The Core component of SDL runs on a vehicle's computing system (head unit). Core’s primary responsibility is to pass messages between connected smartphone applications and the vehicle HMI, and pass notifications from the vehicle to those applications. It can connect a smartphone to a vehicle's head unit via a variety of transport protocols such as Bluetooth, USB, Android AOA, and TCP. Once a connection is established, Core discovers compatible applications and displays them to the driver for interaction via voice or display. The core component is implemented into the vehicle HMI based on a set of integration guidelines. The core component is configured to follow a set of policies defined in a policy database and updated by a policy server. The messaging between a connected application and core is defined by the Mobile API and the messaging between sdl core and the vehicle is defined by the HMI API.
The mobile library component of SDL is meant to run on the end user’s smart-device from within SDL enabled apps. The library allows the apps to connect to SDL enabled head-units and hardware through bluetooth, USB, and TCP. Once the library establishes a connection between the smart device and head-unit through the preferred method of transport, the two components are able to communicate using the SDL defined protocol. The app integrating this library project is then able to expose its functionality to the head-unit through text, media, and other interactive elements.
The SmartDeviceLink (SDL) server handles authentication, data collection, and basic configurations for SDL connected vehicles. In general these tasks are accomplished using JSON documents called Policy Tables that are configured by the server and then downloaded by other SDL components. The server's backend API (written in node.js) handles these types of requests and can be easily extended to handle more. Configuration of Policy Tables, or any other data, can be done using the server's front-end GUI (written in Angular.js). Customization of the front-end with your own look and feel is encourage and worry-free because these changes will not affect the underlying functionality of the server.
The Super Helpful Application ID (SHAID) server manages Application IDs used within the SmartDeviceLink (SDL) ecosystem. This includes creation of unique application IDs, anonymous distribution of the IDs to SDL partners, and the ability to revoke an existing ID. The SHAID server can also notify subscribing SDL Servers when an ID is revoked, allowing the SDL Server to take appropriate action.