The document summarizes a study on three routing protocols for mobile ad hoc networks: DSR, ZRP, and DSDV. It describes how ad hoc networks operate without fixed infrastructure and classify routing protocols as proactive, reactive, or hybrid. Proactive protocols continuously evaluate routes and maintain up-to-date network maps, while reactive protocols determine routes on demand when needed. ZRP is a hybrid protocol that takes advantages of both approaches. The document then compares the characteristics of reactive and proactive protocols and analyzes the three protocols studied in terms of these characteristics.