Current FPGA technology has advanced to the point that useful embedded SoPCs can now be designed. The Real Time Processor (RTP) project at Brigham Young University leverages the advances in FPGA technology with a system architecture that is customizable to specific applications. A simple real-time processor has been designed to provide support for a hardware-assisted real-time operating system providing fast context switches. As part of the hardware RTOS, the following have been implemented in hardware: scheduler, register banks, mutex, semaphore, queue, interrupts, event, and others. A novel circuit called the Task-Resource Matrix has been created to allow fast inter/intra processor communication and synchronization.

Given the current developments and advances in the scientific and technological aspects of human knowledge and introducing new approaches in various fields of telecommunication technologies and industries, there has been an increasing growth in its players¿ plans and a positive change in their outlooks in order to achieve the target of "anywhere and anytime access". Recent developments of WiMAX (Worldwide interoperability for Microwave Access) networks, as a sign of increasing needs and demands for new telecommunication services and capabilities, have led to revolutions in global telecommunication which should be perceived properly in terms of the commercial and technical aspects in order to enjoy the new opportunities. Most experts believe that WiMAX technology is a preliminary step to develop Fourth Generation networks known as 4G technologies. It has not only succeeded in the utilization of several of the latest telecommunication techniques in the form of unique practical standards, but also paved the way for the quantitative and qualitative developments of high-speed broadband access. IEEE 802.16 Standard introduces several advantages, and one of them is the support for Quality of Services (QoS) at the Media Access Control (MAC) level. For these purposes, the standard defines several scheduling classes at MAC layer to treat service flow in a different way, depending on QoS requirements. In this thesis, we have proposed a new QoS framework for Point-to-Multi Point (PMP) 802.16 systems operating in Time Division Duplexing (TDD) mode over a WirelessMAN-OFDM physical layer. The proposed framework consists of a Call Admission Control (CAC) module and a scheduling scheme for the uplink traffic as well as a simple frame allocation scheme. The proposed CAC module interacts with the uplink scheduler status and it makes its decision based on the scheduler queue status; on the other hand, the proposed scheduling scheme for the uplink traffic aims to support realtime flows and adapts the frame-by-frame allocations to the current needs of the connections, with respect to the grants boundaries fixed by the CAC module. Extensive OPNET simulation demonstrates the effectiveness of the proposed architecture.

The support of multimedia traffic over IEEE 802.11 wireless local area networks (WLANs) has recently received considerable attention. This dissertation has proposed a new framework that provides efficient channel access, service differentiation and statistical QoS guarantees in the enhanced distributed channel access (EDCA) protocol of IEEE 802.11e. In the first part of the dissertation, the new framework to provide QoS support in IEEE 802.11e is presented. The framework uses three independent components, namely, a core MAC layer, a scheduler, and an admission control. The core MAC layer concentrates on the channel access mechanism to improve the overall system efficiency. The scheduler provides service differentiation according to the weights assigned to each Access Category (AC). The admission control provides statistical QoS guarantees. The core MAC layer developed in this dissertation employs a P-Persistent based MAC protocol. A weight-based fair scheduler to obtain throughput service differentiation at each node has been used. In wireless LANs (WLANs), the MAC protocol is the main element that determines the efficiency of sharing the limited communication bandwidth of the wireless channel. In the second part of the dissertation, analytical Markov chain models for the P-Persistent 802.11 MAC protocol under unsaturated load conditions with heterogeneous loads are developed. The Markov models provide closed-form formulas for calculating the packet service time, the packet end-to-end delay, and the channel capacity in the unsaturated load conditions. The accuracy of the models has been validated by extensive NS2 simulation tests and the models are shown to give accurate results. In the final part of the dissertation, the admission control mechanism is developed and evaluated. The analytical model for P-Persistent 802.11 is used to develop a measurement-assisted model-based admission control. The proposed admission control mechanism uses delay as an admission criterion. Both distributed and centralized admission control schemes are developed and the performance results show that both schemes perform very efficiently in providing the QoS guarantees. Since the distributed admission scheme control does not have a complete state information of the WLAN, its performance is generally inferior to the centralized admission control scheme. The detailed performance results using the NS2 simulator have demonstrated the effectiveness of the proposed framework. Compared to 802.11e EDCA, the scheduler consistently achieved the desired throughput differentiation and easy tuning. The core MAC layer achieved better delays in terms of channel access, average packet service time and end-to-end delay. It also achieved higher system throughput than EDCA for any given service differentiation ratio. The admission control provided the desired statistical QoS guarantees.

