Single Mobile Node Research Articles

Case Report : Lymphocytic Lobulitis With Fibrocystic Disease Of The Breast

Lymphocytic lobulitis , is a fibroinflammatory benign condition of the breast which is associated with type 1 diabetes mellitus. This benign condition is uncommon and may be mistaken for inflammatory carcinoma of the breast. We report the case of a 61 year old female patient who presented with a lump in the right breast with a history of Type 2 diabetes mellitus. The lump was associated with discharge and recent onset pain. On examination a vague lump which was non mobile, involving the right breast was palpable. A single firm mobile right axillary lymph node was palpable. Peau d’orange or orange peel appearance which occurs due to blockage of sub dermal lymphatics by tumour infiltrates, was noted over the skin. Clinically the features were suggestive of inflammatory carcinoma. Mammogram suggested an inflammatory carcinoma. Ultrasound of the breast was suggestive of right duct ectasia and diffusely thickened breast with a Breast Imaging Radiology and Data System (BIRADS) score of 3. An incision biopsy was performed with histopathology confirming the lesion as lymphocytic lobulitis with fibrocystic breast disease. The patient was symptomatically managed with analgesics and reassured. She was observed on regular follow up and is currently healthy. Lymphocytic lobulitis is a rare benign lesion which mimics carcinoma. Clinically it presents with ill defined single or multiple breast lumps in young or middle aged women with thickening and hardening of skin. Magnetic Resonance Imaging better differentiates this otherwise indolent lesion from malignancies. A histopathological examination is usually confirmatory and required to alleviate concerns of patients regarding presence of a malignancy which has a much fearsome physical and psychological implication.

Artificial intelligence applications for target node positions in wireless sensor networks using single mobile anchor node

The precise location of target nodes in wireless sensor networks makes more significant even in harsh environments. However, attaining the precise location is being affected by anisotropy. Accurate position of the target node depends on connectivity, power variation, and attenuation of the signal. To minimize the effect of anisotropy conditions and improve the location accuracy, distance information and angle information of signal are fused together, extracted from Received Signal Strength (RSS) and Angle of Arrival (AoA) separately. Here, a novel concept of virtual anchor node is considered for position estimation of target node. Further, emerging application of artificial intelligence, like, Particle swarm optimization (PSO), Hybrid PSO (HPSO), and Firefly Algorithm (FA) are used separately to get the optimum positions of the target nodes. The Simulation results show that the proposed methods perform better in terms of accuracy, i.e., average error of 0.274 meters, energy, scalability, and convergence time as compared to existing techniques.

시불변/시변 환경에서의 센서 노드 배치 계획

Sensor networks are widely used in various environments, especially that that are unreachable for humans, or where long-term monitoring is required. In most of the previously reported sensor network studies, the focus was on energy consumption based on sensing range and communication strength with a large number of sensor nodes deployed a priori. Herein, we describe a sensor node placement that uses a single mobile node or small number of nodes. Initially, a small number of nodes are used under an unknown environment and hence they sparsely distributed. Based on the estimated spatial gradient at each node, extra nodes are added. For a time-varying environment, another sensor placement algorithm based on the heat conductivity theory is introduced. The intermittent sensing schedule requires an efficient node placement such that the distribution of sensor nodes enables an impartial measurement. The quantitative measure, which represents the degree of variance with respect to time, was introduced while estimating the spatial gradient. Thus, using both the algorithms accordingly will enable time-efficient and energy-efficient measurements for unknown environments.

