In this study we have examined a plane wave diffraction problem by a finite plate having different impedance boundaries. The Fourier transforms were used to reduce the governing problem into simultaneous Wiener-Hopf equations which are then solved using the standard Wiener-Hopf procedure. Afterwards the separated and interacted fields were developed asymptotically by using inverse Fourier transform and the modified stationary phase method. Detailed graphical analysis was also made for various physical parameters we were interested in.

The diffraction of a spherical acoustic wave generated by a point source from impedance slit in a moving fluid is investigated. The diffracted wave is calculated in the far field regime as a sum of fields produced by the edges of the slit and an incident field. The Myers’ impedance conditions are assumed along the edges of the slit. Such conditions are well adopted for the boundaries of the impedance barriers and yield reliable predictions of the diffraction patterns. A Wiener–Hopf technique is invoked to resolve the problem in combination with Fourier transform techniques and asymptotic analysis. The appositeness of the results and the effect of pertinent physical parameters on the separated field are presented and analyzed graphically.

Aim of this study is analyzing energy conservation which is one of the most vital aspects in Wireless Sensor Networks (WSNs) for better network durability, since sensor nodes have limited resources of energy. In our propose technique, we have shown that how in presence of existing Error Control Coding (ECC) techniques and decoder complexity energy efficiency increased. That is by estimating transmitter power for each sensor node in given environment. Since adoption of ECC reduces required transmitter power for reliable communication, while increase processing energy of decoding operations. Required transmitter power for sensor nodes in given environment for different coding techniques like Reed-Solomon (RS), Convolutional (CC) energy efficiency and bit error rate has been analyzed for different Eb/N0.

As sensor nodes are deployed anywhere in a wireless sensor network, hence their communication can be easily monitored. In these networks, message protection and node identification are very issues. Hence, security of large scale such networks requires efficient key distribution and management mechanisms. Quantum cryptography and particularly quantum key distribution is such a technique that allocates secure keys only for short distances. While not completely secure, it offers huge advantages over traditional methods by the use of entanglement swapping and quantum teleportation. Reversible logic gates like CNOT, Toffoli, Fredkin etc. are of basic importance in Quantum Computing. In our research, we adopted a EPR-pair allocation scheme in terms of these quantum gates to overcome the susceptibility caused by malicious nodes. As the qubits stored in a sensor node can be used only once and cannot be duplicated, hence risk of information leakage reduced even if the node are compromised.

In this paper, we propose the mobility of a sink in improved energy efficient PEGASIS-based protocol (IEEPB) to advance the network lifetime of Wireless Sensor Networks (WSNs). The multi-head chain, multi-chain concept and the sink mobility affects largely in enhancing the network lifetime of wireless sensors. Thus, we recommend Mobile sink improved energy-efficient PEGASIS-based routing protocol (MIEEPB); a multi-chain model having a sink mobility, to achieve proficient energy utilization of wireless sensors. As the motorized movement of mobile sink is steered by petrol or current, there is a need to confine this movement within boundaries and the trajectory of mobile sink should be fixed. In our technique, the mobile sink moves along its trajectory and stays for a sojourn time at sojourn location to guarantee complete data collection. We develop an algorithm for trajectory of mobile sink. We ultimately perform wide-ranging experiments to assess the performance of the proposed method. The results reveal that the proposed way out is nearly optimal and also better than IEEPB in terms of network lifetime.

This paper deals with the routing protocols for distributed wireless sensor networks. The conventional protocols for WSNs like Low Energy adaptive Clustering Hierarchy (LEACH), Stable Election Protocol (SEP), Threshold Sensitive Energy Efficient Network (TEEN), Distributed Energy Efficient Clustering Protocol (DEEC) may not be optimal. We propose a scheme called Away Cluster Head (ACH) which effectively increases the efficiency of conventional clustering based protocols in terms of stability period and number of packets sent to base station (BS). We have implemented ACH scheme on LEACH, SEP, TEEN and DEEC. Simulation results show that LEACH-ACH, SEP-ACH, TEEN-ACH and DEEC-ACH performs better than LEACH, SEP, TEEN and DEEC respectively in terms of stability period and number of packets sent to BS. The stability period of the existing protocols prolongs by implementing ACH on them.

