Position messages

These positions messages are sent if the bit 18 of config_flags parameter is reset

Common header	Common header	Common header	Position information data
Byte 0	Byte 1-3	Byte 4	(1)
Type=0x03	Status/Batt/Temp.	ACK / Opt	Position Information

Note

⁽¹⁾ The size of data part depends on the type of position message.

Opt: type of position message

• 0: GPS fix
• 1: GPS timeout
• 2: Encrypted WIFI BSSIDs (No more used but still supported).
• 3: WIFI timeout
• 4: WIFI failure
• 5, 6: LPGPS data (encrypted, not described in this document)
• 7: BLE beacon scan with MAC address
• 8: BLE beacon failure
• 9: WIFI BSSIDs
• 10: BLE beacon scan with short identifier
• 11: BLE beacon scan with long identifier

GPS fix payload

Common header with Type=0x03 and Opt=0x0 Position information data

Byte 5	Byte 6-8	Byte 9-11	Byte 12	Byte 13-15
Age	Latitude	Longitude	EHPE	Encrypted

Age: Time difference between the fix and the LoRaWAN transmission. Encoded form using lo= 0, hi=2040, nbits= 8, resv= 0. Expressed in seconds. The step is 8 seconds.

Latitude: Latitude of the position (expressed in degrees) is calculated as follows:

Latitude = Latitude << 8

If Latitude > 0x7FFFFFFF then Latitude = Latitude - 0x100000000

Latitude = Latitude / 10⁷

Longitude: Longitude of the position (expressed in degrees) is calculated as follow:

Longitude = Longitude << 8

If Longitude > 0x7FFFFFFF then Longitude = Longitude - 0x100000000

Longitude = Longitude / 10⁷

EHPE: Estimated Horizontal Position Error, expressed in meters. Encoded form using lo= 0, hi= 1000, nbits= 8, nresv= 0. The step is 3.9 meters.

GPS timeout payload

Common header with Type=0x03 and Opt=0x1 Position information data

Byte 5	Byte 6	Byte 7	Byte 8	Byte 9
Cause	C/N 0	C/N 1	C/N 2	C/N 3

Cause: Timeout cause

• 0: Default timeout cause (when it is not due to Cause 1 or 2)
• 1: Timeout caused by the parameter gps_t0_timeout
• 2: Timeout caused by the parameter gps_fix_timeout

C/N 0: Carrier over noise (dBm) for the first satellite seen. C/N 1: Carrier over noise (dBm) for the second satellite seen. C/N 2: Carrier over noise (dBm) for the third satellite seen. C/N 3: Carrier over noise (dBm) for the fourth satellite seen.

Notes

1. The satellites are ordered based on their C/N. The best is sent in C/N 0.
2. C/N encoding uses: lo= 0, hi=50, nbits=8, nresv= 0. It is expressed in dBm with a step of 0,2 dBm
3. Encoded form is detailed in the Encoded form section.

WIFI timeout payload

Common header with Type=0x03 and Opt=0x3 Position information data

Byte 5	Byte 6	Byte 7	Byte 8	Byte 9	Byte 10
v_bat1	v_bat2	v_bat3	v_bat4	v_bat5	v_bat6

• V_bat1: Encoded voltage at the start time (T0) of the WIFI scan.
• V_bat2: Encoded voltage at T0 + 0.5 second.
• V_bat3: Encoded voltage at T0 + 1 second.
• V_bat4: Encoded voltage at T0 + 1.5 seconds.
• V_bat5: Encoded voltage at T0 + 2 seconds.
• V_bat6: Encoded voltage at T0 + 2.5 seconds.

Notes

1. Most of time a WIFI timeout occurs due to low battery.
2. V_bat encoding uses: lo= 2.8, hi=4.2, nbits=8, nresv= 2. It is expressed in volt with a step of 5.5mV
3. Encoded form is detailed in the Encoded form section.

WIFI failure payload

Common header with Type=0x03 and Opt=0x4 Position information data

Byte 5	Byte 6	Byte 7	Byte 8	Byte 9	Byte 10	Byte 11
v_bat1	v_bat2	v_bat3	v_bat4	v_bat5	v_bat6	Error

• V_bat1: Encoded voltage at the start time (T0) of the WIFI scan.
• V_bat2: Encoded voltage at T0 + 0.5 second.
• V_bat3: Encoded voltage at T0 + 1 second.
• V_bat4: Encoded voltage at T0 + 1.5 second.
• V_bat5: Encoded voltage at T0 + 2 seconds.
• V_bat6: Encoded voltage at T0 + 2.5 seconds.

Error:

• 0: WIFI connection failure (no communication between WiFi and MCU)
• 1: Scan failure (scan of WiFi BSSID failed)
• 2: Antenna unavailable
• 3: WIFI not supported on this device

Notes

1. Most of time a WIFI timeout occurs due to a low battery condition.
2. V_bat encoding uses: lo= 2.8, hi=4.2, nbits=8, nresv= 2. It is expressed in volt with a step of 5.5mV
3. Encoded form is detailed in the Encoded form section.

