1. Two step service discovery for TGaq
April 2013
doc.: IEEE /0796
September 2013
Two step service discovery for TGaq
Date:
Authors:
Ping FANG, Huawei
Ping FANG, Ping FANG, Huawei

2. April 2013
doc.: IEEE /0426
September 2013
Abstract
This document is intended to facilitate further discussions on pre-association service discovery from STA’s side. A high level 2-step service discovery procedure is proposed. And service indication is discussed with more details.
Ping FANG, Huawei
RYU Cheol. ETRI

3. April 2013
doc.: IEEE /0426
September 2013
Background
In 13/501r0 of Hawaii meeting, we presented a architecture with service registration and service discovery. Per the meeting discussion, the registration can be done in MAC layer or upper layer after association.
In 13/796r0, we focus on the left side of the architecture, the procedure on how a STA discovers necessary service information before association. A high level 2-step service discovery procedure is proposed.
In this revision, we provide more details on service indication based on Geneva meeting discussion.
Ping FANG, Huawei
RYU Cheol. ETRI

4. Recapture: Two step service discovery
September 2013
Recapture: Two step service discovery
S2: Detailed Service Query
Based on Service Indication
Services
from Network
STA
GAS AP
STA
Service Record
Services
from associated
device
S1: AP/Network Discovery + Service Indication
Service Indication
Service Indication, e.g. Service Bitmap
Beacon
Probe
Probe
response
Ping FANG, Huawei

5. Two step procedure for PAD
April 2013
doc.: IEEE /0426
September 2013
Two step procedure for PAD
Step 1: Service Indication with AP/Network Discovery
STA indicates Service to be queried in Probe Req
AP indicates Service provided in Probe Resp and Beacon
Step 2: Detailed Service Query
STA send GAS to query detailed service information
Assumption:
AP has a record of Service that can be provided by backhaul or associated STAs
Service can be indicated in Probe Req, Probe Resp, Beacon
GAS will be extended to support service query
Ping FANG, Huawei
RYU Cheol. ETRI

6. April 2013
doc.: IEEE /0426
September 2013
Service indication
Service Information can be carried in Probe Req/ Resp, to indicate a service
A Service bitmap to be carried in Beacon to indicate Service
Each bit in bitmap corresponding to a Hash value of a service name
Multiple Service may map to one bit, need further query to clarify
Service Hash can be future compatible, easy to extend
Ping FANG, Huawei
RYU Cheol. ETRI

7. Service Indication IE Interworking IE in beacon in 11u Hints to 11aq:
April 2013
doc.: IEEE /0426
May 2013
Service Indication IE
Interworking IE in beacon in 11u
Element ID
Length
Access Network Options
Venue Info (Optional)
HESSID (Optional)
1 octet
0 or 2 octet
0 or 6 octet
Access Network Type
Internet
ASRA
ESR
UESA
B0~B3 B4 B5 B6 B7
Hints to 11aq:
Similar mechanism can be used for Service Indication
Service Indication IE in Beacon/ Probe Response
ASRA: additional step required for access
ESR: emergency services reachable
UESA: unauthenticated emergency service accessible
Element ID
Length
Service indication bitmap
1 octet
TBD octet
Ping FANG, Huawei
RYU Cheol. ETRI

8. Service Indication IE for 11aq
April 2013
doc.: IEEE /0426
May 2013
Service Indication IE for 11aq
Option 1: Indicate protocol supported
UPnP, Bonjour, Wi-Fi Direct Service etc, several bits can be enough
No information of service in protocol, further query is necessary
Option 2: Indicate service information
The length of indication information could be long, e.g., 128 bit, 256 bit
Not flexible for new services
Option 3： Indicate service information with hash
Calculate hash value of service information, and map it to bit map, Hash( “2Dprinter”) is mapped to bit 1, Hash(“3Dprinter”) is mapped to bit 2
Protocol can be part of the hash, e.g., UPnP’s printer service named “UPnP:printer”, and hashed to bit 1.
UPnP
Bonjour … …
Option 1 1 1 …
Bit 1
Bit 2
Bit 3
Bit 4
Bit 1
Bit 2
Bit 3
Bit 4
Option 3
Printer
Scanner
Hash(“UPnP:Printer”), then set bit 1 value to be 1.
Option 2 1 …
Bit 1
Bit 2
Bit 3
Bit 4
Ping FANG, Huawei
RYU Cheol. ETRI

9. Summary Proposed a two step service discovery scheme
September 2013
Summary
Proposed a two step service discovery scheme
AP caches service information
Service is indicated during AP/Network discovery
Hash value of service is suggested for scalability
Further service information is queried with GAS extension
Ping FANG, Huawei

10. References IEEE Std 802.11™-2012 11-13-0057-02-00aq-design-options
September 2013
References
IEEE Std ™-2012
aq-design-options
aq-service-registration-of-sta-to-an-ap
Ping FANG, Huawei