This paper presents the application of program transformation to the development of marshaling code. Marshaling code amounts to about half of the signaling software in a subscriber radio, and as such constitutes about 20% of the total software in the radio. Development of marshaling code is considered to be a difficult, error prone, and laborious task. We have successfully developed significant portions of Motorola TETRA (Trans-European Trunked Radio) infrastructure and subscriber software through automated code generation techniques using the process outlined in this paper. This process, and the tools described in this paper, have subsequently been applied to the development of a number of communication applications and delivered tremendous cycle time and quality improvements.