Location solvers and device payload
Location solvers are algorithms that can be used to resolve the location of your IoT devices. AWS IoT Core Device Location supports the following location solvers. You'll see examples of the JSON payload format for these measurement types, the devices supported by the solver, and how the location is resolved.
To resolve the device location, specify one or more of these measurement data types. A single, resolved location will be returned for all measurement data combined.
Wi-Fi based solver
Use the Wi-Fi based solver to resolve the location using the scan information from Wi-Fi access points. The solver supports the WLAN technology, and it can be used to compute the device location for general IoT devices and LoRaWAN wireless devices.
The LoRaWAN devices must have the LoRa Edge chipset, which can decode the incoming Wi-Fi scan information. LoRa Edge is an ultra-low power platform that integrates a long-range LoRa transceiver, multi-constellation GNSS scanner, and passive Wi-Fi MAC scanner targeting geolocation applications. When an uplink message is received from the device, the Wi-Fi scan data is sent to AWS IoT Core Device Location, and the location is estimated based on the Wi-Fi scan results. The decoded information is then passed to the Wi-Fi based solver to retrieve the location information.
The following code shows an example of the JSON payload from the device that contains the measurement data. When AWS IoT Core Device Location receives this data as input, it sends an HTTP request to the solver provider to resolve the location information. To retrieve the information, specify values for the MAC Address and RSS (received signal strength). To do this, either provide the JSON payload using this format, or use the WiFiAccessPoints object parameter of the GetPositionEstimate API operation.
{ "Timestamp":1664313161, // optional "WiFiAccessPoints": [ { "MacAddress": "A0:EC:F9:1E:32:C1", // required "Rss":-75// required } ] }
Cellular based solver
You can use the cellular based solver to resolve the location using measurement data obtained from cellular radio towers. The solver supports the following technologies. A single resolved location information is obtained, even if you include measurement data from any or all of these technologies.
-
GSM
-
CDMA
-
WCDMA
-
TD-SCDMA
-
LTE
Cellular based solver payload examples
The following code shows examples of the JSON payload from the device that contains cellular measurement data. When AWS IoT Core Device Location receives this data as input, it sends an HTTP request to the solver provider to resolve the location information. To retrieve the information, you either provide the JSON payload using this format in the console, or specify values for the CellTowers parameter of the GetPositionEstimate API operation. You can provide the measurement data by specifying values for parameters using any or all of these cellular technologies.
When you use this measurement data, you must specify information such as the network and country code of the mobile network, and optional additional parameters including information about the local ID. The following code shows an example of the payload format. For more information about these parameters, see LTE object.
{ "Timestamp":1664313161, // optional "CellTowers": { "Lte": [ { "Mcc": int, // required "Mnc": int, // required "EutranCid": int, // required. Make sure that you use int for EutranCid. "Tac": int, // optional "LteLocalId": { // optional "Pci": int, // required "Earfcn": int, // required }, "LteTimingAdvance": int, // optional "Rsrp": int, // optional "Rsrq": float, // optional "NrCapable": boolean, // optional "LteNmr": [ // optional { "Pci": int, // required "Earfcn": int, // required "EutranCid": int, // required "Rsrp": int, // optional "Rsrq": float // optional } ] } ] } }
When you use this measurement data, you must specify information such as the network and country code of the mobile network, the base station information, and optional additional parameters. The following code shows an example of the payload format. For more information about these parameters, see GSM object.
{ "Timestamp":1664313161, // optional "CellTowers": { "Gsm": [ { "Mcc": int, // required "Mnc": int, // required "Lac": int, // required "GeranCid": int, // required "GsmLocalId": { // optional "Bsic": int, // required "Bcch": int, // required }, "GsmTimingAdvance": int, // optional "RxLevel": int, // optional "GsmNmr": [ // optional { "Bsic": int, // required "Bcch": int, // required "RxLevel": int, // optional "GlobalIdentity": { "Lac": int, // required "GeranCid": int // required } } ] } ] }
When you use this measurement data, you must specify information such as the signal power and identification information, the base station information, and optional additional parameters. The following code shows an example of the payload format. For more information about these parameters, see CDMA object.
