1. 120MHz channelization solution
Month Year
doc.: IEEE yy/xxxxr0
Nov. 2010
120MHz channelization solution
Date:
Authors:
LvKaiying, ZTE Corporation
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
Nov. 2010
Abstract
Current specification support an efficient channelization in China’s (5,725 ~ 5,850 MHz) spectrum but lack of detailed design
Three 120MHz channelization and operation solutions are proposed in this contribution
Straw Polls
LvKaiying, ZTE Corporation
John Doe, Some Company

3. Nov. 2010
Background .
In last Hawaii meeting, following statements were accepted:
In R3.1.E: The draft specification shall include support for an efficient channelization in China’s (5,725 ~ 5,850 MHz) spectrum.
The following straw poll is accepted but missed in current spec frame: “The total bandwidth of the channels defined for China shall be equal to or not less than 120 MHz”
In China, there’re no many 11n or 11a devices in the market working on 5GHz currently. But before end of 2012, the devices quantity is not predictable.
LvKaiying, ZTE Corporation

4. 120MHz Channelization Approaches
Nov. 2010
120MHz Channelization Approaches
Approach 1
Shifted 20MHz, 40MHz, and 80MHz channels and one optional 120MHz channel
7.5MHz left shifted center frequency allows six 20 MHz channels and three 40 MHz channels
No change to current 20MHz, 40MHz and 80MHz signal design
Need to define a new 120MHz signal, which could allow a combination of current channels or a complete 120MHz channel signal.
Approach2
Non-shifted 20MHz, 40 MHz and 80 MHz channels as current 20MHz, 40MHz and 80MHz design
One optional 120MHz channel
LvKaiying, ZTE Corporation

5. Channelization Approach 1
Nov. 2010
Channelization Approach 1
7.5MHz
5735
40MHz
80MHz
20MHz
5727.5
5847.5
f MHz
120MHz
5835
12.5MHz
Legacy mode
Enhanced mode
LvKaiying, ZTE Corporation

6. Solution A based on channelization approach 1
Nov. 2010
Solution A based on channelization approach 1
802.11ac AP starts a BSS alternatively operating on shifted and non-shifted channels in time domain, with two primary channels defined for shifted channel set and non-shifted channel set.
802.11ac AP alternatively sends beacons and other control & management frames on shifted and non-shifted channels in time domain.
Legacy STAs access and associate with ac AP in non-shifted channels.
802.11ac STAs can access and associate with ac AP in either shifted or non–shifted channels.
CFP/CP window parameters are configured to guarantee no time confliction between transmission on two channel sets.
LvKaiying, ZTE Corporation

7. Solution A based on channelization approach 1
Nov. 2010
Solution A based on channelization approach 1
LvKaiying, ZTE Corporation

8. Solution A Analysis Coexistence Backward compatibility
Nov. 2010
Solution A Analysis
Coexistence
OBSS scanning before and after BSS establishment
AP Alternatively scans OBSS in shifted and non-shifted channels to detect OBSS overlapping.
STAs perform OBSS scanning in shifted and non-shifted channels and report to AP
AP may shift to other channels to avoid interference to the existing OBSS.
Backward compatibility
The legacy mode (non-shifted channelization) can be used to support legacy devices.
120MHz Transmission (optional)
The enhanced mode (shifted channelization) can provide 120MHz data transmission when all 6 20MHz channels are idle.
LvKaiying, ZTE Corporation

9. Challenges to Solution A
Nov. 2010
Challenges to Solution A
Regulatory extension for 5.7GHz for Chinese spectrum.
120MHz channel definition with
New preamble design
New pilot design
New sub-carrier sequence design
RF front-end implementation design
Interference control
Complex OBSS scanning for overlapped & non-orthogonal channels
LvKaiying, ZTE Corporation

10. Channelization Approach 2
Nov. 2010
Channelization Approach 2
7.5
5735
40MHz
80MHz
20MHz
5727.5
5847.5
f MHz
120MHz
5835
12.5
Legacy mode
120MHz mode
LvKaiying, ZTE Corporation

11. Channelization Approach 2
Nov. 2010
Channelization Approach 2
Current design for 20/40/80MHz transmission
New 120MHz design for potential 120MHz channel for data-only transmission
120MHz data transmission is available only when five non-shifted 20 MHz channels are detected as idle by both initiator and responder
Quintuplicate RTSs/CTSs are transmitted in five non-shifted 20 MHz channels to reserve 120MHz channel
Quintuplicate ACKs are transmitted in five 20 MHz channels
Possible methods for 120MHz data transmission detection
by preamble detecting on five 20MHz channels [preferred]
by 120MHz bandwidth information indicated in RTS/CTS frame
by explicitly phased division to indicate 120MHz transmission
LvKaiying, ZTE Corporation

12. Channelization Approach 2
Nov. 2010
Channelization Approach 2
LvKaiying, ZTE Corporation

13. Solution B based on channelization approach 2
Nov. 2010
Solution B based on channelization approach 2
Basically burst-style time division of legacy transaction period and 120MHz data only transmission period
Only data frames and some management frames transmitted with 120MHz bandwidth;
Control frames and most networking joining related management frames transmitted with current channels.
LvKaiying, ZTE Corporation

14. Solution C based on channelization approach 2
Nov. 2010
Solution C based on channelization approach 2
Allow phased division of legacy transaction period and 120MHz data only transmission period
AP controlled or STA requested phased division of legacy transaction period and120MHz data only transmission period
CCA detection on 5 non-shifted 20MHz channels. If all 5 channels are idle, then AP sends CTS-to-self on 5 non-shifted 20MHz channels to reserve 100MHz channel
After120MHz transaction phase starts, AP and 120MHz recipient STAs exchange RTS/CTS on 5 legacy 20MHz channels to avoid OBSS interference
LvKaiying, ZTE Corporation

15. Challenges to channelization approach 2
Nov. 2010
Challenges to channelization approach 2
120MHz channel definition with
New preamble design
New pilot design
New sub-carrier sequence design
RF front-end implementation design
RTS detection by preamble detection on five 20MHz channels
LvKaiying, ZTE Corporation

16. Nov. 2010
Strawpoll #1
Do you support adding the following text into the specification framework document, 15-09/0992?
"when 120MHz bandwidth is implemented, e.g. in China, an 11ac device shall support a shifted 20/40/80MHz channelization and a possible 120MHz channelization.”
Yes:
No:
Abstain:
LvKaiying, ZTE Corporation

17. Nov. 2010
Strawpoll #2
Do you support adding the following text into the specification framework document, 15-09/0992?
“when 120MHz bandwidth is implemented, e.g. in China, an 11ac device shall support a non-shifted 20/40/80MHz channelization and a possible shifted120MHz channelization.”
Yes:
No:
Abstain:
LvKaiying, ZTE Corporation

18. Nov. 2010
Strawpoll #3
Do you support adding the following text into the specification framework document, 15-09/0992?
“To provide co-existence among 11ac devices and 11n/11a devices when 120MHz bandwidth is implemented, e.g. in China, a ac AP shall starts a BSS alternatively operating on shifted and non-shifted channels in time domain.”
Yes:
No:
Abstain:
LvKaiying, ZTE Corporation

19. Nov. 2010
Strawpoll #4
Do you support adding the following text into the specification framework document, 15-09/0992?
“when 120MHz bandwidth is implemented, e.g. in China, a 11ac STA could transmit a data frame using a 120MHz signal.”
Yes:
No:
Abstain:
LvKaiying, ZTE Corporation

20. Nov. 2010
Thank you!
LvKaiying, ZTE Corporation