A graphical cellular-modem manager — send & receive SMS, manage contacts, and switch between 4G/5G with ease.
English | 简体中文 | 繁體中文 | Русский | 日本語
ExModem uses Windows' MobileBroadband WinRT API together with Qualcomm QMI commands, aiming to push the modem capabilities of Windows to their limit.
Tested environment: Surface Pro 11 5G + a China Mobile campus data SIM + 4G / 5G networks.
As a one-person project with limited time, there may be untested scenarios or bugs. If you run into any problem, you're welcome to open an Issue!
ExModem is built with WPF-UI for a modern, fluid interface, with light / dark themes that follow the system. It ships in five languages — 简体中文, 繁體中文, English, Русский, 日本語 — and follows your system language on first launch.
View real-time status — current network, carrier, signal strength and more; switch between 4G (SMS-capable) and 5G (high-speed data) with a single click. You can also enable smart auto-switching: stay on 4G while idle to keep SMS working in real time, and automatically move up to 5G under heavy traffic for speed.
Send and receive SMS like a chat app: messages are grouped into conversations by number, with clear sent/received bubbles; verification codes are detected automatically with one-tap copy; new messages raise a system notification.
Manage both phone and SIM card contacts in one place: add, edit, delete, set avatars, and group by pinyin initial. The Messages page automatically shows the contact's name and avatar for incoming numbers.
Caution
Voice calls are not supported. The basebands in these Windows cellular devices are mostly provisioned by the vendor as data-only modules with no voice line: there is no traditional circuit-switched (CS) dialing, and voice would only work over the carrier's VoLTE/IMS — a bearer that is not exposed to apps, and the device also lacks an audio path. Therefore calls cannot be placed or received by any means. This is a hardware/firmware limitation, not something software can solve.
Contributions of any kind are welcome!
- Testing & feedback: help improve compatibility across devices / firmware / carriers.
- Report bugs: via Issues.
- Code: fork the project and open a Pull Request.
If you find this project helpful, please consider sponsoring!
Released under the GPL-3.0 license.