Delay Tolerant Networks Research Articles

Survey on securing wireless networks through a blockchain-based framework

In the contemporary era, blockchain technology has brought about a significant transformation in the realm of digital currency through innovations like Bitcoin. A blockchain serves as a decentralized ledger, ensuring an immutable record of transactions across a network. Recent observations indicate the pivotal role of blockchain technology not only in the financial sector but also in networking. This study considers blockchain as the essential link in establishing a genuinely decentralized, trustless, and secure environment for network nodes. The objective is to provide a systematic and comprehensive overview of futuristic endeavours in this domain. The exploration begins with an examination of the fundamental operational concepts of blockchains and how these systems achieve decentralization, security, and suitability. The focus then shifts towards addressing open research challenges within blockchain technologies, particularly in securing diverse communication networks such as Distributed Computing, Vehicular Ad-hoc Networks, Opportunistic Networks, and Delay Tolerant Networks. Simulation results underscore the superior security performance of blockchain, especially under conditions of attack.

New Trust Based Smart Data Forwarding Mechanism in Vehicular Delay Tolerant Network

Vehicular Delay Tolerant Network (VDTN) is the growing field with a considerable possibility to handle future wireless application’s requirements. Using vehicles for the data communication purpose can be contemplated as a substitute for the wired and wireless systems. This paper proposes a trust-based data forwarding mechanism for Vehicular Delay Tolerant Network (VDTN). Data forwarding in VDTN requires every vehicular or stationary node to participate in data forwarding. But some time malicious nodes show non-cooperative behaviour in data forwarding. Therefore, malicious nodes must be identified specifically to accelerate the data forwarding. A threshold based social skeleton membership process along with new trust-based data forwarding mechanism is proposed in this paper. We reveal that the social skeleton members perform better in data forwarding in terms of data delivery ratio, data delay and data overhead. Simulation results demonstrate that the trust-based data forwarding improves the data delivery ratio with trust-based data forwarding approach. After simulation a comparative analysis of two different scenarios is presented with epidemic routing, prophet routing and spray and wait routing.

FloatingBlue: A Delay Tolerant Networks-Enabled Internet of Things Architecture for Remote Areas Combining Data Mules and Low Power Communications.

Monitoring vast and remote areas like forests using Wireless Sensor Networks (WSNs) presents significant challenges, such as limited energy resources and signal attenuation over long distances due to natural obstacles. Traditional solutions often require extensive infrastructure, which is impractical in such environments. To address these limitations, we introduce the "FloatingBlue" architecture. This architecture, known for its superior energy efficiency, combines Bluetooth Low Energy (BLE) technology with Delay Tolerant Networks (DTN) and data mules. It leverages BLE's low power consumption for energy-efficient sensor broadcasts while utilizing DTN-enabled data mules to collect data from dispersed sensors without constant network connectivity. Deployed in a remote agricultural area in the Amazon region, "FloatingBlue" demonstrated significant improvements in energy efficiency and communication range, with a high Packet Delivery Ratio (PDR). The developed BLE beacon sensor achieved state-of-the-art energy consumption levels, using only 2.25 µJ in sleep mode and 11.8 µJ in transmission mode. Our results highlight "FloatingBlue" as a robust, low-power solution for remote monitoring in challenging environments, offering an energy-efficient and scalable alternative to traditional WSN approaches.

Study to integrate Delay-Tolerant Network protocols in IoT LEO constellations for flood prevention

In the era of the Internet of Things (IoT) the development of Direct-to-Satellite IoT (DtS-IoT) applications are becoming increasingly relevant. These applications are based on enabling IoT devices to communicate directly with satellites. In this scenario, LEO satellites can provide global IoT service coverage, becoming essential to connect devices in remote areas. As an example, the deployment of NarrowBand-IoT (NB-IoT) service is being actively investigated with the apparition of Non-Terrestrial Network (NTN) and DtS-IoT concepts. Although some initiatives propose seamless and ubiquitous service, these features may not be required for IoT applications. This relaxes the requirements in the satellite constellation architecture, enabling it to be more sparse. The connection between sensors, satellites and ground segment becomes intermittent and discontinuous in these non-dense architectures. Delay/Disruptive-tolerant protocols are essential to coexist with this network characteristics. Unfortunately, traditional IoT protocols have not been designed with this delay-tolerant feature. This work tackles this challenge by integrating Delay-Tolerant Network protocols with NB-IoT architecture. Specifically, the integration is based on interconnecting the Bundle Protocol and IP traffic through a novel interface. This development has been divided in three phases: (1) The definition of an architecture and protocol stack to tackle NTN IoT scenarios with discontinuities, (2) the analysis from simulated data of the resulting protocol stack in a realistic scenario based on flooding prevention, and (3) the implementation and validation of it in a laboratory testbed. The proposed case study uses a Direct-to-Satellite IoT architecture to create an early warning flooding detection system. The simulation results provide insights of the achieved performance with these architectures when servicing hundreds of sensing nodes.

