Teses / dissertações sobre o tema "Protocoles de communications"
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Gerault, David. "Security analysis of contactless communication protocols". Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC103.
Texto completo da fonteMoulierac, Joanna. "Agrégation des communications multicast". Rennes 1, 2006. http://www.theses.fr/2006REN1S151.
Texto completo da fonteMoulierac, Joanna Rubino Gerardo. "Agrégation des communications multicast". [S.l.] : [s.n.], 2006. ftp://ftp.irisa.fr/techreports/theses/2006/moulierac.pdf.
Texto completo da fonteArnal, Fabrice. "Optimisation de la fiabilité pour des communications multipoints par satellite géostationnaire". Phd thesis, Télécom ParisTech, 2004. http://pastel.archives-ouvertes.fr/pastel-00001160.
Texto completo da fonteMota, Gonzalez Sara del Socorro. "Modélisation et vérification de protocoles pour des communications sécurisées de groupes". Toulouse, INPT, 2008. http://ethesis.inp-toulouse.fr/archive/00000628/.
Texto completo da fonteSystems that implement communications in the form of group multicast have increasingly raised security problems. The protection mechanisms applied to that communication rely on symmetrical and asymmetrical key exchanges, and the way these mechanisms are selected does influence the system’s efficiency. Following an in depth analysis of the needs captured by these systems, we defined a model for representing the dynamics of groups, as well as communication among group members. We defined one system architecture which focuses on key creation, exchange and management functions. The system was modeled in UML 2. 0 and checked against security and temporal properties. The approach we followed to investigate temporal requirements may be extended to a broad variety of distributed systems
Mota, Gonzalez Sara Del Socorro. "Modélisation et vérification de protocoles pour des communications sécurisées de groupes". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2008. http://tel.archives-ouvertes.fr/tel-00309824.
Texto completo da fonteMota, Gonzalez Sara del Socorro Villemur Thierry Diaz Michel. "Modélisation et vérification de protocoles pour des communications sécurisées de groupes". Toulouse : INP Toulouse, 2008. http://ethesis.inp-toulouse.fr/archive/00000628.
Texto completo da fonteTourki, Kamel. "Conception et optimisation de protocoles de coopération pour les communications sans fil". Nice, 2008. http://www.theses.fr/2008NICE4006.
Texto completo da fonteCooperative mechanisms are becoming increasingly important in wireless communications and networks to substantially enhance system performance with respect to much less power consumption, higher system capacity and smaller packet loss rate. The idea of cooperation can be traced back to the information theory investigation on relay channel in cellular network. From the system point of view, since Mobile Station (MS) has limitations in single antenna, power, cost and hardware, it is infeasible to use MIMO technology in MS. Mobile users with single antennas can still take advantage of spatial diversity through cooperative space-time encoded transmission. The objective of this thesis is to introduce and discuss various cooperative strategies in wireless communications. In the first part, we present an end-to-end performance analysis of two-hop asynchronous cooperative diversity with regenerative relays over Rayleigh block-flat-fading channels, in which a precoding frame-based scheme with packet-wise encoding is used. This precoding is based on the addition of a cyclic prefix which is implemented as a training sequence. We derive, for equal and unequal sub-channel gains, the bit-error rate and the end-to-end bit-error rate expressions for binary phase-shift keying. We also present the performance of the frame-error rate and the end-to-end frame-error rate. Finally, comparisons between three system configurations, differing by the amount of cooperation, are presented. The second part contains two chapters. In the first chapter, we consider a scheme in which a relay chooses to cooperate only if its source-relay channel is of an acceptable quality and we evaluate the usefulness of relaying when the source acts blindly and ignores the decision of the relays whether they may cooperate or not. In our study, we consider the regenerative relays in which the decisions to cooperate are based on a signal-to-noise ratio (SNR) threshold and consider the impact of the possible erroneously detected and transmitted data at the relays. We derive the end-to-end bit-error rate (BER) for binary phase-shift keying modulation and look at two power allocation strategies between the source and the relays in order to minimize the end-to-end BER at the destination for high SNR. In the second chapter, we consider a scheme in which the relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our study, we consider a regenerative relay in which the decision to cooperate is based on a signal-to-noise ratio (SNR) threshold and consider the effect of the possible erroneously detected and transmitted data at the relay. We derive an expression for the end-to-end bit-error rate (BER) of binary phase-shift keying (BPSK) modulation and look at the optimal strategy to minimize this end-to-end BER at the destination for high SNR. In the third part, we consider a multiple access MAC fading channel with two users communicating with a common destination, where each user mutually acts as a relay for the other one as well as wishes to transmit his own information as opposed to having dedicated relays. We wish to evaluate the usefulness of relaying from the point of view of the system's throughput (sum rate) rather than from the sole point of view of the user benefiting from the cooperation as is typically done. We do this by allowing a trade-off between relaying and fresh data transmission through a resource allocation framework. Specifically, we propose cooperative transmission scheme allowing each user to allocate a certain amount of power for his own transmitted data while the rest is devoted to relaying. The underlying protocol is based on a modification of the so-called non-orthogonal amplify and forward (NAF) protocol. We develop capacity expressions for our scheme and derive the rate-optimum power allocation, in closed form for centralized and distributed frameworks. In the distributed scenario, partially statistical and partially instantaneous channel information is exploited. The centralized power allocation algorithm indicates that even in a mutual cooperation setting like ours, on any given realization of the channel, cooperation is never truly mutual, i. E. One of the users will always allocate zero power to relaying the data of the other one, and thus act selfishly. But in distributed framework, our results indicate that the sum rate is maximized when both mobiles act selfishly
Guitton, Alexandre. "Communications multicast : contributions aux réseaux optiques et au passage à l'échelle". Rennes 1, 2005. https://hal-clermont-univ.archives-ouvertes.fr/tel-01448117.
