IEEE 802.11u Interworking & Vertical HandoverC7%D1%BF... · 2012-03-20 · 3G Core network and WLAN core network have each individual core network. Both core networks are connected

IEEE 802.11u Interworking & Vertical Handover

Youn-Hee [email protected]

School of Internet-MediaKorea University of Technology and Education

KRnet 20062

OutlineEvolution in Communication SystemsWLAN Interworking with Other Networks

WLAN vs. 3G

Goal of WLAN & 3G Integration

Architectural Issues for WLAN & 3G Integration

Scenario of WLAN & 3G Integration

WLAN/WMAN Handover Scenarios

IEEE 802.11u StandardizationIntroduction & History

Expected Technical Results

Research Trends & Conclusions

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Mobile Communication RoadmapMobility

HighSpeed

LowSpeed

4 G4 G

802.11b

CDMA2000, EV-DO/DV

W-CDMA(UMTS, FOMA), HSDPA

2.4 GHzWLAN

802.11a/g

CDMA/GSM/TDMA

WPANHigh speed

WLAN

MediumSpeed

WiBro802.16e

Wi-Max5 GHz WLAN

Bluetooth

RFIDZigBeeUWB

1995 2000 2005

<100 Mbps~ 14.4 kbps <10 Mbps384 kbps144 kbps

AMPSETACSJTACSNMT PAN

Data Rates

2010+

1G( Analog )

2G( Digital )

3G( IMT2000 )

3G+

<1 Mbps

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4G Mobile Communication Network

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Heterogeneous Network Operation

Fast, Reliable andFast, Reliable and QoSQoS GuaranteedGuaranteedSeamless Active HandoffSeamless Active Handoff

Always Best ConnectedAlways Best ConnectedUbiquitous NetworkUbiquitous Network

CDMA2000CDMA20001X/DO/DV1X/DO/DV

WCDMA/WCDMA/HSDPAHSDPA WLANWLAN WIBROWIBRO BluetoothBluetooth

UWBUWB

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Standardization Organization

QoS support during handover

UTRAN WLANCDMA2000

WiBro WLAN

IP based mobility support method

Network architecture

Access network selection algorithm

L2 Trigger for L3 handover

Power management for multiple interfaces

IEEE802.21/16g

IETF

3GPP 3GPP2

IEEE802.11u

연동network

이종망연동을위한요소기술

ITUNGN

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OutlineEvolution in Communication Systems

WLAN Interworking with Other NetworksWLAN vs. 3GGoal of WLAN & 3G IntegrationArchitectural Issues for WLAN & 3G IntegrationScenario of WLAN & 3G IntegrationWLAN/WMAN Handover Scenarios




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Goal of WLAN & 3G IntegrationWLAN

Low cost, high data rate, small coverageDesigned for low terminal velocity (non-contiguous spots)Office, Stations, Department store, Subway etc.

3G Cellular NetworkHigh cost, medium data rate, large coverageEven a fast moving vehicle can use on-line browser

Characteristics 3G 802.11b (WiFi) 802.11a (WiFi5)Typical end-user Bit-rate < 2 Mbps < 5 Mbps < 10 Mbps

Typical range of stationary user 3-5 Km (dense urban area) 50-60 m 10-20 m

Handover Yes Limited Limited

Security High Low – being improved

Low – being improved

Coverage Wide area -contiguous

Hot spots – non contiguous

Hot spots – non contiguous

Mobility High speedStationary,Nomadic

Stationary,Nomadic

Service Voice and data Primarily data(VoIP)

Primarily data(VoIP)

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이종망 연동의 동기

‘높은 이동성 + 낮은 전송속도 vs. 낮은 이동성 + 높은 전송속도’ 두 가지방향으로 기술 발전 (e.g. Mobile network vs. Nomadic network)단일 접속망 기술로는 다양한 환경 및 다양한 서비스 요구 (e.g. 이동성 정도, QoS 요구량, 전력 소모량 등)에 대해 효율적으로 지원이 불가능하다.최근 활성화 되고 있는 무선랜 망을 통한 3G 서비스의 확대 제공

향후 General heterogeneous network 사이의 연동을 위한 기반 제공

목적

사용자 및 service 요구사항과 상황에 맞는 최적화된 접속망을 사용.3G 사용자 정보 및 인증 방법을 이용한 무선랜 서비스 이용

3G 서비스 (e.g. VoIP, Multimedia Service)의 무선랜을 이용한 제공

이종 접속망 간의 이동성 (Handover) 지원

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[K. Salkintzis, et. Al., “Common radio resource management for WLAN-UMTS integration at radio access level,” Proceedings of the IST Mobile & Wireless Communications Summit 2005, Dresden, Germany, June 19-23, 2005]


Very Tight Coupling

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Tight Coupling

[K. Salkintzis, et. Al., “ WLAN-GPRS Integration for Next-Generation Mobile Data Networks,” IEEE Wireless communications, Vol. 9, Issue 5, pp. 112-124, Oct. 2002.]