WIFI BSSID payload

Common header with Type=0x03 and Opt=0x9 Position information data

Byte5	Bytes 6-11	Byte2	Bytes 13-18	Byte19	Bytes 20-25	Byte26	Bytes 27-32	Byte33
Age	BSSID0	RSSI0	BSSID1	RSSI1	BSSID2	RSSI2	BSSID3	RSSI3

Age: Encoded form of scan age with lo=0, hi=2040, nbits=8, nres=0. Expressed in seconds. The step is 8 seconds.

BSSIDx: BSSID of the WIFI station x.

RSSIx: Receive Signal Strength Indication of the WIFI station x. Non encoded form (negative value, refer to the section Two's complement Encoding for information for the encoding). It is expressed in dBm.

When long WIFI payload is activated in config_flags parameter and transmit strategy is not well chosen, too long payload could not be transmitted. In this case, after 5 discarded uplinks, the tracker sends an uplink length error message which is described here

Notes

1. The payload contains the listened WIFI stations (up to 12 if bit 12 of config_flags parameter is set, up to 4 if it is reset).
2. If less than 4 stations are listened, the payload will be reduced.
3. BSSID address is provided in big endian format. So, the byte 6 of the payload contains the MSB of the BSSID0, while the byte 11 contains its LSB.
4. The data rate and the transmit strategy must be adapted to the payload size, or the payload will be rejected by the LoRaWAN™ MAC, and won't be sent. Refer to the application note AN- 002_LoRa_Transmission_strategy for more data.

BLE beacon scan payload (MAC address)

Common header with Type=0x03 and Opt=0x7 Position information data

Byte5	Bytes 6-11	Byte2	Bytes 13-18	Byte19	Bytes 20-25	Byte26	Bytes 27-32	Byte33
Age	MACADR0	RSSI0	MACADR1	RSSI1	MACADR2	RSSI2	MACADR3	RSSI3

Age: Encoded form of scan age with lo=0, hi=2040, nbits=8, nres=0. Expressed in seconds.

MAC ADRx: MAC Address of the BLE beacon x.

RSSIx: Receive Signal Strength Indication of the BLE beacon x. Non-encoded form (negative value, refer to the section Two's complement Encoding for information for the encoding).and expressed in dBm.

Notes

1. The payload contains the listened BLE beacons (up to 4, it is configurable using ble_beacon_cnt parameter), during ble_beacon_timeout delay.
2. If less than 4 BLE beacons are listened, the payload will be reduced.
3. Refer to the application not AN-006_Position_BLE_filtering for more details

BLE beacon scan payload (short identifier)

Common header with Type=0x03 and Opt=0xA Position information data

Byte5	Bytes 6-11	Byte2	Bytes 13-18	Byte19	Bytes 20-25	Byte26	Bytes 27-32	Byte33
Age	short BID0	RSSI0	short BID1	RSSI1	short BID2	RSSI2	short BID3	RSSI3

Age: Encoded form of scan age with lo=0, hi=2040, nbits=8, nres=0. Expressed in seconds.

Short BIDx: Eddystone UID beacon: 6 last bytes of the Instance ID field Altbeacon UID beacon: 6 last bytes of the beacon UID Ibeacon UID beacon: If position_ble_report_type= 1: 6 last bytes of the Ibeacon UUID If position_ble_report_type= 3: 2 last bytes of the UUID field, the Major number and the Minor

RSSIx: Receive Signal Strength Indication of the BLE beacon x. Non-encoded form (negative value, refer to the section Two's complement Encoding for information for the encoding) and expressed in dBm.

Notes

1. The payload contains the listened BLE beacons (up to 4, it is configurable using ble_beacon_cnt parameter), during ble_beacon_timeout delay.
2. If less than 4 BLE beacons are listened, the payload is reduced.
3. Short ID is not supported for eddystone url beacons.
4. Refer to the application not AN-006_Position_BLE_filtering for more details.

BLE beacon scan payload (long ID)

Common header with Type=0x03 and Opt=0xB Position information data

Byte 5	Byte 6-21	Byte 22
Age	long BID0	RSSI0

Age: Encoded form of scan age with lo=0, hi=2040, nbits=8, nres=0. Expressed in seconds.

Long BIDx: Eddystone UID beacon: Name space + instance ID (16 bytes) Ibeacon UID beacon: 16 last bytes of the Ibeacon UUID Altbeacon UID beacon: 16 last bytes of the beacon UID

RSSIx: Receive Signal Strength Indication of the BLE beacon x. Non-encoded form (negative value, refer to the section Two's complement Encoding for information for the encoding).and expressed in dBm.

Notes

1. The payload contains the long ID of only one beacon.
2. Long ID is not supported for eddystone url beacon.
3. Refer to the application notAN-006_Position_BLE_filtering for more details.

BLE failure payload

Common header with Type=0x03 and Opt=0x8 Position information data

Byte 5
Error

Error:

• 0x00: BLE is not responding
• 0x01: Internal error
• 0x02: Shared antenna not available
• 0x03: Scan already on going
• 0x04: BLE busy (should not occur)
• 0x05: No beacon detected
• 0x06: Hardware incompatibility
• 0xFF: Unknown/wrong BLE firmware version