The master thesis deals with the techniques to prevent computer system from computational overloading due to excessive frequency of interruptions. The goal is to document the effect of interupts on a selected computing platform containing the ARM Cortex-M4 processor core. The work describes and implements possible software techniques that reduce the impact of consequences of overload due to excessive interruption frequency. At the same time the work verifies and compares the effectiveness of the particular implemented techniques by appropriate set of experiments.

Mobile phone tracking is the ascertaining of the position or location of a mobile phone when moving from one place to another place. Location Based Services Solutions include Mobile positioning system that can be used for a wide array of consumer-demand services like search, mapping, navigation, road transport traffic management and emergency-call positioning. The Mobile Positioning System (MPS) supports complementary positioning methods for 2G, 3G and 4G/LTE (Long Term Evolution) networks. Mobile phone is popularly known as an UE (User Equipment) in LTE. A prototype method of live trajectory estimation for massive UE in LTE network has been proposed in this thesis work. RSRP (Reference Signal Received Power) values and TA(Timing Advance) values are part of LTE events for UE. These specific LTE events can be streamed to a system from eNodeB of LTE in real time by activating measurements on UEs in the network. AoA (Angle of Arrival) and TA values are used to estimate the UE position. AoA calculation is performed using RSRP values. The calculated UE positions are filtered using Particle Filter(PF) to estimate trajectory. To obtain live trajectory estimation for massive UEs, the LTE event streamer is modelled to produce several task units with events data for massive UEs. The task level modelled data structures are scheduled across Arm Cortex A15 based MPcore, with multiple threads. Finally, with massive UE live trajectory estimation, IMSI (International mobile subscriber identity) is used to maintain hidden markov requirements of particle filter functionality while maintaining load balance for 4 Arm A15 cores. This is proved by serial and parallel performance engineering. Future work is proposed for Decentralized task level scheduling with hash function for IMSI with extension of cores and Concentric circles method for AoA accuracy. / Mobiltelefoners positionering är välfungerande för positionslokalisering av mobiltelefoner när de rör sig från en plats till en annan. Lokaliseringstjänsterna inkluderar mobil positionering system som kan användas till en mängd olika kundbehovs tjänster som sökning av position, position i kartor, navigering, vägtransporters trafik managering och nödsituationssamtal med positionering. Mobil positions system (MPS) stödjer komplementär positions metoder för 2G, 3G och 4G/LTE (Long Term Evolution) nätverk. Mobiltelefoner är populärt känd som UE (User Equipment) inom LTE. En prototypmetod med verkliga rörelsers estimering för massiv UE i LTE nätverk har blivit föreslagen för detta examens arbete. RSRP (Reference Signal Received Power) värden och TA (Timing Advance) värden är del av LTE händelser för UE. Dessa specifika LTE event kan strömmas till ett system från eNodeB del av LTE, i realtid genom aktivering av mätningar på UEar i nätverk. AoA (Angel of Arrival) och TA värden är använt för att beräkna UEs position. AoA beräkningar är genomförda genom användandet av RSRP värden. Den kalkylerade UE positionen är filtrerad genom användande av Particle Filter (PF) för att estimera rörelsen. För att identifiera verkliga rörelser, beräkningar för massiva UEs, LTE event streamer är modulerad att producera flera uppgifts enheter med event data från massiva UEar. De tasks modulerade data strukturerna är planerade över Arm Cortex A15 baserade MPcore, med multipla trådar. Slutligen, med massiva UE verkliga rörelser, beräkningar med IMSI(International mobile subscriber identity) är använt av den Hidden Markov kraven i Particle Filter’s funktionalitet medans kravet att underhålla last balansen för 4 Arm A15 kärnor. Detta är utfört genom seriell och parallell prestanda teknik. Framtida arbeten för decentraliserade task nivå skedulering med hash funktion för IMSI med utökning av kärnor och Concentric circles metod för AoA noggrannhet.

