SDR'12-WInnComm-Europe Papers and Tutorials
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Friday, June 29
Mapping Cognitive Radio System Scenarios into the TVWS Context *Top Paper*
Per H. Lehne (Telenor Group Industrial Development, Norway); Richard MacKenzie (BT Research, United Kingdom); Dominique Noguet (CEA LETI, France); Vincent Berg (CEA LETI, France); Ole Grøndalen (Telenor, Norway)
Cognitive Radio has been one of the key research topics in the wireless community for about 10 years. The digital switch-over in the TV bands provides opportunities for Cognitive Radio Systems (CRS) to operate in the UHF spectrum under incumbent protection restrictions. Regulation bodies, in particular the FCC and Ofcom in the UK, have specified parameters under which CRS shall operate. In this paper we analyze key scenarios for CRS stemming from the QoSMOS project. Then, we analyze how these scenarios can be mapped into the TV whitespace (TVWS) context by considering link budget computation based on FCC and Ofcom transmit power recommendations as well as statistical propagation models for the UHF band. We eventually conclude on the most promising scenarios in the context of the TVWS usage. Identifying scenarios at an early stage in system development is important as this can keep further development aligned, working with a common goal in mind. If a CRS is going to be attractive for most actors in the wireless industry, it has to provide a significant benefit compared to what is possible with today's and tomorrow's mainstream wireless technology. The scenarios identified in this paper are being used by the QoSMOS project to help guide the development of tools and techniques to bring these cognitive radio concepts closer to real-world systems. Three top criteria have been defined in order to select feasible deployment scenarios for a CRS providing both managed QoS and high mobility: "Benefit from CRS technology", "Benefit for actors", and "Managed QoS and mobility". Further, seven additional criteria have been used for targeting the most interesting and promising scenarios for business case studies. The three resulting scenarios are "Cognitive femtocell", "Cellular extension in WS" and "Cognitive ad hoc network". The analysis of how the scenarios apply to the specific case of TVWS (470-790 MHz) shows that indoor and indoor-to-outdoor short range communications is viable for the cognitive femtocell and cognitive ad hoc scenarios. Cellular extension usage is only viable for short range outdoor cells due to the secondary transmit power limitations on mobile devices imposed by regulations. On the other hand, fixed long range access can be achieved with ranges up to 8 km in suburban areas. From the FCC and Ofcom figures and link budget calculation, it can be concluded that indoor WLAN-like scenarios and fixed broadband access are the most realistic scenarios among those considered by the QoSMOS project. Extension to cellular networks is also possible, but shall focus on dense areas where cells of 1.5km are viable from a market point of view. This is typically the case where cellular system offload is required.
Opportunities of Cognitive Radio Technologies for advanced Regulatory Regimes (Presentation Only)
Eiman Mohyeldin (Nokia Siemens Networks, Germany); Maximilian Riegel (NSN, Finland)
The rapidly increasing Internet/data traffic will require additional spectrum to support the higher traffic and capacity. it is expected that new spectrum for mobile broadband will be identified in WRC2016, however from today's perspectives this will not meet the predicted demand for 2020. Thus new technologies with increased spectral efficiency and the has the potential to use the radio spectrum resources much more dynamically and efficiently will be needed. In this context, cognitive radio techniques offer improved efficiency and additional flexibility to the spectrum use. In the current studies related to Cognitive Radio, different standardization, regulation and research institutes, have identified important aspects related to the use of Cognitive Radio, cognitive technologies could be an enabler for different strategy of spectrum sharing on more dynamic basis, thus providing increased spectral efficiency of existing spectrum and mitigate the problem of congestion (e.g. capacity gain). Cognitive radio with its technologies, such as: • Sensing • Geo-location • Beacon and its possibility to be implemented in: • frequency bands that have multiple radiocommunication service allocations ( shared and opportunistic access) is anticipated to be the most suitable technology in shared spectrum access based on dynamic spectrum access. Different approaches for shared spectrum access are existing in some of the frequency bands, however they are being prompted for license exempt( e.g. TV whites space). But for mobile broadband there is need for faster access to spectrum while maintaining certain grad of quality of services. Based on these requirements ( faster access and QoS) , regulatory approaches and licensing regimes for shared spectrum access have been under study and analyses by industry and regulatory bodies. Two approaches are envisaged: • Authorized shared access (ASA) • Licensed shared access (LSA) The two approaches have common features: • Unlock the band used by incumbent ( primary user of the band) for new users • ensure predictable quality of service for all right holders • sharing agreements/ conditions among incumbent and the new users The implementation of shared spectrum access under ASA or LSA will make advantages of cognitive radio technologies. More detailed analysis and discussion on ASA/LSA and the best suited cognitive radio techniques for shared spectrum access (ASA/ LSA) will be explored in the final contribution.
- Cognitive multi-mode and multi-standard base stations: architecture and system analysis
Franco Mazzenga (Università di Roma Tor Vergata, Italy); Claudio Armani (SELEX Elsag, Italy); Alessandro Neri - Presenting (University of ROMA TRE, Italy); Romeo Giuliano (Università di Roma Tor Vergata, RadioLabs, Italy)
Each wireless technology/standard has been optimized to provide a specific set of services, in accordance to technical and economic aspects. The possibility of changing the communication technology allows the introduction of more flexible management of transmitted power and radio resources in accordance to the offered traffic, services and QoS. The adoption of multi-mode base stations (BSs) offers an additional degree of freedom for efficient usage of the radio resources. One or more radio access technologies can be activated in the single cell area in accordance to offered traffic load and service requests. Users can be distributed among the different technologies. Multi-mode BSs open new and very interesting scenarios for the development and deployment of innovative mobile access networks. In this paper we consider new access network architecture based on multi-mode BSs even including possible cooperation among different service providers. Capacity improvement due to spectrum sharing is known and shall be encouraged. It is well known that radio access systems providing spot-like coverage can be used to off-load primary mobile radio systems extending over the entire cell area. Practical examples are provided by Wi-Fi and WCDMA and femtocells. Multi-mode BSs facilitate the implementation of the off-loading concept. Achievable improvements in the case of LTE off loading UMTS are analyzed in this paper.
- Interference and Coexistence in Recovery Communications after Large Incidents (Presentation Only)
- Energy Efficiency and Fairness in Cognitive Radio Networks: a Game Theoretic Algorithm (Presentation Only)
- Improving efficiency of Genetic Algorithm based Optimizer for Cognitive Radio (Withdrawn)