Search

The evolution of wireless body area network (WBAN) has changed the human life for its applications in the field of healthcare, fitness, entertainment and sports etc. However, two of the major challenges in the design of WBAN are energy efficiency and guaranteeing QoS. The load balance of different packet queues in a WBAN plays important role in design of energy efficient and reliable system. In this paper, we propose a Traffic Prioritized Load Balanced Scheduling (TPLBS) algorithm for load balancing in different priority queues in wireless body area networks based on IEEE 802.15.6 model. The main objective of this paper is to minimize packet drop in the queues so that throughput of WBAN can be improved. In this case we consider both priority and location from which the packet received, so that no packet should wait for a long time in the assigned queue to be transmitted to Access Point. The proposed method is simulated using Castalia to study and compare its performance with its counterparts. The simulation results reveal that the proposed protocol works better than the existing methods in terms of delay, throughput and energy efficiency.

When designing Wireless Sensor Networks it is important to analyze their security risks and provide adequate solutions for protecting them from malicious attacks. Unfortunately, perfect security cannot be achieved, for performance reasons. Therefore, designers have to devise security priorities, and select security mechanisms accordingly. However, in the early stages of the design process, the concrete effects of security attacks on the system may not be clearly identified. In this paper, we propose a framework that integrates formal verification and network simulation for enabling designers to evaluate the effects of attacks, identify possible security mechanisms, and evaluate their effectiveness, since design time. Formal methods are used to build the abstract model of the application, together with a set of attacks, and to state properties of general validity. The simulator measures the impact of the attacks in terms of common network parameters, like energy consumption or computational effort. Such information can be used to select adequate security mechanisms, then the initial abstract model can be refined to adopt them, and finally prove that former system properties are still verified. The framework relies on UPPAAL for formal modeling and verification and uses the Attack Simulation Framework on top of Castalia as a network simulator. As proof of concept, a case study is shown.

The wireless sensor network (WSN) has been extensively used to monitor and control the natural ecosystem on a large scale like air quality, natural life, etc. Low battery power,low storage, and limited processing ability are the most critical areas of concern in WSN. To reduce energy utilization, the sensor nodes in WSN work in a cyclic process between active and sleep mode. A certain number of nodes are chosen active and they are responsible for sensing as well as data transmission and rest of the nodes are gone to sleep. In order to lengthen the lifetime of network, in this paper we proposed a level wise periodic tree construction algorithm that uses a specific set of nodes to participate in tree construction, instead of all the nodes, to minimize the energy consumption. In this proposed approach, the main idea is to put the nodes, which are currently active and have already spent a significant amount of energy, to sleep mode, while giving chances to the leaf nodes, which has comparatively spent less energy, to become an active node and maintain connectivity. The performance of the proposed protocol is evaluated using the Castalia simulator. The simulation results show that the proposed level-wise periodic tree construction approach increases the durability of the network in conjunction with the non-level approach.

Wireless body area networks (WBANs) are usually used to collect and monitor health-related information for both critical and non-critical patients. However, the traditional WBAN communication framework is unable to guarantee the successful delivery of critical information due to a lack of administrative control and priority support for emergency data. To overcome these issues, this paper proposes a novel software-defined networking (SDN)-based WBAN (SDWBAN) framework for application-specific traffic management. An application classification algorithm and a packet flow mechanism are developed by incorporating SDN principles with WBAN to effectively manage complex and critical traffic in the network. Furthermore, a Sector-Based Distance (SBD) protocol is designed and utilized to facilitate the SDWBAN communication framework. Finally, the proposed SDWBAN framework is evaluated through the CASTALIA simulator in terms of Packet Delivery Ratio (PDR) and latency. The experimental outcomes show that the proposed system achieves high throughput and low latency for emergency traffic in SDWBANs.

[EN] Neighbor discovery is an important first step after the deployment of ad hoc wireless networks since they are a type of network that do not provide a communications infrastructure right after their deployment, the devices have radio transceivers which provide a limited transmission range, and there is a lack of knowledge of the potential neighbors. In this work two proposals to overcome the neighbor discovery in static one-hop environments in the presence of collisions, are presented. We performed simulations through Castalia 3.2, to compare the performance of the proposals against that for two protocols from the literature, i.e. PRR and Hello, and evaluate them according to six metrics. According to simulation results, the Leader-based proposal (O(N)) outperforms the other protocols in terms of neighbor discovery time, throughput, discoveries vs packets sent ratio, and packets received vs sent ratio, and the TDMA-based proposal is the slowest (O(N-2)) and presents the worst results regarding energy consumption, and discoveries vs packets sent ratio. However, both proposals follow a predetermined transmission schedule that allows them to discover all the neighbors with probability 1, and use a feedback mechanism. We also performed an analytical study for both proposals according to several metrics. Moreover, the Leader-based solution can only properly operate in one-hop environments, whereas the TDMA-based proposal is appropriate for its use in multi-hop environments., This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.

