10G-EPON Standardization and Its Development Status

Transcription

1 NThC4.pdf 2009 OSA/OFC/NFOEC G-EPON Standardization and Its Development Status Keiji Tanaka KDDI R&D Laboratories Inc. Outline 1. Background and motivation 2. IEEE 802.3av standardization 3. Research activities 4. Development status 5. Summary /09/$ IEEE 1

2 Outline 1. Background and motivation (a) FTTH growth in Japan (b) FTTH systems (c) Why 10G-EPON necessary? (d) When 10G-EPON feasible? 2. IEEE 802.3av standardization 3. Research activities 4. Development status 5. Summary FTTH growth in Japan The number of FTTH lines, more than 13 million at the end of Sep. 2008, exceeded the number of DSL lines in 2Q/2008. Number of broadband users [Million] DSL Shifted to decrease FTTH CATV Statistics as of Sep Number of lines: FTTH: 13.8 M DSL: 12.0 M CATV: 4.0 M (Mobile: 92.0 M) Number of operators: FTTH: 171 DSL: 47 CATV: Year Source: Ministry of Internal Affairs and Communications statistics database 2

3 Flavors of FTTH systems High Data rate (Bandwidth) SS WDM-PON TDM-PON Apartment Efficiency Optical access system High VDSL CPE VDSL DSLAM CO SS 100Mbit/s or 1Gbit/s Residential house Media converter Power splitter Single star Optical fiber Media converter PON Power splitter PON- Power splitter Passive double star PON topology is suitable for accommodating a lot of users and distributing broadcasting video services. Why 10G-EPON necessary? Why 10Gbps? Optical feeders with bandwidth of ~10Gbps are necessary for Advanced video services Multi-service platform to accommodate MDUs and mobile APs Why PON? PON reduces CAPEX and OPEX Accommodates a large number of FTTx users and mobile APs efficiently Reduces the footprint and power consumption of CO equipment Reduces fiber deployment and repair cost 3

4 Digital television Access network must grow beyond 1Gbps to provide advanced video services such as digital cinema. CFI, March 2006, IEEE802.3 Multi-service platform Next-generation access is expected to work as a multi-service platform in which multiple dwelling units (MDUs) and wireless access points (APs) are accommodated to reduce CAPEX and OPEX of the infrastructure. A large bandwidth is required for next-generation access network. 3.5G-mobile 10G-EPON Wireless back-haul LTE, WiFi, WiMAX 10G-EPON 10G-EPON Business users (GbE,, 10GbE) Business CMTS Cable 10G-EPON DSLAM 10G-EPON xdsl Apartment Residential users HDTV Consumer - FTTx - xdsl - Cable 4

5 When 10G-EPON feasible? 10G-EPON would be commercially feasible in 2011~2012, judging from the speed evolution of Ethernet and commercial FTTH services. 1T Transmission rate [bps] 100G 10G 1G 100M 10M 100Base-T 10Base-T 100GBase 10GBase-T/LRM 10GBase-X/R/W 10G-EPON NGA-1 Ethernet 1000Base-X/T FTTH ADSL NGA-2 1M Year Outline 1. Background and motivation 2. IEEE 802.3av standardization (a) Overview of PON (b) EPON layering diagram (c) Overview of IEEE 802.3av project (d) Ad-hoc activities in IEEE 802.3av (e) Next-generation access in ITU-T 3. Research activities 4. Development status 5. Summary 5

6 Operation of TDM-based PON Each extracts the frames destined to each selectively. (Other frames are discarded.) Optical splitter To split and combine optical signals CO Bidirectional transmission over single optical fiber All frames are broadcast to each branch. Downstream Upstream All frames are aligned so as to avoid collision Each sends frames within assigned timeslot. 2 2 Upstream nm Downstream nm Wavelength (nm) Wavelength allocation in E-/B-/G-PON /G-PON systems Customer Premise 3 3 Flavors of PONs B-PON (ITU-T) T) Ethernet frame ATM cell (53 byte) ATM cell G-PON (ITU-T) T) A fixed-length GTC frame consists of ATM cells and GEM frames. 125 s GTC frame Ethernet frame GEM frame Frames except ATM cells are contained in variable- length GEM frame GEM: G-PON encapsulation method GTC: G-PON transmission convergence EPON (IEEE) Ethernet frame Ethernet frame 6

