ETRI, 2005 www.etri.re.kr WiBro 표준동향과 MAC 기술 2005. 2. 15. 이동통신연구단휴대인터넷시스템연구그룹휴대인터넷표준연구팀윤철식
1. 휴대인터넷서비스및요구사항 -2-
휴대인터넷서비스및요구사항 Portable Internet Service Easy connectivity: anywhere and anytime internet access High-speed Data: about high-speed wireline internet Low mobility : nomadic user Terminal : notebook, handheld PC, PDA, smart phone, etc. HPi Service Positioning Tx Rate High- Speed Internet Wirelss LAN 4G Mobile Communication HPi Internet 3G Mobile Communication Fixed Low Mobility Mobile Mobility Low Cost HPi (Nomadic User) Service High Tx Capacity Mobility -3-
휴대인터넷시스템 / 서비스요구사항 Service Definition Portable Internet Service is to provide a high data rate wireless internet access with PSS under the stationary or mobile environment, anytime and anywhere. Service Concept Under the stationary or mobile environment: service shall support stationary, nomadic, and medium-speed mobile users. Anytime and anywhere: service shall provide seamless connectivity regardless of the place and time. High data rate: service shall support the various types of wireless multimedia applications with a data rate of at least 1 Mbps. PSS (Portable Subscriber Station): service shall support the various types of multimedia-enabled terminals such as handset, notebook, PDA, or smart phone. -4-
Service Classes Real-time service Definition: Service which imposes delay constraints while requiring the guaranteed resource allocation during the session. Examples: audio/video streaming, interactive game Non-real-time service Definition: Service which does not impose any delay constraints while requiring the guaranteed resource allocation during the session. Examples: FTP, Multimedia mail, chatting, e-commerce Best-effort Service Definition: Service which does not impose any delay constraints while requiring no guaranteed resource allocation during the given service. Examples: Web browsing, e-mail -5-
Service Requirements Cell types: Pico, Micro, Macro (for Urban environment) Service coverage: the following cell radius must be supported for the different cell types in the urban environment. Pico-cell: 100 m Micro-cell: 400 m Macro-cell: 1km Mobility: System shall support mobile users at a velocity of up to 60 km/hr. Handoff: System shall support seamless IP-based service while users move from one cell to other. Authentication and Security System shall prohibit unlawful usage and unlawful access network service except lawful user and terminal. -6-
Service Requirements (cont.) QoS (Quality of Service): System shall provide different types of QoS, depending on subscriber s service classes. Charging: System shall provide various basic data to support various charging rate, depending on subscriber s need. Interworking with other network systems System shall support interworking with other network systems such as wireless LAN and other mobile communication networks, etc. -7-