In Wireless Sensor Networks (WSNs), clustering techniques are often used to optimize energy consumption and increase Packet Delivery Rate (PDR). To date, most of the proposed clustering protocols assume that there is a Line of Sight (LOS) between all the sensors. In fact, most of the available WSN simulators assume the use of optimistic path loss models that neglect the effect of obstacles on the PDR. However, in real situations such as in 3D terrains, obstacles can interfere this LOS. Moreover, while clustering, it is also important to maintain the coverage of a given Region of Interest (ROI). Therefore, finding an integrated solution for both clustering and coverage problems in an irregular 3D field becomes a pressing concern. In this paper, we first adopt an obstacle-aware path loss model to reflect the effect of obstacles on the communication between any pair of sensors. To that end, the Castalia simulator is adapted to use this proposed path loss model. Then, we introduce a Coverage and Obstacle-Aware Cluster Head Selection (COACHS) protocol to solve the cluster heads selection problem while maintaining a good coverage of a WSN deployed in an irregular 3D field. Simulation results demonstrate that the effect of obstacles on the PDR cannot be neglected. Moreover, comparative evaluation results show that COACHS outperforms other competent protocols in terms of PDR while simultaneously maintaining an acceptable energy consumption and a good coverage of the ROI.

Research in wireless body area network (WBAN) has gained interest and has become an emerging health service application because of the potential for its use in continuous monitoring of human well-being. The natural human body movements and environmental interference impose difficulties on WBAN performance, such as operational lifetime and data delivery reliability. This work proposes a cross-layer approach, called CL, based on the IEEE 802.15.4 standard to guarantee quality of service in terms of packet delivery and network lifetime. The proposed protocol is compared to the original standard and results suggest that CL outperforms when interference is the cause of packet delivery failures.

Ambient assisted living (AAL) is focused on providing assistance to patients primarily in their natural environment to improve their quality of life. AAL domain has evolved at a fast pace as the stakeholders of AAL include patients and their relatives, social services, and care givers. AAL follows a multi-tier architecture where data from body area sensor network (BAN) gets routed through the coordinator of such networks via cellular devices or display co-ordinators at hospitals to a remote server over the Internet. A BAN configuration comprises of wearable and/or implantable sensors attached to a patient that are connected to a coordinator node carried by the patient. Though many routing protocols are proposed for routing within BAN, the challenges behind routing data from the coordinator of BAN to the cellular devices or display co-ordinators at hospitals is hardly investigated. But this routing is important for establishing end-to-end communication in AAL. Consequently, in this paper, we propose a multi-hop routing protocol that routes data from body sensor networks to the cellular devices or display co-ordinators. In a hospital scenario, there can be multiple display co-ordinators in vicinity of a coordinator of BAN, thus making this routing problem multi-sink one. Moreover, in a hospital, there can be multiple patients having wearable or implantable sensors attached to them forming multiple BAN configurations in vicinity. Thus, packet transmission from BAN coordinator may interfere with the transmission of a neighboring one. The proposed routing protocol is designed to avoid such inter BAN interference. The protocol is simulated using Castalia simulator and results show that the proposed protocol achieves better balance between energy efficiency and throughput as compared to state-of-the-art algorithms.

The link quality protocols of the IEEE 802.15.4 show low performance in terms of reliability in a hospital environment. To achieve the optimal performance of these protocols, this paper proposes a fuzzy logic-based solution using a detailed empirical reliability assessment. This paper provides a solution through four steps: 1) identifying the suitable IEEE 802.15.4 protocols and validating their suitability for patient monitoring systems through simulation in Castalia 3.2 with the OMNet++ platform; 2) providing a detailed discussion and analysis regarding link quality mechanisms used; 3) creating a real-time test bed to perform the empirical experiments to find the actual link quality estimation for different hospital environments; and 4) proposing a fuzzy logic system (FLS), which maps the results of empirical experiments with the proposed FLS to obtain the optimal results. For empirical experiments, we divide the communication in the hospital into four environmental scenarios, including inside ward, corridor, ward to corridor, and ward to ward. Both mobile and static scenarios are considered with line of sight and non-line of sight. Different link quality threshold values for link quality indicator (LQI) and received signal strength indicator (RSSI) are found for the variety of hospital scenarios. A strong correlation is noticed between LQI and packet reception rate in most of the scenarios, whereas a weak correlation is found between RSSI and packet reception rate. Finally, the results are mapped to our proposed FLS to obtain the optimal performance.

