Complex sensor network applications include multiple services, such as collection, time synchronization, and failure detection. Many of these services require local state maintenance through periodic broadcasts, which leads to high control overhead. Recent attempts to consolidate these broadcasts focus on piggybacking information into existing services, which limits code reuse and interoperability of applications. We have developed Unified Broadcast (UB) protocol that transparently combines broadcast messages from multiple protocols while maintaining a modular architecture of the network stack. UB is located between the link and network layers and it delays, schedules, and combines broadcasts from higher layer services before transmission on the wireless channel. Our empirical results show that UB can decrease the overall packet transmissions in the network by more than 60% without requiring new interfaces or affecting the correctness of the upper layer protocols.