Third generation mobile systems are gradually being deployed in many developed countries in hotspot areas. However, owing to the amount of new infrastructures required, it will still be some time before 3G is ubiquitous, especially in developing countries. One possible cost effective solution for deployments in these areas is to use High Altitude Platforms (HAPs) (Collela et al., 2000; Djuknic ...

Policy discussions and corporate strategies on machine learning are increasingly championing data reuse as a key element in digital transformations. These aspirations often coupled with focus responsibility, ethics transparency, well emergent forms of regulation that seek to set demands for conduct the protection civic rights. And Protective measures include methods traceability assessments ‘go...

In the Object-Oriented approach a designer can, given an existing base class, use inheritance to build a derived class that extends, or that slightly differs from the base class. But in order to exploit the full potential of inheritance to build systems incrementally, the designer must also be able to reason about the derived class incrementally. This paper presents a specification notation and...

Decentralized dynamic spectrum allocation (DSA) that exploit adaptive antenna array interference mitigation (IM) diversity at the receiver, is addressed in interference-limited environment with high level of frequency reuse. The system consists of base stations (BSs) that may belong to different providers in license-exempt spectrum, who can optimize uplink frequency allocation to their subscrib...

Wireless applications gradually enter every aspect of our life. Unfortunately, these applications must reuse the same scarce spectrum, resulting in increased interference and limited usability. Cognitive Radio proposes to mitigate this problem by adapting the operational parameters of wireless devices to varying interference conditions. However, it involves an increase in cost. In this paper we...

In this contribution, we investigate the idea of using cognitive radio to reuse locally unused spectrum to increase the total system capacity. We consider a multiband/wideband system in which users wish to communicate to the base station, subject to correlated scattering. We assume that each user knows only his channel and the unused spectrum through adequate sensing. Under this scheme, a cogni...

Nowadays, the demand for wireless mobile services is copious, and will continue increasing in the near future. Mobile cellular operators are therefore looking at the unlicensed spectrum as an economical supplement to augment the capacity of their soon-to-be overloaded networks. The same unlicensed bands are luring internet service providers, venue owners, and authorities into autonomously setti...

This paper focuses on a narrow band technical solution that uses decentralized spectrum sharing to facilitate open access among competing Personal Communications Services (PCS) operators. Existing policies that apportion spectrum by Fixed Channel Assignment (FCA) involve inefficiencies resulting from fragmentation of the available resource into mutually exclusive frequency blocks. Dynamic Chann...

Spectrum resources are facing huge demands and cognitive radio (CR) can improve the spectrum utilization. Recently, power spectral density (PSD) map is defined to enable the CR to reuse the frequency resources regarding to the area. For this reason, the sensed PSDs are fused by a Fusion Center (FC) which the sensed PSDs are collected by the distributed sensors in the area. But, for a given zone...