Class Of Protocols Research Articles

Estimating the Bias of CX Gates via Character Randomized Benchmarking

Recent work has demonstrated that high-threshold quantum error correction is possible for biased-noise qubits, provided one can implement a controlled-not (CX) gate that preserves the bias. Bias-preserving CX gates have been proposed for several biased-noise qubit platforms, most notably Kerr cats. However, experimentally measuring the noise bias is challenging as it requires accurately estimating certain low-probability Pauli errors in the presence of much larger state preparation and measurement (SPAM) errors. In this paper, we introduce bias randomized benchmarking (BRB) as a technique for measuring bias in quantum gates. BRB, like all RB protocols, is highly accurate and immune to SPAM errors. Our first protocol, CX-dihedral BRB, is a straightforward method to measure the bias of the entire CX-dihedral group. Our second protocol, interleaved bias randomized benchmarking (IBRB), is a generalization of interleaved RB tailored to the experimental constraints biased-noise qubits; this is a more involved procedure that directly targets the bias of the CX gate alone. Our BRB procedures occupy a middle ground between classic RB protocols that only estimate the average fidelity, and tomographic RB protocols that provide more detailed characterization of noise but require more measurements as well as experimental capabilities that are not necessarily available in biased-noise qubits.

An Enhanced Virtual Cord Protocol Based Multi-Casting Strategy for the Effective and Efficient Management of Mobile Ad Hoc Networks

To solve problems with limited resources such as power, storage, bandwidth, and connectivity, efficient and effective data management solutions are needed. It is believed that the most successful algorithms for circumventing these constraints are those that self-organise and collaborate. To make the best use of available bandwidth, mobile ad hoc networks (MANETs) employ the strategy of multi-casting. The communication cost of any network can be significantly reduced by multi-casting, and the network can save resources by transmitting only one set of data to numerous receivers at a time. In this study, we implemented multi-casting in the virtual cord protocol (VCP), which uses virtual coordinates (VC) to improve effective routing and control wireless data transmission. We have improved the classic VCP protocol by making it so that intermediate nodes can also forward or re-transmit the dataset to interested nodes. This improves data transmission from the sender to multiple receivers. Simulation results proved efficacy of our proposed enhanced virtual cord protocol-based multi-casting strategy over traditional VCP protocol and helped in reduction of number of MAC transmissions, minimization of end-to-end delay, and maximization of packet delivery ratio.

A unified description of cryptosystems: From classical to quantum protocols

The launch of quantum computing has created new challenges in the field of cryptography. Nowadays this field of research is extremely active in physics, mathematics and computer science. In this paper we present an overview of the most common classical and quantum protocols. The former are usually defined through a 5-uple given by a plaintext space, a ciphertext space, an encryption and decryption space, an encryption function and a decryption function. Here, we show how to unify quantum and classical protocols by using the same formalism of the 5-uple mentioned above.

RDMA-Enabled Concurrency Control Protocols for Transactions in the Cloud Era

Online transaction processing (OLTP) is widely used on modern cloud infrastructures to complete important businesses such as payments and stock exchanges. Remote Direct Memory Access (RDMA) is a technology that enables ultra-low inter-server memory access latency - which is critical for implementing high-performance concurrency control protocols in distributed OLTP. In this article, we develop RCC, the first unified and comprehensive RDMA-enabled distributed transaction processing framework containing six serializable concurrency control protocols—not only the classical protocols <inline-formula><tex-math notation="LaTeX">${{\sf NOWAIT}}$</tex-math></inline-formula> , <inline-formula><tex-math notation="LaTeX">${{\sf WAITDIE}}$</tex-math></inline-formula> , <inline-formula><tex-math notation="LaTeX">${{\sf OCC}}$</tex-math></inline-formula> , but also more advanced <inline-formula><tex-math notation="LaTeX">${{\sf MVCC}}$</tex-math></inline-formula> , <inline-formula><tex-math notation="LaTeX">${{\sf SUNDIAL}}$</tex-math></inline-formula> , and <inline-formula><tex-math notation="LaTeX">${{\sf CALVIN}}$</tex-math></inline-formula> — the deterministic protocol. Our goal is to unbiasedly compare protocols on OLTP workloads in a common execution environment with the concurrency control protocol being the only changeable component. From RCC, we obtained new insights on building RDMA-based protocols. We analyzed stage-wise latency breakdown to develop more efficient hybrid implementations. Moreover, RCC can enumerate all stage-wise hybrid designs under a given workload characteristic. Our results show that throughput-wise hybrid designs are better than RPC or one-sided counterparts by 32.2% and up to 67%; three hybrid designs are better than their pure counterparts by up to 17.8%. RCC can provide performance insights and be used as the common open-sourced infrastructure for fast prototyping new implementations.