7 IEEE802.3 layering diagram IEEE only covers physical layer and a portion of data link layer. IEEE 802.3av mainly focuses on physical layer (PMD, PMA, PCS, and RS). To be exact, IEEE802.3av slightly covers a portion of data link layer (MPCP). OSI Reference model IEEE Layering diagram Logical Link Control Scope of IEEE802.3 Application Presentation Session Transport Network Data Link Physical Control Media Access Control () Reconciliation Physical Coding Sublayer (PCS) Physical Medium Attachment (PMA) Physical Medium Dependent (PMD) Gigabit Media Independent Interface (GMII) Main scope of IEEE 802.3av Medium Dependent Interface (DMI) Medium EPON layering diagram Logical link layer topology is point-to-point with the use of logical link IDs (LLIDs), although physical media topology is point-to-multipoint. LLID #1 LLID #N #1 #N Mac Client OAM MPCP Mac Client OAM Mac Client OAM MPCP Mac Client OAM MPCP Point-to to-point RS RS RS PCS PMA PMD PCS PMA PMD PCS PMA PMD Optical fiber Optical splitter Optical fiber Point-to to- multipoint 7

8 Frame format in EPON LLID for logical topology emulation is embedded in the preamble portion of Ethernet frame (IEEE802.3 frame). 8 octet Preamble / SFD Destination Address Source Address Type Data FCS SFD 0x55 0x55 0x55 0x55 0x55 0x55 0x55 0xd5 Ethernet SLD 0x55 0x55 0xd5 0x55 0x55 LLID LLID CRC8 Format of frame preamble in EPON EPON SFD: Start of Frame Delimiter FCS: Frame Check Sequence SLD: Start of LLID Delimiter LLID: Logical Link Identifier CRC8:8bit Cyclic Redundancy Check IEEE802.3av project What 10G-EPON? 10x higher-speed standard of IEEE802.3 EPON IEEE 802.3av mainly focuses on physical layer for 10Gbps transmission. (Formerly named 10Gbps PHY for EPON ) Frame format,, OAM are basically the same as IEEE802.3 EPON. Timeline Expected standard approval : September P802.3av Study Group CFI PAR Draft0.9 Task force Draft1.0 Draft2.0 Draft3.0 Std Project start Baseline proposal 1 st draft Last feature Last tech. change CFI : Call For Interest PAR : Project Authorization Request 8

9 Objectives of IEEE802.3av Support subscriber access networks using point to multipoint topology ology on optical fiber Fully compatible with existing ODNs PHYs to have a BER better than or equal to at the PHY service interface Provide physical layer specification - PHY for PON, 10Gbps downstream / 1Gbps upstream, single SM fiber - PHY for PON, 10Gbps downstream / 10Gbps upstream, single SM fiber Asymmetric 10G-EPON Symmetric 10G-EPON 10Gbps 1Gbps 10Gbps 10Gbps Define up to 3 optical power budgets that support split ratios of 1:16 and 1: 32, and distances of at least 10 and at least 20 km. 10km 20km 1:16 PR10, PRX10 PR20, PRX20 1:32 PR20, PRX20 PR30, PRX30 Co-existence Co-existence issues are seriously considered in IEEE802.3av specifications: Co-exist with deployed systems of 1G-EPON and RF video on the same ODN Reuse of deployed optical distribution network (ODN) (1) To co-exist with 1G-EPON and RF video, the followings are adopted: - Downstream : WDM (L-band) - Upstream : 10G/1G dual-rate TDMA (2) For the reuse of deployed ODN, a new power budget class is specified: - PR/PRX30 (Loss budget : 29dB) Downstream RF-Video PON- RF-Video (1.55mm) 10G (L-band) 1G (1.49mm) V- 10G/10G 10G/1G 1G Dual-rate Burst Rx 1G(1.31mm) 10G(1.27mm) 1G/1G Upstream 9

