MANET Routing protocols

Radio frequency (RF) energy transfer and harvesting techniques have recently become alternative methods to power the next generation wireless networks. As this emerging technology enables proactive energy replenishment of wireless devices, it is advantageous in supporting applications with quality of service (QoS) requirements. In this paper, we present an extensive literature review on the research progresses in wireless networks with RF energy harvesting capability, referred to as
RF energy harvesting networks (RF-EHNs). First, we present
an overview of the RF-EHNs including system architecture, RF
energy harvesting techniques and existing applications. Then, we present the background in circuit design as well as the state-of-the-art circuitry implementations, and review the communication protocols specially designed for RF-EHNs. We also explore various key design issues in the development of RF-EHNs according to the network types, i.e., single-hop networks, multi-antenna networks, relay networks, and cognitive radio networks. Finally, we envision some open research directions.

Wireless mobile ad-hoc networks are characterized as networks without any physical connections. In these networks there is no fixed topology due to the mobility of nodes, interference, mulitpath propagation and path loss. Hence a dynamic routing protocol is needed for these networks to function properly. Many Routing protocols have been developed for accomplishing this task. The purpose of this master thesis is to study, understand, analyze and discuss two mobile ad-hoc routing protocols DSDV and AODV where the first one is a proactive protocol depending on routing tables which are maintained at each node. The other one is a reactive protocol, which find a route to a destination on demand, whenever communication is needed. Considering the bandwidth, throughput and packet loss, in both DSDV and AODV routing protocols, DSDV is best suited for only smaller networks and AODV is suited for general Ad-hoc networks.

Routing protocols in wireless sensor networks (WSN) have been substantially investigated by researches. Most state-of-the-art surveys have focused on reviewing the different routing schemes that have been proposed for WSN and classifying them based on the network's type and protocol's operation. Security aspects in routing protocols have not been given enough attention, since most of the routing protocols in WSNs have not been designed with security requirements in mind. However, taking into consideration that WSN applications need to support critical infrastructures (i.e., military, healthcare, environmental, etc.), security becomes an issue. And since these infrastructures are highly depended on the availability of resources, focus has especially been given to support a secure, resilient and reliable environment, with multipath routing being one of the added functionalities. The need for security in sensitive WSN application has lead researchers to design secure multipath routing protocols from the beginning or design security extensions for existing protocols. This paper surveys the current state-of-the-art of secure multipath routing protocols in WSNs, classifies the protocols in categories according to their security-related operational objectives, defines a new threat model in the routing procedure and identifies open research issues in the area.

The Efficient routing protocols can provide significant benefits to mobile ad hoc networks, in terms of both performance and reliability. Many routing protocols for such networks have been proposed so far. Amongst the most popular ones are Ad hoc On-demand Distance Vector (AODV), Destination-Sequenced Distance-Vector Routing protocol (DSDV), Dynamic Source Routing Protocol (DSR), and Optimum Link State Routing (OLSR). Despite the popularity of those protocols, research efforts have not focused much in evaluating their performance when applied to variable bit rate (VBR). In this paper we present our observations regarding the performance comparison of the above protocols for VBR in mobile ad hoc networks (MANETs). We perform extensive simulations, using NS-2 simulator. Our studies have shown that reactive protocols perform better than proactive protocols. Further DSR has performed well for the performance parameters namely delivery ratio and routing overload while AODV performed better in terms of average delay.

The fundamental characteristic which differentiates MANETs from other wireless or wired networks is mobility. Therefore, MANET routing protocols are designed to adaptively cater for dynamic changes in topology while maximizing throughput and packet delivery ratio, and minimizing delay, routing load and energy consumption. A major design issue for an efficient and effective routing protocol for real MANETs is, therefore, to achieve optimum values of performance parameters under network scenarios where nodes are subjected to different types of mobility that dynamically change the network topology. Our simulative study on MANET routing protocols and mobility models aims to determine the performance of current MANET routing protocols with respect to various mobility models implemented in ns-2. We compare a number of reactive and proactive routing protocols including AODV, DSR, DSDV, OLSR and DYMO. The results of our extensive network simulations are tabulated along with a comprehensive analysis. The effort allows a fair comparison of the capabilities and limitations of different types of mobility patterns and their suitability for contemporary MANET routing protocols.

Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes that dynamically form a network temporarily without any support of central management. Routing in Mobile ad hoc network is extremely challenging because of its limited bandwidth, battery constraints, routing overhead, asymmetric link, speed, scalability, packet loss and quality of services. The widely accepted existing routing protocols are designed to accommodate the needs of such self-organized networks. The protocol to be chosen must cover all states of a specified network and never is allowed to consume too much network resources by protocol overhead traffic. This paper deals with the classification of Mobile ad hoc routing protocols and also presents some specified protocols according to that classification.

Named Data Networking (NDN) is a promising information-centric architecture for the future Internet that is also gaining momentum in wireless ad hoc networks as an alternative paradigm to traditional IP networking. NDN shares with other information-centric proposals the same innovative concepts, such as named content, name-based routing, and in-network content caching. These principles and the simple and robust communication model, based on Interest and Data packets exchange, make NDN especially appealing for deployment in wireless ad hoc environments, characterized by a broadcast error-prone channel and time-varying topologies.

Mobile Ad hoc Networks (MANET) have been highly vulnerable to attacks due to the dynamic nature of its network infrastructure. Among these attacks, routing attacks have received considerable attention since it could cause the most devastating damage to MANET. Even though there exist several intrusion response techniques to mitigate such critical attacks, existing solutions typically attempt to isolate malicious nodes based on binary or naïve fuzzy response decisions. However, binary responses may result in the unexpected network partition, causing additional damages to the network infrastructure, and naïve fuzzy responses could lead to uncertainty in countering routing attacks in MANET. In this paper, we propose a risk-aware response mechanism to systematically cope with the identified routing attacks. Our risk-aware approach is based on an extended Dempster-Shafer mathematical theory of evidence introducing a notion of importance factors. In addition, our experiments demonstrate the effectiveness of our approach with the consideration of several performance metrics.

In wireless multihop networks such as wireless sensor networks (WSNs) and mobile ad hoc networks (MANETs), nodes have to rely on their peer neighbours in transmitting packets to intended destinations. A successful rate of communication in these networks is assured if all nodes in the network fully  cooperate to relay packets for each other. However, due to the existence of nodes with various motives, cooperativeness cannot be ensured and the communication goal is not achieved. Consequently, many cooperation stimulation approaches have been proposed to address node selfishness by using, broadly, incentive-based and punishment-based approaches. These schemes consist of several components including monitoring mechanisms, that need to be optimized in order to provide effective ways to detect and manage selfish  nodes in the networks. This article summarizes existing cooperation stimulation mechanisms and discusses important issues in this field such as false judgment and node collusion, whereby the root of these kinds of problems originates from the inability to obtain accurate evaluation on the behaviour of a node.

In multi-hop wireless systems, the need for cooperation among nodes to relay each other's packets exposes them to a wide range of security attacks. A particularly devastating attack is the wormhole attack, where a malicious node records control traffic at one location and tunnels it to another compromised node, possibly far away, which replays it locally. Routing security in ad hoc networks is often equated with strong and feasible node authentication and lightweight cryptography. Unfortunately, the wormhole attack can hardly be defeated by crypto graphical measures, as wormhole attackers do not create separate packets. They simply replay packets already existing on the network, which pass the cryptographic checks. Existing works on wormhole detection have often focused on detection using specialized hardware, such as directional antennas, etc. In this paper, we present a cluster based counter-measure for the wormhole attack, that alleviates these drawbacks and efficiently mitigates the wormhole attack in MANET. Simulation results on MATLab exhibit the effectiveness of the proposed algorithm in detecting wormhole attacks.

Ultra-wideband (UWB) wireless communication is a promising spread spectrum technology that supports very high data rates and provides precise position information of mobile users. In this paper, we present a position-based quality-of-service (QoS) routing scheme for UWB ad-hoc networks. The scheme applies call admission control and temporary bandwidth reservation for discovered routes, taking into consideration the medium access control (MAC) interactions. Via cross-layer design, it exploits UWB advantages by using the position information in routing and bandwidth reservation. Simulation results demonstrate that the proposed routing scheme is effective in end-to-end QoS support.