An exploration of integration of IoT and 5G networks and a fuzzy approach for clustering to enhance the lifetime of such networks

Medium access control protocols play an important role for allocating the medium to the smart devices connected on the networks. These networks include IoT and sensor networks, IoT and 5G networks, IoT and optical networks using 5G communication etc. MAC protocols ensure the efficient and fair communication through these networks from devices to base station. Wireless sensor networks are considered as the back bone for the internet controlled applications. These networks set up link between virtual and real world. The selection of the suitable MAC protocol can help in improving the network life time so the data collected by the nodes is delivered to its destination. So this paper explores the various MAC protocols available for IoT and 5G applications and .The parameters of study for these MAC protocols used for the real time applications includes residual energy, throughput, packet delivery ratio, latency and network lifetime. The paper also explores the usages of machine learning and AI used in MAC protocols for these high speed IoT networks. The work addresses the improvement of network lifetime and residual energy by applying Fuzzy approach for the selection of cluster head . The energy consumption increases if the clusters are not balanced in terms of the nodes so we have used the grid formation of the clusters. We used the Fuzzy Logic Inference system (FIS) in the cluster formation technique. The probabilistic method for election of cluster head does not consider the parameters such as residual energy, node position and base station distance. This result in the improper selection of the cluster head .The use of multiple parameters in the FIS improves the network lifetime and residual energy as compared to the classical LEACH protocol. Fuzzy logic approach solves the uncertainties occurring in the system especially when it is handling the larger amount of data. The fuzzy approach shows the prolonged network lifetime in terms of first node die and the Last node Die. We have also used the statistical regression approach to calculate the residual energy and network life time in terms of alive nodes. Finally this chapter ends with the discussion of challenges and future scope of the MAC protocols used for the real time applications. The work is important as it gives opportunity for the research areas in high speed IoT and 5G networks for using AI and ML intelligent to develop QoS MAC protocols.

TCP-Puerto-Londero: A New Approach for End-to-End Queue Length Control

This paper presents a new TCP protocol called TCPPuerto-Londero, which makes dynamic tuning in the congestion window (cwnd) by means of adaptive control theory aiming to keep stable and small the queue length in the bottleneck link located on the path from source to destination. This adaptive control loop has the relative delay in the forward path measured as an input and the cwnd value as an output. Thus, unlike classic TCP protocols, TCP-Puerto-Londero does not use Round Trip Time (RTT) information. Also, unlike classic Active Queue Management (AQM) strategies and Explicit Congestion Notification (ECN) based protocols, TCP-Puerto-Londero employs end-to-end queue management without the need for ECN resources. Moreover, TCP-Puerto-Londero also aims to attend to the new challenges of the Industrial Internet of Things (IIoT). Its performance has been tested in a Dumbbell network topology shared by TCP and UDP-like Networked Control Systems (NCS) flows. Therefore, TCP-Puerto-Londero performance has been compared with ECN-based protocols like DCTCP, E-DCTCP, TCP-Jersey, and ENCN. Furthermore, this paper employs an approach for modeling, analysis, simulation, and verification of the communication network and NCS employing UPPAAL simulation software tool, where all network constituents (transmitters, channels, routers, receivers, controllers, and plants) were modeled employing timed automata, simplifying a formal verification of the complete studied system. Simulations and statistical verification indicate that even though utilizing fewer resources (as it does not require the AQM/ECN information) TCP-Puerto-Londero overcomes TCP-Jersey, DCTCP, and EDCTCP with regard to throughput and fairness for TCP flows. Also, TCP-Puerto-Londero flows are capable to keep the queue length more stable and smaller than other protocols that were compared, and consequently, it reduces the impact in NCS-UDPlike flows sharing the same network, whose performance was measured employing the Integral Time Absolute Error (ITAE), which is a desirable feature for Industrial IoT.