With increase in ageing population, health care market keeps growing. There is a need for monitoring of health issues. Wireless Body Area Network (WBAN) consists of wireless sensors attached on or inside human body for monitoring vital health related problems e.g, Electro Cardiogram (ECG), Electro Encephalogram (EEG), ElectronyStagmography (ENG) etc. Due to life threatening situations, timely sending of data is essential. For data to reach health care center, there must be a proper way of sending data through reliable connection and with minimum delay. In this paper transmission delay of different paths, through which data is sent from sensor to health care center over heterogeneous multi-hop wireless channel is analyzed. Data of medical related diseases is sent through three different paths. In all three paths, data from sensors first reaches ZigBee, which is the common link in all three paths. Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunication System (UMTS) are connected with ZigBee. Each network (WLAN, WiMAX, UMTS) is setup according to environmental conditions, suitability of device and availability of structure for that device. Data from these networks is sent to IP-Cloud, which is further connected to health care center. Delay of data reaching each device is calculated and represented graphically. Main aim of this paper is to calculate delay of each link in each path over multi-hop wireless channel.

This paper presents comparison of Access Techniques used in Medium Access Control (MAC) protocol for Wireless Body Area Networks (WBANs). Comparison is performed between Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), Pure ALOHA and Slotted ALOHA (S-ALOHA). Performance metrics used for comparison are Throughput (T), Delay (D) and Offered Load (G). The main goal for comparison is to show which technique gives highest Throughput and lowest Delay with increase in Load. Energy efficiency is major issue in WBAN that is why there is need to know which technique performs best for energy conservation and also gives minimum delay. Simulations are performed for different scenarios and results are compared for all techniques. We suggest TDMA as best technique to be used in MAC protocol for WBANs due to its high throughput and minimum delay with increase in load. MATLAB is the tool that is used for simulation.

Reduced energy consumption in sensor nodes is one of the major challenges in Wireless Sensor Networks (WSNs) deployment. In this regard, Error Control Coding (ECC) is one of techniques used for energy optimization in WSNs. Similarly, critical distance is another term being used for energy efficiency, when used with ECC provides better results of energy saving. In this paper three different critical distance values are used against different coding gains for sake of energy saving. If distance lies below critical distance values then particular encoders are selected with respect to their particular coding gains. Coding gains are used for critical distances estimation of all encoders. This adaptive encoder and transmit power selection scheme with respect to their coding gain results in a significant energy saving in WSNs environment. Simulations provide better results of energy saving achieved by using this adaptive scheme.

Wireless Sensor Networks (WSNs) are comprised of thousands of sensor nodes, with restricted energy, that co-operate to accomplish a sensing task. Various routing Protocols are designed for transmission in WSNs. In this paper, we proposed a hybrid routing protocol: Zonal-Stable Election Protocol (Z-SEP) for heterogeneous WSNs. In this protocol, some nodes transmit data directly to base station while some use clustering technique to send data to base station as in SEP. We implemented Z-SEP and compared it with traditional Low Energy adaptive clustering hierarchy (LEACH) and SEP. Simulation results showed that Z-SEP enhanced the stability period and throughput than existing protocols like LEACH and SEP.

Cluster based Wireless Sensor Networks (WSNs) have been widely used for better performance in terms of energy efficiency. Efficient use of energy is challenging task of designing these protocols. Energy holedare created due to quickly drain the energy of a few nodes due to non-uniform distribution in the network. Normally, energy holes make the data routing failure when nodes transmit data back to the base station. We proposedEnergy-efficient HOleRemoving Mechanism (E-HORM) technique to remove energy holes. In this technique, we use sleep and awake mechanism for sensor nodes to save energy. This approach finds the maximum distance node to calculate the maximum energy for data transmission. We considered it as a threshold energy Eth. Every node first checks its energy level for data transmission. If the energy level is less than Eth, it cannot transmit data. We also explain mathematically the energy consumption and average energy saving of sensor nodes in each round. Extensive simulations showed that when use this approach for WSNs significantly helps to extend the network lifetime and stability period.

In Wireless Multi-hop Networks (WMhNs), routing protocols with energy efficient and delay reduction techniques are needed to fulfill users' demands. In this paper, we present Linear Programming models (LP_models) to assess and enhance reactive routing protocols. To practically examine constraints of respective LP_models over reactive protocols, we select AODV, DSR and DYMO. It is deduced from analytical simulations of LP models in MATLAB that quick route repair reduces routing latency and optimizations of retransmission attempts results efficient energy utilization. To provide quick repair, we enhance AODV and DSR. To practically examine the efficiency of enhanced protocols in different scenarios of WMhNs, we conduct simulations using NS-2. From simulation results, enhanced DSR and AODV achieve efficient output by optimizing routing latencies and routing load in terms of retransmission attempts.

