Network Working GroupOPSAWG                                                           Y. Chen
Internet-Draft                                                    D. Liu
Updates: 5416 (if approved)                                      H. Deng
Intended status: Standards Track                                 H. Deng
Expires: November Apr, 2014                            China Mobile
Expires: August 18, 2014                                        Lei. Zhu
                                                                  Huawei
                                                                Oct 2013
                                                       February 14, 2014

    CAPWAP Extension for 802.11n and Power/channel Reconfiguration
                 draft-ietf-opsawg-capwap-extension-01 Autoconfiguration
                 draft-ietf-opsawg-capwap-extension-02

Abstract

   CAPWAP binding for 802.11 is specified by RFC5416 and it was based on
   IEEE 802-11.2007 standard.  After RFC5416 was published in 2009,
   there was were several new amendment amendments of 802.11 has have been published.
   802.11n is one of those amendment amendments and it has been widely used in
   real deployment.  This document extends the CAPWAP binding for 802.11
   to support 802.11n and also defines a power and channel auto
   configuration extension.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on August 18, 2014.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   2   3
   3.  CAPWAP 802.11n support  Abbreviations . . . . . . . . . . . . . . . . . . .   2 . . . . .   3
   4.  CAPWAP extension for 802.11n support Support  . . . . . . . . . . . . . . . . . . .   3
     4.1.  CAPWAP Extension for 802.11n Support  . . . . . . . . . .   4
       4.1.1.  802.11n Radio Capability Message Element Information  . . . . . . . .   3
     4.2.   4
       4.1.2.  802.11n Radio Configuration Message Element . . . . . . .   4
     4.3.
       4.1.3.  802.11n Station Information . . . . . . . . . . . . . . .   5   6
   5.  Power and Channel auto reconfiguration Autoconfiguration . . . . . . . . . . .   6 . .   7
     5.1.  Channel Autoconfiguration When WTP Power On . . . . . . .   7
     5.2.  Power Configuration When WTP Power On . . . . . . . . . .   8
     5.3.  Channel/Power Auto Adjusment  . . . . . . . . . . . . . .   8
       5.3.1.  Scan Parameter Message Element  . . . . . . . . . . . . .   7
     5.2.   9
       5.3.2.  Channel Bind Message Element  . . . . . . . . . . . . . .   8
     5.3.  10
       5.3.3.  Channel Scan Report . . . . . . . . . . . . . . . . . . .   9
     5.4.  11
       5.3.4.  Neighbor WTP Report . . . . . . . . . . . . . . . . . . .  11  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12  13
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12  13
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  12  14
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13  14
   10. Normative References  . . . . . . . . . . . . . . . . . . . .  13  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13  15

1.  Introduction

   IEEE 802.11n standard was published in 2009 and it is an amendment to
   the IEEE 802.11-2007 standard to improve network throughput. standard.  The maximum data rate increases to 600Mbit/s physical throughput rate.
   600Mbps.  In the physical layer, 802.11n use OFDM and MIMO to achieve
   the high throughput. 802.11n also use multiple antennas to form
   antenna array which can be dynamically adjusted to improve the signal
   strength and extend the coverage.

   There are couple of several capabilities of 802.11n need to be supported by
   CAPWAP control message message, such as radio capability, radio configuration
   and station information. information etc.  This document specifies the 802.11n and
   power/channel auto-configuration extensions for CAPWAP.

   For the AC/WTP that does not support the extensions defined by this
   document, it can simply ignore the extensions and will not cause any
   incompatible issue.

2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

3.  Abbreviations

      AC: Access Controller
      A-MSDU:Aggregate MAC Service Data Unit
      A-MPDU:Aggregate MAC Protocol Data Unit
      MIMO: Multi-input Multi-output
      MSDU: MAC Service Data Unit
      MPDU: MAC Protocol Data Unit
      MCS: Maximum Modulation and Coding Scheme
      OFDM: Orthogonal Frequency-Division Multiplexing
      WTP: Wireless Termination Points.