A blockchain transaction mechanism in the delay tolerant network

Current blockchain systems have high requirements on network connection and data transmission rate, for example, nodes have to receive the latest blocks in time to update the blockchain, nodes have to immediately broadcast the generated block to other nodes for consensus, which restricts the blockchain to run only on real-time connection networks, but the existence of delay tolerant networks poses a great challenge to the deployment of blockchain systems. To address this challenge, a novel blockchain transaction mechanism is proposed. First, the block structure is modified by adding a flag, and on this basis, the definition of the extrachain is proposed. Secondly, based on the blockchain transaction process, transaction verification and consensus algorithms on the extrachain are presented. Thirdly, both the extrachain selection algorithm and appending algorithm are proposed, so that the extrachain can be appended to the blockchain fairly and safely. Finally, an extrachain transmission scheme is presented to broadcast the blocks generated in the delayed network to the normal network. Theoretical analysis and simulation experiments further illustrate the efficiency of the proposed mechanism.

Operational Tests for Delay-Tolerant Network between the Moon and Earth Using the Korea Pathfinder Lunar Orbiter in Lunar Orbit

The Korea Pathfinder Lunar Orbiter (KPLO) was launched on 5 August 2022, equipped on the SpaceX Falcon 9 launch vehicle. At present, the KPLO is effectively carrying out its scientific mission in lunar orbit. The KPLO serves as a cornerstone for the development and validation of Korean space science and deep space technology. Among its payloads is the DTNPL, enabling the first-ever test of delay-tolerant network (DTN) technology for satellites in lunar orbit. DTN technology represents a significant advancement in space communication, offering stable communication capabilities characterized by high delay tolerance, reliability, and asymmetric communication speeds—a necessity for existing satellite and space communication systems to evolve. In this paper, we briefly give an overview of the Korea Lunar Exploration Program (KLEP) and present scientific data gathered through the KPLO mission. Specifically, we focus on the operational tests for DTN-ION conducted for message and file transfer, as well as real-time video streaming, during the initial operations of the KPLO. Lastly, this study offers insights and lessons learned from KPLO DTNPL operations, with the goal of providing valuable guidance for future advancements in space communication.

Comparison of two bundles for reducing surgical site infection in colorectal surgery: multicentre cohort study.

There is controversy regarding the maximum number of elements that can be included in a surgical site infection prevention bundle. In addition, it is unclear whether a bundle of this type can be implemented at a multicentre level. A pragmatic, multicentre cohort study was designed to analyse surgical site infection rates in elective colorectal surgery after the sequential implementation of two preventive bundle protocols. Secondary outcomes were to determine compliance with individual measures and to establish their effectiveness, duration of stay, microbiology and 30-day mortality rate. A total of 32 205 patients were included. A 50% reduction in surgical site infection was achieved after the implementation of two sequential sets of bundles: from 18.16% in the Baseline group to 10.03% with Bundle-1 and 8.19% with Bundle-2. Bundle-2 reduced superficial-surgical site infection (OR 0.74 (95% c.i. 0.58 to 0.95); P = 0.018) and deep-surgical site infection (OR 0.66 (95% c.i. 0.46 to 0.93); P = 0.018) but not organ/space-surgical site infection (OR 0.88 (95% c.i. 0.74 to 1.06); P = 0.172). Compliance increased after the addition of four measures to Bundle-2. In the multivariable analysis, for organ/space-surgical site infection, laparoscopy, oral antibiotic prophylaxis and mechanical bowel preparation were protective factors in colonic procedures, while no protective factors were found in rectal surgery. Duration of stay fell significantly over time, from 7 in the Baseline group to 6 and 5 days for Bundle-1 and Bundle-2 respectively (P < 0.001). The mortality rate fell from 1.4% in the Baseline group to 0.59% and 0.6% for Bundle-1 and Bundle-2 respectively (P < 0.001). There was an increase in Gram-positive bacteria and yeast isolation, and reduction in Gram-negative bacteria and anaerobes in organ/space-surgical site infection. The addition of measures to create a final 10-measure protocol had a cumulative protective effect on reducing surgical site infection. However, organ/space-surgical site infection did not benefit from the addition. No protective measures were found for organ/space-surgical site infection in rectal surgery. Compliance with preventive measures increased from Bundle-1 to Bundle-2.

