More on Super-PON. Scale Fully Passive Optical Access Networks to Longer Reaches and to a Significantly Higher Number of Subscribers

Transcription

1 More on Super-PON Scale Fully Passive Optical Access Networks to Longer Reaches and to a Significantly Higher Number of Subscribers Claudio DeSanti Liang Du

2 Agenda Refinements 2.5G-EPON Upstream Speed Considerations Claudio DeSanti 2

3 Super-PON Architecture Complete 1 OLT 10G-EPON l1 MUX/Amplifier 2 n OLT 10G-EPON l2 OLT 10G-EPON lm Pt2Pt 10G l1 Pt2Pt 10G l2 MUX DMUX booster preamp BAND MUX... m+q Cyclic AWG... P2P 1 P2P 2 P2P q A: up to 40 Km B: up to 20 Km A + B 50 Km 1 2 n 1 Pt2Pt 10G lq CO n Claudio DeSanti 3 2

4 Super-PON Residential OLT OLT TP1 TP2 TP3 TP4 Active Optical MUX/Amp TP11 TP12 TP5 TP6 Channel: Fiber Optic Cabling Optical MUX/Amp Cyclic AWG Optical Splitter Passive Cyclic AWG Claudio DeSanti 4 Passive Optical Splitter Passive Optical Splitter Fiber optic cabling, active optical MUX/Amp, passive cyclic AWG, and passive optical splitter (Channel) TP7 TP8 TP9 TP10

5 Super-PON Residential (1) OLT OLT TP1 TP2 TP3 TP4 TP5 TP6 Active Optical MUX/Amp Channel 1: Fiber Optic Cabling TP11 TP12 Channel 2: Fiber Optic Cabling Cyclic AWG Optical Splitter Passive Cyclic AWG Claudio DeSanti 5 Passive Optical Splitter Passive Optical Splitter Fiber optic cabling, passive cyclic AWG, and passive optical splitter (Channel) TP7 TP8 TP9 TP10

6 Super-PON Point to Point TP1 TP2 TP3 TP4 P2P TP11 TP12 Pt2Pt TP7 TP8 TP9 TP10 Pt2Pt Active Optical MUX/Amp TP5 TP6 Channel: Fiber Optic Cabling Optical MUX/Amp Cyclic AWG Passive Cyclic AWG P2P Fiber optic cabling, active optical MUX/Amp, and passive cyclic AWG (Channel) Claudio DeSanti 6

7 Super-PON Point to Point (1) TP1 TP2 TP3 TP4 P2P TP11 TP12 Pt2Pt TP7 TP8 TP9 TP10 Pt2Pt TP5 TP6 Active Optical MUX/Amp Channel 2: Fiber Optic Cabling Cyclic AWG Passive Cyclic AWG P2P Channel 1: Fiber Optic Cabling Fiber optic cabling and passive cyclic AWG (Channel) Claudio DeSanti 7

8 Agenda Refinements 2.5G-EPON Upstream Speed Considerations Claudio DeSanti 8

9 Speed Considerations (From Last Presentation) For residential support, an EML laser in the OLT and a DML laser in the allow: 10Gb/s downstream 2.5Gb/s upstream if the MUX/Amp does not contain dispersion compensation 25Gb/s downstream 10Gb/s upstream if the MUX/Amp does contain dispersion compensation For point-to-point support, EML lasers on both ends allow: 10Gb/s symmetric if the MUX/Amp does not contain dispersion compensation 25Gb/s symmetric if the MUX/Amp does contain dispersion compensation The 2.5Gb/s Ethernet speed is already defined for UTP cabling and is being defined for backplane operations IEEE 802.3bz and IEEE P802.3cb Defining it for optical operations seems a very doable effort Down clocking the 10Gb/s specification Enables to leverage for Ethernet the existing 2.5Gb/s GPON optical ecosystem Claudio DeSanti 9

