Network Working Group                                          Y.F.                                            Y. Chen
Internet-Draft                                                  D.L.                                                    D. Liu
Intended status: Standards Track                                 H. Deng
Expires: November 10, 2013 Apr, 2014                                 China Mobile
                                                                Lei. Zhu
                                                                  Huawei
                                                            May 09,
                                                                Oct 2013

     CAPWAP Extension for 802.11n and Power/channel Reconfiguration
                 draft-ietf-opsawg-capwap-extension-00
                 draft-ietf-opsawg-capwap-extension-01

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 several new amendent amendment of 802.11 has been published.
   802.11n is one of those amendent amendment and it has been widely used in real
   deployment.  This document extends the CAPWAP binding for 802.11 to
   support 802.11n. 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 November 10, 2013.

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   2
   3.  CAPWAP 802.11n support  . . . . . . . . . . . . . . . . . . .   2
   4.  CAPWAP extension for 802.11n support  . . . . . . . . . . . .   3
     4.1.  802.11n Radio Capability Message Element  . . . . . . . .   3
     4.2.  802.11n Radio Configuration Message Element . . . . . . .   4
     4.3.  802.11n Station Information . . . . . . . . . . . . . . .   5
   5.  Power and Channel auto reconfiguration  . . . . . . . . . . .   6
     5.1.  Scan Parameter Message Element  . . . . . . . . . . . . .   7
     5.2.  Channel Bind Message Element  . . . . . . . . . . . . . .   8
     5.3.  Channel Scan Report . . . . . . . . . . . . . . . . . . .   9
     5.4.  Neighbor WTP Report . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13  12
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13  12
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  13  12
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   10. Normative References  . . . . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14  13

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.  The
   maximum data rate increases to 600Mbit/s physical throughput rate.
   In the physical layer, 802.11n use OFDM and MIMO to achive achieve the high
   throughput. 802.11n use multiple antennas to form antenna array which
   can be dynamically adjusted to imporve improve the signal strength and extend
   the coverage.

   There are couple of capabilities of 802.11n need to be supported by
   CAPWAP control message such as radio capability, radio configuration
   and station information.

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.  CAPWAP 802.11n support

   IEEE 802.11n

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

   802.11n support three modes of channel usage: 20MHz mode, 40Mhz 40MHz mode
   and mixed 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 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 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 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 and the access controller should be able
   to configure the differe different channel binding modes.  One possible
   solution is to extend  This document
   defines extension of the CAPWAP information element for 802.11n. 802.11 binding to support 802.11n
   features.

4.  CAPWAP extension for 802.11n support

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

   1. 802.11n features.

4.1.  802.11n Radio Capability Message Element

   [RFC5416] defines IEEE 802.11 binding for CAPWAP protocol.  It
   defines IEEE 802.11 Information Element.  Below Element which is an
   example of the 802.11n radio capability information element. used to communicate
   any IE defined in IEEE 802.11 protocol.  This document defines
   802.11n radio capability information element may also be conveyed
   using which is composed of the
   IEEE 802.11 Information Element header that defined in section 6.6 of
   [RFC5416] and the IEEE 802.11 HT information element that defined in
   section 8.4.2.58 of [IEEE-802.11.2012].  The HT IE is carried by carrying the
   IEEE 802.11
   HT information element information.

   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID         |              Length           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Radio ID   |SupChanl width |   Power Save   |  ShortGi20   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  ShortGi40    | HtDelyBlkack  |  Max Amsdu     |  Max RxFactor|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Min StaSpacing | HiSuppDataRate|   AMPDUBufSize |   HtcSupp    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |                        20MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        20MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11gMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        40MHZ 11aMCS                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 1: 802.11n Radio Capability Information Element

   1.   SupChanl width: The supported bandwith mode.  0x01: 20MHz
        bandwidth binding mode.  0x02: 40MHz bandwidth binding mode.
   2.   Power Save: 0x00: Static power saving mode.  0x01: Dynamic power
        saving mode.  0x03: Do not support power saving mode.
   3.   ShortGi20: Whether support short GI.  0x00: Do not support short
        GI.  ox01: Support short GI.
   4.   HtDelyBlkack: Whether block Ack support delay mode.  0x00: Do
        not support delay mode.  0x01: Support delay mode.
   5.   Max Amsdu: The maximal AMSDU length.  0: 3839 bytes.  1: 7935
        bytes.
   6.   Max RxFactor: The maximal receiving AMPDU factor.  Default
        value: 3.
   7.   Min StaSpacing: Minimum MPDU Start Spacing.
   8.   HiSuppDataRate: Maximal transmission speed.