Loose Coupling


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Tight Coupling Loose Coupling

Features WLAN access network and 3G access network share same core network

3G Core network and WLAN core network have each individual core network. Both core networks are

connected by gateway

Easy and Vertical Handover(Paging, Billing, etc.)

& Improved handover performance

Both access providers can save money by using the other's network without

changing their own network

3G Access Provider don't need to build another core network for WLAN.

Just build WLAN hot-spotsSuitable for all WLAN technologies

Technically difficult to mergetunneling based (or switching based) complex 3G Core network and packet-

routing based WLAN network

Gateway can be a bottle-neck to the whole system performances

Only feasible if a single operator runs both networks

User profile might be transferred by network for billing and roaming, which might be serious problem for security.

Disadvantage

Advantage


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[3GPP TR 22.934, Sep. 2003.]

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시나리오 13GPP 시스템 변경 요구 사항 전혀 없음

인증 및 보안 관련 기능은 두 시스템 별로 독립적으로 수행한다.

고객 입장에서는 WLAN 혹은 3G 중 어느 서비스를 사용하건 간에 단일화된

요금관리 및 고객관리 서비스를 받는다.

시나리오 23GPP 시스템에서 제공되는 Authentication, Authorization, Accounting 서비스를 WLAN에서 같이 사용하는 형태

3GPP 시스템의 재사용으로 WLAN 가입자는 자신의 USIM 카드를 사용한 인증으로

WLAN을 사용할 수 있게 됨

시스템 운영자나 가입자 모두 시스템의 큰 변화 없이 최소한의 노력으로

3G/WLAN 서비스를 연동

WLAN, 3GPP 각각에 대하여 세션 서비스를 동시에 독립적으로 지원

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시나리오 3운영자가 3GPP 시스템 PS (Packet Switching) 기반의 서비스를 WLAN 환경의

가입자에게 제공

IMS (IP Multimedia Subsystem) 기반 서비스, 위치기반 서비스, Instant messaging 등이 포함

3GPP 접속망과 WLAN 망과의 서비스 로밍은 지원

3GPP 접속망과 WLAN 망 사이의 서비스 연속성은 보장되지 않는다.이용 서비스에 대하여 사용자가 직접 단말기에 대한 재설정 필요

시나리오 4시나리오 3에서 제공되는 서비스가 WLAN과 3GPP 시스템 사이에 핸드오버를

하더라도 계속 유지되게 하는 것이다.이용 서비스에 대하여 사용자가 직접 단말기 재설정 필요 없음

적절한 레벨의 이동성 지원 기술 요구 (e.g. Mobile IPv4/v6)접속망의 변경을 사용자가 알 게 됨 (Seamless 성 보장 안됨) 세션 연속에 대한 서비스 품질 보장은 받지 못한다.

KRnet 200616


시나리오 5시나리오 4에서 제공되는 서비스에 대해 끊어짐이 없는 서비스 연속성을 제공하는

것이다. 끊어짐이 없는 서비스 연속성 (Seamless)은 접근 기술들이 바뀌는 동안에

데이터의 손실이나 정지 시간 등이 최소화되는 것을 의미

이때 사용자는 이런 중요한 변화를 알아차리지 못하게 된다.

시나리오 6WLAN 시스템에서 3GPP Circuit-switched service(예, 일반적 음성 전화)를이용할 수 있도록 함

WALN 시스템에 음성 전화의 Quality-level 또한 3GPP 에서 제공하는 것과

비슷해야 함

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Enforced Service ContinuityWhen one interface is (or will be) disabled, another connection is established to keep session continuityVHO Events initiated from lower layers: e.g. link down / link going downH/O Use Cases: 1 & 2

1

2

[Xiaoyu Liu and Youn-Hee Han, “Handover Scenarios and Use Cases between 802.16 and 802.11,” IEEE 802,21 Contribution,21-04-0098-00-0000-802.11_802.16_Handover_Scenarios.ppt, July. 2005.]