In this paper, we introduce a novel reservationbased multiple access protocol for ad hoc networks using directional antennas. First, we investigate the limitations of the extreme reservation schemes, namely omni-directional and directional reservations. We highlight the trade-off between spatial reuse (favors directional reservation) and control/data packet collisions (favors omni-directional reservation). Next, we show that the so-called hybrid reservation schemes fail to balance the trade-off as well. Therefore, we introduce a novel algorithm that balances the aforementioned trade-off via sending reservation messages, that carry information about the required direction of transmission, in all unblocked directions. In addition, we introduce candidate techniques for handling new types of collisions inherent to directional antennas. Finally, we conduct a simulation study that shows considerable performance gains of the proposed scheme over the omni-directional, directional, and hybrid reservation paradigms.

In this paper, we study the case of a limited number of mobile nodes trying to communicate in a large geographic area, forming a delay/disruption tolerant network (DTN). In such networks the mobile nodes are disconnected for significantly long periods of time. Traditional routing protocols proposed for mobile ad hoc networks or mesh networks, which assume at least one path between each source and destination, are ineffective in DTNs. One approach to improve communication is through gossip based protocols because these protocols do not rely on a fixed path. Another approach is to control the movement of the mobile nodes and/or use special mobile nodes called ferry nodes. Others try to employ a fixed infrastructure including stationary relay points. One scheme in stationary relay point approach is to use base stations as relay points which need their own power supply. In this paper, we study a passive approach where mobile nodes deposit/retrieve messages to/ from known stationary locations in the geographic region. Messages are delivered from a source by being deposited at one or more locations that are later visited by the destination. A proposed implementation of our approach using read/writable passive Radio Frequency Identification (RFID) tags, one per point location, is considered in this work. Passive RFID technology is desirable because it operates wirelessly and without the need for attached power. Our simulation results indicate that our approach can achieve competitive message delay and delivery rates. We also demonstrate several techniques for optimizing the stationary relay node placement, namely relay pruning, probability based relay distribution and a genetic algorithm; the genetic algorithm is shown to provide the best solutions to this problem.

The communication in Mobile Ad hoc Network (MANET) is multi-hop in nature wherein each node relays data packets of other nodes thereby spending its resources such as battery power, CPU time and memory. In an ideal environment, each node in MANET is supposed to perform this community service truthfully. However this is not the case and existence of selfish nodes is a very common feature in MANETs. A selfish node is one that tries to utilize the network resources for its own profit but is reluctant to spend its own for others. If such behaviour prevails among large number of the nodes in the network, it may eventually lead to disruption of network. This paper studies the impact of selfish nodes concentration on the quality of service in MANETs.

With the growing usage of wireless sensors in a variety of applications including Internet of Things, the security aspects of wireless sensor networks have been on priority for the researchers. Due to the constraints of resources in wireless sensor networks, it has been always a challenge to design efficient security protocols for wireless sensor networks. An novel elliptic curve signcryption based security protocol for wireless sensor networks has been presented in this paper, which provides anonymity, confidentiality, mutual authentication, forward security, secure key establishment, and key privacy at the same time providing resistance from replay attack, impersonation attack, insider attack, offline dictionary attack, and stolen-verifier attack. Results have revealed that the proposed elliptic curve signcryption based protocol consumes the least time in comparison to other protocols while providing the highest level of security.

With the development of more advanced and efficient control algorithms and communication architectures, UAVs and networks thereof (swarms) now find applications in nearly all possible environments and scenarios. There exist numerous schemes which accommodate routing for such networks, many of which are specifically designed for distinct use-cases. Validation and evaluation of routing schemes is implemented for the most part using simulation software. This approach is however incapable of considering real-life noise, radio propagation models, channel bit error rate and signal-to-noise ratio. Most importantly, existing frameworks or simulation software cannot sense physical-layer related information regarding power consumption which an increasing number of routing protocols utilize as a metric. The work presented in this paper contributes to the analysis of already existing routing scheme evaluation frameworks and testbeds and proposes an efficient, universal and standardized hardware testbed. Additionally, three interface modes aimed at evaluation under different scenarios are provided.

