Seamless MobilitySeamless Mobility - mmlab.snu.ac.krmmlab.snu.ac.kr/links/hsn/workshop/hsn2002/documents/IX_2.pdf · 2G/3G/4G Seamless Mobility ... zSupports registration, authentication,

Seamless MobilitySeamless MobilitySeamless Mobility

KT연구개발본부멀티미디어연구소

박철희

[email protected]

2002. 2. 22

2

What is Seamless Mobility ?Positioning of Seamless MobilitySeamless Terminal Mobility

Macro-MobilityMicro-Mobility

Seamless Personal MobilityUSIM based Roaming3GPP IMS

Seamless Service Mobility3GPP VHE

IST BRAIN/MINDBRAIN/UMTS InternetworkingBRAIN Micro-Mobility

Summary

ContentsContents

3

What is Seamless Mobility ?What is Seamless Mobility ?

Framework that provides users seamless terminal, personal, and service mobility servicesSeamless terminal mobility

Allowing user’s terminals to move from one physical location to another while having the same set of services available Ability of the network to ensure the continuous and seamless connectivity of a mobile node(MN) during macro- and micro-mobilityA special case of personal mobility

Seamless personal mobilityAbility to redirect communication across heterogeneous user devices based on personal identificationAbility of the network to ensure that mobile users can reestablish communication after a move across different administrative network domains or geographical regionsRoaming, SIP-based Mobility

Seamless service mobilityThis provides access to services independent of the user’s endpointsAllowing user to see the same set of personalized services from all end-pointsVHE, Service Portability

4

Positioning of Seamless Mobility Positioning of Seamless Mobility

WLANHIPERLAN Fixed Wire

Media Gateways, Signaling Gateways Adaptation Layer

Routers, Switches

Seamless Terminal, Personal, Service Mobility

Application Servers

IP Transport Layer

Seamless Mobility Layer

Application and Service Layer

Short rangePAN/LAN/MAN

BroadcastDVB/DAB 2G/3G/4G

Seamless Mobility FrameworkSeamless Handoff, Path setup, Routing Mechanism for MNsSeamless Personal Connectivity, Roaming, Session Control MechanismService Adaptation, VHE

5

Motivation고객의다양한 Needs 및기술의급격한발달에따라 heterogeneous wireless/wired network들이각각의특성에따라혼재되어서비스되고있음또한, 궁극적으로모든유무선망은 All-IP 망으로통합되거나진화될것으로예측되고있고국제표준화기구들은그목적을달성하기위한연구및규격작업을진행하고있음

따라서유무선망통합및유무선복합서비스가 신규사업모델로부각되고있음

Seamless mobility framework은유무선망통합및유무선복합서비스개발의핵심기반을제공함

FocusQoS, security, and performance issues of seamless mobility framework are not discussedFunctional and protocol architecture of the framework is covered, especially focusing on packet based wireless data networks

Motivation and Focus Motivation and Focus

6

Micro-MobilityMovement management of a MN across different BSs within a domainFast handoff, Path setup, Paginge.g., 2G/3G link-level protocol, Cellular IP, HAWAII

Macro-MobilityMovement management of a MN across different domains within a single regionRouting based on globally routable address e.g., Mobile IP

표준화동향

IETF Seamoby WG : Context Transfer of all active IP flows, Handoff Candidate Discovery, Dormant Mode Host AlertingIETF Mobile IP WG : Mobile IPMicro-Mobility IRTF Routing Research Group

Seamless Terminal Mobility Seamless Terminal Mobility

7

Movement Detection : MN detects when it moves into a new location based on Router Advertisements that routers periodically broadcast

Address Auto-configuration : MN can derive COA(Care of Address) from Router Advertisements (Stateless Addr. Autoconfiguration) or be assigned a dynamic IP address from DHCP server (Stateful Addr. Autoconfiguration)

Location Updating : MN updates its location by sending Binding Updates to its HA(Home Agent) and other CN(Corresponding Node)s

Route Optimization : Any IPv6 node(CN) maintains its Binding Cache to store CCOA(Colocated COA)s of contacting MNs, which removes Triangle Routing

Macro Mobility Macro Mobility –– Mobile IPv6 Mobile IPv6

DHCP server

HA

Router Advertisements

CNBinding Updates

Binding Updates

Internet

MN moves

Home Network

Foreign Network A

Foreign Network B

8

Micro Mobility Micro Mobility

MotivationTo solve QoS and efficiency issues of Mobile IP in situations where MN changes its point of attachment to the network so frequently

CategoriesHierarchical tunnel approach : Regional Tunnel Management, BCMPRoute update approach : Cellular IP, HAWAII

Global Internet with Mobile IP

Wireless AccessNetwork Local Handoff

Macro-Mobility

Micro-Mobility

Gateway

Global Mobility

Domain Root Router

Coarse grain Mobility

Fine grain Mobility

9

Supports registration, authentication, paging, handoff (=cell reselection) as well as channel access procedure to transmit data packetsWhen MN moves between SGSNs or between RNCs on a SGSN, new GTP(Generic Tunneling Protocol) tunnels are established to manage mobilityData packets are encapsulated with an outer GTP/UDP/IP headerLink layer mobility mechanism is employed between node Bs on a RNC

UMTSBackboneNetwork

SGSN Internet

SGSN

GGSN

VLR HLR

MN

GTPGTP

PPP

Link Layer Mobility

RNCNode B

RNCNode B

Iu-PS

Micro Mobility Micro Mobility -- 3G UMTS 3G UMTS

10

PDSN : NAS(link – internet interface, AAA interface) + MIP FAR-P mobility : e.g., Mobile IP-based L2 tunneling between PCF and PDSN

Tunnel is set-up by Mobile IP registration request/reply message with IMSI exchanged between PCF and PDSNPPP traffic between PCF and PDSN is encapsulated with GRE(Generic Routing Encapsulation) header

VLR HLR

IPBackboneNetwork

PDSN(FA)

Internet

PDSN(FA)

HAMN

Mobile IP

BSC/PCFBTS

R-P IF

BSC/PCFBTS

PPP

Link Layer Mobility R-P Mobility

Micro Mobility Micro Mobility -- 3G CDMA2000 3G CDMA2000

11

Micro Mobility Micro Mobility -- Cellular IPCellular IP

구성요소 : Gateway + CIP nodes (=Base stations)Routing

Beacon PacketCIP GW periodically broadcasts this packet that is flooded in this access networkBased on this, each BS has routing information toward GWBased on beacon signal strength, MN detects where it is and when to handoff

Routing CacheEach BS has a RC which stores mapping (IP addr. of source MN, neighbor from which it receives packet), e.g. RC(BS2) mapping(X, BS3)This mapping is soft-state so that it remains valid for route-time-outAll data packets transmitted by MN, regardless of their destination address, are routed toward the gateway using the routing informationData packets from MN are used to maintain and refresh mappingsUsing this established routing cache, packets addressed to MN X are routed on a hop-by-hop basisTo keep its routing cache mappings valid, MN transmits route-update packet on the uplink at regular intervals called route-update time

12


HandoffHard handoff

When MN decides to handoff based on the signal strength measurement from neighboring BSs, it sends route-update packet to a new BSRoute-update packet creates new routing cache mappings that configure downlink route from GW to the new BSOnce route-update packet has created a new mapping at the crossover BS, no packets are transmitted along the the old pathAs a result, mappings between crossover BS and the old BS timeout and are removed

Semisoft handoffIn order to reduce handoff latency, routing cache mappings to the new BS must be created before the actual handoff takes placeBefore MN hands off to a new BS, it sends a semisoft packet to the new BS and immediately returns to listening to the old BSSemisoft packet is to establish new routing cache mappings between crossover BS and new BS After a semisoft delay, MN performs a regular handoff

13


PagingPaging Cache

BS may optionally maintain paging cacheAny packet sent by MNs can update paging cache, but paging-update packets cannot update routing cache

Passive connectivityMNs only need to report their position to the network if they moves between paging areas, which makes location updates and handoff support for idle MNs unnecessarySince paging cache mapping decays, MNs transmit paging-update packets at regular intervals defined by a paging-update-time

PagingOccurs when a packet is addressed to an idle MN, and GW and BSs find no valid routing cache mapping for the destinationIn CIP, the first data packet that arrives at the GW forms an implicit paging message which is forwarded in the access networkBSs that have paging cache will only forward a paging packet based on paging cache mapping. If BS has no paging cache, it will forward the packet to all of its interfaces except the one the packet came thru

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R Gateway CoA

BS1

BS2

BS4

BS3

MN X

HACN


Old BSNew BS

MN

Crossover BS

Route-update packet or semisoft packet

1. Beacon packet

2. Data packet or Route-

update packetHandoff

3. Data packet based on RC

mapping

RC(BS2) mapping (X, BS3)

BS with Paging cache

Paging area

Idle MN moves

Paging-update packet

15

Micro Mobility Micro Mobility -- HAWAIIHAWAII

R21

23 4

5 R31

23 4

5 R51

23 4

5


1BS0

2 1BS0

2 1BS0

2 1BS0

2

R11

23 4

5 R41

23 4

5

Domain root router 1


(1) 1.1.1.100-> wireless, 239.0.0.1

(2) 1.1.1.100-> port 3,

239.0.0.1

(3) 1.1.1.100-> port 4,

239.0.0.1

MN IP : 1.1.1.100 BS1 IP : 1.1.1.1MN

Mobile IP

HAWAII

2. Power-up msg

1. Mobile IP registration

msg

3. Power-up msg

4. Ack


reply

Path Setup

Forwarding Path Entry

16


R21

23 4

5 R31

23 4

5 R51

23 4

5


1BS0

2 1BS0

2 1BS0

2 1BS0

2

R11

23 4

5 R41

23 4

5



(2) 1.1.1.100-> Port 2,

239.0.0.1

(3) 1.1.1.100-> port 4,

239.0.0.1

(0) 1.1.1.100-> port 4,

239.0.0.1

MN IP : 1.1.1.100 BS1 IP : 1.1.1.1 MN

Mobile IP

HAWAII

2. Handoff msg


msg


reply

Micro-Mobility = Local HandoffForwarding path setup scheme

(4) 1.1.1.100-> wireless, 239.0.0.1

3. Handoff msg

4. Handoff msg

17


R21

23 4

5 R31

23 4

5 R51

23 4

5


1BS0

2 1BS0

2 1BS0

2 1BS0

2

R11

23 4

5 R41

23 4

5



(0,4) 1.1.1.100-> port 4,

239.0.0.1

(0) 1.1.1.100-> port 4,

239.0.0.1

MN IP : 1.1.1.100 BS1 IP : 1.1.1.1 MN

2. Broadcast Page msg


msg

1. Page request

Paging

(3) 1.1.1.100-> wireless, 239.0.0.1

Buffer data packet

4. Path setup msg

Mobile IP Data HAWAII

1

2

R3 - Multicast tree of paging

area, 239.0.0.1, (multicast group)

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R21

23 4

5 R31

23 4

5 R51

23 4

5


1BS0

2 1BS0

2 1BS0

2 1BS0

2

R11

23 4

5 R41

23 4

5


(HA)Domain root

router 2

(3) 2.2.2.200-> port 3,

239.0.0.2

(5) 1.1.1.100-> 2.2.2.200

MN IP : 1.1.1.100 BS1 IP : 1.1.1.1 CCoA : 2.2.2.200 MN


msg

Macro-Mobility = Inter-domain handoff

(1) 2.2.2.200-> wireless, 239.0.0.2

2. Power-up msg

Mobile IP

HAWAII

3. Power-up msg

4. Ack

(2) 2.2.2.200-> Port 4,

239.0.0.2


msg6. Mobile IP registration

reply


reply

19

Micro Mobility Micro Mobility -- CIP & HAWAII CIP & HAWAII 비교비교 분석분석

- Sub-optimal routing between domain root router and MN may occur since handoff message goes to the previous router

- CIP nodes must snoop each packet to extract the location information of MN

- All packet generated within CIP domain must be routed by GW, even if CN is located in the same domain

단점

- HAWAII router can be a legacy router with enhanced control software

- Simplicity

- Optimal downlink path between GW and MN since route-update & data packets from MN always go to GW

장점

- IP 기반의 Fast handoff

- HAWAII router is used

- Forwarding entry table

- Use special signaling message for paging, handoff and path setup

- IP 기반의 Fast handoff

- Simple operation of CIP nodes

- Soft state routing table : RC, PC

- Use data packets for paging and to update PC & RC

특징

HAWAIICellular IP

20

Ability of the network that allows users to access any type of contents with any type of terminal & network regardless of when they want and where they areUSIM based Roaming Mobile IP + AAASIP-based Personal Mobility : 3GPP IMS(IP Multimedia Subsystem)

Seamless Personal Mobility Seamless Personal Mobility

21

USIM based Roaming ArchitectureUSIM based Roaming Architecture

IP backbone

HLR

2G/3G OperatorCore Network

OperatorIP Core Network

AP

AP AP

AC

WLAN Access

AuthenticationServer

PDSN

RAN

BSCRAN

BSC

MSC/IWF

SS7

1.Get IP address from AC, and initiate network authentication request to AC

2.AC relays authentication request to Authentication Server, which implements gateway between WLAN access network and 2G/3G signaling network

