1,162 research outputs found

    Improve Energy Efficiency In Cooperative Medium Access Control Protocol For Wireless Networks

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    Cooperative communication has drawn a substantial attention in recent years due to the efficient and optimal utilization of constraint resources in dynamic wireless networks at a reduced infrastructural deployment and cost. In the medium access control (MAC) layer perspective, two major problems are associated with cooperative networks. The ability of cooperative MAC (CMAC) protocols to achieve multi-objective target orientation limit their adaptation to the future generation of wireless networks, since most of the existing protocols focus only on a single target objective. Besides, the sustainability of energy-constrained wireless networks due to limited energy supply capacity hinders their performance to ensure stable and reliable communication. These aforementioned problems limit the adaptation of the existing protocols to fit into the future generation of wireless networks. To adequately address these problems, two distinct CMAC protocols are proposed in this thesis to cater for the unpredictable and dynamic nature of the wireless network. Firstly, a new network lifetime-aware CMAC protocol named LEA-CMAC is proposed for energy-constrained wireless ad-hoc networks. An optimization problem is formulated with an objective of extending the lifetime of the network. The solution to this non-linear problem is provided in terms of optimal transmit power at the source and relay terminals in symmetric and asymmetric transmit power policies. The solution provided by this protocol is limited in terms of energy efficiency and network lifetime since the network totally rely on the helper nodes limited-powered batteries for their transmissions. Secondly, a novel CMAC protocol with radio frequency (RF) energy harvesting (EH) capability named EH-CMAC is proposed in a reactive relaying energy-constrained wireless ad-hoc networks to address the limitation in the earlier proposed LEA-CMAC protocol. The protocol possesses the ability to ensure a sustainable and reliable wireless connectivity in a dynamic wireless environment through the selection of an appropriate transmission mode that best suits the instantaneous network requirement. The protocol comprises of two distinct energy-efficient techniques namely, the outage probability quality-of-service (QoS) requirement and the transmit power optimization techniques which are applied in both traditional and EH relaying schemes. These techniques are selected and adapted based on the instantaneous network information and target objectives. In addition, a distributed and adaptive relay selection backoff process is proposed in each case to satisfy the available network information and achieve a multi-objective target oriented protocol. Through extensive simulation and comparison with existing CMAC protocols, the results show that LEA-CMAC extend the network lifetime by 85.67% over an existing CMAC protocol, while EH-CMAC extends the network lifetime by 90.99% over a traditional CMAC protocol. Thus, both protocols achieve a multi-objective target orientation under general circumstances

    A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

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    In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

    Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey

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    Wireless sensor networks (WSNs) consist of autonomous and resource-limited devices. The devices cooperate to monitor one or more physical phenomena within an area of interest. WSNs operate as stochastic systems because of randomness in the monitored environments. For long service time and low maintenance cost, WSNs require adaptive and robust methods to address data exchange, topology formulation, resource and power optimization, sensing coverage and object detection, and security challenges. In these problems, sensor nodes are to make optimized decisions from a set of accessible strategies to achieve design goals. This survey reviews numerous applications of the Markov decision process (MDP) framework, a powerful decision-making tool to develop adaptive algorithms and protocols for WSNs. Furthermore, various solution methods are discussed and compared to serve as a guide for using MDPs in WSNs

    Robotic Wireless Sensor Networks

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    In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

    Medium access control protocol design for wireless communications and networks review

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    Medium access control (MAC) protocol design plays a crucial role to increase the performance of wireless communications and networks. The channel access mechanism is provided by MAC layer to share the medium by multiple stations. Different types of wireless networks have different design requirements such as throughput, delay, power consumption, fairness, reliability, and network density, therefore, MAC protocol for these networks must satisfy their requirements. In this work, we proposed two multiplexing methods for modern wireless networks: Massive multiple-input-multiple-output (MIMO) and power domain non-orthogonal multiple access (PD-NOMA). The first research method namely Massive MIMO uses a massive number of antenna elements to improve both spectral efficiency and energy efficiency. On the other hand, the second research method (PD-NOMA) allows multiple non-orthogonal signals to share the same orthogonal resources by allocating different power level for each station. PD-NOMA has a better spectral efficiency over the orthogonal multiple access methods. A review of previous works regarding the MAC design for different wireless networks is classified based on different categories. The main contribution of this research work is to show the importance of the MAC design with added optimal functionalities to improve the spectral and energy efficiencies of the wireless networks

    D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking

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    Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the various Joint Research Activities (JRA) in WP1.3 and the results that were developed up to the second year of the project. For each activity there is a description, an illustration of the adherence to and relevance with the identified fundamental open issues, a short presentation of the main results, and a roadmap for the future joint research. In the Annex, for each JRA, the main technical details on specific scientific activities are described in detail.Peer ReviewedPostprint (published version
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