4.  CAPWAP 802.11n support Support

   [IEEE-802.11.2009] standard was published in 2009 and it is an
   amendment of the IEEE 802.11-2007 standard to improve throughput.
   The maximum data rate increases to 600Mbit/s physical throughput
   rate. 600Mbps.  In the physical layer,
   802.11n use OFDM and MIMO to achieve
   the high throughput. 802.11n use
   multiple antennas to form antenna array which can be dynamically
   adjusted to improve the signal strength and extend the coverage.

   802.11n support three modes of channel usage: 20MHz mode, 40MHz mode
   and mixed mode.802.11n mode. 802.11n has a new feature called channel binding.  It
   can bind two adjacent 20MHz channel to one 40MHz channel to improve
   the throughput.If using 40MHz channel configuration there will be
   only one non-overlapping channel in 2.4GHz.  In the large scale
   deployment scenario, operator need to use 20MHz channel configuration
   in 2.4GHz to allow more non-overlapping channels.

   In MAC layer, a new feature of 802.11n is Short Guard Interval(GI).
   802.11a/g use uses 800ns guard interval between the adjacent information
   symbols.  In 802.11n, the GI can be configured to 400nm under good
   wireless condition.

   Another feature in 802.11 MAC layer is Block ACK. 802.11n can use one
   ACK frame to acknowledge several MPDU receiving event.

   CAPWAP need needs to be extended to support the above new 802.11n
   features.  For example, CAPWAP should allow the access controller to
   know the supported 802.11n features of WTP and the access controller
   should be able to configure the different channel binding modes.  This document
   defines extension of the CAPWAP 802.11 binding to support 802.11n
   features.

4. modes for
   WTP.

4.1.  CAPWAP extension Extension for 802.11n support Support

   There are three 802.11n features need to be supported by CAPWAP
   802.11 binding: 802.11n radio capability, 802.11n radio configuration
   and station information.  This section defines the extension of
   current CAPWAP 802.11 binding to support 802.11n features.

4.1.

4.1.1.  802.11n Radio Capability Message Element Information

   [RFC5416] defines IEEE 802.11 binding for CAPWAP protocol.  It
   defines IEEE 802.11 Information Element (Type 1029) which is used to
   communicate any IE defined in IEEE 802.11 protocol.  This document defines
   802.11n radio capability information element which is composed  The detail
   definition of the IEEE 802.11 Information Element header that defined is in section 6.6 of
   [RFC5416] and the
   [RFC5416].  The IEEE 802.11 HT information element that is defined in
   section 8.4.2.58 of [IEEE-802.11.2012].  The HT IE is carried by  It contains the 802.11n
   radio capability information.  This document specifies use of the
   IEEE 802.11 Information Element (Type 1029) transporting the IEEE
   802.11 HT information element that defined in section 6.6 of

   [RFC5416] to form carry the 802.11n radio capability message element.
   information.  802.11n Radio Capability message element may radio capability information MAY be included in
   the CAPWAP Configration Configuration Status Request/Response messages.

4.2.

4.1.2.  802.11n Radio Configuration Message Element

   The 802.11n Radio Configuration Information Element message element
   is used by the AC to configure a Radio on the WTP, WTP and by the WTP to
   deliver its radio configuration to the AC.  The 802.11n Radio
   Configuration Information Element is defined in figure 1.  802.11n
   Radio Configuration message element may Message Element MAY be included in the CAPWAP
   Configuration Update Request Request/Response message.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Radio ID   |S|P|N|G|B|     |    MaxSup MCS | Max MandMCS   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    TxAntenna  |    RxAntenna  |         Reserved              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 1: 802.11n Radio Configuration Message Element

   Type: TBD for 802.11n Radio Configuration Message Element.

   Length: 16.

   Radio ID: An 8-bit value representing the radio, whose value is
   between one (1) and 31.

   S bit: A-MSDU Cfg: Enable/disable Aggregate MAC Service Data Unit
   (A-MSDU).  Set to 0 if disabled.  Set to 1 if enabled.

