september 2005 prof. ephi zehavi school of engineering bar ilan university, ramat gan, israel

Novel Architecture for Seamless interoperability between WLAN/WIMAX and 3G networks

September 2005 September 2005

Prof. Ephi ZehaviProf. Ephi ZehaviSchool of Engineering School of Engineering

Bar Ilan University, Ramat Gan, IsraelBar Ilan University, Ramat Gan, Israel

and proprietary information

Appended Patent #: 20060045069CELLULAR NETWORK SERVICE OVER WLANAugust 31, 2004http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=16&f=G&l=50&co1=AND&d=PG01&s1=zehavi&s2=ephraim&OS=zehavi+AND+ephraim&RS=zehavi+AND+ephraim

Ephi Ephi Z.Z.

Novel Architecture for Seamless interoperability between WLAN and 3G networksNovel Architecture for Seamless interoperability between WLAN and 3G networksMotorola Israel - September 21-22, 2005Motorola Israel - September 21-22, 2005 22

Outline of TalkOutline of TalkThe Convergence’s ProblemThe Convergence’s Problem

Network’s Architecture Network’s Architecture Wi-FI NetworkWi-FI Network Cellular NetworkCellular Network

Convergence’s ApproachesConvergence’s Approaches Loosely Coupled ApproachLoosely Coupled Approach Tightly CoupledTightly Coupled Approach (UMA)Approach (UMA)

New Novel Approach-Dual Coupled ApproachNew Novel Approach-Dual Coupled Approach

Operating PrinciplesOperating PrinciplesArchitectureArchitectureAdvantageAdvantage

ComparisonComparison

Summary and ConclusionsSummary and Conclusions

Ephi Ephi Z.Z.




Convergence’s ApproachesConvergence’s Approaches Loosely Coupled ApproachLoosely Coupled Approach Tightly Coupled Approach (UMA)Tightly Coupled Approach (UMA)

New Approach-Dual Coupled ApproachNew Approach-Dual Coupled Approach



SummarySummary

Ephi Ephi Z.Z.


The market: WLAN and Cellular convergence. The voice over IP will set the wired and wireless worlds on a collision course, while at the same time providing opportunities for operators and vendors

Wireless Connection: More than 50% of the wireless connections are initiated or terminated at home or office

Dual Phone: Most of phones will use Wi-Fi based handset, either Single mode (Wi-Fi), Dual mode (3G, Wi-Fi) or Tri-mode (3G, CDMA, Wi-Fi) handsets

Objectives: How to allow a smooth interoperability between Wi-Fi/Wimax and cellular networks.How to reduce infrastructure’s cost

Observation and Observation and AssumptionsAssumptions

Ephi Ephi Z.Z.


Mobile operators may lose in-door revenue to Mobile operators may lose in-door revenue to Fixed-Line/Cable Operators when either significant low cost Fixed-Line/Cable Operators when either significant low cost VoIP calls are offered, orVoIP calls are offered, or whenwhen no in-door cellular signal is no in-door cellular signal is available, or when high mobile data rate is requiredavailable, or when high mobile data rate is required

The 3G network is expensive solution for out-door cellular The 3G network is expensive solution for out-door cellular coverage, while in-door 3G coverage cost times fourcoverage, while in-door 3G coverage cost times four

The 3G network cannot supply the capacity demand for in-The 3G network cannot supply the capacity demand for in-door data trafficdoor data traffic

The 3G suffers from restricted zoning rules, which induces constraints The 3G suffers from restricted zoning rules, which induces constraints deployment of new sitesdeployment of new sites

The 3G’s High Speed Packet Data Access (HSPDA) is limited to The 3G’s High Speed Packet Data Access (HSPDA) is limited to aggregate 10Mb/s per cell for all usersaggregate 10Mb/s per cell for all users

The Mobile Operators ProblemsThe Mobile Operators Problems

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SummarySummary

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IP BroadbandService Provider

MSC

How to allow interoperability?

PDSN

RNCRNC

MobileOperator

Public (Hotspots)SOHO / HomeEnterprise

MANAGED IPNETWORK

INTERNET

PSTN

PDN

The challenge is to provide seamless Mobility Management between Cellular and WLAN Networks for VoIP and Video services

???