Texto completo da fonteGuitton, Alexandre Marie Raymond Molnár Miklós. "Communications multicast contributions aux réseaux optiques et au passage à l'échelle /". [S.l.] : [s.n.], 2005. ftp://ftp.irisa.fr/techreports/theses/2005/guitton.pdf.
Texto completo da fonteCaragata, Daniel. "Protocoles de communications sécurisées par des séquences chaotiques : applications aux standards de communications , IP via DVB-S et l'UMTS". Nantes, 2011. http://archive.bu.univ-nantes.fr/pollux/show.action?id=ff503910-6dd7-42e4-9c45-c7e59996eaa2.
Texto completo da fonteIn this thesis we have studied new ways of using chaotic functions to ensure information security. Therefore, we have addressed three themes of research: the security of IP communications over satellite DVB, UMTS security and digital watermarking. Firstly we study the security of unicast and multicast IP communications over satellite DVB. We propose a new security solution for this type of communications that encrypts the IP packet and MAC code and that protects the authenticity and integrity of the ULE header and of the IP packet. This solution uses a multi layer key management system, chaotic functions for the encryption of the data and the generation of the secret keys, a customized PDU for the transport of the keys and an alarm message to restore the synchronization between the ISP and the client. We analyze and propose improvements for the security of the UMTS. The network access is at the heart of UMTS security. The enhancements we propose are: user identification using an improved protocol that ensures the protection of: the permanent identity, the secret key K against cryptographic attacks using a temporary key and the encryption of the messages. The modified protocols for security algorithms negotiation and TMSI updating that make the choices of the serving network visible to the users. Finally, we address the information integrity of JPEG images and we propose a new chaos based fragile watermarking algorithm that is efficient and robust. This algorithm is the result of the cryptanalysis that we have developed against the watermarking algorithm proposed by Wang in 2008. In addition we have also simulated the cryptanalysis using first order Markov chains
Kaisser, Florent. "Communications dans les réseaux fortement dynamiques". Phd thesis, Université Paris Sud - Paris XI, 2010. http://tel.archives-ouvertes.fr/tel-00512021.
Texto completo da fonteBoussemart, Vincent. "Bénéfices de la communication inter-protocoles au niveau applicatif et des ressources pour contrôler les interférences dans les communications satellites". Thesis, Toulouse, ISAE, 2013. http://www.theses.fr/2013ESAE0013/document.
Texto completo da fonteThis Ph.D. investigates resource management optimisations in the return-link of interference-limited multi-beam satellitesystems which can be seen as virtual MIMO systems. It focuses on the interference that users located in different beamsgenerate towards each other, when transmitting data at the same time and on the same frequency. The number offrequencies (colours) present in the satellite system rules the overall bandwidth and therefore the system capacity. Whenthe number of colours becomes low, e.g. considering one colour, the level of interference increases dramatically but thebandwidth available in each beam gets higher. Hence there is a tradeoff between number of colours and level ofinterference. The influence of the satellite channel is first studied by analysing the BER obtained through interferencecancellation techniques. The Ph.D. then moves towards information theory and investigates the impact of the colours onthe achievable sum rates. MUD schemes are then used to derive the per-user rates, and the max-min criterion is applied tothe user rates showing an improvement of the level of fairness between users. The different outcomes are used to optimisethe resource management. However, scheduling for large scale MIMO systems, as in the return-links of satellitecommunications, represents a challenging task, since the search space is prohibitive large. For this reason this Ph.D. alsoinvestigates low complexity heuristic algorithms based on graph theory with the aim of finding sub-optimal schedules.Finally, the number of spot beams and the number of users considered for scheduling are studied so as to propose newalgorithms aiming to satisfy quality of service constraints
Lorchat, Jean. "Optimisation des communications pour les environnements mobiles embarqués". Université Louis Pasteur (Strasbourg) (1971-2008), 2005. https://publication-theses.unistra.fr/public/theses_doctorat/2005/LORCHAT_Jean_2005.pdf.
Texto completo da fonteEmbedded mobile devices are battery-powered devices. This includes traditional laptops as well as PDAs, cell phones and onboard car computers. During this thesis work, we focused on studying communication protocols available to these devices, in order to optimize their energy efficiency. To remain useable, these optimized protocols must be able to support highly constrained traffic like video and voice. We did first develop some models for several wireless communications technologies, based on measurements from the field for various states of the hardware. Then we focused on the IEEE 802. 11 family of protocols, in which the only power saving mechanism is disabling realtime communications by adding a huge amount of latency on inbound traffic. In addition, this mechanism only works with inbound traffic. We thus developped and patent a new mechanism that adds on top of the existing protocol, but with backwards compatibility. This mechanism allowed to increase battery life by 10% , with so little latency that realtime communications are not impacted. This mechanism behaves the same in both ways, which makes it bidirectionnal. Eventually, based on our observations on the limits of IEEE 802. 11 medium access layer, from both energy efficiency and fairness standpoints, we developped a new medium access layer that replaces the old one from the IEEE 802. 11 protocol, but keeps the same underlying physical layer
Ayaida, Marwane. "Contribution aux communications intra-véhicule et inter-véhicules". Thesis, Reims, 2012. http://www.theses.fr/2012REIMS016/document.
