ITU-T Rec. G.9903 (05/2021) Narrowband orthogonal frequency division multiplexing power line communication transceivers for G3-PLC networks
Amendment 1
Summary
History
1 Scope
2 References
3 Conventions and definitions
     3.1 Conventions
     3.2 Terms defined elsewhere
     3.3 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Introduction to OFDM and the power line channel
6 General description
     6.1 Overall infrastructure
     6.2 Coexistence with other PLC networks
          6.2.1 Frequency division coexistence mechanism
          6.2.2 Preamble-based coexistence mechanism (optional)
7 Physical layer specification
     7.1 Introduction
     7.2 System parameters
     7.3 Data rate, Reed-Solomon block size and maximum PSDU length
          7.3.1 Data rate calculation and RS block size
               7.3.1.1 CENELEC-A bandplan
               7.3.1.2 CENELEC-B bandplan
               7.3.1.3 FCC bandplan
          7.3.2 Maximum PSDU length calculation
     7.4 Frame structure
     7.5 Preamble
     7.6 Frame control header
          7.6.1 CENELEC bandplans
               7.6.1.1 FCH for a data frame
               7.6.1.2 FCH for ACK/NACK frame
               7.6.1.3 CRC5
          7.6.2 FCC bandplan
               7.6.2.1 FCH for a data frame
               7.6.2.2 FCH for ACK/NACK frame
               7.6.2.3 CRC8
     7.7 Payload of PHY frame
     7.8 Scrambler
     7.9 FEC coding
          7.9.1 Reed-Solomon encode r
          7.9.2 Convolutional encoder
               7.9.2.1 Encoding 2 Reed-Solomon blocks
          7.9.3 Robust and super robust modes
               7.9.3.1 Repetition coding by 4
               7.9.3.2 Repetition coding by 6
     7.10 Interleaver
          7.10.1 Elementary interleaver
          7.10.2 Full block interleaver
     7.11 Mapping for DBPSK/DQPSK/D8PSK
     7.12 Frequency domain pre-emphasis
     7.13 OFDM generation (IFFT and CP addition)
     7.14 Windowing
     7.15 Tone masking and tone mapping
          7.15.1 PN modulating unused subcarriers
     7.16 Coherent modulation scheme
          7.16.1 Frame structure – Coherent modulation scheme
          7.16.2 Preamble – Coherent modulation scheme
          7.16.3 Frame control header – Coherent modulation scheme
          7.16.4 CRC – Coherent modulation scheme
          7.16.5 Data scrambler – Coherent modulation scheme
          7.16.6 FEC coding – Coherent modulation scheme
          7.16.7 Payload padding – Coherent modulation scheme
          7.16.8 Interleaver – Coherent modulation scheme
          7.16.9 Coherent mapping for BPSK, QPSK, 8-PSK, 16-QAM and robust modes – Coherent modulation scheme
               7.16.9.1 Mapping for BPSK and robust mode – Coherent modulation scheme
               7.16.9.2 Mapping for QPSK modulation – Coherent modulation scheme
               7.16.9.3 Mapping for 8-PSK modulation – Coherent modulation scheme
               7.16.9.4 Mapping for 16-QAM modulation (applies only to FCC bandplan) – Coherent modulation scheme
          7.16.10 Pilot tones – Coherent modulation scheme
               7.16.10.1 Example of pilot tone assignment
          7.16.11 Frequency domain pre-emphasis – Coherent modulation scheme
          7.16.12 OFDM generation (IFFT and CP addition) – Coherent modulation scheme
          7.16.13 Windowing – Coherent modulation scheme
          7.16.14 Adaptive tone mapping and transmit power control – Coherent modulation scheme
     7.17 PHY primitives
          7.17.1 Data primitive
               7.17.1.1 PD-DATA.request
               7.17.1.2 PD-DATA.confirm
               7.17.1.3 PD-DATA.indication
               7.17.1.4 PD-ACK.request
               7.17.1.5 PD-ACK.confirm
               7.17.1.6 PD-ACK.indication
          7.17.2 Management primitives
               7.17.2.1 PLME_SET.request
               7.17.2.2 PLME_SET.confirm
               7.17.2.3 PLME_GET.request
               7.17.2.4 PLME_GET.confirm
               7.17.2.5 PLME_SET_TRX_STATE.request
               7.17.2.6 PLME_SET_TRX_STATE.confirm
               7.17.2.7 PLME_CS.request
               7.17.2.8 PLME_CS.confirm
8 Transmitter specifications
     8.1 Output level measurement
     8.2 Transmit spectrum mask