   9.   AMPDUBufSize: AMPDU buffer size.
   10.  HtcSupp: Whether that defined in section 6.6 of

   [RFC5416] to form the packet have HT header.
   11.  20MHZ 11gMCS: 128 bitmap.If support should be all zero,
        otherwise all one.
   12.  20MHZ 11aMCS: 128 bitmap.If support should be all zero,
        otherwise all one.
   13.  40MHZ 11gMCS: 128 bitmap.If support should be all zero,
        otherwise all one.
   14.  40MHZ 11aMCS: 128 bitmap.If support should 802.11n radio capability message element.
   802.11n Radio Capability message element may be all zero,
        otherwise all one.
   15.  2. included in the
   CAPWAP Configration Status Request/Response messages.

4.2.  802.11n Raido Radio Configuration TLV.  Following figure is an
        example of Message Element

   The 802.11n Radio Configuration Information Element message element
   is used by the AC to configure a Radio on the WTP, and by the WTP to
   deliver its radio configuration TLV. to the AC.  The 802.11n Radio
   Configuration Information Element is defined in figure 1.  802.11n
   Radio Configuration message element may be included in the CAPWAP
   Configuration Update 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |              Length           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Radio ID   |S|P|N|G|B|     |   Amsdu Cfg   |   Ampdu Cfg   |  11nOnly Cfg  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | ShortGi Cfg   | BandWidth Cfg |  MaxSupp    MaxSup MCS | Max MandMCS   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    TxAntenna  |    RxAntenna  |         Reserved              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Reserved                            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 2: 1: 802.11n radio configuration

   1. Radio Configuration Message Element

   Type: TBD for 802.11n Radio Configuration Message Element.

   Length: 16.

   S bit: A-MSDU CFG: 0x00: Disable 0x01: Enalbe
   2. Cfg: Set to 0 if disabled.  Set to 1 if enabled.

   P bit: A-MPDU CFG: 0x00: Disable 0x01: Enalbe
   3. Cfg: Set to 0 if disabled.  Set to 1 if enabled.

   N bit: 11N Only CFG: Cfg: Whether allow only 11n user access.  0x00: Allow  Set to 0 if
   allow non-802.11n user access.  0x01: Do  Set to 1 if do not allow non-802.11n
   user access.
   4.

   G bit: Short GI CFG: 0x00: Disable 0x01: Enable
   5. Cfg: Set to 0 if disabled.  Set to 1 if enabled.

   B bit: Bandwidth CFG: Cfg: Bandwidth binding mode.  0x00:  Set to 0 if 40MHz 0x01:
   binding mode.  Set to 1 if 20MHz
   6. binding mode.

   Max Support MCS: Maximal MCS.
   7.

   Max Mandantory Mandatory MCS: Maximal mandantory mandatory MCS.
   8.

   TxAntenna: Transmitting antenna configuration.
   9.  Each TxAntenna bit
   represent one antenna, set to 1 if enabled, set to 0 if disabled.

   RxAntenna: Receiving antenna configuration.
   10.  Each TxAntenna and RxAntenna bit
   represent one antenna, set to 1 means
        enable, if enabled, set to 0 means disable.

   3. if disabled.

4.3.  802.11n Station Information.  Following figure Information

   The 802.11n Station Information message element is an example of used to deliver
   IEEE 802.11n station information information element. policy from the AC to the WTP.  The definition
   of the 802.11n Station Information message element is in figure 2.
   802.11n Station Information 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |              Length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          MAC Address                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |SupChanl width |   Power Save  |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  ShortGi20
   | ShortGi40     | HtDelyBlkack  |  Max Amsdu    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+            MAC Address        |S| P |T|F|H|M| |  Max RxFactor |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Min StaSpacing|       HiSuppDataRate          | AMPDUBufSize  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | AMPDUBufSize  |    HtcSupp    |           MCS Set             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   MCS Set                                                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   MCS Set                                                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     MCS Set    |
   +-+-+-+-+-+-+-+-+-

   Figure 3: 2: 802.11n Station Information

   1.