Texto completo da fonteModern vehicles are equipped with various devices that aim to automate tasks (shift transmission, cruise control, etc.) or to provide services to the user (driver assistance, obstacle detection, etc.). Communications between vehicles help to expand these services through the collaboration of several vehicles (accident prevention, traffic management, etc.). The proliferation of these devices, their interfaces and protocols makes the data exchange more complex. In addition, inter-vehicle communication is more restrictive because of the vehicles' high mobility.In this work, we propose the design of a communication channel Connect to All (C2A) that ensures the interoperability between embedded devices in a vehicle. In fact, it detects the equipment connection, recognizes it and allows it to exchange data with other devices. The channel design starts by the modelling step using two different techniques (the model checker tool UPPAAL and the Specification and Description Language (SDL). Then, we validate the designed models. We also detail a concrete implementation of the channel on an embedded chip that aims to show the C2A interoperability concept feasibility.We also studied the mobility effects in the inter-vehicular communication through a hybrid approach mixing routing and location-based service. This approach provides a mechanism to reduce vehicle-tracking costs while increasing routing performances. Moreover, we compare two applications of this approach: Hybrid Routing and Grid Location Service (HRGLS) and Hybrid Routing and Hierarchical Location Service (HRHLS) with classical approaches to prove the added value. Then, this approach is improved with a mobility prediction algorithm. The latter allows a better understanding of the vehicle movements by estimating them. Similarly, the hybrid approach with mobility prediction Predictive Hybrid Routing and Hierarchical Location Service (PHRHLS) is compared with the basic approach and HRHLS in order to show the mobility prediction advantages
Saleh, Mohammad. "Secure communications in wireless networks for biomedical EEG sensor networks applications". Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCA024/document.
Texto completo da fonteThe general framework of the thesis concerns sensor networks and the privacy protocols for wireless communications in the implementation of reliable healthcare systems. More precisely, it presents a novel biomedical wireless sensor Network monitoring system, as a predictor and advance sensitive portable electroencephalogram (EEG). The EEG wireless sensor network proposed to monitor spontaneous brain waves, including normal and abnormal waves, for the patients suffering from different types of epilepsy. The biomedical epilepsy wireless sensor Network monitoring system (WSN-EEG) read’s signals from a wireless sensor network on the patient scalp, and filter these signals to run parallel data processing for the brain waves. However, the predicting procedure for the severity of the forthcoming epileptic attack based on, a proposed mathematical model, which analyses the abnormality in the brain waves and alerts by giving signals for the patient. This method can save many patients by predicting the seizure before it occurs and helps them from different injuries and risky behavior arising during epilepsy attack. In addition, the proposed approaches can use the patient data for further medical diagnosis measures. Another approach is proposed as a learning-based approach for prediction using Feed Forward Neural Network (FFNN) for the alert system. The research used the IEEE802.11n as a communication method for the wireless sensor networks and measure the IEEE802.11n security performances as privacy protocol for data transmission of the proposed systems. The measurements indicated the calibration of the prediction algorithms to take account of the delays introduced by the security of the communications in the data transmission and seizure prediction which might significantly reduce prediction time and delay the alert signals
Mouradian, Alexandre. "Proposition et vérification formelle de protocoles de communications temps-réel pour les réseaux de capteurs sans fil". Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00910394.
Texto completo da fonteJerbi, Moez Agoulmine Nazim. "Protocoles pour les communications dans les réseaux de véhicules en environnement urbain routage et geocast basés sur les intersections /". S. l. : S. n, 2008. http://www.biblio.univ-evry.fr/theses/2008/2008EVRY0016.pdf.
Texto completo da fonteJerbi, Moez. "Protocoles pour les communications dans les réseaux de véhicules en environnement urbain : routage et geocast basés sur les intersections". Thesis, Evry-Val d'Essonne, 2008. http://www.theses.fr/2008EVRY0016/document.
Texto completo da fonteInter-Vehicle Communication (IVC) is attracting considerable attention from the research community and the automotive industry, where it is beneficial in providing Intelligent Transportation System (ITS) as well as assistant services for drivers and passengers. In this context, Vehicular Networks are emerging as a novel category of wireless networks, spontaneously formed between moving vehicles equipped with wireless interfaces that could have similar or different radio interface technologies, employing short-range to medium-range communication systems. The distinguished characteristics of vehicular networks such as high mobility, potentially large scale, and network partitioning introduce several challenges, which can greatly impact the future deployment of these networks. In this thesis, we focus on inter-vehicle communication in urban environments. Our main goal is to propose new routing and dissemination algorithms, which efficiently adapts to the vehicular networks characteristics and applications. Temporary disconnection in vehicular network is unavoidable. It is thereby of imminent practical interest to consider the vehicular traffic density. Therefore, at first, we propose a completely distributed and infrastructure–free mechanism for city road density estimation. Then, and based on such traffic information system, we propose a novel intersection-based geographical routing protocol, capable to find robust and optimal routes within urban environments. Finally, in order to help the efficient support of dissemination-based applications, a self-organizing mechanism to emulate a geo-localized virtual infrastructure is proposed, which can be deployed in intersections with an acceptable level of vehicular density. The advocated techniques are evaluated by a combination of network simulation and a microscopic vehicular traffic model
Haj-Hassan, Ali. "Securing communication protocols for the Internet of Things". Electronic Thesis or Diss., Valenciennes, Université Polytechnique Hauts-de-France, 2024. http://www.theses.fr/2024UPHF0002.
