lte epc ieee comsoc rao april 8 2010

7/30/2019 Lte Epc Ieee Comsoc Rao April 8 2010

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Motorola General Business

Mobile Broadband Evolution LTE and EPC

Srini RaoSrini Rao

Fellow of Technical StaffFellow of Technical Staff

Motorola Enterprise Mobility SolutionsMotorola Enterprise Mobility Solutions


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Agenda

LTE Timeline Overview

Applications

EPC Overview Interworking and mobility

3GPP access

Non-3GPP access QoS and Policy Roaming Voice over LTE

CSFB, VoLGA, IMS VoIP/One Voice, over the top Voice Handover

Future Directions LTE-Advanced

Summary


Srini Rao LTE EPC IEEE ComSoC Boston April 8, 2010 2


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LTE Timeline

2005 2009 2010 20122006 2007 2008 2011

Trials

First LTE LaunchTeliaSonera

Trials

Deployments

StandardsRel 8

LTE / EPCRel 9Rel 6

HSPA

Rel 7HSPA

+Rel 10

LTE - Advanced

Verizon target sLTE Launch in

30 Markets

AT&T trials in2010, Initial

deployment in2011

59 LTE Network commitments in 28 countries around the world GSA Mar 2010

China Mobile trials TD-LTE in 2010




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Terminology

Long Term Evolution (LTE)

3GPP (Third Generation Partnership Project) work item known as LTE

Evolution of GSM/GPRS, WCDMA/HSPA radio networks

LTE strictly refers to air interface, often entire technology (including corenetwork) loosely referred to as LTE (or LTE/SAE)

Evolved Packet Core (EPC)

Outcome of 3GPP work item - System Architecture Evolution (SAE)

Evolve GPRS and HSPA packet core networks to an all-IP based core

Other terms

Evolved UTRAN (E-UTRAN)

Radio access network is referred to as E-UTRAN

Evolved Packet System (EPS) End-to-end system including LTE terminals, E-UTRAN, and Core network




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LTE Drivers

UMTS-HSPA Voice and Data Traffic1

Explosive growth in mobile data traffic Rise in adoption of broadband wirelessdevices

Smart phones, modems, integratedPCs/Laptops

Popularity of video, apps

Flat rate data plans

Need for improved cost efficiency Expected cost per Mbps on HSPA is 14% of coston EDGE, and LTE would be 3% of EDGE cost2

Cost per MB expected to drop from 0.06 for

WCDMA to 0.03 for HSPA and 0.01 for LTE(2x5 MHz)3

Source: Dr. Klaus-Jurgen Krath, T-Mobile International

1. Source: HSPA to LTE-Advanced, Rysavy Research / 3G Americas, Sep. 2009

2. Kris Rinne, SVP Architecture and Planning, AT&T, 4G World, Sep. 20093. Source: Analysys Mason, 2008, from UMTS Forum white paper Feb. 2009




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Key LTE Target Requirements1

Peak data rates (for 20 MHz, 1 Tx and 2 Rx antennas at terminal) 100 Mbps downlink (DL) 50 Mbps uplink (UL)

Improved spectral efficiency (in bits/s/Hz)

3-4 times higher than HSPA (3GPP Release 6) DL 2-3 times higher than HSPA UL

Reduced latency User plane latency (one way radio delay) < 5 ms Control plane latency (idle to active) < 100 ms

Spectrum and bandwidth flexibility for deployment Channel bandwidths 1.4, 3, 5, 10, 15 and 20 MHz, asymmetric allocation

(different UL, DL BWs) Support both paired and unpaired spectrum (FDD and TDD modes using

common air interface) Cost efficiency Simpler all-IP flat architectures, Self-Organizing Network (SON) capability etc.

to reduce CAPEX and OPEX

1. From 3GPP TR 25.913




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LTE Radio Interface

From UMTS Long Term Evolution (LTE)Technology Introduction, Rohde &Schwarz, Sep 08

Multiple access scheme

OFDMA DL SC-FDMA UL

Similar to OFDMA, more power efficient lower peak-to-average power ratio

Adaptive Modulation and Coding

DL/UL QPSK, 16QAM, 64QAM Convolutional and Turbo codes

MIMO Spatial multiplexing

(2 or 4)x(2 or 4) DL and UL

Multi-user MIMO Peak rates up to 300/75 Mbps DL/UL for 4x4 MIMO

LSTI (LTE/SAE Trial Initiative)

10 operators in trials Peak rates for FDD and TDD normalized to 20

MHz > 100 Mbps DL, 30 50 Mbps UL

Measured end-endround trip latencies < 30 ms

Verizon trial (10 MHz FDD)

Average rates 5-12 Mbps DL, 2-5 Mbps UL, peak rates 40-50 Mbps DL, 2025 Mbps UL

No. of Resource blocks ranging from6 (1.4 MHz) to 100 (20 MHz)




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LTE Frequency Bands

TDD2400 MHz2300 MHz2400 MHz2300 MHz40








...