10 Main differences between 1G- and 10G-EPON channel coding (coding overhead) data rate (DS/US) split ratio 1G-EPON 8B10B (25%) 1G/1Gbps-symmetric 1:16 10G-EPON 64B66B (3%) 10G/10G-symmetric + 10G/1G-asymmetric 1:16 / 1:32 (*1) # of power budget class FEC 2 (PX10 / PX20) option RS(255, 239) 3 (PR10 / PR20 / PR30) mandatory RS(255, 223) wavelength US 1260 ~ 1360 nm 1260 ~ 1280 nm (*2) DS 1480 ~ 1500 nm 1575 ~ 1580 nm (*1) only for PR/PRX30 (*2) asymmetric 10G-EPON : 1260 ~ 1360 nm Ad-hoc activities in IEEE802.3av P802.3av Power Budget High-split Power Budget Jitter Budget FEC FEC Framing Rate Increase Analysis Wavelength Wavelength Allocation Others Dual-rate PMD Power Saving CFI PAR Draft0.9 Study Group Draft1.0 Draft2.0 Draft3.0 Std Task Force 10

11 Power budget (1) P802.3av CFI PAR Draft0.9 Study Group Draft1.0 Draft2.0 Draft3.0 Std Task Force Power Budget Long discussion on PR30 technologies Parameter modifications Main point of the argument : technologies for PR/PRX30 class Two solutions were considered: (1) PIN-PD@ (w/o optical amp.@) (2) APD@ (high-power EML@) Lower output power solution at is preferable in terms of safety and crosstalk to RF-video systems Small footprint at APD@ solution was adopted for PR/PRX30. Total optics cost 3av_0709_hamano_1.pdf, IEEE 10G-EPON Task Force Power budget (2) Downstream l = 1575 ~ 1580 nm PR30 HP-EML db (1.5dB-Penely included) APD w/ FEC PR20 EML+Amp db (1.5dB) PIN w/ FEC PR10 HP-EML db (2.5dB) PIN w/ FEC HP : High Power Upstream PR30 HP-DML db -28 (3dB-Penely included) APD w/ FEC PR20 PR10 DML DML l = 1260 ~ 1280 nm db (3dB) db (3dB) APD w/ FEC APD w/ FEC HP : High Power 11

12 Power budget (3) Downstream Upstream PR10 PR20 PR30 PR10 PR20 PR30 Transmitter type EML EML+SOA EML DML DML DML Tx max [dbm] Tx min [dbm] ER [db] Receiver type PIN PIN APD APD APD APD Sens. [dbm] Power budget [db] CIL [db](*1) (*1) channel insertion loss (CIL) = power budget path penalties FEC FEC was considered mandatory for 10G-EPON systems to relax optical transceiver specifications. In terms of practicality and simplicity, RS(255, 223) was chosen because additional 1 db optical gain to conventional RS(255, 239) is necessary for PR/PRX30 power budget classes. RS(255, 223) was adopted to obtain enough power margin for PR/PRX30. RS(255,239) vs. RS(255, 223) Decoded BER characteristics Code RS(255,239) RS(255,223) Bit rate Electrical coding gain Required BER for BER= Gpbs 5.9 db 1.8x Gbps 5.9 db 1.8x Gbps 7.2 dg 1.1x10-3 Circuit size (*1) 16 encoder 1 8 decoder (*1) 3av_0709_mandin_2.pdf, IEEE 10G-EPON Task Force 12

13 Wavelength allocation (1) CFI PAR Draft0.9 Draft1.0 Draft2.0 Draft3.0 Std P802.3av Study group Task force Wavelength Allocation Upstream Downstream 1260~80 L-band PR10/ ~ ~ ~ ~80 PR30 Possible Wavelength for 10G-EPON systems Restricted by wavelength separation filter property Possible DS wavelength : L-band Cut-off wavelength GE-PON (US) GE-PON (DS) Video OTDR l Restricted by the blocking filter property (G.984.5) Wavelength allocation (2) : upstream FP-LD is not applicable to 10G- even at 1.3m-band. A 20-nm bandwidth is enough for 10Gupstream wavelength band on the condition that DFB-LDs are adopted. It is preferable that 10G-EPON PHYs are identical to ITU-T specifications. Dispersion penalty should be minimized. Wavelength band in G.984.enh (G.985) 3av_0705_effenberger_3.pdf, IEEE 10G-EPON Task Force Upstream wavelength band 20nm PR10/20/30 100nm PRX10/20/ Power penalties at 1.3m-band 13