Texto completo da fonteThe fusion of IP-enabled networks with low-power wireless technology has given birth tothe Industrial Internet of Things (IIoT). Due the large scale and dynamic nature of IIoT, thesecurity of such network is of paramount importance. One of the most critical attacks arethose conducted during the joining phase of new nodes to an IIoT network. In this thesis, we focus our study on securing the joining phase of such networks.Joining phases in IoT rely on mutual authentication methods based on a pre-shared key (PSK) shared between the network coordinator and the joining node. Standardization often lacks clear PSK sharing guidelines, which in large-scale and dynamic networks like IIoT makes pre-configuring each device with a unique key impractical. To address these concerns, this thesis introduces an autonomous mutual authentication and key establishment protocol for IIoT networks. In this solution, the network coordinator first authenticates the joining node via a certificate, and reciprocally, the joining node authenticates the network coordinator using a novel and lightweight consensus mechanism based on Shamir Secret Sharing. Once this mutual authentication is accomplished, a key is established between the network coordinator and the joining node over a public channel. Our solution was integrated into the 6TiSCH framework, ensuring robust security with high authentication success, even when dealing with malicious nodes. Additionally, it proved efficient in terms of communication, latency, and energy usage across various network scenarios, even on resource-constrained devices.Moreover, during the IoT network joining process, proxy nodes play a pivotal role in forwarding Join Requests and Join Responses between the joining node and the network coordinator. Securing this phase is vital, as malicious proxy nodes can disturb new node joins or redirect them another entity impersonating the coordinator. Therefore, we present a robust system focused on identifying malicious proxy nodes during the joining phase. Centered around the coordinator, this system maintains a log table tracking each node’s participation as a proxy node. Post each joining phase, the coordinator receives an End-to-End encrypted packet from the joining node, detailing any encounters with malicious proxy nodes. This information is utilized to calculate the number of legitimate proxy node involvements for each node. The detection system utilizes these metrics, in conjunction with adjustable parameters, to categorize nodes as either malicious or trustworthy. Additionally, our solution accounts for potential attacks on the detection process, originating from both proxy nodes and joining nodes
Salameh, Nadeen. "Conception d’un système d’alerte embarqué basé sur les communications entre véhicules". Thesis, Rouen, INSA, 2011. http://www.theses.fr/2011ISAM0016/document.
Texto completo da fonteDuring the last recent years, ADAS systems such as collision warning, tracking, night vision and navigation systems have been developed. The development of these systems has witness eda growing importance, as they are expected to help improving both road safety and traffic efficiency. More over, they have an ability to enhance the communication between the road infrastructure and the vehicle or between vehicles for safer and efficient transportation services such as : embedded advance collision, collision avoidance and automatic control. In addition,given the rapidly increasing interest in wireless communications, cooperative ADAS define anew framework of autonomous inter vehicular communication which operates on the assumption that such vehicles consist of a multitude of coordinated advanced sensory technologies.Sensors acquire real-time data about road conditions to help the driver respond effectively by sending appropriate messages between vehicles. In addition, these data help to assess the performance of ADAS in the context of improving driver behavior. It is necessary to set some main metrics such as inter-vehicle distance, driver reaction time and time to collision. The messages are transmitted to drivers using vehicular Ad-hoc networks (VANETs) which are a specific type of Mobile Ad-hoc Networks hold the promise to contribute to safe and more efficient roadways.In this thesis we proposed a new methodology of development to prototype ADAS. This methodology dedicated to cooperative ADAS drove us to implement a new simulated frameworkof prototyping system. This framework combines the data from three models : Geo-localizationGPS, vision and V2V communication towards an application of anti-collision warning system. A major problem in communicating ADAS systems is the quality and robustness of the communication.It depends on a large number of parameters that must be modeled to assess there liability of these systems. We developed a new prototyping system based on the principle ofaugmenting the reality in which we can replay actual data and change settings of communication environment. The GPS data and routing protocols were crucial elements for V2V model simulation into ns-2 simulator. We have performed real tests on the experimental prototyping platform LaRA. Multiple results are presented to show up the constancy of the method and the performance efficiency of real-time multi sensors in an integrated framework for collision avoidance applications. Results of this research have shown that IVCs simulations system provides enhanced data for the verification of features of new ADAS. The results of routing protocols simulation with real-time location data are integrated in the new developed prototype. The implementation of the system warning was used to estimate the number of pre-collisions detected in both real and simulated situations. The difference between these two situations was studied and analyzed for several scenarios corresponding to different road situations
Lebreton, Jean Mickaël. "Systèmes et protocoles de télé-réveil appliqués à l’optimisation énergétique des réseaux de capteurs sans fil". Thesis, La Réunion, 2017. http://www.theses.fr/2017LARE0014/document.
Texto completo da fonteNowadays, a significant growth of connected things is observed, exceeding even the worldpopulation. Given the magnitude of this phenomenon, the energy efficiency of communicatingobjects is a crucial issue. Maximizing their lifetime is necessary to ensure a qualityof service. In this regard, the aim of this thesis is to optimize the energy consumption ofwireless communications in a wireless sensor network.The concept of wake-up radio was created a decade ago, which consists of waking up thecommunicating node by a remote radio signal. By default, the node remains in sleepingmode at a very low power consumption. If needed, the node can be woken up on demandthrough a specific radio signal. Thus, the energy consumption of the radio module is greatlyreduced by idle listening to the channel in sleeping mode. However, this wake-up radioprinciple requires the development of new hardware architectures associated with adaptedand innovative communication protocols. Despite recent proposals, the level of technologymaturity has not yet been reached on this subject.Therefore, a wake-up radio system is proposed in this thesis, including a theoreticalcharacterization of its performances. The wake-up receiver consumes 363 nW in sleepingmode and 49.8 µW in receiving mode. Moreover, two new protocols called DoRa and DC-DoRaare proposed with an evaluation of their performances by simulation. The resultsshow that these wake-up radio protocols greatly reduce the energy consumed by the radiomodule, compared to the MAC protocols currently used in wireless sensor networks. Finally,the experimental implementation of the wake-up radio system and protocols enabled thereal performance measurement of our approach in an environment with overhearing andinterference
Villemur, Thierry. "Conception de services et de protocoles pour la gestion de groupes coopératifs". Phd thesis, Université Paul Sabatier - Toulouse III, 1995. http://tel.archives-ouvertes.fr/tel-00146528.
Texto completo da fonteZidane, Karine. "Techniques d’amélioration des performances des méthodes d’accès aléatoire synchrones pour les communications par satellite". Thesis, Toulouse, ISAE, 2016. http://www.theses.fr/2016ESAE0030/document.