   Type: TBD for 802.11 Station Information.

   Length: 29.

   S bit: SupChanl width: Supporting bandwidth mode.  0x01:  0x00: 20MHz
   bandwidth mode.  0x02:  0x01: 40MHz bandwidth binding mode.
   2.

   P flag: Power Save: 0x00: Static power saving mode.  0x01: Dynamic
   power saving mode.  0x03: Do not support power saving mode.
   3.

   T bit: ShortGi20: Whether support short GI in 20MHz bandwidth mode.
   0x00: Do not support short GI.  ox01: Support short GI.
   4.

   F bit: ShortGi40: Whether support short GI in 40MHz bandwidth mode.
   0x00: Do not support short GI.  ox01: Support short GI.
   5.

   H bit: HtDelyBlkack: Whether block Ack support delay mode.  0x00: Do
   not support delay mode.  0x01: Support delay mode.
   6.

   M bit: Max Amsdu: The maximal AMSDU length.  0x00: 3839 bytes.  0x01:
   7935 bytes.
   7.

   Max RxFactor: The maximal receiving AMPDU factor.
   8.

   Min StaSpacing: Minimum MPDU Start Spacing.
   9.

   HiSuppDataRate: Maximal transmission speed.
   10.

   AMPDUBufSize: AMPDU buffer size.
   11.

   HtcSupp: Whether the packet have HT header.
   12.

   MCS Set: The MCS bitmap that the station supports.

5.  Power and Channel auto reconfiguration

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

   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 be carried 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 determine its channel by itself, otherwise the WTP
   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.  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.

   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.

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

         WTP              Configure Status Req                 AC
         ------------------------------------------------------->
           Configure Status Res(Scan Para TLV, Para, Chl Bind TLV) Bind)
         <------------------------------------------------------
       or

       WTP Configure Update Req(Scan Para, Chl Bind TLV) )          AC
         <-----------------------------------------------------
                         Configure Update Res
         ----------------------------------------------------->

   Figure 4: 3: Channel Scan Procedure

5.1.  Scan Parameter Message Element

   The definition of the Scan Para TLV 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |              Length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Radio    Radio ID |   AP oper mode                       |   Scan Type  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Reserved                              |
   +---------------------------------------------------------------+   |M|S|L|D|       |         Report Time           |      PrimeChlSrvTime
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |
   +---------------------------------------------------------------+      PrimeChlSrvTime          |     On Channel ScanTIme ScanTime       |
   +-------------------------------+-------------------------------+
   |   Off Channel ScanTime        |
   +---------------------------------------------------------------+
   |L|D|         Flag               |                              |
   +---------------------------------------------------------------+
   +-------------------------------+

   Figure 5: 4: Scan Para TLV Parameter Message Element

   Type: TBD for Scan Parameter Message Element.

   Length: 18.

   Radio ID: TBD; Length:18 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.

   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.

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

   L=1: Open Load Balance Scan.  D=1: Open Rogue WTP detection scan.
   Flag: Bitmap, resered for furture use.

5.2.  Channel Bind Message Element

   The definition of the Channel Bind TLV 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |              Length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Radio   Radio ID    |                        Flag                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Max Cycles  |      Reserved         |    Channel  |Channel Count     |
   +---------------------------------------------------------------+
   |                      Scan Channel Set...                      |
   +---------------------------------------------------------------+  |ScanChannelSet.|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 6: 5: Channel Bind TLV Message Element ID: TBD.  Length>=12

   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 channle channel information.  the  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 7: Channle 6: Channel Information Format

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

   Flag: bitmap, Bitmap, reserved for future use.

   The channle 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 Channle 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 Sacn Scan Type segment.  In the
   passive scan type, the WTP monitor the airinterface, 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 for the STAs for PrimeChlSrvTime
   duration and then start to scan the channel for On Channel ScnTime
   duration.  Back to the working channel, provide STA access service
   for PrimeChlSrvTime, then leave the working channel, start to scan
   the next channel for Off Channel ScanTime duration.  This process
   will be repeated until all the channel is scanned.

   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.