3.Authentication Server queries HLR for authentication data and performs user authentication using this information

ChargingGateway

22

IP

802.11

UDPTCP

Mobile Terminal

Access Point

Access Controller

Authentication Server

Charging Gateway

IP

802.11 Ethernet

IP

Ethernet WANlink

TCPUDP

IP

WANlink Ethernet

TCP/UDP

IP

Ethernet

TCP/UDP

RoamingControl

USIM NAAP NAAPRADIUS

clientRADIUSServer

Accessmanager

AuthenticationController

Accounting

FTAM FTAM

IP-USIM authentication

signaling

RADIUS authentication

RADIUS accounting

CDR transmission

Signaling Link to HLR

USIM based Roaming ArchitectureUSIM based Roaming Architecture

23

3GPP IMS Architecture3GPP IMS Architecture

P-CSCF MGCF SG

Applications/Services

Appl.Application

Servers Appl.

I-CSCF S-CSCF

MRF

HSS

SGSN GGSN MGW

UTRAN

PSTN/ISDN

Router Router Internet

MAPSIP

SIPSIP

SIP to MN MGCP

ISUP

ISUP

OSA, SIP

Home Service Network

Home Session Control Network

Gateway Control Network

Visited Session Control Network

Macro-Mobility Network

24

Services

User Control

SessionControl

CN Mobility

RAN Mobility

Connectivity

RAN Mobility

Connectivity

CN Mobility

Connectivity

User Control

SessionControl

Services

User Visited RAN

Visited Core NW

Home Core NW

Home Service NW

3GPP IMS Architecture3GPP IMS Architecture

특징

SIP personal mobility management is performed in HE of the user after the user registers its location to home S-CSCF with the IP address that is allocated from the visited network

Users can access HE services even when they are roaming

Provides Home Domain Controlled VHE framework

25

Framework that provides the same look and feel to end users3GPP VHE(Virtual Home Environment)

Service Portability 환경Service Personalization 환경

PSE(Personal Service Environment)

Seamless Service Mobility Seamless Service Mobility

26

VHE ArchitectureVHE Architecture

Service Capability Servers

VHE Server (Visited)

Applications

OSA APIs

CAMEL

PDSN

MExE

MGW

USATHSS

Core Transport Network

CSCF

OSA Interface

PSE Information

3G 4G

WLAN xDSL

Access Network

2G PSTN

RouterxGSN IWF

Control Servers : Call/Session Control, Location Management, Adaptation, Security, QoS

VHE Server (Home)

Applications

PSE

User Profile

Contains 1:N

Services

User

Contains 1:N

HE

27

IST BRAIN/MINDIST BRAIN/MIND

BRAIN (Broadband Radio Access for IP based Networks )/MIND(Mobile IP based Network Development) : IST project 2000.1 – 2002.11

To create a framework that allows mobile users to access broadband multimedia services from wireless access technologies

To provide IP-based QoS support, mobility handling and adaptation mechanisms for broadband wireless access networks

Global Internet

IP backboneDiffServ

IP macro-mobility

BRAIN access networkIntServ

Micro-mobility (BCMP)

BAR

BAR BAR

BMG

Wired access networks(e.g. ADSL)

Vertical Handover

SGSNRNCNode B

UTRAN

GGSN

MN

DHCP AAA VHE SIP

BMG

28

BRAIN/UMTS InternetworkingBRAIN/UMTS Internetworking

No Coupling Approach환경 : Independent networks, Different Subscriber databases

SIP-based or MIP HA based Personal Mobility

Rapid introduction of mobility, but limited integration of applications and infrastructure of both

UMTS

MIP HA

SIP

Global Internet

BAR BAR

BMGSGSN

RNC

GGSN

BRAIN

MN moves

Global Internet

UMTS BRAIN

SIP home server CN

MN moves

(MIP-based Mobility) (SIP-based Mobility)

29


Loose Coupling Approach환경 : Independent networks, but Same AAA subscriber database

Authentication mechanism 연동기반의 Personal Mobility

One bill, but handover is not seamless

UMTS

Global Internet

BAR

BAR

BMG

SGSNRNC GGSN

BRAIN

AAAL

AAAB

AAAH

HLR

30


Tight Coupling Approach환경 : Integrated networks, and Same AAA subscriber database

BRAIN is a part of UMTS

Seamless Handover, but amount of modification to UMTS/BRAIN interface is much greater

