This paper explores the idea of predictive dynamic spectrum access (PDSA). Modern spectrum resource allocation research typically divides users into two classes: primary users and secondary users. Primary users own licenses to particular frequency bands and are allowed to use it whenever they wish. Secondary users can reuse the frequencies when they are not being used by a primary user. The goa...

Cognitive Radio (CR) is an intelligent radio that can dynamically access the radio spectrum. Secondary users in Cognitive Radio Network (CRN) can access the licensed spectrum without causing harmful interference to primary users. The performance of cognitive radio networking functionalities depends on the properties of the spectrum band in use. This necessitates a crosslayer design in the entir...

The concept of spectrum eficient, Paul K. Lee, Jeffrey A. Rudin Sanders, A Lockheed Martin Company PTP1-2C39, P. O. BOX 868 Nashua, NH 03061 anti-jam (A/J), high @equency (HF) communications is discussed in this paper. The HF concept is intended for mobile, beyond line qf sight (BLOS) military communications for use in the 21st century. Spectrum ef>ciency and fast jiequency hopping ofler opport...

in order to decrease the discharge from sulfide mine flotation plants, treatment and reuse approaches based on our previous wastewater monitoring experiments were explored in these plants. the flotation wastewater was collected from the case plant and was treated with coagulation sedimentation and activated carbon adsorption. then, the effluent was examined for reuse in the flotation process. f...

Abstract Spectrum sensing (SS) has been heatedly discussed due to its capacity discover the idle registered spectrum bands, which effectively alleviates shortage of by reuse. Energy detector (ED) is widely accepted for SS as complexity very low. In this paper, an adaptive sampling scheme proposed improve performance ED, where point received signal adaptively adjusted with environment signal-to-...

Piazza leonardo Da Vinci, 32 20133 Milano, ITALY fax: +39-2-2399-3413; e-mail: last [email protected] Abstract— Recently, a new method for achieving spectrum reuse in cellular systems, called Capture-Division Packetized Access (CDPA), has been introduced. The method uses a single frequency in all cells, and uses packet switching and packet retransmission as a means to overcome destructive coc...

Two major challenges for evolving LTE (Long Term Evolution) networks are to achieve enhanced system capacity and cell coverage compared with WCDMA (Wideband Code Division Multiple Access) system. Effective utilization of radio resources as well as dense spectrum reuse are at the core to attain these targets. However, dense frequency reuse may increase inter-cell interference, which in turn seve...

Studies of ad hoc wireless networks are rapidly gaining popularity due to its varied and innovative applications. Medium Access Control (MAC) protocols in such networks are responsible to coordinate access among active nodes. Wireless nodes are largely powered by batteries which restricts the quantity of energy available to the nodes. Routing for wireless nodes is incorporated with power saving...

Global connectivity cannot be guaranteed by terrestrial networks due to the lack of infrastructure in rural areas. Neither can satellite networks assure this due to lack of signal penetration and capacity coverage issues in densely populated areas. To bridge this gap, we propose an Orthogonal Frequency Domain (OFDM) based hybrid architecture where users are provided service by existing mobile n...