DIS Transforming Radio Bridge for Windows

ASTi P/N: AW-TRB-001

The Transforming Radio Bridge (TRB) for DIS is part of ASTi's new Windows product range. TRB is designed to execute on a standard Windows XP platform, and provides capability to 'bridge' DIS PDUs between two ethernet TCP/IP subnets. In addition to the basic bridging capability, TRB also provides the capability to perform optional filtering and/or transformations back and forth between the two subnets for the following:

DIS Exercise ID
- Provides filtering on exercise ID between the two subnets
DIS PDU Type
- Provides filtering on PDU type between the two subnets
Operating Frequency
- Provides filtering capability by conditionally bridging radio family PDUs for "radios" operating at frequencies below 100,000 Hz and/or above 100,000 Hz
DIS Protocol Version
- Transforms between protocol versions 4, 5 and 6
Signal PDU Encoding Scheme
- Transforms encoding schemes with support for muLaw, CVSD, 16 bit PCM and ASTi Code 255 CVSD

TRB supports both standard TCP/IP broadcasting as well as TCP/IP multicasting.

If bridging is performed between two subnets, the subnets may be located on the same physical LAN or on two separate physical LANs. Dual LAN operation requires two separate network interfaces on the PC. Bridging may also be performed between two different UDP port numbers on the same subnet.

TRB has an extremely easy-to-use GUI interface, and configuration for the required filtering and/or bridging functionality.

In addition, the ability to simply bridge DIS PDUs between the two subnets, filtering and transformation capability may be used to do the following examples:

Reduce bandwidth requirement
If subnet 'A' is a heavily loaded 100 Mbit LAN with potentially thousands of DIS entities and hundreds of DIS Radios, and subnet 'B' is 10 Mbit LAN with a small number of radios, by use of TRB connection to subnet 'A' may be achieved for the subnet 'B' nodes without any concern for the high PDU rate on subnet 'A'.
Reduce bandwidth requirement for simulated radios
If subnet 'A' has a number of pseudo radio intercoms which need to be accessible to subnet 'B', bridging may be suppressed for all radio family PDUs for radios operating on frequencies below 100,000 Hz.
Extract PDUs for selected DIS exercises
If subnet 'A' has a very high PDU rate due to several DIS Exercises being carried out simultaneously, the TRB would be able to extract PDUs from selected DIS Exercises of interest and 'connect' subnet 'B' to subnet 'A' only for the selected exercises and thus reduce the bandwidth requirements on subnet 'B'.
Interface applications with differing DIS protocol version requirements
If a simulation site has a mixture of DIS applications that require different protocol versions, it would be possible to aggregate DIS nodes according to their protocol version requirements on two subnets, and use TRB to transform DIS protocol version between the two subnets.
Interface DIS radios with different encoding scheme requirements
If a situation exists where a number of different DIS radios must interoperate in a DIS exercise, and some of the radios have different encoding scheme requirements (for example some radios only support muLaw while some other radios only support CVSD), by aggregating the different types of radios onto two different subnets, it would be possible to use TRB to transform the muLaw encoding to CVSD and vice-versa to enable the two sets of radios to interoperate.
For after action replays where it might be required to play the recorded audio on the originating radios, a facility is provided to increment site IDs for all radio family PDUs to enable the radios to receive transmissions that they originated.

The above examples are by no means exhaustive. Other situations where the capabilities of TRB might be advantageous are limited only by the user's own imagination and ingenuity.

See also: