다양한 액세스망 간의 연동기술
장영민
국민대학교 전자정보통신공학부
http://wireless.kookmin.ac.kr
02-910-4827
HSN2006
Wireless Networks & Communications Lab. -2-
Contents
▣연동 표준화 및 망구조
▣ IMS 기반 연동관련 기술
▣결론 및 추후 연구
연동 표준화 및 망구조
Wireless Networks & Communications Lab. -4-
The Vision on IMT
IMTIMT
IMT-2000IMT-2000 IMT-AdvancedIMT-Advanced
• IMT-2000• Enhancement of IMT-2000• Future development of IMT-2000
• IMT-2000• Enhancement of IMT-2000• Future development of IMT-2000
Systems beyondIMT-2000
Systems beyondIMT-2000
Wireless Networks & Communications Lab. -5-
The Vision on IMT (Cont.)▣Future developments of IMT-2000◈The terrestrial radio interfaces: up to 10Mbps and
further up to approximately 30Mbps (2005)
▣New capabilities of systems beyond IMT-2000 (2010)◈Up to approximately 100Mbps for mobile access
◈Up to 1Gbps for nomadic/local wireless access
Wireless Networks & Communications Lab. -6-
IMT-Advanced Network
Wireless Networks & Communications Lab. -7-
Technology Trends▣Relay, multi-hop mesh network
▣Mobile router
▣MIMO-OFDM, AMC, channel estimation, cooperative MIMO
▣ Interworking with other networks
▣Cognitive radio
▣Cross-layer and cross-network optimization
▣ IMS: Communication and Broadcasting Convergence
▣E2E QoS guaranteed IPv6 seamless vertical handover with multi-hop relay
Wireless Networks & Communications Lab. -8-
3GPP 표준화 동향▣3GPP◈TS 23.234 V6.3.0 3GPP system to Wireless Local Area
Network (WLAN) interworking; System description
◈TS 33.234 V6.3.0 Wireless Local Area Network (WLAN) interworking security
◈TS 24.234 V6.1.1 3GPP system to Wireless Local Area Network (WLAN) interworking; User Equipment (UE) to network protocols; Stage 3
◈TS 22.234 V7.0.0 Requirements on 3GPP system to Wireless Local Area Network (WLAN) interworking
◈3단계 연동관련 표준화 완료
◈4단계 시나리오의 표준화는 Rel. 7에서 진행 중
▣3GPP LTE◈Max. 100Mbps @ 20MHz(DL), 50Mbps@20MHz(UL)
Wireless Networks & Communications Lab. -9-
3GPP 단계별 시나리오1. Common Billing and customer care between WLAN and 3GPP
- Simplest form of integration, which provides only a common billing and customer care to the subscriber
2. 3GPP based access control and based charging
- A SIM card based authentication.
3. Access to Packet Domain based services from WLAN
- e.g. IP based multimedia services such as VoIP, Video Telephony
4. Session continuity between WLAN and 3GPP systems
- Services are continued without the need for user interaction.
5. Seamless services
- Follows Inter radio access network handoff requirements.
6. Access to 3G Circuit Switched services
Wireless Networks & Communications Lab. -10-
LTE Target Specification
Spectrum 3G spectrum(2GHz band and the additional bands)
Radio aspect WCDMA HSDPA, HSUPA Evolved UTRAN
RadioAccess DS-CDMA New elements
(OFDM, MIMO, etc)
UTRANRTT Several 100ms Several 10s to
100ms < 10ms
CarrierBandwidth 5MHz 1.25, 2.5, 5, 10,
20MHz
Data Rate 384Kbps ~ 2Mbps 14.4Mbps 50Mbps(uplink)100Mbps(downlink)
Mobility ~ 120 km/h(at least 384Kbps) ~ 120km/h ~ 350km/h
NW aspect Circuit Switch and Packet Switch Packet Switch only
Wireless Networks & Communications Lab. -11-
3GPP-Technical Trend1999 2003 2004 2005 2006
Rel-99
Rel-4
Rel-5
Stability Notice
Functional Freeze
Deep Freeze
Functional Freeze
Deep Freeze
Functional Freeze
IP Transport of CN ProtocolFlexible MSC C/U Separation
IMS(IP Multimedia Subsystem)HSDPA(하향 고속 패킷 서비스)Wideband AMRIMS 도입
Functional Freeze
R4
R5
E-DCH 서비스(상향 고속 패킷 서비스)
MBMS*All IPInterworking(IMS E2E 도입, 연동 시나리오 3까지)
R6Rel-6
Basic Functionality for WCDMAGlobal RoamingHigh Speed Data(2M)High Quality (AMR-CODEC)
R99
Rel-7 (Long Term Evolution)R7
2000 2001 2002
MBMS : Multimedia Broadcast/Multicast Service
Flexible Bandwidth(1.25 ~ 20MHz)RNC C/U SeparationOFDMTarget Data Rate : 100MbpsInterworking(E2E QoS, 연동 시나리오 4~6)
2007
2007년 6월
