The SoR is divided into two volumes: Volume 1 presents qualitative communications requirements while Volume II provides the technical details vendors and standards development organizations need to develop the necessary technologies. The SoR was released by the Department of Homeland Security’s SAFECOM program, which focuses on the development of technology solutions for emergency responders. The SoR sets out the basic communications requirements for emergency agencies for the next 5 to 20 years. The document also provides detailed methods for measuring the performance quality of communications services provided. The key focus of SoR Volume II is on voice services, which are considered the most crucial communication mode between dispatchers, commanders, and field responders. Volume II identifies equipment factors affecting speech transmission, performance during operations, speech coding algorithms, packet size, jitter buffer size and playout algorithms, packet loss concealment algorithms, and earpiece or loudspeaker requirements. The operational factors impacting the quality of speech transmission are also identified. To determine the effectiveness of speech transmission systems referenced in SoR Volume II, 35 emergency response practitioners listened to system recordings and judged their suitability for mission-critical communications in emergency response operations. SoR Volume II also identifies performance requirements for mission-critical video services, such as ground and aerial video and tactical surveillance video. The SoR Volumes I and II identify the critical operational functions and interfaces that need continued research and development investment and standardization. Future developments identified as needed by the SoR include an integrated system of emergency response, mission-critical speech transmission, and video services. Exhibits