Research Approaches on Energy-aware Cognitive Radio Networks and Cloud based Infrastructures Nikolaos Atzarakis Department of Informatics Engineering Technological Educational Institute of Crete Heraklion, Crete, Greece [email protected] rs Name/s per Abstract—As years passes wireless networks were minimize the energy conservation, consumption rapidly improved, introducing new applications and in real time. services, as well as important challenges for mobility support. This research field is new with many researchers Section V: Cloud Computing and Resource and scientists making their proposals to optimize the Management describe the issue of resource provision of multiple services to the mobile users. In this for energy usage and internet traffic for context, this survey paper studies research approaches every device we use in our applications. from the following topics: Cognitive Radio Networks, Interactive Broadcasting, Energy Efficient Networks, Section VI: Optimization describes the Cloud Computing and Resource Management. synchronization of the moving devices in the specific regions in order to enable higher Keywords: Digital Video Broadcasting, Interleaved reliability in the availability of the requested Spectrum, TV White Spaces, Cognitive Radio Networks, resources. Digital Dividend, Dynamic Spectrum Access, Real-time Secondary Spectrum Market, Spectrum of Commons, Interactive Broadcasting, Energy Efficient Networks, Energy Consumption, Energy Conservation, Backward Traffic II. COGNITIVE RADIO Difference, Cloud Computing, Resource Management, SaaS. NETWORKS NTRODUCTION CR (cognitive radio) technology paradigm provides I. I communication that exploits efficiently radio spectrum The raise of mobility has make more needs for resources. Their technical characteristics based on interactions wireless connectivity and bandwidth. Users of wireless with the spectrum environment. They can use the un-used frequencies and efficiently access them. This opportunity networks increased as years pass and make the need for create new radio spectrum access strategies/policies. Ad-hoc more applications with less bandwidth and energy CR networks are characterized by completely self-configuring demands. In this paper we study and present related work architectures, where routing is challenging and different from categorized by topic. routing in a conventional wireless networks [1]. With this way we don’t have delay in transmission based on a signaling Section II: Cognitive Radio Networks mechanism and enabling communication between secondary provides communication that exploits nodes located in areas with different TV white spaces. Digital efficiently radio spectrum resources. technologies have created large markets which data, voice, video and audio are transmitted through wireless and wired Section III: Interactive Broadcasting networking. [2] Digital television networks have a number of proposes a network architecture that exploits additional frequencies remain unused so as to avoid causing the terrestrial digital video broadcasting interference between neighboring transmission stations. technology (DVB-T) as a complementary Secondary CR network operators gain access to unused spectrum, between primary network systems and then operate wireless backhaul/middle-mile connection. in a non-interference basis, and locations when and where it is Section IV: Energy-Efficient Networks possible for them to transmit, achieving with this way optimum include techniques that describe some ways of quality of services provided to end users. Thus providing always on triple play services utilize the digital video 1 broadcasting (DVB-T) and avoid interferences or transmission The DVB-T standard provides the ability to delay [9]. The digital broadcasting is accomplished to digital combine digital television and IP data in one UHF switch over that after the switch off a big amount of spectrum resources is free for wireless services access / provisioning [8]. channel and broadcast that to users over a wide area. Interleaved Spectrum is the large slice of “prime” broadcast Because of its broadcasting nature, protection of the frequencies, which remains unused at local level since the sensitive data transmitted encapsulated in the DVB-T analogue TV broadcasting [8]. In many areas with high terrain MPEG transport stream is needed. Without this variations and/or of low population density and dispersed areas protection any adversary can receive the data intended national TV broadcasts are either totally absent, or delivered over other medium that VHF/UHF, such as satellites. for a user by just using a laptop and a DVB-T receiver Effectively, in these areas the unexploited VHF/UHF spectrum card with appropriate software [26]. is very large, often comprising the entire TV Spectrum. Such Furthermore, television radio spectrum, which is a geographical White Spaces of TV coverage can be found in rural areas, which tend to be underserved with other broadband range of low frequencies in VHF and UHF bands, is options such as Digital Subscriber Line (DSL) or cable. There traditionally used exclusively by analogue television are techniques that use those frequencies as (DSA) Dynamic broadcasters [7]. Spectrum Access , Spectrum Commons and Spectrum Markers There is a global move to switch over from [8]. analogue to digital television. This is called digital switchover (DSO), or in some cases, the analogue switch (ASO), referring to III. INTERACTIVE the time when digital terrestrial broadcasting begins, or when analog broadcasting ends, respectively [7]. BROADCASTING Some of the spectrum bands used for analogue television will be totally cleared and made available for usage by other wireless networks. Market analysis Information and communication technologies shows that the “digital dividend” is a unique (ICT) enable a large number of users worldwide. A opportunity to realize economic/social benefits across lot of companies try have communication with their countries [7].The transmission from analog to digital customers via phone e-mail or internet network. In will free valuable spectrum to increase reliability and our days it is a tactic in marketing that internet and efficiency broadcasting. worldwide networks have a specially connection There is another one technique called DVB/IP between them. backhaul environment that enables users to access Interactive marketing allows a company to use triple-play IP services at a guaranteed QoS. Users direct response to build a relationship with customers receive/deliver triple-play IP-services via intermediate [32]. communication nodes, which make use of Marketing is the process used to determine or wired/wireless technologies in the access network. services customers are interested in and the strategy of Nowadays, backhaul networks are mainly based on what policy should have that the customers be wireless technologies (e.g. Microwave), providing for satisfied. the fast deployment of broadband metropolitan networking infrastructures within any terrain, besides One of the most development techniques in reducing the high installation costs usually required nowadays is DVB-T. DVB-T is a standard for the for a wired/cable backhaul connection [30]. transmission of digital TV programs [33]. It is very important cause in our days many applications uses It proposes a network architecture that exploits that standard like e-banking and they demand security the terrestrial digital video broadcasting technology sensitive information transmission and storage them (DVB-T) as a complementary wireless [33]. backhaul/middle-mile connection. DVB-T technology is not only used for delivering custom People use more TV set for relax or to forget their linear content (i.e. one -way services) but also as a routine and get rest. In such case DVB-T have data traffic through several interaction channels [32]. 2 medium for the provision of interactive multimedia application start up minimizing the GPU/CPU and on-demand services [30]. efforts and the energy of the device is running out of resources. For the Backward Traffic Difference structure follows Section II describes the related work done IV. Energy-Efficient and the need in adopting a Traffic-based scheme, and then Section III follows by presenting the Networks proposed. Backward Traffic Difference estimation for Energy Conservation. Section IV presents the real time performance evaluation results focusing on As years passes global industrial applications and the behavioral characteristics of the scheme and devices (personal computers, mobile, smart- the Backward Traffic Difference along with the phones, tablets) become more efficiency and system’s response, followed by Section V with more usefully created a new field that propose the conclusions and foundations, as well as mechanisms, which consider the energy potential future directions. consumption of the wireless devices, while For the “low offered” throughput model running an application. This make the need for a related work and the research motivation are dependable mobile computing processing described in Section II. Section III proposed environment. These devices while are in use of offloading scheme and the associated mechanisms sharing resources and data loss their network to reduce the energy consumption, maximizing connectivity as they moved. Therefore, a the lifetime of the devices. Section IV presents mechanism that faces the connectivity problem the results that were obtained, by conducting and enables the devices