Wireless Networks & Communications Lab. -12-
3GPP Architecture
Wireless Networks & Communications Lab. -13-
3GPP LTE Architecture
Inter -connection
BS
BS
SN-C
SN-U SGW
AAA Registers
HA
BS : Base StationSN-C : Serving Node Control (plane)SN-U : Serving Node User (plane)SGW : Service Gateway
Include RNC
Wireless Networks & Communications Lab. -14-
3GPP Rel. 7 AIPN (All IP Network)
Wireless Networks & Communications Lab. -15-
Key Aspects of an AIPN▣ Seamless mobility across terminals and access systems▣ Common IP-based network
◈ IP-based network control◈ Interworking with IP & legacy networks
▣ Support of a variety of different access system▣ Advanced mobility management
◈ Mobility across access systems– Support fast/lossless/seamless handover
◈ Multiple dimensions of mobility– end-user mobility, terminal mobility, session mobility
▣ Access system selection◈ Evolve towards access system independence◈ Consideration
– Service requirements of an application– Load balance of the network– Charging & billing
▣ Enhanced Services◈ Ubiquitous services (RF tags, ..)◈ Group communication Services
▣ QoS◈ E2E QoS for an unicast and multicast traffic◈ Static business agreement need to be reconsidered
Wireless Networks & Communications Lab. -16-
3GPP2 Architecture▣3GPP2◈3GPP 보다 약간 늦게 표준화 작업 시작
◈S.R0087-0 Version 1.0, 3GPP2 – WLAN Interworking:
– Stage 1 Requirements
IS-95A/B
IS-95C
IS-95C
IS-95C
PSTN
Internet
AAAServer
HA
PDSN
MSC
BTS
BTS
BTS BSC
BSC
Radio Acces Network Core Network
HLR
IWF
Wireless Networks & Communications Lab. -17-
WiBro Architecture
Wireless Networks & Communications Lab. -18-
Interworking Architecture
▣Loose coupling + Tight coupling
Wireless Networks & Communications Lab. -19-
802.21 표준화 동향▣ IEEE 802.21 (Media Independent Handoff)◈ IEEE WNG SC에서 연동에 대한 논의가 시작됨◈04년 1월 회의에서 IEEE 802.21 WG 결성◈04년 5월 California 회의에서 논의된 사항
– Media Independent Triggers, Global Network Neighborhood
◈04년 11월: 13개의 Proposal 발표◈05년 7월:
– Media Independent Handover Reference Models 제시– Standards Compatibility 분석– MIH Convergence Function Specification 정의– Event Service Primitives 정의– Handover scenario 정의(수정 보완)
◈05년 11월:– IEEE 802.16g 규격에 맞춰 제안
◈06년 1월:– MIHF간의 통신에서의 프레임 헤더 논의– 3GPP, 3GPP2, IEEE 802.16, IEEE 802.11 상호 연동 정의
Wireless Networks & Communications Lab. -20-
802.21 표준화▣논리적 망 구조
Media Access
Multi-StackMS
AccessGateway
IntranetIntranet
CoN
802 AN (1)
3GPP RAN (1)
802.3
802.21 allows handovers acrossHeterogeneous
technologies
HA
Tunnel
IPV4
802.11
802.16802.15
SGSN
PDG(GGSN)
(FA)
WAG
3GPP CN (1)
InternetInternet
BTS/Node B
BSC/RNC
Access Router
LocalAAA
802 AN (X)
3GPP RAN (X)
3GPP CN (X)
HomeNetwork
HomeNetwork
HomeAAA
TunnelPLMNPLMN
Tunnel
AAAServer
Tunnel
Diamter /IPsec
Diameter/IPsec
Wireless Networks & Communications Lab. -21-
MIHF-MIHF Interfaces in Heterogeneous Networks
Terminal
MAC/PHY
MIHF
Upper Layers
AP
MAC/PHY
MIHF
APMAC/PHY
MIHF
Access Controller/ MIHF Server
MIHF
Access Controller/ MIHF Server
Base Station
MAC/PHY
MIHF
Upper Layers
Base Station
MAC/PHY
Upper Layers
Access Router
MAC/PHY
MIHF
Upper Layers
Wireless Networks & Communications Lab. -22-
Functional Elements of the MIH Information Service Architecture
Wireless Networks & Communications Lab. -23-
표준화 동향▣ IEEE 802.11u
◈ Interworking between WLAN and external networks
◈ Call for proposal: 2006년 3월까지 받음
▣ IETF
◈mipv4: Mobility for IPv4 WG
◈mipv6: Mobility for IPv6 WG
◈mobopts: IP mobility optimization RG
◈mipshop: MIPv6 Signaling and Handoff Optimization WG
◈monami6: Mobile Nodes and Multiple Interfaces in IPv6 WG
◈ dna: Detecting Network Attachment WG
◈ nemo: Network Mobility WG
◈mobike: IKEv2 Mobility and Multihoming WG
◈ capwap: Control and Provisioning of of Wireless Access Points WG
IMS 기반 연동관련 기술
Wireless Networks & Communications Lab. -25-
Why IMS?
