2003 Salih 3Gdata

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Overview of 3G Packet

Data

Salih Ergut

7/16/2003

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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

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Packet Data Architecture

BSC

MSC PSTNVLR

HLR

PCF PDSN

AAA

Packet

Network

Telephone

Network

Home

Agent

Home

AAA

SS7

Network

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Simple IP vs. Mobile IP

Mobile stations 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 PDSNPacket

Network

BSC

PCF

PDSN

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Mobile IP Registration

Mobile registersits care ofaddress

HA replies withlifetime

PDSN

(FA)

Packet

Network Home AgentBSS

MIP-RRQ

MIP-RRQ

MIP-RRP

MIP-RRP

Packet Data Tunnel (UDP over IP)

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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 ensuresthat 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

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Packet Network Nodes

AAA (Authentication, Authorization, andAccounting)

Stores accounting information andauthenticates/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

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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

UCSD Ericsson ///

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Control PlaneSignaling

BSC/PCF PDSN

A11

UDP

IP

Link

Phys

A11

UDP

IP

Link

Phys

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User PlaneRelay Mode

BSC/PCF PDSN

RS-23

2

RLPRS-23

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

Link

Phys

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User PlaneNetwork Mode

BSC/PCF PDSN

RS-23

2

RLPRS-23

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

Link

Phys

SLIP or

PPP

IP

PPP

IP

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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

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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

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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

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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

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Inter BSCIntra 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

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Quality of Service

Still standardization is continuing

Air interface is bottleneck for an end-to-end

QoS

Some parameters are defined such as

Users priority level (14 possible levels)

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

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

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1x EV-DV

(1xRTT Evolution for

high-speed integrated

Data and Voice)

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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

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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

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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

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Whats needed?

Radio resources should be optimally used

Radio link control & resource allocation must

be optimized

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How is it achieved? (1/3)

1x overhead

Residual power for 1x EV-DV

1xEV-DVoverhead

Power for 1x voice and data

BaseStationPower

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

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Fast sector switching

Fast channel quality indicator send by MS

Fast physical layer ARQ (Automatic Repeat

Request) which also provides error correction

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Whats 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.

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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 technologiesAll-IP vision: base stations become an access

router

Documents

2003 Salih 3Gdata