FDD746 MHz734 MHz716 MHz704 MHz17




FDD1495.9 MHz1475.9 MHz1447.9 MHz1427.9 MHz11


FDD1879.9 MHz1844.9 MHz1784.9 MHz1749.9 MHz9




FDD894MHz869 MHz849 MHz824 MHz5





DuplexMode

Downlink (DL) BS transmitUplink (UL) UE transmitOperating

Band

From 3GPP TS 36.101

Verizon to deploy LTE in 700 MHz spectrum (10 + 10 MHz in Band class 13)

AT&T to deploy LTE in 700 MHz and AWS spectrum (Band class 4)

2.6 GHz TDD band being added in U.S. for Clearwire




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LTE Enables New Applications

HD Video Streaming

(720i H264)

DL 6-8Mbps

DL Data Rate



Video Blogging / Live video

UL SD-2Mbps / HD-6-8Mbps

UL Data RateLatency

MMOG (OnlineGaming)


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Evolved Packet Core

(EPC)




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Why is Core Evolution needed?

2G/3G mobile core networks designed for low-speed, best-effort data Increased scalability of core elements to handle significant increase in

number of connections, bandwidth, and mobility High throughput and low latency requirements Key aspects of EPC

All-IP flat network architecture Separation of control and data planes End-to-end QoS management and service control through policy control and

charging (PCC) architecture

No circuit-switched core Support for multiple access networks

Not covered Protocol alternatives for S5/S8 interface GTP versus PMIPv6 assuming GTP

primarily for simplicity Related topic of on-path versus off-path policy Security authentication, authorization, etc. Charging




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2G/3G to LTE

Access Packet Core Services

GSM/GPRS

BTS BSC MGW

Circuit Core

MSC ServerWCDMA/HSPA

Node B

LTE/SAE

eNodeB

MME

RNC

Serving GW

PDN GW

SGSN

GGSN

PSTNPSTN

IPNetworks(IMS, Internet

etc.)

IPNetworks(IMS, Internet

etc.)




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Network Architecture Overview

UE

MME

HSS

Serving

GW

PDN

GW

PCRF

IP Networks(IMS, Internet etc.)


S6a

S11

S1-U

S1-MME

LTE-Uu S5

Gx

Rx

SGi

eNB

S10

X2

Mobility Management Entity

Key control and Signaling Element Gateway Selection

Idle state terminal location management

Bearer control

Home Subscriber Server

User subscription data

Policy and Charging Rules

Function Gating and QoS policy control

Flow-based charging control

Serving Gateway

Bearer plane element interfacing

E-UTRAN

Mobility anchor for inter-eNB andinter-3GPP access mobility

Packet Data Network (PDN) Gateway

Bearer plane element interfacing PDNs

Terminal IP address allocation

Policy enforcement

Packet filtering

Charging

Evolved Node B

Radio Resource Management

User plane IP header compressionand encryption




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UE

MME

SGSN

HSS

Serving

GW

PDN

GW

PCRF

IP Networks

(IMS, Internet etc.)


WCDMA/HSPA

WCDMA/HSPA

GSM/GPRS

GSM/GPRS

S6a

Gr

S1-U

S1-MME

LTE-Uu S5

Gx

Rx

SGi

Gn

eNB

S10

X2

Interworking and Mobility 3GPP Access (Gn/Gp SGSN)

S12

Gn

S11

Handovers to/from 2G/3G similar to inter-SGSN handover with

MME acting as an SGSN

PDN GW acting as a GGSN

SGSN must select a PDN GW for LTE capable terminals in 2G/3G

Model applicable for GTP based S5/S8 interface

HSS needs to support or interwork with Gr interface

Direct tunnel support via S12 interface for 3G




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UE

MME

SGSN

HSS

Serving

GW

PDN

GW

PCRF

IP Networks

(IMS, Internet etc.)