   P bit: A-MPDU Cfg: Enable/disable Aggregate MAC Protocol Data Unit
   (A-MPDU).  Set to 0 if disabled.  Set to 1 if enabled.

   N bit: 11N 11n Only Cfg: Whether to allow only 11n user access.  Set to 0
   if allow non-802.11n user access.  Set to 1 if do not allow
   non-802.11n user access.

   G bit: Short GI Cfg: Set to 0 if disabled.  Set to 1 if enabled.

   B bit: Bandwidth Cfg: Bandwidth binding mode.  Set to 0 if 40MHz
   binding mode.  Set to 1 if 20MHz binding mode.

   Max Support

   MaxSup MCS: Maximal MCS. Maximum Modulation and Coding Scheme (MCS) index.  It
   indicates the maximum MCS index that the WTP or the STA can support.

   Max Mandatory MCS: Maximal mandatory MCS. Maximum Mandatory Modulation and Coding Scheme
   (MCS) index.  Mandatory rates must be supported by the WTP and the
   STA that want to associate with the WTP.

   TxAntenna: Transmitting antenna configuration.  Each TxAntenna bit
   represent one antenna, set a certain number of antennas.  Set to 1 if enabled, set to
   0 if disabled.

   RxAntenna: Receiving antenna configuration.  Each RxAntenna bit
   represent one antenna, set a certain number of antennas.  Set to 1 if enabled, set to
   0 if disabled.

4.3.

   The detail definition of TxAntenna/RxAntenna is as follows:

                        0 1 2 3 4 5 6 7
                       +-+-+-+-+-+-+-+-+
                       |8|7|6|5|4|3|2|1|
                       +-+-+-+-+-+-+-+-+

   Figure 2: Definition of TxAntenna/RxAntenna

   Each bit when enabled will represent the number of antennas
   correspondent to that bit.  For example, when the first bit is
   enabled,it represents 8 antennas.

4.1.3.  802.11n Station Information

   The 802.11n Station Information message element is used to deliver
   IEEE 802.11n station policy from the AC to the WTP.  The definition
   of the 802.11n Station Information message element is in figure 2. 3.
   802.11n Station Information may MAY be included in the CAPWAP Station
   Configuration Request message.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          MAC Address                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            MAC Address        |S| P |T|F|H|M| |  Max RxFactor |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Min StaSpacing|       HiSuppDataRate          | AMPDUBufSize  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | AMPDUBufSize  |    HtcSupp    |           MCS Set             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   MCS Set                                                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   MCS Set                                                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 2: 3: 802.11n Station Information

   Type: TBD for 802.11 Station Information.

   Length: 29. 24.

   S bit: SupChanl width: Supporting bandwidth mode.  0x00: 20MHz
   bandwidth mode.  0x01: 40MHz bandwidth binding mode.

   P flag: Power Save: 0x00: Static power saving mode.  0x01: Dynamic
   power saving mode.  0x03: Do not support power saving mode.

   T bit: ShortGi20: Whether support short GI in 20MHz bandwidth mode.
   0x00: Do not support short GI.  ox01: Support short GI.

   F bit: ShortGi40: Whether support short GI in 40MHz bandwidth mode.
   0x00: Do not support short GI.  ox01: Support short GI.

   H bit: HtDelyBlkack: Whether block Ack support delay mode.  0x00: Do
   not support delay mode.  0x01: Support delay mode.

   M bit: Max Amsdu: The maximal AMSDU length.  0x00: 3839 bytes.  0x01:
   7935 bytes.

   Max RxFactor: The maximal receiving AMPDU factor.

   Min StaSpacing: Minimum MPDU Start Spacing.

   HiSuppDataRate: Maximal transmission speed. speed (Mbps).

   AMPDUBufSize: AMPDU buffer size.

   HtcSupp: Whether the packet have HT header.

   MCS Set: The MCS bitmap that the station supports.