   Scan Report.  THe  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 TLV and Neighbor WTP Report
   TLV.  The example definition of the Channel Scan Report TLV is as
   following figure.  The channel scan report may also be conveyed by
   IEEE 802.11 information element by carrying the IEEE 802.11 beacon
   report message element.

   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |             Length           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Radio ID     | Report Count    | Channel Scan Report          |
   +---------------------------------------------------------------+

   Figure 8: Message Element and Neighbor
   WTP Report Message Element.

5.3.  Channel Scan Report TLV

   Element ID: 133; Length: >= 20.

   Report Count: the channle number will be reported.
   The definition of the channel scan report Channel Scan Report Message Element is as follows: in
   figure 7.

       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 Number   |      Radar Statistics       | Mean     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Time    | Mean RSSI Radio ID     | Screen Packet Report Count    |
   +---------------------------------------------------------------+
   | NeighborCount| Mean Noise   | Interference  | Self Tx Occp    |
   +---------------------------------------------------------------+
   | SelfStaOccp  | Unknown Occp |  CRC Err Cnt  | Decrypt Err Cnt    Channel Scan Report       |
   +---------------------------------------------------------------+
   |Phy Err Cnt   | Retrans Cnt  |
   +-----------------------------+

   Figure 9: 7: Channel Scan Report Message Element

   Type: TBD for Channel Number: The channel number.

   Radar Statistics: Whether detect radar signal in this channel.  0x00:
   detect radar signal.  0x01: no radar signal is detected.

   Mean Time: Channel measurement duration.

   Mean RSSI: The signal strength of the scanned channel.

   Screen Packet Count: Received packet number.

   Neighbor Scan Report Message Element.

   Length: >=29.

   Report Count: The neighbor channel number of this channel.

   Mean Noise: the average noise on this channel.

   Interference: The interference of the channel.

   Self Tx Occp: The time duration for transmission.

   Unknown Occp: TBD.

   CRC Err Cnt: CRC err packet number.

   Decrypt Err Cnt: Decryption err packet number.

   Phy Err Cnt: Physical err packet number.

   Retrans Cnt: Retransmission packet number. will be reported.

   Channel Scan Report: The example definition of neighbor WTP report TLV the Channel Scan Report is as follows:

   The neigbor WTP report message element may also be conveyed using in
   figure 8.  It complies with the IEEE 802.11 information element by carrying 802.11 neighbor Beacon report
   information element. 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Element ID          |             Length           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Radio ID     | Reserved        |
   |Operating Class|Channel Number of Neighbor Report |Actual Measurement Start Time..|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |
   +---------------------------------------------------------------+        ...Actual Measurement Start Time                       | Neighbor Infor...
   |-------------------------------+-------------------------------+
   |..Actual Measurement Start Time|    Measurement Duration       |
   +---------------------------------------------------------------+

   Figure 10: Neighbor WTP Report TLV

   Element ID: 134; Length:>=16

   The definition of Neighbor info 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   +---------------+---------------+-------------------------------+
   |Reported Frame |                            BSSID    RCPI       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+      BSSID...                 |            BSSID
   +---------------+---------------+-------------------------------+
   |        Channel Number                         ...BSSID                              |
   +---------------------------------------------------------------+
   +---------------+-----------------------------------------------+
   | 2rd Offset Antena ID     |  Mean RSSI          Parent TSF...                        | Sta Intf
   +---------------+-----------------------------------------------+
   |...Parent TSF  |    AP Intf Optional Subelements(variable)                |
   +---------------------------------------------------------------+
   +---------------+-----------------------------------------------+
   Figure 11: Neighbor info

   BSSID: 8: Channel Scan Report

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

   Channel Number: The Indicates the channel number for which the
   measurement report applies.  The definition of this neighbor channel.

   2rd channel offset: TBD.

   Mean RSSI: 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 average 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 strength 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 channel.

   Sta Intf: TBD.

   AP Intf: TBD. 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.  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 RFC 5416.  the
   corresponding section 6 of
   [RFC5416].  The following IEEE 802.11 specific message element type values
   need to be defined by IANA.

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

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

   Scan Parameter Message Element type value described in section 5.1.

   Channel Bind Message Element type value described in section 5.2.

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

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
   Claise, Melinda Shore and Margaret Wasserman for their usefull useful
   suggestions.  The authors also thanks Dorothy Stanley's 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 ", 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 ", 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