Energy efficient routing protocols are consistently cited as efficient solutions for Wireless Sensor Networks (WSNs) routing. The area of WSNs is one of the emerging and fast growing fields which brought low cost, low power and multi-functional sensor nodes. In this paper, we examine some protocols related to homogeneous and heterogeneous networks. To evaluate the efficiency of different clustering schemes, we compare five clustering routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient Sensor Network (TEEN), Distributed Energy Efficient Clustering (DEEC) and two variants of TEEN which are Clustering and Multi-Hop Protocol in Threshold Sensitive Energy Efficient Sensor Network (CAMPTEEN) and Hierarchical Threshold Sensitive Energy Efficient Sensor Network (H-TEEN). The contribution of this paper is to introduce sink mobility to increase the network life time of hierarchal routing protocols. Two scenarios are discussed to compare the performances of routing protocols; in first scenario static sink is implanted and in later one mobile sink is used. We perform analytical simulations in MATLAB by using different performance metrics such as, number of alive nodes, number of dead nodes and throughput.

The clustering algorithm are considered as a kind of key technique used to reduce energy consumption. It can help in increasing the stability period and network life time. Routing protocol for efficient energy utilization should be designed for heterogeneous Wireless Sensor Networks (WSNs). We purpose Hybrid-DEEC (H-DEEC), a chain and cluster based (hybrid) distributed scheme for efficient energy utilization in WSNs. In H-DEEC,elected Cluster Heads (CHs) communicate the Base Station (BS) through beta elected nodes, by using multi-hopping. We logically divide the network into two parts, on the basis of the residual energy of nodes. The normal nodes with high initial and residual energy will behighlyprobable to be CHs than the nodes with lesser energy. To overcome the deficiencies of H-DEEC, we propose Multi-Edged Hybrid-DEEC (MH-DEEC). In MH-DEEC the criteria of chain construction is modified. Finally, the comparison in simulation results with other heterogeneous protocols show that, MH-DEEC and H-DEEC achieves longer stability time and network life time due to efficient energy utilization.

Frequent topological changes due to high mobility is one of the main issues in Vehicular Ad-hoc NETworks (VANETs). In this paper, we model transmission probabilities of 802.11p for VANETs and effect of these probabilities on average transmission time. To evaluate the effect of these probabilities of VANETs in routing protocols, we select Dynamic Source Routing (DSR), Fish-eye State Routing (FSR) and Optimized Link State Routing (OLSR). Framework of these protocols with respect to their packet cost is also presented in this work. A novel contribution of this work is enhancement of chosen protocols to obtain efficient behavior. Extensive simulation work is done to prove and compare the efficiency in terms of high throughput of enhanced versions with default versions of protocols in NS-2. For this comparison, we choose three performance metrics; throughput, End-to-End Delay (E2ED) and Normalized Routing Load (NRL) in different mobilities and scalabilities. Finally, we deduce that enhanced DSR (DSR-mod) outperforms other protocols by achieving 16% more packet delivery for all scalabilities and 28% more throughput in selected mobilities than original version of DSR (DSR-orig).

In this paper, we have modeled the routing overhead generated by three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET On-deman (DYMO). Routing performed by reactive protocols consists of two phases;route discovery and route maintenance. Total cost paid by a protocol for efficient routing is sum of the cost paid in the form of energy consumed and time spent. These protocols majorly focus on the optimization performed by expanding ring search algorithm to control the flooding generated by the mechanism of blind flooding. So, we have modeled the energy consumed and time spent per packet both for route discovery and route maintenance. The proposed framework is evaluated in NS-2 to compare performance of the chosen routing protocols.

Being most popular and IETF standard metric, minimum hop count is appropriately used by ad hoc networks, as new paths must rapidly be found in the situations where quality paths could not be found in due time due to high node mobility. There always has been a tradeoff between throughput and energy consumption, but stationary topology of WMNs and high node density of WSN's benefit the algorithms to consider quality-aware routing to choose the best routes. In this paper, we analytically review ongoing research on wireless routing metrics which are based on ETX (expected transmission count) as it performs better than minimum hop count under link availability. Performances over ETX, target platforms and design requirements of these ETX based metrics are high-lighted. Consequences of the criteria being adopted (in addition to expected link layer transmissions & retransmissions) in the form of incremental: (1) performance overheads and computational complexity causing inefficient use of network resources and instability of the routing algorithm, (2) throughput gains achieved with better utilization of wireless medium resources have been elaborated.

Flooding is a fundamental and effective data dissemination mechanism for route discovery, address resolution and many other network services in MANET, cause redundant rebroadcasts, which in result leads to the broadcast storm problem. Although many approaches have been proposed to solve the broadcast storm problem, none have been regarded as the satisfying solution. In this paper, we propose a distance-based dynamically adjusted probabilistic forwarding scheme and compare it with simple flooding and fixed probabilistic schemes. Our approach dynamically adjusts the rebroadcast probability according to the distance from the sender. The adaption is based only on distance without the assistance of neighbor knowledge. The proposed scheme keeps up the reachability of blind flooding while maintaining the simplicity of probability based schemes.