Delay and Disruption Tolerant Networking for Terrestrial and TCP/IP Applications: A Systematic Literature Review

Delay and Disruption Tolerant Networking (DTN) is a network architecture created basically to overcome non-continuing connectivity. There has been a great deal of research on this topic, from space communication to terrestrial applications. Since there are still many places on earth where there is no means of communication, the focus of this work is on the latest. A systematic literature review (SLR) was performed to know the main issues and advances related to the implementation of DTN for terrestrial and TCP/IP applications, especially in places where telecommunication infrastructure is lacking. The result is a classification of papers based on key aspects, such as architecture, performance, routing, and applications. A matrix of all the papers about these aspects is included to help researchers find the missing piece and concrete terrestrial solutions. The matrix uses three colors, green, yellow, and red according to the focus, either high, medium, or low, so that it is easy to identify specific papers.

Prototipe Aplikasi Komunikasi Menggunakan Jaringan Delay Tolerant Network Pada Perangkat Seluler Android

In the current global context, the exchange of information through Internet networks has become increasingly vital, necessitating the effectiveness of communication technology. This is particularly true in areas with weak or unstable signal coverage such as intermittent areas. To address challenges such as frequent connection drops in these areas, Delay Tolerant Networking (DTN) architecture is offered as an alternative solution to overcome these problems. The conducted research aims to design and test a data communication application prototype using DTN architecture implemented on the Android operating system. The approach taken involves using the Analysis, Design, Development, Implementation, and Evaluation (ADDIE) method. In detail, the application is implemented on the Android operating system and integrates various routing protocols such as Epidemic, Spray and Wait, MaxProp, and ProphetV2 to optimize data transmission and reception under varying network conditions. Data collection techniques include measuring latency and data transfer speed in predetermined testing scenarios, while data analysis techniques involve evaluating the measurement results to determine the effectiveness of the routing protocols used. Evaluation is conducted and the results showing an average latency between 800-1400ms and speeds of 100-400kbps, depending on the distance and varying network conditions. This study validates the effectiveness of DTN in maintaining consistent communication in challenging network environments. The impact of this research on the advancement of informatics is to pave the way for further development and adaptation of DTN technology in various mobile applications and data networks.

Clinical impact of a multimodal pain management protocol for loop ileostomy reversal.

As introduced, multimodal pain management bundle for ileostomy reversal may be considered to reduce postoperative pain and hospital stay. The aim of this study was to evaluate clinical efficacy of perioperative multimodal pain bundle for ileostomy. Medical records of patients who underwent ileostomy reversal after rectal cancer surgery from April 2017 to March 2020 were analyzed. Sixty-seven patients received multimodal pain bundle protocol with ileostomy reversal (group A) and 41 patients underwent closure of ileostomy with conventional pain management (group B). Baseline characteristics, including age, sex, body mass index, American Society of Anesthesiologists classification, diabetes mellitus, and smoking history, were not significantly different between the groups. The pain score on postoperative day 1 was significant lower in group A (visual analog scale, 2.6 ± 1.3 vs. 3.2 ± 1.2; P = 0.013). Overall consumption of opioid in group A was significant less than group B (9.7 ± 9.5 vs. 21.2 ± 8.8, P < 0.001). Hospital stay was significantly shorter in group A (2.3 ± 1.5 days vs. 4.1 ± 1.5 days, P < 0.001). There were no significant differences between the groups in postoperative complication rate. Multimodal pain protocol for ileostomy reversal could reduce postoperative pain, usage of opioid and hospital stay compared to conventional pain management.

One-Hour Bundle Protocols for Surgical Sepsis and Septic Shock in Surgical Intensive Care Unit: Clinical Outcome Aspects in the Thai Context.

Surgical sepsis is a syndrome occurring during the perioperative period with a high mortality rate. Since the one-hour bundle protocol was recommended to decrease sepsis-related morbidity and mortality in clinical practice, the protocol has been applied to surgical patients with sepsis and septic shock. However, clinical outcomes in these surgical patients remain unknown. Thus, this study aimed to compare survival outcomes in patients before and after the implementation of one-hour bundle care in clinical practice. In thisprospective cohort study, 401 surgical patients with sepsis were divided into two groups, with 195 patients undergoing the one-hour bundle from December 25, 2021, to March 31, 2024, and 206 patients undergoing usual care from January 1, 2018, to December 24, 2021, before the one-hour bundle protocol was implemented by the Surviving Sepsis Campaign (SSC). Demographic data, treatment processes, and clinical outcomes were recorded. After the one-hour bundle protocol was applied in surgical practice, the median survival time was significantly increased in surgical patients who underwent one-hour bundle care (95% confidence interval (CI): 12.32-19.68) (p= 0.016). Factors influencing the increase in the mortality rate were delays in fluid resuscitation of >2 hours, vasopressor initiation of >2 hours, and empirical antibiotics of >5 hours (p= 0.017, 0.028, and 0.008, respectively). One-hour bundle care for surgical patients with sepsis resulted in an increased median survival time. Delays in fluid resuscitation (>2 hours), vasopressor initiation (>2 hours), and empirical antibiotics (>5 hours) were factors associated with mortality.

