HSN2005 Portable Internet, WLAN, Cellular 망간의연동 장영민 국민대학교전자정보통신공학부 yjang@kookmin.ac.kr
Contents 통신방송인터넷융합망 국제표준화동향 휴대인터넷과무선 LAN/Cellular간연동 Seamless Vertical Handover 방안 결론 -2-
통신방송인터넷융합망
광대역통합서비스 4G Networks (System beyond IMT-2000) -4-
광대역통합서비스 (Cont.) 이용자중심의서비스이용환경요구 사업자의새로운수익원창출 기술진화방향 통신 ( 유 / 무선 ), 방송, 컴퓨팅서비스가융합 유 / 무선화상전화및 HD 급 VoD 연동서비스, 공중무선 LAN, 양방향데이타방송. 음성 / 데이터통합서비스 회선망 -> 패킷망 VoIP, 멀티미디어영상전화, 통합메시징, 다자간통화, MMoIP, MM 메신저서비스, 주문형영화 (VOD), 주문형음악 (MOD), 주문형게임 (GOD) 통신 / 방송융합서비스 맞춤형방송, 컨텐츠대화형방송, 시청자참여형방송 지상파 DMB, 위성 DMB 방송서비스, 개인방송, IP TV 사업 BcN 킬러애플리케이션개발 -5-
광대역통합서비스 (Cont.) Service 영역 Outdoor Indoor Vehicle Walk Stationary Walk Stationary/ Desktop 2G cellular Wide Area Network (WAN) -Large coverage -High cost 무선 LAN 과 3G 의서비스 gap 을해소하는경쟁 / 보완적서비스 3G cellular 2.3GHz 휴대인터넷 (HPi) IEEE802.11 IEEE802.15 LAN Local Area Network/Access - Hot Spots - High speed - Moderate cost Personal Area Network - Small area - Very low speed - Low cost IEEE802.15.3a (UWB) 0.1 1 10 100 1,000 Mbps -6-
국제표준화동향
연동표준화동향 ETSI BRAN HIPERLAN/2 와 3G 시스템간의연동을위한요구사항및구조정의 ETSI TR 101 957 V1.1.1 Aug. 2001 3GPP TS 23.234 V6.3.0 3GPP system to Wireless Local Area Network (WLAN) interworking; System description 을중심으로 3 단계표준화마무리작업중 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 2004 년 12 월 : 연동관련표준화 2005 년 3 월회의까지완료예정 4 단계시나리오의표준화는추후시작할것이며상당한시간이소요될것으로예상 -8-
연동표준화동향 (Cont.) 3GPP2 3GPP 보다약간늦게표준화작업시작 S.R0087-0 Version 1.0, 3GPP2 WLAN Interworking: Stage 1 Requirements IEEE 802.21 (Media Independent Handoff) IEEE WNG SC 에서연동에대한논의가시작됨 04 년 1 월회의에서 IEEE 802.21 WG 결성 04 년 5 월 California 회의에서논의된사항 Media Independent Triggers, Global Network Neighborhood 04 년 11 월 : 13 개의 Proposal 발표 05 년 1 월 : Layer 2.5 역할정의 Trigger 기능정의 Handover scenario 정의 ( 수정보완 ) -9-
연동표준화동향 (Cont.) IETF 2004. 11 Washington, 61th IETF Meeting mip6 : Mobility for IPv6 WG Binding update, Mobile IPv4/MIPv6 Interoperability 등 mobopts: IP mobility optimization RG Edge Handover L2 trigger for handover enhancement Fast handover for Hierarchical MIPv6 EAP: Extensible authentication protocol WG Network Discovery and Selection Problem -10-
3GPP 기반연동구조 3GPP 연동 Scenario Definition : 1. 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 (IMS) 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 -11-
3GPP 기반연동구조 (Cont.) 3GPP PS based services (Roaming reference model ) -12-
3GPP 기반연동구조 (Cont.) WLAN / 3G interworking architecture for scenario 3 (roaming case). -13-
802.21 MIH 기능 802.21 Handover 요구사항 서비스연속성 어플리케이션클래스 ATM이나 UMTS에서정의된클래스를따름 QoS 핸드오버프로세스에관여된각네트워크의 QoS 정보를획득하기위한수단을제공 네트워크발견 네트워크발견을위해상위계층에서서비스를제공 네트워크선택 핸드오버절차의시작전에네트워크의효율적인선택을하는서비스를제공 -14-
802.21 MIH 기능 (Cont.) 802.21 Handover 요구사항 (Cont.) 보안 개별적인액세스기술에따라보안요구사항을매핑할수있는수단을제공 파워관리 효율적인네트워크스캐닝절차를채택하여효과적인단말파워관리를제공 단말이동에따른핸드오버 무시할만큼의 QoS 저하 -15-
802.21 MIH 기능 (Cont.) MIH 참조모델 -16-
802.21 MIH 기능 (Cont.) MIH 참조모델 (Cont.) User Plane 와 Management Plane 로구분 MIH HLCF MIH 상위계층컨버전스기능을말하며, MIH 핸드오버와이동성관리의인터페이스를제공 MIH HO MIH 핸드오버기능을하며, 링크 Quality, 서비스, 가입자등의기준에따른핸드오버를결정 MIH LLCF 하위계층의컨버전스기능을하며, Physical 계층과 MAC 계층의이벤트를수집 -17-
802.X and 3GPP 연동 802.21 Logical 망구조 802.21 allows handovers across Heterogeneous technologies Multi-Stack MS Tunnel 802.3 802.11 802.15 802.16 Media Access Tunnel Local AAA Intranet Intranet Access Router Access Gateway Diameter/IPsec IPV4 PLMN PLMN Internet Internet Tunnel Diamter/IPsec AAA Server HA Home Home Network Network Home AAA CoN 802 AN (1) 802 AN (X) WAG Tunnel PDG (GGSN) (FA) BTS/ Node B BSC/ RNC 3GPP RAN (1) 3GPP RAN (X) SGSN 3GPP CN (1) 3GPP CN (X) -18-
802.X and 3GPP 연동 (Cont.) System Access, 802.X and 3GPP 802.X/3GPP MS 802.X MA/AG 3GPP CN 3GPP IP/MIP MIHHO MAC/PHY/ AAA MAC/PHY/AAA MIHHO DHCP/DNS WAG PDG 3GPP AAA INITIALIZATION At any point in time, MIH might report events to register listeners. Listeners register to the information serv ice and not to specific events Upon power up, 802.X MS ex ecutes scanning At any point in time, MIH might update the content of the system info carried within the beacon frame NTW_DISC_STATE 1 BEACON MIH_MACCONFIG MIH_MACINFO 2 MIH retriev es system info and triggers 3GPP authentication and association procedures. System info can be retriev ed from beacon or by query a data base when a 802.21 flag is detected within the beacon frame MIH_MACORDER EAPOL 3 Based on the NAI, the AG triggers EAP-AKA authentication and relay messages to 3GPP AAA. The AG might route AAA messages to other servers to prov ide, e.g., basic services EAP-AKA IPSec Tunnel 4 Obtain local IP address (v ia ARP or DHCP) EAPOL Get local IP address EAPOL<->EAP- AKA Cellular Authentication and Authorization 6-19-
802.X and 3GPP 연동 (Cont.) System Access, 802.X and 3GPP (Cont.) 802.X/3GPP MS 802.X MA/AG 3GPP CN 3GPP MIHHO MIP/IP MIP/IP DHCP/DNS WAG PDG 7 8 MS derives FQDN from W- APN Network Id and Operator Id Get PDG address based on FQDN [W-APN, PLMN Id] 802.x MS -PDG Tunnel (Internet Key Exchange (IKEv 2) Protocol ) 9 DNS returns PDG IP (I.e., tunnel end-point) MS-PDG/WAG 802 AG-PDG/WAG WAG-PDG WAG-PDG Tunnels can be established betw een MS-PDG (directly), AG- WAG-PDG or MS- WAG-PDG STEADY STATE 10 11 Compute CoA At any point in time, MIH might report events to register listeners. Listeners register to the information serv ice and not to specific events Agent Solicitation/Agent Advertisement 12 Register CoA Registration Request/Registration Reply HA 13 User data can be routed from HA to MS via PDG MS-PDG Tunnel FA-HA HA -20-
802.X and 3GPP 연동 (Cont.) Handover from 802.X to 3GPP 802.X/3GPP MS 802.X MA/AG 3GPP RAN/CN 3GPP MIP MIHHO MAC/PHY MAC/PHY MIHHO 1 2 3 STEADY STATE User data flow in progress between MS and correspondent node over 802.x via 3GPP PDG. Note that PDP Contex t is active at the GGSN MIH_PHY_EVENT MIH Processes and filters events and Measurements MIH_MAC_EVENT CoN 4 5 MIH_HO_PREPAR E Handov er Ev aluation 6 7 HO PREPARE STATE MS selects 3GPP cell and it updates routing area 3GPP LL/HL Preparation (E.g, Routing Area Update) 8 New SGSN requests Contex t transfer from PDG -21-
802.X and 3GPP 연동 (Cont.) Handover from 802.X to 3GPP (Cont.) MS PDG 802.X AG New RAN New SGSN GGSN (TTG) CoN APPL 3GPP 802.X MIHHO Tunnel is established betw een 802.x MS and PDg (E.g., L2TP) 9 HC HC Packet Data Protocol Contex t (E.g., Header Compression) GTP Tunnel ov er Gn interface PDP CONTEXT IS TRANSFERRED TOWARDS new RNC HC HC UL data stream is sw itched towards 3GPP side Access Network indepen dent HC PDP contex t is transferred from PDG to Target RNC trhough new SGSN 802.x -AG and PD Tunnel (E.g., L2TP) PDG buffers DL packets and forw ards copy through new GTP tunnel GTP Tunnel 10 HC HC RNC uses transferred contex t to handle packet stream New GTP Tunnel New GTP Tunnel HANDOVER IS COMPLETE 11 HC HC GTP Tunnel GTP Tunnel -22-
802.X and 3GPP 연동 (Cont.) Handover from 802.X to 3GPP (Cont.) 802.X/3GPP MS 802.X MA/AG 3GPP RAN/CN 3GPP MIP MIHHO MAC/PHY MAC/PHY MIHHO 12 MIH_HO_COMPLETE 3GPP LL and HL Connections established User data flow in progress between MS and correspondent node over 3GPP nework CoN MIH_MACORDER (Release) 13 Tear down old media (e.g., disassociate from 802.x netw ork) -23-
휴대인터넷과 WLAN/Cellular 간의 연동
연동요구사항 연동을위한서비스요구사항 Network Selection( 수신파워, 선호도등고려 ) 연결성 (Mobile IPv6) Access Control, 인증, 가입 Data 무결성과비밀성보장 (AKA 인증, USIM 기반 ) Accounting 공통고지서와고객관리 로밍 세션의연속성 -25-
휴대인터넷서비스 (Cont.) HPi Architecture AAA Public IP Network Service provider s IP Network HA Interface Reference Point U h : AP-AT A h : AP-PAR P h : PAR-PAR I h : PAR-INTERNET FA W-LAN AP PAR A h I h P h Mobile IP I h PAR A h NMS(O&M) Seamless handoff Inter AP Handoff Inter PAR Handoff HPi-AP HPi-AP W-LAN U h U h HPi-AT HPi-AT HPi-AT PAR : Packet Access Router NMS: Network Management System -26-
HPi 서비스사업방안 타망간의연동을통한상호보완적인서비스제공 여러서비스의장점을보완할수있음 높은 data rate + 넓은 coverage -27-
HPi 무선 LAN 연동 연동구조 ( 같은사업자경우 ) -28-
HPi 무선 LAN 연동 (MIPv6) (HPi -> WLAN 예 ) -29-
HPi - cdma2000 연동 연동구조 ( 다른사업자경우 ) -30-
HPi - cdma2000 연동 (MIPv6) (cdma2000 ->HPi 예 ) BSC PDSN RADIUS HA CH setup R-P setup MIP solicitation & advertizement PPP 인증수행 Registration request Registration response Registration request Registration response User Data AP PAR Diameter Probe setup Association EAP-TLS Access-Request & response TLS MIP solicitation & advertizement COA Binding update Binding update acknowledgement User Data -31-
Seamless Vertical Handoff 방안
HMIPv6 기반의연동망구조 Mobile IPv6 절차 -33-
HMIPv6 기반의연동망구조 (Cont.) Mobile IPv6 Mobile IPv4의주소공간, 보안, 라우팅의효율성개선 바인딩업데이트에따른문제발생 잦은이동으로인한추가적인핸드오프지연 연결이중단되는결과초래 HMIPv6 (Hierarchical Mobile IPv6) 제안 Lack of hierarchy in the MIPv6 단말이도메인내에서지역적인등록수행 Introducing the new protocol agent called MAP (Mobility Anchor Point) Inefficient use of resources in the case of local mobility MAP splits the management of the handoff process into micro mobility and macro mobility and deals with them separately 이동성이많이요구되는미래의 IP 기술로적당하다고판단됨 -34-
HMIPv6 기반의연동망구조 (Cont.) HMIPv6 기반의연동구조 그림 4.12 HMIPv6 기반의 CDMA/HPi 연동구조 -35-
HMIPv6 기반의연동망구조 (Cont.) 수직적인핸드오버호흐름도 (HPi cdma2000) -36-
호수락제어 제안하는 MAP 의 Soft QoS 기반의호수락제어 C + C < C occupied req total ξ C total C req C occupied : Critical bandwidth ratio : Total capacity : Required capacity : Currently occupied capacity C req ξ < Ctotal Coccupied ( 1 ξ) -37-
호수락제어 (Cont.) Soft QoS 개념 Critical bandwidth ratio ( ξ ) 최소한의만족허용도 자원의효율적인분배를위함 ξ = 0.6 : 60% 정도 performance를낮추어도트래픽의 QoS에큰영향을미치지않음 -38-
호수락제어 (Cont.) M / M / N + α / N +α 큐잉모델 λ H + λ V λ H + λ V H λv λ + λv λ V N N + 1 N + α µ 2 µ N µ ( N +1)µ ( N +α) µ λ H : Arrival rate of Horizontal handoff call or new call λ V : Arrival rate of Vertical handoff call µ : Service rate N α : Maximum number of connections : reserved capacity for vertical handoff call by ξ α = ( 1 ξ )N -39-
-40- 호수락제어 (Cont.), the steady state probability that the number of calls Is k in the MAP where, P k + + + = α µ λ µ λ λ µ λ λ N k N P k N k P k P N k V N V H k V H k,! 1 1 0,! 1 0 0 1 1 0 0! 1 ) ( ) (! 1 + = = + + + = k k P N N k k N k V N V H N k k V H α µ λ λ λ µ λ λ
호수락제어 (Cont.) 시뮬레이션결과 λ = 0.5, λ V = 0.1 ~ 100, µ = 0.2 H 0.1 Call blocking probability 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 Hard QoS Soft QoS (ξ = 0.8) Soft QoS (ξ = 0.6) Soft QoS (ξ = 0.4) 0.01 0 0 5 10 15 20 25 Call arrival rate [calls/sec] -41-
호수락제어 (Cont.) Transient Outage Probability Based on Fluid flow Model 트래픽모델 : On-Off 소스 State transition rate diagram ( H V N + α )( λ + λ ) N + α 1)( λ + λ ) α 1)( λ H + λ ) ( H V ( + V αλv ( α 1)λ λv V µ 2µ N µ ( N +1)µ ( N + 2)µ ( N + α) µ -42-
호수락제어 (Cont.) 시간에따른 Outage 확률 λ H =0.4, λ V =0.1, µ =0.833 10 0 10-5 Outage Probability 10-10 10-15 10-20 Soft QoS (Y(0)=0) Soft QoS (Y(0)=2) Soft QoS (Y(0)=4) Hard QoS (Y(0)=0) Hard QoS (Y(0)=2) Hard QoS (Y(0)=4) 10-25 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Prediction Time, t [sec] -43-
