1Qualcomm, Inc.

3G and WLAN Interworking forFixedFixed--Mobile ConvergenceMobile Convergence

Presentation for the CDG TechnologyForum on Inter-Technology NetworkingApril 30, 2008, San FranciscoPresenter: Rolf de Vegt, rolfv@qualcomm.com

2Qualcomm, Inc.

Agenda

1. Context and Introduction

2. Trends and Drivers for 3G/WLAN Interworking

3. Highlights of 3G-WLAN Inter-working Standards and System Architecture

4. Benefits of using 802.11n for WLAN Inter-working

5. Features and Enhancements for Improved 3G WLAN Inter-working

6. Technology Trial Results

7. Conclusions

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1. Context and Introduction

• The theme of the conference is Inter-Technology Networking

• The purpose of this presentation:

– Outline the trends and drivers leading to increased adoption of WLAN –Cellular Interworking

– Provide an overview of relevant standards and system architectures

– Highlight the benefits of using 802.11n technology

– Inform you about key enhancements QC identified for 3G – WLAN Interworking

– Share the results of a Field Trial of Qualcomm 3G – WLAN Interworking enhancements.

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2. Trends and Drivers for 3G/WLAN Interworking

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3G/WLAN Interworking for Converged IP Services

Operator Controlled 3G/WLAN Offering

3G3G WLANWLAN

OperatorOperatorServicesServices

OperatorOperatorClientClient

System Selection Transparent to the UserSystem Selection Transparent to the User

Seamless InterSeamless Inter--System Handoff System Handoff

Single Mobile NumberSingle Mobile Number

Benefits to Customers

Same Data and Voice Services Across Systems

Same Authentication/Authorization

Additional Revenue Opportunity

Improved WLAN AP Configurations

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End User Trends

• A third of wireless voice minutes are used either at home or at work

• Fixed-mobile substitution is a reality– Over 13 million landline phones replaced in

North America by 2007 (iGR, 03/07)

• Increasing adoption of VoIP– “Portable” phones and softphones can be

used anywhere with an IP connection

• Increasing usage of wireless data– Fast growth of 3G data services – Need for converged 3G/WLAN data services

Work10%

Home24%

Car40%

Other26%

Source: Yankee Group, 2005

Embedded WirelessNotebooks

US Wireless Voice Minutes Usage

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Drivers for Wireless Operators

• Coverage– In-building coverage extension– High data rates in poor 3G coverage areas

• Reduce Churn– Increase stickiness through custom plans – Enhance corporate plans (e.g. wireless PBX)

• Cost Reduction– Minimizes transport costs– Delay network investment to improve capacity

• New Services and Revenues– Bundled services– Accelerate wireline substitution– Rich services in poor 3G coverage areas

Wireless operators entering traditionally “fixed” domains

Residential flat rate“Homezone” plan

Per minute billingstandard plan

WLAN hotspotsextends

“Homezone”coverage

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Drivers for Wireline Operators

Wireline and MVNOs operators expanding services beyond the home

• Through partnerships, operators can offer mobile services• Reduce Churn

– Strengthen product portfolio and brand– Single bill for all services

• Cost Reduction– Reduce MoU on partner network– Use own transport network (DSL, Cable)

• New Services and Revenues– Become main communications provider– Recapture lost users and minutes to wireline substitution

Residential VoIP planprovides limited

mobility

Standard MNO provided mobility

services WLAN hotspotsextends

VoIP coverage

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Cellular/VoWLAN Dual-mode Handsets

A Growing Number of Cellular/VoWLAN dual-mode handsets available– DoCoMo launched Passage Duple service (WCDMA/VoWLAN) at end of 2004– Orange Unik launched in Oct 06– T-mobile HotSpot@Home launched in June 2007– Other service launches include BT, Telecom Italia, Telia Sonera, etc.

