3G Data Tutorial

8/4/2019 3G Data Tutorial

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1

Overview of 3G Packet

Data

Salih Ergut

7/16/2003



2

Outline

cdma2000 packet data architecture and network elements Simple IP/Mobile IP

Packet Network Nodes State Machines MAC Layer Packet Data Call Flows

1x EV-DV (1xRTT Evolution for high-speedintegrated Data and Voice) Motivation, goals and basic principles



3

Packet Data Architecture

BSC

MSC PSTNVLR

HLR

PCF PDSN

AAA

Packet

Network

Packet

Network

Telephon

e Network

Telephon

e Network

Home

Agent

Home

AAA

SS7

Network

SS7

Network



4

Simple IP vs. Mobile IP

Mobile station’s IP address will be changed

as the subscriber moves to different cells

Mobile station will be able to use a constant

IP even when moving across different cells

BSC PCF PDSN Packet

Network

Packet

Network

BSC

PCF

PDSN



5

Mobile IP Registration

Mobile registersits care of address

HA replies withlifetime

PDSN

(FA)

Packet

Network

Packet

Network Home AgentBSS

MIP-RRQ

MIP-RRQ

MIP-RRP

MIP-RRP

Packet Data Tunnel (UDP over IP)



6

Packet Network Nodes

PCF (Packet Control Function) A required IP element in cdma2000 networks Provides relay to mobile from PDSN Keeps track of registration lifetime expiration and ensures

that the sessions are renewed as necessary

Controls the available radio resources Buffers data received from PDSN until radio resources

becomes available Controls dormancy

PDSN (Packet Data Serving Node)

PPP datalink layer to mobile is terminated Interfaces with PCF IP packets are routed In MIP network acts as a FA



7

Packet Network Nodes

AAA (Authentication, Authorization, andAccounting) Stores accounting information and

authenticates/authorizes mobiles Provides security to FA and Foreign AAA.

HA (Home Agent) Establishes a secure packet-data tunnel with

the FA to provide MIP services and routes thepackets destined to the mobile to the FA Authenticates MIP registrations



8

Assign Complete

Mobile Originated Packet Data Call

MSCPDSNBSC / PCF

Origination

Base Station AckCMServReq

SCCP-CC

Assign RequestTCH Setup

A11-RRQ

A11-RRP

User Packet Data

PPP Link Establishment and Mobile IP Registration

A8 /A10

setup

Packet

Network

Packet

Network

UCSD Ericsson ///



9

Control Plane – Signaling

BSC/PCF PDSN

A11

UDP

IP

Link

Phys

A11

UDP

IP

Link

Phys



10

User Plane – Relay Mode

BSC/PCF PDSN

R S -2 3

2

RLPR S -2 3

2

GRE

AIRInter-

face

RLP

AIRInter-

face

IP

Link

Phys

End

Host

IP

PPP

A10

IP

PPP

IP

Link

Phys

IP

Link

Phys

GRE

IP

LinkPhys



11

User Plane – Network Mode

BSC/PCF PDSN

R S -2 3

2

RLPR S -2 3

2

GRE

AIRInter-

face

RLP

AIRInter-

face

IP

Link

Phys

End

Host

IP

SLIP or

PPP

A10

IP

PPP

IP

Link

Phys

IP

Link

Phys

GRE

IP

LinkPhys

SLIP or

PPP

IP

PPP

IP



12

MAC States (1/3)

Active Mode and DTX Data traffic flows Reverse pilot is not gated

MS and BS can discontinue traffic for 10-20frames (~200ms) without tearing down trafficchannel

Control/Hold Dormant

second minute

Active

FCH

Active

SCH

millisecond



13

MAC States (2/3)

Control Hold Triggered when the data traffic is idle ~1-2 seconds Signaling only Power control is maintained Reverse pilot can be gated MS Stores radio information


second minute

Active

FCH

Active

SCH

millisecond



14

MAC States (3/3)

Dormancy Triggered when data traffic is idle ~1-2 minutes

Traffic channels and A8 (BSC-PCF) connection is

released A10 (PCF-PDSN) connection and PPP is maintained


second minute

Active

FCH

Active

SCH

millisecond



15

Dormant Mode

Initiation BSC initiates when inactivity timer is expired or RF failure

occurred

MS initiates when inactivity timer is expired or TCH is

released

Reactivation Initiated when network or MS has data to send

Since PPP is maintained no extra control plane signaling

required

User data is exchanged after reactivation



16

Inter BSC – Intra PDSN HHO

MSC PDSNSourceBSC/PCF

HO Required

HO Command

User Packet Data

HO Request

HO Request ACK

HO Commenced

TargetBSC/PCF

HO Direction Msg

Null Fwd Traffic

Rev Traffic

HCMTear Down Channels

Clear Command

Clear Complete

A11 RRQ (Lifetime = 0)

A11 RRP

A11 RRQ

A11 RRP

Handoff Complete

User Packet Data



17

Quality of Service

Still standardization is continuing

Air interface is bottleneck for an end-to-end

QoS

Some parameters are defined such as User’s priority level (14 possible levels)

Minimum acceptable data rate (2x, 4x, …)

Acceptable FER (1%, 2%, 5%, 10%)



18

1x EV-DV

(1xRTT Evolution for

high-speed integrated

Data and Voice)



19

Motivation

CDMA 1x supplemental channel scheduling is

slow (~2-4 secs) and data rate is not

satisfactory (~144 kbps)

Forward link has priority due to asymmetricnature of the data applications

Flexibility against short term and long term

voice and data demands



20

Design Goals

Backward compatibility with cdma2000 1x

cdma2000 1x features, applications and

services and voice/data capabilities are

maintained Minimal effect on the terminals and

infrastructure for cdma2000 1x customers

increase battery life as a side goal



21

Design Requirements

FL peak data rate > 2.4 Mbps

RL peak data rate > 1.25 Mbps

Average throughput in FL and RL > 600 kbps

Peak data rate and average throughput is at

least as much as 1X EV-DO



22

What’s needed?

Radio resources should be optimally used

Radio link control & resource allocation must

be optimized



23

How is it achieved? (1/3)

1x overhead

Residual power for 1x EV-DV

1xEV-DVoverhead

Power for 1x voice and data

B a s e S t a t i o n P o w e r

100%

Time

Packet Data Common Channel is introduced



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Left-over power is used, hence no power

control

Rate control (higher order modulation and

coding) is used to maintained link quality Optimally schedule delay tolerant data

Favor the user with good channel quality

Serve users both in parallel (CDM) and serial

(TDM) while TDM is preferred if possible



25


Fast sector switching

Fast channel quality indicator send by MS

Fast physical layer ARQ (Automatic Repeat

Request) which also provides error correction



26

What’s next?

Reverse link data enhancements are

necessary to meet the requirements, i.e. 1.25

Mbps

Common services and mobility with differenttype of network access technologies, such as

Wireless LANs, DSL, satellites etc.



27

4G

Higher data rates ~2-20 Mbps

New air interface needs to be developed Potential candidate OFDM

Smart antennas can form directed beams toincrease strength of the desired signal

A new spectrum needs to be assigned

Software radio can transmit over different air

interface technologies All-IP vision: base stations become an access

router

Documents

3G Data Tutorial