     8.3 Transmitter attenuation
     8.4 Spurious transmission
     8.5 System clock frequency tolerance
     8.6 Transmitter constellation
          8.6.1 Transmitter constellation error
          8.6.2 Transmit modulation accuracy test
          8.6.3 Error vector magnitude limits
     8.7 Transmitter spectral flatness
     8.8 Crossing MV/LV transformer
     8.9 MV coupler (informative)
     8.10 AC phase detection
9 Data link layer specifications
     9.1 Introduction
     9.2 Conventions
     9.3 MAC sublayer specification
          9.3.1 Channel access
               9.3.1.1 Overview
               9.3.1.2 Inter-frame (IFS) spacing
               9.3.1.3 CSMA-CA
               9.3.1.4 Priority
               9.3.1.5 ARQ
               9.3.1.6 Segmentation and reassembly overview
          9.3.2 MAC acknowledgement
               9.3.2.1 ACK Generation
               9.3.2.2 NACK Generation
               9.3.2.3 NACK Generation avoidance
               9.3.2.4 ACK and NACK validity
               9.3.2.5 Segment Retransmission
               9.3.2.6 Subsequent segment collision avoidance
          9.3.3 MAC sublayer service specification
               9.3.3.1 Selections
               9.3.3.2 Extensions
          9.3.4 MAC frame formats
               9.3.4.1 Selections
               9.3.4.2 Extensions
          9.3.5 MAC command frames
               9.3.5.1 Selections
               9.3.5.2 Extensions
                    9.3.5.2.1 MAC command frames supported
                    9.3.5.2.2 Tone map response
          9.3.6 MAC constants and PIB attributes
               9.3.6.1 Selections
               9.3.6.2 Extensions
                    9.3.6.2.1 Additional MAC sublayer constants
                    9.3.6.2.2 Additional MAC sublayer attributes
                    9.3.6.2.3 MAC sublayer attributes and their associated ID
          9.3.7 MAC functional description
               9.3.7.1 Selections
               9.3.7.2 Extensions
                    9.3.7.2.1 POS table
                    9.3.7.2.2 Neighbour Table
          9.3.8 MAC security suite specifications
          9.3.9 Message sequence chart illustrating MAC – PHY
               9.3.9.1 Selections
               9.3.9.2 Extensions
                    9.3.9.2.1 PAN start message sequence chart for PAN coordinators
                    9.3.9.2.2 Active scan message sequence chart
                    9.3.9.2.3 Data transmission message sequence chart
                    9.3.9.2.4 Channel estimation message sequence chart
          9.3.10 MAC annexes
          9.3.11 Modified MAC sublayer data primitives
               9.3.11.1 MCPS-DATA.request
               9.3.11.2 MCPS-DATA.indication
     9.4 IPv6 adaptation sublayer specifications
          9.4.1 Information base attributes
               9.4.1.1 General
               9.4.1.2 Routing, broadcast and blacklisted neighbour table description
          9.4.2 Data frame format, datagram transmission and addressing
               9.4.2.1 Selections from [IETF RFC 4944]
               9.4.2.2 Selections from [IETF RFC 6282]
               9.4.2.3  Extensions
                    9.4.2.3.1 Command frame header
                    9.4.2.3.2 Security processing for adaptation layer frames
          9.4.3 Mesh routing
               9.4.3.1 Selections from Annex D
               9.4.3.2 Extensions to Annex D
                    9.4.3.2.1 Unicast packet routing
                    9.4.3.2.2 Multicast/broadcast
                         9.4.3.2.2.1 Packet routing
                         9.4.3.2.2.2 Groups
                    9.4.3.2.3 Route discovery
                         9.4.3.2.3.1 Manual route discovery
                         9.4.3.2.3.2 Automatic route discovery
                         9.4.3.2.3.3 Route Request generation frequency limit
                    9.4.3.2.4 Path discovery
                         9.4.3.2.4.1 Operation
                    9.4.3.2.5 Route repair and route error
                    9.4.3.2.6 Link cost computation
                    9.4.3.2.7 Routing packet and message formats
                         9.4.3.2.7.1 General packet format
