HomePlug AV PHY

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HomePlug AV PHY

• (c) 2013 R. Newman
• University of Florida

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What is HomePlug AV?

• Broadband PLC for home networking
• Open industry standard
• 6 manufacturers (including Intellon)
• Developed 2003-2007 by Homeplug Powerline
  Alliance (HPA)
• Consortium of chip designers, OEMs, PLC users
• Products shipped in 2006
• Second ethernet class PLC, most widely available
• 150 Mbps coded PHY data rate
• 0ver 40 million units shipped
• Comprises
• PHY modulation, coupling, FEC, etc.
• MAC medium access, ARQ, etc.
• Bridging to other PLC networks or to
  803.3/11/etc.

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Reference Model
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Protocol Layer Architecture
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HPAV Networks

• Physical Network (PhyNet)
• Relative to a station (STA)
• All other STAs able to communicate with the
  reference STA
• Logical Network (AVLN)
• Has a Central Coordinator (CCo) STA
• Set of STAs with same
• Network ID (NID) and
• Network Membership Key (NMK) (usually)

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AV Logical Networks

• Neighbor networks
• Hidden nodes

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HPAV STA Roles

• STA Level-0 CCo (no QoS support)
• Assoc/Authenticate new STA
• TEI provisioning
• CSMA operation
• Neighbor Network (NNW) passive coordination
• Level-1 CCo Level-0 plus
• TDMA operation/scheduling/admission control
• GLID provisioning
• Uncoordinated mode with NNWs
• Level-2 CCo Level-1 plus
• Coordinated mode with NNWs

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HPAV PHY

• Windowed OFDM 917 carriers 1.8 30 MHz
• 40.96us symbol time, 4.96us rolloff
• Variable Cyclic Prefix
• Turbo Convolution Codes, copy codes
• Robust Frame Control (-5 dB)
• Robo Modes (5 10 Mbps)
• Bit Loaded Payload
• Tone Maps synchronized with AC line cycle
• coherent modulation up to 1024-QAM
• 200 Mbps channel rate/150 Mbps information rate

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HPAV Transceiver
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HPAV Transmitter

• Data paths for HP1.0.1 FC, AV FC, and payload
• Turbo convolutional encoders for AV paths
• Architecture similar to HP 1.0.1 transmitter

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HPAV Receiver

• 384 point FFT for HP1.0.1 FC
• 3072 point FFT for AV FC and payload
• Turbo convolutional decoders for AV paths

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HPAV OFDM

• 1155 evenly spaced carriers 1.80-30.00 Mhz
• 917 carriers used for modulation
• notch amateur/government bands
• 24.414 kHz carrier spacing
• 40.96 usec raw symbol duration
• Cyclic Prefix (CP) has three lengths
• Set by tone map during channel adaptation
• 4.96 usec roll-off interval variable Guard
  Interval
• 18.32 usec GI for Frame Control
• 5.56 usec GI for Robo, HS-Robo
• 7.56 usec GI for mini-Robo
• 47.12, 7.56, and 5.56 usec GI for negotiated TMs

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HPAV OFDM

• Modulation
• Coherent modulation used
• BPSK, QPSK, 8-QAM, 16-QAM, 64-QAM, 256-QAM,
  1024-QAM (1,2,4,6,8,10 bits/carrier)
• Negotiated TMs
• Carriers bit-loaded
• Robust Modulation Modes
• QPSK all unmasked carriers, rate ½ turbo code
• GI and interleaving redundancy differs (4, 2, 5
  copies)
• Robo 5 Mbps, 520 octet PHY Block (PB520)
• High-speed Robo 10 Mbps, PB520
• mini-Robo 4 Mbps, 136 octet PB (PB136)

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HPAV PHY Frames

• 4 PPDU Formats
• AV-Only Short PPDU
• Only HPAV preamble and Frame Control (FC)
• AV-Only Long PPDU
• Like above, but with (data) payload
• Hybrid Short PPDU
• Hybrid preamble, HP1.0 FC and HPAV FC
• Hybrid Long PPDU
• Like above, but with (data) payload

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HPAV PHY Payload

• Forward Error Correction (FEC) blocks
• 520 octet or 136 octet length
• 4 Modulation Types
• Fixed ROBO, High-speed ROBO, Mini-Robo
• Negotiated Tone Maps (channel capacity)
• 5 PHY Payload Formats
• Mini-ROBO one 136-octet FEC Block
• ROBO one 520-octet FEC Block
• High-Speed ROBO 1-3 520-octet FEC Blocks
• Negotiated TM one 136-octet FEC Block
• Negotiated TM gt 1 520-octet FEC Blocks

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AV Mode Long PPDU

• AV-Only Delimiter
• Preamble of 7.5 SYNCP and 2.5 SYNCM symbols
• HPAV FC may have 2 symbols
• Second FC symbol used when many carriers masked
• Cyclic prefix fixed on first 2 payload symbols
• CP assigned by TM after that

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HPAV Hybrid Long PPDU

• Hybrid Delimiter
• Preamble of 7.5 SYNCP and 1.5 SYNCM symbols
• HPAV FC may have 2 symbols
• Cyclic prefix fixed on first 2 payload symbols
• CP assigned by tone map after that

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HPAV Symbol

• 75 MHz Clock
• 3072-point IFFT (40.96 usec)
• Roll-off Interval (RI) 372 samples (4.96
  usec)
• Guard Interval (GI) variable
• 1374 samples for FC (18.32 usec)
• 417, 567, or 3534 samples for data
• 417 for Robo HS-Robo, 567 for mini-Robo

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HPAV Special Symbols

• Detection of these used for Physical Carrier
  Sense (PCS)
• SYNCP and SYNCM symbols
• Used only in preamble
• Omit CP (raw symbols only repeated)
• SYNCM is SYNCP inverted
• Priority Resolution Signal
• Derived from HP 1.0.1 PRS
• Add HPAV carriers
• Reverse sign of phases used in preamble

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Frame Control FEC Encoder

• Rate ½ turbo convolutional encoder
• Interleaver
• Diversity copier
• QPSK on all unmasked carriers
• Q-channel offset by 128 from I-channel
• A second symbol (if needed) starts with bit
  address offset by 64 from first symbol

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Payload FEC Encoder

• Turbo convolutional encoder
• Two rate 2/3 recursive systematic convolutional
  (RSC) constituent codes
• Both have 8 states
• Support 520, 136, 16 octet blocks
• Rate ½ or 16/21 after puncturing

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HPAV NA Transmit Spectrum Mask
Band used by HomePlug AV
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HPAV Spectral Occupancy
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HPAV Carrier Spectral Occupancy
Band used by HomePlug 1.0