| TRANSPORTS |
| ========== |
| |
| The Hosts and Controllers communicate over a transport, which is responsible for sending/receiving |
| HCI packets. |
| Several types of transports are supported: |
| |
| * In Process: HCI packets are passed via a function call |
| * [Serial](serial.md): interface with a controller over a serial port (HCI UART, like a development board or serial Bluetooth dongle) |
| * [USB](usb.md): interface with a controller over USB (HCI USB, like a Bluetooth USB dongle) |
| * [UDP](udp.md): packets are sent to a specified host/port and received on a specified port over a UDP socket |
| * [TCP Client](tcp_client.md): a connection to a TCP server is made, after which HCI packets are sent/received over a TCP socket |
| * [TCP Server](tcp_server.md): listens for a TCP client on a specified port. When a client connection is made, HCI packets are sent/received over a TCP socket |
| * [WebSocket Client](ws_client.md): a connection to a WebSocket server is made, after which HCI packets are sent/received over the socket. |
| * [WebSocket Server](ws_server.md): listens for a WebSocket client on a specified port. When a client connection is made, HCI packets are sent/received over the socket. |
| * [PTY](pty.md): a PTY (pseudo terminal) is used to send/receive HCI packets. This is convenient to expose a virtual controller as if it were an HCI UART |
| * [VHCI](vhci.md): used to attach a virtual controller to a Bluetooth stack on platforms that support it. |
| * [HCI Socket](hci_socket.md): an HCI socket, on platforms that support it, to send/receive HCI packets to/from an HCI controller managed by the OS. |
| * [Android Emulator](android_emulator.md): a gRPC connection to an Android emulator is used to setup either an HCI interface to the emulator's "Root Canal" virtual controller, or attach a virtual controller to the Android Bluetooth host stack. |
| * [File](file.md): HCI packets are read/written to a file-like node in the filesystem. |