Wireless Networks & Communications Lab. -26-
IMS 분석▣ IMS 특징◈ IP망에서 SIP 기반구조를 이용하여 멀티미디어 서비스 제공
◈Rel. 5에서 도입
◈Rel. 6에서 IETF SIP, IPv4와 연동 포함하여 기능 확장
▣ IMS 장점◈액세스가 독립적
◈다른 네트워크 망 구조를 사용하는 오퍼레이터와 서비스 제공자허락
◈SIP에 의해 사용자가 이동성을 제공받는 동안에 이동망은terminal 이동성을 제공
◈ IP에 근거한 어떠한 서비스라도 쉽게 제공
◈여러 단체에서 규격을 동일시하여 발전
Wireless Networks & Communications Lab. -27-
IMS 분석(Cont.)▣ IMS와 CS간의 연동 동향◈초기망에서 QoS보장이 안되어 VoIP 제공이 안되는 경우, 음성
전화와 같은 실시간 서비스를 위해 회선교환망(CS) 사용을 검토
◈TR 23.899(R6 V1.1.0 2005-02-25, Combining Circuit Switched (CS) bearers with IP Multimedia Subsystem (IMS)에서 가능한 방법들을 검토 및 제시.
◈TR에서 두 단계의 접근방법으로 분류하여 규격화 진행
– 1단계: CS 호 중에 IMS 세션을 열거나 IMS 세션 중에 CS 호를 여는 절차를 추가. CN에 제한적인 수정필요.
– 2단계: IMS에서 완전하게 CS 호를 제어. 규격에 변동 없음.
◈CS 콜은 실시간 bearer를 제공하기 위한 IMS 세션과 연관됨
◈ IMS 세션 setup의 부분인 네트워크기반의 CBCF(Circuit Bearer Control Function)의 제어로 이루어짐
Wireless Networks & Communications Lab. -28-
IMS Rel. 6–Work Items▣ IMS Rel. 6 주요 Work Items:◈ IMS Conferencing과 Messaging, 그룹관리
◈SIP 부가기능
◈ IMS SIP이 아닌 망(IETF SIP, IPv4)과의 연동
◈ IMS와 회선교환망과의 연동
▣그밖의 Work Items:◈ IPv4 기반의IMS와의 연동과 통합시나리오(주소변환, ALG 등)
◈QoS improvements (Gq)
◈3GPP의 PoC와 같은 서비스 제공방안
◈ IMS간의 공통성과 호환성
◈Flow기반의 과금 방안
◈Presence(TSG SA WG2)– 3GPP TS 23.141 V6.6.0 –Stage 2
– 3GPP TS 24.141 V6.2.0 –Stage 3
Wireless Networks & Communications Lab. -29-
IMS Rel. 7-Work Items▣패킷교환망과 IMS기반의 Emergency calls◈TR 23.867-Rel.6에서 시작되었으나 Rel.7로 넘겨짐
◈ IMS 관점과 PS 관점으로 나누어 진행
– IMS 관점에서는 TISPAN Rel.1 일정을 맞추기 위해 우선적 진행
▣End-to-end QoS◈ IMS기반에서 종단 QoS의 관리와 보장을 위한 다양한 시나리오
와 동작(TR 23.802)
◈TR에 서비스 선택 사항 기술
Wireless Networks & Communications Lab. -30-
IMS Features
Wireless Networks & Communications Lab. -31-
IMS 기반 연동망에서 QoS▣QoS management functions for UMTS bearer service
in the control plane
Transl. Transl.