Changes in the BAN topology are caused due to the body movement induced by repeated activities like walking, running, twisting, turning and waving arms. In such activities, individual nodes may move relative to each other and along with this, the entire BAN may move its absolute location, which can induce several complexities in the network like re-transmission, collision, overhearing and changing interference. This paper presents a scheme referred as, posture based data transmission (PBDT) with the objective of efficient data transmission. PBDT is based on the occurrence of potential (best) posture over time in repeated activities. In PBDT, each node follows the procedures: (a) recognized the sequence of postures by observing the variation of received signal strength indicator (RSSI) from neighbor nodes over time, (b) finds the best posture from posture sequence for data transmission, (c) maintains a dynamic active/sleep schedule in order to reduce lossy transmission, collision and overhearing. Here, we consider walking as a repeated action over time to check the validity of the proposed mechanism. PBDT is implemented using Castalia simulator and compared with selected MAC protocols. The results are analyzed in respect to the energy consumption and throughput.

Wireless sensors networks (WSNs) are characterized by flexibility and scalability in any environment. These networks are increasingly used in agricultural and industrial environments and have a dual role in data collection from sensors and transmission to a monitoring system, as well as enabling the management of the monitored environment. Environment management depends on trust in the data collected from the surrounding environment, including the time of data creation. This paper proposes a trust model for monitoring humidity and moisture in agricultural and industrial environments. The proposed model uses a digital signature and public key infrastructure (PKI) to establish trust in the data source, i.e., the trust in the sensor. Trust in data generation is essential for real-time environmental monitoring and subsequent analyzes, thus timestamp technology is implemented here to further ensure that gathered data are not created or changed after the assigned time. Model validation is performed using the Castalia network simulator by testing energy consumption at the receiver and sender nodes and the delay incurred by creating or validating a trust token. In addition, validation is also performed using the Ascertia TSA Crusher application for the time consumed to obtain a timestamp from the free TSA. The results show that by applying different digital signs and timestamps, the trust entity of the WSN improved significantly with an increase in power consumption of the sender node by up to 9.3% and receiver node by up to 126.3% for a higher number of nodes, along with a packet delay of up to 15.6% and an average total time consumed up to 1.186 s to obtain the timestamp from the best chosen TSA, which was as expected.

Software-Defined Networking (SDN) offers an abstract view of the network and assists network operators to control the network traffic and the associated network resources more effectively. For the past few years, SDN has shown a lot of merits in diverse fields of applications, an important one being the Wireless Body Area Network (WBAN) for healthcare services. With the amalgamation of SDN with WBAN (SDWBAN), the patient monitoring and management system has gained much more flexibility and scalability compared to the conventional WBAN. However, the performance of the SDWBAN framework largely depends on the controller which is a core element of the control plane. The reason is that an optimal number of controllers assures the satisfactory level of performance and control of the network traffic originating from the underlying data plane devices. This paper proposes a mathematical model to determine the optimal number of controllers for the SDWBAN framework in healthcare applications. To achieve this goal, the proposed mathematical model adopts the convex optimization method and incorporates three critical SDWBAN factors in the design process: number of controllers, latency and number of SDN-enabled switches (SDESW). The proposed analytical model is validated by means of simulations in Castalia 3.2 and the outcomes indicate that the network achieves high level of Packet Delivery Ratio (PDR) and low latency for optimal number of controllers as derived in the mathematical model.

The emergence of biomedical sensor devices, wireless communication, and innovation in other technologies for healthcare applications result in the evolution of a new area of research that is termed as Wireless Body Area Networks (WBANs). WBAN originates from Wireless Sensor Networks (WSNs), which are used for implementing many healthcare systems integrated with networks and wireless devices to ensure remote healthcare monitoring. WBAN is a network of wearable devices implanted in or on the human body. The main aim of WBAN is to collect the human vital signs/physiological data (like ECG, body temperature, EMG, glucose level, etc.) round-the-clock from patients that demand secure, optimal and efficient routing techniques. The efficient, secure, and reliable designing of routing protocol is a difficult task in WBAN due to its diverse characteristic and restraints, such as energy consumption and temperature-rise of implanted sensors. The two significant constraints, overheating of nodes and energy efficiency must be taken into account while designing a reliable blockchain-enabled WBAN routing protocol. The purpose of this study is to achieve stability and efficiency in the routing of WBAN through managing temperature and energy limitations. Moreover, the blockchain provides security, transparency, and lightweight solution for the interoperability of physiological data with other medical personnel in the healthcare ecosystem. In this research work, the blockchain-based Adaptive Thermal-/Energy-Aware Routing (ATEAR) protocol for WBAN is proposed. Temperature rise, energy consumption, and throughput are the evaluation metrics considered to analyze the performance of ATEAR for data transmission. In contrast, transaction throughput, latency, and resource utilization are used to investigate the outcome of the blockchain system. Hyperledger Caliper, a benchmarking tool, is used to evaluate the performance of the blockchain system in terms of CPU utilization, memory, and memory utilization. The results show that by preserving residual energy and avoiding overheated nodes as forwarders, high throughput is achieved with the ultimate increase of the network lifetime. Castalia, a simulation tool, is used to evaluate the performance of the proposed protocol, and its comparison is made with Multipath Ring Routing Protocol (MRRP), thermal-aware routing algorithm (TARA), and Shortest-Hop (SHR). Evaluation results illustrate that the proposed protocol performs significantly better in balancing of temperature (to avoid damaging heat effect on the body tissues) and energy consumption (to prevent the replacement of battery and to increase the embedded sensor node life) with efficient data transmission achieving a high throughput value.