                         9.4.3.2.7.2 Route request (RREQ) and route reply (RREP) message format
                         9.4.3.2.7.3 Route error (RERR) message format
                         9.4.3.2.7.4 Path request (PREQ) message format
                         9.4.3.2.7.5 Path reply (PREP) message format
                         9.4.3.2.7.6 RLCREQ message format
                         9.4.3.2.7.7 RLCREP message format
          9.4.4 Commissioning of new devices
               9.4.4.1 Selections from Annex E
               9.4.4.2 Extensions to Annex E
                    9.4.4.2.1 LoWPAN bootstrapping protocol (LBP) message format
                         9.4.4.2.1.1 General
                         9.4.4.2.1.2 Embedded EAP messages
                         9.4.4.2.1.3 Configuration parameters
                    9.4.4.2.2 6LoWPAN bootstrapping procedures
                         9.4.4.2.2.1 Overview
                         9.4.4.2.2.2 Discovering phase
                         9.4.4.2.2.3 Access control phase
                         9.4.4.2.2.4 Authentication and key distribution phase
                         9.4.4.2.2.5 Authorization and initial configuration phase
                         9.4.4.2.2.6 Joining a PAN for any node except coordinator
                         9.4.4.2.2.7 Leaving a PAN – Removal of a device by the PAN coordinator
                         9.4.4.2.2.8 Leaving a PAN – Removal of a device by itself
          9.4.5 Sniffer mode (optional mode)
          9.4.6 Adaptation sublayer service primitives
               9.4.6.1 ADP data primitives
                    9.4.6.1.1 Overview
                    9.4.6.1.2 ADPD-DATA.request
                         9.4.6.1.2.1 Semantics of the service primitive
                         9.4.6.1.2.2 When generated
                         9.4.6.1.2.3 Effect on receipt
                    9.4.6.1.3 ADPD-DATA.confirm
                         9.4.6.1.3.1 Semantics of the service primitive
                         9.4.6.1.3.2 When generated
                         9.4.6.1.3.3 Effect on receipt
                    9.4.6.1.4 ADPD-DATA.indication
                         9.4.6.1.4.1 Semantics of the service primitive
                         9.4.6.1.4.2 When generated
                         9.4.6.1.4.3 Effect on receipt
               9.4.6.2 ADP management service
                    9.4.6.2.1 Overview
                    9.4.6.2.2 ADPM-DISCOVERY.request
                         9.4.6.2.2.1 Semantics of the service primitive
                         9.4.6.2.2.2 When generated
                         9.4.6.2.2.3 Effect on receipt
                    9.4.6.2.3 ADPM-DISCOVERY.confirm
                         9.4.6.2.3.1 Semantics of the service primitive
                         9.4.6.2.3.2 When generated
                         9.4.6.2.3.3 Effect on receipt
                    9.4.6.2.4 ADPM-NETWORK-START.request
                         9.4.6.2.4.1 Semantics of the service primitive
                         9.4.6.2.4.2 When generated
                         9.4.6.2.4.3 Effect on receipt
                    9.4.6.2.5 ADPM-NETWORK-START.confirm
                         9.4.6.2.5.1 Semantics of the service primitive
                         9.4.6.2.5.2 When generated
                         9.4.6.2.5.3 Effect on receipt
                    9.4.6.2.6 ADPM-NETWORK-JOIN.request
                         9.4.6.2.6.1 Semantics of the service primitive
                         9.4.6.2.6.2 When generated
                         9.4.6.2.6.3 Effect on receipt
                    9.4.6.2.7 ADPM-NETWORK-JOIN.confirm
                         9.4.6.2.7.1 Semantics of the service primitive
                         9.4.6.2.7.2 When generated
                         9.4.6.2.7.3 Effect on receipt
                    9.4.6.2.8 ADPM-NETWORK-LEAVE.request
                         9.4.6.2.8.1 Semantics of the service primitive
                         9.4.6.2.8.2 When generated
                         9.4.6.2.8.3 Effect on receipt
                    9.4.6.2.9 ADPM-NETWORK-LEAVE.indication
                         9.4.6.2.9.1 Semantics of the service primitive
                         9.4.6.2.9.2 When generated
