submission doc.: ieee 11-13/1057r0 september 2013 jinyoung chun et. al, lg electronicsslide 1 legacy...
TRANSCRIPT
Submission
doc.: IEEE 11-13/1057r0September 2013
Jinyoung Chun et. al, LG ElectronicsSlide 1
Legacy Support on HEW frame structure
Date: 2013-09-16
Name Affiliations Address Phone email Jinyoung Chun LG Electronics Seoul, Korea +82-2-6912-
6588 [email protected]
Wookbong Lee LG Electronics [email protected]
Jinsoo Choi LG Electronics [email protected]
Dongguk Lim LG Electronics [email protected]
HanGyu Cho LG Electronics [email protected]
Authors:
Submission
doc.: IEEE 11-13/1057r0
Introduction
• This contribution provides requirement for legacy sup-port on HEW frame structure
Slide 2 Jinyoung Chun et. al, LG Electronics
September 2013
Submission
doc.: IEEE 11-13/1057r0
History of legacy support
• In 11n [1],• “Some of the modes of operation defined in the proposal shall be
backwards compatible with 802.11a/g.”• “11n AP can be configured to reject or accept associations from
legacy STA because they are legacy STA.”
• In 11ac [2],• “The TGac amendment shall be backwards compatible with
802.11a/n which operates at 5GHz.”• “The TGac amendment shall provide mechanisms that ensure co-
existence between TGac and legacy IEEE802.11a/n devices.”
Slide 3 Jinyoung Chun et. al, LG Electronics
September 2013
Submission
doc.: IEEE 11-13/1057r0
Clarification on legacy support
• Backward compatibility can be interpreted as follows: • New devices shall be able to operate with legacy devices (‘2’ in
the below figure)
• Coexistence can be interpreted as follows:• Legacy AP/STA shall be able to transmit and receive the frames
as the same behavior/procedure regardless of the existence of new AP/STA (‘3’ in the figure)
Slide 4 Jinyoung Chun et. al, LG Electronics
September 2013
new AP
new STA
legacy AP
legacy STA
32
1
Submission
doc.: IEEE 11-13/1057r0
Legacy support in 11n and 11ac (example)
• Backward compatibility– New devices shall be able to operate with legacy devices.
• E.g., .11n device can transmit and receive .11a frames
• E.g., .11ac device can transmit and receive .11a/n frames
• Coexistence– Legacy AP/STA shall be able to transmit and receive the frames as
the same behavior/procedure regardless of the existence of new AP/STA
• This is for CCA behavior
• .11n GF format: Energy detection only
• .11n MF format, .11ac format: Energy detection and Preamble detection
Legacy device can decode new device’s L-STF/L-LTF/L-SIG since it is identical
Slide 5 Jinyoung Chun et. al, LG Electronics
September 2013
Submission
doc.: IEEE 11-13/1057r0
Legacy support on HEW frame structure
• Strictly required to maintain L-Part
• For example, increasing CP length (by increasing FFT size) only in New-Part, does not impact on legacy support.[1],[2]
Slide 6 Jinyoung Chun et. al, LG Electronics
September 2013
VHT-SIG-B
L-Part
L-SIG
L-STF L-LTF11a Data
11n (HT)
L-SIG
L-STF L-LTF DataHT-LTF
HT-SIGHT-STF
HT-LTF
...
11ac (VHT)
L-SIG
L-STF L-LTF DataVHT-LTF
VHT-SIG-AVHT-STF
VHT-LTF
...
L-SIG
L-STF L-LTF HEW-Preamble/Signal/DataHEW
New-Part
Submission
doc.: IEEE 11-13/1057r0
Conclusion
• In this contribution, we provided considerations on legacy support in view of frame structure
• If we keep the L-Part (i.e. L-STF, L-LTF, and L-SIG) in HEW frame, we can design New-Part freely such as in-creasing CP length with no harm of legacy support.
Slide 7 Jinyoung Chun et. al, LG Electronics
September 2013
Submission
doc.: IEEE 11-13/1057r0
Reference
[1] IEEE 802.11-02/813r11, “802.11 TGn Functional Re-quirements”
[2] IEEE 802.11-09/00451r16, “TGac Functional Re-quirements and Evaluation Methodology”
[3] IEEE 802.11-13-0843, “Further evaluation on outdoor Wi-Fi”
[4] IEEE 802.11-13-0536, “HEW SG PHY Considerations For Outdoor Environment”
Slide 8 Jinyoung Chun et. al, LG Electronics
September 2013