Download or read book Reconfigurable Medium Access Control Protocols for Wireless Networks written by and published by . This book was released on 2014 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Medium Access Control MAC Protocol for Reconfigurable Wireless Networks written by Wiwat Ruengmee and published by . This book was released on 1997 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reconfigurable Medium Access Control Solutions for Resource Constrained Wireless Networks written by Noemí Arbós Linio and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless Sensor Networks (WSNs) consist of several autonomous resource constrained sensor nodes distributed over a geographical area. The sensor nodes can measure, for instance humidity, temperature or vibration. Therefore, these networks can be deployed in many different types of dynamic environments. Traditionally, Medium Access Control (MAC) protocols used in WSNs are implemented in a monolithic fashion with tight coupling to the underlying hardware. Although this approach of design and implementation can usually make full use of the capability of the underlying hardware, theMACsolution is static and provides satisfying performance only under the pre-defined conditions. However, as application requirements and network conditions may change, adaptability and reconfigurability of MAC protocols are desired. In this thesis, we have designed and implemented a toolchain which enables runtimeMACprotocol reconfiguration for WSNs. The toolchain has been implemented in TinyOS using component-based design and hardware independence, allowing users to develop MAC solutions for WSNs, execute and reconfigure them in many platforms. Finally, a user is able to interact with the sensor node through a user interface developed in Java. Furthermore, this toolchain has been enhanced by the features introduced in [1] to enable also simplifying the design of MAC protocols, allowing non-specific sensors users to implement and finally execute and reconfigure them in sensor nodes. The toolchain has been compared to monolithic implementations in terms of execution time and reconfiguration costs. The results show that the toolchain enables fast runtime reconfiguration of MAC protocols with an quantify execution time overhead. Our toolchain saves from 26% up to 98% the time needed to reconfigure a MAC protocol compared to the monolithic approach.

Download or read book Automated Design of Optimal Medium Access Control Protocols for Wireless Networking written by Jian Zhen and published by . This book was released on 2014 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a framework for the automated design of optimal Medium Access Control (MAC) protocols for wireless networks.

Download or read book MAC Scheme for Reconfigurable Wireless Networks written by Rakesh K. Shah and published by . This book was released on 1996 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analytical Modeling of Medium Access Control Protocols in Wireless Networks written by Marcelo Menezes Carvalho and published by . This book was released on 2006 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new modeling framework is introduced for the analytical study of medium access control (MAC) protocols operating in multihop wireless ad hoc networks, i.e., wireless networks characterized by the lack of any pre-existent infrastructure and where participating devices must cooperatively provide the basic functionalities that are common to any computer network. The proposed modeling framework focuses on the interactions between the physical (PHY) and MAC layers, and on the impact that each node has on the dynamics of every other node in the network. To account for the effects of both cross-layer interactions and the interference among all nodes, a novel linear model is introduced with which topology and PHY/MAC-layer aspects are naturally incorporated in what we define as interference matrices. A key feature of the model is that nodes can be modeled individually, i.e., it allows a per-node setup of many layer-specific parameters. Moreover, no spatial probability distribution or special arrangement of nodes is assumed; the model allows the computation of individual (per-node) performance metrics for any given network topology and radio channel model.

Download or read book Novel Medium Access Control MAC Protocols for Wireless Sensor and Ad Hoc Networks WSANs and Vehicular Ad Hoc Networks VANETs written by Md Kowsar Hossain and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MAC Protocol Design in Full Duplex Enabled Wireless Networks written by Liqun Fu and published by Springer. This book was released on 2024-05-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book thoroughly examines the design of full-duplex medium access control (MAC) protocols in wireless networks. It is organized into three main sections: (a) Fundamentals and preliminaries of full-duplex communications, (b) A comprehensive review of the existing full-duplex MAC protocols, and (c) Designs of full-duplex MAC protocols in three typical wireless networks, i.e., wireless local access networks (WLANs), multi-hop networks and millimeter-wave networks. Also, the authors extensively address key challenges in these three wireless full-duplex networks, such as the hidden-node problem, accumulative interference and deafness and blockage problems. Solutions of these challenges are meticulously devised to enhance the overall network performance. The wireless full-duplex communication technique, facilitating simultaneous transmission and reception within the same frequency band, holds immense potential for enhancing spectrum efficiency and network capacity. It positions itself as a pivotal technology in the sixth-generation (6G) networks. This book provides a comprehensive review and in-depth exploration of full-duplex MAC design across various networks, encompassing WLANs, multi-hop networks and millimeter-wave networks. Acknowledging the challenges faced by full-duplex WLANs, particularly the hidden-node problem, it also the introduces a pioneering hidden-node-free design and a MAC protocol design, which features a full-duplex enhanced carrier-sensing mechanism. Addressing the need to augment end-to-end throughput in multi-hop networks employing full-duplex relaying, the authors present an analytical model for end-to-end throughput and propose a multi-hop full-duplex MAC protocol designed to optimize network performance. Furthermore, the exploration extends to full-duplex millimeter-wave networks, delving into issues of deafness and blockage. A directional full-duplex MAC protocol is introduced to enhance network capacity and mitigate blockage problems. This book concludes by outlining prospective research directions within the related fields of study and offers valuable insights for future exploration. This book targets researchers and advanced level students in computer science and electrical engineering. It also caters to professionals engaged in the field of wireless networks, full-duplex systems, protocol design and network optimization will also buy this book.