Access Network Requirements & Parameters Frequency reuse factor: FRF = 1 Spectral efficiency (bps/hz/cell): Maximum spectral efficiency: Downlink = 6, Uplink = 2 Average spectral efficiency: Downlink = 2, Uplink = 1 Transmission data rate Minimum transmission data rate per user: Downlink = 512 kbps, Uplink = 128 kbps Maximum transmission data rate per user: Downlink = 3 Mbps, Uplink = 1 Mbps Handoff requirements Inter-sector handoff: < 150 msec Inter-cell handoff: < 150 msec Average throughput (bps/hz/cell) Downlink = 2, Uplink = 1-8-
PSS Requirements & Parameters Power saving function PSS shall support a power saving function to minimize the power consumption. Mobility support PSS shall support IP-based seamless service when it moves to another cell. Multicast/Broadcast PSS shall be able to receive multicast/broadcast data transmitted from the network. Interworking with other networks PSS shall be able to provide an appropriate method to control the connection when interworking with other networks. Authentication and Security MSS shall support the authentication /security protocol based on EAP. If necessary, the PKI-based protocol shall be supported. Various cryptographic functions shall be provided. -9-
휴대인터넷시스템특성 Item W-LAN HPi IMT-2000 Service type -Packet based - High-speed data - IP originating call -Packet based - High-speed data -IP based call - Circuit/Packet based - Medium/Low-speed data - Originating/Terminating call Service characteristics -Private - No QoS guarantee ( BW contention ) - Public - QoS guarantee ( BW allocation ) - Public - QoS guarantee ( BW allocation ) Tx. rate - Maximum 54Mbps - Maximum 50Mbps - Maximum 2,or 10Mbps Cell coverage - Coverage : 100m -pico(hot spot area) - Coverage : 1Km -micro/pico(full coverage) - Coverage : 10Km - macro/micro(full coverage) Mobility - Fixed (Coverage) - Low mobility(60km) - High mobility (250Km) Cell planning -no - Frequency reuse (~1) - Frequency reuse (~1) Cell capacity -54Mbps -50Mbps -2Mbps(Ev-DO) -10Mbps(HSDPA) Cell structure -omni - 1 to 3 sector - 1 to 3 sector Terminal - PC, Note-book, PDA - Note-book, PDA - Cellular phone, PDA -10-
2. 휴대인터넷표준화현황및서비스일정 -11-
휴대인터넷표준화현황 IEEE 802.16 표준화현황 IEEE 802.16 (~2001) 10-66 GHz 대역에서 LOS (Line-of-Sight) 환경에서 Fixed Wireless 사용자에대한서비스를제공하기위한시스템의규격 PHY(SC) 및 MAC 규격의개발 (DOCSIS 규격으로부터많은부분을차용 ) IEEE 802.16a (~ Apr. 2003) 2-11 GHz 대역에서 NLOS (None-Line-of-Sight) 환경에서 Fixed Wireless 사용자에대한서비스를제공하기위한시스템의규격 SCa, OFDM, OFDMA의 3가지새로운 PHY 규격을포함하였고, PHY-specific MAC 규격에대하여최소한의부분만을규정하며, 최대한동일 MAC 규격으로유지하기위한규격 IEEE 802.16c (~ Jan. 2003) 시스템간 interoperability 를제공하기위한 10-66 GHz 시스템 profile 을정의하는규격 IEEE 802.16d (RevCom Approval, June. 2004) 16 + 16a + 16c 를통합한 (consolidated) 규격으로서작성되며, 기존규격의 enhancement 를지향하는규격 IEEE 802.16-2004 Standard 로서확정 (2004. 6.) IEEE 802.16e (Working Group Ballot, June. 2004) 802.16d 를기반으로하여, 이동성을제공하기위한규격의 amendment 를규정하는규격 -12-
