1. Non contiguous 40+40 MHz mode for Europe, Japan and global
Month Year
doc.: IEEE yy/xxxxr0
Non contiguous MHz mode for Europe, Japan and global
Date:
John Doe, Some Company

2. Content The following modes have already been accepted by 11ac
20MHz, 40MHz, 80MHz (mandatory)
Contiguous and non contiguous 160MHz (optional)
Optional 40+40MHz non contiguous transmission mode should be added to the spec framework especially for Europe, Japan and Global operating class tables
it enables to exploit the part of the band left aside by the current contiguous 80MHz frequency planning
it increases the probability to transmit at 80MHz (the target of 11ac) in presence of neighboring BSS or radars
its complexity is identical to the 80+80MHz mode already accepted by TGac

3. 80MHz Channel planning in 5GHz band
Weather radars
5170
MHz
5330
MHz
5490
MHz
5710
MHz
5735
MHz
5835
MHz 36 40 44 48 52 56 60 64
100
104
108
112
116
120
124
128
132
136
140
149
153
157
161
165
IEEE channel #
20 MHz
40 MHz
80 MHz
only in US
Only 4 channels for 80MHz in Europe/Japan/Global, only 2 at 30dBm
If a weather radar is active, one channel (in red) is denied, reducing the number of available channels to 3
In many cases, contiguous only BSS will not be able to transmit at 80MHz without overlapping
Non contiguous 40+40MHz mode is the solution in this part of the band
each 40MHz segment is allocated in the band according to 40MHz channel planning
Slide 3

4. Neighboring BSS issue
Neighboring BSS is an issue in big cities of Europe/Japan/Global because the density of population is high (>3000 people per sqKm)
Europe:
Japan
USA
Source :
Slide 4

5. Typical example of fragmented usage of 5GHz band in Europe/Japan
Weather radars
5170
MHz
5330
MHz
5490
MHz
5710
MHz 36 40 44 48 52 56 60 64
100
104
108
112
116
120
124
128
132
136
140
IEEE channel #
20 MHz
Load < 20%
40 MHz
Load > 80%
80 MHz
In red colour, the 20MHz channels (48, 60, 100, 116 and 136) with a high load (neighboring a and n APs)
If a new ac AP is looking for 80MHz bandwidth …
Contiguous 80MHz transmission is disrupted due to high loaded channels (load > 80%)
Contention with neighboring APs and channel access is deferred
Non contiguous 40+40MHz transmission is assured thanks to low loaded channels (load < 10%)
Four 40MHz non contiguous channels are available !!!

6. Extension of the existing non-contiguous mode
Non contiguous 40+40MHz mode could be paired with in the non contiguous MHz mode
Chipsets with the non contiguous option could target 2 markets:
Low density areas when using MHz
High density areas when using MHz
Non contiguous 40+40MHz mode provides a high throughput experience for end-user in dense areas instead of a fallback of 40MHz mode ("802.11n like" behavior)
Focus for cities with high density of overlapping BSS
In the case where MU-MIMO is not applicable
Flexibility to choose (primary-secondary) and (tertiary-quaternary) channels
The case where the two 40Mhz segments are adjacent is excluded
Fallback to the 80Mhz contiguous mode

7. Conclusion
40+40MHz non contiguous transmission mode should be added to the spec framework as an optional feature for Europe/Japan/Global
Areas with less channels and high density of population
it enables to exploit the part of the band left aside by the current contiguous 80MHz frequency planning
it increases the probability to transmit at 80MHz (the target of 11ac) in presence of neighbors or radars..
it does not imply any additional complexity for devices supporting the 80+80MHz mode already accepted by TGac

8. Pre-motion
Do you support adding the following section and item into the specification framework document, 11-09/0992?
Section 3.1.D Non contiguous 160 MHz PHY Transmission
R3.1.D.1: The draft specification shall include support for non contiguous 40+40MHz PHY transmission, whose frequency spectrum consists of two segments, necessarily non-adjacent in frequency, each transmitted using one 40 MHz channel, for devices supporting non contiguous 160 MHz.
Yes:
No:
Abstain:

9. References
[1] Cariou, L. and Christin, P., Non contiguous additional bandwidth mode, IEEE /1159r1, Sept 2010
[2] Cariou, L. and Christin, P., 80MHz and 160MHz channel access modes, IEEE /0385r1, Mar. 2010
[3] Cariou, L. and Benko, J., Gains provided by multichannel transmissions, IEEE /0103r1, Jan. 2010