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Kulkarni, Santosh B. Umphress David A. Agrawal Prathima. "Synergy MAC a cooperative MAC protocol /." Auburn, Ala, 2009. http://hdl.handle.net/10415/1609.
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Grepl, Miroslav. "MAC řízení přístupu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217509.
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This master's thesis describes the problems of SELinux, and the methods of creation of a proper security policy with a focus on the SELinux reference policy and its mechanisms. It designs the methodics of formulation of specific security rules, supplemented with the practical example of its application. Furthermore, it describes the available security rules commonly used for http, ftp and ssh services securing, their modification and practical utilization. According to the proposed methodology, these services are protected with their own security rules and both security methods are mutually compared and evaluated.
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Mac, Lochlainn Antain. "Aindrias Mac Cruitin : Danta." Thesis, University of Ulster, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241992.
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Золотова, Світлана Григорівна, Светлана Григорьевна Золотова, Svitlana Hryhorivna Zolotova, and Y. Prokhnenko. "Comparing Mac and PC." Thesis, Видавництво СумДУ, 2008. http://essuir.sumdu.edu.ua/handle/123456789/16054.
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McElroy, Mathew S. "Fannie Mae and Freddie Mac lending patterns along the Texas-Mexico border." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Idland, Christer. "Detecting MAC Spoofing Attacks in 802.11 Networks through Fingerprinting on the MAC Layer." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for telematikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14093.
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In order to provide hassle-free connection options many wireless local area network (WLAN) providers choose to have their networks completely open. In other words there is no password required in order to connect. Such open configurations do not provide any security features on the wireless medium, but are often implemented with other solutions as captive portals. A captive portal forces a Hypertext Transfer Protocol (HTTP) client to see a certain webpage, usually for authentication purposes. All other packets are blocked. Once authenticated, the client's medium access control (MAC) address is whitelisted and he will have access to the Internet.The MAC spoofing attack is easy to perform in open networks, see Appendix A. This attack can have severe consequences as the attacker masquerades as a legitimate client, potentially getting the victim caught for crime done by the attacker. The preferred way to handle these attacks has been through detection, as it can be done on the server side without complicating anything for the user. Effective and reliable detection techniques for plain and QoS enabled 802.11 networks exists [1,5]. However, no good solution exists to detect attacks when the legitimate client is no longer connected. The two main scenarios are the session hijacking attack, where the attacker forces the victim offline, and the wait-for-availability attack where the attacker waits until the legitimate client leaves the network.An algorithm based on MAC layer fingerprinting was developed to detect the class of attacks where attacker and victim are not connected simultaneously. A fingerprint is based on the behavior of a station (STA), and each STA's behavior varies due to implementation differences of the 802.11 protocol. Experiments in a real network was performed with 11 different STAs in order to determine the fingerprints. The results show that on average 2.82 of the 8 fingerprinting properties were different when comparing two fingerprints.The fingerprinting algorithm developed is capable of passively creating a fingerprint of wireless STAs without specialized equipment in realistic network conditions. Fingerprints from different STAs are unique with high probability, even when there are little data available. In addition, the technique used is accurate, fast, and requires no pre-computed databases. The algorithm used in combination with the IDS developed by Idland [1] is now able to detect all of the five different MAC spoofing attacks described in Section 2.6.2.
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Balakrishnan, Manikanden, Subah Ramakrishnan, and Hong Huang. "ENERGY-AWARE SENSOR MAC PROTOCOLS." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605793.
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International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaSensor network applications typically require continuous monitoring of physical phenomena for extended periods of time under severe energy resource constraints. Accordingly, design considerations for sensor Media Access Control (MAC) protocols depart significantly from those of traditional wireless MAC protocols that largely ignore the energy factor. In this paper, we reexamine the design space of wireless sensor MAC protocols and modify IEEE 802.11 Distributed Coordination Function (DCF) to incorporate energy-adaptive contention mechanisms for prolonging sensor lifetime. Performance of the proposed schemes is evaluated with DCF as a baseline and results indicate the benefits of energy-aware mechanisms for sensor MAC protocols.
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Vermillac, Michel. "Mac Luhan et la modernité." Nice, 1993. http://www.theses.fr/1993NICE2021.
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L'histoire des idées fonctionne comme un crible : certains auteurs sont recueillis avec ferveur, d'autres non. A ce sujet, Bateson parle d'une véritable écologie de l'esprit. Herbert Marshall Mac Luhan (1911-1980) a connu un sort paradoxal : annonçant la modernité, ce qu'il nomme la galaxie Marcani. Il a été rejeté par les philosophes français de 1968. Or, ses idées seront reprises par les penseurs de la postmodernité, en guise de reconnaissance posthume. Nous avons voulu savoir les raisons de ce revirement. Pourquoi un homme aussi célèbre a-t-il été ignore par la "pensée 68" ? Pourquoi a-t-il été représenté comme un prophète, alors que l'évolution technologique a corroboré ses intuitions ? Malgré ses attaques contre le livre, plus exactement contre la rationalité littéraire, Mac Luhan est un humaniste prônant, dans une réalité quotidienne néobaroque, une forme de fidéisme : s’il n'est plus possible de penser le monde, car l'illusion règne, la force du lien entre les hommes doit donner sens à la vieHistory of ideas works like a riddle : some authors are selected, some not. Thinking of this, Bateson talks about a real ecology of mind. Herbert Marshall Mac Luhan (1911-1980) was a living paradox : introducing modernity with his concept of marconi galaxy, he was ignored by french thinkers of the late sixties. Or, the same ideas will be taken again, without refering to him, by post modernity philosophers. What are the reasons of such a contempt ? Why an essayist as famous as Mac Luhan was not accepted by the french intelligentzia of 1968 ? Was he a prophet, when he was annoucing the future of technology ? Not with standing his attacks against rationality, mac luhan was an humanist, maybe a fideist : if it's difficult to build a clear vision of the world, because of the stength of illusion, relationship between men must give a meaning to modern life
