1. Simplified DLS Action Frame Transmission in 11Z
September 2007
doc.: IEEE /2376r0
Dec 2007
Simplified DLS Action Frame Transmission in 11Z
Date:
Authors:
L.Chu Etc.
Steve Emeott, Motorola

2. Simplified direct link setup frame transmission
September 2007
doc.: IEEE /2376r0
Dec 2007
Simplified direct link setup frame transmission
Solution to frame reordering
L.Chu Etc.
Steve Emeott, Motorola

3. Tunneled Direct Link Setup (TDLS) in [1]
Dec 2007
Tunneled Direct Link Setup (TDLS) in [1]
TDLS action frames are encapsulated in data frames as data frame payload.
Encapsulated TDLS action frames go through an AP path from STA1 to STA2
An AP transparently forwards encapsulated TDLS management action frames.
An AP is unaware of TDLS management frames that it forwards!
Octets:
24/26 6 1 1
Variable 4
MAC Data
Header
LLC/SNAP
Remote Frame
Type
TDLS Packet
Type
TDLS Information
FCS
Data Frame Payload AP
AP Path 1b 1a 2a 2b
Direct Link
STA1
STA2
L.Chu Etc.

4. Dec 2007
Problems with TDLS
MAC layer entity in a STA has to analyze the ethertype octet at the link layer in each data frame that it accepts.
It violates IEEE 802 architecture.
It puts much overhead on the MAC layer entity.
Some overhead is put in AP.
An AP has to forward TDLS action frames. AP
AP Path 1b 1a 2a 2b
STA1
STA2
Direct Link
L.Chu Etc.

5. Simplified Direct Link Setup Frame Transmission
Dec 2007
Simplified Direct Link Setup Frame Transmission
New DLS action frames are defined with new action type.
New DLS action frames are sent between two STAs directly
New DLS action frames are not encapsulated in MAC data frames.
An AP does not forward the proposed DLS action frames.
Octets: 24 1 1
Variable 4
Management
Frame Header
Category
Action
Value
TDLS Information
FCS
Management Frame Payload AP
New DLS action frame path.
AP Path 1
STA1
STA2
Direct Link Path 2
L.Chu Etc.

6. PROs of Simplified DLS Frame Transmission
Dec 2007
PROs of Simplified DLS Frame Transmission
PROs
This method does not violate the 802 architecture.
This method does not need a new ethertype octet.
The MAC entity does not need to analyze ethertype in each data frame!
An AP does not forward the proposed DLS action frames. AP
SDLS action frame path.
AP Path 1
STA1
STA2
Direct Link Path 2
L.Chu Etc.

7. Simplified direct link setup frame transmission
September 2007
doc.: IEEE /2376r0
Dec 2007
Simplified direct link setup frame transmission
Solution to frame reordering
L.Chu Etc.
Steve Emeott, Motorola

8. Solution to Frame Reorder
Dec 2007
Solution to Frame Reorder
When STA1 sends a Tx Path Switch Request with the direct path indication, it shall stop transmitting frames to STA2 through the AP. STA1 shall buffer the frames to STA2.
When STA1 receives a Tx Path Switch Response with the direct path indication, it starts a delay timer.
When the delay timer times out, STA1 starts to transmit frames to STA2 through direct link path. AP
AP Path
STA1
STA2
Direct Link Path
L.Chu Etc.

9. Dec 2007
Reference
[1] 11-07/2515r8, Tunneled Direct Link Setup (TDLS), Menzo Wentink etc.
L.Chu Etc.