Notes on Interworking with External Networks

uptightexampleΔίκτυα και Επικοινωνίες

24 Οκτ 2013 (πριν από 3 χρόνια και 5 μήνες)

74 εμφανίσεις

doc.: IEEE 802.11
-
09/1272r2

Submission

Notes on Interworking with External Networks

Date:

2010 07 22


July 2010

George Bumiller, Research In Motion

Slide
1

Authors:

doc.: IEEE 802.11
-
09/1272r2

Submission

Abstract

This presentation provides an overview of the main
features included in the current draft D_10.0 of
Interworking with External Networks.

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.

July 2010

George Bumiller, Research In Motion

Slide
2

doc.: IEEE 802.11
-
09/1272r2

Submission

Agenda

IEEE 802.11

IEEE 802.11u

IEEE 802.11u 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 802.11u draft D_10.0


July 2010

George Bumiller, Research In Motion

Slide
3

doc.: IEEE 802.11
-
09/1272r2

Submission

IEEE 802.11

IEEE 802.11
-
2007

is (together with recently
-
standardized
amendments) the current standard.

IEEE 802.11p, 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.


July 2010

George Bumiller, Research In Motion

Slide
4

doc.: IEEE 802.11
-
09/1272r2

Submission

IEEE 802.11


Current and Draft
Amendments


Today’s standard: IEEE 802.11
-
2007 +
802.11 k, r, y, n, p.



Single document in process.



Today’s drafts in Sponsor Ballot:


802.11 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.

July 2010

George Bumiller, Research In Motion

Slide
5

doc.: IEEE 802.11
-
09/1272r2

Submission

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


July 2010

George Bumiller, Research In Motion

Slide
6

doc.: IEEE 802.11
-
09/1272r2

Submission

Steps in IEEE 802.11u


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 802.11
-
20xx


July 2010

George Bumiller, Research In Motion

Slide
7

doc.: IEEE 802.11
-
09/1272r2

Submission

Interworking with External Networks,

IEEE 802.11u

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.


July 2010

George Bumiller, Research In Motion

Slide
8

doc.: IEEE 802.11
-
09/1272r2

Submission

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


July 2010

George Bumiller, Research In Motion

Slide
9

doc.: IEEE 802.11
-
09/1272r2

Submission

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 802.11u


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


July 2010

George Bumiller, Research In Motion

Slide
10

doc.: IEEE 802.11
-
09/1272r2

Submission

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 802.11 infrastructure using
advertisement services (e.g., ANQP or an IEEE 802.21
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 802.11 infrastructure


July 2010

George Bumiller, Research In Motion

Slide
11

doc.: IEEE 802.11
-
09/1272r2

Submission

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


July 2010

George Bumiller, Research In Motion

Slide
12

doc.: IEEE 802.11
-
09/1272r2

Submission

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


July 2010

George Bumiller, Research In Motion

Slide
13

doc.: IEEE 802.11
-
09/1272r2

Submission

QoS Mapping

For SSPNs and other external networks


Re
-
maps the layer
-
3 service levels to a common over
-
the
-
air service level


July 2010

George Bumiller, Research In Motion

Slide
14

doc.: IEEE 802.11
-
09/1272r2

Submission

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 802.11 network interacts with the SSPN
corresponding to the user of the non
-
AP STA either
directly or via a roaming relationship.


July 2010

George Bumiller, Research In Motion

Slide
15

doc.: IEEE 802.11
-
09/1272r2

Submission

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), …


July 2010

George Bumiller, Research In Motion

Slide
16

doc.: IEEE 802.11
-
09/1272r2

Submission

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 802.21 (when available) may be accessed


Support for Emergency Services (calls and alerts)


QoS Map



July 2010

George Bumiller, Research In Motion

Slide
17

doc.: IEEE 802.11
-
09/1272r2

Submission

Your Suggestions, Comments and
Questions are requested

Bruce Kraemer

IEEE 802.11 Working Group Chair

bkraemer@marvell.com

+1 321 427 4098


Stephen McCann

IEEE 802.11 Secretary & IEEE 802.11 Task Group u Chair

smccann@rim.com

+44 1753 667099


July 2010

George Bumiller, Research In Motion

Slide
18

doc.: IEEE 802.11
-
09/1272r2

Submission

References

IEEE 802.11u Draft 10.0 (July 2010)

Please note that IEEE 802.11u Draft 10.0 (June 2009) is available for purchase at the
IEEE shop:

https://sbwsweb.ieee.org/ecustomercme_enu/start.swe?SWECmd=GotoView&SW
EView=Catalog+View+(eSales)_Standards_IEEE&mem_type=Customer&SW
EHo=sbwsweb.ieee.org&SWETS=1192713657

Then go to Individual Standards: Draft Standards (center column)

Enter “P802.11u” in the right
-
hand search box.


IEEE 802.11
-
2007
(the current base standard)

Please note that IEEE 802.11 standards are available free six months after publication.

http://standards.ieee.org/getieee802/802.11.html

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 802.11
-
2010


P802.11u_D10.0 2nd recirc comments spreadsheet

These comments have been used to update the extracts in this presentation.