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Silva, Pedro Miguel Oliveira da. "MAC protocol for location systems." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2082.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesNa ultima década as redes de comunicações sem fios sofreram uma evolução sem precedentes, e as suas características particulares potenciaram a sua aplicação em vários contextos. No caso caso específico da localização em ambientes interiores, pretende-se que através de dados recolhidos por um conjunto de sensores sem fios, seja possível detectar com relativa precisão um objecto móvel devidamente identificado. Este tipo de sistemas permitem por exemplo, monitorizar um paciente de risco num hospital, dando informação precisa do seu paradeiro no momento da ocorrência de algum incidente. Outra possível aplicação será, por exemplo, dentro de uma empresa ou instituição, recolher informação precisa sobre o paradeiro de cada trabalhador, visitante ou produto. Isto permite melhorar a logística a gestão dos recursos. As soluções comuns de localização não endereçam devidamente a problemática de acesso ao meio para a realização de transmissões. Isto tem impacto na eficiência de utilização do canal de comunicações e resulta num número inferior de localizações por unidade de tempo. Estes sistemas revelam assim a necessidade de um protocolo de acesso ao meio específico que permita reduzir o tempo necessário à localização de cada dispositivo móvel permitindo a integração de um número mais elevado dispositivos móveis ou fixos numa rede de localização. Esta tese explora a utilização de Zigbee para implementar um protocolo master/multi-slave (FTT-L) aplicado a um sistema de localização. Este protocolo bem como a sua implementação é descrita neste documento. São também conduzidos vários testes para determinar alguns parâmetros chave. Os resultados são utilizados para derivar o tempo mínimo de localização que é validado experimentalmente. ABSTRACT: In the last decade the proliferation of wireless communication networks has reached unprecedented values, and their features empowered the application of wireless networks to the most varied contexts. In the specific case of indoor location, the target is to detect with relative precision an identified mobile object with the data collected from a wireless sensor network. This system allows us to monitor a risk patient in an hospital, giving the precise information about its location at the moment of a possible accident. Other possible application is, for example, to gather inside a company or institution the precise location of every worker, visitor or product. This can improve the logistics and the management of the personnel. The common location solutions do not address the problematic of medium access for transmitting messages. This has impact on the transmission channel occupation and indirectly lowers the system efficiency, which results on a smaller number of locations per unit of time. These systems reveal the necessity of a specific protocol for accessing the medium to reduce the necessary time to locate each mobile device, allowing the integration of a larger number of mobile devices or fixed devices in a location network. This thesis explores the use of ZigBee to implement a master/multi-slave protocol (FTT-L) supporting a localization system. This protocol as well as its implementation are described throughout the thesis and an assessment of several key parameters is conducted. Results are used to derive the delay of a localization round, which was validated experimentally.
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García, Long Sergio Alonso. "Un Big MAC por favor : la cláusula MAC en las operaciones de fusiones y adquisiciones." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2015. http://tesis.pucp.edu.pe/repositorio/handle/123456789/6925.
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Diab, Rana. "HMC-MAC : un protocole MAC hybride et multi-canal pour les réseaux de capteurs sans fil." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22580/document.
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L'utilisation des canaux multiples améliore significativement les performances globales des réseaux de capteurs sans fil (RCSF) en permettant des transmissions parallèles sur plusieurs canaux. Cependant, la mise en place d’un protocole MAC multi-canal dans un réseau multisauts nécessite une méthode efficace d’allocation des canaux pour permettre une coordination entre les nœuds afin de partager les canaux disponibles. Dans cette thèse, nous nous intéressons à la conception d’un protocole MAC multi-canal qui répond aux exigences des applications de collecte de données à haut débit dans un réseau multi-saut. Pour ce faire, nous abordons d’abord les principales façons d’utiliser plusieurs canaux pour réaliser le partage du médium. Ensuite, nous proposons un protocole MAC multi-canal, répondant aux exigences des RCSF à haut débit, qui combine les trois techniques TDMA, CSMA et FDMA. En effet, nous utilisons une nouvelle méthode d’allocation des canaux qui permet aux nœuds de choisir le canal de réception le plus convenable dans leurs voisinages jusqu’à 3-sauts d’une façon distribuée afin de minimiser les effets des interférences et des collisions. Enfin, nous évaluons par simulation les performances de notre protocole et nous le comparons à d’autres protocoles proposés dans la littérature. Les résultats obtenus montrent l’efficacité de notre proposition dans les différents scénarios étudiésThe use of multi-channel significantly improves the overall network performance of wireless sensor networks (WSNs) by allowing parallel transmissions over multiple channels. However, the design of a multi-channel MAC protocol in a multi-hop network requires an efficient channel allocation method that allows the coordination between the nodes in order to share available channels. In this thesis, we focus on the conception of a multi-channel MAC protocol that meets the requirements of high data collection applications in a multi-hop network. In order to achieve this goal, we first present the main techniques to use multiple channels to realize medium access sharing. Then, we propose a multi-channel MAC protocol that meets the requirements of high data rate WSNs, which combines three techniques TDMA, FDMA and CSMA. Indeed, we use a new channel assignment method that enables nodes to choose the most convenient channel in their 3-hop neighborhood in a distributed manner in order to minimize the effects of interferences and collisions. Finally, we evaluate by simulation the performance of our protocol and we compare it to other protocols proposed in the literature. The results show the efficiency of our proposition in the different studied scenarios
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Khoulani, Amer, and Ramaz Samhan. "Performance Analysis of WLAN MAC Algorithms." Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3200.
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Lately, researchers were trying to put a lot of efforts to enhance the performance of Wireless LANs. IEEE 802.11 algorithm, DCF, was an interesting subject for studies. Most studies were concentrating on avoiding collisions, packets loss, decreasing transmission delay and enhancing the overall performance of the network. Double Increment Double Decrement (DIDD) was introduced as a solution that enhance the performance by applying some changes in the algorithm. The main changes were applied on the Contention Window (CW). IEEE 802.11e introduced a new algorithm (EDCA) that introduces a QoS to the performance and though improves the overall performance of the WLAN This thesis aim is to study the performance of three different MAC algorithms by applying two different scenarios on legacy DCF, DIDD and EDCA. Analyzing different output results and checking the QoS of each algorithm. Simulations are implemented in Network Simulator 2 (ns-2) to simulate the network and communication procedures. By deducing and analyzing the output results of the main simulation, DIDD shows improvements that are slightly better than the legacy DCF, while EDCA shows better results from both DCF and DIDD. Though, EDCA shows a noticeable enhancement in the performance of the WLAN.
