1. Notes on Interworking with External Networks
July 2010
doc.: IEEE /1272r3
Aug 2010
Notes on Interworking with External Networks
Date:
Authors:
George Bumiller, Research In Motion
George Bumiller, Research In Motion

2. July 2010
doc.: IEEE /1272r3
Aug 2010
Abstract
This presentation provides an overview of the main features included in the current draft D_10.0 of Interworking with External Networks, together with the approved comment resolutions from 11-10/0766r4 Extracts from the draft are provided, to stimulate discussion, comment and suggestions from other SDOs. The draft has been proceeding through Sponsor Ballot status, indicating a reasonable degree of maturity. Note that it is only a draft, not a standard, and may change.
George Bumiller, Research In Motion
George Bumiller, Research In Motion

3. Agenda IEEE 802.11 IEEE 802.11u IEEE 802.11u Features
July 2010
doc.: IEEE /1272r3
Aug 2010
Agenda
IEEE
IEEE u
IEEE u Features
Network Discovery and Selection
Emergency Services
QoS Map distribution
SSPN Interface service between the AP and the SSPN
Comments and Suggestions Requested
References
Extracts from IEEE u draft D_10.0
George Bumiller, Research In Motion
George Bumiller, Research In Motion

4. Aug 2010
IEEE
IEEE is (together with recently-standardized amendments) the current standard. IEEE p, Wireless Access in Vehicular Environments is the latest amendment standardized. TGu, Interworking With External Networks is the initiative which supports and extends the current use of WLAN for other Wide Area Networks (WANs). It has progressed through letter ballot, and is now in Sponsor Ballot (the final balloting stage) at draft D_10.0.
George Bumiller, Research In Motion

5. IEEE 802.11 – Current and Draft Amendments
Aug 2010
IEEE – Current and Draft Amendments
Today’s standard: IEEE k, r, y, n, p.
Single document in process.
Today’s drafts in Sponsor Ballot: u, v, and z.
Note that the draft amendments refer to items being added by other draft amendments. These are based on an expected approval sequence, and will be adjusted if approvals are in a different sequence.
George Bumiller, Research In Motion

6. Sequencing of Draft Amendments
Aug 2010
Sequencing of Draft Amendments
There are three draft amendments before this draft, 11u. There are dependencies, with some draft amendments making use of certain functions defined in earlier draft amendments. Therefore, for a better understanding of this (u) draft, one needs to refer to those functions in the draft amendments scheduled for standardization before 11u. The sequence is: z AP-Independent Direct Link Setup v Wireless Network Management u Interworking with External Networks
George Bumiller, Research In Motion

7. Steps in IEEE 802.11u Study Group Technical Group, TGu
Aug 2010
Steps in IEEE u
Study Group
Technical Group, TGu
Develop Requirements
Develop Draft Specification, then start balloting
Ballot Draft (until no required technical comments remain)
Sponsor Ballot (IEEE-wide balloting) current status
Adoption as Approved Amendment (& published)
Integration into IEEE xx
George Bumiller, Research In Motion

8. Interworking with External Networks, IEEE 802.11u
Aug 2010
Interworking with External Networks, IEEE u
This adds and enhances four major features:
Network Discovery and Selection,
Emergency Services ,
QoS Map distribution,
SSPN Interface service between the AP and the SSPN.
The discovery of these services is enabled through advertisement services, providing interchange of data between the STA (mobile) and the AP, without need for the STA to be associated.
The AP is able to provide generic container data [provided by each of the WAN technologies], to assist the STA in its interworking.
George Bumiller, Research In Motion

9. Abbreviations and Definitions
Aug 2010
Abbreviations and Definitions
ANQP: Access Network Query Protocol Non-AP STA – non-Access Point Station, i.e. a mobile unit GAS: The Access Network Query protocol transported by GAS Public Action frames [does not require association with the AP] HESSID (homogenous ESS Identifier): A collection of BSSs, within the same extended service set (ESS), in which the SSPN or other external network reachable at one BSS, is reachable at all of them. OI: organization identifier [may be used to identify SSPNs, aggregators and other operating organizations.] SSPN: subscription service provider network
George Bumiller, Research In Motion

