Technology Overview: Access Networks (Roadmap to 4G)

Roadmap to 4G

LTE Development

LTE Target

Higher performance

100 Mbit/s peak downlink, 50 Mbit/s peak uplink

1G for LTE Advanced

Faster cell edge performance

Reduced latency (to 10 ms) for better user experience

Scalable bandwidth up to 20 MHz

Backwards compatible

Works with GSM/EDGE/UMTS systems

Utilizes existing 2G and 3G spectrum and new spectrum

Supports hand-over and roaming to existing mobile networks

Reduced capex/opex via simple architecture

reuse of existing sites and multi-vendor sourcing

Wide application

TDD (unpaired) and FDD (paired) spectrum modes

Mobility up to 350kph

Large range of terminals (phones and PCs to cameras)

LTE Architecture

LTE encompasses the evolution of:

• the radio access through the E-UTRAN
• the non-radio aspects under the term System ArchitectureEvolution (SAE)

Entire system composed of both LTE and SAE is called the Evolved Packet System (EPS)

At a high-level, the network is comprised of:

• Core Network (CN), called Evolved Packet Core (EPC) in SAE
• access network (E-UTRAN)

A bearer is an IP packet flow with a defined QoS between the gateway and the User Terminal (UE)

CN is responsible for overall control of UE and establishment of the bearers

Main logical nodes in EPC are:

• PDN Gateway (P-GW)
• Serving Gateway (S-GW)
• Mobility Management Entity (MME)

EPC also includes other nodes and functions, such:

• Home Subscriber Server (HSS)
• Policy Control and Charging Rules Function (PCRF)

EPS only provides a bearer path of a certain QoS, control of multimedia applications is provided by the IP Multimedia Subsystem (IMS), which considered outside of EPS

E-UTRAN solely contains the evolved base stations, called eNodeB or eNB

Because I am only network engineer in Telecommunication Industry, so I just keep this information to know the whole network in general. And I think someday all device will become IP (Internet Protocol), because around end of 2010, the no.1 operator in my country already started to upgrade their RAN (Radio Access Network) become IP RAN (Internet Protocol Radio Access Network) so keep prepare your self to become more faster, more reliable and more manageable. I started migration for IuPS over IP (3G) and Gb over IP (2G and 2.5G).