WCDMA/HSPA

WCDMA/HSPA

GSM/GPRS

GSM/GPRS

S6a

S4

S1-U

S1-MME

LTE-Uu S5

Gx

Rx

SGi

S3

eNB

S10

X2

Interworking and Mobility 3GPP Access (S4 SGSN)

S12

S11

Addition of new S3 and S4 interfaces Support for Idle mode Signaling Reduction (ISR)

Enables EPC-only core for all 3GPP accesses, including ability to handover betweenand within 2G & 3G radio networks

Direct tunnel support via S12 interface for 3G



I ki d M bili GPP A


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Interworking and Mobility non-3GPP Access(Optimized Handover for HRPD/EV-DO)

HRPD High Rate Packet Data

AN Access Node

HSGW HRPD Serving GW

AAA Authentication,Authorization, Accounting

LTE-UuUE

MME

HSS

Serving

GW

PDN

GW

PCRF



S6a

S11

S1-U

S1-MME

S5

Gx

Rx

SGieNB

AAA

HRPDAN

HSGW

S101S103

IOS

S2a

STa

SWx

S6b

Optimized handover supported in both idle and active states and E-UTRAN to/from HRPD

Common user subscription data in HSS Terminal in E-UTRAN receives HRPD system info on broadcast channel or via dedicated signaling Pre-registration (and handover signaling) using S101 interface PDN GW acts as a common IP anchor point User data between HSGW and PDN GW transported over S2a interface supporting PMIPv6

Serving GW forwards packets destined to terminal via S103 interface to HSGW



I t ki d M bilit N 3GPP A (G i )


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Interworking and Mobility Non-3GPP Access (Generic)

LTE-UuUE

MME

HSS

Serving

GW

PDN

GW

PCRF



S6a

S11

S1-U

S1-MME

S5

Gx

Rx

SGieNB

TrustedNon-3GPP(WiMAX,CDMA)


S2a

STa

SWx

UntrustedNon-3GPP(WiFi etc.)


ePDG

SWa

S6b

S2b

SWn

AAA

SWmePDG evolved Packet Data Gateway

Trusted (e.g. WiMAX, CDMA) versus untrusted (e.g. public WiFi) Non-3GPP networks Trusted access networks connect to PDN GW via S2a similar to optimized HRPD For untrusted networks, terminal connects to ePDG using IPSec tunnels

ePDG interfaces to PDN GW via S2b using PMIPv6 Network based versus client based mobility

For client based mobility, terminal connects to PDN GW via S2c interface (not shown) using DSMIPv6or MIPv4



Q S C t


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QoS Concepts

EPS Bearer is a logical aggregate of one or more IP flows IP flows (aka service data flows or SDFs) may belong to one or more

services

EPS Bearer provides connectivity to Packet Data Networks (PDNs) Bearer extends from UE to PDN GW

All Service data flows within a bearer receive same level of QoS

Default bearerestablished when UE connects to a PDN

Remains in place as long as the PDN connection is alive

Provides UE with low latency always-on IP connectivity to PDN

QoS level of default bearer assigned based on subscription

Dedicated bearersare setup when new IP flows that require specificpacket forwarding treatment are started

Dedicated bearers can be Guaranteed Bit Rate (GBR) or non-GBR

Default bearer is always non-GBRMotorola General Business


EPC B M d l (GTP b d S5/S8)


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EPC Bearer Model (GTP based S5/S8)

PDN GW

Service Data Flows

eNBUE

Service Data Flows

UL Packet Filter

Radio Bearer S1 Bearer

Application / Service Layer

S5/S8 Bearer

S GW

DL Packet Filter



QoS Parameters


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QoS Parameters

QoS Class Identifier (QCI) A scalar value mapped to specific bearer

level packet forwarding treatment e.g. scheduling weights, queuemanagement thresholds, link layerprotocol configuration etc.

9 standardized values of QCI defined Each bearer assigned one and only oneQCI

Allocation and Retention Priority (ARP) Decision to accept or reject due to resourcelimitations (typically GBR bearers)

Decision (e.g., by eNB) which bearer(s) todrop (e.g. at handover)

Guaranteed Bit Rate (GBR) and MaximumBit Rate (MBR)

Apply to GBR bearers In Release 8, MBR equals GBR

Aggregate Maximum Bit Rate (AMBR) APN-AMBR total bit rate allowed for auser for all non-GRR bearers associatedwith an APN (Access Point Name)

UE-AMBR total bit rate allowed for a userfor all non-GRR bearers separate UL and DL values of AMBR

QCI Resource

Type

Priority Packet Delay

Budget

Packet Error

Loss Rate

Example Services

1 2 100 ms 10-2 Conversational Voice

2 GBR 4 150 ms 10-3 Conversational Video (Live Streaming)

3 3 50 ms 10-3 Real Time Gaming

4 5 300 ms 10-6 Non-Conversational Video (Buffered Streaming)

5 1 100 ms 10-6 IMS Signalling

6 6 300 ms 10-6 Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file

sharing, progressive video, etc.)

