In this lesson you will know that,

• The core network in 2G and 3G is the same. 
• It contains the SGSN which authenticates the UE and tracks its location.
• The HLR that stores subscription data for users.
• And The GGSN that connects the core network to the PDN.
• The access network in 2G contains the BTS and the BSC.
• While the access network in 3G contains the NodeB and the RNC.