Wireless channel models play a critical role at all stages of the development life cycle, from standards development to network deployment. Because most organized efforts to develop channel models are relatively short term and are designed mostly to support concept assessment and standards development, the distinctive needs and requirements for the channel models used at each stage of the cycle are rarely acknowledged. Here, based upon consideration of the needs and requirements for channel models across the product life cycle, we propose that such models be divided into three distinct types (I, II and III) based upon their role, generality, application, computational complexity, primary stake holders and time available to develop. We further propose that channel model development road maps be created that will allow developers concerned with particular wireless technologies and/or deployment scenarios to more effectively communicate their needs channel modelers.