In this paper satellite wave propagation at Ku and Ka band is considered. The design and simulation of a typical satellite beacon receiver at Ka band is designed and simulated for the future works. Also rain attenuation prediction at Ku band using satellite signal beacon measurement and simulations for Iran Telecommunication Research Center (ITRC) are presented. The measurement setup consists o...

Hyperspectral remote sensing records reflectance or emittance data in a large sum of contiguous and narrow spectral bands, and thus has many information in detecting and mapping the mineral zones. On the other hand, the geological and geophysical data gives us some other fruitful information about the physical characteristics of soil and minerals that have been recorded from the surface. ...

The purpose of this investigation was to determine whether Belding's ground squirrels (Urocitellus beldingi) from areas rich in beacons perform differently in a task of spatial memory compared with squirrels from beacon-thin areas. To assess the role of environmental experience in spatial memory, wild-born squirrels with several days of experience in the field were compared with squirrels born ...

The present paper focuses on the two time scale dynamics generated by 2D polynomial noninvertible maps T of (Z0−Z2) and (Z1−Z3−Z1) types. This symbolism, specific to noninvertible maps, means that the phase plane is partitioned into zones Zk, where each point possesses the k real rank-one preimages. Of special interest here is the structure of slow and fast motion sets of such maps. The formati...

Denial of Service (DoS) attacks pose a fast-growing threat to network services in the Internet, but also corporate Intranets and public local area networks like Wi-Fi hotspots may be affected. Especially protocols that perform authentication and key exchange relying on expensive public key cryptography are likely to be preferred targets. A well-known countermeasure against resource depletion at...

IEEE802.15.4 is a standard which specifies the physical and medium access control for low-rate, low-cost, low-power Wireless Personal Area Networks (LR-WPANs). However, this protocol suffers from several types of collisions; In spite of being able to avoid data packets colliding with each other by using CSMA/CA, the risk of beacon collisions still remains specially in a cluster-tree network top...

In an infrastructure Basic Service Set (BSS) beacon frames are transmitted periodically by the Access Point (AP) and announce the presence of a wireless network. It mainly consists of network specific information and thus one of its main purposes is the "advertisement" of this information. Based on this information mobile devices can take many decisions, for example, whether to attempt associat...