The main goal of LTE is to provide a high data rate, low latency and packet optimized radioaccess technology.
| Peak data rate in LTE |
UL: 75Mbps(20MHz bandwidth)
DL: 150Mbps(UE Category 4, 2x2 MIMO, 20MHz bandwidth)
DL: 300Mbps(UE category 5, 4x4 MIMO, 20MHz bandwidth)
|
| Latency | End-user latency < 10mS |
| Modulation Schemes |
UL: QPSK, 16QAM, 64QAM(optional)
DL: QPSK, 16QAM, 64QAM
|
| Mobility | 350 km/h |
| Duplexing | FDD, TDD, half-duplex FDD |
The high-level network architecture of LTE is comprised of following three main components:
- The User Equipment (UE).
- The Evolved UMTS Terrestrial Radio Access Network (E-UTRAN).
- The Evolved Packet Core (EPC).
The Evolved Packet Core (EPC) (The core network)
The architecture of Evolved Packet Core (EPC) has been illustrated below.
The Home Subscriber Server (HSS) component has been carried forward from UMTS and GSM and is a central database that contains information about all the network operator's subscribers.
The Packet Data Network (PDN) Gateway (P-GW) communicates with the outside world ie. packet data networks PDN, using SGi interface. policy control decision-making, as well as for controlling the flow-based charging functionalities in the Policy Control Enforcement Function (PCEF), which resides in the P-GW.
The serving gateway (S-GW) acts as a router, and forwards data between the base station and the PDN gateway.
The mobility management entity (MME) controls the high-level operation of the mobile by means of signalling messages and Home Subscriber Server (HSS).
Functional split between the E-UTRAN and the EPC
LTE compare with 3G
| 2G/3G | LTE |
|---|---|
| UTRAN | E-UTRAN |
| SGSN/PDSN-FA | S-GW |
| GGSN/PDSN-HA | PDN-GW |
| HLR/AAA | HSS |
| VLR | MME |
The Network IDs
The network itself will be identified using Public Land Mobile Network Identity (PLMN-ID)
PLMN-ID = MCC(3digits) + MNC(2/3digits)
MCC= Mobile country code , MNC = mobile Network code
The MME IDs
MMEI = MMEC + MMEGI
MMEC is mme code
MMEGI is mme group ID.
No comments:
Post a Comment