αυτών που συνέβαλλαν στην δημιουργία του IPTV. Κατόπιν γίνεται μια συνοπτική ιστορική αναδρομή στα γεγονότα που οδήγησαν στην μορφή του IPTV όπως την ξέρουμε σήμερα. Έπειτα συγκρίνεται το IPTV με το γνωστό μας Internet TV. Στην συνέχεια γίνεται μια γενική περιγραφή ενός δικτύου IPTV ενώ έπειτα εμβαθύνουμε περισσότερο καθώς περιγράφονται και τεχνικές λεπτομέρειες για ένα τέτοιο δίκτυο. Ακολούθως περιγράφονται οι κωδικοποιήσεις που πραγματοποιούνται αλλά και οι διάφορές τους. Επιπλέον γίνεται ιδιαίτερη αναφορά και ανάλυση στα διάφορα είδη των αποκωδικοποιητών (Set-Top Box) που χρησιμοποιούνται και επισημαίνονται οι διαφορές που έχουν στη δομή και στα χαρακτηριστικά τους. Τέλος γίνεται μια αναφορά στους παρόχους πακέτων IPTV στην Ελλάδα ενώ γίνεται και μια σύγκριση αυτών των πακέτων μεταξύ τους. / The theme of this particular thesis is the study of the digital television via Internet protocol, also known as IPTV (Internet Protocol TeleVision) with special focusing on the decoder which is used in order to achieve television broadcasting. This decoder is called Set-Top Box. Essentially, IPTV is the transmission of television signals over broadband which is using IP protocol through a closed private network and not the public Internet. IPTV is considered to be the present and the future regarding the types of television because the user has the ability to access TV channels with digital view, while the ability provided by on-demand services about watching every type of television content at every time the user wants makes the whole “package” much more attractive. Particularly, in this thesis, is firstly presented the definition of networking TV and generally of all these things which have contributed to the creation of IPTV. Following is a brief historical background to the events that led to the form of IPTV as we know it today. Afterwards, the IPTV is compared to the Internet TV, which is familiar to us. After that, a general description of an IPTV network is taking place and then we go further as technical details of such a network are described. Moreover, the encodings performed and their differences are mentioned. Additionally, there is much reporting and analysis in various types of decoders (Set-Top Box) used and marked the differences they have on their structure and their profile. Finally, there is a reference to IPTV packet providers in Greece and is happening a comparison among these packets.

Magister Scientiae - MSc / This thesis presents an analysis of the impact of node mobility on the quality of service for voice over Internet Protocol in wireless mesh networks. Voice traffic was simulated on such a mesh network to analyze the following performance metrics: delay, jitter, packet loss and throughput. Wireless mesh networks present interesting characteristics such as multi-hop routing, node mobility, and variable coverage that can impact on quality of service. A reasonable deployment scenario for a small organizational network, for either urban or rural deployment, is considered with three wireless mesh network scenarios, each with 26 mesh nodes. In the first scenario, all mesh nodes are stationary. In the second scenario, 10 nodes are mobile and 16 nodes are stationary. Finally, in the third scenario, all mesh nodes are mobile. The mesh nodes are simulated to move at a walking speed of 1.3m per second. The results show that node mobility can increase packet loss, delay, and jitter. However, the results also show that wireless mesh networks can provide acceptable quality of service, providing that there is little or no background traffic generated by other applications. In particular, the results demonstrate that jitter across all scenarios remains within humanacceptable tolerances. It is therefore recommended that voice over Internet Protocol implementations on wireless mesh networks with background traffic be supported by quality of service standards; otherwise they can lead to service delivery failures. On the other hand, voice-only esh networks, even with mobile nodes, offer an attractive alternative voice over Internet Protocol platform. / South Africa