An evaluation of EpiChord in OverSim

EpiChord is a Distributed Hash Table (DHT) algorithm which supports data storage/retrieval in large scale distributed systems. It removes the typicalO(logn)-state-per-node restriction imposed by the majority of other DHT topologies by employing a reactive routing state maintenance strategy that amortizes network maintenance costs into lookup queries. Under ideal condition, EpiChord’s lookup performance can approach O(1) hops – with maintenance costs comparable to traditional multi-hop DHTs. This paper presents an implementation of EpiChord in OverSim, and validates the performance of our model against the performance reported in the original EpiChord paper. We also present some adjustments to the algorithm to remove a discrepancy and then compare our modified results with the original ones. Finally, we present additional results showing the EpiChord algorithm is stable over time and performs well for larger networks

Opportunistic Routing in Multihop Wireless Networks: Capacity, Energy Efficiency, and Security

Opportunistic routing (OR) takes advantages of the spatial diversity and broadcast nature of wireless networks to combat the time-varying links by involving multiple neighboring nodes (forwarding candidates) for each packet relay. This dissertation studies the properties, energy efficiency, capacity, throughput, protocol design and security issues about OR in multihop wireless networks. Firstly, we study geographic opportunistic routing (GOR), a variant of OR which makes use of nodes\u27 location information. We identify and prove three important properties of GOR. The first one is on prioritizing the forwarding candidates according to their geographic advancements to the destination. The second one is on choosing the forwarding candidates based on their advancements and link qualities in order to maximize the expected packet advancement (EPA) with different number of forwarding candidates. The third one is on the concavity of the maximum EPA in respect to the number of forwarding candidates. We further propose a local metric, EPA per unit energy consumption, to tradeoff the routing performance and energy efficiency for GOR. Leveraging the proved properties of GOR, we propose two efficient algorithms to select and prioritize forwarding candidates to maximize the local metric. Secondly, capacity is a fundamental issue in multihop wireless networks. We propose a framework to compute the end-to-end throughput bound or capacity of OR in single/multirate systems given OR strategies (candidate selection and prioritization). Taking into account wireless interference and unique properties of OR, we propose a new method of constructing transmission conflict graphs, and we introduce the concept of concurrent transmission sets to allow the proper formulation of the maximum end-to-end throughput problem as a maximum-flow linear programming problem subject to the transmission conflict constraints. We also propose two OR metrics: expected medium time (EMT) and expected advancement rate (EAR), and the corresponding distributed and local rate and candidate set selection schemes, the Least Medium Time OR (LMTOR) and the Multirate Geographic OR (MGOR). We further extend our framework to compute the capacity of OR in multi-radio multi-channel systems with dynamic OR strategies. We study the necessary and sufficient conditions for the schedulability of a traffic demand vector associated with a transmitter to its forwarding candidates in a concurrent transmission set. We further propose an LP approach and a heuristic algorithm to obtain an opportunistic forwarding strategy scheduling that satisfies a traffic demand vector. Our methodology can be used to calculate the end-to-end throughput bound of OR in multi-radio/channel/rate multihop wireless networks, as well as to study the OR behaviors (such as candidate selection and prioritization) under different network configurations. Thirdly, protocol design of OR in a contention-based medium access environment is an important and challenging issue. In order to avoid duplication, we should ensure only the best receiver of each packet to forward it in an efficient way. We investigate the existing candidate coordination schemes and propose a fast slotted acknowledgment (FSA) to further improve the performance of OR by using a single ACK to coordinate the forwarding candidates with the help of the channel sensing technique. Furthermore, we study the throughput of GOR in multi-rate and single-rate systems. We introduce a framework to analyze the one-hop throughput of GOR, and provide a deeper insight on the trade-off between the benefit (packet advancement, bandwidth, and transmission reliability) and cost (medium time delay) associated with the node collaboration. We propose a local metric named expected one-hop throughput (EOT) to balance the benefit and cost. Finally, packet reception ratio (PRR) has been widely used as an indicator of the link quality in multihop wireless networks. Many routing protocols including OR in wireless networks depend on the PRR information to make routing decision. Providing accurate link quality measurement (LQM) is essential to ensure the right operation of these routing protocols. However, the existing LQM mechanisms are subject to malicious attacks, thus can not guarantee to provide correct link quality information. We analyze the security vulnerabilities in the existing link quality measurement (LQM) mechanisms and propose an efficient broadcast-based secure LQM (SLQM) mechanism, which prevents the malicious attackers from reporting a higher PRR than the actual one. We analyze the security strength and the cost of the proposed mechanism