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3. Highlights of 3G-WLAN Standards and System Architecture

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Standards Support 3G/WLAN Interworking

MMD• Rev-0 and Rev-A published• Rev-B will be published Dec’07

VCC: X.P0042 (Stage-2 and 3)• HRPD VoIP 1X-CS• WiFi VoIP 1X-CS• Published by Oct ‘07

IMS• Rel-5 and Rel-6 published• Rel-7 frozen in Dec’06• Rel-8 expected to be frozen in 4Q’08

VCC: WiFi VoIP CS • TS 23.206 (Stage-2) and TS 24.206 (Stage-3) as part of Rel-7

UMA GAN• Access to A/Gb Intf (Rel 6/7) Published• Access to Iu Intf (Rel-8) In Progress

Approved:• 11a/b/g: power saving optimizations• 11e: QoS and talk time improvement• 11r: Inter-AP handoffs

In progress:• 11n: Increased throughput and range• 11u: WLAN / Cellular interworking • 11v: Further standby time improvement

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3G/WLAN Interworking for Packet Data Services

• Allows 3G subscribers to use WLAN to access an operator’s packet data services– E.g., rich multimedia to mobile phones and connectivity for laptops at hotspots

• Standardized in 3GPP (I-WLAN TS23.234) and 3GPP2 (X.S0028-200)– Authentication and security provided by PDIF and existing AAA– Multimedia Session Continuity (MMSC) to support seamless handoff being defined

in 3GPP (Rel-8) and 3GPP2

WLAN Access Network

PDG/PDIFPDG/PDIF

Internet

3G Packet Data Service (including Internet)

AAAAAA

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BSCBSC MSCMSC

Cellular Domain

Abis A

C

WLAN Access CSCFCSCF

VCC ASVCC AS

MGCFMGCF

MGWMGW

IMS Domain

IS-41

ISC

IS-41

AP

BTS

VLR

HLR/AC

HSS

PDIFPDIF

Internet

PSTN

3G-WLAN Voice Interworking Architecture (3GPP2)

WLAN AP:•Air link authentication•Optimized configurations

Dual mode handset:•Dual RF chains•IMS client software

MMD/IMS core network:•CSCF: SIP server•HSS for authentication•Media Gateway: MGW MGCF

VCC AS: – Manages mobile reachability info– Selects access for mobile terminated sessions

(UE selects access for mobile originated sessions)– Anchors all IMS sessions

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Voice Call Continuity: WLAN-3G Handoff

• Mobile decides to handoff from WLAN to 3G• Establish CS call and send signaling to VCC-AS• CS voice connection established to MGW• Tear down WLAN VoIP connection

BSCBSC MSCMSC

CSCFCSCF

VCC ASVCC AS

MGCFMGCF

MGWMGW

BTS

VLR

HLR/AC

HSS

PDIFPDIF

ISUP

SIP

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3G-WLAN Voice Interworking Architecture (3GPP)

RNCRNC MSCMSCIub Iu-cs

C

B

ISUP

ISUP

WLAN Access CSCFCSCF

VCC ASVCC AS

MGCFMGCF

MGWMGW

IMS Domain

MAP

ISC

SH

SH

MEGACO

SIP

MAP

AP

Node-B

VLR

HLR/AC

HSS

PDGPDGInternet

PSTN

VCC AS: – Manages mobile reachability info– Selects access for mobile terminated sessions

(UE selects access for mobile originated sessions)– Anchors all IMS sessions

PDG: provides VPN entry into carrier Intranet

Dual mode handset:•Dual RF chains•IMS client software

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4. Benefits of Using 802.11n for WLAN Interworking

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Introduction to 802.11n

• Latest generation of Wi-Fi Technology

• Wi-Fi Alliance started certifying interoperability of devices based on Draft 2.0 of the upcoming 802.11n standard in June 2006

• Certification of Approved 802.11n based devices scheduled to start in July 2009

Key Enhancements to Legacy Wi-Fi in 802.11n standard:

• Increased Throughput and Range due to the use of MIMO– WFA draft 2.0 testing, tests for 2 Spatial Streams, Standard specifies up to 4

spatial streams, with a max link rate of 600 Mbps

• Increased Throughput due to the use of Frame Aggregation Techniques and/or the use of 40MHz channels

