adequate coverage is one of the main problems for distributed wireless sensor networks and the effectiveness of that highly depends on the sensor deployment scheme. given a finite number of sensors, optimizing the sensor deployment will provide sufficient sensor coverage and save power of sensors for movement to target location to adequate coverage. in this paper, we apply fuzzy logic system to...

in wireless channel the noise has a zero mean. this channel property can be used in the enhancement of the noise performance in the digital receivers by oversampling the received signal and calculating the decision variable based on the time average of more than one sample of the received signal. the averaging process will reduce the effect of the noise in the decision variable that will approa...

Wireless sensor networks, due to the characteristics of sensors such as wireless communication channels, the lack of infrastructure and targeted threats, are very vulnerable to the various attacks. Routing attacks on the networks, where a malicious node from sending data to the base station is perceived. In this article, a method that can be used to transfer the data securely to prevent attacks...

grid computing is a term referring to the combination of computer resources from multiple administrative domains to reach a common computational platform. mobile computing is a generic word that introduces using of movable, handheld devices with wireless communication, for processing data. mobile computing focused on providing access to data, information, services and communications anywhere an...

because of approaches to learning in every place and at any time, ubiquitous learning with knowledge of the context and framework, and due to the development of wireless technologies and sensors, the learning process has changed. mobile learning and ubiquitous learning as models of e-learning that refer to the acquisition of knowledge, attitudes and skills through wireless technologies. the eff...

in wireless sensor networks, optimal consumptionof energy and having maximum life time are important factors. in this article attempt has been made to send the data packets with particular reliability from the beginning based on aodv protocol. in this way two new fields add to the routing packets and during routing and discovering of new routes, the lowest remained energy of nodes and route tra...

sensor networks generally consist of a very great number of sensor nodes which will be spread into a vast environment and aggregate data out of it. the sensor nodes are afflicted with some limitations as follows memory, reception, communication as well as calculation capability, and battery power. the transmission of a great amount of extra data increases data transmission and proportionally in...

By definition, IEEE 802.11 wireless LANS (WLANs) are constantly in flux. There is no way to predict where a particular client will be at any moment, making it equally impossible to predetermine the load on any wireless access point (AP). How will 802.11 Wi-Fi networks running in adjoining offices or on different floors affect one another? Even something as seemingly trivial as rearranging cubic...

network sensors consist of sensor nodes in which every node covers a limited area. the most common use ofthese networks is in unreachable fields.sink is a node that collects data from other nodes.one of the main challenges in these networks is the limitation of nodes battery (power supply). therefore, the use oftopology control is required to decrease power consumption and increase network acce...