Download or read book Mobility based routing overhead management in reconfigurable wireless ad hoc networks written by Wilfred Githuka Gikaru and published by Cuvillier Verlag. This book was released on 2004 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Protocol Design and Analysis for Cooperative Wireless Networks written by Wei Song and published by Springer. This book was released on 2016-11-03 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the design and analysis of protocols for cooperative wireless networks, especially at the medium access control (MAC) layer and for crosslayer design between the MAC layer and the physical layer. It highlights two main points that are often neglected in other books: energy-efficiency and spatial random distribution of wireless devices. Effective methods in stochastic geometry for the design and analysis of wireless networks are also explored. After providing a comprehensive review of existing studies in the literature, the authors point out the challenges that are worth further investigation. Then, they introduce several novel solutions for cooperative wireless network protocols that reduce energy consumption and address spatial random distribution of wireless nodes. For each solution, the book offers a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate the analysis and examine the performance under various conditions. The last section of this book reveals several potential directions for the research on cooperative wireless networks that deserve future exploration. Researchers, professionals, engineers, and consultants in wireless communication and mobile networks will find this book valuable. It is also helpful for technical staff in mobile network operations, wireless equipment manufacturers, wireless communication standardization bodies, and governmental regulation agencies.

Download or read book A Simulation Study of Medium Access Control Protocols of Wireless Networks written by Rohan Uddhav Patel and published by . This book was released on 2008 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Medium Access Protocol MAC Design for Wireless Multi hop Ad Hoc and Sensor Networks written by Afef Sayadi and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless multi-hop ad hoc and sensor networks provide a promising solution to ensure ubiquitous connectivity for the Future Internet. Good network connectivity requires designing a reliable Medium Access Control (MAC) protocol, which is a challenging task in the ad hoc and sensor environments. The broadcast and shared nature of the wireless channel renders the bandwidth resources limited and expose the transmissions to relatively high collisions and loss rates. The necessity to provide guaranteed Quality of Service (QoS) to the upper layers triggered the design of conflict-free MAC protocols. The TDMA synchronization constraint is basically behind the rush of MAC protocol design based on a fixed frame size. This design shows inflexibility towards network variations and creates a network dimensioning issue that leads to a famine risk in case the network is under-dimensioned, and to a waste of resources, otherwise. Moreover, the alternative dynamic protocols provide more adaptive solutions to network topology variations at the expense of a fair access to the channel. Alongside with the efficient channel usage and the fair medium access, reducing the energy consumption represents another challenge for ad hoc and sensor networks. Solutions like node activity scheduling tend to increase the network lifetime while fulfilling the application requirements in terms of throughput and delay, for instance. Our contributions, named OSTR and S-OSTR, address the shortcomings of the medium access control protocol design in the challenging environment of wireless multi-hop ad hoc and sensor networks, respectively. For OSTR the idea consists in adopting a dynamic TDMA frame size that increases slot-by-slot according to the nodes arrival/departure to/from the network, and aiming to achieve a minimum frame size. For this end, OSTR couples three major attributes: (1) performing slot-by-slot frame size increase, (2) providing a spatial reuse scheme that favors the reuse of the same slot if possible, (3) and ensuring an on-demand frame size increase only according to the node requirements in terms of throughput. To tackle different frame sizes co-existence in the network, OSTR brings a cooperative solution that consists in fixing an appointment, a date when the frame size in the network is increased. Concerning S-OSTR, it is an amendment of OSTR for wireless sensor networks. It brings the idea of a dynamic active period, since it deploys a dynamic frame size that is built slot-by-slot according to nodes arrival to the network. S-OSTR enforces the slot-by-slot frame size increase by a node activity scheduling to prolong the inactivity period in the network, and hence prolong the overall network lifetime for wireless sensor networks. Our contributions are both based on the new dynamic TDMA frame size increase that consists in increasing the frame size slot-by-slot aiming to achieve a shorter frame size, and hence improve the channel utilization, and reduce the energy consumption. The performance analysis of OSTR and S-OSTR shows that they present good potentials to support QoS requirements, to provide energy-efficiency, to ensure fair medium access, to accommodate network topology changes and finally, to enhance robustness against scalability. The impact of this new TDMA frame size increase technique on the medium access control protocol performance is highlighted through multiple simulations of OSTR and S-OSTR. Multiple comparative studies are also handled to point out the effectiveness of this new technique and the soundness of our contributions.