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Ali, Mohammad Tariq. "MAC alternatives for LMCS/LMDS networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq36883.pdf.
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Jang, Beakcheol. "Wireless MAC Protocol Design and Analysis." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-05262009-175059/.
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Wireless networks are becoming very common due to their advantages such as rapid deployment and support for mobility. In this dissertation, we design and analyze the Medium Access Control (MAC) protocol for two popular wireless networks: Wireless Sensor Networks (WSNs) and Wireless Local Area Networks (WLANs). For WSNs, we design and analyze an energy efficient MAC protocols. Energy efficiency is a key design factor of a MAC protocol for WSNs. Existing preamble-sampling based MAC protocols have large overheads due to their preambles and are inefficient at large wakeup intervals. Synchronous scheduling MAC protocols minimize the preamble by combining preamble sampling and scheduling techniques; however, they do not prevent energy loss due to overhearing. In this dissertation, we present an energy efficient MAC protocol for WSNs, called AS-MAC, that avoids overhearing and reduces contention and delay by asynchronously scheduling the wakeup time of neighboring nodes. We also provide a multi-hop energy consumption model for AS-MAC. To validate our design and analysis, we implement the proposed scheme on the MICAz and TELOSB platforms. Experimental results show that AS-MAC considerably reduces energy consumption, packet loss and delay when compared with other energy efficient MAC protocols. For WLANs, we present a saturation throughput model for IEEE 802.11, the standard of WLAN, for a simple infrastructure scenario with hidden stations. Despite the importance of the hidden terminal problem, there have been a relatively small number of studies that consider the effect of hidden terminals on IEEE 802.11 throughput. Moreover, existing models are not accurate for scenarios with the short-term unfairness. In this dissertation, we present a new analytical saturation throughput model for IEEE 802.11 for a simple but typical infrastructure scenario with small number of hidden stations. Simulation results are used to validate the model and show that our model is extremely accurate. Lastly, we provide a saturation throughput model for IEEE 802.11 for the general infrastructure scenario with hidden stations. Simulation results show that this generalized model is reasonably accurate.
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Gu, Yuzhou. "Zero-error communication over adder MAC." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120387.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 53-54).
Adder MAC is a simple noiseless multiple-access channel (MAC), where if users send messages X₁, . . . ,X[subscript h] [epsilon] {0, 1}[superscript n], then the receiver receives Y = X₁ + · · · + X[subscript h] with addition over Z. Communication over the noiseless adder MAC has been studied for more than fifty years. There are two models of particular interest: uniquely decodable code tuples, and B[subscript h]-codes. In spite of the similarities between these two models, lower bounds and upper bounds of the optimal sum rate of uniquely decodable code tuple asymptotically match as number of users goes to infinity, while there is a gap of factor two between lower bounds and upper bounds of the optimal rate of B[subscript h]-codes. The best currently known B[subscript h]-codes for h >/- 3 are constructed using random coding. In this thesis, we study variants of the random coding method and related problems, in hope of achieving B[subscript h]-codes with better rate. Our contribution include the following. 1. We determine the rate achieved by changing the underlying distribution used in random coding. 2. We determine the rate of a list-decoding version of B[subscript h]-codes achieved by the random coding method. 3. We study several related problems about Rényi entropy.
by Yuzhou Gu.
M. Eng.
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Tomas, Ilda. "Mac orlan au carrefour des arts." Paris 3, 1988. http://www.theses.fr/1989PA030109.
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Une lecture attentive de p. Mac orlan fondee sur la mise en relief de themes obsessionnels montre un certain nombre de constantes qui ne peuvent apparaitre lors d'une approche hative. Perception visuelle aigue, analyse et prescience etonnantes, multiples directions prises par une creation dont la contexture est faite de souvenirs et d'imagination: telles sont les grandes voies tracees par cet ecrivain aussi a l'aise dans la chanson que dans le roman, dans la poesie que dans l'essai. Dans cette oeuvre complexe se melent evidences positives et implications metaphysiques; l'omnipresence du mystere engendre la conscience d'une unite substantielle du reel, liant la vie a la vision et l'abstraction a la matiere sensible. Aussi est-il possible de la rattacher moins a une tradition romantique a laquelle le theme de l'aventure semblait la consacrer qu'a celle du baroque dont elle reprend l'essentiel. Par la peinture, la poesie, l'ecriture s'etablit la relation avec les modalites ontologiques par laquelle le fini et l'infini se cotoient: c'est le sens de l'aventure litteraire de mac orlanAn attentive reading of p. Mac orlan based on the development of obsessionnel themes reveals some features which can not become obvious with a hasty approach. A sharp visual perception, an amazing analysis and foreknowledge, numerous directions taken by a creation the substance of which is made of memories and imagination : these are the main ways laid out by this writer who is as brilliant in songs as in novels, in poems as in essays. In this complex work, the concrete always interferes with metaphysical implications; the omnipresence of mystery breeds the conscience of a substantial unity of reality, binding life to vision and abstraction to perceptible material. So, it is possible to connect this work with a baroque tradition from which it takes the essential matter. By the painting, the poetry and the writing, the relationship is established with the ontological modalities, and thanks to it, the finite and the infinite keep close : it is the meaning of mac orlan's litterary adventure
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Majeed, Adnan. "TARMAC timing analysis resilient MAC protocol /." Diss., Online access via UMI:, 2007.
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Maher, Martina. "The death of Finn mac Cumaill." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/30591/.