Texto completo da fonteWith the need to provide the Internet access to deprived areas and to cope with constantlyenlarging satellite networks, enhancing satellite communications becomes a crucial challenge.In this context, the use of Random Access (RA) techniques combined with dedicated accesson the satellite return link, can improve the system performance. However conventionalRA techniques like Aloha and Slotted Aloha suffer from a high packet loss rate caused bydestructive packet collisions. For this reason, those techniques are not well-suited for datatransmission in satellite communications. Therefore, researchers have been studying andproposing new RA techniques that can cope with packet collisions and decrease the packet lossratio. In particular, recent RA techniques involving information redundancy and successiveinterference cancellation, have shown some promising performance gains.With such methods that can function in high load regimes and resolve packets with high collisions,channel estimation is not an evident task. As a first contribution in this dissertation, wedescribe an improved channel estimation scheme for packets in collision in new RAmethodsin satellite communications. And we analyse the impact of residual channel estimation errorson the performance of interference cancellation. The results obtained show a performancedegradation compared to the perfect channel knowledge case, but provide a performanceenhancement compared to existing channel estimation algorithms. Another contribution of this thesis is presenting a method called Multi-Replica Decoding using Correlation based Localisation (MARSALA). MARSALA is a new decoding technique for a recent synchronous RAmethod called Contention Resolution Diversity Slotted Aloha (CRDSA). Based on packets replication and successive interference cancellation, CRDSA enables to significantly enhance the performance of legacy RA techniques. However, if CRDSA is unable to resolve additional packets due to high levels of collision, MARSALA is applied. At the receiver side, MARSALA takes advantage of correlation procedures to localise the replicas of a given packet, then combines the replicas in order to obtain a better Signal to Noise plus Interference Ratio. Nevertheless, the performance ofMARSALA is highly dependent on replicas synchronisation in timing and phase, otherwise replicas combination would not be constructive. In this dissertation, we describe an overall framework ofMARSALA including replicas timing and phase estimation and compensation, then channel estimation for theresulting signal. This dissertation also provides an analytical model for the performancedegradation of MARSALA due to imperfect replicas combination and channel estimation.In addition, several enhancement schemes forMARSALA are proposed likeMaximum RatioCombining, packets power unbalance, and various coding schemes. Finally, we show thatby choosing the optimal design configuration for MARSALA, the performance gain can besignificantly enhanced
Salameh, Nadeen. "Conception d'un système d'alerte embarqué basé sur les communications entre véhicules". Phd thesis, INSA de Rouen, 2011. http://tel.archives-ouvertes.fr/tel-00722227.
Texto completo da fonteImadali, Sofiane. "Large scale addressing and routing mechanisms for highly mobile networks of networks". Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112049/document.
Texto completo da fonteAfter successfully connecting machines and people later (world wide web), the new era of In-ternet is about connecting things. Due to increasing demands in terms of addresses, mobility, scalability, security and other new unattended challenges, the evolution of current Internet archi-tecture is subject to major debate worldwide. The Internet Architecture Board (IAB) workshop on Routing and Addressing report described the serious scalability problems faced by large backbone operators in terms of routing and addressing, illustrated by the unsustainable growth of the Default Free Zone (DFZ) routing tables. Some proposals tackled the scalability and IP semantics overload issues with two different approaches: evolutionary approach (backward com-patibility) or a revolutionary approach. Several design objectives (technical or high-level) guided researchers in their proposals. Mobility is definitely one of the main challenges.Inter-Vehicle Communication (IVC) attracts considerable attention from the research com-munity and the industry for its potential in providing Intelligent Transportation Systems (ITS) and passengers services. Vehicular Ad-Hoc Networks (VANETs) are emerging as a class of wire-less network, formed between moving vehicles equipped with wireless interfaces (cellular and WiFi) employing heterogeneous communication systems. A VANET is a form of mobile ad-hoc network that provides IVC among nearby vehicles and may involve the use of a nearby fixed equipment on the roadside. The impact of Internet-based vehicular services (infotainment) are quickly developing. Some of these applications, driver assistance services or traffic reports, have been there for a while. But market-enabling applications may also be an argument in favor of a more convenient journey. Such use cases are viewed as a motivation to further adoption of the ITS standards developed within IEEE, ETSI, and ISO.This thesis focuses on applying Future Internet paradigm to vehicle-to-Internet communica-tions in an attempt to define the solution space of Future Vehicular Internet. We first introduce two possible vehicle-to-Internet use cases and great enablers for IP based services : eHealth and Fully-electric Vehicles. We show how to integrate those use cases into IPv6 enabled networks. We further focus on the mobility architectures and determine the fundamental components of a mobility architecture. We then classify those approaches into centralized and distributed to show the current trends in terms of network mobility extension, an essential component to vehicular networking. We eventually analyze the performance of these proposals. In order to define an identifier namespace for vehicular communications, we introduce the Vehicle Identification Numbers are possible candidates. We then propose a conversion algorithm that preserves the VIN characteristics while mapping it onto usable IPv6 networking objects (ad-dresses, prefixes, and Mobile Node Identifiers). We make use of this result to extend LISP-MN protocol with the support of our VIN6 addressing architecture. We also apply those results to group IP-based communications, when the cluster head is in charge of a group of followers
Rivoirard, Lucas. "Modèle d'auto-organisation pour les protocoles de routage dans les réseaux ad hoc de véhicules : application à la perception élargie et à la localisation coopératives". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1I041/document.
