The research community in the field of wireless communications is concerned with the modelling of concepts and the design of communication protocols. Traditionally, the applicability and the performance of these concepts and protocols are evaluated with theoretical considerations or with computer simulations. In recent years, however, the emergence of software radios facilitates their experimental evaluation in the intended application domain. In this thesis, we apply such radios to evaluate the performance of two concepts in wireless networks. The first concept is that of firefly synchronization, a bio-inspired method for synchronizing radios in a network in a completely distributed manner. We perform experiments and evaluate the performance of firefly synchronization with respect to synchronization convergence, precision and speed. The experiments show that several factors influence the performance of firefly synchronization, among which is, for example, the influence of non-homogeneous clock speeds of radios. The experiments clearly show that these non-homogeneous clock speeds limit the achievable synchronization precision. Inspired by this observation, we propose a distributed algorithm applicable to all firefly synchronization algorithms that exchange packets rather than pulses, to mitigate the detrimental effects of non-homogeneous clock speeds. Furthermore, the experiments also verify that the concept of stochastic interaction between the radios is important for achieving convergence of synchronization. A novel insight, however, is that the degree of stochastic interaction also impacts synchronization precision. The second concept is that of cooperative relaying, where a radio, called relay, helps out in transmitting data from a sender to a receiver. Many publications address the benefits of cooperative relaying from an analytical or simulative point of view. Real-world experiments and performance evaluations of cooperative relaying are, however, largely missing. To narrow this gap, we experimentally evaluate the performance of cooperative relaying in vehicular communications. Several measurement campaigns are conducted and the performance of cooperative relaying is evaluated and compared to that of time diversity, where the same data is sent twice with some time interval between the transmissions. The experiments show, that for vehicular environments with high temporal correlation of packet delivery, the duration of this time interval plays an important role in whether or not cooperative relaying outperforms time diversity in terms of packet delivery ratio.