1# RIL Adapter<a name="EN-US_TOPIC_0000001106353742"></a>
2
3-   [Introduction](#section117mcpsimp)
4-   [Directory Structure](#section122mcpsimp)
5-   [Constraints](#section126mcpsimp)
6-   [Usage Guidelines](#section264mcpsimp)
7-   [Repositories Involved](#section279mcpsimp)
8
9## Introduction<a name="section117mcpsimp"></a>
10
11The RIL Adapter module provides functions such as vendor library loading, service interface implementation, and event scheduling and management. The module shields the differences of modems supplied by different vendors to provide a unified interface for the telephony service layer. It communicates with the telephony service layer by registering a Hardware Driver Foundation \(HDF\) service.
12
13**Figure  1**  Architecture of the RIL Adapter module<a name="fig1675210296494"></a>
14![](figures/en-us_architecture-of-the-ril-adapter-module.png)
15
16## Directory Structure<a name="section122mcpsimp"></a>
17
18```shell
19base/telephony/ril_adapter
20├── figures                             # Resource file of readme
21├── frameworks
22│   ├── BUILD.gn
23│   └── src                             # Serialized file
24├── interfaces                          # Provide internal interfaces for each business
25│   └── innerkits
26├── services                            # Service
27│   ├── hril                            # Implementation of service module APIs of the hril layer
28│   ├── hril_hdf                        # HDF service that provides initial vendor lib APIs
29│   └── vendor                          # Vendor file
30│── test                                # Test code
31│   ├── BUILD.gn
32│   └── unittest                        # Unit test code
33└── utils                               # Utilities
34```
35
36## Constraints<a name="section126mcpsimp"></a>
37
38-   In terms of software, the RIL Adapter needs to work with the HDF (drivers\_interface and drivers\_peripheral) and an interworking interface needs to be implemented by the modem vendor lib.
39-   In terms of hardware, the device must be equipped with a modem capable of independent cellular communication.
40
41## Usage Guidelines<a name="section264mcpsimp"></a>
42
43The RIL Adapter does not provide external APIs and can only be called by through drivers\_peripheral.
44
45## Repositories Involved<a name="section279mcpsimp"></a>
46
47[Telephony](https://gitee.com/openharmony/docs/blob/master/en/readme/telephony.md)
48
49**telephony_ril_adapter**
50
51[telephony_core_service](https://gitee.com/openharmony/telephony_core_service/blob/master/README.md)
52
53[drivers_interface](https://gitee.com/openharmony/drivers_interface)
54
55[drivers_peripheral](https://gitee.com/openharmony/drivers_peripheral)
56