10. Network Discovery and Selection
Aug 2010
Network Discovery and Selection
Previously
Use SSID, associate. Destination reachable?
Associate with next AP,…(if the first one unusable)
Continue until usable AP reached
With u
Check APs concurrently without association
Up to three OIs in beacon or probe response
Result
Faster discovery and selection, compared to sequential association with APs
George Bumiller, Research In Motion

11. Network Discovery and Selection (Extract)
Aug 2010
Network Discovery and Selection (Extract)
• Discovery of suitable networks through the advertisement of access network type, roaming consortium and venue information, via management frames • Selection of a suitable IEEE infrastructure using advertisement services (e.g., ANQP or an IEEE Information Server) in the BSS or in an external network reachable via the BSS • Selection of an SSPN or External Network with its corresponding IEEE infrastructure
George Bumiller, Research In Motion

12. Advertisement Protocol ID definitions
Aug 2010
Advertisement Protocol ID definitions
Name
Access Network Query Protocol
Emergency Call information
Roaming Consortium information
Cellular Network information
NAI realm information
MIH Information Service
MIH Command and Event Services
Capability Discovery
Emergency Alert System (EAS)
Location-to-Service Translation Protocol
George Bumiller, Research In Motion

13. Aug 2010
Emergency Services
Provides method for unauthenticated users to access Emergency Services
Link level support
Requires higher layer application
Emergency Calls
Provides the local emergency call numbers
Emergency Alerts
Provides emergency alerts, with a unique hash so that STAs (mobiles) know when each alert is new
George Bumiller, Research In Motion

14. Aug 2010
QoS Mapping
For SSPNs and other external networks Re-maps the layer-3 service levels to a common over-the-air service level
George Bumiller, Research In Motion

15. SSPN Interface service
Aug 2010
SSPN Interface service
A service between the AP and the SSPN Supports service provisioning and transfer of user permissions from the SSPN to the AP The IEEE network interacts with the SSPN corresponding to the user of the non-AP STA either directly or via a roaming relationship.
George Bumiller, Research In Motion

16. Aug 2010
Use of HESSID
“… we recommended the use of the new parameter “HESSID”. We would just like to clarify that this an identifier of the network behind the layer 2 wireless route and that it should be used in conjunction with SSID, which is the existing WLAN radio access identifier. Both HESSID and SSID are therefore used together to discover a specific WLAN and its network attachment. If the HESSID parameter is not available in the WLAN hotspot, then the SSID is used only, as with current implementations.”
HESSID (homogenous ESS Identifier) A collection of BSSs, within the same extended service set (ESS), …
George Bumiller, Research In Motion

17. Interworking With External Networks
Aug 2010
Summary
Interworking With External Networks
Enables faster discovery and selection of WLANs
HESSID assists in the identification of WLANs
Generic Advertisement Service
Locally-stored data is accessible through native query protocol, e.g. provided for each WAN technology
IEEE (when available) may be accessed
Support for Emergency Services (calls and alerts)
QoS Map
George Bumiller, Research In Motion

18. Your Suggestions, Comments and Questions are requested
Aug 2010
Your Suggestions, Comments and Questions are requested
Bruce Kraemer
IEEE Working Group Chair
Stephen McCann
IEEE Secretary & IEEE Task Group u Chair
George Bumiller, Research In Motion

19. References IEEE 802.11u Draft 10.0 (July 2010)
Aug 2010
References
IEEE u Draft 10.0 (July 2010)
Please note that IEEE u Draft 10.0 (June 2009) is available for purchase at the IEEE shop:
Then go to Individual Standards: Draft Standards (center column)
Enter “P802.11u” in the right-hand search box.
IEEE (the current base standard)
Please note that IEEE standards are available free six months after publication.
Note that amendments k, r, y, n, p are now standards. These amendments are now being integrated into a single document, which will become IEEE
P802.11u_D10.0 2nd recirc comments spreadsheet
These comments have been used to update the extracts in this presentation.
u-d10-0-2nd-recirc-comments-spreadsheet.xls
Freely available at
George Bumiller, Research In Motion