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Finn mac Cumaill (Fionn Mac Cumhaill) has always been a popular figure in Gaelic tradition, coming to full prominence during the Early Modern period, as Fenian stories (tales of Finn and his fían, or fianna, known as fianaigecht in Old Irish and fiannaíocht in Modern Irish) become ever more popular in manuscript form. Despite the popularity that both Finn and the Finn Cycle have enjoyed in Gaelic literature, mentions of Finn's death are scant and tales recounting the event are even rarer. In the extant medieval Irish literature, the pinnacle of the corpus, Acallam na Senórach, not only holds the events in relative obscurity but its presentation of the circumstances of Finn's death may even be said to be conflicting. In looking at other tales in the fíanaigecht corpus, while we find a number of references to the fact than Finn dies, only a few depict his demise, namely Aided Finn and Tesmolta Cormaic ocus Aided Finn. To this short list of narratives detailing Finn's death and the events preceding it, we can add the tale designated 'The Chase of Síd na mBan Finn and the Death of Finn' (henceforth 'The Chase') preserved in a single manuscript, London, British Library, MS Egerton 1782. Although the tale breaks off with Finn still alive, albeit weary and bloodied and standing alone encircled by his adversaries, his death is a logical next element in the narrative, not least because there is repeated mention of a prophecy of his demise throughout the tale. This tale, which spans eight manuscript pages, seems to be the longest engagement with the idea of Finn's death in the medieval and Early Modern Irish corpora, yet has been the subject of very little scholarly investigation to date. This regrettable lacuna in scholarship on Fenian literature is the starting point for this thesis, which presents a three-pronged investigation of 'The Chase'. Following a fuller introduction to the topic in Chapter 1, the history of the manuscript is examined afresh in Chapter 2 as new evidence, particularly from the works of the scribe Muiris Ó Gormáin, has shed new light on the manuscript's history and on the tale of 'The Chase'. This is then employed to examine the section of the manuscript in which 'The Chase' is to be found, a section consisting of four tales thought to be from the now lost manuscript, Cín Dromma Snechtai, and four fíanaigecht tales. It is investigated if the unit may be considered a deliberate anthology and whether thematic and/or other concerns motivated the unit's compilation. Next, the study turns to the tale of 'The Chase' itself, examining its place within a continuum of traditions found in Old, Middle and Early Modern Irish treatments of Finn's death. Based on my own linguistic work on 'The Chase', a semi-diplomatic edition of which is included as an appendix to this thesis, it is demonstrated in Chapter 3 that the author of 'The Chase' seems to have been aware of several accounts of Finn's death, either those which are now extant or sources akin to them, and sought to bring together many of the elements present in other accounts of Finn's death in a single tale, perhaps in what was intended to be a comprehensive death tale for Finn. The various elements of the tale which resonate with the event of or events leading up to Finn's death, however, have not merely been cobbled together. Rather it is illustrated that the composition skilfully treats of the themes of death, prophecy and youth versus age, making regular allusion to the audience's presumed knowledge of other tales of the Fenian corpus, while adhering to the norms of earlier written fíanaigecht literature, a trait not always found in Early Modern tales of the Finn Cycle. The last study which forms part of this thesis, Chapter 4, arose from the recognition that although 'The Chase' appears to be the longest extant engagement with Finn's death, there exists no study that details what material on Finn's death has circulated in the modern period. This section provides a comprehensive overview of modern engagements with Finn's death in post-1650 manuscripts and folklore collections. All the modern accounts that I have found to date in which Finn's death is recounted or in which it is presumed that Finn is dead, which are usually mentions of Finn's grave, are therefore identified, presented, and where applicable, translated. While it becomes clear that no other engagement with Finn's demise across the eleven centuries during which his death excited the Gaelic imagination is as long or as complex as 'The Chase', common or notable motifs in the modern accounts are identified, and similarities between the different treatments of Finn's death in the modern narratives are discussed. It is shown that a small number of the motifs and events treated in the medieval accounts of Finn’s death and in 'The Chase' are also treated in the modern tales of his demise, thus indicating some thematic continuity between medieval and modern approaches to relating how Finn died. With this in mind, some further relationships between the modern accounts of Finn's death and other medieval and modern Fenian literature are explored.
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Liu, Shuyang. "Movable frame hybrid MAC : a multi-MAC protocol for wireless software radios in multi-rate multimedia applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ54319.pdf.
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Albrecht, Michael. "Das System der US-amerikanischen Wohnungsfinanzierung : Fannie Mae und Freddie Mac als Instrumente staatlicher Wohnungspolitik /." Frankfurt am Main [u.a.] : Lang, 2004. http://www.gbv.de/dms/zbw/372974007.pdf.
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Katila, Charles Jumaa. "Mac protocols for linear wireless (sensor) networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7626/.
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Wireless sensor networks (WSNs) consist of a large number of sensor nodes, characterized by low power constraint, limited transmission range and limited computational capabilities [1][2].The cost of these devices is constantly decreasing, making it possible to use a large number of sensor devices in a wide array of commercial, environmental, military, and healthcare fields. Some of these applications involve placing the sensors evenly spaced on a straight line for example in roads, bridges, tunnels, water catchments and water pipelines, city drainages, oil and gas pipelines etc., making a special class of these networks which we define as a Linear Wireless Network (LWN). In LWNs, data transmission happens hop by hop from the source to the destination, through a route composed of multiple relays. The peculiarity of the topology of LWNs, motivates the design of specialized protocols, taking advantage of the linearity of such networks, in order to increase reliability, communication efficiency, energy savings, network lifetime and to minimize the end-to-end delay [3]. In this thesis a novel contention based Medium Access Control (MAC) protocol called L-CSMA, specifically devised for LWNs is presented. The basic idea of L-CSMA is to assign different priorities to nodes based on their position along the line. The priority is assigned in terms of sensing duration, whereby nodes closer to the destination are assigned shorter sensing time compared to the rest of the nodes and hence higher priority. This mechanism speeds up the transmission of packets which are already in the path, making transmission flow more efficient. Using NS-3 simulator, the performance of L-CSMA in terms of packets success rate, that is, the percentage of packets that reach destination, and throughput are compared with that of IEEE 802.15.4 MAC protocol, de-facto standard for wireless sensor networks. In general, L-CSMA outperforms the IEEE 802.15.4 MAC protocol.
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Norén, Per. "Physical layer interface for IEEE 802.11 MAC." Thesis, Linköping University, Department of Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1383.