Cette thèse CIFRE s’inscrit dans le cadre d’une collaboration entre Acta-Mobilier, fabricant de façades laquées haut de gamme, et le Centre de Recherche en Automatique Nancy. L’idée est de tirer parti du concept de Système Contrôlé par le Produit dans un environnement industriel perturbé par de nombreuses boucles de production et par un taux de reprises (non-qualités) non négligeable engendrant des pertes de pièces, le non-respect des délais, des charges de travail instables, etc… le lien impossible entre le produit et un identifiant infotronique rendant en plus la traçabilité difficile. Les travaux sur l’ordonnancement et son optimisation sont freinés par ces perturbations sur la chaîne de production qui rendent les plannings intenables. Le traitement prioritaire des pièces défectueuses permet d’assurer un taux de service qui reste remarquable au regard du pourcentage de pièces à réparer. Mais cela engendre aussi des pertes de pièces qui empêchent la livraison complète de la commande. La problématique scientifique s’articule autour du pilotage des flux dans un contexte de production perturbé par les reprises et de la maîtrise de la qualité en évaluant son impact sur l’engorgement. L’enjeu de maîtrise de la qualité a été abordé à l’aide de réseaux de neurones capables de prévoir l’apparition du défaut auquel ils sont dédiés en fonction des paramètres de production et environnementaux. Cette anticipation permet de proposer une alternative de programme à utiliser ou à reporter la planification de la tâche. L’adaptation du modèle de prévision aux dérives du modèle physique au comportement considéré comme nerveux est réalisée « en-ligne » à l’aide de cartes de contrôle qui permettent de détecter la dérive et sa date de début. Malgré cette simplification des flux, le pilotage reste complexe en raison des boucles normales de production et des non qualités résiduelles. Il existe différents états de saturation du système pour lesquels la règle de pilotage la plus adaptée n’est pas toujours la même. Cette analyse est présentée sous forme de cartographie en deux dimensions dont chacun des axes présente un indicateur clé du taux de non-qualité et/ou de la perturbation des flux. Même si, contrairement aux algorithmes, la règle de pilotage la mieux adaptée ne sera pas toujours mise en évidence, cette cartographie présente d’autres avantages tels que la simplification du pilotage, la possibilité pour tous les utilisateurs d’avoir l’information importante sur l’état de l’atelier en un coup d’oeil, ou encore la nécessité d’homogénéisation sur la globalité de l’unité de production. Dans ce contexte, le container intelligent offre des perspectives intéressantes avec la volonté de tracer un groupe de produits ayant la même gamme de fabrication plutôt que des produits un à un, de partager des informations telles que sa date de livraison, son degré d’urgence, de connaître quels chemins ils doivent emprunter dans l’atelier et quelles sont les alternatives possibles ou encore de communiquer avec les machines et les autres systèmes dont celui de prévision de la qualité et retenir des informations au fil de la fabrication des produits. Le système proposé est donc interactif ou le conteneur est au coeur de la décision. Il signale sa présence au système d’ordonnancement seulement si les conditions qualité sont réunies, permettant ainsi de simplifier son travail autorisant alors un simple algorithme traditionnel de programmation linéaire à réaliser cette tâche particulièrement compliquée au premier abord. C’est en revanche à la charge de l’ordonnanceur de s’assurer de la règle de pilotage à utiliser et de demander les informations correspondantes aux lots disponibles. La contribution de cette thèse est donc une méthodologie de simplification de problèmes complexes par une répartition des tâches entre différents sous-systèmes acteurs appliquée au cas d’une entreprise de fabrication de façades de cuisine laquées haut de gamme / Centre de Recherche en Automatique de Nancy. The idea is to take advantage of Product Driven System in an industrial environment disturbed by many loops and a rework rate (non quality) causing significant loss of products, non-compliance deadlines, unstable workloads, etc ... impossible link between the product and identifying infotronic lead to more difficult traceability. Work on scheduling and optimization are hampered by these disturbances on the production line that make them untenable schedules. Priority processing on defective products ensures a service rate that remains outstanding compared to the percentage of products to repair. But it also leads to loss of products that prevent the full delivery of the order. The scientific problem revolves around the control of flow in a production context disturbed by the loops and the quality level by assessing its impact on congestion. The quality-control issue has been addressed by using neural networks that can predict the occurrence of the defect to which they are dedicated from production and environmental parameters. This anticipation allows us to offer a program alternative to use or to plan to postpone the task. The adaptation of the forecasting model to the drift of the physical model with a behavior regarded as nervous is made "on line" using control charts that detect drift and its start date. Despite this simplification of flows, the flow control remains complex due to normal production loops and residual nonqualities. There are different system saturation states for which the most suitable control rule is not always the same. This analysis is presented in a two-dimensional mapping which each axis has a key indicator on non-quality rate and / or disruption of flows. Although, unlike algorithms, the most suitable control rule will not always be highlighted, this mapping has other advantages such as the simplification of the control, the ability for all users to have important information about the workshop state, or the need for homogenization of the global state of the production unit. In this context, the intelligent container offers interesting perspectives with the will to trace a group of products with the same rooting sheet rather than products one by one, to share information such as its delivery date, the urgency degree, to know what paths they should take and what are the possible alternatives or to communicate with other machines and systems including the quality forecasting system and retain information over the manufacture of the products. The proposed system is so interactive where container is at the heart of the decision. It reported his presence to scheduling system only if the quality system requirements are met, and simplify this work while allowing a traditional linear algorithm to achieve this task seen as particularly complicated at first. It is however the responsibility of the scheduler to ensure the pilot rule to use and request the relevant information available to the lots. The contribution of this thesis is a methodology to simplify complex problems by a division of work between different subsystems actors applied to the case of a manufacturer of high-finished lacquered panels