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

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

Congestion control protocols in wireless sensor networks: A survey

The performance of wireless sensor networks (WSN) is affected by the lossy communication medium, application diversity, dense deployment, limited processing power and storage capacity, frequent topology change. All these limitations provide significant and unique design challenges to data transport control in wireless sensor networks. An effective transport protocol should consider reliable message delivery, energy-efficiency, quality of service and congestion control. The latter is vital for achieving a high throughput and a long network lifetime. Despite the huge number of protocols proposed in the literature, congestion control in WSN remains challenging. A review and taxonomy of the state-of-the-art protocols from the literature up to 2013 is provided in this paper. First, depending on the control policy, the protocols are divided into resource control vs. traffic control. Traffic control protocols are either reactive or preventive (avoiding). Reactive solutions are classified following the reaction scale, while preventive solutions are split up into buffer limitation vs. interference control. Resource control protocols are classified according to the type of resource to be tuned. © 2014 IEEE

Adaptive real-time routing protocol for (M,k)-firm in industrial wireless multimedia sensor networks

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Many applications are able to obtain enriched information by employing a wireless multimedia sensor network (WMSN) in industrial environments, which consists of nodes that are capable of processing multimedia data. However, as many aspects of WMSNs still need to be refined, this remains a potential research area. An efficient application needs the ability to capture and store the latest information about an object or event, which requires real-time multimedia data to be delivered to the sink timely. Motivated to achieve this goal, we developed a new adaptive QoS routing protocol based on the (m,k)-firm model. The proposed model processes captured information by employing a multimedia stream in the (m,k)-firm format. In addition, the model includes a new adaptive real-time protocol and traffic handling scheme to transmit event information by selecting the next hop according to the flow status as well as the requirement of the (m,k)-firm model. Different from the previous approach, two level adjustment in routing protocol and traffic management are able to increase the number of successful packets within the deadline as well as path setup schemes along the previous route is able to reduce the packet loss until a new path is established. Our simulation results demonstrate that the proposed schemes are able to improve the stream dynamic success ratio and network lifetime compared to previous work by meeting the requirement of the (m,k)-firm model regardless of the amount of traffic

MQMF: Multiple Quality Measure Factors for Trust Computation and Security in MANET

Identification of the mobile ad hoc network node in a secure, reliable communication is a very important factor. It will be a node in the service of reconciliation and node behaviour leads to uncertainty. It is always challenge to manage node security and resource due to the complexity of high mobility and resource constraints. Trust based security provides light-weight security computing for individual node trust to provide reliable and quality of service. In this paper we present a multiple quality measure factors (MQMF) approach for computing node trust to improvise the quality of service. It compute four quality measure factors based on node throughput and packet drop during communication to measure the node individual trustworthiness. It prevent the network from anomalous and malicious nodes to improvise the security and throughput. The evaluation measures shows an improvisation in throughput with less packet drop and computational overload in compare to existing protocols

Non-linear echo cancellation - a Bayesian approach

Echo cancellation literature is reviewed, then a Bayesian model is introduced and it is shown how how it can be used to model and fit nonlinear channels. An algorithm for cancellation of echo over a nonlinear channel is developed and tested. It is shown that this nonlinear algorithm converges for both linear and nonlinear channels and is superior to linear echo cancellation for canceling an echo through a nonlinear echo-path channel

Final report on dissemination, regulation, standardization, exploitation & training : D6.3

In D6.1 deliverable project dissemination, exploitation and training plans, as well as standardization & regulatory approach strategy was presented. The D6.2 reported on the necessary updates of these strategies and the actions taken by the partners in line with them, as well as the obtained results. In this D6.3 deliverable, a full set of project dissemination activities, standardization & regulatory contributions as well as an operator’s “cook book” outlining steps necessary for full deployment of ON functionality and services, are presented.Deliverable D6.3 del projecte OneFITPostprint (author’s final draft