20. Aug 2010
IEEE u D_10.0 extracts
Overview (1 & 2) Generic Advertisement Service Access Network Type Advertisement Protocol ID definitions Access Network Query Protocol information ID definitions Interworking with External Network Procedures (1, 2 & 3) Interactions with SSPN
George Bumiller, Research In Motion

21. Overview - 1 (Extract) Aug 2010
5.4.8 Interworking with External Networks
The Interworking Service allows non-AP STAs to access services provided by an external network according to the subscription or other characteristics of that external network. An IEEE non-AP STA may have a subscription relationship with an external network, e.g., with an SSPN.
An overview of the interworking functions addressed in this standard is provided below:
—Network Discovery and Selection
• Discovery of suitable networks through the advertisement of access network type, roaming consortium and venue information, via management frames
• Selection of a suitable IEEE infrastructure using advertisement services (e.g., ANQP or an IEEE Information Server) in the BSS or in an external network reachable via the BSS
• Selection of an SSPN or External Network with its corresponding IEEE infrastructure
—Emergency Services
• Emergency Call and Network Alert support at the link level
—QoS Map distribution
—SSPN Interface service between the AP and the SSPN
George Bumiller, Research In Motion

22. Overview – 2 (Extract) Aug 2010
The Generic Advertisement Service (GAS), described in 5.9, can be used by a STA to provide support for the network selection process and as a conduit for communication by a non-AP STA with other information resources in a network before joining the wireless LAN.
The Interworking Service supports Emergency Services (ES) by providing methods for users to access emergency services via the IEEE infrastructure, advertising that emergency services are supported (see ) and identifying that a traffic stream is used for emergency services.
The Interworking Service provides QoS mapping for SSPNs and other external networks. Since each SSPN or other external network may have its own layer-3 end-to-end packet marking practice (e.g., DSCP usage conventions), a means to re-map the layer-3 service levels to a common over-the-air service level is necessary. The QoS Map service provides STAs a mapping of network-layer QoS packet marking to over-the-air QoS frame marking (i.e., user priority).
The SSPN Interface service supports service provisioning and transfer of user permissions from the SSPN to the AP. The method and protocol by which these permissions are transferred from the SSPN are out of scope of this standard.
George Bumiller, Research In Motion

23. Aug 2010
Generic Advertisement Service - 1 [Obtaining information from the AP without Association] (Extract)
5.9 Generic Advertisement Service The Generic Advertisement Service (GAS) provides functionality that enables STAs to discover the availability of information related to desired network services, e.g., information about services such as provided in an IBSS, local access services, available Subscription Service Providers (SSP) and/or SSPNs or other external networks. GAS uses a generic container to advertise network services' information over an IEEE network. Public Action frames are used to transport this information. While the specification of network services information is out of scope of IEEE , in an Infrastructure BSS there is a need for STAs to query for information on network services provided by SSPNs or other external networks beyond an AP, before they associate to the wireless LAN. The exchange of information may also be performed after associating to the BSS. In an IBSS, GAS functionality enables a STA to access the availability and information related to desired services provided by other STAs in the IBSS. Exchange of information using GAS may be performed either prior to joining an IBSS or after joining the IBSS.
George Bumiller, Research In Motion

24. Aug 2010
Generic Advertisement Service - 2 [Obtaining information from the AP without Association] (Extract)
There are a number of reasons why providing information to a STA in a pre-associated state is beneficial:
It supports more informed decision making about an IEEE infrastructure with which to associate. This is generally more efficient than requiring a non-AP STA to associate with an AP before discovering the information and then deciding whether or not to stay associated.
It is possible for the non-AP STA to query multiple networks in parallel.
The non-AP STA can discover information about APs that are not part of the same administrative group as the AP with which it is associated, supporting the selection of an AP belonging to a differ­ent IEEE infrastructure that has an appropriate SSP roaming agreement in place.
George Bumiller, Research In Motion

