Transcript 11-13-1403-00-00aq-service-discovery-architecture-for-tgaq.ppt

Nov 2013
doc.: IEEE 802.11-13/1403r0
Service discovery architecture for TGaq
Date: 2013-11-05
Authors:
Name
Company
Address
Phone
email
Ping FANG
Huawei Technologies
Bldg. 7, Vision Software Park,
Road Gaoxin South 9, Nanshan,
Shenzhen, Guangdong, China,
518057
+86755 36839346
[email protected]
Ji CHEN
Huawei Technologies
Dapeng LIU
CMCC
Submission
[email protected]
Beijing, China
Slide 1
+86
13911788933
[email protected]
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Abstract
This document presents a service architecture for TGaq.
Service indication from AP, network discovery and detailed
service information query are described. Possible options and
issues are further discussed.
Submission
Slide 2
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Background
In 13/501r0, a architecture with service registration and service discovery is
registered. Per the meeting discussion, the registration can be done in MAC
layer or upper layer after association.
In 13/796r0, the procedure on how a STA discovers necessary service
information before association is described with a high level 2-step service
discovery procedure proposed.
In 13/796r1, more details on service indication are further discussed.
In 13/893r0, different service hash values proposed to be carried in service
discovery request and response with public action frame for privacy and
security
Submission
Slide 3
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Overall picture of 11aq
Submission
Slide 4
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Service Indication from AP
•
Option 1 : new Service Indication IE in Beacon/ Probe Response
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–
•
Option 2: new Public Action frame
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–
•
Carried in Beacon or Probe Response, no extra overhead
Good for passive scanning to indicate which services are provided or not
Extra load for AP to broadcast besides Beacon
STA doesn’t know when to receive, broadcast periodically
Assumption:
–
–
–
Submission
Proxy in AP caches general service information
Good for scenarios when lots of STA queries
Good to indicate what kind of services are provided or not
Slide 5
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Service Indication IE
•
•
Service Indication IE in Beacon/ Probe Response
Element ID
Length
Service indication bitmap
1 octet
1 octet
TBD octet
Service Indication Bitmap
–
–
Protocol Part: fixed bits to indicate protocols for services
Service Information Part: Bits used to indicate available services, each bit corresponds
to a service/services with hash value
Part 1: Protocol
Part 2: Service Information
UPnP
Bonjour
…
…
1
0
0
…
Bit 1
Bit 2
Bit 3
1
1
0
0
0
…
Hash(“UPnP:Printer”), then
set bit 1 value to be 1.
Submission
Slide 6
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
General Service Query
•
General Service Query
–
–
•
Option 1 : Combine with AP/Network discovery
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–
•
To decide whether a service can be provide via AP
Query and response can be relatively shorter
Carry service hash IE in Probe Request/Response
Different Service hash values can be carried in Probe request/response for privacy
Option 2: New Public Action frame [4]
–
–
Carry service hash values in PAM request/response
Different Service hash values be in Probe request/response for privacy
Option 1
Submission
Option 2
Slide 7
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Public Action Frame vs. Service IE
•
•
•
Option 1: Service IE in Probe Req/Resp
Element ID
Length
Service Hash Value
Service Capability
1 octet
1 octet
6 octets
0 or variable
Option 2:New Public Action Frame
MAC
Header
Catego
ry(=4)
Public
Action
Length
Service Hash Value
Service Capability
28 octet
1 octet
1octet
1 octet
6 octets
0 or variable
Option1 vs. option 2
Features
Option 1
Option 2
Help to reduce Probe Response from Legacy APs
No
Yes
Overhead
Submission
Almost same
Slide 8
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Detailed Service Query
•
Detailed Service Query (Different from general query)
–
–
Can provide detailed service information
The query response can be much bigger than that of general query
•
Option 1 : GAS mechanism for further information query
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Mechanism similar to ANQP as carried in GAS
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Option 2: new PAM (public action frame)[5]
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Carry detailed service query information in PAM between STA and AP
AP may forward the query to backhaul or associated STAs for further detailed information
Option 1
Submission
Option 2
Slide 9
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
New protocol in GAS vs. new Public Action Frame
•
•
•
Option 1: New advertisement protocol ID in GAS
MAC
Header
Categor
y(=4)
Public
Dialog
Action (=10) Token
Advertisement
Protocol element
28 octet
1 octet
1octet
variable
1 octet
Query Request
length
2
Query
variable
Option 2: new Public Action Frame
MAC
Header
Categor
y(=4)
Public
Action
Dialog
Token
Query Request
Length
28 octet
1 octet
1octet
1 octet
2
Query
variable
New advertisement protocol vs. new Public Action Frame
Features
Option 1
Option 2
Help to reduce queries
No (for unicast)
Yes (could be multicast)
Overhead
more
less
Submission
Slide 10
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Discussion on Practice
•
Service bitmap
–
–
•
For scenario with lots of STAs queries, service bitmap can help to reduce STAs’ queries
with passive scanning
When the number of services provided by AP is far less than the length of bitmap, the
bitmap can provide useful information to indicate which services are not provided
General service query vs. detailed service query
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–
Submission
When there are quite some APs and STAs around, general service query should be used
first to reduce channel time
For sparse environment, detailed service query can be used directly to query for detailed
service information
Slide 11
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Summary
•
•
•
•
Overall picture for TGaq is recaptured with service indication from AP,
general service query and detailed service query
Service bitmap IE in Beacon/Probe Resp for indication from AP
New Public Action frame carries different service hash values in general
service query/response
New Public Action frame carries detailed service query or response of
upper layer for detailed service query
Submission
Slide 12
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
References
1.