Wireless sensor networks (WSNs) can be used to support monitoring activities in a wide range of applications and communication environments. Its usage in extreme conditions, in what concerns pressure, temperature, and humidity, must be carefully assessed before the network deployment. In particular, the temperature variations have a direct impact upon the behavior of WSNs through the batteries of sensor nodes. These electrochemical devices are highly susceptible to temperature variations, which modifies the offered effective charge capacity. In this context, it is difficult to estimate the behavior of batteries over time, impairing the extraction of relevant information for energy-aware approaches. Such information, particularly battery state of charge, voltage, and lifetime, is often used by WSN simulators to predict the communication behavior in different scenarios. Nevertheless, WSN simulators generally use simplistic battery models, causing significant deviations in simulation results when compared with actual WSN deployments. This paper describes the implementation of the Temperature-Dependent Kinetic Battery Model (T-KiBaM) in the Castalia simulator, which enables a considerable improvement of the accuracy of simulations in communication environments with different temperature conditions. An experimental assessment has been performed with temperature variations over time to validate the usage of the T-KiBaM battery model. The experimental results indicate that the T-KiBaM model is quite accurate when estimating battery behavior under both different temperature set points and different temperature variations.

Wireless sensor networks have changed the way different types of data can be retrieved in a lot of monitoring scenarios. In this context, when sensors are equipped with a low-power camera, image snapshots may be gathered from the monitored field, but more complexity is involved when image packets have to be processed and transmitted. In general, the development of wireless sensor networks can rely on simulation tools to support performance evaluation and validation of new algorithms and protocols, avoiding additional time and money with the deployment of real networks. However, most simulation tools do not have proper resources for simulation of image transmissions, making harder simulations of those communications in sensor networks. This article describes the development of a new extension for the simulation tool Castalia/OMNeT++, named VisualCastalia. That extension provides additional resources for simulation of image transmissions, adding new resources for creation and validation of communication scenarios where one or more source nodes transmit image packets. It is expected that the developed extension can support research efforts in this area, bringing valuable results.

Wireless Sensor Networks (WSNs) are increasingly used in industrial applications such as the Internet-of-Things, Smart City technologies and critical infrastructure monitoring. Industrial WSNs often operate in a cluster or star configuration. To ensure real-time and predictable performance, link access is typically managed using time-slotted superframe methods. These methods generally use static and potentially inefficient slot assignments. In this paper, we propose to dynamically readjust time slot lengths as a technique to minimize overall energy consumption. Our approach combines real-time performance guarantees with energy conservation methods through a set of dynamic modulation based adaptive packet transmission scheduling algorithms that are designed to reclaim unused slot times. To support our reclaiming method in a wireless environment we introduce a novel low-power listening technique called reverse-low-power listening (RLPL) as part of an overall Hybrid Low-Power Listening (HLPL) protocol. We evaluate our algorithms using Castalia simulator against an oracle-based approach, and show that our dynamic slot reclaiming approach, coupled with HLPL, can introduce substantial power savings without sacrificing real-time support which may be a new approach towards improving industrial wireless standards.

eHealth applications have become essential in everyday life healthcare especially for elderly and sick individuals. To provide efficiency to such applications, many standards emerged for WBANs. However, WBANs standards showed their limits in terms of QoS and priorities differentiation depending on applications need. In this paper, we investigate IEEE 802.15.6 MAC performance efficiency and we define TA-802.15.6, an enhanced IEEE 802.15.6 CSMA/CA channel access mechanism. We aim to differentiate all IEEE 802.15.6 priorities traffics and to improve IEEE 802.15.6 based networks performances. Our main contribution is the enhancement of IEEE 802.15.6 CSMA/CA retransmission and packet drop processes. We also defined a new algorithm for dynamic backoff bounds assignment according to IEEE 802.15.6 priorities and to the network traffic state. We make an analytical evaluation through a new 4D Markov chain and by simulation based on Castalia. Results validate that the enhanced IEEE 802.15.6 CSMA/CA version provides a better service differentiation through accentuating priority differentiation and a better QoS in terms of reliability, throughput and energy consumption.

