> 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/system-information-messages/system-information-2-si2.md).

# System information-2(SI2)

Neighbour BCCH frequencies and PLMN information are sent in this SI. MS uses these frequencies for signal strength measurements required for handover.

![](https://1516040574-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fg081KOVSE5kjkOj8LvCP%2Fuploads%2F9ejow3Ee1Z7VbRlMmmqn%2Fimage.png?alt=media\&token=130605f2-4d55-4ba5-9d85-b5a4a3fbed78)

#### System Information-2 (SI2)

**System Information-2 (SI2)** is a critical broadcast message used in cellular networks. It contains essential configuration details, such as:

* Access parameters for the Random Access Channel (RACH)
* Information on the broadcast control channel (BCCH)
* Timing Advance (TA) details

This information helps devices establish and maintain communication with the network efficiently.

![](https://1516040574-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fg081KOVSE5kjkOj8LvCP%2Fuploads%2FDQQ2lhqZCnmt1Ezw3i0W%2Fimage.png?alt=media\&token=b2a086bc-c119-4877-aff7-0743c56395b1)