{ "Timestamp":1664313161, // optional "CellTowers": { "Cdma": [ { "SystemId": int, // required "NetworkId": int, // required "BaseStationId": int, // required "RegistrationZone": int, // optional "CdmaLocalId": { // optional "PnOffset": int, // required "CdmaChannel": int, // required }, "PilotPower": int, // optional "BaseLat": float, // optional "BaseLng": float, // optional "CdmaNmr": [ // optional { "PnOffset": int, // required "CdmaChannel": int, // required "PilotPower": int, // optional "BaseStationId": int // optional } ] } ] } }
When you use this measurement data, you must specify information such as the network and country code, signal power and identification information, the base station information, and optional additional parameters. The following code shows an example of the payload format. For more information about these parameters, see CDMA object.
{ "Timestamp":1664313161, // optional "CellTowers": { "Wcdma": [ { "Mcc": int, // required "Mnc": int, // required "UtranCid": int, // required "Lac": int, // optional "WcdmaLocalId": { // optional "Uarfcndl": int, // required "Psc": int, // required }, "Rscp": int, // optional "Pathloss": int, // optional "WcdmaNmr": [ // optional { "Uarfcndl": int, // required "Psc": int, // required "UtranCid": int, // required "Rscp": int, // optional "Pathloss": int, // optional } ] } ] } }
When you use this measurement data, you must specify information such as the network and country code, signal power and identification information, the base station information, and optional additional parameters. The following code shows an example of the payload format. For more information about these parameters, see CDMA object.
{ "Timestamp":1664313161, // optional "CellTowers": { "Tdscdma": [ { "Mcc": int, // required "Mnc": int, // required "UtranCid": int, // required "Lac": int, // optional "TdscdmaLocalId": { // optional "Uarfcn": int, // required "CellParams": int, // required }, "TdscdmaTimingAdvance": int, // optional "Rscp": int, // optional "Pathloss": int, // optional "TdscdmaNmr": [ // optional { "Uarfcn": int, // required "CellParams": int, // required "UtranCid": int, // optional "Rscp": int, // optional "Pathloss": int, // optional } ] } ] } }
IP reverse lookup solver
You can use the IP reverse lookup solver to resolve the location using the IP address as input. The solver can obtain the location information from devices that have been provisioned with AWS IoT. Specify the IP address information using a format that's either the IPv4 or IPv6 standard pattern, or the IPv6 hex compressed pattern. You then obtain the resolved location estimate, including additional information such as city and country where the device is located.
Note
By using the IP reverse lookup, you agree not to use it for the purpose of identifying or locating a specific household or street address.
The following code shows an example of the JSON payload from the device that contains the measurement data. When AWS IoT Core Device Location receives the IP address information in the measurement data, it looks up this information in the solver provider's database, which is then used to resolve the location information. To retrieve the information, either provide the JSON payload using this format, or specify values for the Ip parameter of the GetPositionEstimate API operation.
Note
When this solver is used, the city, state, country, and postal code where the device is located is also reported in addition to the coordinates. For an example, see Resolving device location (console).
{ "Timestamp":1664313161, "Ip":{ "IpAddress":"54.240.198.35"} }
GNSS solver
Use the GNSS (Global Navigation Satellite System) solver to retrieve the device location using the information contained in the GNSS scan result messages or NAV messages. You can optionally provide additional GNSS assistance information, which reduces the number of variables that the solver must use to search for signals. By providing this assistance information, which includes the position, altitude, and the capture time and accuracy information, the solver can easily identify the satellites in view and compute the device location.
This solver can be used with LoRaWAN devices, and other devices that have been provisioned with AWS IoT. For general IoT devices, if the devices support location estimation using GNSS, when the GNSS scan information is received from the device, the transceivers resolve the location information. For LoRaWAN devices, the devices must have the LoRa Edge chipset. When an uplink message is received from the device, the GNSS scan data is sent to AWS IoT Core for LoRaWAN, and the location is estimated based on the scan results from the transceivers.
The following code shows an example of the JSON payload from the device that contains the measurement data. When AWS IoT Core Device Location receives the GNSS scan information containing the payload in the measurement data, it uses the transceivers and any additional assistance information included to search for signals and resolve the location information. To retrieve the information, either provide the JSON payload using this format, or specify values for the Gnss parameter of the GetPositionEstimate API operation.
Note
Before AWS IoT Core Device Location can resolve the device location, you must remove the destination byte from the payload.
{ "Timestamp":1664313161, // optional "Gnss": { "AssistAltitude":number, // optional "AssistPosition":[ number ], // optional "CaptureTime":number, // optional "CaptureTimeAccuracy":number, // optional "Payload": "string", // required "Use2DSolver":boolean// optional } }