Download or read book WIRELESS SENSOR NETWORKS ARCHITECTURES AND PROTOCOLS written by Dr. Atul Srivastava and published by Xoffencerpublication. This book was released on 2023-08-07 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welcome to the fascinating world of Wireless Sensor Networks (WSNs)! In recent years, WSNs have emerged as one of the most promising and dynamic fields of research and application, revolutionizing various domains such as environmental monitoring, industrial automation, healthcare, agriculture, and many more. These networks consist of a large number of tiny, autonomous devices called sensors, which collaborate to sense and gather data from the environment, process it, and communicate wirelessly to accomplish a wide range of tasks. This book is designed to be a comprehensive guide that explores the architecture and protocols employed in Wireless Sensor Networks. Whether you are a student, researcher, or professional in the field, we believe this book will serve as an invaluable resource, providing you with a solid understanding of the fundamental concepts, challenges, and advancements in this dynamic domain. The primary objective of this book is to provide a holistic view of WSN architecture and protocols. We start by introducing the basic components and principles of WSNs, including the sensor nodes, base stations, and the communication infrastructure. We delve into the various layers of the WSN protocol stack, from the physical layer to the application layer, highlighting the functions and protocols utilized at each level. We discuss the techniques and protocols employed to mitigate these challenges, including energy-efficient routing, data aggregation, medium access control, and security mechanisms. We have aimed to present the material in a readerfriendly manner, with a balance between theoretical concepts and practical applications. Real-world examples, case studies, and illustrations are provided throughout the book to help readers grasp the concepts and envision the potential applications of WSNs in various domains. We would like to express our gratitude to the research community, whose relentless efforts and groundbreaking work have paved the way for the development and advancement of WSNs. We hope this book will contribute to further exploration, innovation, and collaboration in this exciting field.