7 Non-GBR 7 100 ms 10-3 Voice, Video (Live Streaming), Interactive Gaming

8 8 300 ms 10-6 Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file

9 9 sharing, progressive video, etc.)

From 3GPP TS 23.203



Policy and Charging Control (PCC) PCRF Policy and Charging Rules Function


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Policy and Charging Control (PCC) PCRF Policy and Charging Rules FunctionPCEF Policy and Charging Enforcement Function

SPR Subscription Profile Repository

AF Application Function

OFCS Offline Charging System

OCS Online Charging System

PCEF

PDN GWUE

MME

HSS

ServingGW

PCRF



S6a

S1-U

S1-MME

LTE-Uu S5

Gx

Rx

SGi

S3

eNB

S10

X2

SPR

Sp

AF

OCS

OFCS

Gy

Gz

S11

Policy control

gating control allow or block IP flows

QoS control provide authorized QoS (eg. QoSclass, bit rates etc.) decision to PCEF whichenforces it

Charging control online and offline

PCC rule includes SDF template, precedence, gatestatus, QoS control info (QCI, ARP, bit rates etc.),

charging control info

PCC enables a centralized mechanism forservice-aware QoS and charging control

PCRF controls dynamic policies based on

subscription info from SPR, Session info fromAF, operator provisioned policies, accessnetwork info from PCEF etc.

alternatively, static policies can also beprovisioned in PCEF



Policy Control Use Case for IMS Voice


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Policy Control Use Case for IMS Voice

PCEF

PDN GWUE

MME

HSS

ServingGW

PCRF



S6a

S11

S1-U

S1-MME

LTE-Uu S5

Gx

Rx

SGi

S3

eNB

S10

X2

SPR

Sp

AF(P-CSCF)

OCS

OFCS

Gy

Gz

4. PolicyDecision

6. Bearerbinding

1. Application Signaling (SIP/SDP)

2. App Info

3. Subscription Info

5. PCC rule

6. Activate / modify bearer



Network Architecture for Roaming (Home Routed)


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Network Architecture for Roaming (Home Routed)

LTE-UuUE

MME

HSS

ServingGW

PDNGW

hPCRF

IPNetworks

(IMS,Internet)

IPNetworks

(IMS,Internet)

S6a

S11

S1-MME

S8

Gx

Rx

SGi

S1-UeNB

Trusted

Non-3GPP(WiMAX,CDMA)

TrustedNon-3GPP

(WiMAX,CDMA)

S2a

STa

SWx

Untrusted

Non-3GPP(WiFi etc.)


ePDG

SWa

S6b

S2b

SWn

SWm

vPCRF

S9

GxbGxcAAA

Proxy

SWd

Gxa

AAA

Home Network

Visited Network

Serving GW in visited network and PDN GW in home connected via S8 interface All traffic for the terminal IP connection routed via home network

No direct policy control across home/visited network boundary Only through interaction between home PCRF and visited PCRF via S9 interface vPCRF may accept or reject (not modify) policy decisions made by hPCRF

If S8 is based on GPRS Tunneling Protocol (GTP), vPCRF and S9 are not required



Network Architecture for Roaming (Local Breakout)


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Network Architecture for Roaming (Local Breakout)

LTE-UuUE

MME

HSS

ServingGW

hPCRF

IPNetworks

IPNetworks

S6a

S11

S1-MME

S5

Gx

Rx

SGi



S1-UeNB


Trusted

Non-3GPP(WiMAX,CDMA)

S2a

SWx


STa


ePDG

SWa

S6b

S2b

SWn

SWm

S9

GxbGxc

SWd

Gxa

AAA

Home Network

Visited Network

Rx

Visited IPNetworks

Visited IPNetworks

AAAProxyPDN

GW

vPCRF

Both Serving GW and PDN GW in visited network Traffic routed from terminal to IP network directly

Application Function (AF) may be in Home or Visited network If AF is in visited network, Rx signaling transported to home PCRF via visited PCRF

using S9 interface

Voice Options for LTE


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Voice Options for LTE

LTE/SAE networks have no circuit core

Initial roll-outs likely will support data only devices such as

USB dongles

Voice based on legacy circuit core

CS (Circuit Switch) Fallback (CSFB)

