Dynamic Cross-Layer Routing Using Cognitive Spectrum Allocation Techniques
Cross Layer Routing (X-Layer)
Cognitive radio networks have emerged as a promising technology to improve the utilization efficiency of the available radio spectrum. Mainstream cognitive radio research focuses on opportunistic access to the licensed spectrum where the primary users of the band are known a priori and this knowledge can be utilized to detect if the band is occupied by the known signal pattern. However, in a highly dynamic military environment there may be multiple uncoordinated devices with unknown signal waveforms and activation statistics. In addition military environments may include hostile interference sources. Moreover, in cognitive radio networks with multi-hop communication requirements, spectrum occupancy is location-dependent, and the receiver interference profile will likely vary at each relay node.
We have developed a new spread-spectrum management paradigm, in which waveforms are designed to occupy the entire available spectrum without generating harmful interference to active primary or secondary users. In this way, the secondary users can share the licensed spectrum with the primary users to achieve frequency reuse. At the same time, the dynamic and location-dependent nature of the wireless environment required the development of routing algorithms that are aware of the interference profile at each candidate relay node.
SBIR Phase I and II program for AFRL and with U Buffalo as subcontractor, develop a joint routing and dynamic spectrum access capability for SDR networks. Algorithm is ROSA (Routing and Spectrum Access) which optimizes routing based on multiple independent network parameters including interferences, node backlogs, RF whitespace, and primary user tolerance.