휴대인터넷표준화현황 IEEE 802.16 표준화현황 고정형규격개발 (TGd): IEEE Standard 802.16-2004 published on 1 Oct. 2004. IEEE Standard for Local and metropolitan area networks Part 16: Air Interface for Fixed Broadband Wireless Access System As a revision of IEEE Standard 802.16-2001 (as amended by IEEE Standard 802.16c-2002, and IEEE Standard 802.16a-2003). 이동성지원규격개발 (TGe): During the Process of Sponsor Ballot Resolution IEEE-SA Standard Board approved a modified project authorization (PAR) for P802.16e project on 23 Sept. 2004. Comment resolution at Session #35 (Sanya, Hainan, China on Jan. 24-27, 2005) to a Comments raised during the P802.16e/D5a BRC Recirculation. Plan to complete in the second quarter of 2005. -13-
IEEE 802.16 표준화현황 (cont.) IEEE P802.16e Draft Development Schedule (Plan for June 2005 Approval) 2005/02/11: Issue P802.16e/D6 2005/02/14-03/01: P802.16e/D6 Sponsor Ballot Recirculation 2005/03/14-17: Comment Resolution at IEEE 802.16 Session #36 2005/03/18: Conditional Approval from 802 EC to submit to RevCom 2005/04/01: Issue P802.16e/D7 2005/04/04-04/19: P802.16e/D7 Sponsor Ballot Recirculation 2005/04/29: Submit approval application to RevCom (deadline) 2005/06/08: RevCom recommends approval of P802.16e/D7 2005/06/09: IEEE SA Standard Board approves IEEE Std 802.16e 2005/07: IEEE Std 802.16e published -14-
휴대인터넷표준화현황 IEEE 802.16 표준화현황 망관리규격개발 (TGf - MIB): Third draft of Management Information Base (MIB) was made. The Working Group agreed to seek approval to forward Draft 3 for Sponsor Ballot. 망관리규격개발 (TGg - Management Plane Procedures and Services): Approved the Baseline document and resolve the comments raised. Maintenance 규격개발 (Corrigendum): The IEEE-SA Standard Board approved a PAR creating a corrigendum project P802.16-2004/Cor1 for maintenance of IEEE Standard 802.16. Plan to complete in May 2005. -15-
휴대인터넷표준화현황및일정계획 TTA 표준화현황 2004. 6 : TTA Phase-I 규격승인 2004. 12 : TTA Phase-I 규격의 IEEE 802.16규격과의호환성유지를위한 1단계규격수정안승인 2005. 1Q : TTA Phase-II 규격의요소기술제안및평가 2005. 2Q : TTA Phase-II 규격승인목표 2005. 1 : TTA 무선접속실무반내에 IOT/CT Task Force 구성 2005. 1Q : IOT Basic Profile 작성완료 2005. 2Q : IOT/CT Specification 작성완료 2005. 3Q : IOT/CT Specification 보완 2005. 4Q : 사업자 /TTA 중심으로시험규격작성및 CT 진행 -16-
휴대인터넷추진일정 휴대인터넷추진일정 : 2004. 7 : 정보통신부휴대인터넷추진일정및기술방식확정 IEEE 802.16-2004 및 P802.16e/D3 이후버전을만족하는규격으로서하기 5 가지요구사항을만족하는규격 이중화방식 : TDD 주파수재사용계수 : 1 채널대역폭 : 9 MHz 이상 이동성 : 시속 60 km/hr 최소전송속도 : UL 128 kbps, DL 512 kbps 2005. 1 : 휴대인터넷사업자선정 KT, SK Telecom, Hanarotelecom 등 3 개사업자조기선정 2005. 12 : 상용장비개발완료 각장비 ( 시스템, 중계기, 단말기등 ) 개발업체 2005년말또는 2006 1Q에상용시스템개발완료및시험예정 2006. 1Q : 시범서비스 2006. 4 : 상용서비스시작 (KT, 서울 / 수도권지역 ) -17-
3. 휴대인터넷 MAC 기술 -18-
MAC Protocol Layer Structure MAC PHY CS SAP Service Specific Convergence Sublayer (CS) MAC SAP MAC Common Part Sublayer (MAC CPS) Privacy Sublayer PHY SAP Physical Layer (PHY) Service Specific Convergence Sublayer (CS) Transformation or mapping of external network data Received through the CS SAP into MAC SDUs received by the MAC CPS through the MAC SAP. This includes classifying external network SDUs and associating them to the proper MAC service flow and CID. Payload header suppression. The internal format of the CS payload is unique to the CS The MAC CPS is not required to understand the format of or parse any information from the CS payload. The MAC CPS Core MAC functionality of system access, Bandwidth allocation Connection establishment Connection maintenance Classified to particular MAC connections. Quality of Service (QoS) Scheduling of data over the PHY. Privacy Sublayer Providing authentication Secure key exchange Encryption. -19-
MAC PDU Header Format Generic MAC Header Format Bandwidth Request Header Format -20-
MAC PDU Construction PHSI Packet PDU PHSI Packet PDU Bandwidth Request PDU MAC SDU MAC SDU MAC SDU #1 MAC SDU #2 BR Header User PDU Fragmentation MAC Header MAC SDU CRC MAC SDU MAC SDU Management PDU MAC PDU Packing MAC Header Management Message Type MAC PDU MAC Management Payload MAC Header Fragmentation Sub-header MAC SDU f1 MAC Header Fragmentation Sub-header MAC SDU f2 MAC PDU MAC PDU MAC Header Packing Sub-header MAC SDU Packing Sub-header MAC SDU MAC PDU -21-
ARQ Mechanism ARQ (Automatic Repeat request) MAC Layer 의 optional 기능 Connection 설정시 ARQ 사용여부결정 per-connection basis 로서수행 Cumulative/Selective ACK 를가지는 Selective Repeat ARQ Bitmap 방식으로서 Bitmap Block 의크기를가변적으로운용가능함 Sliding Window Protocol TX FSN ARQ_TX_WINDOW_START ARQ_TX_WINDOW_START + ARQ_TX_WINDOW_SIZE ARQ Parameters FSN: Fragmentation Sequence Number Fragment Transmission ACK/NACK - Standalone Message - Piggybacked Fragment Retransmission ARQ Discard message RX FSN ARQ_RX_WINDOW_START ARQ_RX_WINDOW_START + ARQ_TX_WINDOW_SIZE - ARQ_FSN_MODULUS - ARQ_WINDOW_SIZE - ARQ_FRAGMENT_LIFETIME - ARQ_RETRY_TIMEOUT - ARQ_SYNC_LOSS_TIMEOUT -22-
SS Initialization Overview -23-
Frame Structure (TDD Mode with only mandatory zone) -24-
Usage of MAP & Dedicated Feedback Channels Channel Transmission Information Downlink Frame Uplink Frame Tx. Period Remarks FCH Frame Control Header Every Frame General MAP pointing General MAP General MAP information Every Frame Compact MAP pointing Compact MAP (HARQ based) User data burst allocation Every Frame MAP AMC support Diversity Traffic Burst Traffic/Messages Traffic/Messages - Band AMC Safety Channel CQICH Channel Quality Periodic If allocated ACKCH H-ARQ Ack - Implicit Ranging CH Ranging Codes - Uplink synchronization -25-
Resource Allocation (Example: H-ARQ H MAP) Basic CID, Nep, Nsch for MSS #A Basic CID, Nep, Nsch for MSS #B FCH Compact MAP 1 MAP IE MAP IE DL Burst #1 DL Burst #3 DL Burst #5 CQI CH UL Burst #1 General MAP Compact MAP 2 MAP IE DL Burst #6 ACK CH UL Burst #2 Compact MAP 3 MAP IE MAP IE DL Burst #2 DL Burst #4 DL Burst #7 Ranging Subchannel UL Burst #3 : HARQ_Pointer_IE Basic CID, Nep, Nsch for MSS #D Basic CID, Nep, Nsch for MSS #C -26-