Texto completo da fonteAutomated driving can reduce accidents and improve the traffic flow by using communications between vehicles and dedicated infrastructures. Maintaining services when an infrastructure failed requires a routing protocol adapted to vehicle-to-vehicle (V2V) communications. This dissertation assumes the absence of dedicated infrastructure and global location service, each vehicle knowing its only own position. A V2V communication organization model, CBL, is proposed to create and maintain a structure that supports close exchanges between neighbouring vehicles and remote exchanges through the traffic. CBL creates a hierarchy where disjoint groups of neighbouring vehicles (leaves) are connected via a leader vehicle (branch) to a backbone (chain) formed along the road by the interconnection of the branches. CBL requires only the knowledge of the one-hop neighborhood and can be integrated into any routing protocol. The evaluations on road scenarios using IEEE-based traffic recommended on road environments in terms of size and message frequency show that CBL makes a better use of the spatial constraints due to the road. A structure is obtained that suits better in the optimisation of the broadcast traffic than the technique of multipoint relays in OLSR, but also compared to DSR, AODV and GRP protocols. Evaluations of cooperative application traffic such as ego-localization and extended perception show that CBL offers a communication service with low latency, low packet loss, according to a wanted trade-off between message frequency and performance
Chebbi, Emna. "De la modélisation formelle à la simulation à évènements discrets : application à la conception et à l'évaluation de protocoles sûrs et sécurisés pour les communications dans les transports". Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0538.
Texto completo da fonteThe design of communication protocols is generally based on functional models developed from the system needs. In Intelligent Transport Systems (ITS), the studied functionalities include self-organization, routing, reliability, quality of service and security. Simulation evaluations of ITS protocols mainly focus on performance in specific scenarios. However, the evolution of transportation towards autonomous vehicles requires robust protocols offering guarantees on some of their properties. Formal approaches make it possible to provide automatic proof of certain properties, but for others it is necessary to use interactive proof involving the knowledge of an Expert. The work carried out in this thesis aims to develop, in the DEVS formalism (Discrete Event System Specification), models of an ITS whose simulation would make it possible to observe the properties, possibly verified by a formal approach, in a broader scenario and to generate data on the models that could feed an interactive proof loop instead of an Expert. Targeting the CBL-OLSR (Chain-Branch-Leaf in Optimized Link State Routing) protocol, this thesis shows how a DEVS model and an equivalent formal Event-B model can be built from the same functional specification of an ad hoc network where nodes use this protocol. Safety and security properties are introduced into the formal Event-B model to be verified, and a methodology is proposed to transfer them to an equivalent DEVS model in the form of constraints, choices or observables according to preproposed criteria. Finally, this thesis also opens up the prospects for automating this design process, integrating real data on both road traffic and vehicle application flows into DEVS simulation, and interacting with specialized simulators for the various components (e. g. MATLAB for propagation models, OPNET or NS3 for communications, SUMO for mobility models); the aim being to evaluate the protocol in a very realistic system context
Mainaud, Bastien. "Réseaux de capteurs pour l'assistance aux personnes : conception et développement de mécanismes de fiabilisation". Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2010. http://www.theses.fr/2010TELE0015.
Texto completo da fonteWireless Sensors Networks is a very active research area with a very large scope of possible application. In particular, assistance to person is one of the promising applications. The constraints in this kind of networks are strong and needs of specifics mechanisms. Energy consumption and security are particularly important and are subject of several works. Assistance to person set some robustness constraints and communications reliability. The goal of these works is to define several solutions to answer to these problematic. This work has been split in three different parts. First, a communication platform based on Personal Network techniques was defined. This platform was design, develop and install in a Paris metro station. We made an analytical model of our platform to perform an analysis of its performances. This analysis and the results from the platform installation itself allow us to clearly define the architecture weaknesses and the technologies drawbacks. Second, we developed several solutions to bring reliability to the platform. First, we designed a scheduling algorithm allowing to reduce the bandwidth utilization. This algorithm uses a semantic data analysis to help the data scheduling. Then, we define a solution bringing security to the communications between a sensor node and a remote monitoring terminal. This solution allows to establish a secure end-to-end tunnel between two entities in an heterogeneous network. At last, we were interested to the communications between the platform and the mobile terminal. We focus our work on the reliability aspect of the communications. So, in the last part of this thesis, we suggest a routing protocol using a metric based on the RSSI. Then, we define a cooperative protocol bringing more reliability to the communications
Lundy, G. M. "Systems of communicating machines : a model for communication protocols". Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8210.
Texto completo da fonteDalle, Olivier. "Techniques et outils pour les communications et la répartition dynamique de charge dans les réseaux de stations de travail". Phd thesis, Université de Nice Sophia-Antipolis, 1999. http://tel.archives-ouvertes.fr/tel-00712754.
Texto completo da fonteMainaud, Bastien. "Réseaux de capteurs pour l'assistance aux personnes : conception et développement de mécanismes de fiabilisation". Thesis, Evry, Institut national des télécommunications, 2010. http://www.theses.fr/2010TELE0015/document.
Texto completo da fonteWireless Sensors Networks is a very active research area with a very large scope of possible application. In particular, assistance to person is one of the promising applications. The constraints in this kind of networks are strong and needs of specifics mechanisms. Energy consumption and security are particularly important and are subject of several works. Assistance to person set some robustness constraints and communications reliability. The goal of these works is to define several solutions to answer to these problematic. This work has been split in three different parts. First, a communication platform based on Personal Network techniques was defined. This platform was design, develop and install in a Paris metro station. We made an analytical model of our platform to perform an analysis of its performances. This analysis and the results from the platform installation itself allow us to clearly define the architecture weaknesses and the technologies drawbacks. Second, we developed several solutions to bring reliability to the platform. First, we designed a scheduling algorithm allowing to reduce the bandwidth utilization. This algorithm uses a semantic data analysis to help the data scheduling. Then, we define a solution bringing security to the communications between a sensor node and a remote monitoring terminal. This solution allows to establish a secure end-to-end tunnel between two entities in an heterogeneous network. At last, we were interested to the communications between the platform and the mobile terminal. We focus our work on the reliability aspect of the communications. So, in the last part of this thesis, we suggest a routing protocol using a metric based on the RSSI. Then, we define a cooperative protocol bringing more reliability to the communications
Alkhechi, Ahmad Bassel. "Contribution a la modelisation qualitative et quantitative des protocoles de communication : application au protocole xtp". Paris 6, 1994. http://www.theses.fr/1994PA066007.
