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Checking references for intended status: Informational ---------------------------------------------------------------------------- == Unused Reference: 'RFC4564' is defined on line 564, but no explicit reference was found in the text == Unused Reference: 'RFC5415' is defined on line 568, but no explicit reference was found in the text Summary: 0 errors (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Y. Chen 3 Internet-Draft D. Liu 4 Intended status: Informational H. Deng 5 Expires: August 5, 2013 China Mobile 6 Lei. Zhu 7 Huawei 8 Feb 2013 10 CAPWAP Extension for 802.11n and Power/channel Reconfiguration 11 draft-chen-opsawg-capwap-extension-00 13 Abstract 15 CAPWAP binding for 802.11 is specified by RFC5416 and it was based on 16 IEEE 802-11.2007 standard. After RFC5416 was published in 2009, 17 there was several new amendent of 802.11 has been published. 802.11n 18 is one of those amendent and it has been widely used in real 19 deployment. This document extends the CAPWAP binding for 802.11 to 20 support 802.11n. 22 Status of this Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on August 5, 2013. 39 Copyright Notice 41 Copyright (c) 2013 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (http://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 2. Conventions used in this document . . . . . . . . . . . . . . 3 58 3. CAPWAP 802.11n support . . . . . . . . . . . . . . . . . . . . 3 59 4. CAPWAP extension for 802.11n support . . . . . . . . . . . . . 4 60 5. Power and Channel auto reconfiguration . . . . . . . . . . . . 8 61 6. Security Considerations . . . . . . . . . . . . . . . . . . . 13 62 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 63 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 14 64 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14 65 10. Normative References . . . . . . . . . . . . . . . . . . . . . 14 66 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 68 1. Introduction 70 IEEE 802.11n standard was published in 2009 and it is an amendment to 71 the IEEE 802.11-2007 standard to improve network throughput. The 72 maximum data rate increases to 600Mbit/s physical throughput rate. 73 In the physical layer, 802.11n use OFDM and MIMO to achive the high 74 throughput. 802.11n use multiple antennas to form antenna array which 75 can be dynamically adjusted to imporve the signal strength and extend 76 the coverage. 78 There are couple of capabilities of 802.11n need to be supported by 79 CAPWAP control message such as radio capability, radio configuration 80 and station information. 82 2. Conventions used in this document 84 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT", 85 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 86 document are to be interpreted as described in [RFC2119]. 88 3. CAPWAP 802.11n support 90 IEEE 802.11n standard was published in 2009 and it is an amendment to 91 the IEEE 802.11-2007 standard to improve network throughput. The 92 maximum data rate increases to 600Mbit/s physical throughput rate. 93 In the physical layer, 802.11n use OFDM and MIMO to achive the high 94 throughput. 802.11n use multiple antennas to form antenna array which 95 can be dynamically adjusted to imporve the signal strength and extend 96 the coverage. 98 802.11n support three modes of channel usage: 20MHz mode, 40Mhz mode 99 and mixed mode.802.11n has a new feature called channel binding. It 100 can bind two adjacent 20MHz channel to one 40MHz channel to improve 101 the throughput.If using 40Mhz channel configuration there will be 102 only one non-overlapping channel in 2.4GHz. In the large scale 103 deployment scenario, operator need to use 20MHz channel configuration 104 in 2.4GHz to allow more non-overlapping channels. 106 In MAC layer, a new feature of 802.11n is Short Guard Interval(GI). 107 802.11a/g use 800ns guard interval between the adjacent information 108 symbols. In 802.11n, the GI can be configured to 400nm under good 109 wireless condition. 111 Another feature in 802.11 MAC layer is Block ACK. 802.11n can use one 112 ACK frame to acknowledge several MPDU receiving event. 114 CAPWAP need to be extended to support the above new 802.11n features. 115 For example, CAPWAP should allow the access controller to know the 116 supported 802.11n features and the access controller should be able 117 to configure the differe channel binding modes. One possible 118 solution is to extend the CAPWAP information element for 802.11n. 120 4. CAPWAP extension for 802.11n support 122 There are couple of capabilities of 802.11n need to be supported by 123 CAPWAP control message such as radio capability, radio configuration 124 and station information. This section defines the extension of 125 current CAPWAP 802.11 information element to support 802.11n. 127 1. 