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Project: Opportunistic Aggregation of Spectrum and Cognitive Radios: Consequences on Public Policies

Main Objective:
Networks of the future are tending towards a diverse wireless networking world, where scenarios define that the end-user will be able to attain any service, at any time on effectively any network that is optimized for the application at hand resulting in “flexibility and choice” to enhance the quality of life of the individual, in a context of seamless interoperability and cognitive radio between network operators and access technologies, complemented by a business exploitation strategy that adapts to future economic infrastructures.

Advanced algorithms for multi-band access/selection will be explored to optimize the offered capacity whilst maintaining the user service experience acceptable. Also secondary users may have temporary opportunistic access to free spectrum ''holes'' or a set of users may simultaneously utilize, optionally, spectrum resources in lower/upper frequency bands, improving the quality of experience. The consequences of this new perspective for spectrum management in public policies will be addressed as well as the impact of having secondary spectrum markets.
From the technical point of view, modeling, simulation and experimental approaches will be followed, e.g., by using emulators with a hardware component within academic and/or industrial partnerships to be developed.

Spectrum usage optimization is one of the goals of our Project, fig. in Annex (Orlando.png). The opportunistic utilization of spectrum holes by secondary users will be investigated by implementing novel MAC designs regarding sensing cooperation and opportunistic transmission that will use cross layer and cross system information. Another objective is to attend to the increasing demand of higher data rates. Spectrum aggregation (SA) is a technique that attempts to increase spectrum utilization and it is therefore a coming solution to support the 100 MB/S over a wireless connection. After World Radiocommunication Conference 2007 (WRC07) the new bands to be considered for International Mobile Telecommunications - Advanced (IMT-Advanced) were 450-470, 698-862, 790-862, 2300-2400, 3400-4200 and 4400-4990 MHz. In order to support the increasing demand of high data rates bandwidths of 100MHz have to be considered. These bandwidths can only be achieved by going to high frequencies. The drawback of going into high frequencies is the high propagation losses and the Doppler Effect on high velocities.

Multi-hop and Infrastructural users will be managed by a Multiband Common Radio Resource Management (MB-CRRM) entity. This management will be direct in the Infrastructural case scheduling user/group of users in a given frequency and indirect in the multi-hop case (secondary users) by demanding or leaving a control channels open for secondary user coordination and taxation. The management of secondary users will be performed by making hopping frequency directives so that a dynamic coordinated secondary use of the spectrum can be made.

The MB-CRRM has the ability to optimize frequency scheduling for infrastructural users, and also frequency scheduling for secondary usage. While each system maintains control over his RRM entity, including the distributed secondary system, the MB-CRRM entity will make them more dynamic radio wise.

A wide and local MB-CRRM optimization could be differentiated. By wide MB-CRRM it is meant frequency planning for all the systems being considered in a given area considering several base stations (BSs).
Local MB-CRRM optimization addresses the integration of the distributed secondary system as well as optimization of neighboring infrastructural cells. Infrastructural wise, overall packet scheduler that will account for BSs power, available capacity, frequency will be developed.
Secondary system will follow frequency hopping directives provided by the local MB-CRRM that will be an output of the local MB-CRRM.
Parameters to be optimized involve: transmission power, frequency carrier, carrier bandwidth, control channel frequency and power, service reliability and quality.

The economic vision targets a converged network and service infrastructure for communication, computing and media applications that will create new market opportunities for 3^rd party service providers.
The drive for ubiquitous, cost-effective communication in unison with new service provisioning opportunities provided the impetus for the OPPORTUNISTIC-CR proposal. It intends to design, implement and demonstrate “cooperative networking and optimization strategies” for next generation networks that will provide a significant step towards network convergence in a truly heterogeneous environment. Multi band-common radio resource management strategies are considered, assisted by a prediction tool/algorithm that provides the future position and traffic demand of a mobile node for maximizing network resources utility and QoS delivery. By assuming a secondary usage of the spectrum, it is ensured the spectrum utility maximization. These visions will be complemented by a business feasibility study, and will include innovative graphical cellular planning tools.

Simulations (Opnet and/or ns-2 and system tools build in C++) as well as laboratory prototypes will be used for validation purposes. The team members have both WiMAX and WiFi hardware available in their institutions, where the proposed protocols, algorithms and methodologies may also be tested.
Reference: PTDC/EEA-TEL/115981/2009
Funding: FCT/PTDC
Start Date: 01-01-2011
End Date: 01-12-2013
Team: Fernando Jose da Silva Velez, Marko Beko, Rui Miguel Henriques Dias Morgado Dinis, Orlando Manuel Brito Cabral, João M. Ferro, Nuno Miguel Abreu Luís
Groups: Radio Systems – Lx
Partners: Instituto de Desenvolvimento de Novas Tecnologias (UNINOVA/FCT/UNL)
Local Coordinator: Fernando Jose da Silva Velez
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