This paper addresses the path selection problem from a known sender to the receiver. The proposed work shows path selection us ing genetic algorithm (GA) and simulated annealing (SA) approaches. In genetic algorithm approach, the multi point crossover and mutation helps in determining the optimal path and also alternate path if required. The input to both the algorithms is a learnt module which is a part of the cognitive router that takes care of four QoS parameters. The aim of the approach is to maximize the bandwidth along the forward channels and minimize the route length. The population size is considered as the N nodes participating in the network scenario, which will be limited to a known size of topology. The simulated results show that, by using genetic algorithm approach, the probability of shortest path convergence is higher as the number of iteration goes up whereas in simulated annealing the number of iterations had no influence to attain better results as it acts on random principle of selection.

Cognitive radio is an enabling technology of dynamic spectrum access (DSA) networking. In DSA, unlicensed secondary users can coexist with primary licensed users and can share the radio spectrum opportunistically. Broadcasting is an important networking primitive that is useful for many CRN applications such as control information dissemination, warning notification, etc. Unfortunately, the sporadic channels availability degrades the performance of broadcast routing. The quality of a broadcast transmission on a particular channel depends on the channel quality of all the receivers for the same transmitter. Current broadcast routing protocols lack transmission quality awareness. In this paper, we develop a transmission quality-aware broadcasting framework, comprising algorithm for transmission quality-aware broadcast routing in multi-radio dynamic-spectrum-access CRNs, and formulate a transmission quality metric wherein we consider a receiver-centric view rather than a transmission-centric view. We perform a detailed simulation performance evaluation of our proposed framework using OMNeT++. The proposed broadcast routing algorithm is validated by comparing results with state-of-the-art routing algorithms. Analysis of the results shows average performance gains of approximately 40 percent in throughput and packet delivery ratio.

Recent trends in compact computing and wireless technologies are expansion of ad hoc network.
Ad hoc network consists of versatile flat forms which are free to move expeditiously. Ad hoc networks are
multi-hop network that use wireless communication for transmission without any fixed infrastructure.
The networks are form and deform on-the-fly without the need for any system. Ad hoc structure does not
require an access point, it is easy to setup, especially in a small or temporary network. Each node in the
network forwards the packet without the need of central administration. In ad hoc network, node acts as a
router to send and receive the data. An advantage of the system is robustness, flexibility and mobility.
Ad hoc network are capable for analyzing radio propagation environment to optimize the performance.
This typically requires that the network node have positioning capability as well as memory to recall
geographical local condition. An ad hoc network typically refers to any set of network where all devices have
equal status on a network and are free to associate with any other ad hoc network device in link range.
Ad hoc network often refers to a mode of operation of IEEE802.11 wireless networks. This review is focused
on the applications, advantages and challenges of ad hoc networks.

Information-centric networks (ICNs) have emerged as a prominent future Internet architecture. They work on the principle that, in today's society, a network should be optimised towards the delivery of information, rather than the transit of messages between pre-determined end hosts. At the same time, another prominent research direction has been the delay-tolerant networking initiative, which argues that networks must explicitly support the tolerance of high delays and disruptions in end-toend paths. We believe that this observation is pervasive across a number of applications and network technologies and should therefore be strongly considered in any future ICN designs. This paper explores the potential of combining these concepts into an information-centric delay-tolerant network (ICDTN). Through a qualitative and quantitative investigation, we present arguments in favour of the design, as well as important research challenges.

Featured Application: Privacy ensuring emergency vehicle approaching warning system. Abstract: With the deployment of Vehicular Ad hoc Networks (VANETs), new transport safety and efficiency applications are emerging. One of the fields where the adoption of information and communication technologies (ICT) is expected to bring great benefits, is emergency systems. A properly designed emergency vehicle warning system should provide car drivers with adequate reaction times and additional information, complementing the currently used lights and sirens. The objective is to increase road safety and to create conditions for a fast and reliable movement of emergency vehicles (EVs). The available literature addressing privacy issues in VANET-based emergency vehicle warning systems is strongly limited. In this paper, the privacy ensuring emergency vehicle approaching warning system (PEEV-WS) is proposed based on a requirements analysis. Privacy is ensured by avoiding transmissions of sensitive information (e.g., expected EV route) over the wireless channel. This is achieved by assigning the decision-making responsibility to an EV and determining which vehicles can potentially interfere with the EV in the near future, and to notify those vehicles only by unicasting vehicle-customized information. The performance of the system is evaluated by federated telco-traffic simulations in terms of end-to-end delay and message delivery probability for three commonly used ad hoc routing protocols-Ad hoc On-Demand Distance Vector (AODV), Greedy Perimeter Stateless Routing (GPSR), and Dynamic MANET On-demand (DYMO), as well as in terms of reaction time, which the system provides to the drivers. Despite low applicability of the ad hoc routing protocols for vehicular communication, especially for low-latency and high-frequency applications, the simulations of the communication network demonstrate that the AODV protocol, with the modified configuration, can support the emergency vehicle warning system. The traffic simulations confirm that the system has the potential to provide drivers with sufficient reaction time.