Ephi Ephi Z.Z.




Convergence’s ApproachesConvergence’s Approaches Loosely Coupled ApproachLoosely Coupled Approach Tightly Coupled Approach (UMATightly Coupled Approach (UMA))




SummarySummary

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Loosely Coupled ApproachLoosely Coupled ApproachWLAN gateway supports Mobile IP Mobile-IP functionality to handle mobility across networks: AAA services to internetworking with the 3G’s home network

Separation of Data Paths in WLAN/3G Networks-Usage of WLAN gateway connects to the Internet and does not have direct links to 3G network elements such as PDSNs or 3G core network switches. The high speed WLAN data traffic is never injected into the 3G core network but the end user still experience seamless access.

Authentication and billing -Various mechanisms and protocols can handle authentication, billing and mobility management in the 3G and WLAN portions of the network – Billing and accounting - done by the 3G provide. A unified billing

statement

Ephi Ephi Z.Z.



MSCPDSN

RNCRNC

MobileOperator

Public (Hotspots)

SOHO / Home Enterprise

MANAGED IPNETWORK

INTERNET

PSTN

PDN


WLAN Gateway

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Observations-Loosely Coupled ApproachObservations-Loosely Coupled Approach

Easy and simply deploymentEasy and simply deployment

Handover of voice call- not supportedHandover of voice call- not supported

Subscribers prefer to connect voice and Subscribers prefer to connect voice and data services directly to the internet if it is data services directly to the internet if it is free and not through a cellular operatorfree and not through a cellular operator

Open Problem: How to utilize the WLAN Open Problem: How to utilize the WLAN network to increase the capacity without network to increase the capacity without loosing revenue? loosing revenue?

Ephi Ephi Z.Z.


Tightly Coupled ApproachTightly Coupled Approach

Concepts of UMAConcepts of UMAUMA Network Controller (UNC).- UNC appears to the core network as a GERAN base station subsystem– Security Gateway (SGW) that terminates secure remote access

tunnels from the Mobile Station– Mutual authentication, encryption and data integrity for signaling,

voice and data traffic.

A broadband IP network provides connectivity between the Access Points and the UNC. The IP transport connection extends

A single interface, the Up interface, is defined between the UNC and the Mobile Station

A UNC connects to a unique MSC and SGSN via the A-interface and Gb interface respectively. It maintains end-to-end communication with the MS and relays GERAN signaling to the A/Gb interface towards the Core Network.

Ephi Ephi Z.Z.


3G (UMTS) Network

WiFi AP

AP

IPAPMS

A

Gb

UMA

GSM

UMTS

Wi-Fi

Proprietary Clients

One phone with two interfaces in the same case

BSC/RNC

Tightly Coupled Approach (UMA) Mobile Operator

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Observations-UMAObservations-UMA

The UMA can not support soft handoff, The UMA can not support soft handoff, unless an interface between UNA and the unless an interface between UNA and the RNC is added RNC is added

The UMA solution has to be tailored for The UMA solution has to be tailored for every new core network standardevery new core network standard

Interfaces must be integrated in the dual Interfaces must be integrated in the dual handset MAC layer- Major change in handset MAC layer- Major change in

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SummarySummary

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The Dual Coupled Approach’s The Dual Coupled Approach’s ConceptsConcepts

Handoff in the Dual Mode handsetHandoff in the Dual Mode handset can be viewed as can be viewed as conference callconference call between the network and a phone with two between the network and a phone with two identities. identities.

The Access Point Communication Controller (APCC ) keeps the The Access Point Communication Controller (APCC ) keeps the two handset communication channels (Cellular and WLAN) opentwo handset communication channels (Cellular and WLAN) open simultaneously, while the data is transferred through simultaneously, while the data is transferred through one one channel at a timechannel at a time. .

Offering universal interface to CDMA, GSM and UMTS networks through tightly coupled approach (Intelligent switch connected to the core network, integrated with the IN

Capacity Gain- The non used channel is kept open for signaling Capacity Gain- The non used channel is kept open for signaling only, thus reduced the cellular spectrum usage by 87.5%only, thus reduced the cellular spectrum usage by 87.5%

The hand over is done at the application layer of the phoneThe hand over is done at the application layer of the phone

Ephi Ephi Z.Z.


Add on FeaturesAdd on Features Seamless mobilitySeamless mobility - allows subscribers to roam seamlessly - allows subscribers to roam seamlessly

between mobile networks and WLANs with a single handset for between mobile networks and WLANs with a single handset for voice and data services. APCC enables Parallel Access and Soft voice and data services. APCC enables Parallel Access and Soft Handoff between multiple networks such as Cellular, WLAN Handoff between multiple networks such as Cellular, WLAN (802.11a/b/g), Wi-Max networks(802.11a/b/g), Wi-Max networks

Low delay for handoffLow delay for handoff

QoS for VoIP and for video services QoS for VoIP and for video services is achieved in Dual is achieved in Dual mode handsets by leveraging the co-existence of mobile mode handsets by leveraging the co-existence of mobile networks and WLAN. networks and WLAN.

High Speed Internet AccessHigh Speed Internet Access (HSIA) enables Mobile Operators (HSIA) enables Mobile Operators to leverage broadband access and in-door WLANs to deliver to leverage broadband access and in-door WLANs to deliver high-performance mobile voice and data services at significantly high-performance mobile voice and data services at significantly lower cost to Wi-Fi based Mobile devices. lower cost to Wi-Fi based Mobile devices.

Single numberSingle number

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MSC

APCC

PDSN

RNCRNC

MobileOperator

Public (Hotspots)

The solution:Dual ModeCellular / WiFi Handset

SOHO / Home

Enterprise

MANAGED IPNETWORK

INTERNET

PSTN

PDN


Ephi Ephi Z.Z.


3G (UMTS) Network

WiFi AP

AP

IPAPMS

GSM

UMTS

Wi-Fi

The Dual Coupled ApproachStandard SIP/VoIPClient.Two phonesIn the same case

Dual Coupled Approach

VLR

APCCMedia

Gateway

SIP - Soft handoff between Cellular / WLAN is done in the APCC via ISUP interface- QoS

for GSM/ UMTSMobile Operator

Ephi Ephi Z.Z.


3G (UMTS) Network

WiFi

AP

AP

IPAPMS

Wi-Fi

The Dual Coupled Approach solution

Standard SIP/VoIPClient.Two phonesIn the same case

Dual Coupled Approach

APCCMedia

Gateway

SIP- Soft handoff between Cellular / WLAN is done in the APCCvia ISUP interface

MSC

PDSN

RNcdma2000

MS

VLR

HLR

RADIUS

A1

A10, A11

P-P

Soft handoff

ISUP

Radius

for CDMA2000Mobile Operator

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Basic ArchitectureBasic Architecture

Three major system components:Three major system components:Dual mode handsetDual mode handset

Uses standard VoIP/SIP channelUses standard VoIP/SIP channelAPCC-Access Point Communication Controller APCC-Access Point Communication Controller

Maintains secure tunnel with the mobile over IP transport Maintains secure tunnel with the mobile over IP transport IPIP

Handles mobility within IP networkHandles mobility within IP networkBridges between transport and cellular IP networkBridges between transport and cellular IP network

NMSNMSProvisioning and control of network of APCCs and the Provisioning and control of network of APCCs and the

APCCs connectivity to other network elementsAPCCs connectivity to other network elements

TransportIP Network

SGSN

MSC

PSTN

CellularCore Network

Mobile

APCC

NMS

PDN

GGSN

Internet

Ephi Ephi Z.Z.


Tightly coupledTightly coupled - Seamless integration of Wi-Fi Dual Mode handsets - Seamless integration of Wi-Fi Dual Mode handsets into the cellular network in a into the cellular network in a tightly coupledtightly coupled approach, using approach, using standardstandard interfaces and interfaces and standardstandard handsets with VoIP and SIP protocols handsets with VoIP and SIP protocols

One-NumberOne-Number - Single Cellular & Wi-Fi phone no. at work and at home - Single Cellular & Wi-Fi phone no. at work and at home

HandoffHandoff - Seamless and soft handoff between Cellular/WLAN and - Seamless and soft handoff between Cellular/WLAN and between APsbetween APs

