RF Propagation Analysis of MICAz Motes Antenna with Ground Effect

In this paper we analyzed the Radio Frequency (RF) propagation characteristics of monopole antenna in MICAz mote. During the experimental analysis, two scenarios are considered. In Scenario-I, a pair of MICAz nodes (one transmitting and one receiving node) are placed on the ground and the RSSI is measured in presence of the ground effect. In Scenario-II, only the transmitting node is placed above the ground; however, the receiving node is placed on the ground. The RSSI is measured by changing the antenna orientation at different angles and distances between them. The results show that the ground effect, antenna orientation and distance between the sensor nodes drastically affect the RSSI.Comment: 15th IEEE International Multi Topic Conference (INMIC12), 201

Modeling and Evaluating Enhancements in Expanding Ring Search Algorithm for Wireless Reactive Protocols

In case of high dynamic topology, reactive routing protocols provide quick convergence by faster route discoveries and route maintenance. Frequent roadcasts reduce routing efficiency in terms of broadcast cost; Bk, and expected time cost; E[t]. These costs are optimized using different mechanisms. So, we select three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR), and DYnamic Manet On-demad (DYMO). We model expanding Ring Search (ERS); an optimization mechanism in the selected protocols to reduce Bk and E[t]. A novel contribution of this work is enhancement of default ERS in the protocols to optimize Bk and E[t]. Using NS-2, we evaluate and compare default-ERS used by these protocols; AODV-ERS1, DSR-ERS1 and DYMO-ERS1 with enhanced-ERS; AODVERS2, DSR-ERS2 and DYMO-ERS2. From modeling and analytical comparison, we deduce that by adjusting Time-To-Live (T TL) value of a network, efficient optimizations of Bk and E[t] can be achieved.Comment: 25th IEEE CCECE, 2012, Montreal Canad

Combined Human, Antenna Orientation in Elevation Direction and Ground Effect on RSSI in Wireless Sensor Networks

In this paper, we experimentally investigate the combined effect of human, antenna orientation in elevation direction and the ground effect on the Received Signal Strength Indicator (RSSI) parameter in the Wireless Sensor Network (WSN). In experiment, we use MICAz motes and consider different scenarios where antenna of the transmitter node is tilted in elevation direction. The motes were placed on the ground to take into account the ground effect on the RSSI. The effect of one, two and four persons on the RSSI is recorded. For one and two persons, different walking paces e.g. slow, medium and fast pace, are analysed. However, in case of four persons, random movement is carried out between the pair of motes. The experimental results show that some antenna orientation angles have drastic effect on the RSSI, even without any human activity. The fluctuation count and range of RSSI in different scenarios with same walking pace are completely different. Therefore, an efficient human activity algorithm is need that effectively takes into count the antenna elevation and other parameters to accurately detect the human activity in the WSN deployment region.Comment: 10th IEEE International Conference on Frontiers of Information Technology (FIT 12), 201

An energy scaled and expanded vector-based forwarding scheme for industrial underwater acoustic sensor networks with sink mobility

Industrial Underwater Acoustic Sensor Networks (IUASNs) come with intrinsic challenges like long propagation delay, small bandwidth, large energy consumption, three-dimensional deployment, and high deployment and battery replacement cost. Any routing strategy proposed for IUASN must take into account these constraints. The vector based forwarding schemes in literature forward data packets to sink using holding time and location information of the sender, forwarder, and sink nodes. Holding time suppresses data broadcasts; however, it fails to keep energy and delay fairness in the network. To achieve this, we propose an Energy Scaled and Expanded Vector-Based Forwarding (ESEVBF) scheme. ESEVBF uses the residual energy of the node to scale and vector pipeline distance ratio to expand the holding time. Resulting scaled and expanded holding time of all forwarding nodes has a significant difference to avoid multiple forwarding, which reduces energy consumption and energy balancing in the network. If a node has a minimum holding time among its neighbors, it shrinks the holding time and quickly forwards the data packets upstream. The performance of ESEVBF is analyzed through in network scenario with and without node mobility to ensure its effectiveness. Simulation results show that ESEVBF has low energy consumption, reduces forwarded data copies, and less end-to-end delay

Analysis and Modeling Experiment Performance Parameters of Routing Protocols in MANETs and VANETs

In this paper, a framework for experimental parameters in which Packet Delivery Ratio (PDR), effect of link duration over End-to-End Delay (E2ED) and Normalized Routing Overhead (NRO) in terms of control packets is analyzed and modeled for Mobile Ad-Hoc NETworks (MANETs) and Vehicular Ad-Hoc NETworks (VANETs) with the assumption that nodes (vehicles) are sparsely moving in two different road. Moreover, this paper contributes the performance comparison of one Proactive Routing Protocol; Destination Sequenced Distance vector (DSDV) and two reactive protocols; DYnamic Source Routing (DSR) and DYnamic MANET On-Demand (DYMO). A novel contribution of this work is enhancements in default versions of selected routing protocols. Three performance parameters; PDR, E2ED and NRO with varying scalabilities are measured to analyze the performance of selected routing protocols with their original and enhanced versions. From extensive simulations, it is observed that DSR outperforms among all three protocols at the cost of delay. NS-2 simulator is used for simulation with TwoRayGround propagation model to evaluate analytical results

Variants and variations among gullian barre syndrome presenting as acute flaccid paralysis

Acute flaccid paralysis (AFP) is a clinical syndrome characterized by rapid onset of weakness that frequently includes respiratory and bulbar weakness. An accurate and early diagnosis of the cause has important bearing on the management and prognosis. Guillian Barre Syndrome (GBS) is a post infectious polyradiculoneuropathy involving mainly motor but sometimes sensory and autonomic nerves