IEEE 802.16 是一支援都會型無線網路的協定，IEEE 802.16支援PMP模式(點對多點)和網狀模式兩種。在網狀模式中，所有節點的構成仿如ad-hoc方式，並依據在控制性子框中的排程資訊來計算下次遞送時間。在資料傳送之前，會有一段設定連線的時間。這段時間，每一個節點都必須跟鄰節點競爭，以取得廣播它的排程資訊給鄰節點的機會。這樣的行為跟它過去的歷史無關。換句話說，它具有”時間同質性”而適合以隨機程序來模擬。在這篇論文中，我們將用排隊程序來建立排程行為的模型，然後以馬可夫鏈來估計它的平均延遲時間，也就是一節點持續地競爭直到贏為止的這段等待時間。 / The IEEE 802.16 standard is a protocol for wireless metropolitan networks. IEEE 802.16 MAC protocol supports both of PMP (point to multipoint) and Mesh mode. In the mesh mode, all nodes are organized in a fashion similar ad-hoc and calculate their next transmission time based on the scheduling information performed in the control subframe. Before data transmission for a certain node, there is a period of time to setup the connection. During this period, each node has to compete with each other for the opportunity to advertise scheduling messages to its neighbors. This behavior does not depend on past history. In other words, it is a “Time Homogeneous” and suitable for being modeled by stochastic process. In this thesis, we will model this scheduling behavior by queuing process, and apply the Markov Chain to estimate its average delay time which a node keep waiting until it win the competition.

This thesis addresses the problem of building a Cognitive Radio that has the ability to interact with human users in a better way by making use of Quality of Experience (QoE) as its basis and marshalling its resources optimally around the user. Salient activities of this thesis include: Analysis of CR leads to the definition of its basic functional blocks such as cognition, learning and adaptation of radio behaviour in a multi-disciplinary manner. CR tracts signal processing for radio and sensors, cognitive and behavioural psychology for user intelligence, machine learning and AI for decision systems and optimization etc. Therefore it provides a rich, fertile area to make lateral connections across diverse helds. This thesis proposes a broad definition for CR (called as Unifed Cognitive Radio) inspired by key foundation works described in literature. Besides, it also describes its functionality and its ecosystem. Taking cue from the definition of UCR, this thesis proposes architectural frame-works for various sub-systems. Also their design and implementation is achieved with the aid of a comprehensive tested setup and is tested using realistic scenarios. Builds a set of intelligent decision systems that help to achieve the set goal. This involves various design decisions with a set of diverse algorithms from the world of signal processing, machine learning and articial intelligence. Transitioning disparate small functional entities (mostly built around experiments) into an integrated system that works in real-world environment is the key aspect of this thesis. It is definitely a challenging task. Therefore, starting from deterring the architectural reference frameworks for realizing various sub-systems of UCR to an evaluation based on integrated scenario, this being an important final step constitutes a sign cant amount of work. Analysis and implementation of the integrated system to meet the desired end functionality - QoE centricity of the CR system to satisfy the needs of the end user better is the contribution of this thesis

No description available.