11
-
10
-
0766
-
04
-
000u
-
d10
-
0
-
2nd
-
recirc
-
comments
-
spreadsheet.xls

Freely available at
https://mentor.ieee.org/802.11/documents



July 2010

George Bumiller, Research In Motion

Slide
19

doc.: IEEE 802.11
-
09/1272r2

Submission

IEEE 802.11u 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


July 2010

George Bumiller, Research In Motion

Slide
20

doc.: IEEE 802.11
-
09/1272r2

Submission

Overview
-

1

(Extract)

July 2010

George Bumiller, Research In Motion

Slide
21

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 802.11 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 802.11 infrastructure using advertisement services (e.g.,
ANQP or an IEEE 802.21 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 802.11
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


doc.: IEEE 802.11
-
09/1272r2

Submission

Overview


2

(Extract)


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 802.11 infrastructure,
advertising that emergency services are supported (see 11.23.6) 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.


July 2010

George Bumiller, Research In Motion

Slide
22

doc.: IEEE 802.11
-
09/1272r2

Submission

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
802.11 network. Public Action frames are used to transport this information.

While the specification of network services information is out of scope of IEEE 802.11,
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.


July 2010

George Bumiller, Research In Motion

Slide
23

doc.: IEEE 802.11
-
09/1272r2

Submission

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 802.11 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 differ
ent IEEE 802.11 infrastructure that has an appropriate
SSP roaming agreement in place.


July 2010

George Bumiller, Research In Motion

Slide
24

doc.: IEEE 802.11
-
09/1272r2

Submission

Table 7
-
43bk


Access Network Type

(Extract)

Access
Network Type

Meaning

Description

0

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.,
802.21, 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

Reserved

14

Test or experimental

The network is used for test or experimental purposes only.

15

Wildcard

Wildcard network type

July 2010

George Bumiller, Research In Motion

Slide
25

doc.: IEEE 802.11
-
09/1272r2

Submission

Table 7
-
43bm

Advertisement Protocol ID definitions

(Extract)

July 2010

George Bumiller, Research In Motion

Slide
26

Name

Value

Access Network Query Protocol

0

MIH Information Service

1

MIH Command and Event Services Capability
Discovery

2

Emergency Alert System (EAS)

3

Reserved

4
-
220

Vendor Specific

221

Reserved

222
-
255

doc.: IEEE 802.11
-
09/1272r2

Submission

Table 7
-
43bo

Access Network Query Protocol info ID definitions

(Extract)

July 2010

George Bumiller, Research In Motion

Slide
27

Info Name

Info ID

ANQP Info
Element (clause)

Reserved

0
-
255

n/a

ANQP Capability List

256

7.3.4.2

Venue Name information

257

7.3.4.3

Emergency Call Number information

258

7.3.4.4

Network Authentication Type information

259

7.3.4.5

Roaming Consortium List

260

7.3.4.6

IP Address Type Availability information

261

7.3.4.8

NAI Realm List

262

7.3.4.9

3GPP Cellular Network information

263

7.3.4.10

AP Geo Location

264

7.3.4.11

AP Civic Location

265


7.3.4.12

AP Location Public Identifier URI

266


7.3.4.13

Domain Name List

267

7.3.4.14

Emergency Alert Identifier URI

268

7.3.4.15

TDLS Discovery

269

7.3.4.16

Reserved

270


56796

n/a

Access Network Query Protocol vendor
-
specific list

56797

7.3.4.7

Reserved

56798


65535

n/a

doc.: IEEE 802.11
-
09/1272r2

Submission

Interworking with External Network Procedures
-

1

(Extract)

11.23 WLAN Interworking with External Networks Procedures

11.23.1 General

This
subclause

describes the actions and the procedures that provide interworking capabilities between
802.11 infrastructure and external networks.

11.23.2 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.



July 2010

George Bumiller, Research In Motion

Slide
28

doc.: IEEE 802.11
-
09/1272r2

Submission

Interworking with External Network Procedures
-

2

(Extract)

11.23.3 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 Protect
ed 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 11.23.3.1. 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 Advertise
ment 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.


July 2010

George Bumiller, Research In Motion

Slide
29

doc.: IEEE 802.11
-
09/1272r2

Submission

Interworking with External Network Procedures
-

3

(Extract)

11.23.3.1 GAS Protocol

Presence of the Interworking element in Beacon or Probe Response frames indicates support for the GAS
pro
tocol. Presence of the Advertisement Protocol element in Beacon or Probe Response frames indicates
the Ad
vertisement 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 que
ry 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.


July 2010

George Bumiller, Research In Motion

Slide
30

doc.: IEEE 802.11
-
09/1272r2

Submission

Interactions with SSPN

(Extract)


11.23.4 Interworking Procedures: Interactions with SSPN

11.23.4.1 General Operation

To provide SSPN Interface services, the IEEE 802.11 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 802.11 infrastructure and the SSPN is out of scope of this standard.

July 2010

George Bumiller, Research In Motion

Slide
31

doc.: IEEE 802.11
-
09/1272r2

Submission


Your comments and suggestions are
welcome and requested.



End

July 2010

George Bumiller, Research In Motion

Slide
32