.. _location_assistance:

Location assistance
###################

The LwM2M Client sample supports a proprietary mechanism to fetch location assistance data from `nRF Cloud`_ by proxying it through the LwM2M server.
This is achieved by using LwM2M objects ECID-Signal Measurement Information object(ID 10256) and proprietary Location assistance object (ID 50001).

.. note::
   This feature is currently under development and as of now, only AVSystem's Coiote LwM2M server can be used for utilizing the location assistance data from nRF Cloud.

There are two different methods of obtaining the location assistance:

* Location based on cell information - The device sends information about the current cell and possibly about the neighboring cells to the  LwM2M server. The LwM2M server then sends the location request to nRF Cloud, which responds with the location data.
  Use :file:`overlay-assist-cell.conf` to enable this functionality in the sample.

* Query of A-GPS assistance data - The A-GPS assistance data is queried from nRF Cloud and provided back to the device through the LwM2M server. The A-GPS assistance data is then provided to the GNSS module for obtaining the position fix faster.
  Use :file:`overlay-assist-agps.conf` to enable this functionality in the sample.

Location assistance options
===========================

Check and configure the following library options that are used by the sample:

* :kconfig:option:`CONFIG_LWM2M_CLIENT_UTILS_LOCATION_ASSIST_CELL` - nRF Cloud estimates the location of the device based on the cell neighborhood.
* :kconfig:option:`CONFIG_LWM2M_CLIENT_UTILS_LOCATION_ASSIST_AGPS` -  nRF Cloud provides A-GPS assistance data and the GNSS-module in the device uses the data for obtaining a GNSS fix, which is reported back to the LwM2M server.
* :kconfig:option:`CONFIG_LWM2M_CLIENT_UTILS_LOCATION_ASSIST_EVENTS` - Disable this option if you provide your own method of sending the assistance requests to the LwM2M server.
* :kconfig:option:`CONFIG_LWM2M_CLIENT_UTILS_NEIGHBOUR_CELL_LISTENER` - Disable this option if you provide your own method of populating the LwM2M objects (ID 10256) containing the cell neighborhood information.