Up to 5X the Throughput and 2X the Range compared to Legacy Gear

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Key Advantages of 802.11n

Enterprise and Hot SpotHome Environment

• Whole Home Coverage; a strong Wi-Fi signal that can blanket the entire home

• A whole family sharing an internet connection on a wide array of devices without degradation

• Moving HD video and audio streams effortlessly from device to devices, throughout the home

• Best user experience with voice calls, video games and other multimedia applications

• Back up large files in a snap

• Plenty of bandwidth to support data-intensive applications (e.g. video) and more users

• Reach hard-to-cover spots like stairwells, corridors, and exterior areas with ease

• Support more users on a more efficient WLAN infrastructure

• Ability for legacy 802.11a/b/g clients to connect

• Reduced CapEx and OpEx for Hot Spot providers, due to larger coverage areas of APs

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802.11n Access Points with Legacy Wi-Fi Radiosin Mobile Devices

11n AP – Legacy Client

• Most WLAN enabled Mobile Devices currently shipping with 802.11a, b or g

• Even without 802.11n Radios on the client side, notable Range and Power Consumption Benefits:

• Increased Receive Sensitivity at Access Points

• Transmit Diversity at Access Point

• Higher Data Rates Enabled at any given point

• Lower Output Power required of Client

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Benefits of Having 802.11n on Both Sides of the Link

• Range Extension for a Single Data Stream due to Support of SpaceTime Block Coding (STBC)

• Higher Throughput and Extended Range for Mobile Devices with Multiple Antennas (1x2 and 2x2 implementations)

• Higher Peak data-rates with Spatial Multiplexing:– 2 Spatial Streams: 130 Mbps– 1 Spatial Stream: 65 Mbps– Legacy a/g: 54 Mbps

• Higher Throughputs for transfer of large files (Music, Video, Pictures) due to Aggregation Techniques (A-MPDU orA-MSDU)

• Range Extension Due to the use of the Legacy Duplicate Mode

• Power Safe Features

• Increased Overall Network Capacity

• 11n will Spur Migration to the 5 GHz band– 5GHz is “cleaner” spectrum; fewer risks for interference– New 802.11n deployments can segregate voice on 5 GHz

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5. Features and Enhancements for Improved 3G – WLAN Interworking

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3G WLAN Interworking Considerations

• Robust Handoffs between Networks– Triggers and algorithms for efficient handoff– End-to-end call quality management

• Efficient Power Management– Improving WLAN standby and talk time

• Voice over WLAN Performance– QoS Management over WiFi – Interference in unlicensed spectrum

• System Search and Selection

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Mobile-Based Algorithms Enables Seamless Inter-system Handoff

• Robust and Efficient Handoff Algorithms achieve– Make-before-break handoff with no call drop– Maximize WLAN range while maintaining voice quality– Minimize packet losses during handoff– Stable handoff avoiding unnecessary ping-pong

• Handoff Algorithms Also Need to Handle Diverse Network Deployments and Usage Scenarios– 3G / WLAN handoffs with varying loading– WLAN to WLAN handoffs in enterprise settings

• Mobile-Centric Algorithm Can Meet all the Requirements Without Network Changes

3G NetworkWLAN

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Multiple, Intelligent Triggers for Robust Handoff Operation

• Signal Strength Based Handoff Alone Does Not Provide Adequate Performance – RSSI measurement is noisy near handoff boundary– Does not detect interference for WLAN connection – Cannot monitor uplink quality – Does not detect backhaul failures

• Improved Handoff Algorithm Combines PHY, MAC, and Application Layer Triggers for Greater Reliability1. Signal strength (RSSI)2. Uplink MAC frame failures and retransmissions3. Downlink VoIP frame losses4. Backhaul QoS degradation (PQMF)

Internet

VCC ASVCC AS

MGWMGWPDG/PDIFPQMF Server

PDG/PDIFPQMF Server

3G Network

MAC: Uplink Metrics

PHY: RSSI

APP: VoIP Frame Loss

APP: Path Quality Monitoring Function

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Reliability Improvement Through Application Layer Monitoring

