The information exchange demands for future naval communications networks could be met more easily if existing and emerging single-transceiver (ST) radios can increase spectral efficiency and network throughput by autonomously and dynamically accessing and managing the spectrum. Dynamic Spectrum Access (DSA), in which radio frequency users dynamically select available frequencies for transmission/reception from an allocated pool, or as secondary users on a not-to-interfere basis, would be useful. DSA improves network performance by reducing self-interference and boosting spectral efficiency by reducing idle bandwidths. These Innovations will boost network performance and spectral utilization, while operating in the same band as the network traffic. IAI will develop and implement a DSA system operating with ST radios on a cognitive, mobile ad hoc network (MANET). The ST-DSA system features a distributed design without a central controller. Cognitive radios will perform collective spectrum management, channel estimation, topology discovery, and transmission control to form a self-healing, multi-hop cognitive MANET. ST-DSA addresses the single-transceiver requirement along with additional restrictions on channel availability and other sensing spectrum access capabilities. It implements a complete cognitive engine that conducts collective spectrum sensing over the licensed and unlicensed spectrum to produce a near real-time spectrum map of dynamic topology structures. Radios with ST-DSA capability can utilize the spectrum map and apply a cross-layer design to access, route, and carry tactical data (voice and standard IP data) over the cognitive MANET. The transmission decisions supporting spectral agility include the selection of the next-hop neighbor, the channel or frequency band, power, rate, and traffic flow over the cognitive MANET.