LTE: How does MME knows that UE is looking for LIPA PDN connectivity ?

Question

Is there any information sent by UE to MME in Attach Request so that MME can find out the necessity of LIPA PDN connectivity ?

Answer 1

To get access to devices on a local network to which a femto is connected to, the mobile device can use a special APN. The APN tells the SGSN (UMTS) or the MME (LTE) that the mobile device wants to get a connection to the local network and not to the network operator’s core network. Optionally, a LIPA flag is defined that can be sent by the mobile device during the PDP context establishment (UMTS) or the Default Bearer activation (LTE) for the same purpose (This requires some additional software in the mobile device).

Reference: http://tech.queryhome.com/26590/lte-call-flow-to-setup-a-bearer-in-lipa-architecture