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In this paper, we evaluate and compare the performanceof four different routing protocols in a many-to-onecommunication opportunistic network. Seven groups with threestationary sensor nodes sense the temperature, humidity andwind speed and send these data to a stationary destination nodethat collect them for statistical and data analysis purposes. Vehicles moving in Tirana city roads during the opportunisticcontacts...
In this paper, we evaluate and compare the performance of single-copy and multiple-copy routing protocols in a realistic Vehicular Delay Tolerant Network (VDTN) scenario. The simulations are conducted with the Opportunistic Network Environment (ONE) simulator. The performance is analyzed using delivery probability, overhead ratio, average latency, average number of hops and average buffer time metrics...
Method of moments in time domain (MoM-TD) is a comparatively recent yet very interesting numerical technique especially in the case of ultra wide band signals or transients. In this context, the method of moments in time domain (MoM-TD) is very interesting. Implementing the MoM-TD requires three different approaches using Wire Grid Model, Surface Patch Model and the Attachment Model. All MoM-TD implementations...
In this work, we evaluate the performance ofthree routing protocols epidemic, sprayandwait and maxpropin Vehicular Delay Tolerant Networks (VDTNs). We study theimpact of vehicles density and ttl on the network performance. The simulations are conducted with the Opportunistic NetworkEnvironment (ONE) simulator. The performance is analyzedusing delivery probability, overhead ratio, average latencyand...
Vehicular networks have highly dynamic network topology and characterized by disruptive and intermittent connectivity. Vehicular Delay-Tolerant Network (VDTN) architecture is used to deal with these connectivity constraints. In order to handle disconnections and long delays in vehicular network scenarios, VDTN uses store-carry-and-forward approach. In this work, we evaluate the performance of three...
Wireless Mesh Networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In this work, we evaluated WMN-SA system which is based on Simulated Annealing (SA) to find an optimal location assignment for mesh routers. As evaluation metrics,...
Wireless Mesh Networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In this work, we evaluated WMN-HC system which is based on Hill Climbing (HC) to find an optimal location assignment for mesh routers. As evaluation metrics, we used...
The proliferation of corporate and end user mobile internet services offered for smartphones and tablets, makes it necessary to monitor the quality of service and experience provided by mobile internet service providers. In this context, we introduce a low cost tool for monitoring network parameters as received signal power and network responding time. The application is used for signal and latency...
A Mobile Ad hoc Network (MANET) is a multihop wireless network in which the mobile nodes are dynamic in nature and has a limited bandwidth and minimum battery power. Due to this challenging environment the mobile nodes can be grouped into clusters to achieve better stability and scalability. Grouping the mobile nodes is called clustering, in which a leader node is elected to manage the entire network...
With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In this paper, we used our proposed and implemented system based on Hill Climbing algorithm, called WMN-HC for mesh router node placement in WMNs. We analyze WMN-HC simulation system data...
In this paper, we deal with connectivity and coverage problem in Wireless Mesh Networks (WMNs). We used Friedman test to check if we can compare Genetic Algorithm (GA) and Hill Climbing (HC). We found out that GA and HC have differences in their performance. Then, we used the implemented systems WMN-GA and WMN-HC to evaluate and compare the performance of the systems for different distributions of...
Finding an optimal solution is computationally hard for most combinatorial optimization problems. Therefore the use of heuristics methods aims at finding, if not optimal, near optimal solutions in reasonable amount of computation time. Due to lack of knowledge about the landscape of fitness function, searching the solution space by heuristic methods becomes very challenging. One can search the solution...
In this paper, we deal with connectivity and coverage problem in Wireless Mesh Networks (WMNs). We used Friedman test to check if we can compare Tabu Search (TS) and Hill Climbing (HC). We found out that TS and HC have differences in their performance. Then, we used the implemented systems WMN-TS and WMN-HC to evaluate and compare the performance of the systems for different distributions of mesh...
In this paper three different acquisition algorithms are implemented in a GPS software receiver and compared by the correlation strategy employed. Their theoretical models are first analyzed and then implemented in Mat lab. Both simulated GPS data and realistic signals from a Sat-Surf receiver are used to verify the performance of the acquisition schemes. The software acquisition approach provides...
Data mining is an active field of research and development aiming to automatically extract "knowledge" from analyzing data sets. Knowledge can be defined in different ways such as discovering (structured, frequent, approximate, etc.) patterns in data, grouping/clustering/bi-clustering data according to one or more criteria, finding association rules, etc. Such knowledge is then fed-back...
Call Admission Control (CAC) is one of the resource management functions, which regulates network access to ensure QoS provisioning. However, the decision for CAC is very challenging issue due to user mobility, limited radio spectrum, and multimedia traffic characteristics. In this paper, we propose a new CAC scheme which considers for acceptance decision except other parameters also the security...
Ground stations are part of any satellite network, providing communication with satellites. Low Earth Orbit (LEO) satellites are used for public communication and for scientific purposes. The communication quality depends on the performance of the satellite ground station, in addition to that of the satellite. Usually, LEO satellites communicate with ground stations at S-band. Ground stations can...
Ground stations are part of any satellite network, providing communication with satellites. Low Earth Orbit (LEO) satellites are used for public communication and for scientific purposes. The communication quality depends on the performance of the satellite ground station, in addition to that of the satellite. Usually, LEO satellites communicate with ground stations at S-band. Ground stations can...
In this work, a simple, accurate and very efficient method for the evaluation of the field in the vicinity of GSM antennas of the base-station (BS) in urban areas is presented. The method is based on the replacement of the antenna panel with a group of discrete source emitters. Also, a geometrical approximation is used for the evaluation of the environment's influence. The approximate results are...
Estimation of peak power density in the vicinity of cellular base stations and comparison of theoretical values with exposure limits for public, offers the possibility of knowing the safety distance from those antennas. In this paper, we present results of estimations for the peak power density radiated from antennas, by eliminating or not considering reflected waves from different surfaces. This...
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