Model Builder provides compatible communication across Ethernet to the latest DIS standards. It extends the full radio communication and intercom functionality of the ASTi Digital Audio Communications System (DACS) Radio and Intercom software to include any other DIS device connected to the network. Connection across the network is invisible to the user, and all radio and intercom functionality remains entirely realistic.

Installation is simple. Adding the true plug-and-play capability is achieved when installed on a trainer that has real world coordinates included in the radio model (a standard feature of the ASTi Radio).

Radios can also be attached to DIS entities simply by supplying the DIS identifier for the entity. No modification to the code controlling the entity is required.

Model Builder software provides Transmitter, Receiver, and Signal PDU (Protocol Data Unit) support for real world presentation of radio communications. Signal quality is based upon the actual physics of electromagnetic wave propagation and includes such effects as:

• Signal reception based on tune frequency comparison, signal strength, antenna gain & front end noise factor
• Signal attenuation and Noise Level based on frequency (UHF/VHF/HF) and type of transmission (AM/FM)
• Line of sight and over the horizon
• AGC and Squelch

DACS allows selection of 32 simultaneous active transmitter and receiver streams from a possible set of over 1,000 allowable radio entities on the network.

Radio objects can be located in geodetic or geocentric coordinates depending upon the user's simulation convention.

Signal PDUs provide support for both analog and digital radio systems using Mu Law, CVSD or PCM compression algorithms. Other compression algorithms can be added as the market demands. Throughout the entire system architecture, considerable effort has been expended upon hardware, software, and firmware design to minimize propagation delay effects. These can be a natural result of voice data being accumulated and then transmitted in large data packages, such as that of the DIS PDU structures. The end-to-end delay (from speaker's microphone to listener's headset) is less than 100 ms on a local area network.

One of the primary implementation features that is afforded by the ASTi total system solution is that it absolutely minimizes propagation delay by providing a direct connection between the network and the local DSP output function. This direct connection avoids the cumulative signal delay that derives from buffering at multiple stages. This is imposed by system solutions that include the radio simulation in the host where it is subject to host iteration rates and I/O buffers.

See the links in the right-hand sidebar for more information about Model Builder's capabilities.