Case Report : Lymphocytic Lobulitis With Fibrocystic Disease Of The Breast

Lymphocytic lobulitis , is a fibroinflammatory benign condition of the breast which is associated with type 1 diabetes mellitus. This benign condition is uncommon and may be mistaken for inflammatory carcinoma of the breast. We report the case of a 61 year old female patient who presented with a lump in the right breast with a history of Type 2 diabetes mellitus. The lump was associated with discharge and recent onset pain. On examination a vague lump which was non mobile, involving the right breast was palpable. A single firm mobile right axillary lymph node was palpable. Peau d’orange or orange peel appearance which occurs due to blockage of sub dermal lymphatics by tumour infiltrates, was noted over the skin. Clinically the features were suggestive of inflammatory carcinoma. Mammogram suggested an inflammatory carcinoma. Ultrasound of the breast was suggestive of right duct ectasia and diffusely thickened breast with a Breast Imaging Radiology and Data System (BIRADS) score of 3. An incision biopsy was performed with histopathology confirming the lesion as lymphocytic lobulitis with fibrocystic breast disease. The patient was symptomatically managed with analgesics and reassured. She was observed on regular follow up and is currently healthy. Lymphocytic lobulitis is a rare benign lesion which mimics carcinoma. Clinically it presents with ill defined single or multiple breast lumps in young or middle aged women with thickening and hardening of skin. Magnetic Resonance Imaging better differentiates this otherwise indolent lesion from malignancies. A histopathological examination is usually confirmatory and required to alleviate concerns of patients regarding presence of a malignancy which has a much fearsome physical and psychological implication

New path trajectory followed by Single Anchor by using Salp Swarm Algorithm in Wireless Sensor Network

In the various applications of wireless sensor networks (WSN), the event occurrence information or data sensed by the sensor node has no significance until the location of an event/sensor node is not known. Therefore, localization is an important parameter in WSN for tracking these deployed sensor nodes in the sensing area. To localize these sensor nodes, there are various existing localization models in available detailed literature. One solution to this problem is to deploy a set of static anchor nodes (GPS equipped) in the sensing area, that broadcast their coordination information to help unknown nodes to localize themselves. Another way is to use a single mobile anchor node that will follow a specific path and localize unknown nodes. But a mobile anchor node must follow an optimal path that helps to achieve high accuracy and able to localize a large number of unknown nodes in less computational time. In this paper, the author design and developed a localization algorithm in which a GPS equipped single mobile anchor node follows a new path trajectory i.e. spiral pentagon. Once the target node falls under the communication diameter of the virtual node, six virtual anchor nodes are projected in the shape of a ring around the anchor node and localize all the unknown nodes in the sensing area by using the application of Salp Swarm Algorithm (SSA) for optimization. The hypothesis of six virtual anchor nodes is to avoid the problem of Line of Sight. This proposed method assured that each target node can estimate their node coordinates at least once with a low localization error.

Obstacle-Aware Connectivity Establishment in Wireless Sensor Networks

In wireless sensor networks (WSNs), the sensor nodes collect data from the target area and send it to the base station through a multi-hop connection. As a result, high energy dissipation of the sensor node may occur. Some times failure of nodes on large scale create partitions in the network. Also, the presence of obstacles is the reason for the coverage gap in networks. The introduction of mobile nodes has been measured to be a worthy approach to significantly decrease the energy dissipation of the static sensor nodes. This job is realized by considering the route through which the mobile collectors move to collect data from the sensor nodes. Another challenging job is to find the path of the mobile collector in an area with obstacles. In this work, an obstacle aware connectivity establishment (OACE) using mobile nodes in wireless sensor networks is proposed. The mobile robot collects data from each partition and carries forward to other partitions so data finally reaches to sink. To achieve this, a Delaunay triangulation based obstacle avoidance clustering has been performed. The performance of the proposed algorithm has been shown by varying the sensor nodes to a single mobile node and multiple mobile nodes. The number of partitions in the network also plays an important role in network performance. Simulation results show that the proposed method with multiple mobile collectors is more energy-efficient with less latency as compared to the single mobile collector for data collection.

