This paper develops a multiple channel assignment model, which allows to take advantage of spectrum opportunities in cognitive radio networks in the most efficient way. The developed scheme allows making several assignments of available and frequency adjacent channel, which require a bigger bandwidth, under an equality environment. The hybrid assignment model it is made by two algorithms, one t...

In this dissertation, we consider the problem of assigning spectrum to wireless local-area networks (WLANs). In line with recent IEEE 802.11 amendments and newer hardware capabilities, we consider situations where wireless nodes have the ability to adapt not only their channel center-frequency but also their channel width. This capability brings an important additional degree of freedom, which ...

An adaptive transmission protocol is described and evaluated for use in wireless communication networks that employ dynamic spectrum assignment. The protocol interacts with a spectrum assignment system to select the modulation format and symbol transmission rate for each session. The power is adjusted during the initial part of each session, and code-rate adaptation is employed to compensate fo...

With the advances of cognitive radio technologies, Dynamic Spectrum Access (DSA) has received increasing attention. For dynamic spectrum access, a good spectrum assignment algorithm often considers the spectrum demands of different devices and assigns contiguous and variable bandwidth to them. However, if the DSA devices at a location belong to two or more entities, a selfish entity may want to...

Spectral comparison is an important part of the assignment of the absolute configuration (AC) by vibrational circular dichroism (VCD), or equally by Raman optical activity (ROA). In order to avoid bias caused by personal interpretation, numerical methods have been developed to compare measured and calculated spectra. Using a neighbourhood similarity measure, the agreement between a computed and...

Abstract—Dynamic spectrum networks enable fast deployment of new wireless technologies by effectively utilizing allocated yet unused wireless spectrum. By sensing and utilizing available wireless channels, cognitive radio devices can provide high throughput, low latency communication. Existing schemes for channel assignment suffer drawbacks in throughput and reachability in the presence of loca...