User's Manual

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Chapter 1 Samsung LTE System Overview
LTE eNB System Description v2.0 7
Copyright © 2017, All Rights Reserved.
Protocol Stack between NEs
The inter-NE protocol stack of the eNB is as follows:
Protocol Stack between UE and eNB
The user plane protocol layer consists of PDCP, RLC, MAC, and PHY layers.
The user plane is responsible for transmission of user data (e.g. IP packets)
received from the upper layer. In user plane, all protocols are terminated in eNB.
The control plane protocol layer is composed of the NAS layer, RRC layer, PDCP
layer, RLC layer, MAC layer, and PHY layer. The NAS layer is located on the
upper wireless protocol. It performs UE authentication between UE and MME,
security control, and paging and mobility management of UE in LTE IDLE mode.
In control plane, all protocols except for the NAS signal are terminated in eNB.
Figure 3. Protocol Stack between UE and eNB
Protocol Stack between eNB and EPC
The eNB and EPC are connected physically through FE and GE method, and the
connection specification should satisfy LTE S1-U and S1-MME interface.
In user plane, GTP-User (GTP-U) is used as the upper layer of the IP layer; and in
Control plane, SCTP is used as the upper layer of the IP layer.
The figure below shows the user plane protocol stack between eNB and S-GW: