1. Design Option for Service Discovery Mode
April 2013
September 2013
Design Option for Service Discovery Mode
Date:
Authors:
RYU Cheol, ETRI
RYU Cheol. ETRI

2. April 2013
September 2013
Abstract
This presentation extends a design option and suggests a service discovery mode which adopts a synchronized broadcasting or multicasting scheme in a common channel. A few straw polls are following the suggestion to develop the design option further.
RYU Cheol, ETRI
RYU Cheol. ETRI

3. September 2013
One Common Channel
TGaq has discussed on ‘a common channel’ as a design option. On the common channel service information is broadcasted or multicasted.
One common channel has a few good characteristics while considering following issues;
Possibility of service discovery on a common channel would be greater than a few social channels and all channels.
It seems possible that the synchronized broadcasting is possible in a common channel
typically has two PHYs, 2.4G and 5G. A channel in 2.4G frequency looks good for service discovery. …
RYU Cheol, ETRI

4. Public Action Frame for Broadcasting/Multicasting
September 2013
Public Action Frame for Broadcasting/Multicasting
PAM n
PAM n+1
PAM n+2
PAM n+3 AP
30~100 x Beacon Interval
AP broadcasts PAM(Pre-Association Message) in a public action frame with a long interval (e.g. 30 or 100 times of Beacon Interval.)
The PAM includes;
BSS information (operating channel, SSID, and etc.)
summary of available services …
RYU Cheol, ETRI

5. Synchronized Access to a Common Channel
September 2013
Synchronized Access to a Common Channel
In a densely-deployed-AP environment, PAM frames should be synchronized.
STA could wake up for the PAM window in which period the service advertisements are delivered.
AP A
A Common Channel
AP B
PAM
PAM Window
RYU Cheol, ETRI

6. September 2013
Concurrent Mode
AP broadcasts PAM on a common channel c while running a BSS on a operating channel i.
Multiple PHYs are available for networks, one of them could be used for the common channel for service discovery (i.g. 2.4Ghz).
PAM Window could be designed to be a very short period, for running an operating channel in 2.4Ghz.
an operating channel i
Beacon … … … … AP
PAM Interval
a common channel c
PAM
RYU Cheol, ETRI
RYU Cheol. ETRI

7. Service Discovery Mode
September 2013
Service Discovery Mode
STA concurrently listens on a common channel while it is associated or not to a BSS.
GAS Resp.
from AP A
GAS Resp.
from AP B
BSS modes on operating channels
service ad. started
AP A … … … …
Service discovery mode on a common channel c
could be referenced for the concurrent mode, “MultiNet”.
2.4Ghz and 5Ghz are available.
A STA stays on just only service discovery mode, it could go for sleep for power saving.
STA
GAS Query
to AP A
GAS Query
to AP B
awake
sleep
awake
Sleep
(not interested)
awake
Back to
channel c
to listen
Found a service
from AP B
Associated
with AP B
After finding out
interested service
PAM
Beacon
RYU Cheol, ETRI
RYU Cheol. ETRI

8. Straw Poll #1: broadcasting/multicasting scheme
September 2013
Straw Poll #1: broadcasting/multicasting scheme
Do you agree that a broadcasting/multicasting mechanism is a good design option in addition to GAS-based request/response mechanism?
Yes No
Abstain
RYU Cheol, ETRI

9. Straw Poll #2: PAM as a pubic action frame
September 2013
Straw Poll #2: PAM as a pubic action frame
Do you agree that the broadcasted/multicasted PAM in a public action frame is a good design option?
Yes No
Abstain
RYU Cheol, ETRI

10. Straw Poll #3: synchronized access to a common channel
September 2013
Straw Poll #3: synchronized access to a common channel
Do you agree that the broadcasting/multicasting design option requires the synchronized access to a common channel?
Yes No
Abstain
RYU Cheol, ETRI

11. Straw Poll #4: concurrent service discovery mode
September 2013
Straw Poll #4: concurrent service discovery mode
Do you think the concurrent service discovery mode could address a technical solution for the power consumption issue for service discovery?
Yes No
Abstain
RYU Cheol, ETRI