Texto completo da fonteMejri, Asma. "Systèmes de communications multi-utilisateurs : de la gestion d'interférence au codage réseau". Thesis, Paris, ENST, 2013. http://www.theses.fr/2013ENST0086/document.
Texto completo da fonteThis work is dedicated to the analysis, design and performance evaluation of physical layer network coding strategies in multiuser communication systems. The first part is devoted to study the compute-and-forward protocol in the basic multiple access channel. For this strategy, we propose an optimal solution to design efficient network codes based on solving a lattice shortest vector problem. Moreover, we derive novel bounds on the ergodic rate and the outage probability for the CF operating in fast and slow fading channels respectively. Besides, we develop novel decoding algorithms proved numerically to outperform the traditional decoding scheme for the CF. The second part is dedicated to the design and end-to-end performance evaluation of network codes for the CF and the analog network coding in the two-way relay channel and the multi-source multi-relay channel. For each network model we study the decoding at the relay nodes and the end destination, propose search algorithms for optimal network codes for the CF and evaluate, theoretically and numerically, the end-to-end error rate and achievable transmission rate. In the last part, we study new decoders for the distributed MIMO channel termed integer forcing (if). Inspired by the CF, if receivers take advantage of the interference provided by the wireless medium to decode integer linear combinations of the original codewords. We develop in our work efficient algorithms to select optimal if receivers parameters allowing to outperform existing suboptimal linear receivers
Asfour, Taghrid. "Protocoles de communication multicast fiables". Paris : École nationale supérieure des télécommunications, 2001. http://catalogue.bnf.fr/ark:/12148/cb388211552.
Texto completo da fonteLink, Jeffrey P. "Design of a serial communication protocol and bus interface chip for tactile communications". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA362194.
Texto completo da fonteThesis advisor(s): Douglas J. Fouts. "March 1999". Includes bibliographical references (p. 285). Also available online.
Wei, K.-K. "Modelling of communication protocols". Thesis, University of York, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373307.
Texto completo da fonteNuggehalli, Pavan S. "Energy conscious communication protocols /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2003. http://wwwlib.umi.com/cr/ucsd/fullcit?p3091328.
Texto completo da fonteBossert, Georges. "Exploiting Semantic for the Automatic Reverse Engineering of Communication Protocols". Thesis, Supélec, 2014. http://www.theses.fr/2014SUPL0027/document.
Texto completo da fonteThis thesis exposes a practical approach for the automatic reverse engineering of undocumented communication protocols. Current work in the field of automated protocol reverse engineering either infer incomplete protocol specifications or require too many stimulation of the targeted implementation with the risk of being defeated by counter-inference techniques. We propose to tackle these issues by leveraging the semantic of the protocol to improve the quality, the speed and the stealthiness of the inference process. This work covers the two main aspects of the protocol reverse engineering, the inference of its syntactical definition and of its grammatical definition. We propose an open-source tool, called Netzob, that implements our work to help security experts in their work against latest cyber-threats. We claim Netzob is the most advanced published tool that tackles issues related to the reverse engineering and the simulation of undocumented protocols
Hadded, Mohamed. "Design and optimization of access control protocols in Vehicular Ad Hoc Networks (VANETs)". Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2016. http://www.theses.fr/2016TELE0023.
Texto completo da fonteRoad crashes and their damages represent a serious issue and are one of the main causes of people death. In this context, Vehicular Ad hoc NETworks (VANETs) are deployed to reduce the risk of road accident as well as to improve passengers’ comfort by allowing vehicles to exchange different kinds of data which ranges widely from road safety and traffic management to infotainment. Nowadays, safety applications are receiving a great deal of attention from researchers as well as from automobile manufacturers. In this thesis, we particularly focus on safety-critical applications, designed to provide drivers assistance in dangerous situations and to avoid accidents in highway environments. Such applications must guarantee to the vehicles access to the medium and have strict requirements regarding end-to-end delay and packet loss ratio. Therefore, our main goal is to propose new medium access control and routing protocols, which can efficiently adapt to frequent changing VANET network topologies. After a comprehensive overview of free-contention MAC protocols, we propose several solutions, based on Time Division Multiple Access Technique (TDMA). We have designed DTMAC, a fully distributed TDMA-based MAC protocol, which does not rely on an expensive infrastructure. DTMAC uses vehicles’ locations and a slot reuse concept to ensure that vehicles in adjacent areas have collision-free schedule. Using simulations, we prove that DTMAC provides a lower rate of access and merging collisions than VeMAC, a well-known TDMA based MAC protocol in VANET. Then, in order to ensure that event-driven safety messages can be sent over a long distance, we propose TRPM, a TDMA aware Routing Protocol for Multi-hop communication. Our routing scheme is based on a cross layer approach between the MAC and the routing layers, in which the intermediate vehicles are selected using TDMA scheduling information. Simulation results show that TRPM provides better performances in terms of average end-to-end delay, average number of hops and average delivery ratio. In the second part, we focus on coordinator-based TDMA scheduling mechanisms. First, we propose the Centralized TDMA based MAC protocol (CTMAC) which uses Road Side Units (RSUs) as a central coordinator to create and maintain the TDMA schedules. CTMAC implements an Access Collision Avoidance mechanism that can prevent the access collision problem occurring more than twice between the same vehicles that are trying to access the channel at the same time. Using simulation we show an improvement in terms of access and merging collisions as well as the overhead required to create and maintain the TDMA schedules compared to distributed scheduling mechanisms. However, in the CTMAC protocol, fast moving vehicles will need to compete for new slots after a short period of time when they leave their current RSU area, which makes a centralized scheduling approach very expensive. In order to further improve the performance of coordinator-based TDMA scheduling mechanisms, we focus on cluster-based TDMA MAC protocols in which some vehicles in the network are elected to coordinate the channel access, allowing the vehicles to remain connected with their channel coordinator for a longer period of time. To this end, first we propose an adaptive weighted clustering protocol, named AWCP, which is road map dependent and uses road IDs and vehicle directions to make the clusters’ structure as stable as possible. Then, we formulate the AWCP parameter tuning as a multi-objective problem and we propose an optimization tool to find the optimal parameters of AWCP to ensure its QoS. Next, we propose ASAS, an adaptive slot assignment strategy for a cluster-based TDMA MAC protocol. This strategy is based on a cross layer approach involving TDMA and AWCP. The objective is to overcome the inter-cluster interference issue in overlapping areas by taking into account vehicles’ locations and directions when the cluster head assign slots
Costa, Daniel Gouveia. "Uma arquitetura baseada em SCTP e SIP para suporte a aplica??es VoIP m?veis e a especifica??o formal do seu m?dulo de controle". Universidade Federal do Rio Grande do Norte, 2006. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15461.
