LTE Architecture Flashcards
EPS?
Evolved Packet System
EPS Components?
User Equipment
Evolved UTRAN
Evolved Packet Core
UE Components?
Mobile Terminal
Terminal Equipment
Universal Integrated Circuit Card
USIM?
Stores user-specific data such as
- User’s phone number
- Home network identity
Carries out various security-related calculations, using secure keys that the smart card stores
IP Support?
LTE UE Supports
- IPv4
- IPv6
- Duel Stack
A mobile receives one IP address for every Packet Data Network it is communicating from:
- Internet
- Private corporate network
What is E-UTRAN is made of?
Enhanced NodeB
Features of eNodeB?
Serving eNB
Hard Handover
Combines the functions of NodeB and RNC of UMTS
X2 Interface
Transport Network?
S1 and X2 Interfaces are not physical, rather logical interfaces.
Femto Cell
Smallest cell in LTE eNB is called Home eNB Closed Subscriber Group Home eNB Gateway S1 Interface in Femto cell
Architecture of the EPC?
Main components of the EPC
- HSS
- P-GW
- S-GW
- MME
HSS
Home Subscriber Server
P-GW
PDN Gateway
S-GW
Serving Gateway
MME
Mobility Management Entity
Home Subscriber Server?
Continued from UMTS
Central database
Contains information about all the subscribers
PDN Gateway?
EPC's gateway to the Packet Data Networks (PDN) Connects to one or more - Outside data networks - LTE Operator's servers - IP Multimedia Subsystem APN SGi
Serving Gateway?
Acts as a high-level router
Forwards data between the base station and the PDN gateway.
Mobility Management Entity?
Controls the high-level operation of the mobile
Sends signalling messages to mobiles about:
- Security
- Management of data streams
- Communicates with other elements of the network
- Using signalling messages that are internal to the EPC
One MME is responsible for?
For the mobiles in a certain geographical region
Each mobile is?
Assigned to a single MME
- Called its serving MME
- Serving MME will change if the mobile moves sufficiently far
Roaming Architecture?
Roaming allows a mobile to communicate with the Internet and the IP multimedia subsystem while visiting other network
Data traffic to PDN may go in two ways?
Home Routed Traffic
Local Breakout
Home Routed Traffic?
In which the PDN gateway lies in the home network
Local Breakout?
In which the PDN gateway lies in the visited network