Localization Error Estimation Technique for a Randomly Deployed Mobile Sensor Node

Wireless Sensor Networks (WSNs) are network of low size and less complex devices denoted as sensor nodes that can sense the environment and communicate the recorded parameters like temperature, sound, pollution levels, humidity, speed, pressure etc. Localization is one of the fundamental requirements of WSNs. The estimation of localization error for either a stationary or mobile sensor node can be done with the help of beacons and in a two dimensional network an unknown sensor node can estimate its location if there are three or more beacon nodes in its range. If the percentage of beacons is high, it is easier to perform localization, but, the cost and energy consumption of the network also increases. To estimate the localization error of the mobile node the Gauss Newton method is implemented in this paper. The implemented method is based on a procedure in which repetition of a sequence of operations yields results successively closer to a desired result for estimation of localization error. The proposed method is based on an iterative process and thus depends on the number of rounds. For simulations, the beacon nodes are placed on the vertices of a two dimensional square field along with a random mobile node placed inside the field. The implemented method estimates localization error only for a single mobile node with respect to four beacon nodes and computes its position through multilateration by means of information transmitted from the beacon nodes. The simulations are performed on a two dimensional square field using MATLAB 7.1 and the results of the proposed method are compared with existing method to see the effectiveness.

Three-Dimensional Localization Algorithm of WSN Nodes Based on RSSI-TOA and Single Mobile Anchor Node

Aimed at the shortcomings of low localization accuracy of the fixed multianchor method, a three-dimensional localization algorithm for wireless sensor network nodes is proposed in this paper, which combines received signal strength indicator (RSSI) and time of arrival (TOA) ranging information and single mobile anchor node. A mobile anchor node was introduced in the proposed three-dimensional localization algorithm for wireless sensor networks firstly, and the mobile anchor node moves according to the Gauss–Markov three-dimensional mobility model. Then, based on the idea of using RSSI ranging in the near end and TOA ranging in the far end, a ranging method combining RSSI and TOA ranging information is proposed to obtain the precise distance between the anchor node and the unknown node. Finally, the maximum-likelihood estimation method is used to estimate the position of unknown nodes based on the obtained ranging values. The MATLAB simulation results show that the proposed algorithm had a higher localization accuracy and lower localization energy consumption compared with the traditional RSSI localization method or TOA localization method.

A new path planning strategy of a data collection problem utilising multi-mobile nodes in wireless sensor networks

The prevalent research on the path planning problem in mobile node-based data collection techniques only considers the simple situation involving a single mobile node or path endpoint located at the centre of the communication. This paper considers additional situations involving both of the above two factors and abstracts from these scenarios to formulate a hybrid optimisation problem. This optimisation problem has the characteristics of high dimensionality and a large search space. To solve this problem, the following modifications were made. First, k sub-paths based on the k-SPLITOUR algorithm were obtained. Second, a method to eliminate path intersections was designed to optimise the discrete components. Finally, a hybrid glowworm swarm optimisation (HGSO) algorithm was proposed to optimise the positions of access points along the communication circle to optimise the continuous components. The global convergence analysis of the proposed HGSO algorithm is given. Simulations and comparisons with other algorithms verified that the proposed strategy can solve the path planning problem in data collection utilising multi-mobile nodes effectively.

Optimized localization of target nodes using single mobile anchor node in wireless sensor network

In Wireless Sensor Networks (WSNs), main challenges which restrict the performance are data computation, lifetime, routing, task scheduling, security, organization and localization. Recently, numerous Computational Intelligence (CI) based potential solutions for above mentioned challenges have been proposed to fulfill the desired level of performance in WSNs. Use of CI gives autonomous and strong solutions to ascertain precise node location (2D/3D) with least hardware necessity (position finding device, i.e., GPS empowered gadget). Localization of target nodes in static scenario can be done more precisely. However, in case of mobility, determining accurate position of each node in network is a challenging problem. In this paper, a novel idea of localizing target nodes with moving single anchor node is proposed using CI based application of Particle Swarm Optimization (PSO) and H-Best Particle Swarm Optimization (HPSO). The moving anchor node is following the Hilbert trajectory. Proposed algorithms are actualized for range-based, distributed, non-collaborative and isotropic WSNs. Only single moving anchor node is used as a reference node to localize the target nodes in the entire network. In proposed algorithms, problem of Line of Sight (LoS) is minimized due to projection of virtual anchor nodes.

