  In this paper, we consider context-awareness to enhance route reliability and
robustness in multi-hop cognitive networks. A novel context-aware route
discovery protocol is presented to enable secondary users to select the route
according to their QoS requirements. The protocol facilitates adjacent relay
selection under different criteria, such as shortest available path, route
reliability and relay reputation. New routing and security-based metrics are
defined to measure route robustness in spatial, frequency and temporal domains.
Secure throughput, defined as the percentage of traffic not being intercepted
in the network, is provided. The resources needed for trading are then obtained
by jointly optimizing secure throughput and trading price. Simulation results
show that when there is a traffic imbalance of factor 4 between the primary and
secondary networks, 4 channels are needed to achieve 90% link reliability and
99% secure throughput in the secondary network. Besides, when relay reputation
varies from 0.5 to 0.9, a 20% variation in the required resources is observed.