5.  Power and Channel auto reconfiguration Autoconfiguration

   Power and channel auto reconfiguration autoconfiguration could avoid potential radio
   interference and improve the WLAN performance.  In general, the auto-
   configuration of radio power and channel could occur at two stages:
   when the WTP power on or during the WTP running time.

5.1.  Channel Autoconfiguration When WTP Power On

   When the WTP is power-on, it is of necessity to configure a proper
   channel to the WTP in order to achieve best status of radio links.
   IEEE 802.11 Direct Sequence Control elements or IEEE 802.11 OFDM
   Control element defined in RFC5416 should SHOULD be carried in the Configure
   Status Response message to offer WTP a channel at this stage.  Those element should be carried in the
   Configure Status Response message.  If
   those information element is zero, the WTP will need to determine its
   channel by itself, otherwise the WTP
   should SHOULD be configured according
   to the provided information element.

   When the WTP determines its own channel configuration, it should
   first scan the channel information, then determine which channel it
   will work on and form a channel quality scan report.  The channel
   quality report will be sent to the AC using WTP Event Request message
   by the WTP.

   AC will determine whether to change the channel configuration based
   on the received channel quality report.  The AC can use IEEE 802.11
   Direct Sequence Control or IEEE 802.11 OFDM Control information
   element carried by the configure Update Request message to configure
   a new channel for the WTP.

5.2.  Power Configuration When WTP Power On

   IEEE 802.11 Tx Power information element is used by the AC to control
   the transmission power of the WTP.  The 802.11 Tx Power information
   element is carried in the Configure Status Response message during
   the power on phase or in the
   Configure Update Request message during
   the running phase.

   Channel Scan Procedure. message.

5.3.  Channel/Power Auto Adjusment

   The Channel Scan Procedure is illustrated by the figure 3. 4.

                  WTP              Configure Status Req                 AC
                  ------------------------------------------------------->
    Configure Status Res(Scan Para, Chl Bind) Parameter Message Element, Channel Bind Message Element)
                  <------------------------------------------------------
                or

                WTP                                                     AC
    Configure Update Req(Scan Para, Chl Parameter Message Element, Channel Bind Message Element )          AC
                  <-----------------------------------------------------
                                  Configure Update Res
                  ----------------------------------------------------->

   Figure 3: 4: Channel Scan Procedure

5.1.  Scan Parameter Message Element

   The definition of

   WTP has two working modes, the Scan Para Message Element first one is as follows:

       0                   1                   2                   3
    0 1 2 normal working mode.  In
   this mode, the WTP can scan the channel while providing the service
   to STA.  Whether WTP will provide scanning service is determined by
   the Max Cycles value of Channel Bind Message Element.  If this value
   equls to zero, the WTP will not perform scanning.  If this value
   equls to 255, the WTP will scan the channel continuously until
   getting notification from AC.  Otherwise, the WTP will perform
   scanning with the number that specified the value of Max Cycles.  The
   second working mode is scan only mode.  The WTP will not provide
   service to STA in this case.  In this mode, WTP will scan the channel
   continuously.

   When the WTP work in the scan only mode, there is no difference
   between the working channel and scan channel.  Every channel's scan
   duration will be OffChannelScnTime and the PrimeChlSrvTime and
   OnChannelScanTime is set to 0.

   There are two scan types which is determined by the Scan Type value.
   The first type is passive scan.  The WTP will listen the channel
   passively in this case.  The other type is active scan.  The WTP will
   send probe for the scan.  There are three parameters that will
   determine the working mode of scan: PrimeChlSrvTime, On Channel
   ScanTime, Off Channel ScanTime.  The WTP will provide service for the
   period of "PrimeChlSrvTime" time then start channel scan for the
   period of "On Channel ScanTime" time; then continue to provide
   service for the period of "PrimeChlSrvTime" time; then leave the
   current working channel and scan next channel for the period of "Off
   Channel ScanTime" time; then provide service on the next channel for
   the period of "PrimeChlSrvTime"..until finishing the scan procedure.