Retraction Note to: Improved fast handover method for multiple node by using mobile nodes guide

The fast mobile internet protocol version 6 (FMIPv6) was suggested as a fast handover mechanism over the mobile wireless Internets in order to reduce the handover latency of a mobile node (MN). However, FMIPv6 was originally designed to deal with single MN’s. In mobile wireless Internet, a multiple MNs may do a handover at the same time as a consequence of its movement from one network to another new one. This will therefore lead to the bandwidth waste and low handover performance. This paper intends to propose a multiple handover-based mobile node (MHB-MN) control method and an enhanced FMIPv6 mechanism in order to resolve the abovementioned problem. The proposal of such an MHB-MN method aims at having one mobile node work as a guide for a group of neighboring MNs. This means that the guide of MN prepares itself for a handover before actually taking the initial steps of the actual handover operation. Based on obtained results, it is plainly observable that by MHB-MN method, the handover initiation time, handover latency and handover control messages can be reduced compared to those of FMIPv6. Furthermore, the contention of the wireless channel for multiple MNs can be improved by the use of fewer control messages. Finally, the paper introduces an analytical model to show that by enabling the MHB-MN method and enhancing the FMIPv6 method, a multiple of nodes can perform rapid handover processes with low handover latency compared to that of the FMIPv6 technique.

RETRACTED ARTICLE: Improved fast handover method for multiple node by using mobile nodes guide

The fast mobile internet protocol version 6 (FMIPv6) was suggested as a fast handover mechanism over the mobile wireless Internets in order to reduce the handover latency of a mobile node (MN). However, FMIPv6 was originally designed to deal with single MN's. In mobile wireless Internet, a multiple MNs may do a handover at the same time as a consequence of its movement from one network to another new one. This will therefore lead to the bandwidth waste and low handover performance. This paper intends to propose a multiple handover-based mobile node (MHB-MN) control method and an enhanced FMIPv6 mechanism in order to resolve the abovementioned problem. The proposal of such an MHB-MN method aims at having one mobile node work as a guide for a group of neighboring MNs. This means that the guide of MN prepares itself for a handover before actually taking the initial steps of the actual handover operation. Based on obtained results, it is plainly observable that by MHB-MN method, the handover initiation time, handover latency and handover control messages can be reduced compared to those of FMIPv6. Furthermore, the contention of the wireless channel for multiple MNs can be improved by the use of fewer control messages. Finally, the paper introduces an analytical model to show that by enabling the MHB-MN method and enhancing the FMIPv6 method, a multiple of nodes can perform rapid handover processes with low handover latency compared to that of the FMIPv6 technique.

Lightweight Handover Control Function (L-HCF) for Mobile Internet Protocol version Six (IPv6)

While shifting from one specific single access point to another point, the Mobile IP address permits a single mobile node for keeping an uninterrupted connection with the internet. Nevertheless, when handover occurs, the packets designed for the mobile nodes may have some delay or the risk of getting lost, because of the operations such as Mobile IP handover and link switching delay. This paper presented a novel control function that is called Lightweight Handover Control Function (L-HCF). The purpose of this control function is to improve of the handover performance in the perspective of Mobile IPv6 over wireless networks. The L-HCF functionality allows a router to choose which Access Router(AR)/Access Point (AP)/ address that the mobile node is associated with when movement is needed, by using available IP addresses in its database if the movement operation in side domain or by exchange messages between other routers if the movement alter domain. Thus the Mobile Nodes (MN) can use this address without engaging in the process of Stateless Address Auto-configuration or the procedure of Duplicate Address Detection. The function is implemented analytically then simulated in OPNET. The result shows that, the control function offer minimum latency, less packet loss compared with the standard function of the mobile IPv6.