Ranging and Bandwidth Request Messaging 방식 CDMA 방식 Initial Ranging Contention-based Contention-based Ο 1 Unicast-polling Unicast-polling Periodic Ranging Contention-based Contention-based Ο 2 Unicast-polling Ο Unicast-polling Bandwidth Request Contention-based Unicast-polling Ο Contention-based Unicast-polling Ο 3 Ο 1 : CDMA-based Ranging (status = success 인 RNG-RSP 수신 ) 후, CDMA_Allocation_IE 에할당된 UL 구간으로 RNG-REQ (with MAC Address) 메시지전송 Ο 2 : CDMA-based Ranging 절차만계속 (status = success 가될때까지 ) Ο 3 : CDMA-based Bandwidth Request 용 Code 전송후, CDMA_Allocation_IE 에할당된 UL 구간으로 BW Request Header and/or UL Data 전송 -27-
HO PROCEDURES Inter-Sector (MSS initiated) Inter-BS (MSS initiated) -28-
NBR-ADV AND CELL RESELECTION 방송정보주기 Trade-off Acquisition time Broadcast data overhead -29-
HO PROCESS OPTIMIZATION Network Re-entry Procedure NBR-ADV : 인접셀능력 HO-RSP : 망이추천한셀능력 RNG-RSP : HO 하는셀능력 -30-
IEEE 802.16e : Active BS Add (Example) Active Set Update Active BS Addition BS 1 Addition BS 2-31-
IEEE 802.16e : FAST BS SWITCHING Fast Anchor BS Selection Feedback Channel 사용 CQICH 내 8 개 code word 를사용하여셀을선택. BS 1 BS 2 BS 1 BS 2-32-
Idle Mode Idle Mode Concept: MSS가여러BS가관장하는 air interface를돌아다니면서특정한 BS에 registered 되지않고도주기적으로 DL broadcast messaging을받을수있도록하기위한것으로서, Idle mode에있는mss는 Handover나 Normal operation에따르는active requirement를지키지않아도됨 Discrete interval에만호출여부를점검하며 power save를할수있는상태 Conditions: 모든 connection (user service) 및 management connection ID 들은해제 / 반납됨 IP address 도반납된다. MBS service는추가적인dsx 절차없이도제공받을수있음 Idle Mode Entering procedure: BS-initiated unsolicited DREG-Cmd message (Code = 0x05) MSS-initiated DREG-REQ, then the BS shall Tx DREG-Cmd (Code 0x05). Paging and Location Update Paging Group ID, Paging Cycle, Paging Offset 값에의해 Paging interval 동안에 paging 가능 (Paging Controller/serving BS 에의하여 ) Paging 된 MSS 에대해 RNG-REQ/RSP 메시징을통하여 Location Update 가능 -33-
MBS (Multicast and Broadcast Service) MBS Concept MBS: (Multimedia) multicast/broadcast Service 를말하며, 여러개의 BS 들에의한 synchronized transmission 을통하여별도의 network entry 절차를거치지않고도다수의 BS 에걸쳐 seamless multicast/broadcast service 를제공하는것 MBS_Zone: 하나의 MBS service flow 에대하여 CID 및 SA 가유효한영역을나타냄. 하나의 BS 는여러개의 MBS Zone 에대응될수도있음. MBS Security Association MBS Group Security Association (MBS GSA) 는 BS 에서 provisioned 되어야함. MBS GSA 의 shared information 에는 Cryptographic suite 와 Key materials (MBS Authorization Key; MAK, & MBS Group Traffic Encryption Key; MGTEK) 및그들의 lifetime 등이포함됨. MBS Traffic Encryption AES CTR Mode [NIST special publication 800-38A, FIPS 197] PDU payload shall be prepended with a 32-bit nonce (used as a 128 bit nonce with repetitively concatenated). The plaintext PDU shall be encrypted using the active MBS_Traffic_Key (MTK) derived from MAK and MGTEK, according to CTR specification. MTK = Dot16KDF(MAK, MGTEK, 128) -34-
