Development of a channel model for continuous RF frequencies in indoor environments is required for the analysis of indoor communications in an ultra wide band wireless network which includes a single transmitting and a single receiving antenna. The building blocks of such a model include single frequency propagation coefficients which are later integrated to obtain the wideband response. The model developed is in the frequency domain and thus allows analyzing dispersive effects in transmission and reflection of ultra short pulses in UWB communications from building materials which the room is made of in accordance with their complex dielectric coefficients. For this purpose a library of material characteristics of various materials (concrete, reinforced concrete, plaster, wood, blocks, glass, stone and more) in the standard frequency domain for wireless networks was assembled. In this work we will describe a model taking into account transmission through multiple layers which are a consequence of the inhomogeneity of the building materials our indoor environment is made of. Examples include hollow brick and plaster walls. Our model enables the analysis of a communication channel for both the narrow and wide band cases between adjacent rooms.  We use our model to predict UWB communications behavior and obtain a very rich and involved propagation pattern which is due to multiple reflections resulting in echoes of the narrow pulse transmitted.