# A-bis interface A-bis interface connects BSC to BTS by cable or microwave links. Type of Data: 1. User Information 2. Signalling Information 3. Synchronization data 4. O\&M alarms ### TRX Signalling between BSC and BTS (TRansceiver) is the device responsible for transmitting and receiving radio signals between the BTS and the mobile devices. Each TRX handles multiple channels and is crucial for maintaining communication in a mobile network. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://gsm.learn-telecom.com/gsm-interfaces/a-bis-interface.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.