Cell-based Multicast Service vs. Seamless Multicast & Broadcast Service (MBS) (1) CID Use: Cell-based: Unicast connection과동일한region에있는 ( 특별히구분되지않는 ) transport connection을공유한다. 해당 CID의할당은BS의자체권한. MBS: 특정한 region에있는dedicated multicast CID들을사용하며, 동일한 MBS_Zone에속하는BS에서모두동일한 CID를사용하여 MBS traffic을전송한다. CID의할당은 centralized controller (such as MBS Content Server) 등에의하여관리됨. Macro-diversity Gain: Cell-based: 특정 cell 내에서 multicast service에 join 된모든SS에대하여전송하므로사실상가장 robust한 burst profile을사용하여야한다. MBS: MBS_Zone 내의인접한 BS들에서동일한데이터 ( 동일한 PDU header 및 payload; 동일한 channel coding 및변조방식사용 ) 를동일한심볼구간및 carrier로전송하므로 diversity gain을얻는다. Registered or not: Cell-based: 특정 cell (BS) 에 registered 되어있어야만하며, DSA 절차에의한 Join 과정으로접속된다. MBS: 특정 cell에 registered 되어야만하는것은아니며, Idle Mode나 Sleep Mode에서도 MBS service를유지할수있다. -35-
Cell-based Multicast Service vs. Seamless Multicast & Broadcast Service (MBS) (2) SA Capabilities: Cell-based: 특정한 Multicast 용 static SA 또는 dynamic SA 에 mapping 될수있음. Primary Management connection 에의한 key update 가능. MBS: MBS 용 GSA, 즉, MBS-GSA 과 mapping 됨. Idle Mode 에서는모든 management connection 이반환되므로, key update 에대한방법론이명확하지않음 ( 미해결과제 ). Data Encryption Cell-based: MAC layer encryption 만정의되며, 기존의 data encryption algorithm 중어느것도사용가능함 MBS: application layer 또는 MAC layer 에서의 data encryption 둘다지원. MAC encryption 은 AES-CTR mode 만사용가능함 (When the data encryption identifier in the cryptographic suite of an MBS GSA = 0x80). Power Saving Operation Cell-based: 특정 multicast service 에대한 periodicity 가보장되지않으므로별도의 power saving 효과를기대할수없음. MBS: MBS-MAP 을사용하여 MBS burst 들에적용될 physical attributes 뿐만아니라각각의 connection 에대한다음에전송될프레임및그프레임에서의위치에대한정보도제공한다. 이에따른 scheduling 을통하여 power saving 을극대화할수있다. -36-
4. IEEE 802.16 Session #35 Results: MAC (2005-01, 01, Hainan,, China) -37-
SUB-UL- MAP MAP Normal MAP Extension for H-ARQH Support H-ARQ and Multiple Maps in the Normal Map OFDMA symbol number k k+1 k+3 k+5 k+7 k+9 k+11 k+13 k+15 k+17 k+19 FCH SUB-DL- MAP UL-MAP DL burst #4 Subchannel logical number Preamble DL-MAP SUB-DL- MAP Sub-UL- MAP DL burst #3 DL burst #1 DL burst #5 DL burst #6 SUB-DL-MAP SUB-UL- DL burst #2 DL burst #7 slot mapping order for DL map messages -38-
Normal MAP Extension for HARQ Optimizing IE overhead of H-ARQ burst allocation DL map IE Compressed DL & UL MAP H-ARQ burst 1 H-ARQ burst 2 H-ARQ burst 3 H-ARQ burst 3 H-ARQ burst 4 H-ARQ burst 2 H-ARQ burst 3 H-ARQ burst 4-39-
PKMv2 Key Hierarchy -40-
PKM Procedure SS BS AAA SBC-REQ (Authorization Policy Negotiation) SBC-RSP Regacy PKM PKM-REQ/Authentication Information PKM-REQ/Authorization Request PKM-RSP/Authorization Reply PKMv2-EAP PKM-REQ/EAP-transfer (EAP Payload). PKM-RSP/EAP-transfer (EAP Payload) PKM-REQ/key request PKM-RSP/key reply (TEK key, sequence number, IV) Diameter(EAP-TLS) Diameter(EAP-TLS) EAP-TLS User Authentication and AK Distribution base on EAP-TLS 3-way EAP Keying 을위한 Security Capabilities Negotiation & Handover 시 TEK Update 를포함하는를교환하기위한메시지가추가로정의됨 SA-Challenge/SA-TEK-Request/Response message -41-
FAST AUTHENTICATION (PKMv1) Old BS AK <> New BS AK Old BS AK = New BS AK BS간동일사업자이고, 보안유지 -42-
PRE-AUTHENTICATION (PKMv2) Old BS AK <> New BS AK PMK and/or PAK in old BS AK generated from PMK and/or PAK in new BS -43-
Q & A Thank you for your kind attention -44-