Bluetooth is a low cost, short-range radio technology that enables electronic devices to communicate wirelessly via ad-hoc networks. Different kinds of applications may run over these networks, some of these applications with particular Quality of Service (QoS) requirements. One such application could for instance be an Audio application which need data frames to be delivered at regular interval to work properly. The communication over Bluetooth links is totally controlled by one of the participating nodes. Since this node controls the traffic and thereby controls the QoS within the network its communicating behaviour is of great importance for maintaining QoS reservations. A central part in maintaining QoS reservations is the scheduler, which prioritises between different tasks to be done such as which device that is allowed to transmit next. There is no standardised way to implement the Bluetooth scheduler. However, a Bluetooth scheduler should be able to handle QoS reservations, maintain fairness among the participating nodes, and utilise the available bandwidth efficiently. Furthermore a key requirement in Bluetooth is simplicity, therefore a Bluetooth scheduling algorithm should be of low complexity. This master thesis presents a new patented solution for an intra-piconet scheduling algorithm that is capable of maintaining QoS reservation, while being fair and also meet the low complexity requirement. This algorithm is presented in detail in the thesis and has been implemented in an ns2- based Bluetooth simulator. Simulations in this simulator are presented that verifies the scheduling algorithms functionality. / Bluetooth är en standard för trådlös ad-hoc kommunikation. Denna standard definierar i antalet noder begränsade nätverk (piconet) som kan kopplas samman till större nätverk (scatternet). Många olika typer av applikationer kan tänkas använda dessa nätverk, vissa av dessa med speciella krav på Quality of Service (QoS). Ett exempel så en dylik applikation är ljudöverföringar som kräver att data överförs med jämna mellanrum för att kunna fungera tillfredställande. Kommunikationen över ett Bluetooth-piconet kontrolleras helt av en av de deltagande enheterna. Eftersom denna enhet kontrollerar trafiken kontrollerar den också upprätthållandet av QoS reservationerna. En central del i detta upprätthållande är schemaläggaren, som är den del i en Bluetoothenhet som prioriterar mellan olika saker som ska utföras. Ett exempel på en sådan prioritering kan vara vilken enhet i nätverket som ska få kommunicera härnäst. Bluetooth standarden beskriver inte hur denna schemaläggare ska implementeras. Grundläggande krav på en Bluetooth schemaläggare är att den ska kunna hantera och upprätthålla QoS reservationer samtidigt som den delar den befintliga kapaciteten på ett rättvist och effektivt sätt mellan de deltagande enheterna. Vidare bör den ha en låg komplexitet eftersom enkelhet är ett krav på alla delar i ett Bluetoothsystem. Detta examensarbete presenterar en ny patenterad algoritm för schemaläggning i begränsade Bluetoothnät som är kapabel att upprätthålla QoS-reservationer, samtidigt som den distribuerar den tillgängliga kapaciteten på ett rättvist sätt. Algoritmen möter också upp till kravet på låg komplexitet. Rapporten innehåller vidare simuleringar av algoritmens funktion, dessa har utförts i en ns2-baserad Bluetooth miljö och verifierar algoritmens funktionalitet.

Hur vi människor kommer att leva i framtiden kan kraftigt påverkas utav konceptet Internet of Things. IoT erbjuder unika möjligheter för att hjälpa oss människor att automatisera och förenkla vissa ärenden. Även om koncpetet har funnits ett tag så har man fortfarande vilseledda åsikter kring potentialen med IoT. Det intressanta med konceptet och vad som enligt mig är den fundamentala grunden för IoT är självaste kommunikationen. Men hur går kommunikation till? Ett flertal IoT kommunikationsprotokoll har utvecklats för att försöka förbättra kommunikationen mellan två och flera smarta enheter. Eftersom det finns ett par olika kommunikationsprotokoll så är målet för denna studie att utvärdera och undersöka prestandan för befintliga applikations lagrade kommunikationsprotokoll. En litteraturrecension görs för att identifiera och få en djupare förståelse för deras unika egenskaper som skiljer protokollen åt. Alla protokoll som tas upp i denna rapport kommer inte att undersökas och valet av vilka protokoll som ska inspekteras närmare gjordes genom en jämförande analys där faktorer som kommunikationsmetod och begränsningen av nyttolast storleken beaktades. Latens, genomströmning och skalbarheten är de prestandafaktorerna som bedöms för de protokoll som valts för en närmare inspektion. Resultaten av dessa tester används för att dra slutsatser om lämpligheten för varje protokoll. Efter en omfattande utvärdering baserat på de experimenten som gjorts under projektets gång så drar denna rapport slutsatsen att MQTT och CoAP är de mest lämpliga protokollen för allmänna IoT-applikationer på grund av deras lätta, effektiva och skalbara natur. / The Internet of Things is a concept that has gained widespread attention and adaptation all around the world, but few people really do understand how it works and what it really is. The concept revolutionized the way we interact with our surroundings, it revolves around connectivity between smart devices and how they communicate with other devices or with humans. To ensure effective communication, a set of application layered protocols has been developed. These protocols are designed to be beneficial in certain areas, which is why the objective for this study has been to evaluate and examine the performance of existing application communication protocols. A thorough literature review is conducted to identify and gain a deeper understanding of their unique characteristics and features for some protocols that exist and are used today. All protocols brought up in this thesis will not be examined and choosing which protocols to inspect further was done by doing a comparative analysis where factors such as, communication method and payload limit size were taken into consideration. Performance assessment was done for the protocols that qualified, where factors like latency, throughput, and scalability were measured. The results of these tests are used to draw conclusions about the suitability of each protocol. After a comprehensive evaluation based on experiments with simulations and literature reviews, this thesis concludes that MQTT and CoAP as the most suitable protocols for general IoT applications due to their lightweight, efficient, and scalable nature.