Compression sensing approaches have been used extensively with the idea of overcoming the limitations of traditional sampling theory and applying the concept of pressure during the sensing procedure. Great efforts have been made to develop methods that would allow data to be sampled in compressed form using a much smaller number of samples. Wireless body area networks (WBANs) have been developed by researchers through the creation of the network and the use of miniature equipment. Small structural factors, low power consumption, scalable data rates from kilobits per second to megabits per second, low cost, simple hardware deployment, and low processing power are needed to hold the wireless sensor through lightweight, implantable, and sharing communication tools wireless body area network. Thus, the proposed system provides a brief idea of the use of WBAN using IEEE 802.15.4 with compression sensing technologies. To build a health system that helps people maintain their health without going to the hospital and get more efficient energy through compression sensing, more efficient energy is obtained and thus helps the sensor battery last longer, and finally, the proposed health system will be more efficient energy, less energy-consuming, less expensive and more throughput.

Information gathered from the Smart Grid (SG) devices located in end user premises provides a valuable resource that can be used to modify the behavior of SG applications. Decentralized and distributed deployment of neighborhood area network (NAN) devices makes it a challenge to manage SG efficiently. The NAN communication network architecture should be designed to aggregate and disseminate information among different SG domains. In this paper, we present a communication framework for NAN based on wireless sensor networks using the software defined networking paradigm. The data plane devices, such as smart meters, intelligent electronic devices, sensors, and switches are controlled via an optimized controller hierarchy deployed using a separate control plane. An analytical model is developed to determine the number of switches and controllers required for the NAN and the results of several test scenarios are presented. A Castalia based simulation model was used to analyze the performance of modified NAN performance.

Sensors cooperate and coordinate with each other to disseminate sensed data in the network. In establishing coordination among sensors such that they can access the shared wireless medium, Medium Access Control (MAC) protocol plays an important role. In this article, we presented an analytical study on some popular MAC protocols for Wireless Sensor Networks (WSNs). Based on the design techniques, MAC protocols for WSNs are classified into two main categories: single-layer and cross-layer. MAC protocols such as S-MAC, T-MAC, B-MAC and X-MAC are selected to study the design approaches of single-layer genre. BoX-MAC-1 and BoX-MAC-2 are selected to analyze cross-layer design approaches. This survey paper aims at reporting an implementation viewpoint of different design approaches of MAC protocols in WSN. We have considered mixed WSNs that exhibits node movement (e.g., static, mobile) and changes in communication medium (e.g., air, water). Representative protocols are implemented in Castalia simulator and evaluated on the basis of important performance metrics such as energy consumption, network lifetime, throughput and end-to-end delay. The merits and demerits of different protocols are also compared.

In recent days, intelligent biomedical sensors and wearable devices are changing the healthcare industry by providing various heterogeneous vital signs of patients to the hospitals, caregivers, and clinicals. This collective form of monitoring sensor devices forms a very short-range Wireless Body Area Network (WBAN) and plays a key role in the data gathering process. If any sensor node in the network detects abnormal values that should be transmitted promptly via wireless medium with less delay. A single medium allows one-way delivery of a data packet, and it may not be sufficient to satisfy the high volume of communication demand between the sensor nodes in the network. In the same way, the packet prioritization does not guarantee the packet will get there on time and sometime it may cause priority conflicts among the nodes. It is only mean that the flow of delivery service handles that critical data packet before handling other data packets. However, unexploited time slots and bandwidth wastage will occur due to inefficient backoff management and collisions. To minimize the aforementioned issues, various backoff procedures, adaptive slot allocation mechanisms, priority-based medium access control protocols have been developed but suffer limitations in the context of providing priority-based channel access with less backoff conflicts and dedicated allocation of time slots for critical nodes in all cases. Based on these deliberations, a more effective Traffic Priority-based Channel Access Technique (TP-CAT) is proposed using IEEE 802.15.6 in order to minimize the transmission delay of critical data packet and solve conflicts among other priority nodes during the backoff phases. Firstly, a Low Threshold Criticality-based Adaptive Time slot Allocation algorithm (LT-CATA) is presented to decrease the priority slot conflicts between the low threshold data traffic from the same and different type of user priority nodes. Secondly, a High Threshold Criticality-based Adaptive Time slot Allocation algorithm (HT-CATA) is developed to reduce the priority slot conflicts between the high threshold data traffic from the same and different types of user priority nodes. Additionally, a novel Random Overlapping Backoff value Avoidance (ROBA) technique is introduced to eliminate the overlapping issue during the selection of random backoff value among the sensor nodes. Since, the proposed technique greatly reduced the channel access delay and transmission delay of critical data packet as well as other types of priority data packet. The Simulation results are verified in the CASTALIA 3.2 framework using omnet++ network simulater to relatively evaluate the performance metrics of the TP-CAT technique with state-of-the-art protocols. From the analysis of the results, it is evident that the TP-CAT technique provides better performance in terms of delay, energy consumption, and throughput in healthcare monitoring environments.

