Dispatch Console Interface
Each Interoperability Gateway receives and transmits packetized digital voice over an Ethernet interface for connection through a switch to the VIDA® (Voice, Interoperability, Data, and Access) network. Interoperability Gateway modules offer a 4-wire balanced line level interface for the audio connection. Audio amplitude may be adjusted under software control, and signaling lines are opto-isolated and may be operated in “open collector” mode.
When supporting interoperability with other communications systems, network users are automatically connected to legacy system users by selecting them as designated voice groups. This provides capabilities for crossband inter-system operation. Additionally, the Interoperability Gateway supports the MDC-1200 signaling format for User ID and Emergency functions.
Digital Voice Coding
Digitized voice within the digital network is coded using Advanced Multiband Excitation (AMBE®) for OpenSky systems or Improved Multiband Excitation (IMBE™) for P25 systems. AMBE/IMBE digital voice is then encapsulated into IP packets and sent along with control messages into the IP digital network. Additionally, the Interoperability Gateway supports the use of Adaptive Differential Pulse-Code Modulation (ADPCM) for NetworkFirst systems and transmission of analog inputs to other VIDA products which support ADPCM, such as the C3 MaestroIP™ and VIP Consoles.