25. Table 7-43bk— Access Network Type (Extract)
Aug 2010
Table 7-43bk— Access Network Type (Extract)
Access Network Type
Meaning
Description
Private network
Non-authorized users are not permitted on this network. Examples of this network type are home networks and enterprise networks, which may employ user accounts. Private networks do not necessarily employ encryption. 1
Private network with guest access
Private network but guest accounts are available. Example of this network type is enterprise network offering access to guest users 2
Chargeable public net- work
The network is accessible to anyone, however, access to the net-work requires payment. Further information on types of charges may be available through other methods (e.g., , http/https redirect or DNS redirection). Examples of this network type is a hotspot in a coffee shop offering internet access on a subscription basis or a hotel offering in-room internet access service for a fee. 3
Free public network
The network is accessible to anyone and no charges apply for the network use. An example of this network type is an airport hotspot or municipal network providing free service. 4
Personal Device Net- work
A network of personal devices. An example of this type of network is a camera attaching to a printer, thereby forming a network for the purpose of printing pictures. 5
Emergency Services Only Network
A network dedicated and limited to accessing emergency services.
6 to 13
Reserved 14
Test or experimental
The network is used for test or experimental purposes only. 15
Wildcard
Wildcard network type
George Bumiller, Research In Motion

26. Table 7-43bm—Advertisement Protocol ID definitions (Extract)
Aug 2010
Table 7-43bm—Advertisement Protocol ID definitions (Extract)
Name
Value
Access Network Query Protocol
MIH Information Service 1
MIH Command and Event Services Capability Discovery 2
Emergency Alert System (EAS) 3
Reserved
4-220
Vendor Specific
221
George Bumiller, Research In Motion

27. ANQP Info Element (clause)
Aug 2010
Table 7-43bo—Access Network Query Protocol info ID definitions (Extract)
Info Name
Info ID
ANQP Info Element (clause)
Reserved
0-255
n/a
ANQP Capability List
256
Venue Name information
257
Emergency Call Number information
258
Network Authentication Type information
259
Roaming Consortium List
260
IP Address Type Availability information
261
NAI Realm List
262
3GPP Cellular Network information
263
AP Geo Location
264
AP Civic Location
265
AP Location Public Identifier URI
266
Domain Name List
267
Emergency Alert Identifier URI
268
TDLS Discovery
269
270–
Access Network Query Protocol vendor-specific list
56797
56798 –
George Bumiller, Research In Motion

28. Interworking with External Network Procedures - 1 (Extract)
Aug 2010
Interworking with External Network Procedures - 1 (Extract)
11.23 WLAN Interworking with External Networks Procedures General This subclause describes the actions and the procedures that provide interworking capabilities between infrastructure and external networks Interworking capabilities and information STAs indicate their support for Interworking Service by setting the dot11InterworkingServiceEnabled MIB variable to true. When dot11InterworkingServiceEnabled is true, APs include the Interworking element in Beacon and Probe Response frames and non-AP STAs include the Interworking element in Probe Request frames. When dot11InterworkingServiceEnabled. and dot11ExtendedChannelSwitchEnabled are both set to TRUE, the AP may provide its operating channel and regulatory class to an Interworked SSPN using the dot11RegulatoryClassesTable MIB entry. The Interworking information element contains signaling for Homogeneous ESSs. The HESSID is a 6 octet MAC address which identifies the homogeneous ESS. The HESSID value shall be identical to one of the BSSIDs in the homogeneous ESS. Thus, it is a globally unique identifier, which in conjunction with the SSID, may be used to provide network identification for an SSPN. NOTE—It is required by this standard that the HESSID field in the Interworking element is administered consistently across all BSSs in a homogeneous ESS. The Interworking information element also provides a Network Type value in Beacon and Probe Response frames to assist the non-AP STA with network discovery and selection.
George Bumiller, Research In Motion