14 Wavelength allocation (3) : downstream The specification of BPF in to separate RF video signal: Isolation : 35dB Guard band of BPF Video Downstream wavelength band The shortest wavelength is bound by the characteristics of the optical BPF. The guard band of the filter should be longer than 15nm. The longest wavelength is bound by conventional ITU-T recommendations such as G.982 and 983, in which the signal wavelength range shall be less than 1580nm. In addition, OTDR filter problem, which is operator-specific one, is not expected in this wavelength range Downstream wavelength band 1575 ~ 1580nm for all PMD classes Dual-rate PMD (1) PCS and RS for dual-rate mode at 1G/1G 10G/1G 10G/10G Three kinds of s of 1G/1G, 10G/1G and 10G/10G are supported. RS PCS GMII Tx 1Gb/s Tx Path Rx 1Gb/s Rx Path XGMII Tx 10Gb/s Tx Path Rx 10Gb/s Rx Path RS maps downstream data from instances to appropriate downstream path according to LLID. The operation for upstream data is similar to downstream direction. PMA PMD 802.3ah sublayers av sublayers As dual-rate PMD, two solutions are considered. 14

15 Dual-rate PMD (2) The incoming dual-rate signals from s to PMD at can be split in (a) optical domain, or (b) electrical domain. Optical domain Electrical domain 10G detector 10G TIA and LA 10G LA 1x2 splitter Dual-rate TIA optical amplifier (optional) 1G detector 1G TIA and LA Dual-rate PD 1G LA 3dB-loss in 1x2 splitter - Acceptable in PR10/20 - Challenging in PR30 Two dedicated Rx circuits Simple configuration PD and TIA cope with both data rates in quick succession, switching 1G and 10G bursts. Next-generation access in ITU-T The development of next-generation access (NGA) standards will be held in the next ITU-T study period from 2009 to Now ~2010 ~2015 NGA1 NGA2 ITU-T FSAN B/G-PON Extended reach TDM XG-PON (US: 2.5, 5, 10G / DS: 10G) WDM overlay G-PON (US: 2.5, 5, 10G / DS: 10G) Higher rate TDM DWDM OFDM etc Co-existence Use of common equipment ODN Existing ODN (no replacement and additional component) New ODN 15

16 Outline 1. Background and motivation 2. IEEE 802.3av standardization 3. Research activities (a) Optical transceiver technologies (b) Asymmetric system (c) Symmetric system 4. Development status 5. Summary Optical transceiver technologies The latest reported results on optical transceiver technologies are as follows: Transmitter Main performance 0.5ns response +4.4dBm-output power 6ns turn-on/off time +3.3dBm output power Receiver Main performance 160bit CID tolerant CDR 10ns instantaneous response -19.5dBm sensitivity 20.5dB dynamic range 50ps synchronization time 72 bit CID tolerant CDR 1.25/10.3-Gbps dual-rate burst-mode receiver Reported at / from OFC 08 NTT OFC 08 Mitsubishi Reported at / from ECOC 07 NTT ECOC 07 NTT ECOC 08 Yokogawa ECOC 08 Mitsubishi ECOC 08 NTT Applied technologies AC-coupled differential interface using BLW-CMR technique Impedance-controlled DC-coupled burst-mode LD driver circuit Applied technologies Single-VCO architecture Burst-mode PIN-TIA Automatic offset compensation (2-stage) Cascade-type burst CR circuit Quad-rate sampling Two gate circuits AC-coupled interface No reset signals 16