Classical Recombinant DNA Cloning.

Traditional molecular cloning involves a series of linked experimental steps performed with the overall goal of isolating ("cloning") a specific DNA sequence-often a gene. The main purpose of cloning is to study either that DNA sequence or the RNA or protein product it encodes. Building on key enzymatic discoveries in the late 1960s, gene cloning was pioneered in the early 1970s. Since then, DNA cloning and manipulation have been used in every area of biological and biomedical research, from molecular genetics, structural biology, and developmental biology to neurobiology, ancient DNA studies, and immunology. It is a versatile technique that can be applied to a variety of starting DNA types and lengths, including cDNAs, genes, gene fragments, chromosomal regions, or shorter fragments such as PCR products and functional control regions such as enhancers or promoters. The starting DNA can originate from any cell, tissue, or organism. In this chapter we will cover traditional ("classic") molecular cloning strategy. This comprises six linked stages in which (1) PCR is used to amplify a DNA region of interest that is then (2) digested with restriction enzymes, alongside a selected vector, to produce complementary ends crucial for the two molecules to be (3) ligated by an ATP-dependent DNA ligase, creating a recombinant DNA molecule. The recombinant DNA is then (4) introduced into competent bacterial cells by transformation and (5) grown on a selective agar media, followed by (6) colony-PCR for screening purposes. We provide a worked example to demonstrate the cloning of an average-size gene (in this case the 2kb DNA ligase A gene) from E. coli into a common plasmid expression vector. We have included six color figures and two tables to depict the key stages of a classical molecular cloning protocol. If you are cloning a segment of DNA or a gene, remember that each DNA cloning experiment is unique in terms of sequence, length, and experimental purpose. However, the principles of traditional cloning covered in this chapter are the same for any DNA sequence; we have included a detailed notes section, so you should easily be able to transfer them to your own work. Some of the following chapters in this volume will cover other, more recently developed, cloning protocols.

USE OF THE 1-WIRE PROTOCOL IN SMART HOME COMPUTER SYSTEMS

The article examines the computer systems used in the “Smart House”. A comparative analysis of these computer systems was carried out. It was emphasized that such systems have a number of advantages that have a positive impact on human life and safety. The use of temperature measuring devices is widely used in computer systems to monitor Smart Home conditions. The need to install a large number of sensors leads to an increase in the complexity of such computer systems. Protocols for connecting sensors to a microcontroller play an important role in system development. The analysis of the latest publications and studies provides information on the widespread use of the 1-Wire protocol in various fields to solve practical problems and the need for further improvement of systems using this protocol. Two simulation models of “Smart House” computer systems for determining indoor temperature based on the classic connection protocol and using the 1-Wire protocol are presented. The simulation model based on the standard protocol uses: an Arduino Uno board based on an Atmega328p microcontroller, LM35 temperature sensors and a 74HC4051D multiplexer. In the simulation model using the 1-Wire protocol, the following are used: Arduino Uno board and DS18B20 digital temperature sensors. Information is given on the operation of the 1-Wire protocol, which is widely used to connect a large number of sensors with such an interface, namely, there is a theoretical possibility of addressing an unlimited number of similar devices on a single-wire line. In the simulation model of the system with the used 1-Wire protocol, the number of sensors connected to one output is increased to 12 in order to analyze and demonstrate the capabilities of the system. According to the simulation results, the following parameters are presented: the number of possible connections, the complexity of the design, the use of compact software code, the frequency of the clock signal, and the cost of the Smart Home computer systems. The results of the analysis of the considered simulation models of computer systems are presented in the conclusions. Advantages and disadvantages of systems with 1-Wire protocol are given.