29. Interworking with External Network Procedures - 2 (Extract)
Aug 2010
Interworking with External Network Procedures - 2 (Extract)
Interworking Procedures: Generic Advertisement Services This subclause describes the actions and procedures that are used to invoke Generic Advertisement Services (GAS). GAS may be used to enable network selection for STAs when dot11InterworkingServiceEnabled is true. GAS provides transport mechanisms for advertisement services while STAs are in the un-associated state as well as the associated state. This is accomplished via the use of Public Action management frames which are Class-1 frames. GAS messages shall be transmitted using individually-addressed Public Action frames. When Management Frame Protection is negotiated, stations shall use individually addressed Protect­ed Dual of Public Action frames instead of individually addressed Public Action frames. A GAS message exchange may take place between two STAs; one STA transmits a GAS Query Request and the other STA transmits the GAS Query Response as described in The Advertisement Protocol transported by the GAS is one of the query protocols in Table 7-43bl. GAS shall be supported by a STA when dot11InterworkingServiceEnabled is true. ANQP shall be supported by a STA when dot11InterworkingServiceEnabled is true. Other advertisement protocols shall be supported when the corresponding dot11GASAdvertisementID is present. STAs shall not transmit a GAS Query for any Advertisement Protocol unless that Advertisement Protocol ID is included in the Advertisement Protocol element in a Beacon or Probe response frame. The Advertisement Protocol element specifies the Advertisement Protocols that a STA may use to communicate with Advertise­ment Servers, which may be co-located with a STA or in an external network. The Advertisement Protocol identifies the query language used by the Advertisement Server. The GAS protocol, which is used to transport Queries and Query Responses, is transparent to the Advertisement Protocol.
George Bumiller, Research In Motion

30. Interworking with External Network Procedures - 3 (Extract)
Aug 2010
Interworking with External Network Procedures - 3 (Extract)
GAS Protocol
Presence of the Interworking element in Beacon or Probe Response frames indicates support for the GAS pro­tocol. Presence of the Advertisement Protocol element in Beacon or Probe Response frames indicates the Ad­vertisement Protocol IDs supported in the BSS or IBSS. A STA transmits a GAS Query using a GAS Initial Request frame and the responding STA provides the query response or information on how to receive the que­ry response in a GAS Initial Response frame. The GAS Query Response shall be delivered in a single GAS Initial Response frame or in one or more GAS Comeback Response frames; the GAS Query Response shall not be split between a GAS Initial Response frame and one or more GAS Comeback Response frames. The GAS message sequence diagrams are shown in Figures 11-17e, 11-17f and 11-17g.
George Bumiller, Research In Motion

31. Interactions with SSPN (Extract)
Aug 2010
Interactions with SSPN (Extract)
Interworking Procedures: Interactions with SSPN General Operation To provide SSPN Interface services, the IEEE network interacts with the SSPN corresponding to the user of the non-AP STA either directly or via a roaming relationship. As part of setting up the RSN security association, user policies are communicated to the AP. If dot11SSPNInterfaceEnabled is true, these permissions shall be stored in the AP's dot11InterworkingTableEntry for that STA. Thereafter, the AP shall use the dot11InterworkingTableEntry for controlling the service provision to that non-AP STA. User policies from the SSPN affect authentication, authorization, and admission control decisions at the AP. In addition, the AP collects statistics about the non-AP STA and reports the statistics to the SSPN when requested. The SSPN may also send service provision instructions to the AP, e.g., to terminate the connection to a non-AP STA. Non-AP STAs do not support the SSPN Interface. Network deployments typically provide that the AP and the server in the SSPN have a trustworthy channel that can be used to exchange information, without exposure to or influence by any intermediate parties. The establishment of this secure connection between the IEEE infrastructure and the SSPN is out of scope of this standard.
George Bumiller, Research In Motion

32. Your comments and suggestions are welcome and requested.
Aug 2010
Your comments and suggestions are welcome and requested.
End
George Bumiller, Research In Motion