5.3.1.  Scan Parameter Message Element

   The definition of the Scan Para Message Element is as follows:

              0                   1                   2                   3
             0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |    Radio ID   |M|S|L|D|       |         Report Time           |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |      PrimeChlSrvTime          |     On Channel ScanTime       |
            +-------------------------------+-------------------------------+
            |   Off Channel ScanTime        |
            +-------------------------------+

   Figure 4: 5: Scan Parameter Message Element

   Type: TBD for Scan Parameter Message Element.

   Length: 18. 10.

   Radio ID: An 8-bit value representing the radio, whose value is
   between one (1) and 31.

   M bit: AP oper mode: the work mode of the WTP. 0x01:normal mode.
   0x02: monitor only mode. mode, no service is provided in this mode.ss

   S bit: Scan Type: 0x01: active scan; 0x02: passive scan.

   L bit: L=1: Open Load Balance Scan.  D bit: D=1: Open Rogue WTP
   detection scan.

   Report Time: Channel quality report time. time (unit: second).

   PrimeChlSrvTime: Service time (unit: millisecond) on the working scan
   channel.  This segment is invalid(set to 0) when WTP oper mode is set
   to 2.  The maximum value of this segment is 10000, the minimum value
   of this segment is 5000, the default value is 5000.

   On Channel ScanTime: The scan time (unit: millisecond) of the working
   channel.  When the WTP oper mode is set to 2, this segment is
   invalid(set to 0).  The maximum value of this segment is 120, the
   minimum value of this segment is 60, the default value is 60.

5.2.

5.3.2.  Channel Bind Message Element

   The definition of the Channel Bind Message ELement is as follows:

              0                   1                   2                   3
             0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Radio ID    |   Max Cycles  |Channel Count  |ScanChannelSet.|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 5: Channel Bind Message Element

   Type: TBD for Channel Bind Message Element.

   Length >= 12.

   Flag: bitmap, reserved.

   Max Cycles: Scan repeat times. 255 means continuous scan.

   Channel Count: The number of channel will be scanned.

   Scan Channel Set: The channel information.  The format is as follows:

       0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Channel ID          |              Flag            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 6: Channel Information Format

   Channel ID: the channel ID of the channel which will be scanned.

   Flag: Bitmap, reserved for future use.

   The channel scan procedure:

   The WTP has two work mode: the first one is normal mode.  In this
   mode, the WTP can provide service for the STA access and scan the
   channel at the same time.  Whether the WTP will scan the channel is
   determined by the Max Cycles segment in the Channel Bind TLV.  When
   this segment is set to 0, the WTP will not scan the channle.  If this
   segment is set to 255, the WTP will continuous scan the channel.  The
   type of the scan is determined by the Scan Type segment.  In the
   passive scan type, the WTP monitor the air interface, based on the
   received beacon frame to determine the nearby WTPs.  In the active
   scan type, the WTP will send probe message and receive the probe
   response message.  In the normal scan mode, the WTP will use 3
   parameters: PrimeChlSrvTime, OnChannelScanTIme, OffChannelScnTIme.
   The WTP will provide access service 6 7 8 9 0 1
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |   Radio ID    |   Max Cycles  |Channel Count  |ScanChannelSet.|
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 6: Channel Bind Message Element

   Type: TBD for Channel Bind Message Element.

   Length: 4.

   Radio ID: An 8-bit value representing the STAs for PrimeChlSrvTime
   duration radio, whose value is
   between one (1) and then start to scan the channel for On 31.

   Flag: bitmap, reserved.

   Max Cycles: Scan repeat times. 255 means continuous scan.

   Channel ScnTime
   duration.  Back to the working channel, provide STA access service
   for PrimeChlSrvTime, then leave the working channel, start to scan
   the next Count: The number of channel for Off Channel ScanTime duration.  This process will be repeated until all the scanned.

   Scan Channel Set: The channel information.  The format is scanned.