The rapid development of Internet of Things has triggered the multiplication of communication nodes based on Radio-Frequency Identification (RFID) and Wireless Sensor Networks (WSNs) in various domains such as building, city, industry, and transport. These communication nodes are attached to a thing or directly included in the material of the thing to form a communicating material. In communicating material, one of the desired objectives is to merge the logical data with its physical material, thus simplifying the monitoring of its life cycle, the maintenance operations, and the recycling process. In this context, the initial form of the communicating material can evolve during its lifecycle. It can be split, aggregated with other materials, or partially damaged. However, the entire information in the material should always be accessible after each change. Thus, the objective of this research is to develop specific algorithms for efficient dissemination of information in the material in order to limit information losses. Two dissemination algorithms hop-counter-based and probabilistic-based are proposed for storing data by using WSNs, and non-localized and localized storage is considered. Non-localized storage ensures that information can be retrieved from each piece of the material by using a uniform data replication process. Localized storage ensures that the information is stored in a limited region of the material. Castalia/OMNeT++ simulator is used to compare the performance of the proposed algorithms with other similar protocols such as DEEP, Supple, and RaWMS. This work focuses on the definition of new communicating materials (e.g. concrete and wood brick) using Wireless Sensor Networks.In this article, thousands of micro-sensors nodes are embedded into the material. Thus, the data could be stored in the memory of sensor nodes.New unstructured proactive data dissemination algorithms are developed to store the information in the communicating materials.A simulation study is developed using Castalia/OMNeT++ Tools.The solutions are compared with the most known unstructured proactive data dissemination protocols for Wireless Sensor Networks.

Wireless sensor networks are exposed to various kinds of security threat. The node replication attack is application-independent and can be launched by an adversary just by capturing a single sensor from the network. The post-capture impact of this attack is serious as an adversary can launch various insider attacks with the help of replicas that are deployed in the network. Counter-measures for node replication attack have drawn the attention of many researchers in this field. The first step towards handling a node replication attack is to detect the existence of replicas and remove them from the network. A number of replica detection schemes have been proposed in the literature. However, only a few survey articles exist based on replica detection schemes. Most of these survey lacks comparative analysis on the existing schemes, and are limited only to a few referred schemes. In this paper, we have classified the existing replica detection schemes considering a higher number of parameters than the existing schemes, and highlighted advantages and disadvantages of the contributions. A detailed comparative analysis of the existing schemes are made based on their communication cost, message overhead, storage requirement, and number of replica detectors per node. We have simulated a few mostly referred detection schemes using Castalia and analysed their performance in terms of detection probability, average number of packets sent/received, detection time, and energy consumption.

Recently, increasing demand for remote healthcare monitoring systems poses a specific set of Quality of Services (QoS) requirements to the MAC layer protocols and standards (IEEE 802.15.6, IEEE 802.15.4, etc.) of Wireless Body Area Sensor Networks (WBASNs). They mainly include time bounded services (latency), reliable data transmission, fair channel distribution, and specified data rates. The existing MAC protocols of WBASNs are lack of a specific set of QoS. To address this, the paper proposes a QoS profile named delay, reliability, and throughput (DRT). The QoS values computed through DRT profile provide maximum reliability of data transmission within an acceptable latency and data rates. The DRT is based on the carrier sense multiple access with collision avoidance (CSMA/CA) channel access mechanism and considers IEEE 802.15.4 (low-rate WPAN) and IEEE 802.15.6 (WBASN). Further, a detailed performance analysis of different frequency bands is done which are standardized for WBASNs, that is, 420 MHz, 868 MHz, 2.4 GHz, and so forth. Finally, a series of experiments are conducted to produce statistical results for DRT profile with respect to delay, reliability, and packet delivery ratio (PDR). The calculated results are verified through extensive simulations in the CASTALIA 3.2 framework using the OMNET++ network simulator.

