Question : What are <lac>location area code, and <ci> cell ID from +CREG?

Any expert can tell me what are the and from GSM AT Command "+CREG=2"?

Does the phone receive these through cell broadcast?

If not, how the device know these information?

Thankyou!

Answer : What are <lac>location area code, and <ci> cell ID from +CREG?

Hi,

The LAC means "Location Area Code" while the CI means "Cell ID".  Basically a group of cell sites is group into a particular area called a Location Area and this is identified as a LAC.  The CI is the cell identity of the cell site serving your mobile handset.  Both the LAC and the CI are received by the mobile handset.