Review of Long Term Evolution (lte) Operations

III. 
LTE
 
NETWORK
 
PRINCIPLE
 
OF
 
OPERATIONS 
The main components of the LTE network architecture are the User Equipment (UE), the Evolved UMTS 
terrestrial radio access network (E-UTRAN), and the Evolved Packet Core (EPC). 
The EPC key components include: 
 The Mobility Management Entity (MME): This handles the session states and ensures authentication 
of a user as well as tracking a user across the network. 
 Serving Gateway (S-Gateway): This routes data packets through the access network. 
 Packet Data Node Gateway (PGW): This acts as the interface between the LTE network and other 
packet data networks [2].
These are all shown in fig. 2 [2] below. 
Figure 2: LTE Network Architecture 
LTE UEs are also known as Mobile stations (MS) or LTE data terminals or devices that are of standard 
to access the internet via 4G LTE network, such as the mobile phones, smart TVs, WiFi devices, tablets etc. 
LTE E-UTRAN consists mainly of the eNodeB (eNB), providing air interface for data traffic to and fro user 
equipment, eNodeB does several important functions such as Radio Resource Management (RRM), radio bearer 
control, radio admission control, mobility connection control, radio resource scheduling , packet compression 
and ciphering, routing of User Plane Data towards S-GW (Serving Gateway), packet scheduling and 
transmission of broadcast information and paging messages, measurement, reporting, configuration and 
reconfiguration of E-UTRAN parameters, load control, admission control etc [13]. The eNode-Bs consist of 
three major elements: The antennas, which are the most visible parts of a mobile network; Radio modules that 
modulate and demodulate all signals transmitted or received on the air interface; Digital modules that process all 
signals transmitted and received on the air interface and that act as an interface to the core network over a 
high
‐ speed backhaul connection. 
The general LTE network architecture has two parts, which are; radio network part and a core 
network part [4]. One of the complex mechanisms in the LTE network is the radio base station, referred to as 
eNode
‐ B. The name is obtained originally from the UMTS base station (Node‐ B) with an ‘e’ referring to 
‘evolved’ [6]. The UMTS radio network is referred to as the UTRAN (Universal Mobile Telecommunications 
System Terrestrial Radio Access Network), while the LTE radio network is referred to as the E
‐ UTRAN [4].
The eNode
‐ Bs consist of three major elements:
1. The antennas. They are the most visible parts of a mobile network;

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