Recent Patents on Computer Science - Volume 5, Issue 2, 2012

In this paper, we review some of the recent patents on spectrum sensing techniques for cognitive radio (CR) applications. The presented patents are categorized under: 1) spectrum sensing algorithms and architectures, 2) spectrum sensing and data communication and 3) cooperative spectrum sensing. The presented patents include special sensing algorithms that are based on the multi-resolution spectrum sensing (MRSS) approach, which ensures reliability of the spectrum sensing in wireless RF environments. We also discuss a CR patent that includes multiple RF chains to perform simultaneous cognitive tasks. Several patents that consider cooperative sensing are also presented as a solution to the hidden terminal problem inherent in wireless networks. We review the advantages and disadvantages of the presented patents and propose future directions for developing spectrum sensing techniques for CR’s.

Driven by the increasing demand for radio spectrum bands, it is now becoming extremely hard to find vacant bands to deploy new value added services. Spectrum shortage results from the spectrum management policy rather than from the physical scarcity of usable frequencies. Dynamic Spectrum Access (DSA) is proposed as an emerging solution to optimally use the radio resources. DSA allows secondary (unlicensed) Cognitive Radio (CR) users to access the spectrum, avoiding harmful interference with primary (licensed) users. The CR technology is a context intelligent radio capable of autonomous reconfiguration. Spectrum sensing is the enabling technology that allows cognitive radios to detect free bands (spectrum holes) and opportunistically access the radio spectrum. This paper presents an overview about the major spectrum sensing strategies, discussing some related fundamental issues and solutions. In particular, some relevant patents about this topic are discussed as well as detection strategies, current challenges and future solutions.

As the proliferation of wireless handheld devices such as laptops, smart phones, tablets grows exponentially, new technologies have to be adopted to efficiently use the Radio Frequency Spectrum. Opportunistic Spectrum Access (OSA) network offers a promising solution to improve spectrum utilization and efficiency by harnessing the available spectrum resources in real-time. However, participants in the OSA network can comprise of malicious adversaries who adopt dishonest and non-cooperative strategies to attack the network. In this paper, we focus on a critical attack on the OSA network: Primary User Emulation (PUE). In a PUE attack, the malicious adversary violates spectrum sharing etiquette by impersonating the primary user at the expense of other unselfish secondary users. We present the various strategies and countermeasures to mitigate the effects of PUE Attack. Relevant patents are also discussed.

Opportunistic Spectrum Access (OSA) is a promising solution to increase spectral efficiency in Cognitive Radio (CR) networks. According to this paradigm, unlicensed secondary CR users can access the spectrum licensed to primary users, provided that harmful interference is avoided. However, in OSA networks secondary users need a Common Control Channel (CCC) to identify the spectrum opportunities, i.e., common spectrum holes unused by primary users. To fulfill this requirement, the sharing of the spectrum sensing information via Ultra-wideband (UWB) has been proposed in the literature WRAP. In this paper, we summarize the main results we obtained on the design and dimensioning of a highly available underlay UWB signaling network. To this aim, we analyse the trade-off between the connectivity degree of a multi-hop underlay signaling network, related to the parameters of the CCC, and its coexistence with PUs. We also assess the impact of the availability and the characteristics of the CCC on the accuracy of PU detection in OSA networks. Results show that the correct dimensioning of the UWB signaling network allows to achieve high accuracy of PU detection while avoiding harmful interference. The review also discusses relevant patents on this topic.

A critical aspect in the analysis, design and implementation of wireless communication systems and networks is the thorough understanding of the nature and characteristics of the propagation medium. Its study has been a key research topic from the very beginning of wireless communications but it has proliferated in the last two decades due to the extreme growth of wireless technologies and the increasing demand of wireless services and applications. This paper identifies current trends in the modeling, simulation and estimation of the wireless propagation channel, addresses open issues in the area and discusses future research perspectives. Within this context, we provide an overview of state-of-the-art research, review selected methods and techniques in recent scientific and patent literature and present theoretical advances and underlying technologies used thereof.

The content and quality of teaching were already subjected to many theoretical researches. There is a constant need to improve the quality of education, which means better learning and teaching experience for both students and teachers. The purpose of this paper is to give basic information, and applicable examples, about methods used in communicative approach to teaching, while teaching programming. One of these methods is a project-based learning and this paper dedicates a significant part to it. The communicative approach to teaching (CAT) is based on applying the knowledge in a real context. It is achieved by optimization of the amount and retention of knowledge, and the character of subject matter, which is achieved by the higher motivation of students. The communicative approach to teaching supports the general development of instructional ability of students, independent and cooperative solving of problems and last but not least the object teaching. The centre core of CAT is created by methods which use mainly communication during classes, together with solving problems in pairs and in groups, and processes that involve the independent solving of problems. In this paper, we suggest applying the CAT method (with a partial patent description), mainly used in teaching foreign languages, to teaching programming by means of the Delphi programming language.

Word of mouth (WOM) with good information quality has a significant influence on consumer behaviors. A WOM document containing an evident sentimental orientation is one of the most important features of information quality. Although a high coverage sentimental WordNet lexicon, i.e. SentiWordNet, has been developed, its performance when applying it to WOM quality classification for WOM is not yet known. This research uses SentiWordNet for tagging sentimental orientations and classifying documents into different qualitative categories. Results from our experiments demonstrate that this proposed approach has a strong potential for use in WOM quality classification. A review outlining patents relevant to SentiWordNet is provided.

In this patent paper, a proxy blind signature scheme typed bilinear pairings is suggested. The proxy blind signature scheme is demonstrated as secure under discrete logarithm problem, decision bilinear Diffie-Hellman scheme and the chosen-target computational Diffie-Hellman in the random oracle model. In reality, users can withdraw and deposit funds from all levels of banks. In this patent we introduced a new e-payment system that uses a new proxy blind signature scheme. We claim that the proposed e-payment system can ensure that e-coins are not forged, real users remain anonymous and over-spending that can be efficiently traced. This scheme demonstrates that the combination of the proxy signature with the blind signature makes the e-payment system more robust and suitable than before. The review also discussed in the relevant patents.

The Patent s annotated in this section have been selected from various Patent databases. These recent Patent s are relevant to the articles published in this journal issue, categorized by different computation methods, bioinformatics, medical informatics, computer graphics, artificial intelligence, cybernetics, hardware architectures, software, theory and methods involved and related to computer science....