The thesis consists of three parts. In the first part, we introduce the notion of device-cache-aware schedulers. Modern disk subsystems have many megabytes of memory for various purposes such as prefetching and caching. Current disk scheduling algorithms make decisions oblivious of the underlying device cache algorithms. In this thesis, we propose a scheduler architecture that is aware of underlying device cache. We also describe how the underlying device cache parameters can be automatically deduced and incorporated into the scheduling algorithm. In this thesis, we have only considered adaptive caching algorithms as modern high end disk subsystems are by default configured to use such algorithms. We implemented a prototype for Linux anticipatory scheduler, where we observed, compared with the anticipatory scheduler, upto 3 times improvement in query execution times with Benchw benchmark and upto 10 percent improvement with Postmark benchmark. The second part deals with implementing cooperative caching for the Redhat Global File System. The Redhat Global File System (GFS) is a clustered shared disk file system. The coordination between multiple accesses is through a lock manager. On a read, a lock on the inode is acquired in shared mode and the data is read from the disk. For a write, an exclusive lock on the inode is acquired and data is written to the disk; this requires all nodes holding the lock to write their dirty buffers/pages to disk and invalidate all the related buffers/pages. A DLM (Distributed Lock Manager) is a module that implements the functions of a lock manager. GFS’s DLM has some support for range locks, although it is not being used by GFS. While it is clear that a data sourced from a memory copy is likely to have lower latency, GFS currently reads from the shared disk after acquiring a lock (just as in other designs such as IBM’s GPFS) rather than from remote memory that just recently had the correct contents. The difficulties are mainly due to the circular relationships that can result between GFS and the generic DLM architecture while integrating DLM locking framework with cooperative caching. For example, the page/buffer cache should be accessible from DLM and yet DLM’s generality has to be preserved. The symmetric nature of DLM (including the SMP concurrency model) makes it even more difficult to understand and integrate cooperative caching into it (note that GPFS has an asymmetrical design). In this thesis, we describe the design of a cooperative caching scheme in GFS. To make it more effective, we also have introduced changes to the locking protocol and DLM to handle range locks more efficiently. Experiments with micro benchmarks on our prototype implementation reveal that, reading from a remote node over gigabit Ethernet can be upto 8 times faster than reading from a enterprise class SCSI disk for random disk reads. Our contributions are an integrated design for cooperative caching and lock manager for GFS, devising a novel method to do interval searches and determining when sequential reads from a remote memory perform better than sequential reads from a disk. The third part deals with selecting a primary network partition in a clustered shared disk system, when node/network failures occur. Clustered shared disk file systems like GFS, GPFS use methods that can fail in case of multiple network partitions and also in case of a 2 node cluster. In this thesis, we give an algorithm for fault-tolerant proactive leader election in asynchronous shared memory systems, and later its formal verification. Roughly speaking, a leader election algorithm is proactive if it can tolerate failure of nodes even after a leader is elected, and (stable) leader election happens periodically. This is needed in systems where a leader is required after every failure to ensure the availability of the system and there might be no explicit events such as messages in the (shared memory) system. Previous algorithms like DiskPaxos are not proactive. In our model, individual nodes can fail and reincarnate at any point in time. Each node has a counter which is incremented every period, which is same across all the nodes (modulo a maximum drift). Different nodes can be in different epochs at the same time. Our algorithm ensures that per epoch there can be at most one leader. So if the counter values of some set of nodes match, then there can be at most one leader among them. If the nodes satisfy certain timeliness constraints, then the leader for the epoch with highest counter also becomes the leader for the next epoch (stable property). Our algorithm uses shared memory proportional to the number of processes, the best possible. We also show how our protocol can be used in clustered shared disk systems to select a primary network partition. We have used the state machine approach to represent our protocol in Isabelle HOL logic system and have proved the safety property of the protocol.