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ASTi Application Note 26: Using ASTi's Tactical Data Link/Data Bridge Feature
PART II
DIS Signal PDU Format
NOTE: The DIS PDU convention is to use Big Endian format.
The DIS Signal PDU is structured as follows:
| PDU Header
| 96 bits
| | Transmitter Entity ID
| 48 bits
| | Radio ID
| 16 bits
| | Encoding Scheme
| 16 bits
| | Data Link Message Type
| 16 bits
| | Sample Rate
| 32 bits
| | Length
| 16 bits
| | Samples
| 16 bits
| | Data #1
| 8 bits
| | . |
| | . |
| | . |
| | Data #n
| 8 bits |
The above fields are structured as follows:
PDU Header
| Description
| Type
| Required Value
| | Protocol Version
| 8 bit unsigned integer
| 4, 5, or 6
| | Exercise ID
| 8 bit unsigned integer
| Current DIS exercise number
| | PDU Type
| 8 bit enumeration
| 26 decimal
| | PDU Family
| 8 bit unsigned integer
| 4
| | Time Stamp
| 32 bit unsigned integer
|
| | PDU Length
| 16 bit unsigned integer
| Signal PDU size in bytes
| | Padding
| 16 bit unsigned integer
| |
Transmitter Entity ID
| Description
| Type
| Required Value
|
|---|
| Site
| 16 bit unsigned integer
| Site number of DIS machine used to transmit data
|
| Application/Host
| 16 bit unsigned integer
| Application/Host number of DIS machine used to transmit data
|
| Entity
| 16 bit unsigned integer
| Entity number of radio transmitting data
|
Radio ID
| Description
| Type
| Required Value
|
|---|
| Radio ID
| 16 bit unsigned integer
| Radio ID of radio transmitting data
|
Encoding Scheme
| Description
| Type
| Required Value
|
|---|
| Encoding Scheme
| 16 bit enumeration
| See DIS standard. First two bits identifies data class (00=voice). DACS and Telestra 4 application software uses non-zero numbers to identify non-voice data per DIS standard.
|
Data Link Message Type
| Description
| Type
| Required Value
|
|---|
| Data Link Msg Type
| 16 bit enumeration
| See DIS standard. Not used by the
DACS or Telestra 4 application software.
|
Sample Rate
| Description
| Type
| Required Value
|
|---|
| Sample Rate
| 32 bit unsigned integer
| See DIS standard. For Telestra 4 this field is used as the band rate in bits/second. Not used by the
DACS application software.
|
Length
| Description
| Type
| Required Value
|
|---|
| Length
| 16 bit unsigned integer
| See DIS standard. Data length in bits. For Telestra 4 this field is used for the data bandwidth considerations. Not used by the
DACS application software.
|
Samples
| Description
| Type
| Required Value
|
|---|
| Samples
| 16 bit unsigned integer
| See DIS standard. Not used by the
DACS or Telestra 4 application software.
|
Data #1 through #n
| Description
| Type
| Required Value
|
|---|
| Data
| 8 bit unsigned integer
| See DIS standard. Application specific data.
Not used by DACS application software.
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This space intentionally blank.
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