Voice over LTE via Generic Access Network (VoLGA)

Voice based on IMS

3GPP Multimedia Telephony (MMTel) / One Voice Over the top VoIP



Circuit Switch Fallback (CSFB)


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Circuit Switch Fallback (CSFB)

Use legacy CS domain for voice in 2G/3G(GSM, WCDMA, CDMA1x)

MSC upgraded to interface with EPC new SGs interface with MME for GSM/WCDMA

S102 interface between MME and 1x InterworkingSolution (1xCS IWS) for CDMA

paging request delivered via LTE

paging response etc. and call originations via2G/3G

Feature in 3GPP Rel 8 standard Supported by NTT DoCoMo, KDDI and others

Optimizations to address call setup delays in Rel 9(for CDMA) and Rel 10 for GSM/WCDMA

CSVo

ice

CSVo

ice

Signaling

EPC

2G/3G

Core

SGs

MSC

MME

Suitable for initial stages of LTE deployment prior to IMS introduction

Dual RX terminal alternative to new interface requirements SMS also supported over LTE using the interfaces with 2G/3G MSC

No fallback to 2G/3G needed

Handover of concurrent LTE data sessions depend on 2G/3G network capability



Voice over LTE via Generic Access (VoLGA)


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Voice over LTE via Generic Access (VoLGA)

Based on 3GPP UMA/GAN standardfor voice over WiFi

VoLGA Access Network Controller

(VANC) is a modification of GANC

CS signaling and bearers tunneledover IP

Developed in VoLGA Forum, not a

3GPP standard Driven by T-Mobile

VoIP

EPC

2G/3GCore

MSC

VANCCS Voice



IMS based VoIP (MMTel / One Voice)


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IMS based VoIP (MMTel /One Voice)

SIP based VoIP for terminals in LTE usingIMS Multimedia Telephony (MMTel)standard

Support for voice call handover to CS

domain in 2G/3G for broader coverage Single Radio Voice Call Continuity (SR-VCC)

One Voiceprofile defined to promote astandardized solution for initial

deployment of cellular IMS based VoIPnetwork

Supported by several Operators includingAT&T and Verizon

VoIP

EPC

2G/3GCore

MSC

MME

IMS



Voice Handover Mechanisms


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Voice Handover Mechanisms

Single Radio Voice Call Continuity(SRVCC)

VoIP call on LTE to circuit voice call onGSM, WCDMA or CDMA 1x

Enhanced MSC server with Sv interfaceto MME in GSM/WCDMA

1xCS Interworking Solution (1xCS IWS)

in CDMA1x with S102 interface to MME Call anchored on IMS (SCC-AS)

Network layer mechanism

VoIP

EPC

2G/3G

Core

Sv

MSC

MME

IMS

CSVoic

e

CSVoic

e



Voice Handover Mechanisms Contd


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IMS based Service Centralization andContinuity (SCC)

VoIP call on WLAN to circuit voice call onUTRAN/GERAN or CDMA 1x

Calls anchored on IMS SCC-AS Application layer mechanism

when access networks do not providesupport for voice handovers

Terminal makes handover decisions

VoIP

WiFi/WiMAX

2G/3GCore

MSC

IMS

CSVoic

e

CSVoic

e



LTE-Advanced


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Key feature of 3GPP Release 10, targeted for March 2011

Wider Bandwidth

Support for bandwidths larger than 20 MHz (40 MHz, 100 MHz)

Carrier Aggregation aggregate two or more component carriers Peak data rates of 1 Gbps DL, 500 Mbps UL

UL and DL Transmission Schemes

Beamforming, MIMO enhancements

Coordinated Multi-Point Tx and Rx (CoMP)

Improve coverage, cell edge throughput and/or system efficiency

Relaying

Relay Nodes forward traffic/signaling between eNB and terminals

Improve coverage of high data rates, extend coverage to shadowed areas etc.

LTE-Advanced submitted by 3GPP as candidate for ITU-R IMT-Advanced 4Gtechnology solution in October 2009



Summary and Conclusion


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y

LTE technology is being proven to meet or exceed initial target requirements

Large ecosystem of operators, vendors etc. committed to LTE

Commercial network deployments planned 2010 and beyond

EPC represents an efficient all-IP packet core Supports delivery of mobile Internet services with QoS over broadband radio

networks

Supports multiple access technologies (all 2G/3G cellular, WiMAX, WiFi etc.)

and mobility between these access networks LTE and EPC can cost effectively address the demands of future mobile

broadband growth



lte epc ieee comsoc rao april 8 2010

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