cognitive-mac-coexistence.rar - In last decades, the demand of wireless spectrum has
increased rapidly with the development of mobile communication
services. Recent studies recognize that traditional fi xed spectrum
assignment does not use spectrum effi ciently. Such a wasting
phenomenon could be amended after the present of cognitive
radio. Cognitive radio is a new type of technology that enables
secondary usage to unlicensed user. This paper presents an
Opportunistic Cognitive MAC Protocol (OC-MAC) for cognitive
radios to access unoccupied resource opportunistically and coex-
ist with wireless local area network (WLAN). By a primary traffi c
predication model and transmission etiquette, OC-MAC avoids
producing fatal damage to licensed users. Then a ns2 simulation
model is developed to evaluate its performance in scenarios with
coexisting WLAN and cognitive network.,2012-04-10 05:52:13,下载23次
WSN_OPNET.rar - Wireless Sensor Networks (WSNs) have attracted much attention in recent years. The potential applications of WSNs
are immense. They are used for collecting, storing and sharing sensed data. WSNs have been used for various applica-
tions including habitat monitoring, agriculture, nuclear reactor control, security and tactical surveillance. The WSN
system developed in this paper is for use in precision agriculture applications, where real time data of climatologically
and other environmental properties are sensed and control decisions are taken based on it to modify them. The architec-
ture of a WSN system comprises of a set of sensor nodes and a base station that communicate with each other and
gather local information to make global decisions about the physical environment. The sensor network is based on the
IEEE 802.15.4 standard and two topologies for this application. ,2012-04-10 05:49:40,下载35次
CR-OPNET.rar - In the last few years, there has been enormous improvement in mobile communication services.
Due to this rapid growth in the field of communications, the demand for wireless spectrum has
increased rapidly. In the early days in order to remove the interference problem, the spectrum
was assigned statically. To assign the spectrum statically, the fixed spectrum assignment policy
was used. Due to the fixed spectrum assignment policy, the spectrum was not efficiently utilized
and remained vacant most of the time. The study by Federal Communications Commission
(FCC) shows that the spectrum is available but its usage is not efficient. Such kind of spectrum
inefficiency can be overcome by the use of Cognitive Radio.,2012-04-09 09:51:43,下载40次
Cooperative-Communications-and-Networking-2010.ra - cooperative communications,2012-03-22 09:17:50,下载5次
05752426.rar - Optimal Resource Allocation for MIMO Ad Hoc
Cognitive Radio Networks,2012-03-22 09:07:16,下载20次
04797533.rar - Optimal Resource Allocation for MIMO Ad Hoc
Cognitive Radio Networks,2012-03-22 09:02:43,下载12次