                         9.4.6.2.9.3 Effect on receipt
                    9.4.6.2.10 ADPM-NETWORK-LEAVE.confirm
                         9.4.6.2.10.1 Semantics of the service primitive
                         9.4.6.2.10.2 When generated
                         9.4.6.2.10.3 Effect on receipt
                    9.4.6.2.11 ADPM-RESET.request
                         9.4.6.2.11.1 Semantics of the service primitive
                         9.4.6.2.11.2 When generated
                         9.4.6.2.11.3 Effect on receipt
                    9.4.6.2.12 ADPM-RESET.confirm
                         9.4.6.2.12.1 Semantics of the service primitive
                         9.4.6.2.12.2 When generated
                         9.4.6.2.12.3 Effect on receipt
                    9.4.6.2.13 ADPM-GET.request
                         9.4.6.2.13.1 Semantics of the service primitive
                         9.4.6.2.13.2 When generated
                         9.4.6.2.13.3 Effect on receipt
                    9.4.6.2.14 ADPM-GET.confirm
                         9.4.6.2.14.1 Semantics of the service primitive
                         9.4.6.2.14.2 When generated
                         9.4.6.2.14.3 Effect on receipt
                    9.4.6.2.15 ADPM-SET.request
                         9.4.6.2.15.1 Semantics of the service primitive
                         9.4.6.2.15.2 When generated
                         9.4.6.2.15.3 Effect on receipt
                    9.4.6.2.16 ADPM-SET.confirm
                         9.4.6.2.16.1 Semantics of the service primitive
                         9.4.6.2.16.2 When generated
                         9.4.6.2.16.3 Effect on receipt
                    9.4.6.2.17 ADPM-NETWORK-STATUS.indication
                         9.4.6.2.17.1 Semantics of the service primitive
                         9.4.6.2.17.2 When generated
                         9.4.6.2.17.3 Effect on receipt
                    9.4.6.2.18 ADPM-ROUTE-DISCOVERY.request
                         9.4.6.2.18.1 Semantics of the service primitive
                         9.4.6.2.18.2 When generated
                         9.4.6.2.18.3 Effect on receipt
                    9.4.6.2.19 ADPM-ROUTE-DISCOVERY.confirm
                         9.4.6.2.19.1 Semantics of the service primitive
                         9.4.6.2.19.2 When generated
                         9.4.6.2.19.3 Effect on receipt
                    9.4.6.2.20 ADPM-PATH-DISCOVERY.request
                         9.4.6.2.20.1 Semantics of the service primitive
                         9.4.6.2.20.2 When generated
                         9.4.6.2.20.3 Effect on receipt
                    9.4.6.2.21 ADPM-PATH-DISCOVERY.confirm
                         9.4.6.2.21.1 Semantics of the service primitive
                         9.4.6.2.21.2 When generated
                         9.4.6.2.21.3 Effect on receipt
                    9.4.6.2.22 ADPM-LBP.request
                         9.4.6.2.22.1 Semantics of the service primitive
                         9.4.6.2.22.2 When generated
                         9.4.6.2.22.3 Effect on receipt
                    9.4.6.2.23 ADPM-LBP.confirm
                         9.4.6.2.23.1 Semantics of the service primitive
                         9.4.6.2.23.2 When generated
                         9.4.6.2.23.3 Effect on receipt
                    9.4.6.2.24 ADPM-LBP.indication
                         9.4.6.2.24.1 Semantics of the service primitive
                         9.4.6.2.24.2 When generated
                         9.4.6.2.24.3 Effect on receipt
                    9.4.6.2.25 ADPM-BUFFER.indication
                         9.4.6.2.25.1 Semantics of the service primitive
                         9.4.6.2.25.2 When generated
                         9.4.6.2.25.3 Effect on receipt
               9.4.6.3 Behaviour to MAC indications
                    9.4.6.3.1 Overview
                    9.4.6.3.2 MCPS-DATA.indication
                    9.4.6.3.3 MLME-ASSOCIATE.indication
                    9.4.6.3.4 MLME-DISASSOCIATE.indication
                    9.4.6.3.5 MLME-BEACON-NOTIFY.indication
                    9.4.6.3.6 MLME-GTS.indication
                    9.4.6.3.7 MLME-ORPHAN.indication