Energy consumption is a constraint in the design architecture of wireless sensor networks (WSNs) and internet of things (IoT). In order to overcome this constraint, many techniques have been proposed to enhance energy efficiency in WSNs. In existing works, several innovative techniques for the physical, the link, and the network layer of OSI model are implemented. Energy consumption in the WSNs is to find the best compromise of energy consumption between the various tasks performed by the objects, the detection, the processing, and the data communication tasks. It is this last task that consumes more energy. As a result, the main objective for the WSNs and the IoT is to minimize the energy consumed during this task. One of the most used solutions is to propose efficient routing techniques in terms of energy consumption. In this chapter, the authors present a review of related works on energy efficiency in WSNs and IoT. The network layer routing protocols are the main concerns in this chapter. The interest is focused on the issue of designing data routing techniques in WSNs and IoT.

In this paper, we propose two cross layer geographic forwarding schemes which address congestion in wireless video sensor networks (VSN) to provide reliable video delivery. The first scheme Load Balanced Reliable Forwarding (LBRF) introduces the notion of local load balancing where a sensor dynamically determines the next hop among the alternative neighbors providing positive advancement towards the sink by considering the balance of their buffer occupancy levels at the time of delivery. LBRF utilizes a modified version of SMAC where the packet structure as well as the operation of SMAC is modified for the accurate monitoring of the buffer occupancy conditions of the neighbors. The second scheme Directional Load Balanced Spreading (DLBS) combines local and direction-based (spatial) load balancing approaches to provide more reliable and faster video delivery by benefiting from the advantages of both approaches. The performance of the forwarding schemes are compared using simulation with two geographic routing schemes where one applies no load balancing and the other applies spatial load balancing. The results show that both LBRF and DLBS provide more reliable video delivery as compared to other schemes, whereas DLBS is more reliable and faster as compared to LBRF. In addition, DLBS provides more energy efficient video delivery in terms of energy expenditure per successfully delivered frame to the sink as compared to LBRF and the other two schemes.

—Recently, MANETs have witnessed rapid development due to the low cost, diversity and simplicity of mobile devices. Such devices can form a reliable network in a short time for use as a rescue information system after a natural disaster, where the communication infrastructure may no longer be available or accessible. Because the nodes in such a network are free to move at any time in the absence of centralized control, routing is considered to be the most challenging issue. Moreover, some routing protocols, such as Neighbor Coverage-Based Probabilistic Rebroadcast (NCPR), completely rely on preset variables, which are required to be set by the system administrator based on the scenario. Unfortunately, the setting that is proper for a specific scenario is not suitable for another scenario. In addition, some other routing protocols, such as Ad hoc On-demand Distance Vector (AODV), employ the Route REQuest message (RREQ) flooding scheme to find a path to a particular destination in the route discovery stage. Although the flooding scheme guarantees better reachability, it introduces undesirable routing overhead, which in turn leads to system performance degradation. Thus, this paper proposes a novel routing protocol, neighbor-based Dynamic Connectivity Factor routing Protocol (DCFP), that is able to dynamically probe the status of the underlying network without the intervention of a system administrator based on a novel connectivity metric, while reducing the RREQ overhead using a new connectivity factor. Furthermore, extensive simulation experiments are conducted to evaluate the performance of the proposed DCFP, where the NCPR and AODV are used as a benchmark. The proposed DCFP manages to address the need for preset variables in NCPR. Simulation results show that DCFP outperforms both NCPR and AODV in terms of end-to-end delay, normalized routing overhead, MAC collision, energy consumption, network connectivity and packet delivery ratio due to its novel mechanism for reducing redundant RREQ.