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There are several standards for wireless communication. People that are involved in computers and networking recognize names like Bluetooth, HiperLAN and IEEE 802.11. A fundamental part of an IEEE 802.11 node is the Medium Access Controller. It establishes and controls communication with other nodes, using a physical layer unit. This is the work that was carried out as a master thesis project at Ericsson Microelectronics. The main goal was to design, implement and evaluate a hardware interface between the MAC and the physical layer. An important part of the work was to find a suitable partition scheme for hardware and software and to achieve this, an investigation of processor-cycles usage was carried out to support design decisions. The hardware/software partition resulted in hardware-functionality for decode of received frames and automatic transmission of acknowledge frames.
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Alhakami, Wajdi. "Secure MAC protocols for cognitive radio networks." Thesis, University of Bedfordshire, 2016. http://hdl.handle.net/10547/621831.
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With the rapid increase in wireless devices, an effective improvement in the demand of efficient spectrum utilisation for gaining better connectivity is needed. Cognitive Radio (CR) is an emerging technology that exploits the inefficient utilisation of the unused spectrum dynamically. Since spectrum sharing is responsible for coordinating channels’ access for Cognitive Users (CUs), the Common Control Channel (CCC) is one of the existing methods used to exchange the control information between CUs. However, the unique characteristics and parameters of Cognitive Radio Networks (CRNs) present several possible threats targeting spectrum sensing, spectrum management, spectrum sharing, and spectrum mobility leading to the deterioration of the network performance. Thus, protection and detection security mechanisms are essential to maintaining the CRNs. This thesis presents a novel decentralised CR MAC protocol that successfully utilises the unused portion of the licensed band. The protocol achieves improved performance; communication time and throughput when compared to two benchmark protocols. Less communication time and higher throughput are accomplished by the protocol due to performing fast switching to the selected available data channel for initiating data transmission. The proposed protocol is then extended to two different versions based on two authentication approaches applied to it; one using Digital Signature and another is based on Shared-Key. The two proposed secure protocols address the security requirements in CRNs leading to subsequent secure communication among CUs. The protocols function effectively in providing defence against several attacks related to the MAC layer such as; Spectrum Sensing Data Manipulation/Falsification, Data Tempering and Modification, Jamming attacks, Eavesdropping, Forgery and Fake control information attacks, MAC address spoofing, and unauthorised access attacks. The associated security algorithms ensure the successful secure communication between CUs in a cooperative approach. Moreover, the security protocols are investigated and analysed in terms of security flows by launching unauthorised access and modification attacks on the transmitted information. The testing results demonstrated that two protocols perform successful detection of threats and ensure secure communication in CRNs.
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Elshabrawy, Tallal O. "MAC architecture for broadband satellite access systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/MQ47825.pdf.
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Cheng, Liang. "IEEE 802.15.4 MAC Protocol Study and Improvement." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/cs_diss/25.
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IEEE 802.15.4 is a standard used for low rate personal area networks (PANs). It offers device level connectivity in applications with limited ower and relaxed throughput requirements. Devices with IEEE 802.15.4 technology can be used in many potential applications, such as home networking, industry/environments monitoring, healthcare equipments, etc, due to its extremely low power features. Although the superframe beacons play the key role in synchronizing channel access in IEEE 802.15.4, they are sources for energy inefficiency. This research focuses on exploring how to optimize the beacons, and designing novel schemes to distribute the information that are supposed to be delivered to a subset of PAN devices. In this work, an acknowledgement based scheme is proposed to reduce the energy consumption in the distribution of guaranteed time slot (GTS) descriptors. Based on the observation that the superframe beacon frame has global impact on all PAN devices, an energy-efficient channel reservation scheme is presented to deliver the information (GTS descriptors and pending addresses). In addition, the problem of channel underutilization is studied in the contention free period. To address the problem, a new GTS allocation scheme is proposed to improve the bandwidth utilization.
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Koh, Kenneth Johannesen. "Analysis of Key Industrial WSN MAC Protocols." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for telematikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27346.
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This paper looks at two MAC protocols for wireless sensor networksfor use in industrial applications developed at the Ubicom Lab, at theUniversity of Ulsan. A theoretical comparison of the MAC protocolsare performed to understand more about the benefits and downsidesto both of them, and experimental scenarios to validate the theoreticalanalysis are suggested. Theoretical analysis suggests that BigMAC hasan advantage in environments with high interference and frequent linkbreaks, while I-MAC has an advantage when the network topology isstable.
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O, Machain Padraig Carthach. "Poems by Fearghal Og Mac an Bhaird." Thesis, University of Edinburgh, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314414.
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Xi, Weihua. "MAC enhancements for high speed wireless LANs." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446178.
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Guibovich, Pérez Pedro M. "Felipe Mac Gregor, S.J.: una aproximación biobibliográfica." Pontificia Universidad Católica del Perú - Departamento de Humanidades, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/112951.
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Basadre, Grohmann Jorge. "En honor del P. Felipe Mac Gregor." Pontificia Universidad Católica del Perú - Departamento de Humanidades, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/112737.
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Nikolaïdou, Margarita-Matthildi. "L'exotisme dans l'œuvre de Pierre Mac Orlan." Paris 4, 1997. http://www.theses.fr/1997PA040117.
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Pierre Mac Orlan n'éveille pas le sentiment exotique en se fondant sur l'éloignement, malgré la diversité des villes et la pluralité des noms géographiques figurant dans ses œuvres; pour lui, le pittoresque réside au sein même du familier. Qualifie de "fantastique social", son exotisme dépeint l'aventure intérieure de ses contemporains confrontés à un inconnu irrationnel qui se laisse surprendre aussi bien dans l'âme de ses personnages que dans les lieux où se déroule l'action. Il s'agit d'une exploration du monde à la fois fascinant et menaçant des années 20 et des années 30, d'un voyage imaginaire entrepris au moyen d'une écriture poétique qui sert d'exorcismePierre Mac Orlan does not arouse the exotic feeling based on distance, despite the diversity of cities and the plurality of geographical names figuring in his works. For him the picturesque resides within the familiar itself characterized by "fantastique social" exoticism depicts the inner adventures of his contemporaries conforming to an irrational unknown that exists in the souls of his characters as well as in the places where the actions take place. It is about an exploration of the world of the 20s and 30s which is at the same time fascinating and threatening, about an imaginary journey taken by means of a poetic writing that serves as an exorcism
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Světlík, Martin. "Integrace počítačů Apple Mac do firemního prostředí." Master's thesis, Vysoká škola ekonomická v Praze, 2016. http://www.nusl.cz/ntk/nusl-261954.
