The move to 4G is a move to an Enhanced UTRAN architecture or an enhanced
3G network. the technology behing 4G is LTE standing for Long Term Evolution and
the move to 4G was an evolution to the previous 3G network.
The 4G LTE or Enhanced UTRAN comprises :
- An enhannced Node B is the transceiver controlling the air interface that
switches to the evolved Packet Core.
- The evolved packet core includes the serving gateway to control access to
Packet Gateway or Packet data Network.
- Managing the 4G network is the MME or Mobility Management Entity. This is
the core component in the 4G LTE architecture. It authenticates the mobile device
and maintains the location of this thus taking over the role of the AUC and VLR.
A HSS - Home subscriber Service provides the HLR functionality.
Additionally the MME selects for the user equipment the correct SGW to pass the
data through. Pooling of MME resources can rovide a more robust network. This part
of the network switches between the 4G network and the GSM network if phone
services are required.