Convulsive behaviors of spontaneous recurrent seizures in a mouse model of extended hippocampal kindling.

Growing studies indicate that vigilance states and circadian rhythms can influence seizure occurrence in patients with epilepsy and rodent models of epilepsy. Electrical kindling, referred to brief, repeated stimulations of a limbic structure, is a commonly used model of temporal lobe epilepsy. Kindling via the classic protocol lasting a few weeks does not generally induce spontaneous recurrent seizures (SRS), but extended kindling that applies over the course of a few months has shown to induce SRS in several animal species. Kindling-induced SRS in monkeys and cats were observed mainly during resting wakefulness or sleep, but the behavioral activities associated with SRS in rodent models of extended kindling remain unknown. We aimed to add information in this area using a mouse model of extended hippocampal kindling. Middle-aged C57 black mice experienced ≥80 hippocampal stimulations (delivered twice daily) and then underwent continuous 24 h electroencephalography (EEG)-video monitoring for SRS detection. SRS were recognized by EEG discharges and associated motor seizures. The five stages of the modified Racine scale for mice were used to score motor seizure severities. Seizure-preceding behaviors were assessed in a 3 min period prior to seizure onset and categorized as active and inactive. Three main observations emerged from the present analysis. (1) SRS were found to predominantly manifest as generalized (stage 3-5) motor seizures in association with tail erection or Straub tail. (2) SRS occurrences were not significantly altered by the light on/off cycle. (3) Generalized (stage 3-5) motor seizures were mainly preceded by inactive behaviors such as immobility, standing still, or apparent sleep without evident volitional movement. Considering deeper subcortical structures implicated in genesis of tail erection in other seizure models, we postulate that genesis of generalized motor seizures in extended kindled mice may involve deeper subcortical structures. Our present data together with previous findings from post-status epilepticus models support the notion that ambient cage behaviors are strong influencing factors of SRS occurrence in rodent models of temporal lobe epilepsy.

Quantum-enhanced Doppler lidar

We propose a quantum-enhanced lidar system to estimate a target’s radial velocity, which employs squeezed and frequency-entangled signal and idler beams. We compare its performance against a classical protocol using a coherent state with the same pulse duration and energy, showing that quantum resources provide a precision enhancement in the estimation of the velocity of the object. We identify three distinct parameter regimes characterized by the amount of squeezing and frequency entanglement. In two of them, a quantum advantage exceeding the standard quantum limit is achieved assuming no photon losses. Additionally, we show that an optimal measurement to attain these results in the lossless case is frequency-resolved photon counting. Finally, we consider the effect of photon losses for the high-squeezing regime, which leads to a constant factor quantum advantage higher than 3 dB in the variance of the estimator, given a roundtrip lidar-to-target-to-lidar transmissivity larger than 50%.

Convergence condition of simulated quantum annealing for closed and open systems

Simulated quantum annealing is a generic classical protocol to simulate some aspects of quantum annealing and is sometimes regarded as a classical alternative to quantum annealing in finding the ground state of a classical Ising model. We derive a generic condition for simulated quantum annealing to converge to thermal equilibrium at a given, typically low, temperature. Both closed and open systems are treated. We rewrite the classical master equation for simulated quantum annealing into an imaginary-time Schr\"odinger equation, to which we apply the imaginary-time variant of asymptotic adiabatic condition to deduce the convergence condition. The result agrees qualitatively with a rigorous convergence condition of simulated quantum annealing for closed systems, which was derived from the theory of inhomogeneous Markov process. Also observed is qualitative agreement with a rigorous convergence condition of quantum annealing for closed systems under the real-time Schr\"odinger dynamics. This coincidence of convergence conditions for classical stochastic processes for simulated quantum annealing and the real-time quantum dynamics for quantum annealing is highly non-trivial and calls for further scrutiny.