Enhanced Fast Handover for Network Mobility in Intelligent Transportation Systems

To maintain the Internet connectivity of a group of nodes in intelligent transportation systems (ITSs), the network mobility basic support (NEMO BS) protocol was standardized. The NEMO BS provides mobility for mobile network nodes (MNNs) in a moving network through a mobile router (MR). Since packet loss in NEMO dramatically increases during a handover as the number of MNNs increases, Mobile IPv6 fast handovers (FMIPv6) was adopted to reduce packet loss and handover latency. However, since FMIPv6 was originally designed for a single mobile node (MN), FMIPv6 based on NEMO (fNEMO) incurs a high tunneling burden on the link between the previous and new access routers (PAR and NAR, respectively). In this paper, we propose an enhanced fNEMO (EfNEMO) as an efficient fast handover scheme that significantly mitigates the tunneling burden and handover latency. In particular, EfNEMO performs a tentative binding update (BU) procedure to register a new care-of address (NCoA) for the MR with the MR's home agent (HA) before the layer-2 handover. Consequently, EfNEMO delivers packets destined for MNNs via various paths between the HA and the NAR without any tunneling. Furthermore, EfNEMO reduces handover latency because it performs the registration to the HA in advance. By establishing an analytical model for the proposed EfNEMO, we investigate the handover performance of NEMO, fNEMO, and EfNEMO. In addition, we compare EfNEMO with NEMO and fNEMO in terms of the overall cost and the handover latency. Simulation is also performed to compare in a more realistic environment. The results of analysis and simulation show that EfNEMO significantly outperforms fNEMO and NEMO.

A Navigation Method for Multiple Robots Based on a Single Mobile Node

To satisfy the requirements of independent navigation in low cost multiple robots, a navigation frame of masterslave robots with only one master robot is introduced briefly. A range-only navigation algorithm for slave robots of low cost is presented for the navigation in unknown current. This algorithm only needs a master robot. The master is just a single mobile node which has high navigation performance. Observability of this master-salve system is theoretically analyzed. The conditions of slave robot trajectory under which observability is guaranteed are evaluated by a slave robot in real-time. The slave takes appropriate action to control its heading to achieve observability if observability is lost on the current trajectory. The navigation algorithm is implemented by a standard extended Kalman filter, and it is able to acquire accurate estimation of robot's position. The simulation results show its effectiveness of the proposed algorithm.

Utilizing detours for energy conservation in mobile wireless networks

Autonomous robotic systems have been gaining the attention of research community in mobile ad hoc network since the past few years. While motion cost and communications cost constitute the primary energy consumers, each of them is investigated independently. By taking into account the power consumption of both entities, the overall energy efficiency of a system can be further improved. In this paper, the energy optimization problem of radio communication and motion is examined. We consider a hybrid wireless network in two scenarios: first, a single autonomous mobile node communicating with multiple static relays through single hop, and secondly, a single mobile node communicating with a static base station via a mobile relay. The mobile node interacts with the relays within its vicinity by continuously transmitting high-bandwidth data, e.g. triggered by a multimedia application like video surveillance. The goal is to find the best paths such that the energy consumption for both mobility and communications is minimized for all mobile nodes. We introduce Radio-Energy-Aware (REA) path computation strategy by utilizing node mobility. Given the starting point, the target point and the position of the relays, our simulation results show that the proposed strategy improves the energy efficiency of mobile node compared to Motion-Energy-Aware (MEA) path constructed based only on the mobility cost.

Purposeful mobility for relaying and surveillance in mobile ad hoc sensor networks

We consider a mobile ad hoc sensor network. The mobility of the sensor nodes is designed with the cost of communication and mobility in mind along with consideration of the possible scanning tasks of the nodes. Our mobility algorithm is developed in the context of a distributed system where, for any single mobile node, only local information about associated energy costs is known. We use a distributed simulated annealing framework to govern the motion of the nodes and prove that, in a limiting sense, a global objective function comprising mobility and communication energy costs are minimized. This paper concludes with a simulation study focusing on mobile sensors with dual roles of scanning and relaying higher priority tracking traffic from tracking nodes.