RABManager
UMTS BSManager
UMTS BSManager
UMTS BS Manager
Subscr.Control
Adm./Cap.Control
MT GatewayCN EDGERAN
Ext.Serv iceControl
LocalServ iceControl
RA BSManager
Radio BSManager
RA NSManager
RANph. BS M
Radio BSManager
RAN ph. BS M
Local BS Manager
Adm./Cap. Control
Adm./Cap.Control
Adm./Cap.Control
RA BS Manager
RA NS Manager
CN BSManager
Ext. BSManager
CN BSManager
serv ice primitiv e interf ace
BB NSManager
BB NSManager
protocol interf ace
TE Ext.Netw.
Wireless Networks & Communications Lab. -32-
IMS 기반 연동망에서 QoS
RABManager
UMTS BS Manager
UMTS BSManager
UMTS BS Manager
Subsc r
. Control
Adm./Cap.Control Transl.
UE GatewayCN EDGEUTRAN
ExtServiceControl
Iu BSManager
RadioBS Manager
Iu NSManager
UTRAph. BS M
Radio BS Manager
UTRAph . BS M
Adm./Cap.Control
Adm./Cap.Control
Adm ./Cap.Control
Iu BSManager
Iu NSManager
CN BSManager
CN BS Manager
service primitive interface
BB NSManager
BB NS Manager
protocol interface
ExtNetw .
IP BSManager
Transl .
IP BS Manager
Policy DecisionFunction
ApplicationFunction
Go
Gq
▣QoS management function for UMTS bearer service in the control plane and QoS management functions for end to end IP QoS
Wireless Networks & Communications Lab. -33-
IMS 기반 연동망에서 QoS
▣SBLP(Service-Based Local Policy) entities
AF Session Signalling AF
(Application Function)
PDF (Policy Decision Function)
IP BS Manager
PEP (Policy Enforcement Point)
IP BS Manager
AF Client
Translation/mapping function Translation/mapping
function
UMTS BS Manager
UMTS BS Manager
Go
Signalling path
GGSN
UE
Gq
Wireless Networks & Communications Lab. -34-
QoS Architecture Overview
SGSNSGSNNodeNode--B/RNCB/RNC
UEUE GGSN (PEP)GGSN (PEP)
UEUE GGSNGGSN
▣ End-to-end QoS service
◈ Basic GPRS IP connectivity service - IP bearer resource based local policy decisions may be applied to the bearer
◈ Enhanced GPRS based service - SBLP (Service Based Local Policy) decisions are also applied to the bearer.
PDF (PDP)PDF (PDP) AFAF
Basic GPRS IP connectivity serviceBasic GPRS IP connectivity service
Enhanced GPRS based service (SBLP)Enhanced GPRS based service (SBLP)
PDP: Policy Decision PointPEP: Policy Enforcement Point
BackboneIP Network
Wireless Networks & Communications Lab. -35-
IMS 기반 연동망에서 QoS
GGSN
PSDN
ACR
Edge Router
Wireless Networks & Communications Lab. -36-
향상된 QoS 보장 방안
Wireless Networks & Communications Lab. -37-
향상된 QoS 보장 방안-3GPP
Wireless Networks & Communications Lab. -38-
향상된 QoS 보장 방안-3GPP▣Authorize QoS Resource, AF session establishment
(①~④)◈AF 세션을 성립하기 위한 QoS 자원을 인증
◈②번에서 서비스 종류에 따라 bandwidth 할당
– Bandwidth가 부족할 경우에 AF에게 재요청 후 PDF에서 Soft QoS적용
– QoS 등급별 서비스 제공방안
Users subscription information
Gold 1
Silver 0.8
Bronze 0.6
ξ
Wireless Networks & Communications Lab. -39-
QoS Class Mapping802.16e
Media-Type
(AF)QoS
Class
-VoIP with
silence
suppression
ERT-VR ertPS
Round-robin
(Periodic/dynamic assignment)
-Maximum latency
-Min. reserved traffic rate
-Max. sustained traffic rate
-Traffic priority
-Request/Transmission policy
-Unsolicited poling Interval
Hard
QoS
Soft
QoS
Application
Data
Delivery
Service