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / This paper presents a model for Quality of Service (QoS) management in a mix of fixed Ground Station (GS) and ad-hoc telemetry networks, and introduces an enhanced clustering scheme that jointly optimizes the performance of the network using multiple distance measures based on the location of the wireless nodes and the traffic level. It also demonstrates that a "power" performance measure is an effective tool for modeling and managing QoS in Mixed Networks. Simulation results show that significant QoS performance improvements can be obtained and maintained even under severe traffic conditions.

Distributed multimedia supports a symbiotic infotainment duality, i.e. the ability to transfer information to the user, yet also provide the user with a level of satisfaction. As multimedia is ultimately produced for the education and / or enjoyment of viewers, the user’s-perspective concerning the presentation quality is surely of equal importance as objective Quality of Service (QoS) technical parameters, to defining distributed multimedia quality. In order to extensively measure the user-perspective of multimedia video quality, we introduce an extended model of distributed multimedia quality that segregates quality into three discrete levels: the network-level, the media-level and content-level, using two distinct quality perspectives: the user-perspective and the technical-perspective. Since experimental questionnaires do not provide continuous monitoring of user attention, eye tracking was used in our study in order to provide a better understanding of the role that the human element plays in the reception, analysis and synthesis of multimedia data. Results showed that video content adaptation, results in disparity in user video eye-paths when: i) no single / obvious point of focus exists; or ii) when the point of attention changes dramatically. Accordingly, appropriate technical- and user-perspective parameter adaptation is implemented, for all quality abstractions of our model, i.e. network-level (via simulated delay and jitter), media-level (via a technical- and user-perspective manipulated region-of-interest attentive display) and content-level (via display-type and video clip-type). Our work has shown that user perception of distributed multimedia quality cannot be achieved by means of purely technical-perspective QoS parameter adaptation.

In the past decades, mobile traffic generated by devices such as smartphones, iphones, laptops and mobile gateways has been growing rapidly. While traditional direct connection techniques evolve to provide better access to the Internet, a new type of wireless network, mobile ad hoc network (MANET), has emerged. A MANET differs from a direct connection network in the way that it is multi-hopping and self-organizing and thus able to operate without the help of prefixed infrastructures. However, challenges such dynamic topology, unreliable wireless links and resource constraints impede the wide applications of MANETs. Routing in a MANET is complex because it has to react efficiently to unfavourable conditions and support traditional IP services. In addition, Quality of Service (QoS) provision is required to support the rapid growth of video in mobile traffic. As a consequence, tremendous efforts have been devoted to the design of QoS routing in MANETs, leading to the emergence of a number of QoS support techniques. However, the application independent nature of QoS routing protocols results in the absence of a one-for-all solution for MANETs. Meanwhile, the relative importance of QoS metrics in real applications is not considered in many studies. A Best Effort QoS support (BEQoS) routing model which evaluates and ranks alternative routing protocols by considering the relative importance of multiple QoS metrics is proposed in this thesis. BEQoS has two algorithms, SAW-AHP and FPP for different scenarios. The former is suitable for cases where uncertainty factors such as standard deviation can be neglected while the latter considers uncertainty of the problems. SAW-AHP is a combination of Simple Additive Weighting and Analytic Hierarchical Process in which the decision maker or network operator is firstly required to assign his/her preference of metrics with a specific number according to given rules. The comparison matrices are composed accordingly, based on which the synthetic weights for alternatives are gained. The one with the highest weight is the optimal protocol among all alternatives. The reliability and efficiency of SAW-AHP are validated through simulations. An integrated architecture, using evaluation results of SAW-AHP is proposed which incorporates the ad hoc technology into the existing WLAN and therefore provides a solution for the last mile access problems. The protocol selection induced cost and gains are also discussed. The thesis concludes by describing the potential application area of the proposed method. Fuzzy SAW-AHP is extended to accommodate the vagueness of the decision maker and complexity of problems such as standard deviation in simulations. The fuzzy triangular numbers are used to substitute the crisp numbers in comparison matrices in traditional AHP. Fuzzy Preference Programming (FPP) is employed to obtain the crisp synthetic weight for alternatives based on which they are ranked. The reliability and efficiency of SAW-FPP are demonstrated by simulations.

