CR Ad-Hoc Networks

CR ad-hoc networks face serious challenges due to (1) the time and space varying spectrum availability, (2) distributed multi-hop environment, and (3) the dynamic network topology change. These challenges require novel design techniques for several layers of the network protocol stacks. The goal of this research is not only to improve spectrum efficiency by exploiting the existing wireless spectrum opportunistically, but also to support CR-MAC protocol, spectrum-aware CR routing protocol and CR transport protocol in the cognitive radio ad-hoc networks.

● PNT Tactical Data Link based on CR/SDR Ad-hoc Network

Currently, we are researching PNT tactical data link using CR and SDR technology. PNT tactical data link has a hierarchical structure based on CR ad-hoc networks. Each communication unit coexists with secondary users and primary users through dynamic spectrum access CR-MAC protocol and exchange data in the multi-hop CR environments by exploiting CR network/transport protocols.

We are developing the CR ad-hoc network protocols and time synchronization protocol on the simulator and we implement the protocols on a CR ad-hoc network HW platform which is based on SDR. To meet the characteristics of CR ad-hoc network HW platform, which has cognitive capability and reconfigurability, we use the state-of-the-art SDR device. By using the SDR device, we can change several reconfigurable parameters to test and evaluate the PNT tactical data link prototype.