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Corporate informatics has undergone a number of changes in past few years. Used devices are becoming more independent from the OS, they rely more on provided services and the level of security. Cloud technologies are increasingly growing in significance and a large number of companies offer their employees BYOD (Bring Your Own Device). This thesis focuses on integration of Apple Mac computers into corporate environments, based on analysis of contemporary approaches and possibilities of dealing with integration. An important part of this thesis is research of chosen implemented solutions in the Czech republic. From both parts of this thesis it then offers recommendations, which are based on practical experience of companies that widely use and deal with integration of Mac computers.
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Brownfield, Michael I. "Energy-efficient Wireless Sensor Network MAC Protocol." Diss., This resource online, 2006. http://scholar.lib.vt.edu/theses/available/etd-04102006-170423/.
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Ge, Ye. "QoS provisioning for IEEE 802.11 MAC protocols." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1095441321.
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Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xiii, 97 p.; also includes graphics (some col.). Includes bibliographical references (p. 94-97).
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Toldov, Viktor. "Adaptive MAC layer for interference limited WSN." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10002/document.
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A l'époque de l'Internet des Objets, le nombre de dispositifs communicants ne cesse d'augmenter. Souvent, les objets connectés utilisent des bandes de fréquences « industriel, scientifique et médical (ISM) » pour effectuer les communications. Ces bandes sont disponibles sans licence, ce qui facilite le déploiement de nouveaux objets connectés. Cependant, cela mène aussi au fait que le niveau d'interférences augmente dans les bandes ISM. Les interférences ont non seulement un impact négatif sur la qualité de service, mais aussi elles causent des pertes de messages couteuses en énergie, ce qui est particulièrement nocif pour les nœuds capteurs souvent limités en énergie. Dans cette thèse, l'impact des interférences sur la consommation énergétique des nœuds est étudié expérimentalement. Les résultats de ces expérimentations sont utilisés pour estimer la durée de vie des nœuds en fonction de différents niveaux d’interférence subis. Puis, un algorithme de Radio Cognitive (RC) basé sur la technique d’ échantillonnage de Thompson est proposé et évalué par la simulation et implémentation. Les résultats montrent que l'approche proposée trouve le meilleur canal plus vite que les autres techniques. De plus, une extension multi sauts pour RC est proposée et évaluée par expérimentation lors d'une compétition EWSN Dependability Competition. Finalement, le protocole adaptatif WildMAC est proposé pour le cas d'usage du projet LIRIMA PREDNET qui consiste à surveiller des animaux sauvages. Les performances sont évaluées par simulation avec le simulateur WSNet. Les résultats montrent que la solution proposée respecte les contraintes imposées par le projet PREDNET dans la zone cibléeIn the era of the Internet of Things, the number of connected devices is growing dramatically. Often, connected objects use Industrial, Scientific and Medical radio bands for communication. These kinds of bands are available without license, which facilitates development and implementation of new connected objects. However, it also leads to an increased level of interference in these bands. Interference not only negatively affects the Quality of Service, but also causes energy losses, which is especially unfavorable for the energy constrained Wireless Sensor Networks (WSN). In the present thesis the impact of the interference on the energy consumption of the WSN nodes is studied experimentally. The experimental results were used to estimate the lifetime of WSN nodes under conditions of different levels of interference. Then, a Thompson sampling based Cognitive Radio (CR) adaptive solution is proposed and evaluated via both, simulation and hardware implementation. Results show that this approach finds the best channel quicker than other state of the art solutions. An extension for multihop WSN was proposed for this CR solution and evaluated by hardware implementation in the framework of EWSN Dependability Competition. Finally, an adaptive WildMAC MAC layer protocol is proposed for the usecase of the LIRIMA PREDNET wildlife animal tracking project. Obtained field range test data were used to theoretically estimate cell densities and deployment zone coverage in this Low Power Widea Area Network (LPWAN). Then performance of the protocol was evaluated in WSNet simulation. The results show performance that allows to respect PREDNET project requirements with the given coverage
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Michálek, Tomáš. "Vývoj MAC protokolu pro bezdrátové senzorové sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-242186.
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The work focuses on introduction to the topic of wireless sensor networks and brings readers the various aspects of problem solving in these networks. Work is closely focused on the energy performance when communicating between devices on a network and discusses the causes of excessive energy consumption. It also addresses the mechanisms for saving energy and is also engaged today protocols that its contribution to proposing solutions to problems. The author had also proposes an adapted protocol, based on lessons learned from previous theoretical sources.
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Long, Hua. "Research routing and MAC based on LEACH and S-MAC for energy efficiency and QoS in wireless sensor network." Thesis, University of Huddersfield, 2013. http://eprints.hud.ac.uk/id/eprint/23739/.
