Features denote the extensions of the basic function set of the communication software, while Feature Interactions (FIs) mean the unexpected interference between the features. The paper studies the FIs in the next generation communication software mainly on the aspect of the distributed implementation and deployment of the features. Based on the Communication Finite State Machine (CFSM) model, the authors design an FI detection method using the system verification technique. For the state explosion problem during verification, an optimization scheme is presented to reduce the complexity. Its validity is proved in theory and illustrated by examples.