986. Pseudomonas Prosthetic Joint Infections: Is there a role for monotherapy?

Abstract Background Pseudomonas species are a less common but devastating pathogen family in prosthetic joint infections (PJI). Despite advancements in management, Pseudomonas PJI remains particularly difficult to treat due to fewer antibiotic options and robust biofilm formation. The purpose of this study was to better evaluate outcomes after Pseudomonas PJI treatment. Methods All hip or knee PJIs, at a single institution, with positive Pseudomonas culture were analyzed. 51 patients (29 hips and 22 knees) meeting inclusion criteria were identified. The primary outcome of interest was infection clearance at 1-year after surgical treatment, defined as reassuring aspirate without ongoing antibiotic treatment or death within one year post-operatively. Monomicrobial and polymicrobial infections were evaluated separately. Results Among monomicrobial PJIs, ten (50.0%) patients were clear of infection at one year post-operatively. Patients treated with 2-stage exchange (n=11) had a 1-year clearance rate of 54.5% compared to 60.0% with DAIR (n=5) and 25.0% with resection or amputation (n=4). Two of six patients treated with fluoroquinolone monotherapy met 1-year infection clearance, despite fluoroquinolone sensitivity, compared to four of five patients meeting 1-year clearance when treated with combined intravenous and oral therapy for at least 6 weeks. Resistance to anti-pseudomonal agents was infrequent (20%, n=4/20), and three of ten mono- and polymicrobial PJI patients with recurrent Pseudomonas PJI developed resistance to anti-pseudomonal therapy. Polymicrobial infections were the most common presentation (54.9%) of Pseudomonas positive PJI with a mortality rate of 46.4% (n=13/28) at a median follow-up of 4.2 years [IQR: 3.4-5.7]. Conclusion Despite surgical and antibiotic treatment regimens consistent with traditional treatment algorithms, our data portrays poor clearance rate of Pseudomonas PJI with relatively poor outcomes in patients treated with oral or intravenous monotherapy. Pseudomonas infections are difficult to eradicate and likely require deviations from classical therapeutic protocols to improve treatment success. Disclosures William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson &amp; Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith &amp; Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

Availability of Metribuzin-Loaded Polymeric Nanoparticles in Different Soil Systems: An Important Study on the Development of Safe Nanoherbicides.

Nanoformulations have been used to improve the delivery of fertilizers, pesticides, and growth regulators, with a focus on more sustainable agriculture. Nanoherbicide research has focused on efficiency gains through targeted delivery and environmental risk reduction. However, research on the behavior and safety of the application of these formulations in cropping systems is still limited. Organic matter contained in cropping systems can change the dynamics of herbicide−soil interactions in the presence of nanoformulations. The aim of this study was to use classical protocols from regulatory studies to understand the retention and mobility dynamics of a metribuzin nanoformulation, compared to a conventional formulation. We used different soil systems and soil with added fresh organic material. The batch method was used for sorption−desorption studies and soil thin layer chromatography for mobility studies, both by radiometric techniques. Sorption parameters for both formulations showed that retention is a reversible process in all soil systems (H~1.0). In deep soil with added fresh organic material, nanoformulation was more sorbed (14.61 ± 1.41%) than commercial formulation (9.72 ± 1.81%) (p < 0.05). However, even with the presence of straw as a physical barrier, metribuzin in nano and conventional formulations was mobile in the soil, indicating that the straw can act as a barrier to reduce herbicide mobility but is not impeditive to herbicide availability in the soil. Our results suggest that environmental safety depends on organic material maintenance in the soil system. The availability can be essential for weed control, associated with nanoformulation efficiency, in relation to the conventional formulation.

