Author: Wiwat RuengmeePublisher:
ISBN:
Category :
Languages : en
Pages : 88
Book Description
Medium Access Control (MAC) Protocol for Reconfigurable Wireless Networks
Author: Wiwat RuengmeeReconfigurable Medium Access Control Protocols for Wireless Networks
Author: MAC Protocol Design in Full-Duplex Enabled Wireless Networks
Author: Liqun FuPublisher: Springer Nature
ISBN: 3031572963
Category :
Languages : en
Pages : 158
Book Description
MAC Scheme for Reconfigurable Wireless Networks
Author: Rakesh K. ShahReconfigurable Medium Access Control Solutions for Resource Constrained Wireless Networks
Author: Noemí Arbós LinioPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
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.
Analytical Modeling of Medium Access Control Protocols in Wireless Networks
Author: Marcelo Menezes CarvalhoPublisher:
ISBN:
Category :
Languages : en
Pages : 468
Book Description
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.
Automated Design of Optimal Medium Access Control Protocols for Wireless Networking
Author: Jian ZhenPublisher:
ISBN: 9781321568905
Category :
Languages : en
Pages : 169
Book Description
We present a framework for the automated design of optimal Medium Access Control (MAC) protocols for wireless networks.
Mobility based routing overhead management in reconfigurable wireless ad hoc networks
Author: Wilfred Githuka GikaruPublisher: Cuvillier Verlag
ISBN: 3865372783
Category : Mobile computing
Languages : en
Pages : 145
Book Description
Learning-Based Reconfigurable Multiple Access Schemes for Virtualized MTC Networks
Author: Tho Le-NgocPublisher: Springer Nature
ISBN: 3030603822
Category : Computers
Languages : en
Pages : 191
Book Description
This book assists readers with understanding the key aspects, problems and solutions related to the design of proper Multiple Access Schemes for MTC (Machine-Type Communications) and IoT applications in 5G-and-beyond wireless networks. An overview of MTC applications and their traffic features are also provided. In addition, it presents a comprehensive review of MTC access schemes including orthogonal multiple access schemes (OMA), non-orthogonal multiple access schemes (NOMA), massive MIMO-based schemes and fast uplink grant approaches. It also proposes efficient and reconfigurable access schemes deploying machine learning and optimization techniques to address the main requirements of MTC networks. This book discusses potential research directions to further enhance the performance of MTC access schemes. Machine-type communications are expected to account for the dominant share of the traffic in future wireless networks. While in traditional wireless networks, designed for human-type communications, the focus is on support of large packet sizes in downlink, machine-type communication systems deal with heavy uplink traffic. This is due to the nature of the tasks performed by machine-type communication devices, which is mainly reporting measured data or a detected event. Furthermore, in these networks, using the virtualization framework, the network infrastructure can be shared between different applications for which providing isolation is of high importance. To support these unique characteristics of machine-type communications, proper access schemes need to be developed, which is the focus of this book. This book benefits advanced-level students studying computer science and electrical engineering as a secondary textbook and researchers working in this field. Engineers and practitioners interested in the challenges and practical solutions of integrating MTC in the cloud radio access network of 5G-and-beyond cellular systems will want to purchase this book as well.
High Performance Medium Access Control Protocols for Decentralized Wireless Networks Using Local Coordination
Author: Publisher:
ISBN: 9781109249194
Category : Wireless communication systems
Languages : en
Pages :
Book Description
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.