COGNAC - COGNitive And opportunistic wireless Communication networks
The Cognitive Radio
With the rapid development of the Internet and increasing requirements from mobile users, forthcoming wireless systems are expected to provide heterogeneous multimedia services for multiple users. A fundamental problem in designing such a system is how to efficiently exploit and allocate limited radio resources among the users of the network. The spectrum is one of the most critical radio resources, whose management in future wireless communication networks will be a challenging task. Flexible spectrum use through Cognitive Radio has been identified as one possible solution to spectrum management.
Towards Cognitive Networks
The concept of Cognitive Networks means that cognitive resource management will be applied throughout the wireless networks in order to more efficiently exploit both radio and network resources. The overall goal is to enhance communication capabilities throughout the networks.
The process of cognitive resource management can be best described as a cognition cycle. The cycle includes sensing of the operating environment, management decision algorithms and adaptation to better exploit the resources in the environment. Furthermore, the decision-making has to take into account any outside restrictions and policies.
Realizing the cognitive cycle in future highly heterogeneous networks is far from being a trivial task. Key questions to be answered include how to efficiently and robustly sense the resources in the environment? Should decisions be made in a centralized or distributed manner? How can a distributed pool of resources be exploited? How can the amount of signalling involved in the cognitive cycle be minimized?
COGNAC Project
The COGNAC project covers selected fundamental issues enabling utilization of opportunistic communication systems. The project is investigating:
- Fundamental methods related to spectrum estimation and opportunistic usage.
- Radio resource management and adaptation schemes for opportunistic systems.
- Applying selected features of opportunistic systems to some existing and/or emerging communication systems to improve their performance and to extend their applicability to new application scenarios.
As a result of this project, we seek a deep understanding of the key enabling technologies for opportunistic communication systems, such as:
- Principles of flexible spectrum use, including spectrum sensing methods, policies, sensing and utilization algorithms and spatial frequency reuse in cooperative and non-cooperative scenarios.
- Dynamic system management, radio resource management and multi-channel medium access control methods.
Project Structure
Cognac is a joint project of CWC and VTT (Oulu unit). It is a 3-year project (2008-2010) in which 70% of the funding comes from TEKES (Finnish Funding Agency for Technology and Innovation).
Figure 1. Cognac concept model.
For more information:
Ph.D. Timo Bräysy, Project Manager
timo.braysy
ee.oulu.fi
gsm: +358-40-765 0002
Prof. Matti Latva-aho, Principal Researcher
matti.latva-ahoee.oulu.fi
gsm: +358-40-588 9655