Download or read book Medium Access Control Protocols for Next Generation Wireless Networks written by Xudong Wang and published by . This book was released on 2003 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self Organization in Medium Access Control for Wireless Ad Hoc and Sensor Networks written by Fan Yu and published by . This book was released on 2008 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Performance Medium Access Control Protocols for Decentralized Wireless Networks Using Local Coordination written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless networks differ from their wired counterparts in that communication between nodes takes place over a "link" using an RF, acoustic, optical, or other signal transmitted through the air or water instead of, as their name implies, a wire. This difference changes the frequency of transmission errors from extremely rare to almost constant, and introduces inter-node interference as a significant problem. Wireless networks are typically more limited than wired networks in terms of bandwidth, computational ability, power, and centralized management. Efficient handling of transmission errors and reducing interference are thus vital in maximizing network performance. This dissertation addresses two separate aspects of wireless networks with a common theme of low overhead, local coordination between nodes, and often using inferences or even informed guesses to make decisions. To address the problem of transmission errors, we study two medium access control (MAC) protocols that use minimal-overhead, local coordination schemes to allow cooperation between neighboring nodes: one with and one without a cooperation-enabled physical layer. To address the problem of interference, we study two closely related MAC protocols that use local coordination between neighboring nodes to build an interference-free transmission schedule, for (1) supporting latency-sensitive applications over long routes in mesh networks, and (2) increasing channel utilization and energy efficiency in underwater acoustic networks. Our first work focuses on mobile ad hoc networks where if any link in a route fails, multiple fruitless attempts are currently made by most of the existing MAC protocols to use the failed link before reporting failure to the routing layer and/or attempting local recovery. The high frequency of link errors between mobile nodes requires rapid recovery to provide acceptable performance. We design CIFLER, a cross-layer approach which uses enhanced channel reservation messages to allow alternate nodes to immediately elect themselves using only inferred neighbor information. This self-election avoids reliance on individual links, and uses diversity to minimize the impact frequent link errors have on delay, energy efficiency, and the functioning of upper layer protocols. We show via both analysis and simulation that CIFLER provides better performance in typical MANET scenarios. Unlike other local recovery schemes, CIFLER uses only a minor modification to IEEE 802.11 DCF, does not suffer from duplicated messages, allows neighboring nodes to almost immediately learn the information needed to assist in the recovery of existing routes, and does not require additional hardware, delays, or control messages. Our second work applies the same concept of inferred neighbor information to cooperative communications, where the signals of simultaneous transmissions by multiple nodes constructively combine in the wireless medium. Studies on the physical layer capabilities (via either information theory or numerical analysis) have shown the significant performance improvements of cooperative communications. However, these studies ignore both the overheads incurred in real implementations of the cooperative techniques at the physical layer and their interactions with higher layer protocols in a networking context. We implement a path-centric MAC protocol that uses minimal control messages to reserve a multi-hop path between source and destination nodes, and perform coordination between relay nodes. We then realistically study the performance of cooperation in networking scenarios by taking into account overheads incurred at the physical, MAC, and network layers. Simulations demonstrate that significant performance improvement can be achieved by employing cooperation. We also demonstrate the overheads which challenge the effectiveness of such schemes in real networks. Our third work deals with the issue of interference and transmission scheduling in mesh networks, where links are generally reliable if no interference is present. In current wireless networks, access to the shared wireless medium is controlled via either a TDMA- or a CSMA-based scheme. While usable in single-hop networks, these techniques are often far from optimal, and result in significant per-hop and per-packet delay and jitter, making multi-hop wireless mesh networks a particularly harsh environment for real-time, isochronous applications such as VoIP. We present a new time-based MAC protocol, FLASHR, for wireless mesh networks carrying delay-sensitive isochronous traffic. In our scheme, nodes use simple local coordination mechanisms to form adaptive transmission schedules which attain the desired quality of service. Simulations show that our scheme achieves near-optimal capacity, minimal jitter, and a weaker correlation between route length and end-to-end delay. Our final work adapts the FLASHR MAC protocol for use in underwater acoustic networks. A time-based MAC has potential advantages over FDMA and CDMA approaches in terms of hardware simplicity, energy efficiency, and delay. Unfortunately, the channel utilization of existing TDMA and CSMA acoustic MAC protocols is generally low due to the long propagation delays of acoustic signals. We argue that several ideas taken from RF protocols, including exclusive channel access, are either unnecessary in acoustic networks or must be redefined. We design UW-FLASHR, a modification to FLASHR which uses additional local control messages to create a time-based MAC protocol for acoustic networks which does not require centralized control, tight clock synchronization, or accurate propagation delay estimation. Our results show that UWFLASHR achieves higher channel utilization than the maximum utilization possible with existing time-based exclusive-access MAC protocols, particularly when the ratio of propagation delay to transmission delay is high, or data payloads are small.

Download or read book Multi channel Medium Access Protocols for Wireless Networks written by and published by . This book was released on 2006 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: As wireless technology becomes increasingly pervasive, there is a need for decentralized medium access control (MAC) protocols that satisfy user requirements at an acceptable cost of complexity and energ consumption. Hardware improvements have provided for multi-channel transceivers and leveraging this benefit necessitates further work in higher layer protocols. As devices get smaller leading to large networks formed of tiny sensor motes, the allocation of available channels without a central authority and their subsequent arbitration is a challenging task. In our work, we address this by first devising a channel allocation protocol (DCA) that ensures interference-free communication. We then propose a multi-channel MAC, C-MAC that enables energy efficient data transfer without tradeoffs in latency or throughput, and allows nodes to remain in their low-power sleep period for the maximum possible time. Apart from sensor networks, we have also analyzed the case for wireless local area networks (WLANs) that are the default providers of community and enterprise level internet connectivity. A judicious choice of the operational channel based on current network conditions can greatly improve performance in randomly deployed or hotspot areas. Our analytical estimation of interference allows each access point (AP) to independently arrive at the best channel, thus resulting in fewer re-transmissions due to neighboring traffic. For all the proposed schemes, a thorough performance evaluation has been undertaken and results reveal major improvement in performance for both WLAN and sensor networks, thus proving the viability of multi-channel communication models.