QoS QoS – High QoS for VoIP calls and for Video services– High QoS for VoIP calls and for Video services

BroadcastBroadcast - Broadcast data streams from the cellular into the WLAN - Broadcast data streams from the cellular into the WLAN

Data PushData Push - Simultaneous Data Push and voice into the Dual handset - Simultaneous Data Push and voice into the Dual handset

““All IP” callsAll IP” calls – Loop back VoIP calls in WLAN for local users – Loop back VoIP calls in WLAN for local users

Presence function -Presence function - indicates the status of the called party indicates the status of the called party

CapacityCapacity - Increase cellular air-capacity by 400%. - Increase cellular air-capacity by 400%.

The APCC main featuresThe APCC main features

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Operational ConceptsOperational Concepts

““In some scenarios “ Mobile station device open In some scenarios “ Mobile station device open signaling connection to APCC through a Wi-Fisignaling connection to APCC through a Wi-Fi

Mobile device in idle mode keep signaling connection Mobile device in idle mode keep signaling connection with APCCwith APCC

Mobile initiates hand off-Mobile initiates hand off-– Subscriber start connection with the most reliable connection.Subscriber start connection with the most reliable connection.

Cellular connection routed to APCC using INCellular connection routed to APCC using IN

When Wi-FI connection reliable:When Wi-FI connection reliable:– Connection through cellular is at the lowest rate (1/4 -1/8 rate)Connection through cellular is at the lowest rate (1/4 -1/8 rate)

Ephi Ephi Z.Z.


State MachineState MachineMobile off

Mobile SearchCellular/

Wi_Fi

Wi_FiRegestration

CellularRegestion

Connectionto AP

Connectionto BTS

Slow Search of

cellularSearch

succes

FailureFailure

Slow Search of Wi

_FiSearch

succes

Idle Connection

to BothNetwork

SuccessSuccess

Failure Cellular connectionFailure of connection

to Wi_FI

Failure

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The Capacity GainThe Capacity Gain

AssumptionsAssumptions– X % of cellular connections are from indoor X % of cellular connections are from indoor

usersusers– K is the average power margin that is needed K is the average power margin that is needed

for indoor users (3-9 dB)for indoor users (3-9 dB)– C is the capacity of a cell shared between C is the capacity of a cell shared between

indoor users any out door users.indoor users any out door users.– In 3G technology the rate is partitioning In 3G technology the rate is partitioning

between multiple users, each one need a between multiple users, each one need a minimum SNR for a given rateminimum SNR for a given rate

Ephi Ephi Z.Z.


Capacity GainCapacity Gain

0%

100%

200%

300%

400%

500%

600%

700%

0.0% 20.0% 40.0% 60.0% 80.0% 100.0%

X- % of users indoor

Ca

pa

cit

y G

ain

R=1/2,K=2 R=1/4,K=4 R=1/6, K=8

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SummarySummary

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Comparison Comparison Dual Coupled Approach Operator Centric Solution Universal interface to CDMA, GSM and UMTS networks through switch connected to the core network, integrated with the IN

Performs Soft mobility Handoff between Cellular/ WLAN or Wimax at the network

Dual Mode handsets is viewed as two phones in the same case (Cellular & SIP/VoIP)

Tightly coupled Approach : Handset Centric Solution

Different H/W Interface for different networks (CDMA, UMTS)

Performs Handover between Cellular / WLAN in the handset, No soft handoff

Dual Mode handsets is viewed as one phone with two interfaces (cellular and WLAN)

Ephi Ephi Z.Z.








SummarySummary

Ephi Ephi Z.Z.


SummarySummary A third alternative to interoperability between WLAN A third alternative to interoperability between WLAN

and cellular networks was introducedand cellular networks was introduced The novel approach of dual coupled approach allows The novel approach of dual coupled approach allows

seamless soft handover between the networks using seamless soft handover between the networks using the IN features of the cellular/wireline networkthe IN features of the cellular/wireline network

The approach allows to be extended to other The approach allows to be extended to other emerging wireless standards like Wimax emerging wireless standards like Wimax

Thank youThank you

september 2005 prof. ephi zehavi school of engineering bar ilan university, ramat gan, israel

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