UMTS

Global Internet

SGSN

RNC

GGSN

BAR BAR

BMG

BRAIN

MN moves

UMTS

Global Internet

SGSN

RNC

GGSN

BAR BAR

BMG

BRAIN

MN moves

IWU

31

BRAIN Micro Mobility BRAIN Micro Mobility -- BCMPBCMP

BRAIN Candidate Mobility Protocol구성 : BMG(BRAIN Mobility Gateway), ANP(Anchor Point), BAR(OAR, NAR, CAR)

특징

Multiple BMGs and ANPs in a BAN(BRAIN Access Network) : traffic load-balancing

ANP is a key component in BCMP, ANP-BAR tunneling, Planned/Unplanned Handoff

ANPs manage globally routable address space and allocate IP addr, to MN at login

BAN

BARBAR BAR

BMGBMG

ANP ANPANP

BAR BARBAR BAR

BMGBMG

ANP ANPANP

BAR BARBAR BAR

BMGBMG

ANP ANPANP

BAR

32


Initial Login : Address management and SecurityGlobal ID : NAI

Session ID : MN identifier in the following messages

Session key : used to authenticate the MN’s further messages

Login Req (global ID, security info)

BARBAR BAR

BMGBMG

ANP ANPANP

BAR

Login Req

AAAL

Login Rep

Login Rep(session ID, session key, IP addr)

33


Handoff and Path setupPlanned Intra-domain Handoff : Handoff preparation + Handoff execution

OAR NAR

BMG

ANPANP

3. HPReq-Ack

1. HPReq

2. HPReq

4. HPReq_Ack

5. Start tunneling packetsto NAR

1. MN based on its link-layer trigger sends to OAR Handoff preparation request (HPReq) which contains CAR(s)

2. From OAR, NAR receives HPReqwhich also contains the MN’s context information

2. When HOFF, OAR releases radio resources,

5. When HOFF_Ack, it releases all resources allocated to MN, including the temporary tunnel

OAR NAR

BMG

ANPANP

3. HOFF

1. HOFF

2. HOFF

4. New tunnel begins

5. HOFF_Ack

6. HOFF_Ack

5. HOFF_Ack

Data

Signaling

34


Handoff and Path setupUnplanned Intra-domain Handoff : Handoff execution

Context Information : AAA information, security context, QOS properties assigned to the MN, Robust Header Compression information

2. When HOFF, OAR releases radio resources and build a temporary tunnel to NAR,

6. When HOFF_Ack, it releases all resources allocated to MN, including the temporary tunnel

Data

Signaling

3. NAR extracts MN’s Context information from HOFF_Ack

OAR NAR

BMG

ANPANP4. HOFF

1. HOFF

2. HOFF

5. New tunnel begins

6. HOFF_Ack

7. HOFF_Ack

6. HOFF_Ack

3. HOFF_Ack

35


Inter Anchor HandoffSimilar to Initial Login process except no more AAA procedure

Data

Signaling

1. LReq

BARBAR BAR

BMGBMG

ANP ANPANP

NAR

2. LReq 3. LRep

4. LRep

2. Old ANP releases old IP addr, session ID

2. New ANP exhanges all necessary information with old ANP

3. New ANP allocates new IP addr, session ID and session key to MN

36


Paging

Data

Signaling

HOFF

BAR

BAR BAR

BMGBMG

ANP ANPANP

NARPaging Area

Idle MN

Paging

1. When ANP receives packets for idle MN, it forwards them to BAR at which MN went idle

3. Paged MN responds with HOFF messages to its closest BAR and performs unplanned handoff

2. IBAR pages and sends page messages to the other BARs in the paging area of the MN

37

SummarySummary

Mobile terminal technologyMulti-mode

Qualcomm : WLAN + 1X EV-DO 모뎀개발중Ericsson : HiperLAN2 + UMTS 모뎀개발중SDR(Software Defined Radio) 기술의성숙이요구됨

Unified execution platform다양한 VM 혼재3GPP MExE 규격

Seamless Micro-MobilityLow overhead, low power, scalable fast handoff schemeSeamless Context TransferIP RAN 구조

Global Service PersonalizationUbiquitous Connectivity

SIP, Mobile IP, AAAVHE

사용자정보 : PSE 표준화서비스구축환경 : OSA(Open Service Architecture) 표준화

Documents

Seamless MobilitySeamless Mobility - mmlab.snu.ac.krmmlab.snu.ac.kr/links/hsn/workshop/hsn2002/documents/IX_2.pdf · 2G/3G/4G Seamless Mobility ... zSupports registration, authentication,