Lyophilized amniotic membrane for corneal ulcer and post operative cross‐linking

AbstractPatients with progressive keratoconus, especially in the early part of life, may benefit from crosslinking to accelerate the polymerization of corneal collagen, thus increasing the biomechanical strength of the cornea. The reference crosslinking protocol, recognized as the most effective in stabilizing the disease, corresponds to a classic crosslinking protocol with de‐epithelialization (epi off). This technique is pro‐inflammatory in patients who often have associated allergic keratoconjunctivitis. It is also painful postoperatively despite the systematic application of a dressing lens since it requires corneal de‐epithelialisation. The allergic background can lead to delays in healing with postoperative infections. Amniotic membranes have already been used in post refractive surgery. Their application in post‐crosslinking protocol epi off, directly on the patient's cornea without suture under a therapeutic contact lens, would reduce the intensity of pain after the procedure, complications such as infectious keratitis, sterile infiltrates, superficial or deep haze, aseptic corneal necrosis (thinning and fibrosis, perforation described), endothelial damage due to probable excessive free radical toxicity (reversible corneal decompensation or requiring a corneal graft), delayed epithelial healing (association of dry syndrome or blepharitis) and viral reactivation (Herpes Simplex virus or HSV). The amniotic membrane by its anti‐angiogenic, healing, anti‐inflammatory and anti‐infectious properties seems to have a decrease in post‐operative pain and an acceleration of corneal epithelial healing as in superficial corneal ulcers.

Transmission estimation at the quantum Cramér-Rao bound with macroscopic quantum light

The field of quantum metrology seeks to apply quantum techniques and/or resources to classical sensing approaches with the goal of enhancing the precision in the estimation of a parameter beyond what can be achieved with classical resources. Theoretically, the fundamental minimum uncertainty in the estimation of a parameter for a given probing state is bounded by the quantum Cramér-Rao bound. From a practical perspective, it is necessary to find physical measurements that can saturate this fundamental limit and to show experimentally that it is possible to perform measurements with the required precision to do so. Here we perform experiments that saturate the quantum Cramér-Rao bound for transmission estimation over a wide range of transmissions when probing the system under study with a continuous wave bright two-mode squeezed state. To properly take into account the imperfections in the generation of the quantum state, we extend our previous theoretical results to incorporate the measured properties of the generated quantum state. For our largest transmission level of 84%, we show a 62% reduction over the optimal classical protocol in the variance in transmission estimation when probing with a bright two-mode squeezed state with −8 dB of intensity-difference squeezing. Given that transmission estimation is an integral part of many sensing protocols, such as plasmonic sensing, spectroscopy, calibration of the quantum efficiency of detectors, etc., the results presented promise to have a significant impact on a number of applications in various fields of research.

Trends in point-of-care ultrasound protocols in the emergency department and intensive care unit: a review

Abstract Together with the development of the focused assessment with sonography for trauma protocol for ultrasound in trauma patients, point-of-care ultrasound is widely used in the field of emergency and critical care medicine. Researchers have established several classic operating protocols for different diseases, such as acute respiratory failure, shock, and cardiac arrest, in the emergency department and intensive care unit. With further development in the portability and popularity of ultrasonic equipment, it is expected to be used as a new type of technology for physical examination, including inspection, palpation, percussion, auscultation, and insonation, which will improve the clinical medicine practice in the future.

Maximum Concurrent Flow Solutions for Improved Routing in IoT Future Networks.

Due to the advent of IoT and the increasing interest of billions of Internet users towards video contents, a huge multimedia flows has been generated, and as a consequence, a massive load is applied on the underlying core network. This change can affect the network stability and lead to potential performance degradation (such as congestion and delays). This is because multimedia flows are hungry in bandwidth, and also the classical routing protocols currently used in IoT core network (like OSPF) are not adapted yet to support the heavy and the large scale of multimedia traffics with a good quality of service (QoS). In this paper, we introduce the multicommodity-based routing by proposing two contributions, Maximum Concurrent Flow Protocol (MCFPr) and Cache-based Maximum Concurrent Flow (C-MCF). They are conceived based on the Maximum Concurrent Flow approach in order to optimize the routing of multimedia data in the backbone of IoT networks. Both contributions are studied and compared with the state-of-art approaches under different scenarios showing good results, especially in the number of data packets sent (improvement by 50%), and in the transmission time (50% faster compared to the majority), which makes them promising solutions for a rapid and efficient routing in IoT core networks.

