Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)

So EUTRAN, as the name suggests is a type of Radio Access Technology ( A technology that allows you to access any network remotely,of course when you are authenticated.The word radio specifies the radio waves). It is evolved from its earlier work specification that was termed as 2G and 3G respectively.

LTE E-UTRAN architecture
LTE E-UTRAN architectureLTE E-UTRAN architecture

So we can say , It is a radio access network standard meant to be a replacement of the UMTS, HSDPA and HSUPA technologies specified in 3GPP releases 5 and beyond. Unlike HSPA, LTE’s E-UTRA is an entirely new air interface system, unrelated to and incompatible with W-CDMA.

The evolved RAN for LTE consists of a single node, i.e., the eNodeB (eNB) that interfaces with the UE.


The eNB hosts the

  • PHYsical (PHY),
  • Medium Access Control (MAC),
  • Radio Link Control (RLC), and
  • Packet Data Control Protocol (PDCP) layers

What does it do? – Functions

  • user-plane header-compression and encryption.
  • Radio Resource Control (RRC) functionality corresponding to the control plane.
  • radio resource management
  • admission control
  • scheduling
  • enforcement of negotiated UL QoS
  • cell information broadcast
  • ciphering/deciphering of user and control plane data
  • compression/decompression of DL/UL user plane packet headers.

Interfaces  –

  • The eNBs are interconnected with each other by means of the X2 interface.

  • The eNBs are connected by means of the S1 interface to the EPC (Evolved Packet Core).

  • The connection to the MME (Mobility Management Entity) is termed as S1-MME and
  • the connection to the Serving Gateway (S-GW) is termed as S1-U.


The protocols used by the E-UTRAN are as follows.

User Plane

The user plane is the set of protocols that are utilized to transfer the user data from one interface to the another.The protocols utilized by the user plane are as follows which will be discussed in detail in the post.


Control Plane

(RRC) protocol terminations towards the UE

One thought on “Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)

  1. hello, can u give short but nice explaination regarding on RAN network. Basic and what actually the department do in telco’s company.thanks.i’m student.

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