.. _headlabel-refx-cmd-lbs:

LBS (Location Based Services)
=============================

The `AT@LBS` command is used for auxiliary positioning.

The auxiliary positioning function consists of the following two Parts:

- **Part 1**: The terminal collects the auxiliary positioning information and reports it to the backend server.
- **Part 2**: The backend server performs calculations based on the received auxiliary positioning information to obtain the positioning point.

  Regarding **Part 1**, it is realized by the terminal, while **Part 2** is realized by the backend server.

.. note:: For the reporting of auxiliary positioning information, it is recommended to preset the 'Data ID' related to the auxiliary positioning information into :ref:`Record 50H <headlabel-refx-record-50>`. The related Data ID(s):

  - :ref:`Data 100 <headlabel-refx-data-100>` (Wi-Fi Hotspot)

.. code-block:: none

   Example:
   AT@LBS=gl601###,,1,,,,,012F$
   +ACK:LBS,123456789012345,C031,10,0,,012F,20210407101530,1234$
   AT@LBS?gl601###,,0C37$
   +QRY:LBS,123456789012345,C031,10,0,1,1,,1,,,,,0C37,20210407101530,1234$

.. tabularcolumns:: |p{2.2em}|p{7.2em}|p{5.8em}|p{19em}|p{4.8em}|

.. table::
   :width: 100%
   :widths: auto

   +-------+----------------------------------+---------------+--------------------------------------------------+--------------------+
   | Parts | Fields                           | Length (Byte) | Range/Format                                     | Default            |
   +=======+==================================+===============+==================================================+====================+
   | Head  | Header                           | 3             | AT@                                              | AT@                |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Command Word                     | 3             | LBS                                              | LBS                |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Leading Symbol                   | 1             | =                                                | =                  |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Password                         | 8-16          |                                                  | gl601###           |
   +-------+----------------------------------+---------------+--------------------------------------------------+--------------------+
   | Body  | Reserved                         | 0             |                                                  |                    |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | `Mode`                           | 1             | 0, 1, 2                                          | 0                  |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Reserved                         | 0             |                                                  |                    |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Reserved                         | 0             |                                                  |                    |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Reserved                         | 0             |                                                  |                    |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Reserved                         | 0             |                                                  |                    |
   +-------+----------------------------------+---------------+--------------------------------------------------+--------------------+
   | Tail  | Sequence Number                  | 4             | 0000-FFFF ('0'-'9', 'A'-'F')                     |                    |
   +       +----------------------------------+---------------+--------------------------------------------------+--------------------+
   |       | Tail                             | 1             | $                                                | $                  |
   +-------+----------------------------------+---------------+--------------------------------------------------+--------------------+

- `Mode`

  Specify the working mode of reporting the auxiliary positioning information.

  - **0** - Disable. The auxiliary positioning information will not be reported, that is, the data length of the 'Data ID' related to the auxiliary positioning information is always 0.

  - **1** - Enable when GNSS positioning fails. Only when the GNSS positioning fails, the data length of the 'Data ID' related to the auxiliary positioning information in the message is not 0, otherwise, it is 0.

  - **2** - Enable always. Regardless of whether the GNSS positioning is successful or failed, the data length of the 'Data ID' related to the auxiliary positioning information in the message is not 0.