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The wireless sensor is a micro-embedded device with weak data processing capability and small storage space. These nodes need to complete complex jobs, including data monitoring, acquisition and conversion, and data processing. Energy efficiency should be considered as one of the important aspects of the Wireless Sensor Network (WSN) throughout architecture and protocol design. At the same time, supporting Quality of Service (QoS) in WSNs is a research field, because the time-sensitive and important information is expected for the transmitting to to the sink node immediately. The thesis is supported by the projects entitled “The information and control system for preventing forest fires”, and “The Erhai information management system”, funded by the Chinese Government. Energy consumption and QoS are two main objectives of the projects. The thesis discusses the two aspects in route and Media Access Control (MAC). For energy efficiency, the research is based on Low Energy Adaptive Clustering Hierarchy (LEACH) protocol. LEACH is a benchmark clustering routing protocol which imposes upon cluster heads to complete a lot of aggregation and relay of messages to the base-station. However, there are limitations in LEACH. LEACH does not suit a wide area in clustering strategy and multi-hop routing. Moreover, routing protocols only focus on one factor, combining the clustering strategy and multi-hop routing mechanism were not considered in routing protocol for performance of network. QoS is supported by the MAC and routing protocol. Sensor MAC(S-MAC) makes the use of the periodically monitoring / sleeping mechanism, as well as collision and crosstalk avoidance mechanism. The mechanism reduces energy costs. Meanwhile, it supports good scalability and avoids the collision. However, the protocols do not take the differentiated services. For supporting QoS,A new route protocol needs to be designed and realized on embed platforms, which has WIFI mode and a Linux operation system to apply on the actual system. This research project was conducted as following the steps: A new protocol called RBLEACH is proposed to solve cluster on a widely scale based on LEACH. The area is divided into a few areas, where LEACH is improved to alter the selecting function in each area. RBLEACH creates routes selected by using a new algorithm to optimize the performance of the network. A new clustering method that has been developed to use several factors is PS-ACO-LEACH. The factors include the residual energy of the cluster head and Euclidean distances between cluster members and a cluster head. It can optimally solve fitness function and maintain a load balance in between the cluster head nodes, a cluster head and the base station. Based on the “Ant Colony” algorithm and transition of probability, a new routing protocol was created by “Pheromone” to find the optimal path of cluster heads to the base station. This protocol can reduce energy consumption of cluster heads and unbalanced energy consumption. Simulations prove that the improved protocol can enhance the performance of the network, including lifetime and energy conservation. Additionally, Multi Index Adaptive Routing Algorithm (MIA-QR) was designed based on network delay, packet loss rate and signal strength for QoS. The protocol is achieved by VC on an embedded Linux system. The MIA-QR is tested and verified by experiment and the protocol is to support QoS. Finally, an improved protocol (SMAC -SD) for wireless sensor networks is proposed, in order to solve the problem of S-MAC protocol that consider either service differentiation or ensure quality of service. According to service differentiation, SMAC-SD adopts an access mechanism based on different priorities including the adjustment of priority mechanisms of channel access probability, channel multi-request mechanisms and the configuring of waiting queues with different priorities and RTS backoff for different service, which makes the important service receive high channel access probability, ensuring the transmission quality of the important service. The simulation results show that the improved protocol is able to gain amount of important service and shortens the delay at the same time. Meanwhile, it improves the performance of the network effectively.
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Al-Mousa, Yamin Samir. "MAC/routing design for under water sensor networks /." Online version of thesis, 2007. http://hdl.handle.net/1850/4496.
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Masrub, Abdullah Ashur. "Cognitive MAC protocols for mobile ad-hoc networks." Thesis, Brunel University, 2013. http://bura.brunel.ac.uk/handle/2438/7621.
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The term of Cognitive Radio (CR) used to indicate that spectrum radio could be accessed dynamically and opportunistically by unlicensed users. In CR Networks, Interference between nodes, hidden terminal problem, and spectrum sensing errors are big issues to be widely discussed in the research field nowadays. To improve the performance of such kind of networks, this thesis proposes Cognitive Medium Access Control (MAC) protocols for Mobile Ad-Hoc Networks (MANETs). From the concept of CR, this thesis has been able to develop a cognitive MAC framework in which a cognitive process consisting of cognitive elements is considered, which can make efficient decisions to optimise the CR network. In this context, three different scenarios to maximize the secondary user's throughput have been proposed. We found that the throughput improvement depends on the transition probabilities. However, considering the past information state of the spectrum can dramatically increases the secondary user's throughput by up to 40%. Moreover, by increasing the number of channels, the throughput of the network can be improved about 25%. Furthermore, to study the impact of Physical (PHY) Layer errors on cognitive MAC layer in MANETs, in this thesis, a Sensing Error-Aware MAC protocols for MANETs has been proposed. The developed model has been able to improve the MAC layer performance under the challenge of sensing errors. In this context, the proposed model examined two sensing error probabilities: the false alarm probability and the missed detection probability. The simulation results have shown that both probabilities could be adapted to maintain the false alarm probability at certain values to achieve good results. Finally, in this thesis, a cooperative sensing scheme with interference mitigation for Cognitive Wireless Mesh Networks (CogMesh) has been proposed. Moreover, a prioritybased traffic scenario to analyze the problem of packet delay and a novel technique for dynamic channel allocation in CogMesh is presented. Considering each channel in the system as a sub-server, the average delay of the users' packets is reduced and the cooperative sensing scenario dramatically increases the network throughput 50% more as the number of arrival rate is increased.
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Majid, M. I. "Frequency planning for clustered joint processing cellular MAC." Thesis, University of Surrey, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529428.
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Shah, Munam Ali. "A novel MAC protocol for cognitive radio networks." Thesis, University of Bedfordshire, 2013. http://hdl.handle.net/10547/301090.