Localization in wireless sensor networks not only provides a node with its geographical location but also a basic requirement for other applications such as geographical routing. Although a rich literature is available for localization in static WSN, not enough work is done for mobile WSNs, owing to the complexity due to node mobility. Most of the existing techniques for localization in mobile WSNs uses Monte-Carlo localization, which is not only time-consuming but also memory intensive. They, consider either the unknown nodes or anchor nodes to be static. In this paper, we propose a technique called Dead Reckoning Localization for mobile WSNs. In the proposed technique all nodes (unknown nodes as well as anchor nodes) are mobile. Localization in DRLMSN is done at discrete time intervals called checkpoints. Unknown nodes are localized for the first time using three anchor nodes. For their subsequent localizations, only two anchor nodes are used. The proposed technique estimates two possible locations of a node Using Bezouts theorem. A dead reckoning approach is used to select one of the two estimated locations. We have evaluated DRLMSN through simulation using Castalia simulator, and is compared with a similar technique called RSS-MCL proposed by Wang and Zhu ., Journal Paper, IET Wireless Sensor Systems, 2015

This paper presents a leader-based approach to routing in Mobile Wireless Sensor Networks (MWSN). Using local information from neighbour nodes, a leader election mechanism maintains a spanning tree in order to provide the necessary adaptations for efficient routing upon the connectivity changes resulting from the mobility of sensors or sink nodes. We present two protocols following the leader election approach, which have been implemented using Castalia and OMNeT++. The protocols have been evaluated, besides other reference MWSN routing protocols, to analyse the impact of network size and node velocity on performance, which has demonstrated the validity of our approach. Research supported by the Spanish Research Council (MINECO), Grant TIN2016-79897-P, and the Department of Education, Universities and Research of the Basque Government, Grant IT980-16.

Recently, interest in the Wireless Body Area Network (WBAN) for patient monitoring has grown significantly. Therefore, very interesting researches are concentrating on enhancing patient monitoring systems that require quality of services provisioning at different levels and especially in communication between WBAN nodes. Therefore, the conception of an efficient MAC (Medium Access Control) protocol is required to satisfy the stringent monitoring system requirements. In this context, investigations related to the most efficient and recent WBAN MAC protocols are carried out taking in consideration the requirements of WBAN MAC protocols, and the MAC proposals classification is presented in this paper. Furthermore, to illustrate the performance of the recently drafted IEEE 802.15.6 standard, IEEE 802.15.4 (Zigbee MAC) and TMAC protocols in different working conditions, we have elaborated different scenarios to simulate these protocols using CASTALIA framework and OMNET++ network simulator. Besides that, we have also computed the end-to-end delay (E2E) in the worst case for those protocols.

A link level reliable multicast requires a channel access protocol to resolve the collision of feedback messages sent by multicast data receivers. Several deterministic media access control protocols have been proposed to attain high reliability, but with large delay. Besides, there are also protocols which can only give probabilistic guarantee about reliability, but have the least delay. In this paper, we propose a virtual token-based channel access and feedback protocol (VTCAF) for link level reliable multicasting. The VTCAF protocol introduces a virtual (implicit) token passing mechanism based on carrier sensing to avoid the collision between feedback messages. The delay performance is improved in VTCAF protocol by reducing the number of feedback messages. Besides, the VTCAF protocol is parametric in nature and can easily trade off reliability with the delay as per the requirement of the underlying application. Such a cross layer design approach would be useful for a variety of multicast applications which require reliable communication with different levels of reliability and delay performance. We have analyzed our protocol to evaluate various performance parameters at different packet loss rate and compared its performance with those of others. Our protocol has also been simulated using Castalia network simulator to evaluate the same performance parameters. Simulation and analytical results together show that the VTCAF protocol is able to considerably reduce average access delay while ensuring very high reliability at the same time.

In the gravity field of an asteroid with the second order and degree harmonics C 20 and C 22, the attitude stability of a spacecraft with two flexible solar arrays on a stationary orbit subjected to the fourth-order gravity gradient torque is investigated in this paper. The sufficient conditions of attitude stability of the spacecraft are obtained, the effect of the direction of the flexible solar arrays and some special cases are discussed. Taking the asteroids 4769 Castalia, 25143 Itokawa and the imaginary asteroids as examples, the attitude stability domains, determined by the sufficient conditions, of the spacecrafts moving on stationary orbits around them are presented. It is found that the attitude stability domains of the spacecraft with two flexible solar arrays are evidently different when the solar arrays are installed in different directions; the effect of the harmonics C 20 and C 22 of the asteroids has the significant influence on the attitude stability domains of the spacecrafts with flexible appendages moving on stationary orbits; in the certain case, the effect of the harmonics C 20 and C 22 of the asteroids has no influence on the attitude stability domains of the rigid spacecrafts moving on stationary orbits, but in the other cases, the effect of the harmonics C 20 and C 22 of the asteroids has also the significant influence on the attitude stability domains of the rigid spacecrafts moving on stationary orbits; whether the harmonics C 20 and C 22 of the asteroids are considered or not, the effect of flexible appendages decreases the attitude stability domains.

Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

5th International Conference on Emerging Ubiquitous Systems and Pervasive Networks (EUSPN) -- SEP 22-25, 2014 -- Halifax, CANADA, WOS: 000349985800002, Wireless sensor networks (WSNs) keep attracting the attention of researchers due to the newly emerging areas of application fueled by the development of inexpensive sensors and advanced communication technologies. A large group of applications - monitoring of pipelines, roads and bridges, as well as recently evolving IoT applications - specifically requires linear topology. Compared to traditional WSNs, these linear wireless sensor networks (LWSN) pose additional challenges in terms of overall delay and energy efficiency. Even though there are numerous and also very successful MAC protocols for WSN, very few of them take into consideration the specifics of linear topologies. Thus our aim is to address these challenges by proposing LINE-MAC, a MAC protocol tailored especially for LWSN. Our simulation results show that LINE-MAC achieves significant improvement in end-to-end delay, energy consumption and packet delivery ratio (PDR) compared to a general, energy and delay efficient MAC protocol for WSN. (C) 2014 The Authors. Published by Elsevier B.V.

Wireless sensor nodes become more and more attractive for a broad variety of application scenarios. Wireless Sensor Networks (WSNs) can be easily deployed and they require by design low maintenance effort. But running installations are still rare, because real world requirements and environmental conditions are even today a big challenge. Especially in multi-hop networks a minimum lifetime of several years cannot be achieved globally. In this paper, the authors present a Distributed Low Duty Cycle (DLDC) based Multi-Hop Routing (MHR) protocol for Wireless Sensor Networks guaranteeing a minimum network lifetime. The authors introduce a forecast scheme to calculate the expected life of a node with a minimal effort. The authors are convinced that by using a forecast scheme the network topology and the used protocols can be easily optimized before deploying the network. The authors evaluated their forecast scheme by measuring real sensor node parameters and simulating an example network in the Castalia simulation framework. The authors demonstrated that by using the proposed scheme an energy consumption forecast with a deviation of less than three per cent can be achieved.

In wireless body area sensor networks (WBASNs), Quality of Service (QoS) provision for patient monitoring systems in terms of time-critical deadlines, high throughput and energy efficiency is a challenging task. The periodic data from these systems generates a large number of small packets in a short time period which needs an efficient channel access mechanism. The IEEE 802.15.4 standard is recommended for low power devices and widely used for many wireless sensor networks applications. It provides a hybrid channel access mechanism at the Media Access Control (MAC) layer which plays a key role in overall successful transmission in WBASNs. There are many WBASN's MAC protocols that use this hybrid channel access mechanism in variety of sensor applications. However, these protocols are less efficient for patient monitoring systems where life critical data requires limited delay, high throughput and energy efficient communication simultaneously. To address these issues, this paper proposes a frame aggregation scheme by using the aggregated-MAC protocol data unit (A-MPDU) which works with the IEEE 802.15.4 MAC layer. To implement the scheme accurately, we develop a traffic patterns analysis mechanism to understand the requirements of the sensor nodes in patient monitoring systems, then model the channel access to find the performance gap on the basis of obtained requirements, finally propose the design based on the needs of patient monitoring systems. The mechanism is initially verified using numerical modelling and then simulation is conducted using NS2.29, Castalia 3.2 and OMNeT++. The proposed scheme provides the optimal performance considering the required QoS.

The reliability, energy efficiency, and real-time display of patient's data are important factors for Body Area Network (BAN) communication in indoor hospital environments. In this paper we propose a novel routing protocol by considering the QoS requirements of BAN data with strict reliability requirements. Our proposed algorithm increases the reliable delivery of critical BAN data at the destination We have performed extensive simulations in the OMNeT++ based simulator Castalia to demonstrate the better performance of the proposed QoS based routing protocol for reliability sensitive data in terms of successful transmission rate, lower network routing traffic (hello packets) overhead, and lower end-to-end delay (latency) in both stationary and movable patient scenarios.

In the first part of the paper, we modeled and characterized the underwater radio channel in shallow waters. In the second part, we analyze the application requirements for an underwater wireless sensor network (U-WSN) operating in the same environment and perform detailed simulations. We consider two localization applications, namely self-localization and navigation aid, and propose algorithms that work well under the specific constraints associated with U-WSN, namely low connectivity, low data rates and high packet loss probability. We propose an algorithm where the sensor nodes collaboratively estimate their unknown positions in the network using a low number of anchor nodes and distance measurements from the underwater channel. Once the network has been self-located, we consider a node estimating its position for underwater navigation communicating with neighboring nodes. We also propose a communication system and simulate the whole electromagnetic U-WSN in the Castalia simulator to evaluate the network performance, including propagation impairments (e.g., noise, interference), radio parameters (e.g., modulation scheme, bandwidth, transmit power), hardware limitations (e.g., clock drift, transmission buffer) and complete MAC and routing protocols. We also explain the changes that have to be done to Castalia in order to perform the simulations. In addition, we propose a parametric model of the communication channel that matches well with the results from the first part of this paper. Finally, we provide simulation results for some illustrative scenarios.