VComm GENERIC Radio, V8 DIS Only

Object Description

The VComm GENERIC Radio, V8 DIS Only object employs a high-fidelity radio model to implement the Radio Communications protocol of the Distributed Interactive Simulation (DIS) standard (refer to the IEEE standards 1278.1a-1995, 1278.1a-1998, and 1278.1a-2xxx). This radio has input pins to control the basic functionality of any radio being modeled. However, an output pin provides a handle for the radio which can be used by several other VComm objects to enhance the run-time control of the radio, and to monitor the radio's data.

Note: Attachable objects require additional processing. It is advisable to only use attachable objects if they are needed in a given design.

For more information, refer to the VComm User Manual.

Input Pins

ANT X

ANT Y

ANT Z

Locations in the simulated DIS world are identified using a right-handed, Geocentric Cartesian coordinate system called the world coordinate system in the DIS specification. This Geocentric coordinate system is sometimes called ECEF, or Earth Centered Fixed Cartesian. The origin of the coordinate system is the centroid of the earth. The axes of this system are labeled X, Y, and Z, with the positive X -axis passing through the prime meridian at the equator, the positive Y-axis passing through 90 east longitude at the Equator, and the positive Z-axis passing through the north pole as shown. A distance of one unit measured in world coordinates corresponds to a distance of 1 m in the simulated world.

FREQ Hz

Frequency of the radio in units Hertz (Hz).

Range: Any floating point number.

VOLUME

Volume of the radio heard at the headsets.

Range: 0.0 to 1.0.

SQLCH

This radio object expects a squelch input of 0 to 1 in units of volts. This value is normally connected to a squelch control on a simulated radio. This value is internally converted to dB (log scale) so that an input value of 0 to 1 is converted and limited to a value of 0 to –100 dB.

EX ID

DIS Exercise ID.

Range: 0 to 255.

ON/OFF

Power state of the radio. Any non-zero value provides power to the radio; a value of 0 does not.

PTT

Push-To-Talk switch for radio transmissions. Any non-zero value engages radio transmission; a value of 0 does not.

Output Pin

HND

The HND pin provides a unique radio handle for this object for use by other objects (see below).

Static Data

Site Number

Application Number

Entity Number

Radio Identifier

These four single precision floating point values create a unique Entity Identifier for this radio on a DIS network. The DIS specification requires that each entity participating in a DIS exercise must have a unique site/app/entity identifier. The radio ID is provided to distinguish between multiple radios attached to a single entity (see IEEE 1278.1 DIS standard for details). V+ interprets each of the values as a 16 bit unsigned number, so only whole numbers between 1 and 65534 are valid.

If you do not need to set specific Entity Identifier for your radios, simply leave the site/app/entity/radio numbers at zero. VComm can create an automatic Entity Identifier for radios if the radio is not attached to an object that sets IDs, and if Site Number, Application Number (Host ID) or Entity Number is set to zero at startup. In this case, the computers IP address is used to establish an Entity Identifier. A computer IP address is divided into four fields called octets. VComm uses the third octet (left to right numbering) to set the Site Number and the fourth octet to set the Application Number. The Entity Number is set to one, and the Radio Identifier is set automatically based on the execution sequence (order of creation) of the radio in V+. For example, if a machine has an IP address of 192.168.1.200, the radio’s Entity Identifier would be as follows:

Site Number	1 (Third Octet)
Application Number	200 (Fourth Octet)
Entity Number	1 (Default, hard coded)
Radio Identifier	n, where n is the creation order

More about DIS Entity Identifiers:

Encoding

This parameter defines the way the signal packets are encoded before being sent over the network. The following values are valid for this parameter:

1 - µ-Law (pronounced Mew-Law), 2:1 compression

2 - CVSD per MIL-STD 188-113, 16:1 compression

3 - ADPCM per CCITT G7.21, 4:1 compression

4 - 16 bit PCM (Big Endian), 1:1 compression

5 - 8-bit Linear PCM, 1:1 compression

6 - VQ (Vector Quantization), Variable compression, (Not Supported in VComm)

7 - CVSD CCTT (bit reversed), 16:1 compression

8 - 1.625-bit GSM 06.10, Variable compression, (Currently in development in VComm)

9 - 0.7 bit GSM Half Rate 06.20, Variable compression, (Currently in development in VComm)

100 - 16-bit Linear PCM (Little Endian), 1:1 compression

255 - CVSD, 16:1 compression
(Some vendors use this for CVSD encoding)

This parameter only affects signal transmissions. Received signal packets will be properly decoded based on the transmitted encoding scheme, regardless of the setting of this parameter.

Note: The Encoding value may be changed dynamically while V+ is running and will take effect without having to stop and start V+.

Channel

(Input/Output)

This parameter designates which sound device input/output channel pair is to be used for the analog input and analog output during transmission and reception of digital voice streams.

If using an SMx system, this number is the Wave In channel for the input stream (microphone), and its corresponding Wave Out channel for the output stream (headphones).

More about Devices and Channels:

VComm Radio Control Objects

VComm Radio Monitoring Objects

Example

The figure below presents an example of a VComm GENERIC Radio, V8 DIS Only object with all of the other VComm attachable objects shown. There are two groups of attachable objects: those that control the radio, and those that monitor the radio.