In the recent years, the mobile gaming has been tremendously increased because of its enormous entertainment features. Mobile cloud gaming is a promising technology that overcomes the implicit restrictions such as computational capacity and limited battery life. GamingAnywhere is an open source cloud gaming system which is used in this thesis to measure the Quality of service of mobile cloud gaming. The aim of the thesis is to measure the QoS used in GamingAnywhere for mobile cloud gaming. Games are streamed from the server to the mobile client. In our study, QoS is measured using Differentiated Service (DiffServ) architecture for the traffic shaping. The research method is carried out using an experimental testbed. Dummynet is used for traffic shaping. Performance is measured in terms of bitrate, packet loss, jitter, and frame rate. Different resolutions of the game are considered in our empirical research and our results show that the framerate and bitrate have increased with the impact of network delay. / <p>Ganesh Grandhi: +46767671612</p>

The overarching goal of this thesis is to investigate network architectures, and find the trade-off between low overall energy use and maintaining the level of quality of service (QoS), or even improve it. The ubiquitous wireless communications environment supports the exploration of different network architectures and techniques, the so-called heterogeneous network. Two kinds of heterogeneous architectures are considered: a combined cellular and femtocell network and a combined cellular, femtocell and Wireless Local Area Network(WLAN) network. This thesis concludes that the investigated heterogeneous networks can significantly reduce the overall power consumption, depending on the uptake of femtocells and WLANs. Also, QoS remains high when the power consumption drops. The main energy saving is from reducing the macrocell base station embodied and operational energy. When QoS is evaluated based on the combined cellular and femtocell architecture, it is suggested that use of resource scheduling for femtocells within the macrocell is crucial since femtocell performance is affected significantly by interference when installed in a co-channel system. Additionally, the femtocell transmission power mode is investigated using either variable power level or a fixed power level. To achieve both energy efficiency and QoS, the choice of system configurations should change according to the density of the femtocell deployment. When combining deployment of femtocells with WLANs, more users are able to experience a higher QoS. Due to increasing of data traffic and smartphone usage in the future, WLANs are more important for offloading data from the macrocell, reducing power consumption and also increasing the bandwidth. The localised heterogeneous network is a promising technique for achieving power efficiency and a high QoS system.

Applications with timing requirements, such as multimedia and live multi-user interaction, are becoming more prevalent in wide area networks. The desire to provide more predictable performance for such applications in packet switched wide area networks is evident in the channel management provided by Asynchronous Transfer Mode (ATM) networks and in the extensions to the Internet protocols proposed by the Internet Engineering Task Force (IETF) working groups on integrated and differentiated service. The ability to provide guarantees on the performance of traffic flows, such as packet delay and loss characteristics, relies on an accurate model of the traffic arrival and service at each node in the network. This thesis surveys the work in bounding packet delay based on various proposed queuing disciplines and proposes a method for more accurately defining the traffic arrival and worst case backlog experienced by packets. The methods are applied to the first in first out (FIFO) queuing discipline to define equations for determining the worst case backlog and queuing delay in multihop networks. Simulation results show a significant improvement in the accuracy of the delay bounds over existing bounds published in the literature. An improvement of two orders of magnitude can be realised for a ten hop path and the improvement increases exponentially with the length of the path for variable rate network traffic. The equations derived in the thesis also take into consideration the effect of jitter on delay, thereby removing the requirement for rate controllers or traffic shaping within the network. In addition to providing more accurate delay bounds, the problem of providing fault tolerance to channels with guaranteed quality of service (QoS) is also explored. This thesis introduces a method for interleaving resource requirements of backup channels to reduce the overall resource reservations that are required to provide guaranteed fault recovery with the same QoS as the original failed channel. An algorithm for selecting recovery paths that can meet a channel's QoS requirements during recovery is also introduced. / Thesis (Ph.D.)--Computer Science, 2003.

Στόχος της διπλωματικής αυτής είναι η παρουσίαση τεχνικών στα πλαίσια της Διαχείρισης Ραδιοπόρων με σκοπό την βελτιστοποίηση της παρεχόμενης υπηρεσίας (QoS), σε δίκτυα κινητής τηλεφωνίας 3ης γενιάς. Στο πρώτο κεφάλαιο γίνεται μια εισαγωγή στα δίκτυα κινητών επικοινωνιών και μια ιστορική αναδρομή. Στη συνέχεια παρουσιάζεται μια επισκόπηση της τεχνολογίας του CDMA και γίνεται καταγραφή και ανάλυση τεχνικών RRM. Στο σύστημα UMTS είναι αφιερωμένο ολόκληρο το δεύτερο κεφάλαιο. Το UMTS εξετάζεται από πλευράς αρχιτεκτονικής και πρωτοκόλλων. Το handover ως βασικό στοιχείο της Διαχείρισης Ραδιοπόρων μελετάται στο τρίτο κεφάλαιο. Ιδιαίτερη αναφορά και μελέτη γίνεται για το Soft Handover, ως το βασικό Handover του συστήματος WCDMA, που χρησιμοποιείται προκειμένου να διασφαλιστεί η απαιτούμενη υπηρεσία. Στο τέταρτο κεφάλαιο περνάμε στην multicast μετάδοση. Σε αυτή την περίπτωση εξετάζουμε την αποδοτική επιλογή καναλιού (Efficient Channel Selection), με στόχο την διασφάλιση του ίδιου QoS για όσο το δυνατόν περισσότερους χρήστες κάνοντας την καλύτερη δυνατή διαχείριση των πόρων του συστήματος. Τέλος το πέμπτο κεφάλαιο αφιερώνεται στην συνολική παρουσίαση των συμπερασμάτων που έχουν εξαχθεί στα προηγούμενα κεφάλαια. / -

Τα ασύρματα δίκτυα έχουν αρχίσει να κατακλύζουν την παγκόσμια αγορά υψηλής τεχνολογίας. Αυτό μπορεί να αποδοθεί στα πολλά πλεονεκτήματα που προσφέρουν καθώς και στο ότι πλέον τα περισσότερα προβλήματα που είχαν στο παρελθόν έχουν αντιμετωπιστεί σε πολύ μεγάλο βαθμό. Ακόμα προσφέρουν ιδιαίτερη ευκολία στην ανάπτυξη λύσεων σε ειδικά προβλήματα. Ωστόσο, όλα τα ασύρματα δίκτυα υιοθετούν κάποια μέθοδο ασφάλειας, η οποία έχει κάποιον αντίκτυπο στις επιδόσεις του δικτύου. Σκοπός της παρούσης εργασίας είναι να μελετηθεί η επιβάρυνση που επέρχεται σε ένα ασύρματο δίκτυο με τη χρήση διαφόρων επιπέδων ασφάλειας. Η μέθοδος και το μέγεθος της ασφάλειας αυτής πρέπει να είναι ισορροπημένη, προκειμένου όπως θα αναλυθεί και στη συνέχεια, και να διασφαλιστεί και η καλή συμπεριφορά του δικτύου αλλά και η ακεραιότητα των προσωπικών δεδομένων. Τα προβλήματα που εμπλέκονται είναι αυτή της δρομολόγησης με χρήση κόμβων περιορισμένης μνήμης και υπολογιστικής ισχύος. Δηλαδή, συσκευές οι οποίες δεν έχουν πλεονασμό υπολογιστικής ισχύος αλλά ούτε και μνήμης, καλούνται να κρυπτογραφήσουν, να αποκρυπτογραφήσουν ή να αναμεταδώσουν πακέτα προς τον προορισμό τους. Η μεθοδολογία αντιμετώπισης του προβλήματος που ακλουθείται είναι αυτή των εξομοιώσεων. Ο λόγος για αυτήν την επιλογή είναι ότι μας προσφέρει τη δυνατότητα να μελετήσουμε πληθώρα περιπτώσεων και στη συνέχεια με χρήση αναλυτικών μεθόδων μας δίνεται η δυνατότητα να αναλύσουμε τα αποτελέσματα που προκύπτουν. / -