《IEEE-802.11R-2008.pdf》由会员分享，可在线阅读，更多相关《IEEE-802.11R-2008.pdf（126页珍藏版）》请在三一文库上搜索。
1、IEEE Std 802.11r-2008 (Amendment to IEEE Std 802.11-2007 as amended by IEEE Std 802.11k-2008) 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 (M
2、AC) and Physical Layer (PHY) Specifications Amendment 2: Fast Basic Service Set (BSS) Transition IEEE 3 Park Avenue New York, NY 10016-5997, USA 15 July 2008 IEEE Computer Society Sponsored by the LAN/MAN Standards Committee 802.11r TM Copyright The Institute of Electrical and Electronics Engineers,
3、 Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under li
4、cense with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Std 802.11r-2008 (Amendment to IEEE Std 802.11-2007 as amended by IEEE Std 802.11k-2008) IEEE Standard for Information
5、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 Amendment 2: Fast Basic Service Set (BSS) Transition Sponsored by LAN/MAN Standa
6、rds Committee of the IEEE Computer Society Approved 9 May 2008 IEEE-SA Standards Board Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproductio
7、n or networking permitted without license from IHS -,-,- The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright 2008 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 15 July 2008. Printed in the U
8、nited States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Copyright The Institute of Electrical and Electronics Eng
9、ineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ivCopyright 2008 IEEE. All rights reserved. Introduction This amendment describes mecha
10、nisms that minimize the amount of time data connectivity is lost between the station (STA) and the distribution system (DS) during a basic service set (BSS) transition. The STA determines when to transition and to which access point (AP) to transition based on a number of factors, some of which may
11、be out of the scope of this standard. The following summarizes the typical behavior of the non-AP STA and AP when a transition occurs without fast BSS transition (FT) services: The STA uses scanning or neighbor reports to discover APs available for transition. The STA chooses a target AP and perform
12、s an IEEE 802.11 authentication exchange with that AP; typically this exchange will be an “open auth” exchange. During this time, the STA may still exchange data with the DS through its current AP. The STA sends a (Re)Association frame to establish a connection at the target AP. In a robust security
13、 network (RSN), the STA and the AP then generate and confirm matching temporal keys based on a preshared key (PSK) or an IEEE 802.1X authentication (which could be through an earlier preauthentication or key caching). In an RSN, the STA and AP install the keys and start to exchange data with the DS.
14、 For a quality of service (QoS) STA connected to a QoS AP, the STA may then request QoS resources by issuing one or more ADDTS (add traffic stream) requests. The FT mechanism allows a STA to establish security and/or QoS state at the target AP prior to or during reassociation, avoiding delays in con
15、necting to the DS after transition. The overall changes to the protocol do not introduce any new security vulnerabilities beyond the current IEEE 802.11 standard and its amendments. The FT mechanism preserves the behavior of legacy STAs and APs. The FT time is the total transition time that starts a
16、fter the receipt of the last acknowledged data frame sent within an originating BSS and ends after the receipt of the first acknowledged data frame sent within the destination BSS, while the non-AP STA transitions from one BSS to another using the FT mechanisms. This amendment addresses solutions to
17、 two classes of network infrastructures from a QoS perspective: one where the transition-enabled AP is willing to provision QoS resources at reassociation time; and another where the AP needs to reserve the network infrastructure resources before transitioning. This amendment does not specifically a
18、ddress the solution of when or where a STA will roam. Other tools give the STA information that could be used in making this decision. IEEE 802.11 enables the AP to convey a BSS Load information element in Probe Response and Beacon frames. The BSS Load information element has three fields that indic
19、ate the number of associated STAs, the channel utilization for the BSS, and the available admission capacity. These QoS BSS metrics give information on the APs ability to accept new QoS streams. IEEE 802.11 defines the neighbor reports, which can assist in optimizing scanning. This introduction is n
20、ot part of IEEE Std 802.11-2007, IEEE Standard for information technology Telecommunications and information exchange between systemsLocal and metropolitan area networks Specific requirementsPart 11: Wireless Medium Access Control (MAC) and Physical Layer (PHY) SpecificationsAmendment 2: Fast Basic
21、Service Set (BSS) Transition. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,-
22、Copyright 2008 IEEE. All rights reserved.v Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance with the provisions of this standard does not imply compliance to any applicable regulatory requirements. Implementers of the standa
23、rd are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that is not in compliance with applicable laws, and these documents may not be construed as doing so. Copyrights This document is copyrig
24、hted by the IEEE. It is made available for a wide variety of both public and private uses. These include both use, by reference, in laws and regulations, and use in private self-regulation, standardization, and the promotion of engineering practices and methods. By making this document available for
25、 use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to this document. Updating of IEEE documents Users of IEEE standards should be aware that these documents may be superseded at any time by the issuance of new editions or may be amended from ti
26、me to time through the issuance of amendments, corrigenda, or errata. An official IEEE document at any point in time consists of the current edition of the document together with any amendments, corrigenda, or errata then in effect. In order to determine whether a given document is the current editi
