CIF: NeTS:Small:Collaborative Research:Distributed Spectrum Leasing via Cross-Layer Cooperation

CIF: NeTS: Small: Collaborative research: Distributed Spectrum Leasing

via Cross-Layer Cooperation

?Cognitive radio? networks, in which primary (licensed) and secondary (unlicensed) terminals coexist over the same bandwidth, are regarded as a promising solution to address spectral shortage and overcrowding. The main conventional approaches to enable such coexistence are: (i) Underlay/ overlay/ interweave strategies, which enforce strict constraints on the secondary behavior in order to avoid interference to the primary; and (ii) System-wide dynamic spectrum allocation. Both frameworks have significant drawbacks for implementation of large-scale distributed cognitive radio networks due to technological and theoretical limits on secondary spectrum sensing for (i) and on the stringent constraints on protocols and architectures for (ii).

To address the problems highlighted above, this research introduces and studies the novel framework of Distributed Spectrum Leasing via Cross-Layer Cooperation (DiSC) as a basic mechanism to guide the design of Medium Access Control/ Data Link (MAC/DL) - Physical (PHY) layer protocols in decentralized cognitive radio networks. According to this framework, dynamic ?leasing? of a transmission opportunity (e.g., a time-slot) from a primary node to a secondary terminal is performed locally as driven by primary needs in terms of given Quality-of-Service (QoS) measures at the MAC/DL-PHY layers. Specifically, DiSC enables each primary terminal to ?lease? a transmission opportunity to a local secondary terminal at MAC Protocol Data Unit (MPDU) granularity in exchange for cooperation (relaying). The project aims, on the one hand, at a theoretical understanding of the potentiality of the approach from the standpoints of network information theory and networking theory, and, on the other, at the (clean-slate and back-compatible) design of MAC/DL-PHY protocols that effectively implements DiSC in a complex wireless environment.

Keywords: Spectrum leasing, dynamic resource allocation, cognitive radio, cooperative transmission, cross-layer design, multi-hop wireless networks.