ZAMA: A ZKP-Based Anonymous Mutual Authentication Scheme for the IoV

Internet of Vehicles (IoV) is a typical application of mobile Internet of Things (IoT), which aims to improve road conditions and enhance the driving experience. However, the issue of identity leakage has drawn a major privacy concern during the vehicle’s authentication. It is impractical to apply traditional anonymous authentication methods directly to the IoV system due to their complex computation. To enhance the user’s privacy and the service’s efficiency, we propose a novel efficient anonymous authentication approach for the IoV based on the zero-knowledge proof (ZKP) and elliptic curve cryptography (ECC). We achieve the user’s strong anonymity and authenticity based on the Fujisaki–Okamoto Commitment algorithm. In addition, the third trusted authority can effectively trace users by tracking users’ verification keys. It holds the user’s traceability when a violation occurs. Meanwhile, we design a fast reconnection procedure based on the security context from the last access, which can reduce the computation overhead effectively. Through the security analysis, it proves that our scheme provides the anonymity, mutual authenticity, unlinkability, traceability, forward security, and replay-attack resistance. The experimental results indicate that our scheme has a better performance compared with the classic protocols in the IoV.

Strategies to increase connectivity and performance of VANETs: Analysis of route lifetime and routing protocol proposal

AbstractVehicular ad hoc networks aim to provide communication among vehicles, providing safety and entertainment to passengers. The performance of these networks is entirely dependent on the existence of routes and the time they remain established (the route lifetime). Several factors can influence route lifetime and network connectivity, for instance: speed, density, direction of movement, and radio transmission range. The investigation of route lifetime and what are the critical physical factors, can assist in building more appropriate protocols and applications, developing efficient mobile communication infrastructures. Therefore, this article proposes strategies to increase the performance of V2V vehicular networks, through the analysis of which factors most influence performance and the development of a new routing protocol, which based on these factors, is able to select the best routes. The simulations prove that the route lifetime increases in denser networks and when vehicle movement occurs in the same direction. Meanwhile, the route lifetime does not undergo significant changes depending on the speed of vehicles. Based on these results, the Improved Connectivity Ad Hoc On‐Demand Multipath Distance Vector (IC_AOMDV) protocol was developed which, without the use of any fixed infrastructure (eg, GPS), surpassed the classic AOMDV and AODV protocols in all metrics tested.

Energy-Efficient Guiding-Network-Based Routing for Underwater Wireless Sensor Networks

With the increasing underwater applications, underwater wireless sensor networks (UWSNs) have become a research hotspot. Routing protocols used to keep network connectivity and reliable transmission are essential in UWSNs. Due to the specific limitations in UWSNs, such as serious ocean interference, high propagation latency, and dynamic network topology, it is challenging to balance multiple performances, such as real timeness and energy efficiency in a routing protocol. To this end, this article proposes a localization-free routing scheme, termed energy-efficient guiding-network-based routing (EEGNBR) protocol, to provide a time saving and reliable routing for UWSNs, which is a good choice for applications characterized by intermittent connectivity. For reducing the network delay, EEGNBR cites the advantageous distance-vector mechanism and establishes a guiding network to provide underwater sensor nodes with the shortest route (minimum hop counts) toward the sinks. Moreover, EEGNBR innovatively replaces the waiting mechanism used in traditional opportunistic routing with a novel data forwarding mechanism named concurrent working mechanism, which could greatly reduce the forwarding delay while guaranteeing reliable routing. In order to ensure routing reliability as well as avoid duplicate transmission, the forwarding protection mechanism is adopted to save energy consumption and extend the service life of the network. Simulation results show that EEGNBR performs significantly better than some classical related protocols in terms of network delay while maintaining comparable or even better energy consumption and packet delivery ratio.