27、on and whether it has been amended through the issuance of amendments, corrigenda, or errata, visit the IEEE Standards Association website at http:/ ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE at the address listed previously. For more information about the IEEE Standards Association
28、or the IEEE standards development process, visit the IEEE-SA website at http:/standards.ieee.org. Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:/ standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for
29、 errata periodically. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights
30、. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE shall not be responsible for identifying patents or patent applications for which a license may be required to implement an IEEE standard or for co
31、nducting inquiries into the legal validity or scope of those patents that are brought to its attention. A patent holder or patent applicant has filed a statement of assurance that it will grant licenses under these rights without compensation or under reasonable rates and nondiscriminatory, reasonab
32、le terms and conditions to Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,- viC
33、opyright 2008 IEEE. All rights reserved. applicants desiring to obtain such licenses. The IEEE makes no representation as to the reasonableness of rates, terms, and conditions of the license agreements offered by patent holders or patent applicants. Further information may be obtained from the IEEE
34、Standards Department. Participants At the time this amendment was sent to sponsor ballot, the IEEE 802.11 Working Group had the following officers: Stuart J. Kerry, Chair Al Petrick, Vice Chair, Treasurer and Chair, Task Group mb Harry R. Worstell, Vice Chair Stephen McCann, Secretary and Chair, Pub
35、licity Standing Committee Teik-Kheong Tan, Chair, Wireless Next Generation Standing Committee Terry L. Cole, Technical Editor and Assigned Number Authority Richard H. Paine, Chair, Task Group k Bruce P. Kraemer, Chair, Task Group n and Co-Chair IMT-Advanced Ad hoc Committee Sheung Li, Vice Chair, Ta
36、sk Group n Lee Armstrong, Chair, Task Group p Donald E. Eastlake III, Chair, Task Group s Neeraj Sherma, Chair, Task Group T Stephen McCann, Chair, Task Group u Dorothy V. Stanley, Chair, Task Group v for CCMP, it is the PN and is stored in the first 6 octets. See Table 61.1 For WEP, the RSC value i
37、s set to 0 on transmit and is not used at the receiver. When sent by a non-AP STA, the R0KH-ID indicates the R0KH with which the S0KH negotiated the PMK-R0 it is using for this transition. When sent by an AP, the R0KH-ID indicates the R0KH that the S0KH will be using to generate a PMK-R0 security as
38、sociation. It is encoded following the conventions from 7.1.1. 7.3.2.49 Timeout Interval information element (TIE) The TIE specifies time intervals and timeouts. Figure 7-95o8 shows this information element. The Length field is set to 5. The Timeout Interval Type field contains one of the values fro
39、m Table 7-43h. The Timeout Interval Value field contains an unsigned 32-bit integer. It is encoded according to the conventions in 7.1.1. A reassociation deadline interval value of zero indicates no deadline exists. A key lifetime interval value of zero is reserved. 1Notes in text, tables, and figur
40、es of a standard are given for information only and do not contain requirements needed to implement the standard. Element IDLengthTimeout Interval TypeTimeout Interval Value Octets:1114 Figure 7-95o8TIE format Table 7-43hTimeout Interval Type field value Timeout interval typeMeaningUnits 0Reserved 1
41、Reassociation deadline intervalTime units (TUs) 2Key lifetime intervalSeconds 3255Reserved Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reprodu
42、ction or networking permitted without license from IHS -,-,- IEEE AMENDMENT 2: FAST BSS TRANSITION Std 802.11r-2008 Copyright 2008 IEEE. All rights reserved.17 7.3.2.50 RIC Data information element (RDIE) The RIC refers to a collection of information elements that are used to express a resource requ
43、est and to convey responses to the corresponding requests. A RIC is a sequence of one or more Resource Requests, or a sequence of one or more Resource Responses. Each Resource Request or Response consists of a RDIE, followed by one or more information elements that describe that resource. See 11A.11
44、 for examples and procedures. The RDIE format is shown in Figure 7-95o9. The Length field is set to 4. The RDIE Identifier field has an arbitrary 8-bit value, chosen by the resource requestor to uniquely identify the RDIE within the RIC. The Resource Descriptor Count field indicates the number of al
45、ternative Resource Descriptors that follow this RDIE. The Status Code field is used in Resource Responses to indicate the result of the request. Valid values for the Status Code field are given in 7.3.1.9. When an RDIE is included in a Resource Request, the Status Code field is set to 0 and ignored
46、upon receipt. 7.3.2.51 RIC Descriptor information element The RIC Descriptor information element is used with an RDIE during a fast BSS transition to negotiate resources that are not otherwise described by information elements. See 11A.11 for procedures for including this information element in a RI
47、C. Figure 7-95o10 shows the format of this information element. The Length field is set to the number of octets in this information element (variable). The Resource Type field contains one of the values given in Table 7-43i. Variable parameters contain any additional data based on the resource type.
48、 Element IDLengthRDIE IdentifierResource Descriptor CountStatus Code Octets:11112 Figure 7-95o9RDIE format Element IDLengthResource TypeVariable parameters Octets:111variable Figure 7-95o10RIC Descriptor information element format Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 08/04/2008 03:13:35 MDTNo reproduction or networking permitted without license from IHS -,-,