17 Asymmetric system Main performance 10G/1G-EPON demonstration 128-split, 10km-system G-/10G-PON mixture system Seamless upgrade 10G/2.5Gbps demonstration 10G/2.5Gbps GPON coexistence for downstream Reported at / from IEEE802.3 ETRI CFI ECOC 07 ECOC 07 ECOC 08 Fujitsu NSN Alcatel- Lucent Applied technologies DS synch-protection mapping Electrical multiplexing 2.5Gbps burst receiver Downstream bit-stacking by using electrical multiplexing Feasibility test of 10G/1G-EPON DS: 10Gbps, US: 1Gbps Split : 128 Distance : 10km CFI, March 2006, IEEE Symmetric system Main performance 4Gbps US throughput 23dB power budget w/o FEC 9.7Gbps US throughput 32-LLIDs >9Gbps US throughput >30dB power budget (PR30) Reported at / from ECOC 05 KDDI OECC 07 Mitsubishi ECOC 08 KDDI Applied technologies XENPAK-based burst-mode Tx/Rx FPGA-based PON IEEE802.3 MPCP PR30 compliant burst-mode Tx/Rx FPGA-based PON XFP 10GbE (FPGA) 10G-EPON (FPGA) Tx Optical (EML) Transceiver Rx WDM 10G-EPON prototype WDM Tx (DML) Tx Optical (DML) Transceiver Rx 10G-EPON (FPGA) 10GbE (FPGA) XFP -1-2 Burst control signal 17

18 Outline 1. Background and motivation 2. IEEE 802.3av standardization 3. Research activities 4. Development status (a) Chipset (b) Key devices for 10Gbit/s burst-mode transmission (c) Equipments for asymmetric 10G-EPON system 5. Summary Chipset EPON chip vendors start the delivery of 10G-EPON evaluation board. PMC-Sierra The PAS8001 and PAS9001 deliver 10Gbit/s performance, pre-standard (draft 1.1) IEEE 802.3av compliance, 1G/10G co-existence with auto-detect, standard encryption, high-performance backward-compatible Dynamic Bandwidth Allocation (DBA) and commercially viable transceivers developed by a leading transceiver vendor partner. Press Release (Mar. 31, 2008) Teknovus Teknovus 10G EPON evaluation board system (EVB) is compliant with the latest draft of the IEEE 802.3av 10G EPON standard. In addition to the IEEE 802.3av feature set, the 10G EPON EVB system supports triple-lambda wavelength-division multiplexing (WDM) downstream operation at 1.25G, 2.5G and 10G simultaneously. Press Release (Nov. 18, 2008) 18

19 Key devices for 10Gbit/s burst-mode transmission Transmitter XFP module size (78x18.3x8.2mm) Output power : +7.0dBm Extinction ratio : 7.1dB Mask margin : 29% Turn_on/off : 6/0 ns Receiver 10.3 Gbps quad-rate sampling burst-mode CDR Quad-rate sampling IC 0.13m SiGe BiCMOS 6.6x6.3mm size 1.9W power consumption Burst response CID : 72-bit 1 st -bit burst-mode recovery Courtesy Mitsubishi Electric Corporation Asymmetric 10G-EPON system ATCA300 universal architecture High-speed backplane FPGA-based PON- SFP-sized optical transceiver Mesa-type APD FPGA-based PON System features Asymmetric 10G-EPON system (Downstream: 10Gbps, Upstream : 1Gbps) Compliant with IEEE802.3av draft2.0 Co-existence with 1G-EPON (IEEE802.3ah) Loss budget (channel insertion loss) : > 30 db Maximum distance : 20km 32 subscribers per PON interface Superior QoS to subscribers and services Courtesy NEC 19

20 Outline 1. Background and motivation 2. IEEE 802.3av standardization 3. Research activities 4. Development status 5. Summary Summary Why 10G-EPON? Optical feeders with bandwidth of 10Gbps are necessary for next-generation access system, and PON topology is expected to reduce CAPEX and OPEX. Standardization Draft2.2 was issued after November 2008 meeting, and the standard d is expected to be approved in September IEEE802.3av mainly focuses on physical layer specifications. Research and development activities Feasibility studies on key components and systems have been reported. rted. EPON chip vendors and system vendors have been developing evaluation boards and proto-type type systems. Challenges toward commercial products Reduction of cost, size, and power consumption of optical transceivers Interoperability on optical transceiver and chip 20