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1 Overview of 3G Packet Data Salih Ergut 7/16/2003
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Page 1: 2003 salih 3_gdata1

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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-speed integrated 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

HomeAgent

HomeAAA

SS7 Network

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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 PDSNPacket

Network

BSC

PCF

PDSN

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Mobile IP Registration

Mobile registers its care of address

HA replies with lifetime

PDSN(FA)

Packet Network Home AgentBSS

MIP-RRQ

MIP-RRQ

MIP-RRPMIP-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 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

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Packet Network Nodes

AAA (Authentication, Authorization, and Accounting) 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 the packets 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 Plane – Signaling

BSC/PCF PDSN

A11

UDP

IP

Link

Phys

A11

UDP

IP

Link

Phys

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User Plane – Relay Mode

BSC/PCF PDSN

RS

-232

RLPRS

-232

GRE

AIRInter-face

RLP

AIRInter-face

IP

Link

Phys

EndHost

IP

PPP

A10

IP

PPP

IP

Link

Phys

IP

Link

Phys

GRE

IP

Link

Phys

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User Plane – Network Mode

BSC/PCF PDSN

RS

-232

RLPRS

-232

GRE

AIRInter-face

RLP

AIRInter-face

IP

Link

Phys

EndHost

IP

SLIP orPPP

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 10-20

frames (~200ms) without tearing down traffic channel

Control/Hold Dormantsecond minute

ActiveFCH

ActiveSCH

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

Control/Hold Dormantsecond minute

ActiveFCH

ActiveSCH

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

Control/Hold Dormantsecond minute

ActiveFCH

ActiveSCH

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 BSC – Intra PDSN HHO

MSC PDSNSource

BSC/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

User’s 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 asymmetric nature 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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What’s 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-DV overhead

Power for 1x voice and data

Bas

e S

tatio

n P

ower

100%

Time

Packet Data Common Channel is introduced

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How is it achieved? (2/3)

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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How is it achieved? (3/3)

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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What’s next?

Reverse link data enhancements are necessary to meet the requirements, i.e. 1.25 Mbps

Common services and mobility with different type 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 to

increase 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