Micromagnetic simulations of spin wave (SW) propagation in a permalloy film are used to extract the SW dispersion relation. The SWs are excited using the Oersted fields around a current carrying microstrip. Strong exchange interactions yield forward volume dispersion, despite using a backward volume configuration. Edge effects cause the formation of standing longitudinal waves, which manifest themselves as resonance peaks in the SW transmission spectrum. By studying the frequency separation between adjacent resonance peaks, we extract an effective exchange length for the SW excitations in the nano-stripe geometry. The interaction length is in good agreement with the values used in the simulation, thus validating the underlying theoretical approximations. The radiation resistance for the structure is also obtained from the dispersion curve. It shows a minimum at 217 GHz.