                    9.4.6.3.8 MLME-COMM-STATUS.indication
     9.5 Functional description
          9.5.1 Network formation
10 Security
     10.1 Access control and authentication
     10.2 Confidentiality and integrity
     10.3 Anti-replay and DoS prevention
     10.4 Authentication and key distribution protocol – Selections from [IETF RFC 3748]
     10.5 EAP method
          10.5.1 Overview of the EAP-PSK
          10.5.2 Group key distribution
          10.5.3 Configuration extension format
          10.5.4 Peer side procedure
          10.5.5 Server side procedure
Annex A  Protocol implementation conformance statement
     A.1 Overview
     A.2 PICS proforma tables
          A.2.1 Functional device types (from clause D.7.1 of [IEEE 802.15.4])
          A.2.2 PHY functions (from clause D.7.2.1 of [IEEE 802.15.4])
          A.2.3 PHY packet (from clause D.7.2.2 of [IEEE 802.15.4])
          A.2.4 Radio frequency (from clause D.7.2.3 of [IEEE 802.15.4])
          A.2.5 MAC sublayer functions (from clause D.7.3.1 of [IEEE 802.15.4])
          A.2.6 MAC frames (from clause D.7.3.2 of [IEEE 802.15.4])
Annex B  Routing cost
     B.1 Composite metric method
Annex C  Device starting sequence of messages
Annex D  The lightweight on-demand Ad hoc distance-vector  routing protocol – next generation (LOADng)
     D.1 Introduction
     D.2 Terminology and notation
          D.2.1 Message and message field notation
          D.2.2 Variable notation
          D.2.3 Other notation
          D.2.4 Terminology
     D.3 Applicability statement
     D.4 Protocol overview and functioning
          D.4.1 Overview
          D.4.2 LOADng routers and LOADng interfaces
          D.4.3 Information base overview
          D.4.4 Signalling overview
     D.5 Protocol parameters
          D.5.1 Protocol and port numbers
          D.5.2 Router parameters
          D.5.3 Interface parameters
          D.5.4 Constants
     D.6 Protocol message content
          D.6.1 Route request (RREQ) messages
          D.6.2 Route reply (RREP) messages
          D.6.3 Route reply acknowledgement (RREP_ACK) messages
          D.6.4 Route error (RERR) messages
     D.7 Information base
          D.7.1 Routing set
          D.7.2 Local interface set
          D.7.3 Blacklisted neighbour set
          D.7.4 Destination address set
          D.7.5 Pending acknowledgment set
     D.8 LOADng router sequence numbers
     D.9 Route maintenance
     D.10 Unidirectional link handling
          D.10.1 Blacklist usage
     D.11 Common rules for RREQ and RREP messages
          D.11.1 Identifying invalid RREQ or RREP messages
          D.11.2 RREQ and RREP message processing
     D.12 Route requests (RREQs)
          D.12.1 RREQ generation
          D.12.2 RREQ processing
          D.12.3 RREQ forwarding
          D.12.4 RREQ transmission
     D.13 Route replies (RREPs)
          D.13.1 RREP generation
          D.13.2 RREP processing
          D.13.3 RREP forwarding
          D.13.4 RREP transmission
     D.14 Route errors (RERRs)
          D.14.1 Identifying invalid RERR messages
          D.14.2 RERR generation
          D.14.3 RERR processing
          D.14.4 RERR forwarding
          D.14.5 RERR transmission
     D.15 Route reply acknowledgments (RREP_ACKs)
          D.15.1 Identifying invalid RREP_ACK messages
          D.15.2 RREP_ACK generation
          D.15.3 RREP_ACK processing
          D.15.4 RREP_ACK forwarding
          D.15.5 RREP_ACK transmission
     D.16 Metrics
          D.16.1 Specifying new metrics
     D.17 Security considerations
          D.17.1 Confidentiality
          D.17.2 Integrity
          D.17.3 Channel jamming and state explosion
          D.17.4 Interaction with external routing domains
Annex E  Commissioning in 6LoWPAN
     E.1 Introduction
     E.2 Terminology
          E.2.1 Requirements notation
     E.3 Bootstrapping
          E.3.1 Resetting the device
          E.3.2 Scanning through channels
          E.3.3 LoWPAN bootstrapping mechanism
               E.3.3.1 LoWPAN bootstrapping protocol message format
                    E.3.3.1.1 LBP message
               E.3.3.2 LoWPAN bootstrapping information base
               E.3.3.3 LBA discovering phase
