> For the complete documentation index, see [llms.txt](https://gsm.learn-telecom.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gsm.learn-telecom.com/architecture/gsm-radio-stack/layer-2-lap-dm.md).

# Layer 2 - LAP-Dm

#### GSM Layer 2 - LAP-Dm

GSM Layer 2, or the Link Access Protocol for the Dm channel (LAP-Dm), manages the data link control in GSM networks. LAP-Dm is responsible for:

* Establishing a reliable communication link between Mobile Stations (MS) and the Base Transceiver Station (BTS).
* Handling error correction, flow control, and frame synchronization.
* Ensuring data integrity through frame acknowledgment and retransmission of corrupted frames.