DOCSIS 3.1 Mind Map ‘probing’ -also for time and power adjustment -3 types Single Symbol/skipped/staggered -> single coef pre-equalization adapt to available spectrum variable bit loading or Upstream profile testing ‘Probe Frames’ Profiles A, B, C, D , … OUDP Testing SID TLV 46.12 MMM.MAP - Ethernet Frames in TCC (REG / DBC) CM TX 65 dBmV/channel ‘profile promotion’ via RCC in REG / DBC Profile A (default) ID = 0 MSS 65dBmV/#subcarriers O-INIT-RNG-REQ = condensed B-INIT-RNG-REQ = “initial ranging signal” - symbol pair structure PIE AQM ID = 255 qpsk/qam16/qam64 Channel Bonding DOWNSTREAM 258 MHz + 5x192 MHz 1.218 GHz + 3x192 MHz 1.794 GHz MMM.ODS-REQ/RSP Active OUDP IUC (OFDMA Upstream Data Profile) = an IUC via TLV 46.11 HQoS Max 2 per CM IUC13 (default) OFDMA duty-cycle DLS - DS: 24x SC-QAM DVB-C + 2x OFDM - US: 8x A-TDMA/S-CDMA + 2x OFDMA MMM.OPT-REQ/RSP/ACK ”fine ranging signal” 3.1 UPSTREAM DTP NCP Solve MAC <-> PHY per OFDM symbol IEEE-1588-2008, (GPS, DTI…) Level I, II,III,IV,V system Extended Timestamp 64 bit TS-MB Type5 OFDMA Channel - Type5 MAP 5 MHz ...204 MHz 42..65..85..117 Hello World! - OFDM Downstream Spectrum request - MER per subcarrier reporting - In 6MHz contigious spectrum - surrounded by #8 continuous pilots Version 5 MAP Mixed constellation 1.5 dB granularity Downstream profile testing Usability, codeword count, statistics symbols in probe frames patterns P-IE MMM.P-MAP subcarriers in/excluded UCD change bitmask OC,TC, BC,GC Timestamp - ‘SYNC MMM’ PLC “Help CM come online” - Transport of MMM in MC - DPD, OCD - Timestamps - Energy Management signaling - 8 or 16 subcarriers (50/25 kHz) = 400 kHz ~ 1 Mbps capacity - on 1 MHz grid with lowest subcarrier - BPSK preamble pattern (8 OFDM symbols) followed QAM16 data (120 symbols) repeated every 128 OFDM symbols TR-MB - EM-MB - MMM.DPD OFDM Downstream Profile Descriptor - Per OFDM channel profiles are unique! PDP A, PDP B, .. PDP.NCP - DPD links QAM order to subcarrier - MMM.OCD Downstream exclusion band rules - minimum 22 MHz TWTT 204,8 MHz -OFDM Channel Descriptor -Cyclic Prefix -RP time windowing Downstream OFDM -Subcarrier x[0]frequency - 50/25 kHz subcarrier spacing (#4096 or #8192) -Location of pilots, - 20us/40us symbol duration data, PLC ,excluded - Bandwidth 24 – 192 MHz per channel subcarriers QAM 64 - 4096 - 6dB pilot boosting LDPC OFDM symbol capture Sleep while you can MMM.DTP-REQ/RSP/ACK Cyclic Prefix (max 5us) & Roll-Off Prefix (24MHz with guard bands) - 1MHz + nx25/50kHz gaps - 2MHz contigious - Robert Gallager 1960 - 3-6dB gain over RS-FEC BCH+LDPC (data) LDPC (PLC) DVB-C2 based only 8/9 (16000 bit LDPC) - Upstream OFDMA MMM.UCD type51/version5 cm-tadj TRO K: symbols per minislot 6 to 36 6.4 MHz/10 MHz – 96 MHz bandwidth per channel - 50/25 kHz subcarrier spacing (#1920/#3840) - 20us/40us symbol duration - CM: BPSK – 4096-QAM CMTS: BPSK – 1024-QAM (2048/4096 should) - Cyclic Prefic configurable 0.9 .. 6.5us - LDPC coding rate configurable edge vs. body - windowing RRC -Window roloff RP - Cyclic Prefix (max 6.25 us) RP vs. CP optimization (CP > RP) Q: subcarriers per minislot 8 or 16 - QAM1024 @ 33 dB SNR QAM4096 40 dB SNR ? True Ranging Offset Pilot pattern FEC codeword selection - Long 8/9 89% - Medium 28/33 85% - Short ¾ 75% - 1-7 for Q 8 - 8-15 for Q 16 minislots QxK sub-minislots QD-BW-REQ Pilot boost 4.7dB - 5-7 for Q 8 - 12-14 for Q 16 Copyright© 2014 www.Excentis.com/training -
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