Xirgo Technologies Inc. XT3630F Manuel D’Utilisation
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4 SIGFOX Payload Structure
4.1 Xirgo Simple Fragmentation Protocol Specification (XSFPS)
T H I S I S A N E N C A P S U L A T E D P A Y L O A D !
In order to transmit the data efficiently we need to create an encapsulation protocol which can support
message fragmentation.
message fragmentation.
To support this, we use a Group Index and a Message Index. Each Group contains some number of Messages.
Every Message indicates the Group, the Message Index and the total number of Messages in the Group. The
Message Index indicates ordering for payload concatenation.
Every Message indicates the Group, the Message Index and the total number of Messages in the Group. The
Message Index indicates ordering for payload concatenation.
The message above “THIS IS AN ENCAPSULATED PAYLOAD!” requires 4 SigFox messages to be transmitted
assuming 2 Bytes of framing information in the fragmentation protocol.
assuming 2 Bytes of framing information in the fragmentation protocol.
One Byte is reserved for the Group which is a logical 8-bit integer that will roll over at 256 (0-255). The second
Byte is reserved for the Message Index and the total Message Count. The Lower nibble of the 2
Byte is reserved for the Message Index and the total Message Count. The Lower nibble of the 2
nd
Byte is the
Message Index within the Group and the upper nibble of the 2
nd
Byte indicates total number of messages in the
Group. ((Byte & 0x0f) + 1) == Message Index. (((Byte & 0xf0) >> 4) + 1) == Message Count. The (+1)
assumption being that there is at least one Message per Group allowing us a maximum of 16 messages per
Group and a maximum of 160 payload bytes per Group.
assumption being that there is at least one Message per Group allowing us a maximum of 16 messages per
Group and a maximum of 160 payload bytes per Group.
0 0x30 T H I S
I S
A N
0 0x31 E N C A P S U L A
0 0x32 T E D P A Y L O A
0 0x33 D !
The payload can contain any data. ASCII strings as shown above, or formatted binary data.
The data to be presented for this project:
1. Protocol Version, 1 Byte
2. Timestamp, 4 Bytes, Must be epoch as an absolute cannot fit in 4 Bytes. UNIX Epoch.
3. GPS Latitude, 4 Bytes
4. GPS Longitude, 4 Bytes
5. Accelerometer X, Y, Z, 6 Bytes
6. Temperature, Degrees F? C?, 2 Bytes
7. Light, Lux, 2 Bytes
8. Wi-Fi APs visible, 4 Max.
2. Timestamp, 4 Bytes, Must be epoch as an absolute cannot fit in 4 Bytes. UNIX Epoch.
3. GPS Latitude, 4 Bytes
4. GPS Longitude, 4 Bytes
5. Accelerometer X, Y, Z, 6 Bytes
6. Temperature, Degrees F? C?, 2 Bytes
7. Light, Lux, 2 Bytes
8. Wi-Fi APs visible, 4 Max.