BS #1 BS #2

AP AP

AP AP

Operator’sBackbone Network

ASAServer

AP

APAP

AP

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BS #1 BS #2

AP AP

AP AP

Operator Backbone Network

ASA Server

AP AP

AP AP

AP


Policy Driven SelectionThe current interface is qualified while other interfaces are available, active session is switched from one interface to another driven by policies or smart decision makersA smart decision maker selects the optimal one based on user preferences and a set of policies.VHO Events initiated from upper layers or a policy engine module: e.g. link switchH/O Use Cases: 3 & 4

3

4

[Xiaoyu Liu and Youn-Hee Han, “Handover Scenarios and Use Cases between 802.16 and 802.11,” IEEE 802,21 Contribution,21-04-0098-00-0000-802.11_802.16_Handover_Scenarios.ppt, July. 2005.]

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WLAN Interworking with Other NetworksWLAN vs. 3G





IEEE 802.11u StandardizationIntroduction & HistoryExpected Technical Results


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IEEE 802.11u - Introduction

Study Group IEEE 802.11 WIEN (Wireless Interworking with External Networks)2004.05 ~ 2004.11About 20~30 ParticipantsGoal

Creation of PAR (Project Authorization Request) and 5Criteria with the objective of producing an output document

Working GroupIEEE 802.11u2005.01 ~ presentAbout 30~40 ParticipantsChair : Stephen McCann (Siemens)Goal (of PAR)

The goal of IEEE 802.11u is to produce an amendment to the IEEE 802.11 standard to allow a common approach to interwork IEEE 802.11 access networks to external networks in a generic and standardized manner.

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IEEE 802.11u - History

- Continue with supporting documents(scenarios and requirements)

- Down selection procedure discussions (Timeline)

- Technical presentations

- Liaison to external groups

- Define scope and requirements

- Requirements and Terminology Drafting

- Define set of external entities to liaise with. (e.g., IEEE 802.21, IETF Mipshop) - Continue drafting

supporting documents (scenarios and requirements)

- Review an IETF draft from the Internet Architecture Board : Architectural Implications of Link Indications

- Formal adoption of functional requirements: Motions on 18 requirements

- Liaison letter written to IRTF MOBOPTS (IP Mobility Research Group)

- Timeline Discussion

Jan. 2005 July 2005May 2005March 2005

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IEEE 802.11u - History

- 14 pre-proposal submissions covering most of the functional requirements

- Call for Proposal (deadline: 17th February 2006 23:59 ET)

Sept. 2005

- Formal adoption of functional requirements

- Liaison letters written to 11 external organizations(3GPP, 3GPP2, IETF, FMCA, Wi-Fi Alliance, IRAP, GSMA IEEE 802.1, IEEE 802.16, IEEE 802.21, WiMAX Forum)

Nov. 2005

- Update of the functional requirements document

- Formal adoption of two supporting document(Scenarios and Assumption, Down Selection Procedure)

- Pre-proposals Presentation (Huawei/Intel, Siemens, Panasonic, STMicroelectronics, FMCA, Root Inc, Nokia)

Jan. 2006 March 2006

- Proposal Presentations with 19 submissions

- Update of functional requirements document

- Update of Scenarios and Assumptions document

July 2006, Formal Proposals(Normative Texts)

May 2006

- Presentations of Merged & Updated 12 Proposals

Nov. 2006, Letter Ballot

Downselecting

Harmonization

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TBTT

NDB NDB NMB NMB NMB

NetworkDiscoveryIE

LegacyBeacon Signal(NMB)

NDBNDB NDB

high load (use active)Low load Low load

Thll

Thll


Multiple authenticationsSTA can be authenticated with multiple service provider networks through a single APExpected Solution: Virtual Link Concept (by Huawei)

Additional Info. Availability for Network SelectionSTA can discover whether the WLAN hotspot has a roaming agreement with their service providerExpected Solution (by Siemens, Nokia, LG…)

Passive: ESSID, Hashing, and Layered BeaconActive: New MAC Management Messages (Service Request/Response)

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Emergency Call Service via WLANDefine IEEE 802.11 functionality which would be required to support an Emergency Call (e.g. E911) service.Expected Solution: New Signal Flow (by Interdigital, Siemens, Nokia)