QoSScheduling
Services
Packet Scheduling
Discipline/Algorithm
QoSClass
(PDF)
UMTS QoSClass
(GGSN)
DiffServ
Class
Video (Voice)
Phone
-T1/E1
-VoIP without
silence
suppression
-Streaming
Video
-Video Phone
-FTP
(Download)
-HTTP
-Instant
Message
Round-robin
(Periodic/fixed assignment)
UGS
-Tolerated jitter
-SDU size
-Min. reserved traffic rate
-Max. latency
-Request/Transmission policy
-Unsolicited grant interval
UGS
rtPSRT-VR
NRT-VR
-Min. reserved traffic rate
-Max. sustained traffic rate
-Traffic priority
-Request/Transmission policy
BE
-Max. sustained traffic rate
-Traffic priority
-Request/Transmission policy
nrtPS
BE
Round-robin
(Dynamic assignment with delay constraint)
Max C/I
PF Scheduling
Class A
Conversation Class
VoD, AoD
Class B
Streaming Class
ControlClass
CInteractive –
Priority 1
Class D
Interactive –Priority 2
Class E
Interactive -Priority
Class F
Background Class
Best Effort
AF
Data
(HTTP
FTP
E-mail)
EF
★ EF : Expedited Forwarding
★ AF : Assured Forwarding
★ BE : Best Effort
★ UGS : Unsolicited Grant Service
★ (E)RT-VR : (Extended) Real Time-Variable Rate
★ NRT-VR : Non Real Time-Variable Rate
★ rtPS : Real-time Polling Service
★ nrtPS : Non- rtPS
★ ertPS : Extended - rtPA
Wireless Networks & Communications Lab. -40-
Network Selection▣ CASE #1: CDMA만 이용 가능한 네트워
크로 선택의 여지없이 CDMA 를 이용
▣ CASE #2_1: WLAN_O 영역에 있으며, 사무실에서 비디오나 오디오 같은 실시간트래픽을 사용
▣ CASE #2_2: CASE 2_1와 같은 지점에서data를 다운받는 등의 background 트래픽으로 전환 했을때, 이에 적합한 네트워크를 다시 선택
▣ CASE #3: 단말이 이동함에 따라WLAN_O의 신호가 점차 약해지며, 결국CDMA 망으로 핸드오버
▣ CASE #4_1: UMTS, WLAN_1, WiBro의네트워크가 존재하고 background 서비스를 이용할 때, 선택 알고리즘을 통하여 네트워크를 선택
▣ CASE #4_2: CASE 4_1와 같은 지점에서browsing과 같은 서비스를 이용하고자 할때, 서비스 클래스 변화에 따라 적절한 네트워크를 선택
InternetAccess router Access router
Access router
WLAN_0
WLAN_1
WiBro
RAS
AP
APBS
CDMA
Wireless Networks & Communications Lab. -41-
Network Selection(Cont.)
▣ 기존의 네트워크 선택은 수신파워만을 고려함
▣ 사용자의 요구를 반영한 다양한 QoS factors (RSS, throughput, timeless, reliability, security, cost)와서비스 클래스에 따른weighting을 줌
▣ 사용자 요구를 반영한 향상된품질의 서비스를 제공하는 최적의 네트워크를 선택
Wireless Networks & Communications Lab. -42-
이종망간의 정책 기반 무선자원 관리기술 연구▣ 정책 기반 기술
◈ 비즈니스 및 서비스 차원의 관리정책을 정의하고, 이를 기반으로 네트워크 및서비스를 일관된 정책에 따라 자동으로 관리하는 기술
▣ 정책 기반 관리 기술 컴포넌트
◈ PDP(Policy Decision Point)
◈ PEP(Policy Enforcement Point)
◈ LPDP(Local PDP)
Wireless Networks & Communications Lab. -43-
Cross-Layer Protocol Interactions
결론 및 추후 연구
Wireless Networks & Communications Lab. -45-
결론 및 추후 연구▣ Convergence
◈ Service + Network + Terminal◈ 통신 방송 융합 서비스
▣ 이종망간의 연동◈ WiBro + WLAN + CDMA + DMB◈ Satellite + Terrestrial Network (WLAN, CDMA)
▣ 이종망간 연동 전략 및 추세◈ 유선 Internet QoS + 무선 자원 관리의 통합 제어◈ Loose coupling -> Hybrid coupling -> Tight coupling ◈ MIPv6기반의 Fast and Seamless 핸드오버 방안 연구◈ 이종망 RRM으로의 접근
▣ QoS 보장형 연동 구조◈ Mobile IP 기반의 seamless mobility◈ Multi-hop relay 및 mesh network access tech.간의 공통 자원 관리 기술◈ Context-aware vertical handover◈ BcN 기반의 seamless하고 fast한 이동성 기술 연구◈ BcN 환경에서의 통합 인증기술 개발
▣ WiBro와 이종망간의 연동 상황 아래에서 VoIP traffic의 QoS 지원 방안▣ 이종망간의 연동 시에 backbone망의 QoS 제공 방안▣ 정책기반 end-to-end QoS 제공 방안