• Path Quality Monitoring Function (PQMF) Measures Path Quality Between Device and Operator’s Network– Secure, adaptive, ping-type procedure with low overhead– Server function provided by PDG/PDIF

• With PQMF, Mobile Devices Can More Accurately Decide When to HO– Prevent initiate call on an overloaded WLAN system– Respond to WLAN QoS failures during call silence periods – Distinguish between local and remote link failures

Internet

Path Quality Monitoring Function

VCC ASVCC AS

MGWMGWPDG/PDIFPQMF Server

PDG/PDIFPQMF Server

3G Network

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Battery Life Close to 3G Phones

• Improved talk time by transitioning to sleep during calls– Based on power save mechanisms such as U-APSD

(802.11e)– Examples: talk time up to 6 hours in WiFi mode for T-

Mobile Hotspot@Home phones

• Improved standby time by intelligent WiFi scans and longer sleep periods– Example: a standby time of 4 days is claimed for T-

Mobile Hotspot@Home phones

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High Quality VoIP Calls in WLAN

• WLAN Can Meet Requirement of Voice Quality in Mixed Traffic– VoIP bandwidth is low compared to WLAN throughput– Explicit QoS provided for VoIP by 802.11e (WMM)

• VoIP Traffic Should Be Prioritized over the Backhaul Appropriately– May require agreements with ISPs– PQMF helps to detect backhaul QoS failures and

handing over to cellular if needed

• Adaptive De-Jitter Buffer Improves Voice Quality– Mitigate Effects of Variable Packet Delay

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Smart System Search and Selection

• Algorithms Optimized to Find and Select New Systems in a Fast and Efficient Manner– Minimize frequency of system scans and increase battery life– Identifying authorized, commonly used WLAN hotspots– Idle handoff between WLAN and WAN (and vice versa) – Finding systems quickly enough for mobility transition

• “Active Scan” algorithm can provide an order of magnitude performance improvement vs. basic scanning algorithm

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6. 3G/WLAN Interworking Technology Trial Results

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3G/WLAN Interworking Validated by Technology Trial

• Six weeks of real-world testing of handoffs between 3G and WLAN– Over 700 VCC calls with over VCC 1200 handoffs– Residential settings: suburban, urban, dense apartments– Enterprise settings with full coverage, spotty coverage

• Scenarios designed to test performance limits– Extensive walking test– Poor cellular coverage– WLAN and backhaul loading: downloads, uploads– Interference from microwave ovens, Bluetooth, cordless phones

• Extensive data collection and analysis used to fine-tune algorithms and parameter Settings

Carrier-grade VoWLAN with imperceptible handoffs between 3G and WLAN

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Field Trial Architecture

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6. Conclusion

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3G/WLAN Chipset Solutions Available

• Leveraging its expertise in 3G and WLAN technologies, Qualcomm provides a leading 3G/WLAN interworking solution

• Commercial chipsets and software for UMTS and CDMA– Fully tested MSM software for both 3G and WLAN – Fully integrated IMS VoIP client software

• IMS/MMD standards compliant• Supports IMS/CS handoff (VCC)

– IOT test with infrastructure vendors • Successful IOT test with Nortel IMS and VCC-AS• Successful IOT test with other vendors

– Joint development with Kineto for UMA-GAN solution

WLANMSM

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Conclusion

• Qualcomm is leveraging its expertise in 3G and 802.11 technologies to provide a leading 3G/WLAN Interworking solution

• 802.11n technology provides key advantages in range, throughput,power consumption and network capacity

• Efficient algorithms and triggers enable robust seamless handoffs

• QoS and interference mitigation offer high voice quality over WLAN

• Smart system search and selection to maximize battery life

• IMS-based 3G/WLAN interworking is a reality that operators can leverage to provide FMC and future services

• Qualcomm provides complete 3G/WLAN solutions for terminals– Chipsets and IMS client software– Extensive testing by technical trial and IOT