               E.3.3.4 LoWPAN bootstrapping protocol (LBP)
               E.3.3.5 LBP in secured 6LoWPAN
               E.3.3.6 Role of entities in LBP
          E.3.4 Assigning the short address
          E.3.5 Obtaining IPv6 address
          E.3.6 Configuration parameters
     E.4 IANA consideration
     E.5 Security considerations
Annex F  Regional requirements for Japan
     F.1 Overview
     F.2 Physical layer specifications for ARIB bandplan
          F.2.1 System fundamental parameters for ARIB bandplan
     F.3 Data link layer specifications
          F.3.1 TM (tone map)
          F.3.2 CIFS
          F.3.3 LBP joining procedure
Annex G   Regional requirements for the USA
Annex H  G3-PLC Hybrid PLC & RF Profile
     H.1 Scope
     H.2 Conventions and definitions
          H.2.1 Conventions
          H.2.2 Definitions
     H.3 Abbreviations and acronyms
     H.4 General description
     H.5 RF physical layer
     H.6 RF MAC sublayer
          H.6.1 Functional description
          H.6.2 Frame formats
          H.6.3 Service specification
          H.6.4 Security specification
          H.6.5 Functional extensions
               H.6.5.1 Information Element definition
                    H.6.5.1.1 Reverse Link Quality IE (RLQ-IE)
                    H.6.5.1.2 Link Information IE (LI-IE)
               H.6.5.2  Additional MAC sublayer attributes
                    H.6.5.2.1  RF POS table
     H.7 Hybrid abstraction layer
          H.7.1 Media Type definition
          H.7.2 Hybrid abstraction layer primitives
               H.7.2.1  HyAL-DATA.request
                    H.7.2.1.1  Semantics of the service primitive
                    H.7.2.1.2  Service description
               H.7.2.2  HyAL-DATA.confirm
                    H.7.2.2.1  Semantics of the service primitive
                    H.7.2.2.2  Service description
               H.7.2.3  HyAL-DATA.indication
                    H.7.2.3.1  Semantics of the service primitive
                    H.7.2.3.2  Service description
               H.7.2.4  HyAL-SCAN.request
                    H.7.2.4.1  Semantics of the service primitive
                    H.7.2.4.2  Service description
               H.7.2.5  HyAL-SCAN.confirm
                    H.7.2.5.1  Semantics of the service primitive
                    H.7.2.5.2  Service description
               H.7.2.6  HyAL-BEACON-NOTIFY.indication
                    H.7.2.6.1  Semantics of the service primitive
                    H.7.2.6.2  Service description
               H.7.2.7  HyAL-COMM-STATUS.indication
                    H.7.2.7.1  Semantics of the service primitive
                    H.7.2.7.2  Service description
               H.7.2.8  HyAL-START.request
                    H.7.2.8.1  Semantics of the service primitive
                    H.7.2.8.2  Service description
               H.7.2.9  HyAL-START.confirm
                    H.7.2.9.1  Semantics of the service primitive
                    H.7.2.9.2  Service description
               H.7.2.10  HyAL-RESET.request
                    H.7.2.10.1  Semantics of the service primitive
                    H.7.2.10.2  Service description
               H.7.2.11  HyAL-RESET.confirm
                    H.7.2.11.1  Semantics of the service primitive
                    H.7.2.11.2  Service description
          H.7.3 Second transmission attempt using backup medium
     H.8 IPv6 adaptation sublayer
          H.8.1 IPv6 adaptation sublayer specification
          H.8.2 Route cost computation: extension to the composite metric
               H.8.2.1 PLC link cost
               H.8.2.2 RF link cost
          H.8.3 Disabling backup medium
Appendix I  Examples on encoding and decoding
     I.1 Example for data encoding
     I.2 Example for data decoding
Appendix II  Test vectors for cryptographic building blocks
     II.1 Introduction
          II.1.1 Short frame ciphering
          II.1.2 Long frame ciphering
Appendix III  Test vectors for cryptographic building blocks specific to the G3-PLC Hybrid PLC & RF Profile
     III.1 Introduction
     III.2  Data frame and Enh-ACK ciphering
          III.2.1  Data frame
          III.2.2  Enh-ACK
Bibliography