Prophylaxis for postoperative atrial fibrillation: Impact of the implementation of a medication bundle protocol

Prophylaxis for postoperative atrial fibrillation: Impact of the implementation of a medication bundle protocol

Reliable community card system for detecting and isolating selfish vehicles in smart and connected communities‐based VDTN's

AbstractSmart and connected communities (SCC) is a new area of the Internet of Things with the potential to improve people's lives. The goal of developing SCC for a community is to encourage people to focus on the present, consider the future, and reflect on the past. In SCC, nodes (vehicles) can use their mobility to collect data from interconnected devices and send it to a variety of delay‐tolerant applications. Vehicular delay tolerant networks are an ideal fit for such services. However, the problem is that the devices and nodes (vehicles), having limited resources, may become unwilling to cooperate due to their selfish behavior. This article presents a reliable community card system (RCCS) with two main parts: a reliable community and community‐based card tracking system (CBCTS). The reliable community contains all trustworthy vehicles with a certain level of community reputation determined by their honesty level. In CBCTS, every vehicle needs a community card to participate in the network and the neighboring vehicles act as monitoring vehicle. The evaluation results show that the proposed RCCS is quite effective, with detection time and packet delivery. Similarly, it causes minimal overhead and energy consumption compared to all other existing techniques.

Comparing Statistical, Analytical, and Learning-Based Routing Approaches for Delay-Tolerant Networks

In delay-tolerant networks (DTNs) with uncertain contact plans, the communication episodes and their reliabilities are known a priori. To maximise the end-to-end delivery probability, a bounded network-wide number of message copies are allowed. The resulting multi-copy routing optimization problem is naturally modelled as a Markov decision process with distributed information. In this paper, we provide an in-depth comparison of three solution approaches: statistical model checking with scheduler sampling, the analytical RUCoP algorithm based on probabilistic model checking, and an implementation of concurrent Q-learning. We use an extensive benchmark set comprising random networks, scalable binomial topologies, and realistic ring-road low Earth orbit satellite networks. We evaluate the obtained message delivery probabilities as well as the computational effort. Our results show that all three approaches are suitable tools for obtaining reliable routes in DTN, and expose a trade-off between scalability and solution quality.

Exploring the evolving landscape of human-centred crisis informatics: current challenges and future trends

Abstract Modern Information and Communication Technology (ICT) has been used in safety-critical situations for over twenty years. Rooted in Human-Computer Interaction (HCI) and related disciplines, the field of crisis informatics made considerable efforts to investigate social media use and role patterns in crises, facilitate the collection, processing and refinement of social media data, design and evaluate supportive ICT, and provide cumulative and longitudinal research. This narrative review examines contemporary challenges of human-centred crisis informatics and envision trends for the following decade, including (I) a broadening scope of crisis informatics, (II) the professionalisation of cross-platform collaboration of citizen communities and emergency services, (III) expert interfaces for explainable and multimodal artificial intelligence for user-generated content assessment, (IV) internet of things and mobile apps for bidirectional communication and warnings in disruption-tolerant networks, as well as (V) digital twins and virtual reality for the effective training of multi-agency collaboration in hybrid hazards.

Space System Internetworking: The Foundational Role of Delay and Disruption-Tolerant Networking

Space System Internetworking: The Foundational Role of Delay and Disruption-Tolerant Networking

Nurses’ Knowledge on the Prevention of Ventilator-Associated Pneumonia (VAP) among Critically Ill Patients