10 2.5G Ethernet It is defined in IEEE 802.3bz as 2.5GBASE-T By downclocking 10GBASE-T and simplifying its PCS (FEC) XGMII now supports the 2.5Gb/s mode of operation: Change item a) in the list following the fourth paragraph of 46.1 to include 2.5 Gb/s and 5 Gb/s rates as follows: The XGMII has the following characteristics: a) It is capable of supporting at least one of the following rates of operation: 2.5 Gb/s, 5 Gb/s, or 10 Gb/s operation Summary of major concepts Insert item i) after the last item in the list under as follows: i) The XGMII is rate scalable and may support rates of 2.5 Gb/s, 5 Gb/s, and 10 Gb/s Application Change the second paragraph of as follows: This interface is used to provide media independence so that an identical media access controller may be used with all 2.5GBASE, 5GBASE, and 10GBASE PHY types. Claudio DeSanti 10

11 OSI REFERENCE MODEL LAYERS APPLICATION PRESENTATION SESSION TRANSPORT NETWORK MAC CLIENT OAM (Optional) ETHERNET LAYERS HIGHER LAYERS MULTIPOINT MAC CONTROL (MPCP) (Clause 77) MAC MEDIA ACCESS CONTROL RECONCILIATION (Clause 76) MAC CLIENT OAM (Optional) MAC MEDIA ACCESS CONTROL XGMII OLT TX_CLK: 1/64 f MAC ± 100ppm TX f MAC : 10Gb/s à MHz RX_CLK: 1/64 f MAC ± 100ppm RX f MAC : 2.5Gb/s à MHz 2.5G-EPON (upstream) DATA LINK PHYSICAL OSI REFERENCE MODEL LAYERS APPLICATION PRESENTATION SESSION TRANSPORT NETWORK DATA LINK PHYSICAL PHY PHY PCS (Clause 76) FEC (Clause 76) (Clause 76) PR-type (Clause 75) ETHERNET LAYERS HIGHER LAYERS MAC CLIENT OAM (Optional) MULTIPOINT MAC CONTROL (MPCP) (Clause 77) MAC - MEDIA ACCESS CONTROL RECONCILIATION (Clause 76) PCS (Clause 76) FEC (Clause 76) (Clause 76) XGMII PR-type (Clause 75) Claudio DeSanti Fiber 11 Fiber PON medium Optical distributor combiner(s) Fiber Fiber Allow XGMII to support different rates for RX and TX TX_CLK: 1/64 f MAC ± 100ppm TX f MAC : 2.5Gb/s à MHz RX_CLK: 1/64 f MAC ± 100ppm RX f MAC : 10Gb/s à MHz

12 2.5G-EPON FEC Considerations (1) 10G-EPON uses RS(255, 223) as FEC downstream and upstream ~13% overhead ~7.2 db coding gain ITU-T XG-PON (~10Gb/s downstream, ~2.5Gb/s upstream) uses: RS (248, 216) downstream (a truncated form of RS(255, 223)) RS (248, 232) upstream (a truncated form of RS(255, 239)) The RS(255, 239) code has: ~6.5% overhead ~5.9 db coding gain Does it make sense to use RS(255, 239) for 2.5G-EPON (upstream)? For Super-PON 10G downstream / 2.5G upstream asymmetric configuration Claudio DeSanti 12

13 TXD<0> First transfer TXD<31> TXD<0> Second transfer TXD<31> TXD<0> First transfer TXD<31> TXD<0> Second transfer TXD<31> XGMII Sync header XGMII Sync header 0 1 D0 2 9 D1 D2 D3 D4 D5 D6 D7 0 1 D0 2 9 D1 D2 D3 D4 D5 D6 D7 64B/66B Encoder Scrambler 64B/66B Encoder Scrambler Out of scrambler function S0 2 9 S1 S2 S3 S4 S5 S6 S7 Out of scrambler function S0 2 9 S1 S2 S3 S4 S5 S6 S7 1 S0 2 9 S1 S2 S3 S4 S5 S6 S7 1 S0 2 9 S1 S2 S3 S4 S5 S6 S padding B block 1 1 Aggregate 27 B Blocks B block B block G-EPON: RS(255,223) [~13% overhead] 2.5G-EPON: RS(255,239)??? [~6.5% overhead] 27 0 padding B block 1 1 Aggregate 29 B Blocks B block B block RS(255,223) encoder RS(255,239) encoder FEC codeword B block 1 1 B block B block B Parity 2 block 1 64B Parity 2 block 4 FEC codeword B block 1 1 B block B block B Parity 2 block 1 64B Parity 2 block 2 Transmit pattern 66B block B block 2 66B block 27 66B parity 1 2 block B parity block 4 Transmit pattern 66B block B block 2 66B block 29 66B parity 1 2 block B parity block 2 Gearbox Gearbox Claudio DeSanti tx_data-group<0> () tx_data-group<15> () tx_data-group<0> () tx_data-group<15> () 13