Numerous studies have shown that concurrent transmissions can help to boost wireless network performance despite the possibility of packet collisions. However, while these works provide empirical evidence that concurrent transmissions may be received reliably, existing signal capture models only partially explain the root causes of this phenomenon. We present a comprehensive mathematical model for MSK-modulated signals that makes the reasons explicit and thus provides fundamental insights on the key parameters governing the successful reception of colliding transmissions. A major contribution is the closed-form derivation of the receiver bit decision variable for an arbitrary number of colliding signals and constellations of power ratios, time offsets, and carrier phase offsets. We systematically explore the factors for successful packet delivery under concurrent transmissions across the whole parameter space of the model. We confirm the capture threshold behavior observed in previous studies but also reveal new insights relevant to the design of optimal protocols: We identify capture zones depending not only on the signal power ratio but also on time and phase offsets.

Background Aggressive angiomyxoma is a rare locally aggressive mesenchymal tumor of unknown etiology usually affecting the vulva, perianal region, buttocks or pelvis of reproductive age women. Material A series of three cases, one each of vaginal, vulval and labial angiomyxoma is being presented. The etiology, presentation, diagnosis and management of this rare genital tumor are outlined. Conclusion Angiomyxoma of vulva and vagina refers to a rare disease; diagnosis is not at all clinical, thus, cases presenting as bartholin cyst, benign vulval lesions and vaginal wall cysts should have complete radiological work up before excision, as pre-diagnosis can change the treatment modality and prognosis of patient.

The mobile devices of today present a great opportunity for building large-scale mobile sensing and information sharing systems that could be used for emergency situations and rescue scenarios. Usually in large catastrophes, one of the first things that get’s effected is the mobile cellular network, either by the loss or damage of its infrastructure, or by the high levels of congestion in the cellular network. In this case the use of the sensory and communication capabilities of a smartphones, tablet or any other mobile device that requires a connection to the cellular network would be limited or even pointless. Using mobile ad-hoc networks (MANET), we can get around this problem, by using smartphones and all the other mobile devices to create a dynamic temporary network that can share information between them selves without the need for any additional infrastructure.

The field of Wireless Sensor Networks (WSNs) is experiencing a resurgence of interest and a continuous
evolution in the scientific and industrial community. The use of this particular type of ad hoc network is
becoming increasingly important in many contexts, regardless of geographical position and so, according
to a set of possible application. WSNs offer interesting low cost and easily deployable solutions to perform
a remote real time monitoring, target tracking and recognition of physical phenomenon. The uses of these
sensors organized into a network continue to reveal a set of research questions according to particularities
target applications. Despite difficulties introduced by sensor resources constraints, research contributions
in this field are growing day by day. In this paper, we present a comprehensive review of most recent
literature of WSNs and outline open research issues in this field.

The hierarchical routing algorithm is categorized as a kind of routing method using node clustering to create a hierarchical structure in large‐scale mobile ad hoc network (LMANET). In this paper, we proposed a new hierarchical clustering algorithm (HCAL) and a corresponded protocol for hierarchical routing in LMANET. The HCAL is designed based on a cost metric in the form of the link expiration time and node's relative degree. Correspondingly, the routing protocol for HCAL adopts a reactive protocol to control the existing cluster head (CH) nodes and handle proactive nodes to be considered as a cluster in LMANET. Hierarchical clustering algorithm jointly utilizes table‐driven and on‐demand routing by using a combined weight metric to search dominant set of nodes. This set is composed by link expiration time and node's relative degree to establish the intra/intercommunication paths in LMANET. The performance of the proposed algorithm and protocol is numerically evaluated in average end‐ to‐end delay, number of CH per round, iteration count between the CHs, average CH keeping time, normalized routing overhead, and packet delivery ratio over a number of randomly generated benchmark scenarios. Furthermore, to corroborate the actual effectiveness of the HCAL algorithm, extensive performance comparisons are carried out with some state‐of‐the‐art routing algorithms, namely, Dynamic Doppler Velocity Clustering, Signal Characteristic‐Based Clustering, Dynamic Link Duration Clustering, and mobility‐based clustering algorithms. KEYWORDS cluster head (CH), clustering, cost metrics, hierarchical routing algorithm, mobile ad hoc networks (MANET)