Background: Ventilator-associated pneumonia (VAP) is a significant concern in healthcare settings, particularly among critically ill patients who require mechanical ventilation. Nurses play a vital role in preventing VAP through their knowledge and implementation of evidence-based practices. However, there exists a notable gap in the research regarding nurses’ knowledge of preventing VAP to improve patient outcomes and reduce healthcare costs.Purpose: This study aimed to assess nurses’ knowledge of preventing VAP among critically ill patients using the ventilator bundle checklist.Methods: This study used a one-group pretest-posttest design to test the change in the nurses’ knowledge scores on VAP working in two government hospitals in Buraidah, Al Qassim Region, Saudi Arabia. The study covered 250 purposively and conveniently sampled nurses from intensive care units. Data collection was performed in three phases: pre-test, VAP educational program, and post-test. Data were collected using self-administered questionnaires on nurses’ socio-demographics, a 20-item self-made survey about the knowledge of VAP and its prevention and the adapted ventilator bundle checklist. The collected data were entered, prepared, and analyzed using SPSS version 25.0. Relevant ethical issues were strictly considered.Results: The results showed that during the pre-test, correct responses were accounted for but showed low scores in the following areas: general knowledge of VAP (27.6%), factors associated with VAP (36%), international guidelines for prevention (20.8%), and nurses’ roles in prevention (16.4%). However, in the post-test, there was a remarkable increase in the knowledge scores in the same categories (95.2%) on general knowledge, on factors associated with VAP (74.8%), on international guidelines (73.6%) and on nurses’ roles in prevention (61.6%). The program significantly improved overall VAP knowledge and knowledge in specific areas like general VAP, associated factors, international guidelines, and nurses’ roles in prevention (p&lt;0.000).Conclusion: A pre-test revealed low baseline knowledge across all four areas assessed: general VAP knowledge, factors associated with VAP, international VAP prevention guidelines, and nurses’ roles in VAP prevention. However, post-test scores markedly increased in all areas, indicating the educational program’s effectiveness. Hence, the findings suggest that educational intervention focused on VAP screening and bundle protocols could be beneficial to address the gap in knowledge on VAP.

All about Delay-Tolerant Networking (DTN) Contributions to Future Internet

Although several years have passed since its first introduction, the significance of Delay-Tolerant Networking (DTN) remains evident, particularly in challenging environments where traditional networks face operational limitations such as disrupted communication or high latency. This survey paper aims to explore the diverse array of applications where DTN technologies have proven successful, with a focus on emerging and novel application paradigms. In particular, we focus on the contributions of DTN in the Future Internet, including its contribution to space applications, smart cities and the Internet of Things, but also to underwater communications. We also discuss its potential to be used jointly with information-centric networks to change the internet communication paradigm in the future.

Performance assessment of routing protocols for campus area emergency delay-tolerant network

Handheld devices have recently become an indispensable part of our daily lives. These devices always require an end-to-end connection for proper message transmission. Message transmission will be halted if the connection fails. In this case, delay-tolerant networks (DTNs) are preferable. One of the most important applications of DTN is the transmission of emergency messages among rescue personnel in the aftermath of a disaster. Previously, we created a simulation map in the Rajshahi University (RU) campus area of Bangladesh and studied the performance of DTN routing protocols. This paper used our developed simulation map to evaluate the performance of DTN and social-based routing protocols for emergency message circulation in the RU campus area when traditional communication networks are unavailable. We conducted extensive experiments with the opportunistic network environment (ONE) simulator for evaluations. The performance analysis is based on the delivery ratio, average latency, transmission cost, and average hop count of each group when the message size and node density are changed. According to the simulation results, dLife outperforms all other routing protocols in terms of delivery ratio, while the Spray-and-Focus routing protocol outperforms all other performance metrics.

The need for standardized perioperative care for patients undergoing bariatric and metabolic surgery in the United Kingdom.

Enhanced recovery after surgery (ERAS) protocols are shown to improve patient outcomes and reduce length of hospital stay. However, there is currently limited consensus on the perioperative management of patients undergoing bariatric and metabolic surgery (BMS) in the United Kingdom. This study aims to survey the level of consistency in patient care undergoing BMS. Bariatric nurse specialists from 30 bariatric units completed an anonymised, online survey from 21 December 2022 to 21 February 2023. Most units (77%) have implemented a premade postoperative care bundle protocol including predetermined timing of oral intake (77%) and postoperative day 1 bloods (60%). 63% of units have also established pre-set analgesia and anti-emetic bundles. Date of discharge is variable, ranging from 1 day after surgery (50%) to a 'two night stay' protocol (33%) to within 4 days after surgery (17%). Most follow-up clinics are either led by dietitians (33%) or both bariatric nurse specialists and dietitians collaboratively (57%). Patients are usually established on solid food 6 weeks after surgery in 53% (16/30) units. Chemical venous thromboembolism (VTE) prophylaxis was either given on day of surgery postoperatively (60%), day before (20%) or after (17%) surgery. Our study shows significant variability of care throughout the surgical pathway, in the study population. The results suggest a need for consensus guidelines outlining the best-practice approach to managing patients undergoing BMS; due to the heterogeneity of the patient group, these guidelines should contain overarching generalisable recommendations that can then be tailored to individual patients.