14 2.5G-EPON FEC Considerations (2) Changing the FEC means do a new implementation for 2.5G-EPON To get a 6.5% reduction in overhead Given the large availability of 10G-EPON implementations, it is better to stick to the 10G-EPON FEC Then 2.5G-EPON is just a downclock of 10G-EPON Plus maybe two bits for discovery Claudio DeSanti 14

15 802.3av Discovery Discovery Information Field in the REGISTER_REQ MPCPDU Discovery Information Field in the DISCOVERY GATE MPCPDU Claudio DeSanti 15

16 802.3ca Discovery Discovery Information Field in the REGISTER_REQ MPCPDU Discovery Information Field in the DISCOVERY GATE MPCPDU Claudio DeSanti 16

17 Possible 2.5G-EPON Discovery Discovery Information Field in the REGISTER_REQ MPCPDU Bit Flag field Values 0 is 1G upstream capable 0 transmitter is not capable of 1 Gb/s 1 transmitter is capable of 1 Gb/s 1 is 10G upstream capable 0 transmitter is not capable of 10 Gb/s 1 transmitter is capable of 10 Gb/s 2 is 25G upstream capable 0 transmitter is not capable of 25 Gb/s 1 transmitter is capable of 25 Gb/s 3 is 2.5G upstream capable 0 transmitter is not capable of 2.5 Gb/s 1 transmitter is capable of 2.5 Gb/s 4 1G registration attempt 0 transmitter is not capable of 1 Gb/s 1 transmitter is capable of 1 Gb/s 5 10G registration attempt 0 transmitter is not capable of 10 Gb/s 1 transmitter is capable of 10 Gb/s 6 25G registration attempt 0 transmitter is not capable of 25 Gb/s 1 transmitter is capable of 25 Gb/s 7 2.5G registration attempt 0 transmitter is not capable of 2.5 Gb/s 1 transmitter is capable of 2.5 Gb/s 8-15 Reserved Ignored on Reception Bit Flag field Values 0 OLT is 1G upstream capable 0 OLT does not support 1 Gb/s reception 1 OLT supports 1 Gb/s reception 1 OLT is 10G upstream capable 0 OLT does not support 10 Gb/s reception 1 OLT supports 10 Gb/s reception 2 OLT is 25G upstream capable 0 OLT does not support 25 Gb/s reception 1 OLT supports 25 Gb/s reception 0 OLT does not support 2.5 Gb/s reception Discovery Information Field in 3 OLT is 2.5G upstream capable 1 OLT supports 2.5 Gb/s reception the DISCOVERY GATE MPCPDU 0 OLT cannot receive 1 Gb/s data in this window 4 OLT is opening 1G discovery window 1 OLT can receive 1 Gb/s data in this window 5 OLT is opening 10G discovery window 0 OLT cannot receive 10 Gb/s data in this window 1 OLT can receive 10 Gb/s data in this window 6 OLT is opening 25G discovery window 0 OLT cannot receive 25 Gb/s data in this window 1 OLT can receive 25 Gb/s data in this window Claudio DeSanti 0 OLT cannot receive 2.5 Gb/s data in this window 7 OLT is opening 2.5G discovery window 1 OLT can receive 2.5 Gb/s data in this window Reserved Ignored on Reception

18 Summary 2.5G-EPON upstream appears to be very doable A downclock of 10G-EPON Allow XGMII to have different RX_CLK and TX_CLK Assign two bits in the REGISTER_REQ MPCPDU and in the DISCOVERY GATE MPCPDU for discovery Specify the optical parameters Probably a couple of pages in addition to the specification With the exception of the 2.5Gb/s speed, Super-PON would be a -only project Similar to 802.3bk Claudio DeSanti 18

19 Thank you Claudio DeSanti 19