   When the WTP work in as follows:

              0                   1                   2                   3
             0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |            Channel ID          |              Flag            |
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 7: Channel Information Format
   Channel ID: the scan only mode, there is no difference
   between channel ID of the working channel and scan channel.  Every channel's scan
   duration which will be OffChannelScnTime and the PrimeChlSrvTime scanned.

   Flag: Bitmap, reserved for future use.

5.3.3.  Channel Scan Report

   There are two types of scan report: Channel Scan Reprot and
   OnChannelScanTime Neighbor
   STA Reprot.  Channel Scan Report is set used to 0.

   Scan Report. channel autoconfiguration
   while Neighbor WTP Report is used to power autoconfiguration.  The
   WTP send the scan report to the AC through WTP Event Request message.
   The information element that used to carry the scan report is Channel
   Scan Report Message Element and Neighbor WTP Report Message Element.

5.3.  Channel Scan Report

   The definition of the Channel Scan Report Message Element is in
   figure 7. 8.

              0                   1                   2                   3
             0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            | Radio ID     | Report Count    |    Channel Scan Report       |
            +---------------------------------------------------------------+

   Figure 7: 8: Channel Scan Report Message Element

   Type: TBD for Channel Scan Report Message Element.

   Length: >=29.

   Radio ID: An 8-bit value representing the radio, whose value is
   between one (1) and 31.

   Report Count: The channel number will be reported.

   Channel Scan Report: The definition of the Channel Scan Report is in
   figure 8. 9.  It complies with the IEEE 802.11 Beacon report that
   defined in section 8.4.2.24.7 of [IEEE-802.11.2012].

              0                   1                   2                   3
             0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |Operating Class|Channel Number |Actual Measurement Start Time..|
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            |        ...Actual Measurement Start Time                       |
            |-------------------------------+-------------------------------+
            |..Actual Measurement Start Time|    Measurement Duration       |
            +---------------+---------------+-------------------------------+
            |Reported Frame |    RCPI       |      BSSID...                 |
            +---------------+---------------+-------------------------------+
            |                         ...BSSID                              |
            +---------------+-----------------------------------------------+
            | Antena ID     |          Parent TSF...                        |
            +---------------+-----------------------------------------------+
            |...Parent TSF  | Optional Subelements(variable)                |
            +---------------+-----------------------------------------------+

   Figure 8: 9: Channel Scan Report

   Operating Class: Indicates the channel set for which the measurement
   request applies.  Country.  The definition of this field complies with the
   definition in section 8.4.2.24.7 of [IEEE-802.11.2012].

   Channel Number: Indicates the channel number for which the
   measurement report applies.  The definition of this field complies
   with the definition in section 8.4.2.24.7 of [IEEE-802.11.2012].

   Actual Measurement Start Time: Is set to the value of the measuring
   STA's TSF timer at the time the measurement started.

   Measurement Duration: Is set to the duration over which the Beacon
   Report was measured.  The definition of this field complies with the
   definition in section 8.4.2.24.7 of [IEEE-802.11.2012].

   Reported Frame Information: This field contains two subfields as
   defined in [IEEE-802.11.2012].

   RCPI: Indicates the received channel power of the Beacon, Measurement
   Pilot, or Probe Response frame.

   RSNI:Indicates the received signal to noise indication for the
   Beacon, Measurement Pilot, or Probe Response frame.

   BSSID: This field contains the BSSID from the Beacon,Measurement
   Pilot, or Probe Response frame being reported.

   Antenna ID: This field contains the identifying number for the
   antennas used for this measurement.

   Parent TSF: This field contains the lower 4 octets of the measuring
   STA's TSF timer value at the start of reception of the first octet of
   the timestamp field of the reported Beacon, Measurement Pilot, or
   Probe Response frame at the time the Beacon frame being reported was
   received.

   Optional Subelements: This field contains zero or more subelements.

5.4.

