The communication services that are in demand by military users for tactical mobile radio systems require higher capacities than current systems can provide. The purpose of this report is to describe the possibilities with capacity enhancing techniques in tactical radio systems, as well as to point out the problems that arise when incorporating these techniques in tactical ad hoc nets. The techniques that are of interest in this context are adaptive coding and modulation, MIMO-techniques (that utilizes multiple antennas at both receiver and transmitter), and multiple-access techniques which utilizes advanced algorithms for traffic adaptivity and spatial re-use. In order to efficiently employ these techniques in ad hoc nets, substantial modifications of network protocols (e.g. scheduling of time-slots and calculation of routes) are required. Furthermore, the difficulties and necessary trade-offs on different network levels will be described in this report.