802.11n Radio Capability Information Element. The information 128 element need to be extended to include 802.11n radio capability. 129 Below is an example of the 802.11n radio capability information 130 element. 132 0 1 2 3 133 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 1 134 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 135 | Element ID | Length | 136 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 137 | Radio ID |SupChanl width | Power Save | ShortGi20 | 138 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 139 | ShortGi40 | HtDelyBlkack | Max Amsdu | Max RxFactor| 140 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 141 |Min StaSpacing | HiSuppDataRate| AMPDUBufSize | HtcSupp | 142 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 | 20MHZ 11gMCS | 144 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 145 | 20MHZ 11gMCS | 146 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 147 | 20MHZ 11gMCS | 148 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 149 | 20MHZ 11gMCS | 150 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 151 | 20MHZ 11aMCS | 152 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 153 | 20MHZ 11aMCS | 154 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 155 | 20MHZ 11aMCS | 156 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 157 | 20MHZ 11aMCS | 158 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 159 | 40MHZ 11gMCS | 160 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 161 | 40MHZ 11gMCS | 162 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 163 | 40MHZ 11gMCS | 164 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 165 | 40MHZ 11gMCS | 166 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 167 | 40MHZ 11aMCS | 168 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 | 40MHZ 11aMCS | 170 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 171 | 40MHZ 11aMCS | 172 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 173 | 40MHZ 11aMCS | 174 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 1. SupChanl width: The supported bandwith mode. 0x01: 20MHz 177 bandwidth binding mode. 0x02: 40MHz bandwidth binding mode. 179 2. Power Save: 0x00: Static power saving mode. 0x01: Dynamic power 180 saving mode. 0x03: Do not support power saving mode. 181 3. ShortGi20: Whether support short GI. 0x00: Do not support short 182 GI. ox01: Support short GI. 183 4. HtDelyBlkack: Whether block Ack support delay mode. 0x00: Do not 184 support delay mode. 0x01: Support delay mode. 185 5. Max Amsdu: The maximal AMSDU length. 0: 3839 bytes. 1: 7935 186 bytes. 187 6. Max RxFactor: The maximal receiving AMPDU factor. Default 188 value: 3. 189 7. Min StaSpacing: Minimum MPDU Start Spacing. 190 8. HiSuppDataRate: Maximal transmission speed. 191 9. AMPDUBufSize: AMPDU buffer size. 192 10. HtcSupp: Whether the packet have HT header. 193 11. 20MHZ 11gMCS: 128 bitmap.If support should be all zero, 194 otherwise all one. 195 12. 20MHZ 11aMCS: 128 bitmap.If support should be all zero, 196 otherwise all one. 197 13. 40MHZ 11gMCS: 128 bitmap.If support should be all zero, 198 otherwise all one. 199 14. 40MHZ 11aMCS: 128 bitmap.If support should be all zero, 200 otherwise all one. 201 15. 2. 802.11n Raido Configuration TLV. Following figure is an 202 example of 802.11n radio configuration TLV. 204 0 1 2 3 205 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 1 206 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 207 | Element ID | Length | 208 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 209 | Radio ID | Amsdu Cfg | Ampdu Cfg | 11nOnly Cfg | 210 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 211 | ShortGi Cfg | BandWidth Cfg | MaxSupp MCS | Max MandMCS | 212 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 213 | TxAntenna | RxAntenna | Reserved | 214 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 215 | Reserved | 216 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 218 1. A-MSDU CFG: 0x00: Disable 0x01: Enalbe 219 2. A-MPDU CFG: 0x00: Disable 0x01: Enalbe 220 3. 11N Only CFG: Whether allow only 11n user access. 0x00: Allow 221 non-802.11n user access. 0x01: Do not allow non-802.11n user 222 access. 223 4. Short GI CFG: 0x00: Disable 0x01: Enable 224 5. Bandwidth CFG: Bandwidth binding mode. 0x00: 40MHz 0x01: 20MHz 225 6. Max Support MCS: Maximal MCS. 226 7. Max Mandantory MCS: Maximal mandantory MCS. 227 8. TxAntenna: Transmitting antenna configuration. 228 9. RxAntenna: Receiving antenna configuration. 229 10. Each TxAntenna and RxAntenna bit represent one antenna, 1 means 230 enable, 0 means disable. 232 3. 802.11n Station Information. Following figure is an example of 233 802.11n station information information element. 235 0 1 2 3 236 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 1 237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 | Element ID | Length | 239 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 240 | MAC Address | 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 |SupChanl width | Power Save | | 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 | ShortGi20 | ShortGi40 | HtDelyBlkack | Max Amsdu | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 | Max RxFactor | Min StaSpacing| HiSuppDataRate | 247 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 | AMPDUBufSize | HtcSupp | MCS Set | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | MCS Set | 251 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 252 | MCS Set | 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 | MCS Set | 255 +-+-+-+-+-+-+-+-+- 257 1. SupChanl width: Supporting bandwidth mode. 0x01: 20MHz bandwidth 258 mode. 0x02: 40MHz bandwidth binding mode. 259 2. Power Save: 0x00: Static power saving mode. 0x01: Dynamic power 260 saving mode. 0x03: Do not support power saving mode. 261 3. ShortGi20: Whether support short GI in 20MHz bandwidth mode. 262 0x00: Do not support short GI. ox01: Support short GI. 263 4. ShortGi40: Whether support short GI in 40MHz bandwidth mode. 264 0x00: Do not support short GI. ox01: Support short GI. 265 5. HtDelyBlkack: Whether block Ack support delay mode. 0x00: Do not 266 support delay mode. 0x01: Support delay mode. 267 6. Max Amsdu: The maximal AMSDU length. 0x00: 3839 bytes. 0x01: 268 7935 bytes. 269 7. Max RxFactor: The maximal receiving AMPDU factor. 270 8. Min StaSpacing: Minimum MPDU Start Spacing. 272 9. HiSuppDataRate: Maximal transmission speed. 273 10. AMPDUBufSize: AMPDU buffer size. 274 11. HtcSupp: Whether the packet have HT header. 275 12. MCS Set: The MCS bitmap that the station supports. 277 5. Power and Channel auto reconfiguration 279 Power and channel auto reconfiguration could avoid potential radio 280 interference and improve the Wi-Fi performance. In general, the 281 auto-configuration of radio power and channel could occurre at two 282 stages: when the AP power on or during the AP running time. 284 When the AP is power-on, it is of necessity to configure a proper 285 channel to the AP in order to achieve best status of radio links. 286 IEEE 802.11 Direct Sequence Control elements or IEEE 802.11 OFDM 287 Control element defined in RFC5416 should be carried to offer AP a 288 channel at this stage. Those element should be carried in the 289 Configure Status Response message. If those information element is 290 zero, the AP will determine its channel by itself, otherwise the AP 291 should be configured according to the provided information element. 293 When the AP determines its own channel configuration, it should first 294 scan the channel information, then determine which channel it will 295 work on and form a channel quality scan report. The channel quality 296 report will be sent to the AC using WTP Event Request message by the 297 AP. The AC can use IEEE 802.11 Direct Sequence Control or IEEE 298 802.11 OFDM Control information element carried by the configure 299 Update Request message to configure a new channel for the AP. 301 IEEE 802.11 Tx Power information element is used by the AC to control 302 the transmission power of the AP. The 802.11 Tx Power information 303 element is carried in the Configure Status Response message during 304 the power on phase or in the Configure Update Request message during 305 the running phase. 307 Channel Scan Procedure. 309 The Channel Scan Procedure is illustrated by the following figure. 311 WTP Configure Status Req AC 312 -------------------------------------------------------> 313 Configure Status Res(Scan Para TLV, Chl Bind TLV) 314 <------------------------------------------------------ 315 or 317 WTP Configure Update Req(Scan Para, Bind TLV) AC 318 <----------------------------------------------------- 319 Configure Update Res 320 -----------------------------------------------------> 322 The definition of the Scan Para TLV is as follows: 324 0 1 2 3 325 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 1 326 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 327 | Element ID | Length | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 |Radio ID | AP oper mode | Scan Type | 330 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 331 | Reserved | 332 +---------------------------------------------------------------+ 333 | Report Time | PrimeChlSrvTime | 334 +---------------------------------------------------------------+ 335 | On Channel ScanTIme | Off Channel ScanTime | 336 +---------------------------------------------------------------+ 337 |L|D| Flag | | 338 +---------------------------------------------------------------+ 340 Element ID: TBD; Length:18 342 AP oper mode: the work mode of the AP. 0x01:normal mode. 0x02: 343 monitor only mode. 345 Scan Type: 0x01: active scan; 0x02: passive scan. 347 Report Time: Channel quality report time. 349 PrimeChlSrvTime: Service time on the working scan channel. This 350 segment is invalid(set to 0) when AP oper mode is set to 2. The 351 maximum value of this segment is 10000, the minimum value of this 352 segment is 5000, the default value is 5000. 354 On Channle ScanTime: The scan time of the working channel. When the 355 AP oper mode is set to 2, this segment is invalid(set to 0). The 356 maximum value of thi segment is 120, the minimum value of this 357 segment is 60, the default value is 60. 359 L=1: Open Load Balance Scan. D=1: Open Rogue AP detection scan. 360 Flag: Bitmap, resered for furture use. 362 The definition of the Channel Bind TLV is as follows: 364 0 1 2 3 365 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 1 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 367 | Element ID | Length | 368 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 369 |Radio ID | Flag | 370 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 371 | Max Cycles | Reserved | Channel Count | 372 +---------------------------------------------------------------+ 373 | Scan Channel Set... | 374 +---------------------------------------------------------------+ 376 Element ID: TBD. Length>=12 378 Flag: bitmap, reserved. 380 Scan Src: the trigger of the scan event. not defined in this version 381 of the document. set to 0. 383 Device Type: the scope of the scan. not defined is this version of 384 the document. set to 0. 386 Max Cycles: Scan repeat times. 255 means continuous scan. 388 Scan Channel Set: the channle information. the format is as follows: 390 0 1 2 3 391 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 1 392 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 | Channel ID | Flag | 394 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 395 Channel ID: the channel ID of the channel which will be scanned. 397 Flag: bitmap, reserved for future use. 399 The channle scan procedure: 401 The AP has two work mode: the first one is normal mode. In this 402 mode, the AP can provide service for the STA access and scan the 403 channel at the same time. Whether the AP will scan the channel is 404 determined by the Max Cycles segment in the Channle Bind TLV. When 405 this segment is set to 0, the AP will not scan the channle. If this 406 segment is set to 255, the AP will continuous scan the channel. The 407 type of the scan is determined by the Sacn Type segment. In the 408 passive scan type, the AP monitor the airinterface, based on the 409 received beacon frame to determine the nearby APs. In the active 410 scan type, the AP will send probe message and receive the probe 411 response message. In the normal scan mode, the AP will use 3 412 parameters: PrimeChlSrvTime, OnChannelScanTIme, OffChannelScnTIme. 413 The AP will provide access service for the STAs for PrimeChlSrvTime 414 duration and then start to scan the channel for On Channel ScnTime 415 duration. Back to the working channel, provide STA access service 416 for PrimeChlSrvTime, then leave the working channel, start to scan 417 the next channel for Off Channel ScanTime duration. This process 418 will be repeated until all the channel is scanned. 420 When the AP work in the scan only mode, there is no difference 421 between the working channel and scan channel. Every channel's scan 422 duration will be OffChannelScnTime and the PrimeChlSrvTime and 423 OnChannelScanTime is set to 0. 425 Scan Report. THe AP send the scan report to the AC through WTP Event 426 Request message. The information element that used to carry the scan 427 report is Channel Scan Report TLV and Neighbor AP Report TLV. The 428 definition of the Channel Scan Report TLV is as follows: 430 0 1 2 3 431 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 1 432 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 433 | Element ID | Length | 434 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 435 | Radio ID | Report Count | Channel Scan Report | 436 +---------------------------------------------------------------+ 438 Element ID: 133; Length: >= 20. 440 Report Count: the channle number will be reported. The definition of 441 the channel scan report is as follows: 443 0 1 2 3 444 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 1 445 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 446 | Channel Number | Radar Statistics | Mean | 447 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 448 | Time | Mean RSSI | Screen Packet Count | 449 +---------------------------------------------------------------+ 450 | NeighborCount| Mean Noise | Interference | Self Tx Occp | 451 +---------------------------------------------------------------+ 452 | SelfStaOccp | Unknown Occp | CRC Err Cnt | Decrypt Err Cnt | 453 +---------------------------------------------------------------+ 454 |Phy Err Cnt | Retrans Cnt | 455 +-----------------------------+ 457 Channel Number: The channel number. 459 Radar Statistics: Whether detect radar signal in this channel. 0x00: 460 detect radar signal. 0x01: no radar signal is detected. 462 Mean Time: Channel measurement duration. 464 Mean RSSI: The signal strength of the scanned channel. 466 Screen Packet Count: Received packet number. 468 Neighbor Count: The neighbor number of this channel. 470 Mean Noise: the average noise on this channel. 472 Interference: The interference of the channel. 474 Self Tx Occp: The time duration for transmission. 476 Unknown Occp: TBD. 478 CRC Err Cnt: CRC err packet number. 480 Decrypt Err Cnt: Decryption err packet number. 482 Phy Err Cnt: Physical err packet number. 484 Retrans Cnt: Retransmission packet number. 486 The definition of neighbor AP report TLV is as follows: 488 0 1 2 3 489 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 1 490 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 491 | Element ID | Length | 492 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 493 | Radio ID | Reserved | Number of Neighbor Report | 494 +---------------------------------------------------------------+ 495 | Neighbor Infor... | 496 +---------------------------------------------------------------+ 498 Element ID: 134; Length:>=16 500 The definition of Neighbor info is as follows: 502 0 1 2 3 503 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 1 504 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 505 | BSSID | 506 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 507 | BSSID | Channel Number | 508 +---------------------------------------------------------------+ 509 | 2rd Offset | Mean RSSI | Sta Intf | AP Intf | 510 +---------------------------------------------------------------+ 512 BSSID: The BSSID of this neighbor channel. 514 Channel Number: The channel number of this neighbor channel. 516 2rd channel offset: TBD. 518 Mean RSSI: The average signal strength of the channel. 520 Sta Intf: TBD. 522 AP Intf: TBD. 524 6. Security Considerations 526 TBD 528 7. IANA Considerations 530 None 532 8. Contributors 534 This draft is a joint effort from the following contributors: 536 Gang Chen: China Mobile chengang@chinamobile.com 538 Naibao Zhou: China Mobile zhounaibao@chinamobile.com 540 Chunju Shao: China Mobile shaochunju@chinamobile.com 542 Hao Wang: Huawei3Come hwang@h3c.com 544 Yakun Liu: AUTELAN liuyk@autelan.com 546 Xiaobo Zhang: GBCOM 548 Xiaolong Yu: Ruijie Networks 550 Song zhao: ZhiDaKang Communications 552 Yiwen Mo: ZhongTai Networks 554 9. Acknowledgements 556 The authors would like to thanks Ronald Bonica and Benoit Claise for 557 their usefull suggestions. 559 10. Normative References 561 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 562 Requirement Levels", BCP 14, RFC 2119, March 1997. 564 [RFC4564] Govindan, S., Cheng, H., Yao, ZH., Zhou, WH., and L. Yang, 565 "Objectives for Control and Provisioning of Wireless 566 Access Points (CAPWAP)", RFC 4564, July 2006. 568 [RFC5415] Calhoun, P., Montemurro, M., and D. Stanley, "Control And 569 Provisioning of Wireless Access Points (CAPWAP) Protocol 570 Specification", RFC 5415, March 2009. 572 Authors' Addresses 574 Yifan Chen 575 China Mobile 576 No.32 Xuanwumen West Street 577 Beijing 100053 578 China 580 Email: chenyifan@chinamobile.com 582 Dapeng Liu 583 China Mobile 584 No.32 Xuanwumen West Street 585 Beijing 100053 586 China 588 Email: liudapeng@chinamobile.com 590 Hui Deng 591 China Mobile 592 No.32 Xuanwumen West Street 593 Beijing 100053 594 China 596 Email: denghui@chinamobile.com 598 Lei Zhu 599 Huawei 600 No. 156, Shi-Chuang-Ke-Ji-Shi-Fan-Yuan Beiqing Road, Haidian District 601 Beijing 100095 602 China 604 Email: lei.zhu@huawei.com