Dear community friends, hello!
Today, I want to share with you the structure of the E-UTRAN protocol stack.
Two planes of the E-UTRAN protocol stack.
User-plane protocol stack: transmits the number of users.
Main functions of the user plane:
Header compression
Encrypted
Dispatching
ARQ/HARQ
Control plane protocol stack: responsible for system signaling transmission
Main functions of the control plane:
Functions at the RLC and MAC layers are the same as those on the user plane.
The PDCP layer implements encryption and integrity protection.
The RRC layer implements broadcast, paging, RRC connection management, resource control, mobility management, and UE measurement report control.
The NAS layer implements core network bearer management, authentication, and security control.
S1 and X2 interfaces
S1 interface: connects the eNodeB to the EPC.
S1-MME is the control plane interface between the eNodeB and the MME.
S1-U is the user-plane interface between the eNodeB and the S-GW.
S1 interface
S1AP: The S1Application Protocol is the application layer protocol between eNodeB and MME.
SCTP: The Stream Control Transmission Protocol, ensures the delivery of signaling messages on the S1 interface between the MME and the eNodeB
GTP-U: The GPRS Tunneling Protocol, used in user plane for user data transmission between the eNdoeB and S-GW.
UDP: User Datagram Protocol, used for the user data transmission.
The data link layer can use transport-layer 2 technologies, such as PPP and Ethernet.
X2 interface: It is an interface between eNodeBs and supports the direct transmission of data and signaling.
The X2 interface is also divided into the user plane (X2-U) and control plane (X2-C). The X2-U interface is required to be the same as the S1-U, and the X2-C is required to be the same as S1-C.
This is the E-UTRAN protocol stack I want to share. Welcome to study and read.
I'll share the principles of OFDM in the next article.
