| .. _modem: |
| |
| Modem modules |
| ############# |
| |
| This service provides modules necessary to communicate with modems. |
| |
| Modems are self-contained devices that implement the hardware and |
| software necessary to perform RF (Radio-Frequency) communication, |
| including GNSS, Cellular, WiFi etc. |
| |
| The modem modules are inter-connected dynamically using |
| data-in/data-out pipes making them independently testable and |
| highly flexible, ensuring stability and scalability. |
| |
| Modem pipe |
| ********** |
| |
| This module is used to abstract data-in/data-out communication over |
| a variety of mechanisms, like UART and CMUX DLCI channels, in a |
| thread-safe manner. |
| |
| A modem backend will internally contain an instance of a modem_pipe |
| structure, alongside any buffers and additional structures required |
| to abstract away its underlying mechanism. |
| |
| The modem backend will return a pointer to its internal modem_pipe |
| structure when initialized, which will be used to interact with the |
| backend through the modem pipe API. |
| |
| .. doxygengroup:: modem_pipe |
| |
| Modem PPP |
| ********* |
| |
| This module defines and binds a L2 PPP network interface, described in |
| :ref:`net_l2_interface`, to a modem backend. The L2 PPP interface sends |
| and receives network packets. These network packets have to be wrapped |
| in PPP frames before being transported via a modem backend. This module |
| performs said wrapping. |
| |
| .. doxygengroup:: modem_ppp |
| |
| Modem CMUX |
| ********** |
| |
| This module is an implementation of CMUX following the 3GPP 27.010 |
| specification. CMUX is a multiplexing protocol, allowing for multiple |
| bi-directional streams of data, called DLCI channels. The module |
| attaches to a single modem backend, exposing multiple modem backends, |
| each representing a DLCI channel. |
| |
| .. doxygengroup:: modem_cmux |
