Telephony

The Fuchsia Telephony stack currently aims to provide a fast, robust, and reliable data connection over modern cellular protocols.

Source code:

• API
  • Fuchsia RIL
  • TODO: Modem Managment
• Modem Services
  • QMI RIL Service
• Drivers
  • QMI USB Driver
• Tools
  • ril-ctl

Supported Hardware:

• Sierra Wireless EM7565

Acronyms:

• FRIL - Fuchsia Radio Interface Layer
• VFS - Virtual File System

Getting Started

Setup

Telephony is not included in the core fuchsia bringup currently. You can include the bundle like in the example below:

$ fx set2 core.x64 --with //src/connectivity/telephony/

API Examples

TODO(bwb): write an example app

Tools

See the telephony/tools directory for the source code.

ril-ctl

The ril-ctl package is used for interacting with devices that expose the FRIL interface. Interactive CLIs are currently incompatible with the standard run command, so these are launched through /bin

connection owned by telephony service:

$ ril-ctl

exclusive connection to device:

$ ril-ctl -d /dev/class/qmi-transport/000

Running Tests

Host Side Tests

A large chunk of the logic of interacting with QMI based modems is generated at compile time. Tests for this live in qmigen_unittests_lib_test. You can run them on your host system with:

$ fx run-host-tests qmigen_unittests

Unit Tets

TODO(bwb): Add name of tests when they land

Architecture

QMI-based

Modem Manager watches the VFS for the qmi-usb-transport device to bind against any of the usb devices it supports. Modem manager uses a FIDL call to acquire a transport channel to the driver. It then starts a service that provides the FRIL, ril-qmi. ril-qmi proxies/translates the FIDL messages spoken to the RadioInterfaceLayer interface to vendor specific calls.

ril-ctl tool is also able to initialize and connect ril-qmi to a specified device. It will also eventually have the ability to interact with an existing ril-qmi through a management interface on the Modem Manager.

                                +----------------------+
                                |                      |
                                |     Modem Manager    +-+---+
                                |                      | |   | vfs-watcher
     +-----------------+        +----------+-----------+ |   |
     |                 |                   |             |   |
     |     ril-ctl     |                   |             |   |
     |                 |                   |             |   |
     +--------+--------+        +----------+-----------+ |   |
              |                 |                      | |   |
              +-----------------|       ril-qmi        +-+   |
                                |                      |     |
                                +----------+-----------+     |
                                           |                 |
+------------------------------------------+-----------------+--------------------+
                  Device Manager           |                 |
                                           |                 |
                               +-----------+-----------+     |
                               |                       |     |
                               |    qmi-usb-transport  +-----+
                               |                       |
                               +-----------------------+