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The scarcity of bandwidth in the radio spectrum has become more vital since the demand for wireless applications has increased. Most of the spectrum bands have been allocated although many studies have shown that these bands are significantly underutilized most of the time. The problem of unavailability of spectrum bands and the inefficiency in their utilization have been smartly addressed by the cognitive radio (CR) technology which is an opportunistic network that senses the environment, observes the network changes, and then uses knowledge gained from the prior interaction with the network to make intelligent decisions by dynamically adapting transmission characteristics. In this thesis, recent research and survey about the advances in theory and applications of cognitive radio technology has been reviewed. The thesis starts with the essential background on cognitive radio techniques and systems and discusses those characteristics of CR technology, such as standards, applications and challenges that all can help make software radio more personal. It then presents advanced level material by extensively reviewing the work done so far in the area of cognitive radio networks and more specifically in medium access control (MAC) protocol of CR. The list of references will be useful to both researchers and practitioners in this area. Also, it can be adopted as a graduate-level textbook for an advanced course on wireless communication networks. The development of new technologies such as Wi-Fi, cellular phones, Bluetooth, TV broadcasts and satellite has created immense demand for radio spectrum which is a limited natural resource ranging from 30KHz to 300GHz. For every wireless application, some portion of the radio spectrum needs to be purchased, and the Federal Communication Commission (FCC) allocates the spectrum for some fee for such services. This static allocation of the radio spectrum has led to various problems such as saturation in some bands, scarcity, and lack of radio resources to new wireless applications. Most of the frequencies in the radio spectrum have been allocated although many studies have shown that the allocated bands are not being used efficiently. The CR technology is one of the effective solutions to the shortage of spectrum and the inefficiency of its utilization. In this thesis, a detailed investigation on issues related to the protocol design for cognitive radio networks with particular emphasis on the MAC layer is presented. A novel Dynamic and Decentralized and Hybrid MAC (DDH-MAC) protocol that lies between the CR MAC protocol families of globally available common control channel (GCCC) and local control channel (non-GCCC). First, a multi-access channel MAC protocol, which integrates the best features of both GCCC and non-GCCC, is proposed. Second, an enhancement to the protocol is proposed by enabling it to access more than one control channel at the same time. The cognitive users/secondary users (SUs) always have access to one control channel and they can identify and exploit the vacant channels by dynamically switching across the different control channels. Third, rapid and efficient exchange of CR control information has been proposed to reduce delays due to the opportunistic nature of CR. We have calculated the pre-transmission time for CR and investigate how this time can have a significant effect on nodes holding a delay sensitive data. Fourth, an analytical model, including a Markov chain model, has been proposed. This analytical model will rigorously analyse the performance of our proposed DDH-MAC protocol in terms of aggregate throughput, access delay, and spectrum opportunities in both the saturated and non-saturated networks. Fifth, we develop a simulation model for the DDH-MAC protocol using OPNET Modeler and investigate its performance for queuing delays, bit error rates, backoff slots and throughput. It could be observed from both the numerical and simulation results that when compared with existing CR MAC protocols our proposed MAC protocol can significantly improve the spectrum utilization efficiency of wireless networks. Finally, we optimize the performance of our proposed MAC protocol by incorporating multi-level security and making it energy efficient.
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Baines, Roger W. "'Inquietude' in the work of Pierre Mac Orlan." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243664.
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SaÌmano-Robles, Ramiro. "MAC/PHY cross-layer design for wireless networks." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445844.
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Waters, Margaret Fiona. "Enzymes of RNA metabolism in Nostoc sp. MAC." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329409.
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Malik, Hassan. "Distributed MAC protocol for full-duplex wireless networks." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/846235/.
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Full-duplex (FD) communication is considered to be a promising technology to address the problem of radio spectrum congestion due to the increasing demand for wireless communication services. This thesis investigates the problem of asymmetric data flow between downlink and uplink in a system with symmetric radio resource allocation, i.e. FD. The aim is to devise a model by exploiting the coupling nature of FD downlink and uplink transmission powers to maximise the downlink data rate while ensuring the quality of service (QoS) of uplink transmission. Whilst the aim is to maximise the spectrum efficiency gain that can be achieved with FD enabled cellular networks, this thesis presents D-MAC: a novel distributed MAC protocol. D-MAC allows interfering nodes to cooperate and implement an interuser interference estimation mechanism to gather the interference information with minimum overhead. Furthermore, D-MAC includes interference aware joint user equipment (UE) scheduling and power allocation methods. Computing the optimal resource allocation and transmission rates is non-linear, non-convex combinatorial optimisation and achieving a globally optimal solution is not possible in practice. Therefore, D-MAC uses a low complexity iterative approach for resource allocation and ensures that channel bandwidth is shared fairly across all UEs. Finally, a detailed evaluation of D-MAC performance is presented and compared to the half-duplex (HD) system, FD system with round robin and FD system with exhaustive search. It is shown that the D-MAC achieves as much as 62% throughput improvement compared to an HD system with symmetric traffic model and 49% with asymmetric traffic model in an outdoor multi-cell scenario under the limits of practical self-interference cancellation. Further, D-MAC also reduces the round-trip propagation delay, involved from the point at which the UE sends the request to the base station to the point at which the UE realize the result of contention.
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Ferreira, Patrícia Alexandra Mendes. "MAC." Dissertação, 2014. http://hdl.handle.net/10216/77114.
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Naito, Hisashi, and 久資 内藤. "Mac OS X - Mac OS X のネットワーク -." 2004. http://hdl.handle.net/2237/108.
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Tunc, Muharrem Ali Cetinkaya Coskun. "Service differentiation via cooperative MAC protocol (SD-MAC)." Diss., 2005. http://il.proquest.com/products_umi/dissertations.
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Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering."December 2005." Title from PDF title page (viewed on April 19, 2007). Thesis adviser: Coscun Cetinkaya. UMI Number: AAT 1436584 Includes bibliographic references (leaves 57-60).
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Tunc, Muharrem Ali. "Service differentiation via cooperative MAC protocol (SD-MAC)." Thesis, 2005. http://hdl.handle.net/10057/774.
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With the recent advances in wireless communications and networking area, it has been a great challenge for researchers to improve a medium access protocol for providing an efficient service differentiation in wireless ad hoc, sensor and wireless Local Area Networks among different priority class applications that require high goodput, short term fairness, low delay and delay jitter. IEEE 802.11 Static MAC protocol assigns different Arbitration Inter Frame Space (AIFS) durations for different priority classes to provide service differentiation. However, it is subject to a significant goodput degradation when the high priority class is low. On the other hand, IEEE 802.11e Dynamic MAC protocol employs different AIFSs, (CW min ,CW max ) pairs and contention window expansion factors (PFs) for different classes to support differentiated quality of service levels. Yet, it can not protect high priority class traffic from greedy sources in case of a heavy network load. The proposed protocol SD-MAC, Service Differentiation via CMAC, uses Cooperative MAC protocol (CMAC) as a basis protocol and can easily be implemented using IEEE 802.11e and CMAC. In SD-MAC, each node has to change its back-off counter based on both its own packet’s priority level and the priority level of the transmitted packet. If a node hears an ongoing transmission of a packet of higher priority than its own, it has to increase its back-off counter linearly. Besides, if it hears an ongoing transmission of a packet of lower priority than its own, it has to decrement its back-off counter exponentially. The simulation results indicate that, SD-MAC is a short term fair protocol which performs well in all network scenarios providing high network goodput, short term fairness and large admissible region.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering.
"December 2005."
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Naito, Hisashi, and 久資 内藤. "Mac OS X - Mac OS X Serverのススメ -." 2004. http://hdl.handle.net/2237/113.
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