5.3.4.  Neighbor WTP Report

   The neighbor WTP report message element is composed of the IEEE
   802.11 Information Element that defined in section 6.6 of [RFC5416]
   and IEEE 802.11 Neighbor Report Element that defined in section
   8.4.2.39 of [IEEE-802.11.2012].  The Neighbor Report Element is
   carried by the IEEE 802.11 Information Element to form the neighbor
   WTP report message element.

6.  Security Considerations

   This document is based on RFC5415/RFC5416 and it doesn't increase any
   security risk.  The security considerations of this document aligns
   with RFC5415/5416.

7.  IANA Considerations

   The extension defined in this document need to extend CAPWAP IEEE
   802.11 binding message element which is defined in section 6 of
   [RFC5416].  The following IEEE 802.11 specific message element type
   need to be defined by IANA.

   802.11n Radio Configuration Message Element type value described in
   section 4.2. 4.1.2.

   802.11n Station Message Element type value described in section 4.3.
   4.1.3.

   Scan Parameter Message Element type value described in section 5.1. 5.3.1.

   Channel Bind Message Element type value described in section 5.2. 5.3.2.

   Channel Scan Report Message Element type value described in section
   5.3.
   5.3.3.

8.  Contributors

   This draft is a joint effort from the following contributors:

   Gang Chen: China Mobile chengang@chinamobile.com

   Naibao Zhou: China Mobile zhounaibao@chinamobile.com

   Chunju Shao: China Mobile shaochunju@chinamobile.com

   Hao Wang: Huawei3Come hwang@h3c.com

   Yakun Liu: AUTELAN liuyk@autelan.com

   Xiaobo Zhang: GBCOM

   Xiaolong Yu: Ruijie Networks

   Song zhao: ZhiDaKang Communications

   Yiwen Mo: ZhongTai Networks

9.  Acknowledgements

   The authors would like to thanks Ronald Bonica,Romascanu Dan, Benoit
   Claise, Melinda Shore and Margaret Wasserman for their useful
   suggestions.  The authors also thanks Dorothy Stanley's Stanley and Tom Taylor
   for their review and useful comments.

10.  Normative References

   [IEEE-802.11.2009]
              ,
              "IEEE Standard for Information technology -
              Telecommunications and information exchange between
              systems Local and metropolitan area networks - Specific
              requirements Part 11: Wireless LAN Medium Access Control
              (MAC) and Physical Layer (PHY) Specifications ", Specifications", 2009.

   [IEEE-802.11.2012]
              ,
              "IEEE Standard for Information technology -
              Telecommunications and information exchange between
              systems Local and metropolitan area networks - Specific
              requirements Part 11: Wireless LAN Medium Access Control
              (MAC) and Physical Layer (PHY) Specifications ", Specifications", March
              2012.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4564]  Govindan, S., Cheng, H., Yao, ZH., Zhou, WH., and L. Yang,
              "Objectives for Control and Provisioning of Wireless
              Access Points (CAPWAP)", RFC 4564, July 2006.

   [RFC5415]  Calhoun, P., Montemurro, M., and D. Stanley, "Control And
              Provisioning of Wireless Access Points (CAPWAP) Protocol
              Specification", RFC 5415, March 2009.

   [RFC5416]  Calhoun, P., Montemurro, M., and D. Stanley, "Control and
              Provisioning of Wireless Access Points (CAPWAP) Protocol
              Binding for IEEE 802.11", RFC 5416, March 2009.

Authors' Addresses

   Yifan Chen
   China Mobile
   No.32 Xuanwumen West Street
   Beijing  100053
   China

   Email: chenyifan@chinamobile.com

   Dapeng Liu
   China Mobile
   No.32 Xuanwumen West Street
   Beijing  100053
   China

   Email: liudapeng@chinamobile.com

   Hui Deng
   China Mobile
   No.32 Xuanwumen West Street
   Beijing  100053
   China

   Email: denghui@chinamobile.com

   Lei Zhu
   Huawei
   No. 156, Shi-Chuang-Ke-Ji-Shi-Fan-Yuan Beiqing Road, Haidian District
   Beijing 100095
   China

   Email: lei.zhu@huawei.com