The dissemination model for information delivery has motivated an increasing interest, both in wired and wireless environments. In this model, the user subscribes the desired information and then passively receives new and filtered information. We propose a model for dissemination of information to mobile users, called dynamic channel model. It is a set of extensions to the conceptual models developed for information channels, enabling the capture of mobility-specific requirements. These are used for filtering and setting update order priorities for the information that users intend to monitor, which depends on their location and changes as they roam. This model is supported in Ubidata, an adaptable framework for information dissemination in mobile computing systems.