2.
3.
4.
5.
IEEE Std 802.11™-2012
11-13-0057-02-00aq-design-options
11-13-0501-00-00aq-service-registration-of-sta-to-an-ap
11-13-0893-00-00aq-service-discovery-proposal
11-13-0788-01-00aq-transaction-protocol
Submission
Slide 13
Ping FANG, Huawei
Nov 2013
•
Service Indication Performance Analysis
Assumption
–
–
–
•
doc.: IEEE 802.11-13/1403r0
Number of total service number:
Length of Service Hash bitmap:
Number of services supported by AP:
k = 5000
m= 128 bit
n = 16, 32, 48, 64, 80
Algorithm
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–
–
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Percentage of
no service
Service names are randomly generated with alphabets , digits and phonetic symbols
Services supported by AP are randomly chosen from 5000 services
Service hash values are calculated with SHA256, and then mod(128) to set a corresponding bit
in bitmap
Bit value 0 indicate there are no corresponding services
The result is to indicate how many percent of services are not supported by the AP, with the
128 bit service indication bitmap and given the n kind of services supported by the AP
1.0000
0.8807
0.8000
0.7707
0.6785
0.6000
0.5911
0.5204
0.4000
0.2000
0.0000
16
Submission
32
48
Slide 14
64
80
n
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls
Submission
Slide 15
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD
• Straw Poll-1: add the following sentence to section 5 Frame
Formats of TGaq SFD, 11-13-0300r1
• 802.11aq shall define a IE with service hash bitmap for service indication.
– Result
•Yes
•No
•Need more info
Submission
Slide 16
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD – con’t
• Straw Poll-2: add the following sentence to section 5 Frame
Formats of TGaq SFD, 11-13-0300r1
• 802.11aq shall define a new public action frame for service query.
– Result
•Yes
•No
•Need more info
Submission
Slide 17
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD – con’t
• Straw Poll-3: add the following sentence to section 7 MLME of
TGaq SFD, 11-13-0300r1
• 802.11aq shall define mechanism to provide service indication from AP
with service hash bitmap and service protocol bitmap in Beacon and Probe
Response
– Result
•Yes
•No
•Need more info
Submission
Slide 18
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD – con’t
• Straw Poll-4: add the following sentence to section 7 MLME of
TGaq SFD, 11-13-0300r1
• 802.11aq shall define mechanism to provide general service query for a
STA to decide the availability of a service from AP before association.
– Result
•Yes
•No
•Need more info
Submission
Slide 19
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD – con’t
• Straw Poll-5: add the following sentence to section 7 MLME of
TGaq SFD, 11-13-0300r1
• 802.11aq shall define mechanism to provide detailed service query for a
STA to get the detailed information of a service from AP before
association.
– Result
•Yes
•No
•Need more info
Submission
Slide 20
Ping FANG, Huawei
Nov 2013
doc.: IEEE 802.11-13/1403r0
Straw Polls on Proposed Text to SFD – con’t
• Straw Poll-6: add the following sentence to section 8 Security of
TGaq SFD, 11-13-0300r1
• 802.11aq shall define mechanism to provide privacy for pre association
service queries with different hash values for a service in service query
request and response.
– Result
•Yes
•No
•Need more info
Submission
Slide 21
Ping FANG, Huawei