호수락제어 (Cont.) 호도착율에따른최대 Connection 수 λ =0.4, µ 3 =0.833, and =10 H QoS out Maximum number of connections 80 70 60 50 40 30 t=1, Soft QoS t=1, Hard QoS t=5, Soft QoS t=5, Hard QoS 20 10 0.05 0.1 0.15 0.2 0.25 0.3 Arrival rate of vertical handover call [calls/sec] -44-
HPi/CDMA 연동을위한단말기구조 통합단말기요구사항및특징 Dual mode 단말기 상황정보를이용한지능적이고효율적인핸드오버 각각의안테나및 RF 장치구현 SDR 기반 Independent MAC Combined MAC 망접속및선택관리등을위해소프트웨어적으로기능지원 수동, 자동, 망우선모드등 빠른핸드오프를위한채널예측모듈구현 L2 Trigger 사용 각 Layer (PHY, MAC 등 ) 로부터정보수집 Context-aware user interface 및모듈개발필요 -45-
HPi/CDMA 연동을위한단말기구조 (Cont.) Network Selection 문제 Soft QoS 기반의 Network Selection 단말의이동방향, 속도인식고려 어플리케이션의 QoS 요구사항인식 파워소모량 User preference Charge Service contents Fault tolerance 여러 factor 중에서단말에서 user 의입장에서가장중요한 factor 에가중치를두어지능적으로 network 선택 -46-
HPi/CDMA 연동을위한단말기구조 (Cont.) CDMA/HPi 듀얼단말프로토콜스택 -47-
결론 미래의통합망에서연동구조 Seamless vertical handover scheme 연구 Context-aware vertical handover 모듈연구 향상된 tight coupling 구조연구 Mobile IP 를적용한통합망및단말플랫폼개발중 Dual mode 탑재 Fast and power-efficient radio system discovery mechanism Preference parameters for network selection 각시스템의연동알고리즘의차이에따른재인증문제 Linux 기반의연동 testbed 구축중 통합 Gateway 개발 (WLAN+ZigBee) 단말플렛폼개발 (CDMA+HPi) -48-
결론 (Cont.) 경제적인효과 사용자편리 (Seamless Service) 이종망간의연동이필요 Ubiquitous Convergence 로가기위한초석 Cellular (e.g. HSDPA), WLAN, WMAN, WPAN, and Satellite 상호보완적인성격의연동구조 QoS 보장형연동구조 Mobile IP 기반의 seamless mobility Multi-Radio Access Tech. 간의공통자원관리 Context-aware vertical handover Soft-QoS based network selection algorithm 통합망을위한 tight coupling 제안 통합망환경에서의통합인증기술개발 연동관련국제표준화기고 Seamless handover Intelligent network selection 3GPP/3GPP2/IETF/802.16/802.11s/802.21 에연동기술기고및표준화참여 -49-
References 3GPP TS 23.234 V6.3.0, 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; 3GPP system to Wireless Local Area Network (WLAN) interworking; System description (Rel. 6) 21-05-0203-00-0000-InterDigital.doc, MEDIA INDEPENDENT HANDOVER Functions and Services Specification, IEEE 802.21 WG session #6, Jan. 2005 Salkintzis, A.K., Interworking techniques and architectures for WLAN/3G integration toward 4G mobile data networks, IEEE Wireless Communications, June 2004 Rajeev K., Fast Handovers for Mobile IPv6, draft-ietfmipshop-fast-mipv6-02.txt, July 2004 H. Soliman et al., Hierarchical Mobile IPv6 mobility management (HMIPv6), draft-ietf-mipshop-hmipv6-02.txt, June 2004 N.A. Fikouras et al., Policy Based Mobile IPv6 Handover Decision, draft-iponair-dna-polimand-01.txt, Aug. 2004 21-04-0087-07-0000, IEEE P802.21 Media Independent Handover Service Draft Technical Requirements, Aug. 2004-50-