The purpose of this study was to examine the effects of static and dynamic stretching within a pre-exercise warm-up on vastus medialis muscle activity during instep kicking and ball velocity in soccer players. The kicking motions of dominant legs were captured from using six synchronized high-speed infra-red cameras at 200 Hz and Electromyography at 100 Hz. There was significant difference in vastus medialis activity after dynamic stretching relative to no stretching condition (0.12 ± 0.06 mV) versus static stretching relative to no stretching condition (-0.21 ± 0.10 mV) with p < 0.001). In addition, there was also a significant difference in ball velocity after dynamic stretching relative to no stretching condition (4.53 ± 2.10 m/s) versus static stretching relative to no stretching condition (-1.48 ± 2.43 m/s) with p < 0.003. We concluded that dynamic stretching during the warm-up, as compared to static stretching, is probably more effective as preparation for optimal muscle activity and finally have high ball velocity which is required in soccer.

http://www.degruyter.com/view/j/hukin.2010.24.issue--1/v10078-010-0017-2/v10078-010-0017-2.xml

The use of smart directional antennas in ad-hoc networks has recently received much attention since this technology offers a way to optimize power consumption , increase spatial reuse and reduce co-channel interference. Neighbor discovery is an important first step for these self-configured networks because it makes it possible to identify the active nodes surrounding a given node and this information is essential for other higher layer protocols like medium access control, routing and topology control protocols. In this article, we present two algorithms that aim to take full advantage of the capabilities of smart antennas. The first one aims to increase the number of discovered nodes by considering the nodes that are located in the second-hop neighborhood of a node. The second algorithm seeks to reduce the number of hops in a route between source and destination nodes by using the extended range that can be achieved when the nodes are equipped with directional antennas. The results of the simulations have shown a reduction in the end-to-end delay and an increase in the network throughput when the scheme is compared with other reactive routing protocols.

Hierarchical routing techniques have long been known to increase network scalability by constructing a virtual backbone. Even though MANETs have no physical backbone, a virtual backbone can be constructed by finding a connected dominating set (CDS) in the network graph. Many centralized as well as distributed algorithms have been designed to find a CDS in a graph (network). Theoretically, any centralized algorithm can be implemented in a distributed fashion, with the tradeoff of higher protocol overhead. Because centralized approaches do not scale well and because distributed approaches are more practical especially in MANETs, we propose a fast distributed connected dominating set (FDDS) construction in MANETs. FDDS has message and time complexity of O(n) and O(D 2 ), where n is the number of nodes in the network and D is the maximum node degree. According to our knowledge, FDDS achieves the best message and time complexity combinations among the previously suggested approaches. Moreover, FDDS constructs a reliable virtual backbone that takes into account (1) node's limited energy, (2) node's mobility, and (3) node's traffic pattern. Our simulation study shows that FDDS achieves a very low network stretch. Also, when the network size is large, FDDS constructs a backbone with size smaller than other well known schemes found in the literature.

Over the course of the last decade, there have been several improvements in the performance of Integer Linear Programming (ILP) and Boolean Satisfiability (SAT) solvers. These improvements have encouraged the application of SAT and ILP techniques in modeling complex engineering problems. One such problem is the Clustering Problem in Mobile Ad-Hoc Networks. The Clustering Problem in MANETs consists of selecting the most suitable nodes of a given MANET topology as clusterheads, and ensuring that regular nodes are connected to clusterheads such that the lifetime of the network is maximized. This paper proposes the development of an improved ILP formulation of the Clustering Problem. Additionally, various enhancements are implemented in the form of extensions to the improved formulation, including the establishment of intracluster communication, multihop connections and the enforcement of coverage constraints. The improved formulation and enhancements are implemented in a tool designed to visually create network topologies and cluster them using state-of-the art Generic ILP and SAT solvers. Through this tool, feasibility of using the proposed formulation and enhancements in a real-life practical environment is assessed. It is observed that the Generic ILP solvers, CPLEX and SCIP, are able to handle large network topologies, while the 0-1 SAT-based ILP solver, BSOLO, is effective at handling the smaller scale networks. It is also observed that while these enhanced formulations enable the generation of complex network solutions, and are suitable for small scale networks, the time taken to generate the corresponding solution does not meet the strict requirements of a practical environment. -Hajj, -Optimizing Complex Cluster Formation in MANETs using SAT/ILP Techniques,‖ IEEE Sensors, 2013 2 II. BACKGROUND