Texto completo da fonteNew versions of SCTP protocol allow the implementation of handover procedures in the transport layer, as well as the supply of a partially reliable communication service. A communication architecture is proposed herein, integrating SCTP with the session initiation protocol, SIP, besides additional protocols. This architecture is intended to handle voice applications over IP networks with mobility requirements. User localization procedures are specified in the application layer as well, using SIP, as an alternative mean to the mechanisms used by traditional protocols, that support mobility in the network layer. The SDL formal specification language is used to specify the operation of a control module, which coordinates the operation of the system component protocols. This formal specification is intended to prevent ambiguities and inconsistencies in the definition of this module, assisting in the correct implementation of the elements of this architecture
Novas vers?es do protocolo SCTP permitem sua utiliza??o para implementa??o de mecanismos de handover em n?vel de transporte, bem como o fornecimento de um servi?o de transmiss?o de dados parcialmente confi?vel. Integrando o SCTP com o protocolo de inicia??o de sess?es, SIP, al?m de utilizar adicionalmente servi?os de outros protocolos auxiliares, uma arquitetura de comunica??o p?de ser proposta, a fim de atender ?s aplica??es de voz sobre IP com requisitos de mobilidade. S?o especificados ainda os procedimentos de localiza??o de usu?rio em n?vel de aplica??o, utilizando o protocolo SIP, como alternativa aos mecanismos empregados por protocolos tradicionais que suportam mobilidade na camada de rede. A linguagem de especifica??o formal SDL ? utilizada para especificar o funcionamento de um M?dulo de Controle, relacionado ? opera??o coordenada dos protocolos que comp?e a arquitetura. Pretende-se assim evitar ambig?idades e inconsist?ncias na defini??o desse m?dulo, o que pode auxiliar em implementa??es corretas de elementos dessa arquitetura
Kahlouche, Hakim. "Méthodologie de développement de protocoles de communication et des applications réparties. Vers une approche de synthèse". Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1997. http://tel.archives-ouvertes.fr/tel-00822102.
Texto completo da fonteConti, Giovanni. "Méthodologie d'implantation des protocoles de communication /". [S.l.] : [s.n.], 1990. http://library.epfl.ch/theses/?nr=842.
Texto completo da fonteAndrey, Laurent. "Protocoles de communication et grammaires attribuées". Nancy 1, 1993. http://www.theses.fr/1993NAN10083.
Texto completo da fonteLaclau, Marie. "Jeux répétés en réseaux et communication". Phd thesis, HEC, 2012. http://pastel.archives-ouvertes.fr/pastel-00741919.
Texto completo da fonteLouail, Lemia. "Approches cross-layer pour l'optimisation de la latence des communications dans les réseaux de capteurs sans fil". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2063/document.
Texto completo da fonteTraditionally, in Wireless Sensor Networks, protocols are designed independently in the layered protocol stack, and metrics involved in several layers can be affected. Communication latency is one metric example, impacted by both the routing protocol in the network layer and the MAC protocol in the data link layer. Cross-layer protocols are known to be more efficient when exploiting the dependencies between these layers.In this context, and aiming to minimize the communication latency, we propose different cross-layer approaches concerning routing trees and TDMA schedules. First, we propose a routing approach using information of the TDMA schedule. Then, we propose different TDMA scheduling approaches which use information of the routing tree. Finally, we propose an approach that combines MAC and routing to produce a routing tree and a TDMA schedule simultaneously. Extensive simulations have shown better results of our contributions compared to the state of the art in terms of latency. Other metrics such as the energy consumption, the duty cycle of the nodes and the number of hops in the routing paths were also considered during the evaluation of our contributions
Horan, Stephen, e Giriprassad Deivasigamani. "USING LABVIEW TO DESIGN A FAULT-TOLERANT LINK ESTABLISHMENT PROTOCOL". International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605784.
Texto completo da fonteThe design of a protocol for a satellite cluster link establishment and management that accounts for link corruption, node failures, and node re-establishment is presented in this paper. This protocol will need to manage the traffic flow between nodes in the satellite cluster, adjust routing tables due to node motion, allow for sub-networks in the cluster, and similar activities. This protocol development is in its initial stages and we will describe how we use the LabVIEW Sate Diagram tool kit to generate the code to design a state machine representing the protocol for the establishment of inter-satellite communications links.
Curty, Alonso Marcos. "Cryptographic protocols in optical communication". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979048621.
Texto completo da fonteHaqqani, Mujeeb. "Fast prototyping of communication protocols". Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5718.
Texto completo da fonteLu, Ching-sung. "Automated validation of communication protocols /". The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu148726702499786.
Texto completo da fonte