Bandwidth Estimation in Network Probing Techniques Utilizing Min-Plus Algebraic Methods
Diagnosis of Anemia using Non-Invasive Anemia Detector through Parametrical Analysis
The Effectiveness of Jaya Optimization for Energy Aware Cluster Based Routing in Wireless Sensor Networks
Stress Analysis and Detection from Wearable Devices
Intrusion-Tolerant Sink Configuration: A Key to Prolonged Lifetime in Wireless Sensor Networks
Channel Estimation and It’s Techniques: A Survey
Impact of Mobility on Power Consumption in RPL
Implementation of Traffic Engineering Technique in MPLS Network using RSVP
FER Performance Analysis of Adaptive MIMO with OSTBC for Wireless Communication by QPSK Modulation Technique
Performance Evaluation of Advanced Congestion Control Mechanisms for COAP
DGS Based MIMO Microstrip Antenna for Wireless Applications
A Review on Optimized FFT/IFFT Architectures for OFDM Systems
Balanced Unequal Clustering AlgorithmFor Wireless Sensor Network
HHT and DWT Based MIMO-OFDM for Various ModulationSchemes: A Comparative Approach
Study and Comparison of Distributed Energy Efficient Clustering Protocols in Wireless Sensor Network: A Review
Diagnosis of Anemia using Non-Invasive Anemia Detector through Parametrical Analysis
Multiple Input Multiple Output (MIMO) technology has important role in wireless communication systems; because it offers significant increase in data rate and link range without additional transmit power. The conventional MIMO uses 2 to 4 antennas per terminal. In order to achieve high spectral efficiency, the concept of large –MIMO is emerging. The implementation of large-MIMO undergoes complex process at receiver end in estimation and detection. The several aspects of wireless communication based feedback with multiple antennas, such as the estimation of the Channel State Information (CSI), the quantization of the CSI with a finite number of bits to enable its feedback and effect of errors in the feedback channel on the performance of the communication system are need to be considered. In this paper, the Ergodic Channel capacity calculations for large-MIMO are presented. The Bit Error Rate (BER) analysis is carried out for different modulation techniques using OFDM for the case of Multiple Input Single Output (MISO) systems using beam forming technique and for the Single Input Multiple Output (SIMO) system using Maximal Ratio Combining (MRC) technique.
Energy in Wireless Sensor Networks (WSNs) is quite limited. Since sensor nodes are usually much dense, data sampled by sensor nodes have much redundancy, data aggregation becomes an effective method to eliminate redundancy, minimize the number of transmission, and then to save energy. Many applications can be deployed in WSNs and various sensors are embedded in nodes, the packets generated by heterogeneous sensors or different applications have different attributes. The packets from different applications cannot be aggregated. Otherwise, most data aggregation schemes employ static routing protocols, which cannot dynamically or intentionally forward packets according to network state or packet types. The spatial isolation caused by static routing protocol is unfavourable to data aggregation. To make data aggregation more efficient, in this paper, the authors introduce the concept of packet attribute, and then propose an Attribute-aware Data Aggregation (ADA) scheme consisting of a packet-driven timing algorithm and a special dynamic routing protocol. Inspired by the concept of potential in physics and pheromone in ant colony, a potential-based dynamic routing is elaborated to support an ADA strategy.
Advances in Wireless Sensor Network technology have enabled small and low-cost sensors with the capability of sensing various types of physical and environmental conditions, data processing, and wireless communication. In the Wireless Sensor Network (WSN), the sensor nodes have a limited transmission range and their processing and storage capabilities as well as their energy resources are limited. An efficient and secure routing protocol for Wireless Sensor Networks through SNR-based dynamic clustering mechanisms can partition the nodes into clusters and select the Cluster Head (CH) among the nodes based on the energy, and non CH nodes join with a specific CH based on the SNR values. The clustering technique is effective in prolonging the lifetime of the WSN [3]. Single cluster head in a cluster-based replication to improve the energy consumption rate, such as clustering, efficient routing, and data aggregation using Single Clustering head is used. The simulation result demonstrates that the dual cluster heads in distributed hash table replication can improve the performances of a replica manager with respect to updates propagation in comparison to that of a single cluster head in distributed hash table replication system. The authors assume that replicas refer to identical copies of a file and replica managers are those mobile nodes that hold one or multiple replicas. Replica managers accept query requests from other mobile nodes and reply with the requested files.
One of the important issues of WSN (Wireless Sensor Network) is efficient utilization of limited energy resources in the battery operated sensor node. Clustering provides an efficient method for utilizing the energy efficiently and balancing the energy consumption among the sensor nodes in the networks. Existing clustering algorithms select the Cluster Head with a high residual energy and rotate the Cluster Heads at regular intervals to distribute the energy consumption among the nodes .The responsibility of Cluster Head is to gather the data from the Cluster Members and then forwarding them to the BS. It spends more energy for rotating the Cluster Head at regular interval and gathering the data from the Cluster Members. However, the energy hole problem and imbalance of energy consumptions among the nodes are not avoided in clustering. To mitigate the energy hole problem and utilize the energy efficiently, the authors have proposed a Balanced Unequal Clustering Algorithm. The simulation results prove that our algorithm is more efficient and achieves more energy savings than LEACH and HEED.
Quorum-based Power-Saving (QPS) protocols have been proposed for ad hoc networks (e.g., IEEE 802.11 ad hoc mode) to increase energy efficiency and prolong the operational time of mobile stations. These protocols assign to each station a cycle pattern that specifies when the station should wake up (to transmit/receive data) and sleep (to save battery power). In all existing QPS protocols, the cycle length is either identical for all stations or is restricted to certain numbers (e.g., squares or primes). These restrictions on cycle length severely limit the practical use of QPS protocols as each individual station may want to select a cycle length that is best suited for its own need (in terms of remaining battery power, tolerable packet delay, and drop ratio). In this paper, the authors have proposed the notion of Hyper Quorum System (HQS)—a generalization of QPS that allows for arbitrary cycle lengths. We describe algorithms to generate two different classes of HQS given any set of arbitrary cycle lengths as input. They have also described how to find the optimal cycle length for a station to maximize energy efficiency, subject to certain performance constraints. Then they have presented analytical and simulation results that show the benefits of HQS-based power-saving protocols over the existing QPS protocols. The HQS protocols yield up to 41% improvement in energy efficiency under heavy traffic loads while eliminating more than 90% delay drops under light traffic loads.
Data-gathering Wireless Sensor Networks (WSNs) are operated unattended over long time horizons to collect data in several applications. Typically, sensors have limited energy (e.g., an on-board battery) and are subject to the elements in the terrain. In network operations, which largely involve periodically changing network flow decisions to prolong the network lifetime, are managed remotely, and the collected data are retrieved by a user via internet. An integrated topology control and routing problem in cluster-based WSNs are analyzed to improve the network lifetime. To prolong network lifetime via efficient use of the limited energy at the sensors , a hierarchical network structure with multiple sinks at which the data collected by the sensors are gathered through the cluster heads are adopted . A Mixed Integer Linear Programming (MILP) model to optimally determine the sink and CH locations as well as the data flow in the network is considered. This model effectively utilizes both the position and the energy-level aspects of the sensors while selecting the CHs and avoids the highest-energy sensors. For the solution of the MILP model, an effective Benders Decomposition (BD) approach that incorporates an upper bound heuristic algorithm is used.