Ongoing association (optional)

STA AP

EmergencyServices needed

Beacon (Emergency_Capability_IE)Or probe resp (Emergency_Capability_IE)

Disassociate

(Re)association_request (Emergency_Service_IE) or (Re)association_request (SSID=EMERGENCY)

Open Authentication(Re)association response (AID)

Emergency VoIP Call Setup

Track/segregate traffic with MAC/AID

Step-1

Step-3

Step-2

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Expected Technical ResultsMAC Address Anonymity

It’s a standard feature of modern cellular networks that observers can not determine the real identity of a phone.The same level of protection should be extended to IEEE 802.11.Expected Solution (by Nokia, LG, British Telecommunications)

ESS MAC Identifier (EMID), Association MAC Identifier (AMID)

QoS MappingProvide mapping from external QoS information, e.g. DSCP, to IEEE 802.11 specific parametersExpected Solution (by Siemens, Panasonic, T-Mobile…)

New field, QoS Mapping Set, in Association ResponseTraffic Segregation

TRAFFIC-SEG Request/Response frame

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New Primitives for MIH (Media Independent Handover) Service

Input from IEEE 802.21Event

Link_Up, Link_Down, Link_Going_Down, Link_Going_Up…

CommandLink_Status_Polling, Link_Switch, Link_Power_Up/Link_Power_Down…

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IEEE 802.21 - Reference Model

MIH Reference Model for Mobile Stations with Multiple Protocol Stacks

MIH Key ServiceEvent ServiceCommand ServiceInformation Service

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MIH Function Key Service – Information Service

[PoA #1]Standards : 802 .11SSID: ---Channel : ---

[PoA #2]Standards : 802.16eService Provider : ---BSID: ---

[PoA #3]Standards : 802 .11SSID: ---Channel : ---

[PoA #4]Standards : GSMOperator Code _MNC: ---Cell_Identity_CID: ---

[PoA #5]Standards : GSMOperator Code _MNC: ---Cell_Identity_CID: ---

[PoA #6]Standards : 802 .16eService Provider : ---BSID: ---

[PoA #7]Standards : 802.11SSID: ---Channel : ---

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WLAN Interworking with Other NetworksWLAN vs. 3G








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Samsung’s View on B3G and 4G

High Mobility

Time

4G4G

2G2G3G3G

Mobile

Nomadic

Low Mobility

Revolution

Evolution

EvolutionWi-Fi

Wi-Max

W-PAN

GSM

IS-136

IS-95HSDPA

CDMA1x

WCDMA

GPRS

EV-DV

DMB

2005 2010+

IEEE802.16

IEEE802.11

Bluetooth UWB

B3G

IEEE802.16e

WiBro

2006 IT Forum Korea 발표내용 중

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Mobility Granularity

Horizontal Handover

Vertical Handover

Multiple Interface Management

Multiple Flow Management

A handover is initiated when mobile device exits the boundaries of an administrative domain. Single interface is used.

A mobile device does need to move in order to initiate a handover. Multiple interfaces are required, but use one interface at a time.

Simultaneous use of multiple interfaces and access networks. Association of an application with an interface

Ability to split individual flows between links with respect to the requirements of the flows and the user preferences

Com

plex

ity L

evel

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Mobility and Heterogeneity Problem Space

Mobility

Terminal Mobility Session Mobility Personal MobilityService Mobility Ad hoc Mobility Mode Mobility

Handover Management Location Management Contactablility Personalization

User Terminal Heterogeneity

Media Session HeterogeneityAccess Network Heterogeneity

Network Operator Heterogeneity Service Provider Heterogeneity

Terminal Interface Heterogeneity

Heterogeneity

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Key ChallengesScalability

Roaming from any access network to any other access network (2G, 3G, 4G, Wi-Fi, Wi-Max, Bluetooth, Satellite, Ethernet)

Cross-layer solutionsExtensions to layer 1 & layer 2 functionalities in order to optimize higher layer mobility architectures (MIPv4, MIPv6, SIP).

QOS guarantees during handoverNo disruption to user traffic

extreme low latency, signaling messages overhead and processing time, resources and routes setup delay, near-zero handover failures and packet loss rate

SecurityUser maintains the same level of security when roaming across different access networks.

Documents

IEEE 802.11u Interworking & Vertical HandoverC7%D1%BF... · 2012-03-20 · 3G Core network and WLAN core network have each individual core network. Both core networks are connected